Syncing Two Air Hydraulic Cylinders

[KIDTech]

Does anyone have any insight on this? I am trying to use one airline to control two of the HF 20 ton air hydraulic cylinders instead of using seperate air lines. I thought about just making a foot pedal that would press both of the hand triggers but that would still require two air lines. Any help would be greatly appreciated if you have ever done anything like this and even if not but know how to get it done.

[steel 35]

My first attempt would be one hand control and two equal lines from it too the cylinders. If that dosent work send me one of the air over cylinders and I will send my hand cranker.

[Shane Warnick]

If you are using straight air cylinders, then you should be able to have the valve that activates the cylinder, then just downstream place a T in the line, and run one to each cylinder. The pressure should equalize between the two cylinders and then apply equal force to each. Probably NOT something I would just cut the airline and place a T in with some hose clamps on, as if you get 150 psi on there, with all the air in the cylinder and a load on it, and one comes off, it will most likely beat anything within reach damn near to death, you included. I would prob use hard lines for that, maybe stainless tubing or something.

Unless, if you are actually using Air OVER hydraulic cylinders, in which the air is actually driving the pump mechanism for the hydraulic side, and the cylinders are actually hydraulic cylinders, not pneumatic cylinders. If that is the case, the only way I can think of that you can sync them, is to use ONE air actuator, to run ONE hydraulic pump. You will obviously need a bigger reservoir, and you will need to place a T on the discharge side of the hydraulic side, and again, a line to each cylinder. It will, however, more than likely be slower than christmas, as you have effectively cut the output of the hydraulic pump in half. It still puts out the same amount of fluid per stroke, but you are now splitting it between two cylinders, not one. You will also have to plumb the return lines back into the reservoir, so when you release the cylinders the fluid can get back to the reservoir.

If you are using Air over Hydraulic, without joining them to one pump, I doubt you can ever get them to truly sync, one will always run a little faster or more efficiently than the other, and the pressure will never be exactly the same between the two cylinders.

Shane

[srp]

Adjustable flow valves on ea cylinder?

[Black Forest]

In order to sync them you need to give us more information. What application? How far apart will they be mounted? Will the loads on each cylinder be equal? Will the loads on either/or vary during the cycle?

[KIDTech]

It is for a 40" Swag press brake, I will get a picture tonight or tomorrow.