LEARNING ACTIVITY PACKET MECHATRONICS SERVO ROBOTIC ASSEMBLY B72001-AA07UEN

Transcription

1 MECHATRONICS LEARNING ACTIVITY PACKET SERVO ROBOTIC ASSEMBLY B72001-AA07UEN

2 LEARNING ACTIVITY PACKET 7 SERVO ROBOTIC ASSEMBLY INTRODUCTION Automated assembly systems are key components in many mechatronics systems. They automatically assemble parts and move them onto the next step in the process. Servo robots are one type of automated assembly system used in mechatronics. This LAP reviews servo robotic assembly system components, their adjustment, and programming. ITEMS NEEDED Amatrol Supplied 87-MS5 Mechatronics Servo Robotic Station 870-PS7313-AAU, 870-PS7314-AAU, or 870-PS7315-AAU Mechatronics Learning System for Siemens S one per station Siemens S7-300 Programming Cable Siemens Step 7 Programming Software School Supplied Computer with Windows XP Operating System Amatrol or School Supplied Hand Tool Kit or Equivalent FIRST EDITION, LAP 7, REV. B Amatrol, AMNET, CIMSOFT, MCL, MINI-CIM, IST, ITC, VEST, and Technovate are trademarks or registered trademarks of Amatrol, Inc. All other brand and product names are trademarks or registered trademarks of their respective companies. Copyright 2012, 2011 by AMATROL, INC. All rights Reserved. No part of this publication may be reproduced, translated, or transmitted in any form or by any means, electronic, optical, mechanical, or magnetic, including but not limited to photographing, photocopying, recording or any information storage and retrieval system, without written permission of the copyright owner. Amatrol,Inc., 2400 Centennial Blvd., Jeffersonville, IN USA, Ph , FAX

3 TABLE OF CONTENTS SEGMENT 1 STATION OPERATION OBJECTIVE 1 Describe the operation of a servo robotic assembly system OBJECTIVE 2 Describe the operation of a pick and place assembly system OBJECTIVE 3 Describe the operation of a gravity feeder with escapement OBJECTIVE 4 Describe the operation of an automatic screw feeder SKILL 1 Operate a servo robotic assembly station SEGMENT 2 COMPONENT ADJUSTMENT OBJECTIVE 5 Describe how to adjust a parts feeder with escapement SKILL 2 Adjust a parts feeder with escapement OBJECTIVE 6 Describe how to adjust an automatic screw feeder SKILL 3 Adjust an automatic screw feeder OBJECTIVE 7 Describe how to adjust a pneumatic part shuttle SKILL 4 Adjust a pneumatic part shuttle SEGMENT 3 MODULE SEQUENCING OBJECTIVE 8 Describe a sequence of operation of a part insertion module SKILL 5 Design a PLC program that sequences a part insertion module OBJECTIVE 9 Describe a sequence of operation of a screw feed module SKILL 6 Design a PLC program that sequences a screw feed module OBJECTIVE 10 Describe a sequence of operation of a screw thread engagement module SKILL 7 Design a PLC program that sequences a screw thread engagement module SEGMENT 4 STATION SEQUENCING OBJECTIVE 11 Describe a sequence of operation of a servo robotic assembly station SKILL 8 Design a PLC program that sequences a servo robotic assembly station OBJECTIVE 12 Describe the operation of a servo robotic assembly station with manual/ auto/reset functions SKILL 9 Design a PLC program that provides manual/ auto/ reset functions for a servo robotic assembly station 3

4 SEGMENT 1 STATION OPERATION OBJECTIVE 1 DESCRIBE THE OPERATION OF A SERVO ROBOTIC ASSEMBLY SYSTEM A servo robotic assembly system performs a sequence of automated assembly operations to join two or more parts into one assembly. This type of system uses one or more assembly workstations, part feeders, and a robot for component handling. Figure 1. Robotic Assembly A typical servo robotic assembly system uses a robot to retrieve parts from other processing stations or from parts feeders and may use it for some of the assembly process. The robot places the parts in the assembly fixture and then moves to a clear position. Once the robot is clear, the assembly fixture takes over and performs tasks such as insert fasteners, weld or glue parts together, or install components on circuit boards. The robot may be used to move subassemblies from one assembly module to another. Once the assembly is complete, the robot removes the finished part to a storage location or to another station for further processing. 4

5 In a robotic assembly system the robots are often interfaced to other intelligent controllers to enable them to coordinate operations. One common application is a multi-station conveyor system that transports parts to workstations where robots perform tasks to create a product. Typically, a PLC controls the movement of pallets containing raw material on the conveyor, stopping them at various stations. When a pallet arrives at a workstation, the conveyor PLC sends a signal to the robot controller to tell it to begin operations at the station. When the operation at the station is finished, the robot controller sends a signal back to the conveyor PLC to tell it that it has completed operations. BEARING INSERT ROTOR ASSEMBLY REAR HOUSING ASSEMBLY SCREW FASTENING VIBRATION BOWL FEEDER #2 #3 #4 #5 #1 PLC CELL CONTROL FINISHED PRODUCT FEED BASE HOUSING FEED STATION Figure 2. Robotic Assembly System 5

6 OBJECTIVE 2 DESCRIBE THE OPERATION OF A PICK AND PLACE ASSEMBLY SYSTEM Pick and place assembly systems use manipulators to lift, move, and place objects in desired locations. These manipulators pick parts from feeders or bins and place them directly on the assembly or in position for assembly by other automated equipment. The assembly performed by a pick and place system may include placing fasteners, components on circuit boards for surface mount technology (SMT), or applying adhesive for component placement. Once the assembly is complete, the pick and place device typically removes the assembly to a material transfer device or to another station for further processing. 2-AXIS MANIPULATOR WITH ROTATING GRIPPER PART HOLDING TRAYS ASSEMBLY WORK SURFACE PART HOLDING TRAYS Figure 3. Pick and Place Assembly System Pick and place assembly systems are typically controlled by a PLC, often using solenoid-operated pneumatic or hydraulic valves to control machine movements, although they can be servo-controlled as well. Because pick and place systems have limited program positions, pick and place assembly systems are used for sequential assembly operations, where each pick and place device performs one step of a multiple step automated assembly process. 6

7 OBJECTIVE 3 DESCRIBE THE OPERATION OF A GRAVITY FEEDER WITH ESCAPEMENT Gravity feeders hold parts for use by the assembly process. When the bottom part is removed, gravity causes the rest of the parts to drop down. Some gravity feeders include an escapement, which is a device that allows parts to be fed one at a time into the process. One example of an escapement is shown in figure 4. This escapement uses a flexible tab to hold back the parts. When the work carriers pass, they catch the bottom of the part with enough force to push it from the feeder into the work carrier. As this occurs, gravity forces the other parts to move down. ESCAPEMENT FEED TRACK PARTS PART CARRIERS Figure 4. Gravity Part Feeder with Escapement Another example of an escapement is a dual pneumatic cylinder type, shown in figure 5. The first cylinder (A) holds the bulk of the parts back. It retracts and releases one part at a time to the second cylinder (B). Once cylinder A is extended again, cylinder B can retract and release the part to the process. This prevents multiple parts from falling into the process. This type of escapement also works well on conveyor-style feeders. STEP 1 A B STEP 3 A B STEP 2 A B STEP 4 A B Figure 5. Dual Pneumatic Cylinder Escapement 7

8 A third example of a gravity feeder escapement is shown in figure 6. In this example, the parts are loaded into a gravity feed chute that allows them to drop down one at a time. The bottom part is exposed to the process and held in place by an adjustable ball-nose spring plunger, which acts as stop or holding point. This stop is a form of an escapement. The part is picked from the feeder by a robot. Once that part is removed, the next part drops into place. GRAVITY FEED CHUTE STOP ESCAPEMENT PART Figure 6. Gravity Feeder with Stop Escapement 8

9 OBJECTIVE 4 DESCRIBE THE OPERATION OF AN AUTOMATIC SCREW FEEDER An automatic screw feeder feeds screws or bolts into a process. One example is the pneumatic valve assembly process shown. Some screw feeder designs may use multiple cylinders to ensure proper positioning of the screws. A sensor is often positioned to read when the feeder is out of parts, sending a signal to the PLC to stop the sequence until more parts are put in the feeder. Figure 7 shows an example of an automatic screw feed application. This application uses three cylinders (1, 2, and 3) to restrain and release the screws, which are fed into the system through a vinyl tube filled with compressed air. Cylinders 1 and 2 operate the screw guide and restraint mechanism. Cylinder 3 prevents the next screw in line from feeding during the insertion process. Timers in the PLC program controls this process. PRESSURE REGULATOR SCREW FEED CAP SCREWS S SCREW READY TO BE PUSHED INTO VALVE BODY DIAL INDICATOR HOSE PART SENSOR FLOW CONTROL VALVES Figure 7. Automatic Screw Feeder 9

10 Figure 8 shows the operation of the screw feed cylinders. When the system is started, step 1, cylinder 1 is retracted and cylinder 2 is extended, closing the screw guide and restraining the first screw in line in position. A portion of the screw extends beyond the feeder and into the assembly area. Cylinder 3 is also retracted at this time. When the PLC calls for a screw, step 2, the first screw insertion timer starts and the screw insertion solenoid valve is energized. Energizing the solenoid causes cylinder 3 to extend to trap the second screw in line under the screw head. At the same time, cylinder 1 extends and cylinder 2 retracts, opening the screw guide, as shown in Step 3. At this point, the first screw is partially inserted into the assembly and the second screw is held back by cylinder 3. This is when the first screw insertion timer ends and a second timer starts. The screw insertion solenoid valve is de-energized, shown in Step 4, which sends the screw feed cylinders back to their home positions. Cylinder 1 retracts and cylinder 2 extends to once again close the screw guide and restrain the next screw in line. Cylinder 3 retracts, allowing the next screw in line to move into the screw guide and at the same time push the first screw all the way into the assembly. STEP 1 1 STEP 2 2 ASSEMBLY 1 2 SCREW EXTENDS INTO ASSEMBLY AREA SCREW GUIDE FIRST SCREW SECOND SCREW 3 SCREW GUIDE STEP 3 STEP EXTENDS TO CATCH SECOND SCREW UNDER THE HEAD SCREW GUIDE OPENS SCREW HELD IN PLACE 3 END OF SCREW PUSHES FIRST SCREW INTO ASSEMBLY SCREW GUIDE CLOSES RETRACTS SECOND SCREW EXTENDS INTO SCREW GUIDE Figure 8. Automatic Screw Feeder Operation 10

11 The screw feeder cylinders are regulated using the flow control valves mounted on the cylinders. By regulating each individual cylinder, the speed at which the screw is released and fed into the part is controlled. Some cylinders, such as the ones shown in figure 9, are used together to perform one task, so their speed for both extend and retract should always be the same. 1/2 OF SCREW GUIDE CONTROLLED BY TOP FLOW CONTROL VALVE 1 3 1/2 OF SCREW GUIDE CONTROLLED BY BOTTOM 2 FLOW CONTROL VALVES Figure 9. Cylinder Pair 11

12 SKILL 1 OPERATE A SERVO ROBOTIC ASSEMBLY STATION Procedure Overview In this procedure, you will start up and operate the 87-MS5 Servo Robotic Assembly station of the 870 Mechatronics System. 1. Locate the 87-MS5 Servo Robotic Assembly station, shown in figure 10. Your system may have a Pegasus robot, as shown on the left side of figure 10, or a Saturn robot as shown on the right side of figure 10. Figure MS5 Servo Robotic Assembly Station 2. Verify that this station has been separated from any other stations. If it has not, then proceed with Step 3 to separate it from the other station. If it has, then proceed to Step Perform the following substeps to separate the Servo Robotic Assembly station from the other stations. A. Remove the power cord from the wall outlet. B. Remove the adjoining unit s power cord. C. Remove the adjoining unit s pneumatic hose. D. Disconnect the 9-pin to 9-pin cable from the other unit(s). 12

13 E. Loosen the connecting fasteners that hold the work surfaces together by turning the wing nuts CCW. F. Push the station away from the other stations to give yourself room to work. Figure MS5 Servo Robotic Assembly Station Separated From Other Stations 4. Perform the following safety check before you begin working on the station. Make sure that you can answer yes to each item before proceeding. YES/NO Figure 12. SAFETY CHECKOUT Remove all obstructions from the work area Check for signs of damage to the equipment Wear tight fi tting clothing, roll up long sleeves, remove ties, scarves, jewelry, etc. Tie up long hair Remove any robot teach pendants from the work area Locate the emergency stop button Ensure that safety glasses are worn by people in the area Ensure that all people are outside any work envelopes Mechatronics Safety Check 13

14 5. Perform the following substeps to install the Feed Stand. The feed stand is used when the 87-MS5 is separated from the other stations to hold the valve bodies so the robot can easily pick them up. A. Obtain the Feed Stand and mounting hardware, (3) 1/4-20 x 3/8-inch button head cap screws and (1) triple T-nut, shown in the top of figure 13, from your instructor. If you have the single feed stand, you will have a double t-nut and (2) 1/4-20 x 3/8-inch button head cap screws, as shown in the bottom of figure 13. The installation instructions that follow show the double feed stand, but applies to the single as well. DOUBLE FEED STAND TRIPLE T-NUT 1/4-20X3/8 IN. BUTTON HEAD CAP SCREWS SINGLE FEED STAND DOUBLE T-NUT Figure 13. Feed Stand 14

15 B. Loosen either the front or rear end cap from the left side (as you are facing the control panel) of the work surface by prying it off, as shown in figure 14. A screwdriver may be required as the end cap may have a tight fit. Figure 14. Loosen the End Cap C. Slide the triple T-nut along the inside of the aluminum extrusion so that it is positioned in line with the assembly fixture, as shown in figure 15. TRIPLE T-NUT Figure 15. Position the Triple T-Nut 15

