LEARNING ACTIVITY PACKET MECHATRONICS AUTOMATION OPERATIONS B72001-AA01UEN

Transcription

1 MECHATRONICS LEARNING ACTIVITY PACKET AUTOMATION OPERATIONS B72001-AA01UEN

2 LEARNING ACTIVITY PACKET 1 AUTOMATION OPERATIONS INTRODUCTION As manufacturing industries strive to be successful in a highly competitive environment, they are increasing their use of more sophisticated automation systems. These systems frequently involve higher speeds, more precision, and integration of IT networks. Mechatronics is the field of study that produces operators, technicians, and engineers who are qualified to support these sophisticated automation systems. Mechatronics workers must have not only knowledge of the various automation components but also understand systems and integration of these components. This LAP serves as an introduction to mechatronics systems and teaches the basic concepts of automated machine operation. ITEMS NEEDED Amatrol Supplied One or more of the following Mechatronics Stations: 87-MS1 Pick and Place Feeding Station 87-MS2 Gauging Station 87-MS3 Indexing Station 87-MS4 Sorting and Queuing Station 87-MS5 Servo Robotic Assembly Station 87-MS6 Torquing Station 87-MS7 Parts Storage Station 870-PS7313-AAU, 870-PS7314-AAU, or 870-PS7315-AAU Mechatronics Learning System for Siemens S one per station Siemens Step 7 Programming Software - one per station Siemens S7-300 Programming Cable School Supplied Computer with Windows XP Operating System FIRST EDITION, LAP 1, 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 INTRODUCTION TO MECHATRONICS OBJECTIVE 1 Defi ne mechatronics OBJECTIVE 2 Defi ne a pick and place automation system and give an application OBJECTIVE 3 Defi ne a fl exible manufacturing system and give an application OBJECTIVE 4 Describe six automated manufacturing processes SEGMENT 2 CONTROL SYSTEM CONCEPTS OBJECTIVE 5 Defi ne the basic sequencing control systems model OBJECTIVE 6 Describe three types of manual discrete logic input devices OBJECTIVE 7 Describe four types of manual discrete logic output devices OBJECTIVE 8 Describe nine types of automatic discrete logic input devices OBJECTIVE 9 Describe two types of automatic discrete logic output devices SKILL 1 Identify control system component types SEGMENT 3 MECHATRONICS SAFETY OBJECTIVE 10 Describe eight mechatronics operator safe dress rules OBJECTIVE 11 Describe eight mechatronics operator safety rules OBJECTIVE 12 Describe the operation of an electrical lockout/tagout system SKILL 2 Perform a lockout/tagout on an electrical system OBJECTIVE 13 Describe the operation of a pneumatic lockout/tagout system SKILL 3 Perform a lockout/tagout on a pneumatic system SEGMENT 4 MACHINE OPERATOR FUNCTIONS OBJECTIVE 14 Describe the role of a modern automated machine operator OBJECTIVE 15 Describe the function of a basic operator panel OBJECTIVE 16 Describe the operation of three categories of stop functions OBJECTIVE 17 Describe how to operate an automated machine SKILL 4 Power up an automated machine 3

4 SEGMENT 1 INTRODUCTION TO MECHATRONICS OBJECTIVE 1 DEFINE MECHATRONICS Mechatronics is a field of study that focuses on the integration of mechanical, electrical, fluid, and computer technologies to control machine movements. The term mechatronics was introduced in the early 1970 s by a Japanese firm to describe the advent of mechanical equipment (mecha) that uses electronics (tronics) for decision-making functions. Today, the decision-making function is most often performed by a computer. MECHANICS ELECTRO MECHANICAL ELECTRONICS CAD/CAM MECHATRONICS CONTROL CIRCUITS SOFTWARE DIGITAL CONTROL CONTROL Figure 1. Mechatronics 4

5 An example of a typical mechatronics application is an assembly line that uses robots and other specialized automated devices to assemble parts. Material is often transported between stations by a conveyor. These systems typically use various types of electrical sensors to monitor machine operation and/or one or more programmable controllers to control machine movements. These controllers are commonly networked to provide communications between stations and to track the process. CNC MILL CNC LATHE ROBOT PARTS RACK VIBRATORY BOWL FEEDER ROBOT ASSEMBLY FIXTURE CONVEYOR Figure 2. Assembly Line 5

6 OBJECTIVE 2 DEFINE A PICK AND PLACE AUTOMATION SYSTEM AND GIVE AN APPLICATION Pick and place automation refers to control system applications that involve picking up parts from one location and placing them in another specific location. Figure 3. Pick and Place System 6

7 Pick and place automation systems are typically controlled by a PLC, often using solenoid-operated pneumatic or hydraulic valves to control machine movements, although they can also be servo-controlled. A pick and place system is used for material handling applications such as machine loading and unloading as well as sequential assembly operations, where each pick and place device performs one step of a multiple step automated assembly process. TRANSFER CONVEYOR B CONVEYOR A Figure 4. Pick and Place Application 7

8 OBJECTIVE 3 DEFINE A FLEXIBLE MANUFACTURING SYSTEM AND GIVE AN APPLICATION While automation systems can be applied to fixed applications, where they are designed to make a specific product, they are increasingly used in flexible manufacturing systems. A flexible manufacturing system, or FMS, consists of a group of automated machines linked by a material handling system and a controller that can be programmed to make a variety of products, product styles, or parts. WORK CENTER 1 WORK CENTER 2 Figure 5. Flexible Manufacturing System One advantage of an FMS is that it reduces cost. The reasons include: One set of equipment can produce multiple products, so less equipment is needed to produce multiple products Set-up time is reduced because the system can be reprogrammed to change products instead of being physically retooled Small batch runs of each product can be produced because product changes can be done by reprogramming, so inventory costs are less 8

9 An example of a small FMS is a system that consists of one or two CNC machining stations loaded by a robot and centrally controlled by a programmable controller. The robot automatically loads raw material and unloads finished parts for each CNC machine. The PLC can be programmed to signal the robot and CNC machine to change programs automatically to make a variety of products or parts. PLC CELL CONTROL CNC MACHINING CENTER #1 CNC MACHINING CENTER #2 ROBOT CONTROL ROBOT MATERIAL FEED FINISHED GOODS CONVEYOR Figure 6. Small FMS 9

10 An example of a large FMS is a system that consists of multiple stations or workstation, linked by a programmable material handling device such as a conveyor. Parts are moved from station to station under control of a central computer, often a PLC, with each station performing a different part of the manufacturing process. The central PLC can be programmed to signal the machines at each station to change their programs to produce different products or product styles. In many cases, each station also has a PLC to communicate with the control PLC and manage functions at that station. 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 7. Large FMS The first applications of flexible manufacturing systems were in machining of parts for aerospace and automotive industries, but the FMS concept has been applied to virtually all types of manufacturing and manufacturing processes. 10

11 OBJECTIVE 4 DESCRIBE SIX AUTOMATED MANUFACTURING PROCESSES Automation is used in many types of manufacturing processes. Some examples of manufacturing processes that are commonly automated include: inventory storage and retrieval, material handling, material processing, finishing, assembly (pick and place devices in sequence, welding, gluing, or robotic fastener assembly), and inspection. RAW MATERIAL MATERIAL REMOVAL FINISHING ASSEMBLY INSPECTION TESTING FINISHED PRODUCT Figure 8. Automated Manufacturing Process Flow Chart Inventory Storage and Retrieval An automated inventory storage and retrieval system (ASRS) is an automated machine that automatically provides raw material to the manufacturing process and stores finished goods. One form of an automated storage and retrieval system is a specialized robot-like device that loads and unloads parts from inventory warehouse racks. Figure 9. Inventory Storage and Retrieval System An ASRS can be either centralized or decentralized. The centralized inventory system has all inventory contained in one central location, as in figure 9. These systems are often quite large. 11

12 A decentralized system is where materials are fed to the required process at the workstations. In this type of system, the parts can be fed by parts feeders, such as gravity or vibratory bowl feeders, or placed with robots. FEEDER SYSTEM ASSEMBLY PARTS BIN CONVEYOR Figure 10. Decentralized Inventory Systems Material Handling A flexible material handling system, or FMH system, consists of one or more machines that automatically move material between workstations. It can be programmed to move material to the specific workstations needed by the process for a specific part or product. Two types of flexible material handling systems are programmable conveyors and automated guided vehicles (AGVs). Figure 11. Material Handling System 12

