IMTS 2012 Valve Control

Transcription

1 Pneumatic Control Mechanical Control IMTS 2012 Valve Control Ryan Hettinger Applications Engineer Festo Corporation Solenoid Control Fieldbus Control Integrated PLC Control

2 IMTS 2012 Pneumatic Control Pneumatic Operators: Inherently Safe Intrinsically Safe Explosion Proof Cost effective for low volume automation Allows for pneumatic logic instead of more complex field-bus systems

3 IMTS 2012 Pneumatic Control - Pneumatically Actuated Valves 3

4 IMTS 2012 Pneumatic Control - Pneumatic Logic Gates AND Gates OR Gates 4

5 IMTS 2012 Pneumatic Control Advanced Function Operators Impulse Valves Time Delay Valves

6 IMTS 2012 Mechanical Control Ideal components for simple automation Minimal steps per process Interface for both human and physical component interaction with automation process Mechanical Limits Low-cost process industry valves, presses, low volume manufacturers 6

7 IMTS 2012 Mechanical Control Stem Valves Actuated once a load or force overcomes the resistance of the internal spring, depressing the stem Base design for many other types of mechanically and manually operated valves Does not require electricity to operate Intrinsically safe Explosion proof 7

8 IMTS 2012 Mechanical Control - Various Actuators Pin-type Cantilever Valve Roller Lever Ball actuated Whisker Manual Actuators 8

9 IMTS Mechanical Control - Manually Actuated Valves Hand Lever Toggle Push Button Finger Lever 9

10 IMTS Mechanical Control - Manually Actuated Valves - Examples Two Hand Control Operator safety Press/Process will not begin without both push buttons pressed Guarantee operator s hands are not in harms way 10

11 IMTS Mechanical Control - Manually Actuated Valves - Examples Control Cabinet Integration Emergency Cut-off Manual On/Off valve to feed system 11

12 IMTS Mechanical Control Valves with Idle Return Idle Return Stem valve with spring loaded roller lever Roller leaver will only actuate in one direction Roller mechanism would spring back after return stroke 12

13 IMTS 2012 Solenoid Control Direct Acting Solenoid Pilot 13

14 IMTS 2012 Direct Acting Solenoid Solenoid Pilot 14

15 IMTS 2012 Solenoid Piloted Valve Internal pilot air Drive chamber 15

16 IMTS 2012 Solenoid Piloted Valve External pilot air Drive chamber 16

17 IMTS 2012 Current Reduction Circuits i i t t 17

18 IMTS 2012 High Speed Valve Control MH.. - M1H - MH.. - MS1H - MS coil Electronics inside Power supply 48 V DC or more Voltage Reg 48VDC /24VDC Control unit (PLC) 18

19 IMTS 2012 High Speed Valve Control Charge capacitor Peak drops at constant cycling! Controlled coil current 1 A Drop to first hold current Second hold current Current in coil Current at connector 19

20 IMTS 2012 Connection of Solenoid Valves Once you have selected the use of solenoid valves, you must adopt a scheme to control them. We will explore 3 common methods: Conventional Systems with individual coil connections Multipin Valve Terminals with a single, multipin connection Fieldbus Valve Terminal, with a network connection 20

21 IMTS 2012 Connection of Solenoid Valves Use the following Packaging machine example: 6 stations each with 8 cylinders 6 single acting cylinders, 2 double acting cylinders 2 sensors each cylinder Total : 96 In / 60 Out Electrical Control Box connection points per station : 87 Electrical Terminal box connection points per station : 137 Pneumatic connection points per station : 64 Total connection points: per station = 288 per Packaging machine =

22 IMTS 2012 Conventional Connection of Solenoid Valves Advantages: Familiarity (it s the way we have been doing it) Disadvantages : Time and cost-intensive Material costs Error prone Larger installation space No additional information Applications : Most factory or process installations Note: as I/O increases, costs increase linearly 22

23 IMTS 2012 Multipin Connection of Solenoid Valves Migrate to a Multipin solution Use a multiwire cable to connect the valve terminal to a controller. Share commons Share pneumatic supplies & exhaust Advantages: Reduce time to install, material costs, space, chances for errors Disadvantages : No additional information Applications: Ideal for compact machines / short cable runs 23

24 IMTS 2012 Fieldbus Connection of Solenoid Valves Migrate to a Fieldbus solution Use a network adapter to convert digital signals from a controller on a bus to actions on a valve terminal. Replace most connections with network Share pneumatic supplies & exhaust Advantages: Further reduce time to install, material costs, space, chances for errors Add diagnostic or parameter information Increase distances & capacity Disadvantages : Education on new equipment Applications: Ideal for complex systems requiring a variety of I/O types 24

25 IMTS 2012 Integrated PLC with Solenoid Valves Independent control or Intelligent slave solution Embed a PLC directly into a valve terminal. Eliminate most connections. Eliminate large control box for PLC Share pneumatic supplies & exhaust Advantages: Absolute minimum installation time, material costs, space, chances for errors Included diagnostic and parameter information Integrated networks for additional I/O, HMI s Disadvantages : Need to gain experience on on new equipment, but similar programming environment like ladder logic included Applications: Ideal for small / medium machines Autonomous work cell of much larger machine 25