16 D. Position the feed stand as shown in figure 16 so the holes in the bottom flange line up with those in the triple T-nut. TRIPLE T-NUT BOTTOM OF FEED STAND Figure 16. Feed Stand Position E. Insert the screws through the outside of the feed stand so that the threads engage the T-nut, and tighten the screws by using a 7/16-inch hex wrench and turning them CW until snug so the feed stand is secure. FEED STAND Figure 17. Insert Screws BUTTON HEAD CAP SCREWS 16

17 F. Replace the end cap on the end of the work surface. FEED STAND Figure 18. Mounted Feed Stand 6. Perform the following substeps to install the parts bin, shown in figure 19. The parts bin is used when the station is separated from the other stations to catch the parts as the robot drops them. A. Obtain the red plastic parts bin, mounting bracket, and (2) 1/4-20 x 1/2 thumbscrews and (2) single T-nuts, shown in figure 19. BIN MOUNTING BRACKETS THUMBSCREWS T-NUTS Figure 19. Parts Bin, Mounting Bracket, and Mounting Hardware 17

18 B. Loosen the end cap on the right side of the work surface (as you are facing the station) by prying it off, as done in the previous step. A screwdriver may be required as the end cap may have a tight fit. C. Slide the two t-nuts along the inside of the aluminum extrusion so that they are positioned in line with the end of the knob/spring assembly fixture. FIXTURE END OF TRANSFER T-NUTS Figure 20. Position the Single T-Nuts D. Position the mounting bracket so it is in line with the work fixture, as shown in figure 21. E. Use a screwdriver to position the T-nuts so they are in line with the holes in the mounting bracket. 18

19 F. Insert the thumbscrews through the outside of the bracket so that the threads engage the T-nuts. Then tighten the thumbscrews by turning them CW until snug so the bracket is secure. The T-nuts have a tendency to angle back away from vertical, so this step may take several tries. WORK FIXTURE Figure 21. Positioning of Bracket G. Replace the end cap on the end of the work surface. H. Attach the parts bin to the top of the mounting bracket. Figure 22. Parts Bin Mounted to the Mounting Bracket 19

20 7. Connect an air supply to the station s air manifold quick connect. 8. Plug the station s power cable into a wall outlet. 9. Perform the following substeps to power up the 87-MS5 Servo Robotic Assembly station. A. Place the Mode Selector switch in the Manual position. B. Remove the lockout/tagout device from the electrical power source. C. Remove the lockout/tagout device from the pneumatic power source. D. Turn on air to the station by shifting the lever on the lockout valve. E. Set the station s air supply regulator to 50 psi/345 kpa. F. Set the screw feed module s air supply regulator to 12 psi/82.7 kpa. G. Turn the station s Main Power switch to the On position. 10. Perform the following substeps to open the PLC programming software. A. Make sure that the interface from the personal computer to the PLC is connected. B. Power up the PC and monitor. C. Start the SIMATIC Manager. 11. Perform the following substeps to open project Robotic Assembly Station. A. Click the Open Project/Library button. The Open Project/Library dialog should open. B. Locate project Servo Robotic Assembly. The project Servo Robotic Assembly Station was provided on a supplemental disk. If it is not listed on the dialog, click the Browse button on the dialog to view the projects located in the S7Proj folder. C. Double-click the Servo Robotic Assembly icon to open the project. D. Select Expand All from the View menu to expand the project s contents. The option is Expand All if using STEP 7 Version 5.2 or Show All Levels if using STEP 7 Version 5.3. NOTE The air on this station may be loud, so once you set the air supply regulators, you may want to shift the lever on the lockout valve until you reach step

21 12. Perform the following substeps to download the project Servo Robotic Assembly to the PLC. A. Place the PLC s Mode Selector switch in the RUN position. B. Reset the PLC. C. Select the SIMATIC 300 Station object by clicking it so that it is highlighted. D. Click the Download button to download the project to the PLC. Several dialogs will appear during the download. Click the appropriate response to continue downloading the program. The last dialog should ask if you wish to perform a complete (Warm) restart. E. Click Yes on the dialog to complete a warm restart. 13. Perform the following substeps to stock the parts feeders. A. Obtain from your instructor the screws, spools, and knob/spring assemblies used in the valve assembly. B. Remove the cap from the screw feeder, shown in figure 23, by turning it CCW. SCREW FEEDER CAP Figure 23. Screw Feeder Cap C. Insert the screws thread side down into the feeder. D. Place the cap back on the screw feeder by turning it CW until hand tight. 21

22 E. Load the valve spools in the feeder as shown in figure 24. The feeder holds both 3-way and 4-way valve spools, but this skill uses only 3-way. VALVE SPOOL FEEDER Figure 24. Valve Spool Feeder F. Insert the knob/spring assemblies into their feeder, knob side down, as shown in figure 25. KNOB/SPRING ASSEMBLY FEEDER Figure 25. Knob/Spring Assembly Feeder 22

23 14. Press the Output Power pushbutton to enable the PLC s outputs. 15. Perform the following substeps to home the station and set manual mode. A. Verify the lever on the lockout valve is shifted supplying the station with air. B. Turn the Mode Selector switch to Reset. This will home all of the actuators. The Start pushbutton should be off when all of the actuators are in the home position. C. Turn the Mode Selector switch back to Manual. 16. Perform the following substeps to start up the robot. A. Turn on the power to the robot controller B. Turn on the PC connected to the robot controller and start the Robot Control software. C. Open the Mechatronics robot program. This is mech.prg for the Pegasus and Saturn.prg for the Saturn. D. Enable the robot drives. E. Jog the robot to the quick home position. F. Home the robot. 17. Step the robot through its points to verify they are properly adjusted. Figure 26 describes each point location. Figure 27 shows the critical pick-up and placement locations. The approach points should be in a straight line away from the critical points. Note that figure 27 shows more points than what you need for this skill. This is a listing of all of the points used in the robot program, some of which are only used when the stations are connected together. For example, you will not use points 2 or 3 in this skill. These points are applicable to either the Pegasus or Saturn. CAUTION Some of the robot points require that the gripper be closed prior to moving into that position to prevent damage to the hardware. Assess each placement or grip point before moving the robot to that point and close the gripper if necessary. The Saturn, being a larger robot, has less room to maneuver on the assembly station. Make certain the robot speed is very slow when verifying the points. 23

24 POINT Point 1 Point 2 Point 3 Point 4 Point 5 Point 6 Point 7 Point 8 Point 9 Point 10 Point 11 Point 12 Point 13 Point 14 Point 15 Point 16 Point 17 DESCRIPTION Wait Position Approach Aluminum Grip Aluminum Approach Acrylic Grip Acrylic Approach Insertion Position Place at Insertion Position Approach Offload Position Grip at Offl oad Position Approach Torque or Bin Position Place at Torque or Bin Position Approach Knob Feeder Grip Knob at Feeder Pluck Knob from Feeder Intermediate Knob Placement Position Approach Knob Placement Position Place Knob in Position Figure 26. Robot Program Points 24

25 SCREW THREAD ENGAGEMENT MODULE (LAST PROCESS) POINT 9 POINT 17 SPOOL INSERTION MODULE (FIRST PROCESS) POINT 7 PARTS BIN KNOB FEEDER POINT 11 POINT 13 POINT 14 (KNOB IS CLEAR OF FEEDER) Figure 27. Robot Critical Point Locations 25

26 18. Place an acrylic block on the feed stand in the position toward the front of the station. 19. Teach the pickup points for the acrylic part as shown in figure 28. POINT 4 POINT 5 VALVE BODY FEED STAND Figure 28. Pick Up Points The function of each pickup point is described as follows: Point 4 is an approach point above the acrylic valve body Point 5 is a grip point for grasping the acrylic valve body This point must be taught with the valve body placed in the robot gripper. 20. Perform the following substeps to run the robot program using the teach pendant or proceed to Step 21 to run the program using the Robot Control software. A. From the Main Menu, press [F4] RUN to enter the Run menu. B. Press [F1] STR. The teach pendant display will list the default file, Controller 1. C. Press the [NEXT] key. The program mech will appear in the teach pendant display. D. Press [ENTER] to run the program. The robot will retrieve a knob/spring assembly from the feeder and place it in the assembly fixture, and then move to a wait position. 21. Click on the Run button shown in the File Control toolbar. 26

27 22. Perform the following substeps to move the station through its sequence of operations in the manual mode. 1. Robot Places Knob/Spring Assembly at the Screw Thread Engagement Module 2. Robot Places Valve Body at the Spool/Screw Insertion Module 3. Extend Clamp 1 4. Extend Spool Insertion Cylinder 5. Screw Feeder Queue On/Start First Time Delay for Screw Release 6. Retract Spool Insertion Cylinder/Screw Feeder Queue Off/Start Second Time Delay for Completion of Screw Insertion 7. Retract Clamp 1 8. Extend Transport Cylinder 9. Retract Transport Cylinder 10. Extend Clamp Extend Knob Cylinder/Start Bolt Motor 12. Knob Extended/Start Dwell Time Delay 13. Dwell Timer Times Out/Retract Knob Cylinder/Turn Motor Off 14. Retract Clamp Assembly Complete/Robot Pick Up Assembly and Place in Bin 16. Cycle Ends 27

28 In the manual mode, each momentary press of the start pushbutton causes the station s next sequence step to be performed. Observe the system and notify your instructor of anything that does not function properly or needs adjustment. A. Manually place a good acrylic valve body on the feed stand as shown in figure 29. Figure 29. Acrylic Valve Body on the Feed Stand B. Press the Start pushbutton momentarily to activate Steps 1 and 2 of the sequence. After receiving the input signal from the Start pushbutton, the robot will pick up a knob/spring assembly and place it on the assembly fixture and then move back to a wait position. The robot will then move to the acrylic part, pick it up, and place it in the spool insertion module. C. Press the Start pushbutton momentarily to activate Step 3 of the sequence. Pushing the Start pushbutton will cause the PLC to activate SOL2 and extend clamp cylinder 1 to hold the valve in place. D. Press the Start pushbutton momentarily to activate Step 4 of the sequence. The PLC will energize SOL1 to extend the spool insertion cylinder, which pushes the spool into the valve body. E. Press the Start pushbutton momentarily to activate Step 5 of the sequence. The PLC energizes SOL4, which activates the screw insertion module queue. The queue releases a screw and it feeds part way into the spool, but keeps it from going completely into the spool, as it would hit the spool insertion cylinder. 28

29 F. Press the Start pushbutton momentarily to activate Step 6 of the sequence. The PLC de-energizes SOL1 and the spool insertion cylinder is retracted. Once the retract limit switch is made, SOL4 is turned off allowing the screw insertion queue to release the screw. The next screw in line is actually pushing the screw into the spool. The queue cylinder prevents the next screw from extending into the assembly area. G. Press the Start pushbutton momentarily to activate Step 7 of the sequence. The PLC de-energizes SOL2 and clamp cylinder 1 retracts. H. Press the Start pushbutton momentarily to activate Step 8 of the sequence. SOL5 is energized and the transport cylinder extends, pushing the partial assembly on to the knob/spring assembly module. I. Press the Start pushbutton momentarily to activate Step 9 of the sequence. SOL5 is de-energized and the transport cylinder retracts. J. Press the Start pushbutton momentarily to activate Step 10 of the sequence. The PLC energizes SOL3, which causes clamp cylinder 2 extends to hold the valve body in place during the knob/spring assembly process. K. Press the Start pushbutton momentarily to activate Steps 11 and 12 of the sequence. SOL6 is energized and the knob assembly cylinder extends. The screw motor also turns on. The cylinder pushes the knob/spring assembly into the spool while the rotating motor shaft engages the screw head, turning it to thread screw into the knob. The motor will turn until the knob cylinder reaches the extend switch. This indicates that the knob threads have engaged on the screw. L. Press the Start pushbutton momentarily to activate Step 13 of the sequence. The PLC de-energizes SOL6 and the knob assembly cylinder retracts. The screw motor also turns off. M. Press the Start pushbutton momentarily to activate Step 14 of the sequence. Clamp cylinder 3 retracts indicating the end of the assembly process. 29

30 N. Press the Start pushbutton momentarily to activate Step 15 of the sequence. The PLC signals the robot that the valve is assembled. The robot then moves over to the assembly, picks it up, and drops it in the part bin. The robot will then get a new spring/knob assembly, place it in the assembly station, and move to a wait position. 23. Turn the Mode Selector switch to Auto. If you successfully single-stepped through the complete sequence and all of the actuators are back in their home position, the Start pushbutton lamp should be off at this time and you can move on to Step 25. If it is not, perform Step 24 to reset the actuators. 24. Perform the following substeps to home the station and set automatic mode. A. Remove the spring/knob assembly from the assembly station and place it back in the feeder, knob end down. B. Turn the Mode Selector switch to Reset. This will move all of the actuators back to their home positions. The robot will then get a new spring/knob assembly, place it in the assembly station, and move to a wait position. C. Turn the Mode Selector switch to Auto. 25. Manually place a good valve body in the recess provided on the Feed Stand. 26. Press the Start pushbutton to start the automatic cycle. Observe the station while it goes through one cycle. It is programmed to run through one cycle and then stop. The Start pushbutton indicator is on solid during the whole cycle to indicate the station is operating. 27. Perform the following substeps to test the operation of the station. A. Manually place a good acrylic valve body in the recess provided on the Feed Stand. B. Press the Start pushbutton to start the automatic cycle. C. During the middle of the cycle, press the Stop pushbutton to stop the system. The Stop pushbutton is programmed as a halt function, which means the station will complete its current sequence step and stop with all power remaining on. You should see the operation continue to the end of the current sequence step. 30