13 A conveyor is a device that transports material over specific paths using a running belt or chain. A programmable conveyor uses a computer of some type, usually a PLC, to move material to specific positions along its length that correspond to the locations of workstations where the materials are needed for the manufacturing process. PALLET STATION #1 STATION #2 STATION #4 STATION #3 Figure 12. Conveyor Two types of programmable conveyors used with an FMS are synchronous and asynchronous. A synchronous conveyor indexes the movement of parts from station to station, making the path and cycle rate the same for each part. An asynchronous conveyor allows parts to move independently of each other. Each part can move to its next station when work on the part is completed at its current station. One type of synchronous conveyor is a pallet transfer conveyor that transports parts on pallets rather than directly on the conveyor. With this type of conveyor, the belt runs continuously and the pallets are stopped at stations by PLC-controlled station positioners. 13

14 One advantage of using pallets is that they have the same dimensions, no matter what material is on the pallet, so they can be guided in the same way and accurately stopped at each station. This allows the robots or other devices at each workstation to be programmed to move to known points at the pallet each time to pick up the part from the pallet or do work on the pallet. Figure 13. Pallet Transfer Conveyor 14

15 An automatic guided vehicle, or AGV, is an unmanned vehicle that transports materials between workstations by following a programmed path. This path is often defined by an electrical wire laid into the floor but other methods are used as well. Most AGV s have an on-board computer that directly controls the operation of the vehicle. Some vehicles are pre-programmed with a specific path and others communicate with a remote computer via radio frequency (RF) communications to get instructions for the destination of each material. Figure 14. AGV System AGV s are common substitutes for a conveyor when the distance between workstations is very large or the conveyor structure blocks the movement of people or other processes. 15

16 Material Processing Material processing workstations usually consist of one or more computer numerical controlled (CNC) machines that perform a specialized material process and a robot to load and unload the workpiece from each machine. Material processes include: machining, casting, and molding. Machining includes material removal such as milling, turning, and grinding. Other material removal processes can include laser cutting, water jet cutting, EDM, and routing. Figure 15. Material Processing 16

17 Finishing Finishing processes improve the appearance or provide a protective coating to a part or product. Examples include polishing, grinding, trimming, painting, anodizing, and chrome plating. Finishing workstations commonly use robots to directly perform the finishing task by guiding the movement of a finishing device of some type such as a paint gun or polishing tool. Auto body painting is one of the most common examples of an FMS finishing application. Figure 16. Finishing Process 17

18 Assembly Assembly is the process of joining two or more separate parts. Assembly processes include mechanical fastening operations that use screws, nuts, rivets, or adhesives. Also included are processes such as welding, brazing, soldering, and gluing. Automated assembly workstations use robots or PLC-controlled pick and place devices to assemble parts. FEEDER SYSTEM ASSEMBLY PARTS BIN CONVEYOR Figure 17. Assembly Process 18

19 Inspection Inspection is the process of determining if the part or product meets one or more design specifications. Common inspection processes include measurement of part dimensions by a gauging device of some type, vision inspection of product assemblies, or functional testing of product operation. Inspection workstations load parts into specialized inspection machines or the inspection device may be designed to test the device directly on the material handling system. Electronic circuit boards are commonly inspected by vision systems to make sure that all components are assembled. Figure 18. Inspection Station 19

20 SEGMENT 1 SELF REVIEW 1. The decision making function of mechatronics is performed mostly by. 2. Pick and place automation systems are controlled by a. 3. One reason an FMS can reduce cost is because one set of equipment can produce. 4. Automated storage and retrieval systems provide to the manufacturing process and store finished goods. 5. A decentralized ASRS feeds the materials directly to the. 6. Two types of are programmable conveyors and automated guided vehicles. 7. A(n) conveyor allows parts to move independently of each other. 8. An AGV transports materials between workstations by following a. 9. Material processes include machining, casting, and. 10. Assembly processes include mechanical fastening, welding, brazing, soldering, and. 20

21 SEGMENT 2 CONTROL SYSTEM CONCEPTS OBJECTIVE 5 DEFINE THE BASIC SEQUENCING CONTROL SYSTEMS MODEL While automation systems can vary widely in design and purpose, they generally have a controller that is programmed or designed to make the machine components perform a series of actions or steps. This is called the machine sequence, and understanding this sequence is a key part of understanding the machine s operation. To perform a machine sequence, the controller is connected to various input and output devices and then programmed with logic so it turns certain outputs on or off in a sequence in response to receiving a specific sequence of input signals. Each step of a control system sequence starts with an input signal, or signals, the logic then decides what outputs to turn on or off, and the outputs turn on or off to make the machine step take place. INPUT LOGIC OUTPUT LIMIT SWITCH SIGNAL PLC PROGRAM LOGIC MOTOR STARTS Figure 19. Basic Control System Sequence Model 21

22 To create a sequence of steps, the input devices are physically arranged on the machine so the completion of one step s action triggers an input device to signal the controller to start the next step. The multi-step sequence is represented by a series of basic sequence models where the output of the previous step triggers an input device to make the next step take place. For example, consider the clamp and drill sequence example shown in figure 20, which consists of two actuators performing a 4-step sequence. The sequence is: Step 1: Clamp cylinder extend Step 2: Drill cylinder extend Step 3: Drill cylinder retract Step 4: Clamp cylinder retract DRILL CYLINDER DRILL PART LS1 LS2 CLAMP CYLINDER LS3 LS4 PB1 START STOP PLC MOUNTED INSIDE Figure 20. Clamp and Drill Application The logic diagram for this clamp and drill sequence is shown in figure 21. Here you can see which input triggers a particular output in the sequence. When the operator presses PB1 to start the sequence, the clamp cylinder extends. When the clamp cylinder is extended, it actuates LS3, which starts step 2 of the sequence, drill cylinder extend. 22

23 When the drill cylinder becomes extended, it actuates LS2, which starts step 3, drill cylinder retract. In this case, the controller turns off an output to cause this step to occur. When the drill cylinder becomes retracted, it actuates LS1, which starts step 4, clamp cylinder retract. Again, the controller turns off an output to cause this step to occur. When the clamp cylinder is retracted, it actuates LS4, which stops the sequence. INPUTS LOGIC OUTPUTS STEP 1 OPERATOR PRESSES PB1 PB1 ON/ OFF PLC LOGIC CLAMP CYLINDER EXTENDS SOL 2A ON CLAMP CYLINDER EXTENDED DRILL CYLINDER EXTENDS 2 LS3 ON PLC LOGIC SOL 1A ON DRILL CYLINDER EXTENDED DRILL CYLINDER RETRACTS 3 LS2 ON PLC LOGIC SOL 1A OFF DRILL CYLINDER RETRACTED CLAMP CYLINDER RETRACTS 4 LS1 PLC ON LOGIC SOL 2A OFF CLAMP CYLINDER RETRACTED CYCLE STOPS 5 LS4 ON PLC LOGIC NO OUTPUT CHANGE Figure 21. Clamp and Drill Cylinder Sequence 23

24 OBJECTIVE 6 DESCRIBE THREE TYPES OF MANUAL DISCRETE LOGIC INPUT DEVICES Most automated machines have a control panel that allows the operator to control and monitor the basic functions of the machine such as start, stop, and mode select. The most basic type of control panel consists of pushbuttons, selector switches of various types, and BCD (binary coded decimal) thumbwheels wired to the discrete input terminals of the PLC. Figure 22. Control Panel 24

25 Pushbutton Switches Pushbutton switches are used in control systems to manually send input signals to the controller to cause it to perform functions such as starting and stopping the machine. Pushbutton switches can be either momentary or maintained. A momentary switch contains a spring that causes the operator to return to its original position and the contacts to return to their normal state once the person releases the button. A maintained pushbutton stays pushed in and holds the contacts in the actuated state after the person releases the button. To de-actuate the contacts, the person must pull out the button or push it a second time. Pushbuttons are available with a variety of operator types and colors to provide easy operation and identification. The mushroom head pushbutton is designed so the operator can quickly locate and press the button. This is reserved for functions such as Emergency Stop. The extended button extends beyond the body of the operator so that the color of this operator can be easily seen from all angles. The flush button is guarded by the button body to prevent accidental actuation. This button is often used as a start button. MUSHROOM HEAD FLUSH BUTTON EXTENDED BUTTON Figure 23. Pushbuttons 25

26 Selector Switches A selector switch is a type of manual switch that operates its contacts by rotating the operator into a position. It is used most often to change the mode of operation of a machine, such as On/Off, Manual/Automatic, Run/Jog, and Forward/Reverse. Common selector switches can have either two or three positions, and either momentary or maintained contacts. The maintained types stay in the position set by the operator, while the spring return, or momentary types, return to the starting position once it is released. SELECTOR SWITCHES Figure 24. Selector Switches 26

