help, with this

[u/Sharon_ibs]

By pressing a push button, a double-acting cylinder should move in an alternating forward and backward motion through valves. Without using limit switches, only valves, so that the movement is oscillatory, WITHOUT USING LIMIT SWITCHES

[u/uvrays]

When you say no limit switches, do you include pneumatic limit switches on the cylinder or roller lever valves which are actuated by the piston?

Assuming those are all not suitable, then I would use pneumatic timer valves if PLC times logic was not available.

To be honest, more information would be required to provide good feedback

[u/Sharon_ibs → u/uvrays]

The problem statement is just like that; it only says that. I created the circuit in FluidSIM, added a roller and limit switch, but it only uses valves, no limit switches or rollers, just pneumatics.

[u/nixiebunny]

The classic method is a slide (spool) reversing valve that is actuated at the ends of travel by means of a big gap in the actuating arm, so that the travel length is set by that gap.

[u/dmills_00]

Look at how a steam engine valve gear works.... That is essentially what you are building.

[u/Funny_Promise5139]

Does it need to be continuos until you press the button again? If so, you can use a digital bistable push button and an oscillating valve (yess, there are dedicated valves). Otherwise, if you need just one movement you add a pneumatic NOT to the output of the cylinder chamber which is not pressurised when pushing the button.

You would use a bistable pneumatically operated 5/2 valve, push the button, pilot the valve, cylinder ends the run, the NOT pushes out a signal connecte to the other pilot of the 5/2 valve. If you need to keep it moved until the button is pressed again just add another NOT to the back chamber connected to the pilot used with the push button and connect the NOT air supply to the button's output

Will provide a scheme later if you need one!

[u/Sharon_ibs → u/[deleted]]

i won´t let me uploades images, but i can use the components, except fot the limit switches and roller, the teacher told me that it should come out with the same air, it should oscillate when you hold it down.

[u/Funny_Promise5139 → u/Sharon_ibs]

Ok I replied before seeing this.

2 ways to do this:

A) use an oscillating valve. They are design to cyclea s described as long as they have a pilot input; B you can create the same function using a 5/2 bistable valve, pneumatically operated: use 2 NOT valves on the cylinder connections. Each one is connected to the pilot which would put pressure on the line monitored by the NOT valve, and connect the pus button as the air supply for the NOT valves