31 D. Observe the operator panel indicators and record their status in the table below. OPERATOR PANEL INDICATORS Indicator Status (On/Off/Blinking) Output Power Lamp Start Lamp Emergency Stop Lamp Figure 30. Operator Panel Indicators Since this is a halt, the machine can resume operation, so you should observe that Output power remains on and the start pushbutton should be off. It has been programmed to do so when the station is in the auto mode and ready to run its automatic cycle. The emergency stop lamp should be off because it is not pressed. E. Observe the PLC processor s status indicators and record their status. SF DC5V FRCE RUN STOP PLC PROCESSOR STATUS INDICATORS Indicator Status (On/Off) Figure 31. PLC Processor Status Indicators You should see that the PLC processor s DC5V and Run indicator lights are on, because the station is halted and ready to resume automatic operation. F. Observe the PLC I/O modules status indicators to see if any are on. You should see various input and output indicators on. Which ones depend on the point in the operation at which the Stop pushbutton was pushed. G. Press the Start pushbutton to restart the system. It should continue where it left off and finish the cycle. NOTE If any actuators are manually moved while the system is halted, the station may not resume operation when the start pushbutton is pressed. If this occurs, go to Step 29 and restart the system. 31

32 28. Repeat Step 26 three times, stopping the cycle with the Stop pushbutton at different times to observe how it reacts. 29. Perform the following substeps to restart the station IF any of the inputs changed after the Stop pushbutton is pressed. If any of the inputs were changed, like a part removed from the conveyor, or a cylinder moved physically, the system cannot be restarted with the Start pushbutton. This is because the input signals will no longer match those needed to begin the sequence. This is a protective measure to prevent damage to the system. A. Turn the Mode Selector switch to Reset. This will move all of the actuators back to their home positions. Once the actuators are reset, the Start pushbutton lamp should turn off. B. Manually place a good valve body in the recess provided on the Feed Stand. C. Turn the Mode Selector switch back to Auto. D. Press and release the Start pushbutton to start the automatic cycle. Observe the system while it goes through a cycle before continuing to the next step. 30. Perform the following substeps to record the operation of the station when the Emergency Stop pushbutton is pressed. This step will show you how the system is programmed to respond to the emergency stop pushbutton. A. Manually place a good valve body in the recess provided on the Feed Stand. B. Press and release the Start pushbutton. C. During the cycle, press the Emergency Stop pushbutton. Observe the operator panel indicators and record their status in the table below. OPERATOR PANEL INDICATORS Indicator Status (On/Off/Blinking) Output Power Lamp Start Lamp Emergency Stop Lamp Figure 32. Operator Panel Indicators Since this is an emergency stop, the machine cannot resume operations. You should observe that the output power is off, the Start pushbutton lamp is off, and the Emergency Stop lamp is on. You should also note that the robot stopped immediately after the e-stop was pressed, although it does not lose power. The robot s program is designed to end immediately when the emergency stop is pressed. The Emergency Stop function does not remove the air supply. 32

33 D. Observe the PLC processor s status indicators and record their status. SF DC5V FRCE RUN STOP PLC PROCESSOR STATUS INDICATORS Indicator Status (On/Off) Figure 33. PLC Processor Status Indicators You should see the PLC processor s DC5V and Run indicator lights on. E. Observe the PLC I/O modules status indicators to see if any are on. You should see various input indicators on, but all output indicators are off. This is because the Emergency stop circuit breaks power to the Output power contactor, which drops all output power. 31. Perform the following substeps to recover from the Emergency Stop. A. Remove any valve bodies or spring/knob assemblies that are on the station. B. Pull the Emergency Stop pushbutton out. C. Press the Output Power pushbutton to turn the outputs back on. You should hear the contactor pull in to re-establish the power to the outputs. You should also see the robot move to the spring/knob assembly feeder, pick an assembly from the feeder, and place it in the assembly fixture. Reset is not necessary at this point as all of the valves are spring return and will go back to their home position when they no longer have an output holding them. D. Place a good valve body into the recess on the Feed Stand. E. Turn the Mode Selector switch back to Auto. F. Press and release the Start pushbutton to start the automatic cycle. Observe the system while it goes through a cycle. G. Press the Stop pushbutton after the cycle completes. H. Manually place a good valve body in the recess provided on the Feed Stand after the cycle completes. 32. Perform the following substeps to record the operation of the station when it experiences a power loss. This will show you how the station is programmed to respond to a power loss. A. Press the Start pushbutton to start an automatic cycle. B. During the middle of the cycle turn the Main Power switch to Off to remove power to the system. 33

34 C. Observe the operator panel indicators and record their status in the table below. OPERATOR PANEL INDICATORS Indicator Status (On/Off/Blinking) Output Power Lamp Start Lamp Emergency Stop Lamp Figure 34. Operator Panel Indicators Because this is a power loss, simulated by turning the Main Power switch off, power to everything past the Main Power switch is turned off. You should see all operator panel indicator lamps and PLC indicators are off, but you will notice that the pneumatic power remains. You should also have noted that all of the cylinders return to their home position as there is no output power to keep the single-acting solenoids energized. You should also note that the robot stopped immediately after the Main Power switch was turned off, although it does not lose power. The robot s program is designed to end immediately when the station power is dropped. D. Observe the PLC processor s status indicators and record which indicators are on. SF DC5V FRCE RUN STOP PLC PROCESSOR STATUS INDICATORS Indicator Status (On/Off) Figure 35. PLC Processor Status Indicators You should see all indicators off because there is no power to the PLC. E. Observe the PLC I/O modules status indicators to see if any are on. Again, you should see all input and output indicators off because the modules have no power. 34

35 33. Perform the following substeps to recover from the power loss. A. Remove any valve bodies that are on the work surface. B. Place the Mode Selector switch in the Manual position. C. Turn the station s Main Power switch to the On position. D. Press the Output Power pushbutton to enable the PLC s outputs You should also hear the contactor located next to the PLC module pull in. The Start pushbutton lamp should be off because the station is ready for operation E. Turn the Mode Selector switch to Auto. F. Manually place a good valve body in the recess provided on the Feed Stand. G. Press the Start pushbutton to restart the operation. You should see the system start through its sequences. H. Run the system through two complete cycles to make sure it has recovered correctly. 34. Perform the following substeps to shutdown the robot controller and Robot Control software. A. Move the robot to the home position. B. Disable the Robot s drives. C. Close the Robot s Control software. D. Turn off the robot controller. 35. Perform the following substeps to power down the station. A. Turn the Main Power switch Off. B. Close the SIMATIC Manager. C. Turn off the PC and monitor. D. Perform a lockout/tagout on the system s electrical power source. E. Perform a lockout/tagout on the system s pneumatic power source. 35

36 SEGMENT 1 SELF REVIEW 1. Robots in assembly systems are used for assembly or for 2. In robotic assembly systems, the robots are often interfaced to to enable them to coordinate operations. 3. Servo robotic assembly systems use assembly, parts feeders, and a robot. 4. Pick and place assembly systems are typically controlled by a. 5. Pick and place assembly systems use that lift, move, and place objects in desired locations. 6. Gravity feeders hold for use in the process. 7. Automatic screw feeder cylinders are regulated using. 36

37 SEGMENT 2 COMPONENT ADJUSTMENT OBJECTIVE 5 DESCRIBE HOW TO ADJUST A PARTS FEEDER WITH ESCAPEMENT Some feeder escapements must be adjusted mechanically. One example is the parts chute escapement shown in figure 36. In this example, the escapement is a spring loaded ball, which holds the parts in the chute until an external force is applied to pull a part past the escapement. The spring force must be adjusted so that it holds the parts back but is not so high that a part cannot be pulled out of the chute. In many applications, a sensor is positioned to read when the feeder is out of parts, sending a signal to the PLC to stop the sequence until more parts are put in the chute. This sensor may also require physical adjustment so that it senses a part when present and it doesn t sense parts when the feeder is out. PART FEEDER PART PRESENT SENSOR ESCAPEMENT PART Figure 36. Mechanical Adjustments on a Parts Feeder 37

38 The availability of the part relies on the adjustment of the feeder to allow the part to feed properly. The part should move smoothly and quickly into place. If it does not, the feeder may require mechanical adjustments. This may include adjusting the size of the feeder, modifying the angle at which it is oriented, or some other physical adjustment. Part feeders often position the part for a part placement device, which makes the positioning of the part feeder critical. Mounting holes may be slotted or the bases may be adjustable using adjustment screws, both of which provide a method of properly aligning the feeder with the mating part or pickup device location. Parts Feeder with Escapement Adjustment To adjust a feeder, first test the part chute to verify that the parts drop smoothly and evenly. This may require manually actuating cylinders or manually removing parts from the part present location, if applicable. Make any adjustments to enable the parts to drop easily using the adjustment screw. Also verify that the part can be picked up from its current position. This also may require manually actuating cylinders or pickup devices. Make any necessary location adjustments using the chutes adjustment screws or mounting screws. For example, to adjust the friction ball escapement in figure 37, the retaining nut is loosened slightly. The escapement screw is then adjusted. Moving the friction ball in towards the part increases the friction, which increases the amount of force required to remove the part. Moving the friction ball out away from the part decreases the friction, which decreases the amount of force required to remove the part. Once the escapement is set to the desired position, the retaining nut is tightened preventing the escapement from moving. MOUNTING SCREWS ESCAPEMENT ADJUSTMENT SCREW MOUNTING BRACKETS ESCAPEMENT Figure 37. Adjust Part Chute 38

39 SKILL 2 ADJUST A PARTS FEEDER WITH ESCAPEMENT Procedure Overview In this procedure, you will adjust and test the parts feeder with escapement on the 87-MS5 Servo Robotic Assembly station. 1. Locate the 87-MS5 Servo Robotic Assembly station. 2. Verify that this station has been separated from any other stations. If it has not, then separate it from the other stations. If it has, then proceed to Step Perform the following safety check before you begin working on the station. Make sure that you can answer yes to each item before proceeding. YES/NO Figure 38. SAFETY CHECKOUT Remove all obstructions from the work area Check for signs of damage to the equipment Wear tight fi tting clothing, roll up long sleeves, remove ties, scarves, jewelry, etc. Tie up long hair Remove any robot teach pendants from the work area Locate the emergency stop button Ensure that safety glasses are worn by people in the area Ensure that all people are outside any work envelopes Mechatronics Safety Check 39

40 4. Locate the knob/spring assembly gravity feeder, shown in figure 39. Figure 39. Knob/Spring Assembly Feeder 5. Perform the following substeps to adjust the escapement on the part feeder. A. Remove all of the knob/spring assemblies from the feeder. B. Locate the escapement/stop and its adjustment screw, shown in figure 40. ADJUSTMENT SCREW NUT ESCAPEMENT Figure 40. Escapement and Adjustment Screw 40

41 C. Loosen the nut on the adjustment screw by turning it 2 turns CCW. This should be just finger tight, but if a wrench is required, use a 3/8 in. open-end wrench to loosen it. You can obtain this from your instructor. D. Back the adjustment screw out 1 turn by turning it CCW. This will remove the escapement so that it will no longer stop parts from falling out. E. Place a knob/spring assembly, knob side down, into the top of the part feeder and let go. The knob/spring assembly should fall straight through the feeder. F. Tighten the escapement adjustment screw 1 turn CW. G. Drop another knob/spring assembly into the feeder. This time, the escapement should stop the part from falling out of the feeder. H. Tighten the nut on the adjustment screw by turning it CW 2 turns. I. Replace the knob/spring assemblies in the feeder. 6. Perform the following substeps to adjust the location of the part feeder on its support post. A. Obtain from your instructor a 4 mm hex wrench. B. Use a pencil to mark the position of the knob/spring feeder support bracket, as shown in figure 41. MARK LOCATION Figure 41. Feeder Support Bracket Location 41

42 C. Using the hex wrench, loosen the two bolts on the bracket, shown in figure 38, 1 turn each. This should make the bracket loose enough to move without unthreading the bolts from their T-nuts. D. Move the bracket up and down in the slotted extrusion and note how easily the location can be modified. Keep in mind that if this location is modified, at least 4 robot teach points would have to be taught over again. E. Move the bracket back to the location you previously marked. F. Tighten the nuts with the hex wrench. G. Return the wrench(es) to your instructor. 42

43 OBJECTIVE 6 DESCRIBE HOW TO ADJUST AN AUTOMATIC SCREW FEEDER Automatic screw feeders, such as the one shown in figure 42, use flow control valves to control the speed at which the screw is released into the process. Adjustments are made to either accelerate or decelerate the speed of the cylinders and thus the release of the screw. REMOVABLE CAP TO ADD SCREWS TO QUEUE S SCREW INSERTION MODULE SCREW PATH DIAL INDICATOR AIR REGULATOR TUBING HOLDS SCREWS IN QUEUE INDUCTIVE PART PRESENT SENSOR Figure 42. Automatic Screw Feeder The following procedures are recommended for adjusting this type of automatic screw feeder. 43

44 Step 1: Adjust the flow controls for the screw stop cylinder (works independently) - By adjusting the flow controls on this cylinder, the speed at which the screw is fed into the system and the next screw is trapped are modified. Turning the adjustment CW reduces the speed by restricting the air flow, while turning it CCW increases the flow and the speed at which the cylinder retracts. When making adjustments to the flow control, make sure the cylinder retracts and extends at a speed that allows the part to be trapped and released at the correct times while not slowing the production process. 3 FLOW CONTROL VALVE Figure 43. Flow Control on Independent Cylinder 44

45 Step 2: Adjust the flow controls for the cylinders working together - These cylinders trap the head of the screw being inserted until the process is ready for it. Turning the adjustment CW reduces the speed by restricting the exhaust air flow, while turning it CCW increases the flow and so the speed at which the cylinder retracts. This will change the speed the screw is released from the screw guide. SCREW GUIDES FLOW CONTROL VALVE 1 FLOW CONTROL VALVE SCREW 2 Figure 44. Flow Controls on Cylinder Pair 45