27 BCD Thumbwheel Switch A BCD thumbwheel switch provides multiple inputs to a controller or PLC to enable the operator to input data such as a time delay or production count. The BCD thumbwheel switch consists of four parallel switches controlled by the thumbwheel. When the operator dials in a decimal number (0-9) on the display, the BCD thumbwheel sets each of its switches either on or off to form a BCD value corresponding to the decimal value displayed. For example, dialing in a decimal value of 3 would cause the switch to output 0011BCD on the four data lines. 16 POINT INPUT MODULE GROUP OF FOUR BCD THUMBWHEEL SWITCHES MOST SIGNIFICANT DIGIT LEAST SIGNIFICANT DIGIT +24V THUMBWHEEL Figure 25. BCD Thumbwheel A BCD thumbwheel switch is typically wired to four adjacent discrete inputs on an input module of a PLC. The PLC has an instruction that can read the four inputs as a group and create a decimal number. 27

28 OBJECTIVE 7 DESCRIBE FOUR TYPES OF MANUAL DISCRETE LOGIC OUTPUT DEVICES In addition to manual input devices most operator panels include manual output devices as well. These manual output devices include indicator lamps of various types, audible alarms, message displays, and LED displays to help the operator monitor the status of the machine. Figure 26. Operator Panel Indicator Lamps Indicator lamps are used by electrical control systems to tell the operator at a glance the operating status of the machine. They have many uses, including indicating that power to a machine is on, a cycle has begun or ended, and a sensor has sensed an input. Figure 27. Indicator Lamps 28

29 Audible Alarms Audible alarms are used to alert the operator to an event that needs immediate attention. An alarm may turn on if a part or feeder is jammed or if a liquid temperature goes beyond the range limits. Figure 28. Alarm Message Displays Message displays are used to display information to the operator and maintenance personnel about the status of a machine or process. They store preprogrammed messages that are displayed when the unit receives a signal from a programmable controller. Messages may be displayed to tell the operator what process is being performed on a part, the temperature of an oven, or that a piece of equipment has faulted. Figure 29. Message Display - Siemens AG 2006, All rights reserved t 29

30 LED Display An LED display is an output device that enables a machine operator to view the value stored in a PLC memory location without the use of a programming terminal. This enables the operator to view data such as the elapsed time for a time delay or a count representing the current production level. 16 POINT OUTPUT MODULE MOST SIGNIFICANT DIGIT LEAST SIGNIFICANT DIGIT 4 DIGIT LED OUTPUT DISPLAY STATUS OF DATA LINES Figure Digit LED Display Each decimal digit of an LED display is controlled by four data lines that are wired to four output terminals of a PLC output module. The digit displayed by each LED display is the decimal form of the BCD value the display receives from the PLC output module terminals. The operation of an LED display is the counterpart to the BCD thumbwheel switch. 30

31 OBJECTIVE 8 DESCRIBE NINE TYPES OF AUTOMATIC DISCRETE LOGIC INPUT DEVICES Sensors that are used to detect actuator position are called automatic input devices because the machine automatically triggers them. Many of these sensors are discrete types, which output an on or off signal. Eight types commonly-used on/off type sensors are: Limit switch Magnetic reed switch Capacitive proximity sensor Inductive proximity sensor Photoelectric proximity sensor Infrared proximity sensor Fiber optic proximity sensor Hall-effect sensor Giant magnetoresistive sensors Limit Switch A limit switch is an input switch used on automatic machines to sense the position of a machine member by mechanical means and convert the position into an electrical signal. This electrical signal is used by the control logic circuit to start a new step in the machine sequence. Limit switches are commonly used because they are low cost. However, since they use moving parts they do not last as long as electronic sensors. Figure 31. Limit Switches 31

32 Magnetic Reed Switch A magnetic reed switch is a fast-operating, electrical switch with normally open contacts that close when they encounter a magnetic field. They can only sense objects that generate a magnetic field. Magnetic reed switches are often used on aluminum cylinders in pneumatic applications to detect when the cylinder is at the end of its stroke. The cylinder piston is equipped with a magnet to trigger the switch. Magnetic reed switches are highly accurate, low cost, and long lasting. In light use, they can be used for billions of cycles. Figure 32. Magnetic Reed Switch Capacitive Proximity Sensor A capacitive proximity sensor uses the principle of capacitance to sense the presence of an object. It creates an electrostatic field that is used to sense when a part comes into range and turn on a transistor output. A capacitive proximity sensor can sense both metal and non-metallic objects. Figure 33. Capacitive Proximity Sensor 32

33 Inductive Proximity Sensor An inductive proximity sensor uses the principle of induction to sense the presence of a metallic object. It creates a magnetic field that is used to sense when a metal part comes into range and turn on a transistor output. Ferrous targets that contain iron, like steel, can be detected at greater distances than nonferrous targets such as aluminum. Inductive sensors are less expensive than capacitive sensors, so they are preferred if the object being detected is metal. Figure 34. Inductive Proximity Sensor Photoelectric Proximity Sensor A photoelectric sensor energizes its output when it senses light. The sensor is a solid-state device that uses a principle called photoconduction to operate. Photoconduction is the ability of a material to conduct electrical current when struck by light. Photoelectric sensors have a much greater sensing distance than other types of electronic sensors such as capacitive or inductive sensors. Figure 35. Photoelectric Sensor 33

34 Infrared Proximity Sensor An infrared proximity sensor is a photoelectric sensor that outputs infrared light rather than visible light. They are higher-powered photoelectric sensors and are suited for areas that contain a high amount of ambient light, which can affect visible light sensors. Figure 36. Infrared Sensor Fiber Optic Proximity Sensor A fiber optic sensor is a photoelectric sensor that uses fiber optic filaments attached to the photoelectric sensor to send and receive the light. The cables attached to the photoelectric sensor guide the light through the fiber optic filaments and out through the sensing head, while the cables attached to the receiver returns the light. Fiber optic sensors are used in tight sensing locations, extreme (highly corrosive or high moisture) or high temperature environments, and areas of high vibration and shock. SENSOR HEAD SIGNAL CONDITIONER Figure 37. Fiber Optic Sensor 34

35 Hall-Effect Sensor A Hall-effect sensor energizes its output when a magnetic field is sensed, just like a magnetic reed switch. The sensor is a solid-state device that operates on a principle called transduction, the Hall-effect. The Hall-effect is the ability of a conductive material to develop a voltage potential at right angles to current flow when subjected to magnetic fields. Hall-effect sensors are used instead of magnetic reed switches in operations where fast response time is needed. Because they are solid-state, Hall-effect switches react faster than reed switches. Figure 38. Hall-Effect Sensor 35

36 Giant Magnetoresistive Sensor A giant magnetoresistive (GMR) sensor is a magnetic sensor that responds mainly to the magnetic field orientation and direction rather than the magnetic field strength. This sensor is a solid-state device that operates on a principle called the giant magnetoresistive effect. The giant magnetoresistive effect is based on very thin layers of iron and other magnetic metals with spacer layers of non-magnetic metal stacked between them. One layer of the magnetic metal is pinned in one direction through the use of a layer with a strong antiferromagnet. When a weak magnetic field passes under the sensor, the magnetic orientation in the unpinned magnetic layer rotates relative to the pinned layer, which generates a change in the electrical resistance due to the GMR effect. GMR sensors are very useful in non-contact position registration applications, such as distance, speed, and rotation measurements. These sensors are more sensitive than regular magnetic reed switches and therefore can be used in applications where magnetic reed switches cannot. Figure 39. Giant Magnetoresistive Sensor 36

37 OBJECTIVE 9 DESCRIBE TWO TYPES OF AUTOMATIC DISCRETE LOGIC OUTPUT DEVICES To operate an automated machine the controller must be connected to output devices that control the flow of power to the actuators. In non-servo fluid power systems, these output devices are typically solenoid-operated directional control valves (DCVs). In electric motor applications, the output device is a motor starter. Directional Control Valves DCV s control the motion of the actuators by controlling the direction of the fluid flow. DCV s are often operated by electric solenoids, which receive signals from the controller. DCV s are used to control cylinders, motors, and rotary actuators. Figure 40. Directional Control Valve 37

38 DCV s move in two directions. This can be accomplished by using one solenoid and a return spring, two solenoids alone, or two solenoids with return springs. As shown in figure 41, when the controller receives an input signal, it turns on one of its outputs, which turns on the solenoid. The valve shifts and provides fluid flow to power the actuator. OUTPUTS 24 VDC ACTUATOR RETURN SPRING SOLENOID ENERGIZED FROM AIR COMPRESSOR Figure 41. Activation of Directional Control Valve 38

39 Electric Motor Starters A magnetic motor starter functions as a large relay to start and stop a motor by opening and closing the power lines to the motor. A magnetic motor starter also includes overload protection, which stops the motor if it draws excessive power. Motor starters are used to control constant speed AC and DC motors. Figure 42. Magnetic Motor Starter 39

