Hydraulic Solenoids

This company keeps popping up. I don't know if there is something you can add to your existing set up to dampen the shock.

http://www.hydraulicspneumatics.com.au/products/reduce-shock-with-solenoid-soft-shift-option

Well, yes, there are such things as hydraulic snubbers that can be added to circuits, and, as kramarat has cited a specific company, designs for the spools of hydraulic valves (and solenoids) with things like tapered sections to minimize shock.

But, my question is--is this a new machine or an older machine--if older, has it always worked this way? If not, I suspect a maintenance problem rather than a design problem.

If it's always worked this way (and/or new) it sounds like a design problem.

Hi Normbourne,

Both Kamarat and rhkramer have made Good Answers.

The hydraulic shock is obviously caused by the speed of operation of the solenoid valve and as previously suggested, needs to be controlled but depending on the machine and the actual function, slowing down the operation to reduce the shock might have consequences in the machine cycle.

It would help (and be interesting) if there was more information on the actual machine.

Take care, I'm sure with a bit more information there is plenty of help out there in CR4 land.

Best regards

John

Is it actually the solenoid, or could you be seeing what is commonly referred to as "water hammer"? Possibly the system was not properly designed as already stated, and needs a small accumulator to dampen the pressure spikes. More information would be needed.

The machine is home built and handles the output of a concrete block making machine. It has been in operation for some years, and this problem has been apparent since it's construction, but of course with subsequent wear on the various linkages, it has become more apparent. Indeed, I think it has contributed to the wear. Yes I think it is the equivalent of water hammer.

Norm.

What about a pressure compensated flow control valve?

I used to work on tortilla presses that ran 1800psi 20 strokes per minute

the flow control would change the characteristics during direction changes

this was especially important during the return stroke

I also agree. I have an application where hydraulic accumulator is used in a single flap non-return valve installed at discharge of a large centrifugal compressor to absorb the impact load while sudden closing & hitting its metal seated surface.

Hi,

The answer is yes but you do not say what flow or pressure you are working at or give any indication of frequency of switching. All the major and plenty of the minor manufacturers have solutions to too rapid switching. The easy way today would be to use a proportional solenoid valve. Talk to any of the majors and they will solve your problem.

You may also need to look at the mechanical side of the machine as the machine structure could be ampliflying the problem.

Oliver Dunthorne