46 SKILL 3 ADJUST AN AUTOMATIC SCREW FEEDER Procedure Overview In this procedure, you will adjust and test an automatic screw feeder. This will familiarize you with the operation and adjustment of an automatic screw feeder system. 1. Locate the 87-MS5 Servo Robotic Assembly station. 2. Verify that this station has been separated from any other stations. If it has not, then separate it from the other stations. If it has, then proceed to Step Perform the following safety check before you begin working on the station. Make sure that you can answer yes to each item before proceeding. YES/NO SAFETY CHECKOUT Remove all obstructions from the work area Check for signs of damage to the equipment Wear tight fi tting clothing, roll up long sleeves, remove ties, scarves, jewelry, etc. Tie up long hair Remove any robot teach pendants from the work area Locate the emergency stop button Ensure that safety glasses are worn by people in the area Ensure that all people are outside any work envelopes Figure 45. Mechatronics Safety Check 4. Verify that the Feed Stand is installed on the station. If it is not, install it. The feed stand is used when the 87-MS5 is separated from the other station to enable the robot to pick up the valve bodies. 5. Verify the parts bin is installed on the station. If it is not, install it. The parts bin is used when the station is separated from the other stations to catch the parts as the robot drops them. 6. Connect an air supply to the station s air manifold quick connect. 7. Perform the following substeps to power up the 87-MS5 Servo Robotic Assembly station. A. Remove the lockout/tagout device from the pneumatic power source. 46

47 B. Turn on air to the station by shifting the lever on the pneumatic lockout valve. C. Set the station s air supply regulator to 50 psi/345 kpa. D. Set the screw feeder s air supply regulator to 12 psi/82.7 kpa. 8. Perform the following substeps to adjust the extend and retract flow controls on the screw feeder cylinders. FLOW CONTROL VALVE 3 FLOW CONTROL VALVE 1 3 Figure 46. Screw Feeder Cylinders A. Use the cylinder s manual override to extend and retract the cylinders and notice how quickly it does each movement. Extend (slow/fast) Retract (slow/fast) B. Rotate the extend flow control valve three turns CW. C. Rotate the retract flow control valve three turns CCW. D. Use the cylinder s manual override to extend and retract the cylinder and note how each movement was affected by the adjustment. Extend Retract You should have seen the valve extend more slowly and retract more quickly. E. Rotate the extend flow control three turns CCW to position it to the original setting. 47

48 F. Rotate the retract flow control three turns CW to position it to the original setting. G. Use the cylinder s manual override to verify that the cylinder s settings are back to their original positions. 9. Perform a lockout/tagout on the system s pneumatic power source. OBJECTIVE 7 DESCRIBE HOW TO ADJUST A PNEUMATIC PART SHUTTLE A pneumatic part shuttle, such as the one shown in figure 47, uses a rodless cylinder with an attached arm or tab to shuttle the parts from one location to the next. In the example shown in figure 48, the arm is bolted to the carriage. This arm will extend through a slot in the work surface above it to slide the part from one process to the next. The cylinder also has two meter in flow control valves that are used to adjust the speed of the cylinder in either direction. MOUNTING BLOCK FLOW CONTROL RODLESS SHUTTLE ARM CARRIAGE FLOW CONTROL MOUNTING BLOCK Figure 47. Rodless Cylinder 48

49 SHUTTLE ARM EXTENDS THROUGH WORK SURFACE FLOW CONTROL FOR EXTEND FINAL PART LOCATION AT PROCESS 2 SHUTTLE ARM ON CARRIAGE ORIGINAL PART LOCATION AT PROCESS 1 FLOW CONTROL FOR RETRACT Figure 48. Part Shuttle Application Adjusting a part shuttle such as the one in the example involves adjusting the flow control valves on the cylinder. Turning the flow control CCW will decrease the speed, while turning it CW will increase the speed. If the flow control adjustment includes a locking nut to prevent vibration from changing the setting, make sure the nut is loosened before changing the setting and tighten it after the new setting is made. 49

50 SKILL 4 ADJUST A PNEUMATIC PART SHUTTLE Procedure Overview In this procedure, you will adjust and test a pneumatic part shuttle. This will familiarize you with the operation and adjustment of a pneumatic part shuttle system. 1. Locate the 87-MS5 Servo Robotic Assembly station. 2. Verify that this station has been separated from any other stations. If it has not, then separate it from the other stations. If it has, then proceed to Step Perform the following safety check before you begin working on the station. Make sure that you can answer yes to each item before proceeding. YES/NO SAFETY CHECKOUT Remove all obstructions from the work area Check for signs of damage to the equipment Wear tight fi tting clothing, roll up long sleeves, remove ties, scarves, jewelry, etc. Tie up long hair Remove any robot teach pendants from the work area Locate the emergency stop button Ensure that safety glasses are worn by people in the area Ensure that all people are outside any work envelopes Figure 49. Mechatronics Safety Check 4. Connect an air supply to the station s air manifold quick connect. 5. Perform the following substeps to power up the 87-MS5 Servo Robotic Assembly station. A. Remove the lockout/tagout device from the pneumatic power source. B. Turn on air to the station by shifting the lever on the pneumatic lockout valve. C. Set the station s air supply regulator to 50 psi/345 kpa. D. Set the screw feeder s air supply regulator to 12 psi/82.7 kpa. 50

51 6. Perform the following substeps to adjust the extend and retract flow controls on the pneumatic part shuttle cylinder. PART SHUTTLE FLOW CONTROL Figure 50. Part Shuttle Cylinder A. Use the cylinder s manual override to extend and retract the cylinders and notice how quickly it does each movement. Extend (slow/fast) Retract (slow/fast) B. Rotate the extend flow control valve three turns CCW. C. Rotate the retract flow control valve three turns CW. D. Use the cylinder s manual override to extend and retract the cylinder and note how each movement was affected by the adjustment. Extend Retract You should have seen the valve extend more slowly and retract more quickly. E. Rotate the extend flow control three turns CW to position it to the original setting. F. Rotate the retract flow control three turns CCW to position it to the original setting. G. Use the cylinder s manual override to verify that the cylinder s settings are back to their original positions. 7. Perform a lockout/tagout on the system s pneumatic power source. 51

52 SEGMENT 2 SELF REVIEW 1. A parts feeder with an escapement usually includes a to indicate when there are no parts left. 2. If the part does not feed properly adjustments to the feeder may be required. 3. A part chute should be adjusted to allow the parts to drop. 4. Pneumatic cylinders have to control the speed they extend and retract. 5. By regulating the speed at which the extend and retract, the speed at which the part is released and fed into the part can be controlled. 6. A rodless cylinder used as a part shuttle uses to control extend and retract speed. 52

53 SEGMENT 3 MODULE SEQUENCING OBJECTIVE 8 DESCRIBE A SEQUENCE OF OPERATION OF A PART INSERTION MODULE A typical part insertion module uses pick and place components to assemble parts by placing one part into another part. One example is shown in figure 51, which shows a module that inserts a spool into a valve body. This example uses a double-acting cylinder to push a spool from a feeder into the valve body. The cylinder has magnetic reed switches mounted to it that indicate to the PLC when it has completed its stroke. The part insertion module also includes a clamping cylinder to hold the part stationary while work is being performed on it. The spool feeder portion of the module is equipped with an inductive sensor to detect when parts are present. VALVE SPOOLS CLAMPING FEEDER MR3 MAGNETIC REED SWITCHES MR2 MR1 SINGLE SOLENOID DCV (SOL2) DOUBLE-ACTING SINGLE SOLENOID DCV (SOL1) PART PRESENT SENSOR (INDUCTIVE) FIXTURE VALVE BODY Figure 51. Part Insertion Module Construction 53

54 The part insertion module is generally controlled by a PLC, but could also be controlled by robotic I/O. In either case, the sequence will be similar to that shown in the following table. PART INSERTION MODULE SEQUENCE STEP INPUT OUTPUT 1 Receive Start input (S1 on) Extend Clamp 1 (SOL2 on) 2 Clamp 1 Extended (MR3 on) Extend Part Insertion Cylinder (SOL1 on) 3 Part Insertion Cylinder Extended Retract Part Insertion Cylinder (MR1 on) 4 Part Insertion Cylinder Retracted Retract Clamp 1 (MR2 on) 5 Clamp 1 Retracted Cycle Ends Figure 52. Part Insertion Module Sequence of Operation 54

55 Initial Condition The part insertion module must be in some pre-determined state before any sequence may take place. Many times this will be a state in which both the clamp 1 cylinder and the insertion cylinder are retracted (MR2 actuated). Typically, there is an interlock, indicating that motion at the source and/or destination station has stopped and it is now safe to transfer. One example would be that the source station s transfer table has stopped moving. If these initial conditions are not satisfied, the part insertion module will not operate and the PLC controlling the module may even provide an alarm light or message to the operator, indicating that operator intervention is necessary. MR2 ON INSERTION RETRACTED CLAMP 1 RETRACTED PART INSERTION FROM SOURCE SOL1 RETRACTED MR2 PART INSERTION MR1 SOL2 CLAMP #1 MR3 Figure 53. Initial Condition 55

56 Step 1: Receive Start Input, Extend Clamp 1 Cylinder In this step, the PLC controlling the part insertion module receives an input to start the sequence. The input may be from another workstation, an operator, or the robot tending the module. After receiving the input signal, the PLC energizes SOL2 to extend Clamp 1 cylinder and clamp the part in place. This holds the part steady while assembly operations are being performed. CLAMP 1 BEGINS TO EXTEND FROM SOURCE SOL1 RETRACTED MR2 PART INSERTION MR1 SOL2 CLAMP #1 MR3 Figure 54. Step 1: Receive Start Input, Extend Clamp 1 Cylinder 56

57 Step 2: Clamp 1 Cylinder Extended, Extend Part Insertion Cylinder Once the clamp cylinder s magnetic reed switch (MR3) indicates that the cylinder is extended, the PLC energizes SOL1 to extend the part insertion cylinder. This will push the part from the part feeder and into the waiting assembly. PART INSERTION BEGINS TO EXTEND MR3 ON CLAMP 1 FROM SOURCE SOL1 RETRACTED MR2 PART INSERTION MR1 SOL2 CLAMP #1 MR3 Figure 55. Step 2: Clamp 1 Cylinder Extended, Extend Part Insertion Cylinder 57

58 Step 3: Part Insertion Cylinder Extended, Retract Part Insertion Cylinder The extension of the part insertion cylinder is indicated by its magnetic reed switch (MR1), which causes the PLC to de-energize SOL1. This will allow the part insertion cylinder to retract. PART INSERTION PART IN ASSEMBLY MR2 OFF MR1 ON FROM SOURCE SOL1 RETRACTED MR2 PART INSERTION MR1 SOL2 CLAMP #1 MR3 Figure 56. Step 3: Part Insertion Cylinder Extended, Retract Part Insertion Cylinder 58

59 Step 4: Part Insertion Cylinder Retracted, Retract Clamp 1 Cylinder When the part insertion cylinder is retracted, it turns on switch MR2. This causes SOL2 to turn off and retract the clamp 1 cylinder. A time delay is started to give the cylinder time to retract. RETRACTED MR2 ON MR1 OFF FROM SOURCE SOL1 RETRACTED MR2 PART INSERTION MR1 SOL2 CLAMP #1 MR3 Figure 57. Step 4: Part Insertion Cylinder Retracted, Retract Clamp 1 Cylinder 59

60 Step 5: Clamp 1 Retracted, Cycle Ends Once the time delay ends, the clamp 1 cylinder is retracted. This loosens the part and allows it to be removed for further processing. The cycle then stops until it receives the start input again. CLAMP RETRACTED FROM SOURCE SOL1 RETRACTED MR2 PART INSERTION MR1 SOL2 CLAMP #1 MR3 Figure 58. Step 5: Clamp 1 Retracted, Cycle Ends 60

61 59. The sequence just described is summarized by the sequence diagram in figure PART INSERTION MODULE SEQUENCE OF OPERATIONS INPUTS OUTPUTS Step Input Action Output Action Start PB Stop PB MR1 MR2 MR3 SOL1 SOL2 0 Start Condition Receive Start Input Extend Clamp Cylinder 1 1/0 1 2 Clamp 1 Cylinder Extended Extend Part Insertion Cylinder Part Insertion Cylinder Extended Retract Part Insertion Cylinder Part Insertion Cylinder Retracted Retract Clamp Clamp 1 Cylinder Retracted Cycle Ends 0 End Condition Figure 59. Sequence Diagram 61

62 SKILL 5 DESIGN A PLC PROGRAM THAT SEQUENCES A PART INSERTION MODULE Procedure Overview In this procedure, design a PLC project to control a part insertion module given the following information. 1. Design a PLC project to control a part insertion module given the following information. The general sequence, I/O diagram, power diagrams as follows: General Sequence 1) Pressing the Start pushbutton causes the Clamp 1 cylinder to extend. 2) After the Clamp 1 cylinder is extended, indicated by MR3, the spool insertion cylinder is extended 3) After the spool insertion cylinder is extended (MR1 on), it is retracted. 4) After the spool insertion cylinder is retracted (MR2 on), the clamp cylinder is retracted. 5) After the clamp cylinder is retracted (1 second time delay), then the cycle ends. Special Conditions The start pushbutton lamp will be off when the station is in its home position and on solid when it is running. The transport cylinder (SOL5), clamp 1 cylinder (SOL2), and the spool insertion module (SOL1) should be manually positioned at the home position using the manual overrides. A valve body should be manually placed in the recess on the work surface. 62

63 Pressing the Stop pushbutton at any time should cause the sequence to stop (or halt) at the end of its current step. Pressing the Start pushbutton should resume the sequence. The cycle should repeat when a new part is placed onto the work surface and the Start pushbutton is pressed. INPUTS I/O DIAGRAM OUTPUTS PB START INPUT I0.0 SPOOL INSERTION EXTEND (SOL1) MR1 SPOOL INSERTION I1.2 Q4.5 CLAMP 1 EXTEND (SOL2) MR2 SPOOL INSERTION RETRACTED I1.3 Q4.6 MR3 CLAMP 1 I1.4 Figure 60. I/O Diagram FROM SOURCE SOL1 SPOOL INSERTION RETRACTED MR2 MR1 SOL2 CLAMP 1 MR3 Figure 61. Power Diagram 63