40 A PLC operates a motor starter by turning on one of its outputs. This output energizes a solenoid in the motor starter, which closes the starter s contacts and allows electrical power to flow through to the motor. OUTPUTS 24 VDC SOLENOID MOTOR L1 L2 L3 CONTACTOR MOTOR STARTER Figure 43. Activation of Magnetic Motor Starter 40

41 SKILL 1 IDENTIFY CONTROL SYSTEM COMPONENT TYPES Procedure Overview In this procedure, you will familiarize yourself with the functions of the various stations that make up the 870 Mechatronics learning system and its components. Your organization may have any number of the mechatronics stations. Review the ones that you have available to you. 1. Locate the 870 Mechatronics System shown in figure 44. This system is designed to assemble a family of pneumatic directional control valves. Figure Mechatronics System 41

42 Figure 45 shows the model number and description of each station. MODEL NAME 87-MS1 87-MS2 87-MS3 87-MS4 87-MS5 87-MS6 87-MS7 DESCRIPTION Pick and Place Feeding Station Gauging Station Indexing Station Sorting and Queuing Station Servo Robotic Assembly Station Torquing Station Parts Storage Station Figure 45. Mechatronics Stations 2. Perform the following substeps to familiarize yourself with station 1, which is the Model 87-MS1 Pick and Place Feeding station. This station uses a powered parts feeder to supply parts to a 2-axis pick and place manipulator. The pick and place manipulator picks up the parts from the feeder and places them in a bin or onto the next station, if attached. POWERED PARTS FEEDER 2-AXIS PICK AND PLACE MANIPULATOR PARTS BIN ELECTRO- PNEUMATIC VALVE MANIFOLD Figure 46. Pick and Place Feeding Station A. Locate the Powered Parts Feeder, shown in figure 46. This feeder uses a gravity parts feeder with a powered cylinder that pushes parts out to the pick up location. 42

43 B. Locate the 2-Axis Pick and Place manipulator, shown in figure 46. This pick and place unit uses a rodless cylinder and a cylinder with guide shafts controlled by solenoid operated DCV s and a vacuum gripper to pick up parts and place them in a different location. C. Locate the Electro-Pneumatic Valve Manifold, shown in figure 46. This valve manifold includes a 4-station manifold with one singlesolenoid, 2-position DCV, and three double-solenoid, 2-position detent DCV s, all with manual overrides. D. Locate the Parts Bin, shown in figure 46. This bin is used to hold the parts from the pick and place robot when Station 1 is not connected to other stations. E. Locate the Parts Set. The parts set includes eight acrylic valve bodies for use with this and subsequent stations. 3. Perform the following substeps to familiarize yourself with station 2, which is the Model 87-MS2 Gauging station. This station inspects valve bodies for correct port locations and for correct body thickness. If the ports are not positioned correctly, missing, or the body is not the correct height, the station will reject the part to a reject bin. Otherwise, it will push the part into a parts bin or on to the next station, if attached. PROXIMITY GAUGING MODULE PART TRANSFER MODULE ULTRASONIC MEASUREMENT MODULE TRAVERSE SHUTTLE PART REJECT MODULE ELECTRO- PNEUMATIC VALVE MANIFOLD Figure 47. Gauging Station 43

44 A. Locate the Traverse Shuttle, shown in figure 47. The traverse shuttle uses a DC motor controlled by a reversing motor starter. It also has a clutch to drive a synchronous belt that is connected to a precision ball screw. A carriage is mounted onto the traverse to hold and carry the valve body. B. Locate the Ultrasonic Measurement Module, shown in figure 47. The ultrasonic measurement module uses an ultrasonic sensor mounted on a stand over the traverse to measure the height of the valve body. C. Locate the Proximity Gauging Module, shown in figure 47. The proximity gauging module uses a diffused mode infrared proximity sensor to detect the presence of a port in the valve body. If the port is missing or if the valve body is oriented incorrectly and the port is not in the specified location, the valve body is rejected. D. Locate the Part Transfer Module, shown in figure 47. The part transfer module uses two pneumatic cylinders to move the valve body. One vertical, single-acting cylinder located under the carriage pushes the part up and out of the carriage recess so that the part reject cylinder or part transfer cylinder can push the part off the carriage. The part transfer cylinder uses a cylinder with magnetic reed switches for location sensing. This cylinder pushes the valve body into a bin or onto the next station, if attached. E. Locate the Part Reject Module, shown in figure 47. The part reject module uses the same kind of cylinder as the part transfer module, but it pushes the valve bodies into a reject bin where they have to be manually removed. F. Locate the Electro-Pneumatic Valve Manifold, shown in figure 47. This valve manifold includes a 3-station manifold with two single-solenoid, 2-position DCV s, and one double-solenoid, 2-position detented DCV, all with manual overrides. G. Locate the Parts Set. The parts set includes four acrylic reject valve bodies for use with this and subsequent stations. It also includes two aluminum gauge blocks used in programming the ultrasonic sensor. 44

45 4. Perform the following substeps to familiarize yourself with station 3, which is the Model 87-MS3 Indexing station. This station checks the orientation of the valve body. If it is in the correct orientation, it moves the valve body to a part transfer module, where it is moved to a bin or to the next station. If the valve body is not in the correct orientation, it is indexed to the pick and place manipulator, which puts it into the correct orientation and then it is indexed to the part transfer module for movement to a bin or to the next station. ROTARY INDEX TABLE FIBER OPTIC GAUGING MODULE PICK AND PLACE MANIPULATOR PART TRANSFER MODULE ELECTRO- PNEUMATIC VALVE MANIFOLD Figure 48. Indexing Station A. Locate the 8-Station Rotary Index Table, shown in figure 48. The rotary index table has a round 8-station table mounted to a stepper motor with on-board intelligent control. This allows the motor to be stopped at specific positions. The table uses two capacitive proximity sensors to sense the presence of a valve body, one at the initial location and one at the orientation location. B. Locate the Pick and Place Pneumatic Manipulator, shown in figure 48. The pick and place manipulator uses a curvilinear 2-point gripper and a rotary actuator to orient the valve bodies. When a valve body arrives at the orientation location, the manipulator lowers and the gripper grips the part. The manipulator then moves up, rotates 180, and lowers again to place the part back on the index table. 45

46 C. Locate the Fiber Optic Gauging Module, shown in figure 48. The fiber optic gauging module uses a fiber optic photoelectric sensor to locate the presence of a port in the valve body. This tells the system if the part has to be reoriented or if it can be moved on to the part transfer module. D. Locate the Part Transfer Module, shown in figure 48. The part transfer module uses a pneumatic cylinder with magnetic reed switches for location sensing. When the system indexes a valve body to the part transfer module, the cylinder extends and pushes the part into a bin or onto the next station, if attached. E. Locate the Electro-Pneumatic Valve Manifold, shown in figure 48. This valve manifold includes a 4-station manifold with one singlesolenoid, 2-position DCV, and three double-solenoid, 2-position detent DCV s, all with manual overrides. 5. Perform the following substeps to familiarize yourself with station 4, which is the Model 87-MS4 Sorting and Queuing station. This station sorts the aluminum valve bodies from the acrylic bodies. When the valve body is placed on the end of the conveyor, a photoelectric sensor detects the part and an inductive sensor detects if it is aluminum. The parts are sorted according to the material, pushing one material type to the far side of the conveyor while leaving the other material type on the near side. The valve bodies then continue down the conveyor. The last section of the conveyor has a sorter/buffer to keep the parts separated. The valve bodies stay on the conveyor until picked up by the next station or manually removed. PART SORTING MODULE BELT CONVEYOR MODULE PROXIMITY SENSING MODULE BUFFER MODULE ELECTRO- PNEUMATIC VALVE MANIFOLD Figure 49. Sorting and Queuing Station 46

