One port connects to the compressor tank, one to the piston cylinder, and the third is the vent.
In position 1, the port to the compressor is closed, and the cylinder port is vented. In position 2, the cylinder port is connected to the compressor.
The cylinder has two ports - if one is high-pressure and the other is vented, it pushes out, reverse and it pushes in. Put high-pressure on both ends and it locks in place, vent both ends and it moves freely.
I'm thinking about using them in a ball socket joint part of my project. How would i do something with the control scheme so that it sends how many centimeters the piston should go out or go in?-signol01
Hi Air is only good for basic tasks, and more bother than it is worth. I would look into some kind of motor controlled actuation. If you could provide some more detail on the application, i might be able to give some alternative ideas.
I am trying to devise a control scheme to control the position of a rod connected to another through a studded rod end. I figured I would need atleast 2 cylinders to facilitate lateral and medial movement. Also what about these solenoid valves?-signol01
I think i have a handle on what the operation is, i take it you are using the rod end as a pivot for another rod passing through the ball end? Getting back to pneumatics, it is extremely difficult to get get an air cylinder to move a precise amount. Air cylinders are really meant to move the full stroke, or until the regulated pressure is exceeded. It can be done with hydraulics, but that is a totally different beast, and takes some expensive and complicated control to achieve it. I am not saying that is is impossible, but would not be worth the effort for the end result. Plus the whole air system is a problem, you need an air source, compressors are noisy and run hot, water accumulates in the lines, oil lubrication needs to be added to the air, valves lock up, etc. And since it is an open loop system, encoders would be needed for positioning. I don't know what kind of travel distance you are looking at, so that can be a problem too, the cylinders tend to get pretty big when you get over a couple of inches. A possible alternative is a motorized linear actuator, usually propelled by a stepper motor like this ultramotion.com/products/digit.php.
There are other types, with dc motors and encoders built in, depends on your budget. You could also build your own, using step motors and lead screws, same idea as a X / Y positioning table. The emphasis has been based on rotary positioning over linear, so there is not a lot of options.
Comments
Pneumatic Cylinder Actuator
A 3/2 valve has three ports and two positions.
One port connects to the compressor tank, one to the piston cylinder, and the third is the vent.
In position 1, the port to the compressor is closed, and the cylinder port is vented. In position 2, the cylinder port is connected to the compressor.
The cylinder has two ports - if one is high-pressure and the other is vented, it pushes out, reverse and it pushes in. Put high-pressure on both ends and it locks in place, vent both ends and it moves freely.
(i.e., you need to valves to run each cylinder.)
kelvin
There are other types, with dc motors and encoders built in, depends on your budget. You could also build your own, using step motors and lead screws, same idea as a X / Y positioning table. The emphasis has been based on rotary positioning over linear, so there is not a lot of options.
kelvin