64 PART INSERTION MODULE SEQUENCE OF OPERATIONS INPUTS OUTPUTS Step Input Action Output Action 0 Start Condition Receive Start Input Extend Clamp Cylinder 1 1/0 1 2 Clamp 1 Cylinder Extended Extend Part Insertion Cylinder Part Insertion Cylinder Extended Retract Part Insertion Cylinder Part Insertion Cylinder Retracted Retract Clamp Clamp 1 Cylinder Retracted Cycle Ends 0 End Condition Figure 62. Sequence Diagram Start PB (I0.0) 2. Perform the following substeps to open the PLC programming software. A. Make sure that the interface from the personal computer to the PLC is connected. B. Power up the PC and monitor. C. Start the SIMATIC Manager. 3. Perform the following substeps to create a project. A. Create a Project named L7S4XXX where XXX represents your initials. B. Create an S7 Station object for the station and configure its hardware. C. Open Organizational Block OB1. D. Enter the program that you developed in Step 1 into Organizational Block OB1. E. Save OB1. 4. Locate the 87-MS5 Servo Robotic Assembly station. 5. If the 87-MS5 Servo Robotic Assembly station is connected to another 87- MS station, separate the stations. If the 87-MS5 Servo Robotic Assembly station is already disconnected, continue to Step 6. Stop PB (I0.1) MR1 (i1.2) MR2 (i1.3) MR3 (i1.4) SOL1 (Q4.5) SOL2 (Q4.6) 64

65 6. Perform the following safety check before you begin working on the station. Make sure that you can answer yes to each item before proceeding. YES/NO SAFETY CHECKOUT Remove all obstructions from the work area Check for signs of damage to the equipment Wear tight fi tting clothing, roll up long sleeves, remove ties, scarves, jewelry, etc. Tie up long hair Remove any robot teach pendants from the work area Locate the emergency stop button Ensure that safety glasses are worn by people in the area Ensure that all people are outside any work envelopes Figure 63. Mechatronics Safety Check 7. Connect an air supply line to the station s air manifold quick connect. 8. Plug the station s power cable into a wall outlet. 9. Perform the following substeps to power up the 87-MS5 Servo Robotic Assembly station. A. Place the Mode Selector switch in the Manual position. B. Remove the lockout/tagout device from the electric power source. C. Remove the lockout/tagout device from the pneumatic power source. D. Turn on the air to the station by shifting the lever on the lockout valve. E. Set the station s air supply regulator to 50 psi/345 kpa. F. Turn the station s Main Power Switch to the On position. 10. Perform the following substeps to download the project to the PLC. A. Reset the PLC. B. Download the SIMATIC 300 Station object to the PLC. Several dialogs will appear during the download. Click the appropriate response to continue downloading the program. The last dialog should ask if you wish to perform a complete (Warm) restart. C. Click Yes on the dialog to complete a warm restart. 11. Go online with the processor and monitor the OB1 Block. 12. Press the Output Power pushbutton to enable the PLC s outputs. 65

66 13. Perform the following substeps to test the operation of the program. A. Verify that there are spools inserted into the part feeder. If there are none, obtain some from your instructor. B. Place a good valve body in the recess provided in the orientation shown in figure 64. Figure 64. Valve Body Orientation C. Press and release the Start pushbutton. The following sequence should occur: The clamp 1 cylinder should extend. After the clamp 1 cylinder has extended, the spool insertion cylinder should extend, pushing a spool into the valve body. After the spool insertion cylinder has extended, it should retract. After the spool insertion cylinder has retracted, the clamp 1 cylinder should retract. This successfully completes one cycle of the part insertion module. D. Manually place a good valve body in the recess provided on the work surface. E. Press and release the Start pushbutton. The cycle should repeat. F. Repeat substeps D through F until you are familiar with the operation of the part insertion module. 14. Print out a copy of the ladder logic program and place it in your portfolio. It will be used in your assessment. 66

67 15. Click the Monitor button to go offline from the processor. 16. Use the PLC programming software to place the PLC into Stop mode. 17. Perform the following substeps to shut down the 87-MS5. A. Close the LAD/STL/FBD Editor. B. Close the SIMATIC Manager. C. Turn off the PC and monitor. D. Turn the 87-MS5 s Main Power switch to Off. E. Perform a lockout/tagout on the system s electrical power source. F. Perform a lockout/tagout on the system s pneumatic power source. 67

68 OBJECTIVE 9 DESCRIBE A SEQUENCE OF OPERATION OF A SCREW FEED MODULE An example of a screw feed module is shown in figure 65. This example includes a single-solenoid directional control valve and three double-acting cylinders that are used to control the screws as they are fed into the part. The module is equipped with an inductive sensor to detect when there are screws present in the queue. When the PLC receives a request for a screw and the part present sensor is on, the three cylinders start shifting to release the screw. One cylinder, which holds the screw back by restraining the screw head, begins to extend while the other two cylinders open a screw guide that keeps the screw straight and prevents screws from extending into the assembly area. When the system is ready, one cylinder retracts to let the next screw move into the screw guide which is now closed. The screw behind the one being inserted pushes the screw the rest of the way into the part. SOL2 SCREW FEED MODULE CLAMP (MR3) CLAMP VALVE/SPOOL ASSEMBLY SCREWS FIXTURE PART PRESENT SENSOR (IND3) SOL4 SINGLE - SOLENOID DIRECTIONAL CONTROL VALVE Figure 65. Screw Feed Module Construction 68

69 A screw feed module s sequence will be similar to that shown in the following table. SCREW FEED MODULE SEQUENCE OF EVENTS STEP INPUT OUTPUT 1 Receive Start input (S1 on) Extend Clamp 1 Cylinder (SOL2 on) 2 Clamp 1 Cylinder Extended/ Screws Present (MR3, IND3 on) 3 Time Delay Ends/Screw Feed (Timer 1 done) Cylinders Return to Home Position 4 Second Time Delay Ends/Screw Completely Inserted into Valve Body (Timer 2 done) 5 Clamp 1 Retracted Cycle Ends Figure 66. Screw Feed Module Sequence of Operation Screw Feed Queue On/Start Time Delay (SOL4 on, Screw Insert Timer 1 Starts) Screw Feed Queue Off/Second Time Delay Starts (Screw Insert Timer 2 Starts) Retract Clamp 1 Cylinder 69

70 Initial Condition The screw feed module must be in some pre-determined state before any sequence may take place. In this example, the clamp cylinder is retracted, part present sensor IND3 is on, and the screw insertion queue cylinders are in their proper positions. If these initial conditions are not satisfied, the screw feed module will not operate and an alarm light or message to the operator may be activated. 3 RETRACTED CLAMP 1 RETRACTED IND3 ON 1 RETRACTED 2 TOP VIEW OF S FROM SOURCE SOL2 SCREW RESTRAINT 3 CLAMP 1 SCREW GUIDE 1 SCREW GUIDE 2 MR3 PNEUMATIC SCREW FEEDER TUBE SOL4 SCREW INSERTION QUEUE S SCREW GUIDE QUEUE 1 SCREW GUIDE QUEUE 2 SCREW RESTRAINT QUEUE 3 Figure 67. Initial Condition 70

71 Step 1: Receive Start Input, Extend Clamp 1 Cylinder In this step, the PLC controlling the screw feed module receives an input to start the sequence. The input may be from another workstation, an input detecting that a part is present and ready for assembly, or it may be from an operator. After receiving the input signal, the PLC energizes SOL2 and the clamp cylinder extends. CLAMP 1 BEGINS TO EXTEND TOP VIEW OF S SCREW RESTRAINT 3 SCREW GUIDE 1 FROM SOURCE SOL2 CLAMP 1 SCREW GUIDE 2 MR3 PNEUMATIC SCREW FEEDER TUBE SOL4 SCREW INSERTION QUEUE S SCREW GUIDE QUEUE 1 SCREW GUIDE QUEUE 2 SCREW RESTRAINT QUEUE 3 Figure 68. Step 1: Input Signal Received, Extend Clamp 1 Cylinder 71

72 Step 2: Clamp 1 Cylinder Extended/Part Present Sensor On, Screw Insertion Queue On/Start Time Delay Once the clamp is extended, activating MR3, the PLC looks at the screw part presence sensor (IND3). If IND3 detects a part the sequence will continue, if it does not then the sequence will be halted. When the PLC receives the signal that a part is present, it activates SOL4, which controls the screw insertion queue cylinders. Because there are no sensors on the screw insertion cylinders, a time delay is started to allow the cylinders time to perform their operation. During this step, the screw begins to exit the module and enters the part. 1 BEGINS TO EXTEND 3 BEGINS TO EXTEND MR3 ON CLAMP 1 2 BEGINS TO RETRACT TOP VIEW OF S SCREW RESTRAINT 3 BEGINS TO EXTEND SCREW GUIDE 1 BEGINS TO EXTEND FROM SOURCE SOL2 CLAMP 1 SCREW GUIDE 2 BEGINS TO RETRACT MR3 PNEUMATIC SCREW FEEDER TUBE SOL4 SCREW INSERTION QUEUE S SCREW GUIDE QUEUE 1 SCREW GUIDE QUEUE 2 SCREW RESTRAINT QUEUE 3 Figure 69. Step 2: Clamp 1 Extended/Part Present Sensor On, Screw Insertion Queue On/Start Time Delay 72

73 Step 3: Time Delay Ends, Screw Insertion Queue Off/Second Time Delay Starts When the timer times out, the PLC de-energizes SOL4, which causes the screw feed cylinders to return to their normal positions. This enables the screw behind the one being inserted into the part to push the one in front completely into the part. A second time delay is started to allow the process to complete. 3 BEGINS TO RETRACT 1 BEGINS TO RETRACT 2 BEGINS TO EXTEND TOP VIEW OF S FROM SOURCE SOL2 SCREW RESTRAINT 3 BEGINS TO RETRACT CLAMP 1 SCREW GUIDE 1 BEGINS TO RETRACT SCREW GUIDE 2 BEGINS TO EXTEND MR3 PNEUMATIC SCREW FEEDER TUBE SOL4 SCREW INSERTION QUEUE S SCREW GUIDE QUEUE 1 SCREW GUIDE QUEUE 2 SCREW RESTRAINT QUEUE 3 Figure 70. Step 3: Time Delay Ends, Screw Insertion Queue Off/Second Time Delay Starts 73

74 Step 4: Second Time Delay Ends, Retract Clamp Cylinder 1 Once the second time delay times out, the PLC de-energizes SOL2 and clamp cylinder 1 retracts. A short time delay will begin to allow the clamp cylinder time to retract. 3 RETRACTED CLAMP 1 BEGINS TO RETRACT 1 RETRACTED 2 TOP VIEW OF S FROM SOURCE SOL2 SCREW RESTRAINT 3 RETRACTED CLAMP 1 SCREW GUIDE 1 RETRACTED SCREW GUIDE 2 MR3 PNEUMATIC SCREW FEEDER TUBE SOL4 SCREW INSERTION QUEUE S SCREW GUIDE QUEUE 1 SCREW GUIDE QUEUE 2 SCREW RESTRAINT QUEUE 3 Figure 71. Step 4: Second time Delay Ends, Retract Clamp Cylinder 1 74

75 Step 5: Clamp 1 Retracted, Cycle Ends When the time delay for the clamp cylinder ends, clamp 1 will be retracted and the cycle ends. The cycle will repeat when the part is removed, a new part put in place, and the start input is received again. CLAMP 1 RETRACTED TOP VIEW OF S FROM SOURCE SCREW RESTRAINT 3 SCREW GUIDE 1 SCREW GUIDE 2 SOL2 CLAMP 1 MR3 PNEUMATIC SCREW FEEDER TUBE SOL4 SCREW INSERTION QUEUE S SCREW GUIDE QUEUE 1 SCREW GUIDE QUEUE 2 SCREW RESTRAINT QUEUE 3 Figure 72. Step 5: Clamp 1 Retracted, Cycle Ends 75

76 The sequence just described is summarized by sequence diagram in figure 73. SCREW FEED MODULE SEQUENCE OF OPERATION INPUTS OUTPUTS Step Input Action Output Action 0 Start Condition Receive Start Input Extend Clamp Cylinder 1 1/0 1 2 Clamp 1 Cylinder Extended/ Screws present in queue Screw Insertion Queue on/start fi rst time delay 3 First time delay ends Screw Insertion Queue off/start second time delay Second time delay ends Retract Clamp Cylinder Clamp 1 Cylinder Retracted 0 End Condition Figure 73. Sequence Diagram Start PB Stop PB MR3 IND3 SOL2 SOL4 T1 T2 76

77 SKILL 6 DESIGN A PLC PROGRAM THAT SEQUENCES A SCREW FEED MODULE Procedure Overview In this procedure, you will design and test a PLC program that sequences a screw feed module to insert screws into the valve bodies on the 87-MS5 Servo Robotic Assembly station. 1. Design a PLC program given the following information. The general sequence, I/O diagram, and power diagram are as follows: General Sequence: 1) Pressing the Start pushbutton (PB1) enables the PLC program, energizes the clamp 1 solenoid (SOL2) to extend the cylinder. 2) Once the cylinder is extended (MR3), the PLC looks at IND3 to verify there are screws present in the queue. 3) If IND3 is high, meaning there are screws present, then the PLC turns on SOL4 to activate the screw insertion queue. A timer starts (1 second) to give the queue cylinders time to perform the first part of the insertion. 4) After the time delay ends, SOL4 is turned off and a second time delay (1 second) starts to allow the screw insertion to complete. 5) When the second time delay ends, the cycle ends. It will start again once the Start pushbutton is pressed. Special Conditions: Pressing the Stop pushbutton at any time will cause the cylinder to stop (or halt) at the end of its current step. Pressing the Start pushbutton will resume the sequence. The Start pushbutton lamp will turn off when ready (motor ready signal on) and turn solid as the station is operating. 77