47 A. Locate the Belt Conveyor Module, shown in figure 49. The belt conveyor is a fixed speed conveyor, which is powered by an electric motor. At the beginning of the conveyor, a photoelectric switch is used to sense when there is a part on the conveyor. B. Locate the Part Sorting Module, shown in figure 49. The part sorting module uses an inductive sensor along with the capacitive proximity sensor at the beginning of the conveyor to detect if the valve body is aluminum. If both sensors see the valve body, indicating it is metal, a cylinder with a push bar extends to push the metal body to the other side of the conveyor where it will continue down the conveyor. If the inductive sensor does not sense the part, but the capacitive proximity sensor does, indicating the part is not metal, it is sent down the near side of the conveyor. C. Locate the Buffer Modules, shown in figure 49. The two buffer modules consist of formed sheet steel channels to separate the acrylic parts from the aluminum parts. Because the valve bodies ride on the conveyor they would stack up at the end of the conveyor, making it difficult for any automated system to remove them. To prevent this, each channel has a restraining arm mechanism that is controlled by a singleacting cylinder. When the arm moves to let a valve body move to the end of the conveyor, the back of the arm rotates and grips the next body in line to prevent it from moving. Once the first part clears the area, the arm snaps back into position to allow the next part to move into the pickup position. D. Locate the Proximity Sensing Module, shown in figure 49. The proximity sensing module uses a retro-reflective proximity sensor to detect valve bodies in the pick up location at the buffering station. E. Locate the Electro-Pneumatic Valve Manifold, shown in figure 49. This valve manifold includes a 3-station manifold with one single-solenoid, 2-position DCV, and two double-solenoid, 2-position detent DCV s, all with manual overrides. F. Locate the Parts Set. The parts set includes eight aluminum valve bodies for use with this and subsequent stations. This set adds to the acrylic parts set supplied with station 1. 47

48 6. Perform the following substeps to familiarize yourself with station 5, which is the Model 87-MS5 Servo Robotic Assembly station. This station assembles the valve by installing the spool, screw, spring, and knob. It uses a servo robot to assist in placement and orientation of the valve body. The valve is assembled in two stages. In the position next to the spool insertion module, the spool and screw are inserted. After this step takes place, the valve is moved to the second assembly position where the spring and knob are attached. The robot used with the assembly station will be a Pegasus or a Saturn. SCREW FEEDER VALVE CLAMP MODULES SPRING / KNOB ASSEMBLY FEEDER SPRING / KNOB ASSEMBLY MODULE ELECTRO- PNEUMATIC VALVE MANIFOLD SCREW INSERTION MODULE PART INDEX MODULE SPOOL FEEDER MODULE Figure 50. Servo Robotic Assembly Station A. Locate the Valve Clamp Modules, shown in figure 50. The valve clamp modules, one located at the spool insertion module and one at the spring/knob assembly module, use pneumatic cylinders to hold the valve bodies in place during assembly. These cylinders each have one magnetic reed switch to tell the system when the part is clamped. B. Locate the Spool Feeder Module, shown in figure 50. The spool feeder module is a gravity feeder that stores both 4-way and 3-way spools. The feeder is attached to a cylinder that positions the feeder to its extended position or retracted position to allow the installation of the desired spool into the valve body. 48

49 C. Locate the Spool Insertion Module, shown in figure 50. The spool insertion module uses a pneumatic cylinder with magnetic reed location switches on either end. On the end of the cylinder rod is a tapered tip that is designed to push through the bottom of the spool feeder and push the spool into the valve body. Once a spool is pushed out of the feeder, the remaining spools in the magazine drop down on the cylinder rod while it is extended. The tapered shape of the tip allows the cylinder to retract without catching the edge of the next spool on the retract stroke. D. Locate the Screw Feeder, shown in figure 50. The screw feeder is a pneumatic tube feeder that uses compressed air to push the screws to the insertion location. This feeder s air supply has a its own regulator because it only requires approximately 10 psi to feed the screws. It also has a parts presence sensor that tells you if the feeder is empty or not. Note that the parts presence sensor detects the bolt that is the third one back from the one ready for insertion. E. Locate the Screw Insertion Module, shown in figure 50. The screw insertion module includes three pneumatic cylinders. One cylinder is used as a part restraint, which keeps the parts from entering the assembly location at the wrong time. The other two cylinders are used to line up the part for assembly. The screw feeder holds a screw ready and when the spool is inserted, it is actually extended over the end of the screw, which aids in the screw insertion. Once the screw is inserted, the part is indexed to the second assembly position. During this travel, the assembly goes through a fixture that pushes the screw/spool assembly further into the valve body. F. Locate the Part Index Module, shown in figure 50. The part index module is a rodless cylinder that is mounted underneath the assembly work surface. Attached to it and extending up through the work surface is a tab that is used to push the part from one assembly module to the other. This cylinder has end of travel limit switches attached to each end. G. Locate the Spring/Knob Assembly Feeder, shown in figure 50. The spring/knob assembly feeder is a gravity feeder with a small, moveable stop at the bottom. This feeder holds the assembled spring and knob in the knob down orientation. It is designed to allow the robot to remove the assembly and place it in the assembly module. 49

50 H. Locate the Spring/Knob Assembly Module, shown in figure 50. In the spring/knob assembly module, the part is clamped into place with a valve clamp. The robot positions the spring/knob assembly that it removed from the feeder and places it into an alignment groove on the assembly module s work surface. A pneumatic cylinder then extends to push the spring/knob assembly to contact the valve body. When the cylinder starts to extend, an electric motor on the opposite side of the valve body turns on. As the spring/knob assembly contacts the bolt, it pushes the bolt partly out of the valve body. The head of the bolt makes contact with a rubber tip mounted on the end of the motor shaft. This turns the bolt, which engages the threads into the knob. This will prevent the assembly from coming apart when it is moved to the next station. The motor turns off after a (programmed) time and the insertion cylinder retracts. The clamp cylinder retracts. The robot then picks up and orients the assembly and places it in a bin or into the next station, if attached. I. Locate the Electro-Pneumatic Valve Manifold, shown in figure 50. This valve manifold includes a 7-station manifold with six single-solenoid, 2-position DCV s, and one double-solenoid, 2-position detent DCV, all with manual overrides. J. Locate the Parts Set. The parts set includes eight 3-way valve spools, eight 4-way valve spools, eight manual operators (knobs), eight bolts, and eight return springs for use with this and subsequent stations. It adds to the parts sets supplied with stations 1 and 4. 50

51 7. Perform the following substeps to familiarize yourself with station 6, which is the model 87-MS6 Torquing station. This station tightens the screw in the knob to the correct torque. The part is then transferred to the end of the station on an electric belt-drive traverse. Once at the end of the traverse, the part is manually picked up by the next station s manipulator, if attached, and moved to the next station. SCREW TORQUE MODULE KNOB CLAMP MODULE ELECTRIC TRAVERSE MODULE ELECTRO- PNEUMATIC VALVE MANIFOLD Figure 51. Torquing Station A. Locate the Screw Torque Module, shown in figure 51. The screw torque module uses an electric motor with an adjustable clutch to torque the screw to the correct amount. The motor has a screwdriver attachment mounted on the shaft. A pulse width modulator allows the motor speed to be varied. B. Locate the Knob Clamp Module, shown in figure 51. The knob clamp module is located on the other side of the valve body. A pneumatic cylinder extends and a curvilinear gripper grips the valve knob. An inductive sensor detects when the part is gripped. The gripper holds the knob stationary while th e screw is tightened to the correct torque. C. Locate the Electric Traverse Module, shown in figure 51. The electric traverse module uses a synchronous belt drive powered by a reversible electric motor with a thermal overload and an adjustable clutch. The traverse has end-of-travel limit switches on each end. D. Locate the Electro-Pneumatic Valve Manifold, shown in figure 51. This valve manifold includes a 2-station manifold with two single-solenoid, 2-position DCV s with manual overrides. 51

52 8. Perform the following substeps to familiarize yourself with station 7, which is the model 87-MS7 Parts Storage station. This station uses a pneumatic manipulator to sort parts according to material and spool type. It has a divided gravity feed parts tray to hold the parts. A. Locate the Programmable Position Pneumatic Manipulator, shown in figure 52. The programmable position pneumatic manipulator uses a pneumatic rodless cylinder with a brake and infrared sensors for positioning. This manipulator uses a curvilinear 2-point gripper to remove parts from the previous station and sort them according to its program. The infrared sensors are used with tabs fastened onto the horizontal axis to sense location. PROGRAMMABLE POSITION PNEUMATIC MANIPULATOR ELECTRO- PNEUMATIC VALVE MANIFOLD 4 CHANNEL PARTS STORAGE MODULE Figure 52. Parts Storage Station B. Locate the 4-Channel Parts Storage Module, shown in figure 52. The parts storage module is sheet steel mounted at an angle and divided into four sections for the four different types of parts. C. Locate the Electro-Pneumatic Valve Manifold, shown in figure 52. This valve manifold includes a 3-station manifold with two single-solenoid, 2-position DCV s, and one double-solenoid, 2-position detent DCV, all with manual overrides. 52

53 9. Perform the following substeps to familiarize yourself with the components that are common to all stations. Each mobile workstation has an operator panel, controller, digital interface module, and pneumatic distribution module, as shown in figure 53, and electrical distribution module. DIGITAL INTERFACE MODULE PNEUMATIC DISTRIBUTION MODULE OPERATOR PANEL CONTROLLER Figure 53. Common Station Components 53

