Pneumatic Controller

[Kinsrow]

Hello,
I have a linear slide coupled to an air cylinder. I need to cycle a test sample back and forth for 50,000 cycles using this setup. I was thinking of using timer to tell the air cylinder when to stop

I think I'm going to need a valve, a timer, air regulator, air flow control, on/off button. This seems to be pretty straight forward but i'm having hard time to put it all together.

Thanks

 

[MintJulep]

I'd use a limit switch or proximity sensor at each end and a counter to stop when you're done.

A timer would be difficult to implement in a robust way.

 

[Kinsrow]

OK, I can do that too.

Do you have any diagram you can share that explain what goes to what?

Thanks

 

[IceStationZebra]

I have done many similar set-ups in the past.
- I run 2 regulators in series. The first one drops the supply down below the lowest seen on the supply line. (i.e. - if the shop supply ranges from 95-110psi, set the 1st regulator to 90psi or lower) Use the 2nd regulator to tune your cylinder pressure/force. This prevents the normal changes in supply pressure from changing your cycle time.
- Use flow control valves to tune the speeds. Get one-way versions so you can tune both directions independently. I usually regulate the inlet flow but you might want to regulate the exhaust flow if you have a part that sticks, otherwise it can build pressure than shoot out.
- You can use a timer, but a limit/prox switch will get the test done quicker. With a timer you need to allow a little extra time to make sure you have reached the end of stroke, where the switch does it automatically. Those extra seconds can add up.
- Try not use the timer or limit/prox switch to increment your cycle counter. If something breaks you will still be incrementing counts, meaning you won't know when it broke. You need to find a method of counting cycles that will stop when your specimen breaks.
- I would recommend a small PLC for $100-150 USD. Most have multiple inputs allowing you to rig up both direction switching and error detection inputs.
- You can get little standalone timers from several sources. One option...

http://www.omron247.com/Industrial-...ents+Timers+Digital&isBL=2&technologyId=22711

ISZ

 

[itsmoked]

A lps ISZ for the nice tips.

Might I also suggest these programmable relays which are pretty much the same as the Omrons. They just cost less and the software is a tiny bit clunkier. However you can download the SW for free immediately, write your program, and simulate it, before even, buying anything.

http://www.factorymation.com/s.nl/sc.2/category.22/.f

Keith Cress
kcress -

http://www.flaminsystems.com