fully pneumatic machine problem

[Alex37]

Good morning to all,
we are doing maintenance to a department, and we have dismantled the machines to paint them with the occasion, now after having reassembled and tried them I agree to something strange, I press that are very simple, they have only two actuators, but they have a complex system of pneumatic valves.
on an actuator we use on both quick discharge inputs with silencer.
now when the machine finishes the cycle, after a few seconds, it feels that it starts to download the air from the silencer.
the resting actuator is not fed continuously with the air, it is only given a command for a couple of seconds and then stops, in this way having no more air in the air inside the actuator exits for the rapid discharge.
Is it normal that the actuator is not continually commanded at rest?
Thank you all.

 

[meccanicamg]

I would say that it seems a strange thing to me that you describe me. Surely those who did the plant originally did not have much practice with tire systems. . Or what you describe to me is wrong or you mounted wrong.

as I understood you have:
- pneumatic cylinder
- t connection on both vents
- on a t exit you have the silencer
- on the other exit of the t you have the air pipe

If so it is normal that if you excite the valve air passes and partially discharges from the silencer and more than once does not push the cylinder. if you keep it excited, empty the compressor.

Anyway, I think I'm a minkey. it was enough to mount the electrovalve to open centers that by itself discharges if not excited, make the call for cylinder to rest and then disecciti and the air comes out from the valve (not from the mouth). I think that's how it is mounted even if as you explain it you seem the first explanation.
if you use it at closed centers, not exciting the valve remains in pressure.

Alternatively if it is not a 3-position valve will be at 2 but nothing changes.

 

[cacciatorino]

Is it normal that the actuator is not continually commanded at rest?
Thank you all.

normally It's like you say, I mean, actuators always have a pressure chamber and the other one running. but there are rare cases where they are left free (with so-called "open" valves) when they have performed their function. You should make sure it's not one of these cases.

 

[Alex37]

but if it were at open centers, and so it is normal that you don't get air to the resting cylinder, there's no way you don't get the air out of the rapid discharge before you did it?

 

[meccanicamg]

but if it were at open centers, and so it is normal that you don't get air to the resting cylinder, there's no way you don't get the air out of the rapid discharge before you did it?

Is it not that he had an excitation/unloading valve before? so pneumatically driven valve?

 

[Alex37]

we have detached all the valve group without disconnecting anything, we have detached only the rods from the various micro and cylinders, I hate these machines all air, drink electricity. . .
cmq the valve that controls the cylinder is not continuously excited only comes with impulses for this the cylinder has this problem, if I don't remember badly even before the maintenance the cylinder was not controlled at rest, but did not do this strange discharge of air at rest. . .

 

[cacciatorino]

we have detached all the valve group without disconnecting anything, we have detached only the rods from the various micro and cylinders, I hate these machines all air, drink electricity. . .
cmq the valve that controls the cylinder is not continuously excited only comes with impulses for this the cylinder has this problem, if I don't remember badly even before the maintenance the cylinder was not controlled at rest, but did not do this strange discharge of air at rest. . .

I don't understand. When you say that the valve is not excited continuously but with impulses, you mean that removing the current the air stops flowing, or that the valve remains in position as last command received? In this second case, it is a very common bistable valve, where the coils are excited only for the short time necessary to switch the state. I think you've been wrong to reassemble something, it might be the frl group too choked.

 

[Alex37]

the cylinder is not controlled by an electrovalve but by several pneumatic valves, I don't understand why the pulse has to pass through a series of valves with flow throttles before going to command the valve that controls the cylinder.
the most recent machines are electrified a unique simplicity.. .

 

[Er Presidente]

ma una foto?

 

[Alex37]

solved, there was a fitting on a valve that lost and dumped the cylinder.
thanks to all for the advice.