54 A. Locate the Operator Panel, shown in figure 54. Each operator panel includes a Start pushbutton and Output Power pushbutton. Each of these pushbuttons has a built-in lamp. These lamps are separately wired to the PLC. The PLC is typically programmed to turn on a lamp after its pushbutton is pressed. Also, you will find a Stop pushbutton, Auto/Manual/ Reset selector switch, and a Main Power (safety) switch. The main power switch has a location for an electrical lockout. Each panel also includes an Emergency Stop pushbutton that lights up when it is pushed in. AUTO/MANUAL/RESET SELECTOR SWITCH OUTPUT POWER PUSHBUTTON STOP PUSHBUTTON START PUSHBUTTON MAIN POWER SWITCH START LAMP (GREEN) EMERGENCY STOP PUSHBUTTON OUTPUT POWER LAMP (WHITE) Figure 54. Operator Panel 54

55 B. Locate the Controller, shown in figure 55. The controller is a Siemens S7300 series Programmable Controller, either model 313, 314, or 315. It also includes a portable PLC mounting console, 24VDC power supply, and a master control relay. MASTER CONTROL RELAY 24 VDC POWER SUPPLY PORTABLE MOUNTING CONSOLE CONTROLLER Figure 55. Controller 55

56 C. Locate the Pneumatic Distribution Module, shown in figure 56. The pneumatic distribution module includes the air regulator, pressure gauge, filter, and pneumatic lockout valve. AIR REGULATOR PRESSURE GAUGE PNEUMATIC LOCKOUT VALVE FILTER Figure 56. Pneumatic Distribution Module 56

57 D. Locate the Electrical Distribution Module, shown in figure 57. The electrical distribution module is located in the back of the station and includes the power distribution cable, power supply cable, electrical power outlets. POWER DISTRIBUTION CABLE ELECTRICAL POWER OUTLETS POWER SUPPLY CABLE Figure 57. Electrical Distribution Module (Shown from Rear of Station, looking up) 57

58 E. Locate the Digital Interface Module, shown in figure 58. The digital interface module includes terminal blocks with 72 input/output control terminals near the operator panel used for the wiring interface between the PLC and the automated components. It also includes terminal blocks with 72 separate terminal sets for power to I/O. DIGITAL INTERFACE MODULE Figure 58. Digital Interface Module 58

59 SEGMENT 2 SELF REVIEW 1. A machine sequence is a programmed series of or steps. 2. Each step of a control system sequence starts with an input signal, the then decides which output to turn on or off, then the machine step takes place. 3. To create a sequence of steps, the devices are physically arranged on the machine so completion of one step triggers the start of the next step. 4. Three types of pushbuttons are the extended button, head, and the flush button. 5. The four types of manual discrete output devices are indicator lamps, audible alarms, message displays, and. 6. A limit switch is an input switch that senses the position of a machine component by means. 7. An proximity sensor creates a magnetic field that is used to sense when a metal part comes into range. 8. A fiber optic sensor is a sensor that uses fiber optic filaments to send and receive the light. 9. A giant magnetoresistive sensor is a magnetic sensor that responds mainly to the magnetic field orientation and rather than the magnetic field strength. 10. Two types of automatic discrete output devices are directional control valves and. 59

60 SEGMENT 3 MECHATRONICS SAFETY OBJECTIVE 10 DESCRIBE EIGHT MECHATRONICS OPERATOR SAFE DRESS RULES Safety is the highest priority in all modern industrial plants. Companies strive to increase the productivity while at the same time ensuring that no one is injured. Jobs that involve mechatronics equipment can be very dangerous because there are fast moving parts through which high forces are often transmitted. The first line of defense against accidents with automation equipment is proper dress, as shown in figure 59. HEARING PROTECTION SAFETY GLASSES ROLLED SLEEVES HEAVY-DUTY BOOTS Figure 59. Safety Attire when Working with Running Machinery 60

61 The following rules will help ensure safety when working around industrial equipment. Most companies have specific safety rules that may vary from those given here. For example, some jobs may require that a person wear a long sleeve protective garment. Wear safety glasses Figure 60. Safety Glasses Wear hearing protection Avoid wearing loose fitting clothes Remove ties, watches, rings, and other jewelry Tie up long hair, put it under a cap or tuck it into a shirt Wear heavy-duty leather shoes, steel-toed shoes are recommended. Canvas shoes are not acceptable. Roll up long sleeves or wear short sleeves Do not wear gloves around machinery when it is running. Gloves can get caught in the moving components and pull a hand into the machine. Figure 61. Do Not Wear Gloves 61

62 OBJECTIVE 11 DESCRIBE EIGHT MECHATRONICS OPERATOR SAFETY RULES Mechatronics equipment can be very dangerous because it can change its position very quickly. Apply the following safety rules any time work is performed around mechatronics equipment. Do not enter a machine s area of operation until the machine is completely stopped. Perform a lockout/tagout on all power sources before starting a maintenance operation. Figure 62. Lockout/Tagout After locking out the system, remove any pressure (air or hydraulic) left in the system. Operating the DCV s manual overrides a few times should remove any remaining pressure. Properly secure a hose or device that contains compressed air. Fittings can blow out if they are not secure. Mechanically test or pull connections before pressurizing. Gradually increase the air pressure where possible while observing for loose lines or bad connection. Remove all obstructions from the work area. Check for signs of damage to equipment. Remove robot teach pendants from the work area. 62

63 Locate all emergency stop pushbuttons. Figure 63. Emergency Stop Pushbutton 63

64 OBJECTIVE 12 DESCRIBE THE OPERATION OF AN ELECTRICAL LOCKOUT/TAGOUT SYSTEM An electrical lockout/tagout system is a method of preventing all electrical power from being restored to a machine or workcell while work is being performed on it. An electrical lockout/tagout system has three main components: lock, lockout hasp, and a tag. The lockout hasp uses a scissors action to hook through the slots in a safety switch, as shown in figure 64. This prevents the power switch from being placed in the ON position. Once the hasp is fully closed, the holes in the bottom section are aligned. The lock is installed through one of these holes, also shown in figure 64, to prevent the removal of the hasp. Before the lock is closed, a tag is added to identify the lock s owner and the date the lockout was performed. POWER SWITCH MULTIPLE LOCKOUT HASP LOCK TAG Figure 64. Electrical Lockout/Tagout Every person working on a machine must install his or her own lock. The lockout device has holes for five locks. The sixth hole is used to install another lockout hasp to ensure that there are always available holes for additional locks. 64

65 SKILL 2 PERFORM A LOCKOUT/TAGOUT ON AN ELECTRICAL SYSTEM Procedure Overview In this procedure, you will perform a lockout/tagout procedure on the electrical disconnect safety switch of the 870 Mechatronics station. This procedure is the same for each mechatronics station, so this skill only needs to be performed on one station. 1. Check out a padlock, a lockout hasp, and a tagout tag, as shown in figure 65. This will be used to perform a lockout/tagout on the electrical system. Figure 65. Lockout/Tagout Devices 65

66 2. Perform the following substeps to perform a lockout/tagout on the 870 s electrical system. A. Go to one of the 870 stations and locate the safety switch on the front the Operator Panel, as shown in figure 66. SAFETY SWITCH Figure 66. Safety Switch for an 870 Station 66

67 B. Make sure the lever of the safety switch is in the Off position (down), as shown in figure 67. If it is not, place it in the off position by pressing down on the switch lever. (DOWN) OFF POSITION Figure 67. Safety Switch in the Off Position 67

68 C. Locate one lockout hasp and open it as shown in figure 68. Figure 68. Lockout Hasp Opened 68

69 D. Hook the lockout hasp through the slots in the switch bracket. Then, close the hasp, as shown in figure 69. Figure 69. Lockout Hasp Installed and Closed E. Fill in the appropriate information on the tag (your name, the class, and the date). If you have a lab partner, he/she should sign the tag also. Keep in mind that some instructors may require a tag for each individual person. F. Open your lock and hook it through the hole in the top of the tagout tag, as shown in figure 70. Figure 70. Lock Hooked Through the Tagout Tag 69

70 G. Install the lock and tagout tag on the lockout hasp, as shown in figure 71. If you are the only one who will be locking the device out, or if you are the first to install your lock, use one of the top holes of the lockout hasp. Others can use the remaining holes for their locks if they will be working on the device. The electrical safety switch is now locked out and tagged out. No one can operate the safety switch until the lockout and tag have been removed from the safety switch. Figure 71. Lockout/Tagout Installed on the Electrical Safety Switch 3. Have your instructor check your work to make sure the lockout/tagout is done properly. 4. Leave the lockout/tagout devices in place for the next skill unless your instructor advises you otherwise. 70