78 INPUTS I/O DIAGRAM OUTPUTS PB MR3 IND3 START INPUT I0.0 CLAMP 1 I1.4 SCREW PRESENT I2.6 Q4.6 CLAMP 1 EXTEND (SOL2) SCREW INSERTION QUEUE (SOL4) Q5.0 Figure 74. I/O Diagram FROM SOURCE SOL2 CLAMP 1 MR3 PNEUMATIC SCREW FEEDER TUBE SOL4 SCREW INSERTION QUEUE S QUEUE 1 QUEUE 2 QUEUE 3 Figure 75. Power Diagram 78

79 SCREW FEED MODULE SEQUENCE OF OPERATION INPUTS OUTPUTS Step Input Action Output Action 0 Start Condition Receive Start Input Extend Clamp Cylinder 1 1/0 1 2 Clamp 1 Cylinder Extended/ Screws present in queue Screw Insertion Queue on/start fi rst time delay 3 First time delay ends Screw Insertion Queue off/start second time delay Second time delay ends Retract Clamp Cylinder Clamp 1 Cylinder Retracted 0 End Condition Figure 76. Sequence Diagram Start PB (I0.0) 2. Perform the following substeps to open the PLC programming software. A. Make sure that the interface from the personal computer to the PLC is connected. B. Power up the PC and monitor. C. Start the SIMATIC Manager. 3. Perform the following substeps to create a project. A. Create a Project named L7S5XXX where XXX represents your initials. B. Create an S7 Station object for the station and configure its hardware. C. Open Organizational Block OB1. D. Enter the program that you developed in Step 1 into Organizational Block OB1. E. Save OB1. 4. If the 87-MS5 Servo Robotic Assembly station is connected to another station, separate the stations. If the 87-MS5 Servo Robotic Assembly station is already disconnected, continue to Step 5. Stop PB (I0.1) MR3 (I1.4) IND3 (2.6) SOL2 (Q4.6) SOL4 (Q5.0) T1 T2 79

80 5. Perform the following safety check before you begin working on the station. Make sure that you can answer yes to each item before proceeding. YES/NO SAFETY CHECKOUT Remove all obstructions from the work area Check for signs of damage to the equipment Wear tight fi tting clothing, roll up long sleeves, remove ties, scarves, jewelry, etc. Tie up long hair Remove any robot teach pendants from the work area Locate the emergency stop button Ensure that safety glasses are worn by people in the area Ensure that all people are outside any work envelopes Figure 77. Mechatronics Safety Check 6. Connect an air supply line to the station s air manifold quick connect. 7. Plug the station s power cable into a power outlet. 8. Perform the following substeps to power up the 87-MS5 Servo Robotic Assembly station. A. Remove the lockout/tagout device from the electric power source. B. Remove the lockout/tagout device from the pneumatic power source. C. Turn on the air to the station by shifting the lever on the lockout valve. D. Set the station s air supply regulator to 50 psi/ 345 kpa. E. Set the screw feed module s air supply regulator to 12 psi/82.7 kpa. F. Turn the station s Main Power Switch to the On position. 80

81 9. Perform the following substeps to download the project to the PLC. A. Reset the PLC. B. Download the SIMATIC 300 Station object to the PLC. Several dialogs will appear during the download. Click the appropriate response to continue downloading the program. The last dialog should ask if you wish to perform a complete (Warm) restart. C. Click Yes on the dialog to complete a warm restart. 10. Go online with the processor and monitor the OB1 Block. 11. Manually place a spool into a valve body. 12. Manually place the valve body on the work surface in front of the screw feed module, as shown in figure 78. VALVE BODY Figure 78. Valve Body Replacement 13. Press the Output Power pushbutton to enable the PLC s outputs. 14. Perform the following substeps to test the PLC program. At this time, the Start pushbutton lamp should be off. A. Press the Start pushbutton momentarily. The clamp 1 cylinder should extend to hold the valve body in place. The start pushbutton lamp should turn on and remain on as this occurs. 81

82 B. Press the Start pushbutton momentarily. The screw insertion queue solenoid should turn on and insert a screw into the valve body, the solenoid will then turn off and the screw is pushed the rest of the way into the valve body by the other screws in the queue. C. Press the Start pushbutton, momentarily. The clamp 1 cylinder should retract. D. Manually remove the valve body from the work surface. 15. Click the Monitor button to go offline from the processor. 16. Use the PLC programming software to place the PLC into Stop mode. 17. Print out a copy of the ladder logic program and place it in your portfolio. It will be used in your assessment. 18. Perform the following substeps to shut down the 87-MS5 Servo Robotic Assembly station. A. Close the LAD/STL/FBD Editor. B. Close the SIMATIC Manager. C. Turn off the PC and monitor. D. Turn the 87-MS5 s main power switch to Off. E. Perform a lockout/tagout on the system s electrical power source. F. Perform a lockout/tagout on the system s pneumatic power source. 82

83 OBJECTIVE 10 DESCRIBE A SEQUENCE OF OPERATION OF A SCREW THREAD ENGAGEMENT MODULE Industrial applications often use screw thread engagement modules, like the one shown in figure 79 to start the screw threads of one part into its mating part to prevent loss of either part during transport to the next workstation in the assembly process. In the example shown in figure 79, the PLC uses one signal to actuate the single-solenoid directional control valve to extend the cylinder (SOL6) and to start the motor starter (M1). CLAMP 2 SINGLE-SOLENOID DCV (SOL3) KNOB MAGNETIC REED SWITCHES MR2 VALVE ASSEMBLY SCREW HEAD MOTOR (M1) MR6 MR5 NON-SLIP SURFACE KNOB SPRING SINGLE-SOLENOID DCV (SOL6) NON-SLIP SURFACE Figure 79. Screw Thread Engagement Module Construction 83

84 Screw Thread Engagement modules are typically PLC controlled. The sequence will be similar to that shown in the table below. SCREW THREAD ENGAGEMENT MODULE SEQUENCE OF EVENTS STEP INPUT OUTPUT 1 Receive Start Input (S1 on) Extend Clamp 2 (SOL3 on) 2 Clamp 2 Extended (MR4 on) Extend Knob Cylinder/Start Motor (SOL6, M1 on) 3 Knob Cylinder Extended (MR5 on) Start time delay (Thread engagement timer starts) 4 Time Delay Ends (Thread engagement timer done) 5 Knob Cylinder Retracted (MR1 on) Retract Clamp 2 6 Clamp 2 Retracted Cycle Ends Turn Screw Motor Off/Retract Knob Cylinder Figure 80. Screw Thread Engagement Module Sequence of Operation 84

85 Initial Condition The screw thread engagement module must be in some pre-determined state before any sequence may take place. Many times this will be a state in which the clamp cylinder and the knob cylinder are retracted and the motor is off. In some cases, there may be an interlock indicating that motion at the source and/or destination station has stopped and it is now safe to transfer. One example would be that the source station s transfer table has stopped moving. If these initial conditions are not satisfied, the screw thread engagement module will not operate and the PLC controlling the module may even provide an alarm light or message to the operator, indicating that operator intervention is necessary. Note the quick exhaust shown on the power diagram for the clamp 2 cylinder. The clamp cylinder is a spring return cylinder and it must retract quickly so it does not interfere with the robot. The quick exhaust allows the air to leave the cylinder quickly, reducing the amount of pressure the cylinder has to overcome. This enables the cylinder to retract more quickly than it would without the quick exhaust. FROM SOURCE SOL3 CLAMP 2 MR4 CLAMP RETRACTED MR6 ON QUICK EXHAUST SOL6 RETRACTED MR6 MR5 RETRACTED MOTOR OFF KNOB ASSEMBLY 24 VDC GND M1 M1 SCREW MOTOR Figure 81. Initial Condition 85

86 Step 1: Receive Start Input, Extend Clamp 2 In this step, the PLC controlling the screw thread engagement module sequence receives an input to start the screw thread engagement sequence. The input may be from another workstation, and operator, or the manipulator tending the module. After receiving the input signal, the PLC turns on SOL3 to extend clamp 2. The clamp will hold the part in place while work is being performed on it. FROM SOURCE CLAMP 2 BEGINS TO EXTEND SOL3 CLAMP 2 MR4 SOL6 QUICK EXHAUST RETRACTED MR6 MR5 KNOB ASSEMBLY 24 VDC GND M1 M1 SCREW MOTOR Figure 82. Step 1: Receive Start Input, Extend Clamp 2 86

87 Step 2: Clamp 2 Extended, Extend Knob Cylinder/Start Screw Motor Once clamp 2 is extended (MR4 on), the PLC will send an output to both extend the knob cylinder (SOL6 on) and turn the screw motor on (M1 on). FROM SOURCE MR4 ON SOL3 CLAMP 2 MR4 QUICK EXHAUST RETRACTED MR6 MR5 BEGINS TO EXTEND MOTOR ON SOL6 KNOB ASSEMBLY 24 VDC GND M1 M1 SCREW MOTOR Figure 83. Step 2: Clamp 2 Extended, Extend Knob Cylinder/Start Screw Motor 87

88 Step 3: Knob Cylinder Extended, Start Time Delay After the knob cylinder has extended (MR5 on), a time delay is started to allow the motor time to turn the screw head so that the threads engage in the knob. FROM SOURCE SOL3 CLAMP 2 MR4 QUICK EXHAUST RETRACTED MR6 MR5 MR6 OFF MR5 ON SOL6 KNOB ASSEMBLY 24 VDC GND M1 M1 SCREW MOTOR Figure 84. Step 3: Knob Cylinder Extended, Start Time Delay 88

89 Step 4: Time Delay Times Out, Turn Screw Motor Off/Retract Knob Cylinder When the timer times out, the PLC turns off the output to SOL6 and M1, which allows the knob cylinder to retract and turns off the screw motor. The screw threads should be engaged in the knob at this time. FROM SOURCE SOL3 CLAMP 2 MR4 SOL6 QUICK EXHAUST RETRACTED MR6 MR5 BEGINS TO RETRACT MOTOR OFF KNOB ASSEMBLY 24 VDC GND M1 M1 SCREW MOTOR Figure 85. Step 4: Time Delay Times Out, Turn Screw Motor Off/Retract Knob Cylinder 89

90 Step 5: Knob Cylinder Retracted, Retract Clamp 2 Once the knob cylinder is retracted (MR6 on), the PLC de-energizes SOL3 and clamp 2 retracts. A short time delay allows the clamp time to fully retract. FROM SOURCE CLAMP 2 BEGINS TO RETRACT SOL3 CLAMP 2 MR4 MR6 ON MR5 OFF QUICK EXHAUST SOL6 RETRACTED MR6 MR5 RETRACTED KNOB ASSEMBLY 24 VDC GND M1 M1 SCREW MOTOR Figure 86. Step 5: Knob Cylinder Retracted, Retract Clamp 2 90

91 Step 6: Clamp 2 Retracted, Cycle Ends When the short clamp timer ends, the clamp is retracted and the cycle ends. The cycle will repeat when the completed assembly is removed, new parts placed in the module, and the start input is received again. FROM SOURCE SOL3 CLAMP 2 MR4 CLAMP RETRACTED QUICK EXHAUST SOL6 RETRACTED MR6 MR5 SCREW AND KNOB THREADS ENGAGED KNOB ASSEMBLY 24 VDC GND M1 M1 SCREW MOTOR Figure 87. Step 6: Clamp 2 Retracted, Cycle Ends The sequence just described is summarized by sequence diagram in figure 88. SCREW THREAD ENGAGEMENT MODULE SEQUENCE OF OPERATIONS INPUTS OUTPUTS Step Input Action Output Action Start PB Stop PB MR4 MR5 MR6 SOL3 SOL6/M1 T1 0 Start Condition Receive Start Input Extend Clamp 2 1/0 1 2 Clamp 2 Extended Extend Knob Cylinder/Start Motor Knob Cylinder Extended Start Time Delay Time Delay Ends Turn Bolt Motor Off/Retract Knob Cylinder Knob Cylinder Retracted Retract Clamp 2/Cycle Repeats Clamp 2 Retracted Cycle Ends 0 End Condition Figure 88. Sequence Diagram 91

92 SKILL 7 DESIGN A PLC PROGRAM THAT SEQUENCES A SCREW THREAD ENGAGEMENT MODULE Procedure Overview In this procedure, you will design and test a PLC program that uses a screw thread engagement module to engage the threads of the screw into the knob to hold the parts together for transport to the next workstation. 1. Design a PLC program given the following information. The general sequence, I/O diagram, and power diagram are as follows: General Sequence: 1) Pressing the Start pushbutton (PB1) enables the PLC program. 2) After clamp 2 is extended (MR4 on), SOL6 is energized, which extends the knob cylinder and turns on the bolt motor (M1). 3) Once the knob cylinder is extended (MR5 on), a short dwell timer (3 seconds) is started to allow the screw threads time to engage in the knob. 4) After the timer ends, the knob cylinder retracts and the bolt motor is shut off. 5) When the knob cylinder is fully retracted (MR6 on), SOL3 is de-energized allowing clamp 2 to retract. A short timer (1 second) is started to allow time for the cylinder to retract. Special Conditions: The Start pushbutton lamp will be off when the station is in its home position (clamp retracted, knob cylinder retracted). The Start pushbutton will turn solid as the station is operating. Pressing the Stop pushbutton at any time will cause the station to stop (or halt) at the end of its current step. Pressing the Start pushbutton will resume the sequence from that step. 92

93 INPUTS I/O DIAGRAM OUTPUTS PB MR4 MR5 START INPUT I0.0 CLAMP 2 I1.5 KNOB ASSEMBLY I2.0 Q4.7 CLAMP 2 EXTEND (SOL3) KNOB ASSEMBLY EXTEND/ MOTOR STARTER ON (SOL6) Q5.2 M1 MR6 KNOB ASSEMBLY RETRACTED I2.1 Figure 89. I/O Diagram FROM SOURCE SOL3 CLAMP 2 VALVE MR4 SOL6 QUICK EXHAUST RETRACTED MR6 MR5 KNOB ASSEMBLY VALVE 24 VDC GND M1 M1 SCREW MOTOR Figure 90. Power Diagram 93

