Any Suggestion

[guptara]

Simple situation:

I am operating a horizontal cylinder with a 4/3 Solenoid directional control valve. The cylinder is used to open (when retracting) or Close (when extending) a gate.

In the event of a power failure, i want the gate to be closed. But what if the cylinder was halfway through opening thye gate abd power goes off. The cylinder will hold its position.

Apart from using an accumulator, any other suggestion to ensure the closing of gate in emergency or power failure ??


Thanks in Advance.

 

[maytag]

You didn't say whether the gate only has to maintain 2 position-100%open and 100 %closed? the only thing that comes to mind quickly is to bias the gate mechanically-a heavy weight hung from a wire rope and using a sheave or block would work as long as it was heavy enough to close the gate and you used either a float center spool DCV or if only the 2 positions fully open and fully closed are needed then use a 2 position DCV and hook your cylinder lines up so that in normal(deenergized) position the rod end is connected to tank. Maytag PS I'm assuming that the power source for your pump is also feeding the DCV

 

[budt]

What maytag suggest's or some heavy duty springs would do the job, but, remember the energy has to come from somewhere and to use a mechanical method you will have to at least double the pressure on the retract stroke of the present cylinder or double the cylinder retract area and use a higher flow pump if you want to maintain speed. In either case the present hydraulic unit will only have half power or speed at best.

What is the resistance to using an accumulator? I designed and installed an accumulator circuit exactly like this and it worked great


Bud Trinkel CFPE
HYDRA-PNEU CONSULTING, INC.
fluidpower1 @ hotmail.com

http://www.fluidpower1.us