71 OBJECTIVE 13 DESCRIBE THE OPERATION OF A PNEUMATIC LOCKOUT/TAGOUT SYSTEM To ensure safety, all power sources must be locked out for service or maintenance. Pneumatic actuators can operate even though electrical power is locked out because the compressed air is still being provided to the system. Because of this, pneumatic systems are also often equipped with a lockout/tagout system. A pneumatic lockout/tagout has four main components: a lockout valve, lockout hasp, lock, and a tag. When the valve is in its closed position, the lockout hasp is placed through a slot in its lever. This prevents the valve from being shifted to its open position. The lock is installed through one of the holes in the lockout hasp, as shown in figure 72, to prevent the removal of the hasp. Before the lock is closed, a tag is added to identify the lock s owner and the date the lockout was performed. LOCKOUT VALVE INLET OUTLET HASP TAG LOCK Figure 72. Pneumatic Lockout/Tagout 71

72 The lockout valve is a two-position valve that allows flow through the valve in one position and blocks the supply line while venting the downstream air pressure in the other, as shown in figure 73. While the valve is being shifted from Closed to Open, air is supplied to the system and is also being vented, as shown in center of figure 73. This allows the slow build-up of pressure in the system to avoid damaging any downstream components. When fully open, the valve allows air to flow to the system, as shown on the right side of figure 73. CLOSED POSITION PARTIALLY OPEN OPEN POSITION LOCKOUT VALVE VENTING DOWNSTREAM PRESSURE SUPPLY BLOCKED FULL FLOW TO SYSTEM LOCKOUT VALVE LEVER PUSH PROVIDES SLOW INCREASE IN PRESSURE Figure 73. Lockout Valve Operation 72

73 SKILL 3 PERFORM A LOCKOUT/TAGOUT ON A PNEUMATIC SYSTEM Procedure Overview In this procedure, you will perform a lockout/tagout procedure on the pneumatic shut-off valve of the 870 Mechatronics station. This procedure is the same for each mechatronics station, so this skill only needs to be performed on one station. 1. Check out a padlock, a lockout hasp, and a tagout tag, as shown in figure 74. This will be used to perform a lockout/tagout on the pneumatic system. Figure 74. Lockout/Tagout Devices 73

74 2. Perform the following substeps to perform a lockout/tagout on the 870 s pneumatic system. A. Go to one of the 870 stations and locate the pneumatic lockout valve, shown in figure 75. PNEUMATIC LOCKOUT VALVE Figure 75. Lockout Valve for an 870 Station B. Make sure the lever on the lockout valve is in the Closed position (pushed forward), as shown in figure 76. If it is not, push the lever forward until the hole for the lockout lock is visible. CLOSED POSITION LOCKOUT HOLE Figure 76. Lockout Valve in the Closed Position 74

75 C. Install the lockout hasp through the slot in the center of the lever, as shown in figure 77. Figure 77. Lockout/Tagout Installed on the Pneumatic Locked Valve D. Fill out the tag with the appropriate information. E. Install the lock and tag to the lockout device. The lockout valve is now locked out and tagged out. No one can restore pneumatic pressure until the lockout and tag have been removed from the valve. 3. Have your instructor check your work to make sure the lockout/tagout is done properly. 4. Leave the lockout/tagout devices in place for the next skill unless your instructor advises you otherwise. 75

76 SEGMENT 3 SELF REVIEW 1. When working around automated machinery, it is important to wear vision and hearing protection, tie up long hair, and roll up. 2. When performing maintenance on a machine, every person working on the machine must install his or her own. 3. One of the most important safety rules to follow before performing maintenance on a machine is to perform a lockout/tagout on. 4. An electrical logout/tagout prevents electrical power from being while work is being performed. 5. Pneumatic actuators can still operate after power has been locked out. 6. A pneumatic lockout valve is a two-position valve that allows flow through the valve in one position and blocks the supply line while the downstream pressure in the other. 76

77 SEGMENT 4 MACHINE OPERATOR FUNCTIONS OBJECTIVE 14 DESCRIBE THE ROLE OF A MODERN AUTOMATED MACHINE OPERATOR Traditionally, the role of a machine operator has been to start and stop the machine, load parts, make adjustments to its settings, and monitor the machine. In the age of lean manufacturing, the operator s role in most automated facilities has become much more sophisticated, including functions such as using a computerbased operator terminal, performing quality assurance tasks, and performing basic machine maintenance. By performing these additional functions, operators have a much more valuable role. Figure 78. Operator Terminal 77

78 OBJECTIVE 15 DESCRIBE THE FUNCTION OF A BASIC OPERATOR PANEL The traditional operator panel uses discrete pushbuttons, selector switches, and indicators to help the operator monitor and control the machine s operation. The typical functions these operator panels may contain include: OPERATOR PANEL READY RUNNING FAULT STOPPED START CYCLE STOP HALT EMERGENCY STOP AUTO MANUAL JOG Figure 79. Operator Panel Machine Start A start pushbutton is often used to start the machine cycle. Typically, this is a green, flush, momentary contact pushbutton. Often the button will have a built-in indicator light that tells the operator at a glance that the machine cycle has been started. This light is turned on by a PLC output. It does not turn on by simply pressing the pushbutton. Machine Cycle Stop A cycle stop pushbutton is used to stop the machine at the end of its current sequence. This is considered a normal stop because all actuators return to their start positions and pressing the start button will begin the sequence again. The cycle stop is used to stop the machine in the event of a break, end of shift, or if the operator is out of parts. A red, extended, or flush, momentary contact pushbutton is commonly used for the cycle stop function. It is not intended for use as an emergency stop. The National Electrical Manufacturers Association standard ICS 5 requires that any pushbutton that performs a stop function must be red. 78

79 Emergency Stop Every operator panel should include an emergency stop pushbutton that will remove power as quickly as possible. This button must be a red, maintained-contact type and is typically a large, mushroom-shaped button that can be hit quickly. Often, the button is illuminated so the operator can tell at a glance that the button is engaged. Manual/Automatic Almost all automatic machines have the ability to operate in either a manual or automatic mode. On a traditional operator panel, a selector switch controls this function. Some mode selector switches are two-position with automatic and manual modes, while some are 3-position types with either an off function or a reset function in addition to the automatic or manual modes. Jog The process of operating one of the machine s actuators in the manual mode is called jogging. Jogging is most often performed by operating a pushbutton or selector switch on the operator panel. This causes the actuator to move in one direction while a pushbutton or selector switch on the operator station is actuated. The jog function also can be performed using manual overrides on devices such as fluid power valves or motor starters. In many machines the manual mode is programmed into the PLC that controls the machine. It is activated by placing a selector switch on the operator station in the manual position while the PLC is on and in the RUN mode. The PLC ladder logic assigns pushbutton inputs to control outputs that jog the machine s actuators. The manual portion of the PLC program is written so that any sensors that may be triggered while the actuators are jogged do not affect the PLC s operation. Halt Many operator panels include a Halt pushbutton. The halt function is used to stop the sequence of an automated machine after the current step. All power remains on and the start pushbutton will resume the sequence provided all inputs remain unchanged. This function is often included in equipment where the operator may need to pause the cycle for some reason. Activating the halt function is usually done through the use of a red, extended, momentary-contact pushbutton. 79

80 Indicator Lights Indicator lamps are used on an operator panel to tell the operator at a glance the status of the machine. Depending upon the purpose of the indicator lamp, it may be programmed to be on the entire time it is active or blink to catch the eye of the operator. There are a many lens colors available for indicator lamps. Each color represents a different status, as shown in the following table. LENS COLOR TYPICAL FUNCTION EXAMPLE Red Danger, Abnormal Condition, Fault Condition Voltage applied; cycle in automatic; faults in air, water, lubrication or fi ltering systems; ground detector circuits. Amber (Yellow) Attention Motors running; machine in cycle; unit or head in forward position. Green Safe Condition (security) End of cycle; ready for cycle; cycle running; unit or head returned; motors stopped; motion stopped; contactors open. White or Clear Normal Condition Normal pressure of air, water, lubrication. Figure 80. Indicator Lens Color Functions 80

81 OBJECTIVE 16 DESCRIBE THE OPERATION OF THREE CATEGORIES OF STOP FUNCTIONS A global standard exists that defines the methods used to safely stop machines for various applications. This standard has three categories, which include: Stop Category 0 - This stop category immediately removes power to the machine actuators. It is an uncontrolled stop because no power is available to brake the actuators. The motors will spin freely and coast to a stop over a period of time. A category 0 stop is higher in priority than category 1 or 2 stop functions. Stop Category 0, which is often used as an emergency stop must be initiated by one human action and must override all other machine functions and operating modes. Typically, the output power is removed using a master control relay. Stop Category 1 - A category 1 stop is a controlled stop, which means that power is available to the machine actuators to brake to a full stop. Power is then removed after the stop is achieved. Stop Category 2 - A category 2 stop is controlled stop with power left available to the machine actuators. This is considered a normal production cycle stop or halt function. This stop category stops at the end of the current movement or current cycle depending on its programming. CYCLE STOP (CATEGORY 2) COMPONENT STOP EMERGENCY STOP (CATEGORY 0) Figure 81. Stop Functions 81