94 SCREW THREAD ENGAGEMENT MODULE SEQUENCE OF OPERATIONS INPUTS OUTPUTS Step Input Action Output Action 0 Start Condition Receive Start Input Extend Clamp 2 1/0 1 2 Clamp 2 Extended Extend Knob Cylinder/Start Motor Knob Cylinder Extended Start Time Delay Time Delay Ends Turn Bolt Motor Off/Retract Knob Cylinder Knob Cylinder Retracted Retract Clamp Clamp 2 Retracted Cycle Ends 0 End Condition Figure 91. Sequence Diagram 2. Perform the following substeps to open the PLC programming software. A. Make sure that the interface from the personal computer to the PLC is connected. B. Power up the PC and monitor. C. Start the SIMATIC Manager. 3. Perform the following substeps to create a project. A. Create a Project named L7S6XXX where XXX represents your initials. B. Create an S7 Station object for the station and configure its hardware. C. Open Organizational Block OB1. D. Enter the program that you developed in Step 1 into Organizational Block OB1. E. Save OB1. 4. If the 87-MS5 Servo Robotic Assembly station is connected to another station, separate the stations. If the 87-MS5 Servo Robotic Assembly station is already disconnected, continue to Step 5. Start PB (I0.0) Stop PB (I0.1) MR4 (I1.5) MR5 (I2.0) MR6 (I2.1) SOL3 (Q4.7) SOL6/M1 (Q5.2) T1 94

95 5. Perform the following safety check before you begin working on the station. Make sure that you can answer yes to each item before proceeding. YES/NO SAFETY CHECKOUT Remove all obstructions from the work area Check for signs of damage to the equipment Wear tight fi tting clothing, roll up long sleeves, remove ties, scarves, jewelry, etc. Tie up long hair Remove any robot teach pendants from the work area Locate the emergency stop button Ensure that safety glasses are worn by people in the area Ensure that all people are outside any work envelopes Figure 92. Mechatronics Safety Check 6. Connect an air supply line to the station s air manifold quick connect. 7. Plug the station s power cable into a power outlet. 8. Perform the following substeps to power up the 87-MS5 Servo Robotic Assembly station. A. Remove the lockout/tagout device from the electric power source. B. Remove the lockout/tagout device from the pneumatic power source. C. Turn on the air to the station by shifting the lever on the lockout valve. D. Set the station s air supply regulator to 50 psi/ 345 kpa. E. Set the screw feed module s air supply to 12 psi/82.7 kpa. F. Turn the station s Main Power Switch to the On position. 9. Press the Output Power pushbutton to enable the PLC s outputs. 10. Perform the following substeps to download the project to the PLC. A. Reset the PLC. B. Download the SIMATIC 300 Station object to the PLC. Several dialogs will appear during the download. Click the appropriate response to continue downloading the program. The last dialog should ask if you wish to perform a complete (Warm) restart. E. Click Yes on the dialog to complete a warm restart. 11. Go online with the processor and monitor the OB1 Block. 12. Manually assemble a valve body with a spool and a screw. 95

96 13. Manually place the valve body assembly in the recess provided on the work surface, as shown in figure 93. At this time, the Start pushbutton indicator should be off indicating that the station is ready to run. KNOB/SPRING ASSEMBLY VALVE ASSEMBLY Figure 93. Valve Body and Knob/Spring Assembly Placement 14. Manually place a knob/spring assembly on the assembly fixture as shown in figure Press the Start pushbutton momentarily. The clamp 2 cylinder should extend to hold the valve body. 16. Press the Start pushbutton momentarily. The screw motor should start running and the knob assembly cylinder should extend, pushing the knob/spring assembly to join the screw of the valve body assembly. 17. Press the Start pushbutton momentarily. The motor should turn off and the knob assembly cylinder should retract. 18. Press the Start pushbutton momentarily. The clamp cylinder should retract. 19. Manually remove the assembly and verify the knob is threaded on the screw. 20. Click the Monitor button to go offline from the processor. 21. Use the PLC programming software to place the PLC into Stop mode. 96

97 22. Print out a copy of the ladder logic program and place it in your portfolio. It will be used in your assessment. 23. Perform the following substeps to shut down the 87-MS5 Servo Robotic Assembly station. A. Close the LAD/STL/FBD Editor. B. Close the SIMATIC Manager. C. Turn off the PC and monitor. D. Turn the 87-MS5 s main power switch to Off. E. Perform a lockout/tagout on the system s electrical power source. F. Perform a lockout/tagout on the system s pneumatic power source. 97

98 SEGMENT 3 SELF REVIEW 1. One type of part insertion module uses a to push parts into assemblies. 2. The part insertion module must be in some pre-determined state before any can take place. 3. Screw feed modules are typically equipped with a to detect the presence of screws. 4. Screw feed modules are typically controlled. 5. Industrial applications often use a screw thread engagement module to start the screw threads into its part. 6. Before the sequence can begin for a screw thread engagement module, the cylinder and the knob cylinder must be retracted and the motor must be off. 98

99 SEGMENT 4 STATION SEQUENCING OBJECTIVE 11 DESCRIBE A SEQUENCE OF OPERATION OF A SERVO ROBOTIC ASSEMBLY STATION The operation of a servo robotic assembly station typically combines several different assembly modules and one or more material handling devices all controlled by a single PLC program. An example of a servo robotic assembly station is shown in figure 94. This station is designed to insert a spool and screw into a valve assembly. A shuttle then moves the assembly to the screw thread engagement module where a knob and spring assembly is threaded onto the previously inserted screw. A servo robot places the valve body at the spool/screw insertion module, a knob and spring assembly at the screw thread engagement module, and removes the completed assembly to the next operation. SERVO ROBOT SCREW THREAD ENGAGEMENT MODULE SCREW AND SPOOL INSERTION MODULES Figure 94. Servo Robot Assembly Station 99

100 A typical servo robotic assembly stations sequence is similar to that shown in figure 95. This sequence is a combination of the spool insertion module, screw feed module, and the screw thread engagement module. SERVO ROBOTIC ASSEMBLY STATION SEQUENCE OF EVENTS STEP INPUT OUTPUT 1 Robot Receives Reset Signal (Robot Reset on) 2 Robot Sends Ready Signal/PLC Receives Start Input (Robot Ready, S1 on) 3 Robot Sends Ready Signal (Robot Ready on) Robot Places Knob/Spring Assembly (Robot Signal 1 on) Robot Places Valve Body (Robot Signal 2 on) Extend Clamp 1 (SOL2 on) 4 Clamp 1 Extended (MR3 on) Extend Spool Insertion Cylinder (SOL1 on) 5 Spool Insertion Cylinder Extended/ Screws Present in Queue (MR1, IND3 on) 6 First Time Delay Ends (Screw Timer 1 Done) 7 Second Time Delay Ends/Spool Insertion Cylinder Retracted (Screw Timer 2 Done, MR2 on) 8 Clamp 1 Retracted/Transport Cylinder Extended (LS1 on) 9 Transport Cylinder Retracted (LS2 on) Screw Feeder Queue On/Start First Time Delay (SOL4 on, Screw Insert Time Delay 1 Starts) Retract Spool Insertion Cylinder/ Screw Feeder Queue Off/Start Second Time Delay (Screw Insert Time Delay 2 Starts) Retract Clamp 1/Extend Transport Cylinder (SOL5 on) Retract Transport Cylinder Extend Clamp 2 (SOL3 on) 10 Clamp 2 Extended (MR4 on) Extend Knob Cylinder/Start Bolt Motor (SOL6, M1 on) 11 Knob Cylinder Extended (MR5 on) Start Time Delay (Thread Engagement Timer Starts) 12 Time Delay Ends (Thread Engagement Retract Knob Cylinder/Turn Motor Off Timer Done) 13 Knob Cylinder Retracted (MR6 on) Retract Clamp 2 14 Clamp 2 Retracted Assembly Complete/Robot Pick Up Assembly (Robot Signal 3 on) 15 Robot Ready Signal (Robot Ready on) Cycle Ends Figure 95. Sequence of Operations 100

101 SKILL 8 DESIGN A PLC PROGRAM THAT SEQUENCES A SERVO ROBOTIC ASSEMBLY STATION Procedure Overview In this procedure, you will design and test a PLC program that uses a part feeder, automatic screw feeder, part insertion module, screw feed module, and a screw thread engagement module to assemble a valve body as it progresses through the station. 1. Design a PLC program given the following information. The general sequence, I/O diagram, and power diagram are as follows: General Sequence: 1) Pressing the Start pushbutton (PB1) enables the PLC program, which turns on the Active lamp indicator and sends a signal to the robot, which will place a knob/spring assembly and go back to its ready state before then picking up and placing a valve body. 2) The robot ready signal causes the Clamp 1 cylinder to extend. 3) After the Clamp 1 cylinder is extended, indicated by MR3, the spool insertion cylinder is extended. 4) After the spool insertion cylinder is extended (MR1 on), the PLC looks at IND3 to verify there are screws present in the queue. 5) If IND3 is high, meaning there are screws present, then the PLC turns on SOL4 to activate the screw insertion queue. A timer starts (1 second) to give the queue cylinders time to perform the first part of the insertion. 6) After the time delay ends, SOL1 is de-energized, which retracts the spool insertion cylinder and SOL4 is turned off. A second time delay (1 second) starts to allow the screw insertion to complete. 7) When the second time delay ends, the clamp retracts. 8) The transport cylinder solenoid (SOL5) is energized, which causes the cylinder to extend, shuttling the part to the next module. 9) Once the transport is extended (LS1 on), it retracts. 10) When LS2 is on (cylinder retracted), SOL3 is energized to extend clamp 2. 11) After clamp 2 is extended (MR4 on), SOL6 is energized, which extends the knob cylinder and turns on the screw motor (M1). 101

102 12) Once the knob cylinder is extended (MR5 on), a short dwell timer (3 seconds) is started to allow the screw threads time to engage in the knob. 13) After the timer ends, the knob cylinder retracts and the screw motor is shut off. 14) When the knob cylinder is fully retracted (MR6 on), SOL3 is de-energized allowing clamp 2 to retract. A short timer (1 second) is started to allow time for the cylinder to retract. 15) Once the timer times out, the PLC signals the robot that the assembly is ready to be removed from the station. Special Conditions: The Start pushbutton lamp will be off when the station is in its home position (robot ready, spool feeder retracted, clamps retracted, transport retracted, and knob cylinder retracted/motor off). The Start pushbutton will turn solid as the station is operating. Pressing the Stop pushbutton at any time will cause the station to stop (or halt) at the end of its current step. Pressing the Start pushbutton will resume the sequence from that step. 102

103 PB1 I/O DIAGRAM START I0.0 Q4.0 ACTIVE LAMP PB2 STOP I0.1 Q4.5 SPOOL INSERTION (SOL 1) RESET I1.0 Q4.6 CLAMP 1 EXTEND (SOL 2) MR1 AUTO I1.1 SPOOL INSERTION I1.2 Q4.7 CLAMP 2 EXTEND (SOL 3) MR2 MR3 MR4 LS1 LS2 MR5 MR6 SPOOL INSERTION RETRACTED I1.3 CLAMP 1 I1.4 CLAMP 2 I1.5 TRANSPORT I1.6 TRANSPORT RETRACTED I1.7 KNOB ASSEMBLY I2.0 KNOB ASSEMBLY RETRACTED I2.1 SCREW INSERTION QUEUE (SOL 4) Q5.0 Q5.1 Q5.3 Q5.4 Q5.5 Q5.6 TRANSPORT EXTEND (SOL 5) KNOB ASSEMBLY EXTEND (SOL 6) Q5.2 Q5.7 SCREW MOTOR ON M1 SELECT 3-WAY SPOOL (SOL 7A) SELECT 4-WAY SPOOL (SOL 7B) ROBOT HANDSHAKE RESET ROBOT HANDSHAKE GET VALVE BODY ROBOT HANDSHAKE BODY SELECT/OFF LOAD MR7 SPOOL FEEDER I2.2 MR8 SPOOL FEEDER RETRACTED I2.3 IND1 3-WAY SPOOL PRESENT I2.4 IND2 4-WAY SPOOL PRESENT I2.5 IND3 3RD SCREW PRESENT I2.6 ROBOT READY HANDSHAKE I2.7 Figure 96. I/O Diagram 103

104 FROM SOURCE SOL1 RETRACTED MR2 SPOOL INSERTION MR1 SOL2 CLAMP 1 MR3 PNEUMATIC SCREW FEEDER TUBE SOL3 CLAMP 2 MR4 SOL4 SOL5 QUICK EXHAUST SCREW INSERTION QUEUE RETRACTED LS2 LS1 SCREW GUIDE QUEUE 1 SCREW GUIDE QUEUE 2 SCREW RESTRAINT QUEUE 3 TRANSPORT VALVE QUICK EXHAUST SOL6 RETRACTED MR6 MR5 QUICK EXHAUST KNOB ASSEMBLY VALVE SOL7A RETRACTED MR6 MR5 SPOOL FEEDER SOL7B 24 VDC GND M1 M1 SCREW MOTOR Figure 97. Power Diagram 104

105 Figure 98. Sequence Diagram 105

106 2. Perform the following substeps to open the PLC programming software. A. Make sure that the interface from the personal computer to the PLC is connected. B. Power up the PC and monitor. C. Start the SIMATIC Manager. 3. Perform the following substeps to create a project. A. Create a Project named L7S7XXX where XXX represents your initials. B. Create an S7 Station object for the station and configure its hardware. C. Open Organizational Block OB1. D. Enter the program that you developed in Step 1 into Organizational Block OB1. E. Save OB1. 4. If the 87-MS5 Servo Robotic Assembly station is connected to another station, separate the stations. If the 87-MS5 Servo Robotic Assembly station is already disconnected, continue to Step Perform the following safety check before you begin working on the station. Make sure that you can answer yes to each item before proceeding. YES/NO SAFETY CHECKOUT Remove all obstructions from the work area Check for signs of damage to the equipment Wear tight fi tting clothing, roll up long sleeves, remove ties, scarves, jewelry, etc. Tie up long hair Remove any robot teach pendants from the work area Locate the emergency stop button Ensure that safety glasses are worn by people in the area Ensure that all people are outside any work envelopes Figure 99. Mechatronics Safety Check 6. Connect an air supply line to the station s air manifold quick connect. 7. Plug the station s power cable into a power outlet. 8. Verify the feed stand and the parts bin have been installed on the station. If they have not, then install them. 9. Stock all of the part feeders. 106

