Integrated Pressure/Force Sensor in Hydraulic Cylinder

[eric.s]

Hi All,

I am new to hydraulics. I recently graduated with a mechanical engineering degree and no classes in fluid power and very little hydraulic experience. I am trying to understand why there are no commercial hydraulic cylinders that can either measure the force at the rod end or the internal pressure in the cylinder. I have machine the becomes unaligned every now and then and crashes out. Knowing either of the two values would let me send a signal to my PLC and stop the cylinder from damaging itself or the machine when it is in that unaligned state. I feel like I am missing something because it seems like this should be fairly straightforward to implement.

Thanks

 

[Compositepro]

It is very simple to put a pressure sensor on a cylinder. It is not the best way to solve an alignment problem, however.

 

[hydtools]

I would say every instrumentation person has their favorite brand of transducer. A generic transducer supplied with a cylinder may not have the specific characteristics any one customer wants. It would be cumbersome for cylinder manufacturers to be able to satisfy every need.

You need to find and solve the root cause for the misalignment.

Ted

 

[eric.s]

Thank you for your replies they did help me find my error in thinking! I was having a mind lapse thinking that pressure transducer was not what it actually is. Unfortunately the root cause of the misalignment is known, age and wear (25+ year old specialty machine) so right the now the best solution is to prevent the damage from the misalignment because a permanent fix is too expensive.

 

[IRstuff]

One obvious path, whether feasible or not, is to try and determine either the wear level or degree of misalignment over time. Certainly, wear can be manifested as either a change in leakage, or possibly resistance to moving.

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert!

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[PNachtwey]

I am trying to understand why there are no commercial hydraulic cylinders that can either measure the force at the rod end or the internal pressure in the cylinder.

They are easy to install but they need to be installed at the right place. It is best if the pressure sensors are truly monitoring the pressure in the cylinder. Too many people put the pressure sensors in a block between the valve and the cylinder where the oil is moving quickly so there is turbulence and "noise"

I have machine the becomes unaligned every now and then and crashes out.

This isn't very descriptive. Do you mean a multiple cylinder machine where the cylinders become misaligned so the machine binds?

Knowing either of the two values would let me send a signal to my PLC and stop the cylinder from damaging itself or the machine when it is in that unaligned state.

maybe. It depends on the speed of the PLC, the PLC speed of the PLC inputs, and your programming ability.

I feel like I am missing something because it seems like this should be fairly straightforward to implement.

It the problem is what I think it is then it is easy to fix.
This is press control 101.

https://deltamotion.com/peter/Videos/SyncPosForce.mp4

Pressure sensors that we like and have been recommended by our customers.

https://forum.deltamotion.com/t/pressure-transducers/151

Peter Nachtwey
Delta Computer Systems

http://www.deltamotion.com

http://forum.deltamotion.com/