82 OBJECTIVE 17 DESCRIBE HOW TO OPERATE AN AUTOMATED MACHINE Automated machines vary by design and operation, but there are a number of operation steps that are typical of most machines. The following is a general guideline to starting up, operating, and shutting down automated machines. Always review the operator instructions for a specific machine before operating it. Step 1: Perform Safety Checks Before applying power to any machine, certain safety issues must be addressed. The work area must be clear of personnel and obstructions, which includes looking the equipment over to make sure there are no tools or maintenance components such as chocks or supports left in a work area. Check for fluid leaks that can indicate a problem with the equipment and/or create a slipping hazard. If any equipment panels are left open, check with maintenance to verify the equipment has been tested and is ready to run. Verify that all safety guards are in place. Step 2: Prepare Machine for Startup This step may involve stocking parts in feeders, using the mode selector switch to put the equipment in manual mode so it does not start up when power is applied, or checking/replacing tooling. Step 3: Remove Lockout/Tagout Devices Remove any lockout/tagout devices on electrical, pneumatic, hydraulic, or mechanical power sources. HASP Figure 82. Lockout/Tagout Devices 82

83 Step 4: Power Up the Machine This step involves turning on all power to the equipment and may include: Turn on the main power switch or electrical disconnect - The main power switch is normally located on the operator panel while a disconnect switch may be mounted in a nearby location. Turn on air and/or water - The air supply is restored using either an air regulator or shutoff valve and the water supply typically uses a shutoff valve. Turn on hydraulic power supply - Hydraulic power is supplied by a hydraulic pump driven by a prime mover such as an electric motor. Check the hydraulic fluid level in the reservoir to verify that it meets operating requirements and then start the pump. Check/set pressures on air/water/hydraulic - Check the fluid pressure and set to operating levels. Air uses a regulator for pressure adjustments. Water is typically regulated with a valve, such as a globe or gate valve or it may have a regulator. Hydraulic pressure is controlled through a relief valve or pump compensator. Step 5: Turn on PLC Output Power Verify that the PLC s modules are powered up. They often have a separate power switch or pushbutton that controls the output power. Step 6: Home or Reset All Machine Actuators and Robots This step sets each actuator back to the home position and makes sure the machine is ready for start up. This is often done with a reset selector switch or with individual actuator reset pushbuttons on the operator panel. Robots are put into run mode at this time. 83

84 Step 7: Place System in Auto Mode Put the system in Auto mode for operation. Typically this is done with a selector switch on the operator panel. POWER SYSTEM PRESSURE READY CYCLE ACTIVE REVERSE (DEACTIVATE) FORWARD (ACTIVATE) 3 LOAD SELECTION LOAD CONTROL BRAKE CONTROL 1 IDLE AUTO MANUAL CYCLE SELECTOR SWITCH CYCLE START CYCLE STOP PROGRAM CYCLE Figure 83. Power Up the Machine Step 8: Start Operation Operation of automated equipment usually starts when the operator presses the start pushbutton. Although the equipment is automated, an operator is typically nearby to reload part feeders, clear part jams, and observe operation. 84

85 Step 9: Stopping the Machine Typically, there are three planned-for types of stop functions that can be programmed into a machine: halt, cycle stop, and emergency stop. Most machines have two or three of these functions. The halt stop function stops the equipment at the end of the current movement without removing power. This pushbutton can be pressed any time during the cycle. This function is used to temporarily pause operation for some non-emergency reason. Halt functions are typically programmed so that pushing the start pushbutton again resumes the program where it left off. The cycle stop function, once initiated, stops the equipment once the current cycle finishes. This pushbutton can be pressed at any time during the cycle. This function is used to stop the cycle for a break or at the end of shift because it stops the equipment in its home position, ready for the next cycle. Power is still on and typically the cycle can be started again once the start pushbutton is pushed. The emergency stop function removes all electrical power immediately to the machine s actuators. This typically reinitiates all programs in memory as well. This function is used when damage to the equipment or personal injury is likely to occur. When the cause for pressing the emergency pushbutton has been cleared, the emergency pushbutton is pulled out, power is restored to outputs, all machines are reset, homed, and the cycle restarted by pressing the start pushbutton. A power loss during the middle of a cycle acts much like an emergency stop. After power is restored, all equipment must be reset, homed, programs reinitiated, and the cycle restarted by pressing the start pushbutton. Parts may have to be removed from the equipment so that a new cycle can be started. There are times that a power outage may cause some unforeseen problems with the equipment, so it is always a good idea once power is restored to test the equipment and program without parts or to test it manually to make sure that it runs as designed. Step 10: Shutdown Once the system is stopped at the end of the cycle, the shutdown procedure can be performed. This includes: Shutting down any computers Turning off all power supplies to the equipment (air, water, electric, hydraulic) Performing lockout/tagout procedures on all power supplies. 85

86 SKILL 4 POWER UP AN AUTOMATED MACHINE Procedure Overvide In this procedure, you will perform a power up and power down sequence on the 870 Mechatronics Station. This procedure is the same for each mechatronics station, so this skill only needs to be performed on one station. The power up sequence includes steps 1-5 of the startup sequence presented in the previous objective. 1. Locate a Mechatronics 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 station from the other stations. A. Verify that the station power cord has been removed from the wall outlet. B. Remove the adjoining station s power cord at the back of the station. ADJOINING STATION'S POWER CORD STATION POWER CORD Figure 84. Adjoining Power Cord Removed (Shown from Rear of StationA) 86

87 C. Remove the adjoining station s pneumatic hose. ADJOINING STATION'S PNEUMATIC HOSE Figure 85. Pneumatic Hose (Shown from Rear of Station) D. Disconnect 9-pin to 9-pin cable from the station. 9-PIN CABLE Figure Pin Cable 87

88 E. Loosen the connecting fasteners that hold the work surfaces together by turning the thumbscrews CCW. TURN CCW Figure 87. Connecting Fasteners F. Remove the thumbscrew and set aside. G. Push the station away from the other stations to give yourself room to work. 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 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 area Ensure that all people are outside any work envelopes Figure 88. Mechatronics Safety Check 88

89 5. Connect an air supply to the air manifold s quick connect in the back of the station as shown in figure 89. COMPRESSED AIR SUPPLY STATION AIR HOSE Figure 89. Station Air Hose Attached to Compressed Air Supply 89

90 6. Plug the station s electrical cord into a power outlet. If the power cord is not attached to the station, locate it in the back of the station and plug the female end into the station s power plug under the work surface at the back of the station, as shown in figure 90. Then plug the other end into the wall outlet. There will be no visual indication that power has been applied to the station. Plugging the power cord into the outlet brings power to the back of the station. STATION S POWER PLUG STATION POWER CORD Figure 90. Station Power Cord Attached to Wall Outlet 7. Place the mode selector switch in the Manual mode setting by turning the selector switch. Figure 91. Mode Selector Switch Set to Manual Mode 90

91 8. Remove the lockout/tagout device from the electrical power source. 9. Remove the lockout/tagout device from the pneumatic power source. 10. Turn on the air to the station by shifting the lever on the lockout valve. 11. Turn on the Main Power switch. Allow the PLC a couple of minutes to go through its boot sequence. You should see the following PLC indicator lights turn on: Run or Stop - depends on the placement of the PLC switch PLC input power (DC5V) Various PLC inputs, depending on the station There will be no control panel indicator lights active at this time. INPUT INDICATORS PLC INDICATORS Figure 92. Station Indicators 12. Push the Output Power button On. This will activate power to the outputs on the station s PLC. You should hear the contactor next to the PLC modules pull in, indicating that output power is now on. 91

92 13. Verify that the following indicator lights are on: Output Power button Various PLC outputs The Start pushbutton indicator will be off if the station is ready for operation. If the actuators are not in the home or reset position, the indicator will be blinking until the actuators are reset. OUTPUT INDICATORS Figure 93. Output Indicators 14. Perform the following substeps to review the pneumatic connections on the station shown in figure 94. FEMALE CONNECTION SHUT OFF VALVE WITH LOCKOUT AIR FILTER PRESSURE GAUGE SHUT OFF RELIEVING REGULATOR TO COMPONENTS BRANCH LINE MALE CONNECTION Figure 94. Pneumatic Connections 92