107 10. Perform the following substeps to power up the 87-MS5 Servo Robotic Assembly station. A. Remove the lockout/tagout device from the electric power source. B. Remove the lockout/tagout device from the pneumatic power source. C. Turn on the air to the station by shifting the lever on the lockout valve. D. Set the station s air supply regulator to 50 psi/ 345 kpa. E. Set the screw feed module s air supply regulator to 12 psi/82.7 kpa. F. Turn the station s Main Power switch to the On position. 11. Press the Output Power pushbutton to enable the PLC s outputs. 12. Perform the following substeps to start up the robot. A. Turn on the power to the robot controller. B. Turn on the PC connected to the robot controller and start the Robot Control software. C. Open the Mechatronics robot program. This is mech.prg for the Pegasus or Saturn.prg for the Saturn. D. Enable the robot drives. E. Jog the robot to the quick home position. F. Home the robot. 13. Teach the pickup points for the parts as shown in figure 100. APPROACH 2 GRIP 3 Figure 100. Pick Up Points 107

108 You will only use the right side (when facing the feed stand) location. The function of each teach point is described as follows: Point 2 is a approach point above the valve body Point 3 is a grip point for grasping the valve body This point must be taught with the valve body placed in the robot gripper. 14. Perform the following substeps to run the robot program using the teach pendant or proceed to Step 15 to run the program using the Robot Control software. A. From the Main Menu, press [F4] RUN to enter the Run menu. B. Press [F1] STR. The teach pendant display will list the default file, Controller 1. C. Press the [NEXT] key. The program mech will appear in the teach pendant display. D. Press [ENTER] to run the program. The robot will retrieve a knob/spring assembly from the feeder and place it in the assembly fixture, and then move to a wait position. 15. Click on the Run button shown in the File Control toolbar. The robot will retrieve a knob/spring assembly from the feeder and place it in the assembly fixture, and then move to a wait position. 16. Use the DCVs manual overrides to home the pneumatic cylinders (robot ready, spool feeder retracted, clamps retracted, transport retracted, knob cylinder retracted and motor off). 17. Perform the following substeps to download the project to the PLC. A. Reset the PLC. B. Download the SIMATIC 300 Station object to the PLC. Several dialogs will appear during the download. Click the appropriate response to continue downloading the program. The last dialog should ask if you wish to perform a complete (Warm) restart. C. Click Yes on the dialog to complete a warm restart. 18. Go online with the processor and monitor the OB1 Block. 108

109 19. Manually place a good acrylic valve body in the recess provided on the feed stand, as shown in figure 101. This should have no effect on the Servo Robotic Assembly station, as the Start pushbutton has not yet been pressed. Figure 101. Valve Body Placement 20. Press and release the Start pushbutton. The robot should start and the Start pushbutton s active indicator should turn on indicating that the station is running. The following sequence should occur. The robot places the knob/spring assembly and then it will place a valve body and return to its ready position Clamp 1 will extend and the spool insertion cylinder will extend, pushing a spool into the valve body The screw insertion module will insert the screw part way into the spool The spool insertion cylinder will then retract and the screw insertion module will complete inserting the screw into the spool Clamp 1 will retract and the transport will shuttle the part to the knob/ spring assembly area Clamp 2 will extend The screw motor will turn on and the knob/spring cylinder will extend and push the knob toward the valve body causing the screwdriver bit to engage the screw head After a 3 second dwell time, the motor will turn off and the knob/spring cylinder will retract Clamp 2 will retract 109

110 The robot picks up the valve assembly and places it in the parts bin at the end of the station and then places another knob/spring assembly before it returns to its ready position 21. Place a good aluminum valve body in the recess provided on the feed stand. 22. Press and release the Start pushbutton. The same sequence should occur. 23. Place another good aluminum valve body in the recess provided on the feed stand. 24. Press and release the Start pushbutton. 25. Once the Servo Robotic Assembly station begins operation, press the Stop pushbutton to stop (or halt) the station after its current step. Once movement is complete, the station should stop. 26. Press the Start pushbutton. The station should resume operation from its current step. 27. Click the Monitor button to go offline from the processor. 28. Use the PLC programming software to place the PLC into Stop mode. 29. Print out a copy of the ladder logic program and place it in your portfolio. It will be used in your assessment. 30. Perform the following substeps to shutdown the robot controller and Robot Control software. A. Move the robot to the home position. B. Disable the Robot s drives. C. Close the Robot s Control software. D. Turn off the robot controller. 31. Perform the following substeps to shut down the 87-MS5 Servo Robotic Assembly station. A. Close the LAD/STL/FBD Editor. B. Close the SIMATIC Manager. C. Turn off the PC and monitor. D. Turn the 87-MS5 s main power switch to Off. E. Perform a lockout/tagout on the system s electrical power source. F. Perform a lockout/tagout on the system s pneumatic power source. 110

111 OBJECTIVE 12 DESCRIBE THE OPERATION OF A SERVO ROBOTIC ASSEMBLY STATION WITH MANUAL/ AUTO/ RESET FUNCTIONS Traditional operator panels usually include 2-position or 3-position selector switches to select the mode of operation, as shown in figure 102. Some of the modes that can be selected are Off, Manual, Automatic, and Reset. Figure 102. Operator Panel with Selector Switches AUTOMATIC Selecting the automatic mode causes the PLC program to disable the manual functions and enable the automatic functions. This is usually done by disabling a manual function or function block and enabling an automatic function or function block. After automatic mode is selected, certain initial conditions are usually required to be satisfied before the station s sequence can begin. These initial conditions are input signals monitored by the PLC to verify that the station s parts are in the home position and to verify that a part is present and ready to be processed. If the station s parts are not in the proper position, a visual indicator is usually displayed on the operator panel to indicate that the station is not in its home position. If the station s parts are not homed, the operator must either switch to manual mode and reposition the parts, or initiate a reset function to home the station. After the machine is homed and the automatic mode is selected, pressing a start pushbutton causes the station to perform its sequence automatically. After the sequence has been completed, the station repeats the cycle. 111

112 MANUAL Selecting the manual mode causes the PLC program to enable the machine s manual functions. This is usually done in program logic by enabling a function or function block containing the manual operations while disabling functions and/or function blocks supporting the machine s other operating modes. Placing a machine in manual mode enables the user to move the machine s actuators on an as needed basis and is rarely used for production purposes. Because of this, the manual mode is usually associated with maintenance operations. Maintenance personnel may use the manual mode to: test the operation of a machine, make adjustments to the machine and/or its sensors, or to recover from a machine malfunction. There are two versions of manual operation: standard manual operation and step. Manual (traditional) - In this version of manual operation, turning the selector switch to the Manual position typically enables pushbuttons and/ or other manual operators on the operator panel to be used to manipulate the machine s actuators. In the case of an assembly station, for example, the operator panel (or HMI) could have two pushbuttons for each of the station s cylinders, one to make the actuator extend and one to make it retract. Step - In this version of manual operation, a pushbutton or other manual operator is used to step the machine through the steps of its sequence, one step at a time. In the case of a robotic assembly application, pressing the pushbutton the first time would cause the robot to place the parts. Pressing the pushbutton a second time would cause the spool insertion cylinder to extend, and so forth. RESET A reset function is included in the PLC program to home the station. The PLC program is designed to return all actuators to their start positions when a selector switch is placed in the Reset position. The reset function can be programmed to cause all of the actuators to return to their start positions at the same time or it can be programmed to return them in a sequence. Depending on the physical layout of the station, returning all of the actuators at the same time may cause some actuators to interfere with others. In this case, the reset function must be programmed to perform a reset sequence. Using a sequence causes the actuators to return to the home position in an order that prevents interference with other actuators. 112

113 For example, a Servo Robotic Assembly station s spool insertion cylinder is extended. After the cylinder is extended, the cylinder is retracted so that the next part does not contact the cylinder. When all of the stations parts are in the home position, an indicator is provided on the operator panel. The indicator may be a dedicated Home lamp, or solid, off, or flashing indicators on the panel s pushbuttons. Figure 103. Servo Robotic Assembly Station in Reset Position 113

114 SKILL 9 DESIGN A PLC PROGRAM THAT PROVIDES MANUAL/ AUTO/ RESET FUNCTIONS FOR A SERVO ROBOTIC ASSEMBLY STATION Procedure Overview In this procedure, you will modify project L7S7XXX to add the Manual, Auto, and Reset Functions. 1. Modify project L7S7AXXX so as to provide the Manual, Auto, and Reset functions to the program. The general sequence, I/O diagram, and power diagram are as follows: General Sequence (Auto Mode): 1) Pressing the Start pushbutton (PB1) enables the PLC program, which turns on the Active lamp indicator and sends a signal to the robot, which will place a knob/spring assembly and then pick up and place a valve body. 2) The robot ready signal causes the Clamp 1 cylinder to extend. 3) After the Clamp 1 cylinder is extended, indicated by MR3, the spool insertion cylinder is extended. 4) After the spool insertion cylinder is extended (MR1), the PLC looks at IND3 to verify there are screws present in the queue. 5) If IND3 is high, meaning there are screws present, then the PLC turns on SOL4 to activate the screw insertion queue. A timer starts (1 second) to give the queue cylinders time to perform the first part of the insertion. 6) After the time delay ends, SOL1 is de-energized, which retracts the spool insertion cylinder and SOL4 is turned off. A second time delay (1 second) starts to allow the screw insertion to complete. 7) When the second time delay ends, the clamp retracts. 8) The transport cylinder solenoid (SOL5) is energized, which causes the cylinder to extend, shuttling the part to the next module. 9) Once the transport is extended (LS1 on), it retracts. 10) When LS2 is on (cylinder retracted), SOL3 is energized to extend clamp 2. 11) After clamp 2 is extended (MR4 on), SOL6 is energized, which extends the knob cylinder and turns on the screw motor (M1). 12) Once the knob cylinder is extended (MR5 on), a short dwell timer (3 seconds) is started to allow the screw threads time to engage in the knob. 114

115 13) After the timer ends, the knob cylinder retracts and the screw motor is shut off. 14) When the knob cylinder is fully retracted (MR6 on), SOL 3 is de-energized allowing clamp 2 to retract. A short timer (1 second) is started to allow time for the cylinder to retract. 15) Once the timer times out, the PLC signals the robot that the assembly is ready to be removed from the station. Special Conditions: (Auto Mode) The sequence cannot be started unless all cylinders are homed, the robot is ready, and the motor is off. The Start pushbutton lamp will be off when the system is reset. The Start pushbutton will turn solid as the station is operating. Pressing the Stop pushbutton at any time will cause the Servo Robotic Assembly station to stop (or halt) at the end of its current step. Pressing the Start pushbutton will resume the sequence from that step. (Manual Mode) Pressing the Start pushbutton while the selector switch is in the Manual position causes the Servo Robotic Assembly station to step-through its sequence, one step at a time. (Reset) Turning the selector switch to the Reset position causes the Servo Robotic Assembly station to reset its actuators and the queue counts. 115

116 PB1 I/O DIAGRAM START I0.0 Q4.0 ACTIVE LAMP PB2 STOP I0.1 Q4.5 SPOOL INSERTION (SOL1) RESET I1.0 Q4.6 CLAMP 1 EXTEND (SOL2) MR1 AUTO I1.1 SPOOL INSERTION I1.2 Q4.7 CLAMP 2 EXTEND (SOL3) MR2 MR3 MR4 LS1 LS2 MR5 MR6 SPOOL INSERTION RETRACTED I1.3 CLAMP 1 I1.4 CLAMP 2 I1.5 TRANSPORT I1.6 TRANSPORT RETRACTED I1.7 KNOB ASSEMBLY I2.0 KNOB ASSEMBLY RETRACTED I2.1 SCREW INSERTION QUEUE (SOL4) Q5.0 Q5.1 Q5.3 Q5.4 Q5.5 Q5.6 TRANSPORT EXTEND (SOL5) KNOB ASSEMBLY EXTEND (SOL6) Q5.2 Q5.7 SCREW MOTOR ON M1 SELECT 3-WAY SPOOL (SOL7A) SELECT 4-WAY SPOOL (SOL7B) ROBOT HANDSHAKE RESET ROBOT HANDSHAKE GET VALVE BODY ROBOT HANDSHAKE BODY SELECT/OFF LOAD MR7 SPOOL FEEDER I2.2 MR8 SPOOL FEEDER RETRACTED I2.3 IND1 3-WAY SPOOL PRESENT I2.4 IND2 4-WAY SPOOL PRESENT I2.5 IND3 3RD SCREW PRESENT I2.6 ROBOT READY HANDSHAKE I2.7 Figure 104. I/O Diagram 116

117 FROM SOURCE SOL1 RETRACTED MR2 SPOOL INSERTION MR1 SOL2 CLAMP 1 MR3 PNEUMATIC SCREW FEEDER TUBE SOL3 CLAMP 2 MR4 SOL4 SOL5 QUICK EXHAUST SCREW INSERTION QUEUE RETRACTED LS2 LS1 SCREW GUIDE QUEUE 1 SCREW GUIDE QUEUE 2 SCREW RESTRAINT QUEUE 3 TRANSPORT VALVE SOL6 RETRACTED MR6 MR5 KNOB ASSEMBLY VALVE SOL7A RETRACTED MR6 MR5 SPOOL FEEDER SOL7B 24 VDC GND M1 M1 SCREW MOTOR Figure 105. Power Diagram 117

118 Figure 106. Sequence Diagram 118