Hello!I'm building a device that is supposed to measure the (pulling) force from a hydraulic cylinder. It is partially working but it have some problems that I would appriciate som input on...

 

What is the problem in particular? You should be able to measure the pressure, and calculate the Force, if the axial area of the piston has been determined.

 

" Pulling " ?, maybe a force from plunger end, in which case subtract plunger aria from cylinder aria.

 

Hello!I'm building a device that is supposed to measure the (pulling) force from a hydraulic cylinder. It is partially working but it have some problems that I would appriciate som input on...

Some input on what? What is the problem you are having? We are not mind readers.

 

What is the problem in particular? You should be able to measure the pressure, and calculate the Force, if the axial area of the piston has been determined.

Only while it's static and, even then, if it's a typical industrial cylinder there can be a significant amount of friction that is taking up some of the load.

It would be helpful to have some idea of the scale of the force being measured and what level of accuracy/precision is needed.

 

Hello!I'm building a device that is supposed to measure the (pulling) force from a hydraulic cylinder. It is partially working but it have some problems that I would appriciate som input on...

use a strain gauge in/at the cylinder construction.
Picbuster

 

I used to have a copy of this very useful book which you may find very helpful. Have a look on Amazon for a second hand copy.
Hydraulics and Pneumatics: A Technician's and Engineer's Guide
Book by E. A. Parr

 

The calculated pulling force, retracting the piston rod, is pressure times the active piston area, which is the area of the cylinder diameter minus the area of the rod diameter.and then the effective pulling force is that calculated force minus the friction force. So you can use a load cell that you calibrate by applying a tension load. Of course, with a load cell and a display you also need an instrument amplifier and a stable regulated power supply for the load cell. And probably you should also have a pressure transducer to monitor the pressure, because cylinder force without pressure is only half of the information.

 

You got that part backwards. That part right there. No, there. There! No, look where I'm pointing. Right THERE! GEEZ! How can I help you if you don't pay attention.

 

You got that part backwards. That part right there. No, there. There! No, look where I'm pointing. Right THERE! GEEZ! How can I help you if you don't pay attention.

Are you saying that my explanation is confusing? My explanations are NEVER confusing. Or are you implying something else???

 

Are you saying that my explanation is confusing? My explanations are NEVER confusing. Or are you implying something else???

I'm trying to point the guy in the right direction. Unfortunately none of us know where he is, which way he's facing or where he wants to go. Until then, he's not listening to us.

 

I'm trying to point the guy in the right direction. Unfortunately none of us know where he is, which way he's facing or where he wants to go. Until then, he's not listening to us.

T.R. yes, I can see that a good bit more information is indeed needed so that any answers can relate accurately to the need. That is very typical of what happens here. Really, measuring the retraction force of a cylinder is not that complex if one has an accurate pressure gage and an adequate pressure source. The procedure provides a plot of force per pressure allowing any level to be determined.

As "the engineer" I have done quite a few pneumatic designs and several hydraulic ones and so I do have a few clues about the way some of it works. There are still those areas that are clearly magic, but that is in the much more complex realm. I wonder if this is a school work problem, or similar. There do exist disaster projects that do not have a happy solution, I once inherited a project of a "ball-screw efficiency tester" from the designer who left the company after his project shipped. Unfortunately the users were officers in the air force of a small country in a hostile part of the world, and had no clues as to how it should work. Fortunately for me, when the war started the device was destroyed and so the issue ended.

 

Fortunately for me, when the war started the device was destroyed and so the issue ended.

Darn wars! They ruin everything!

The extent of my hydraulic experience is with a 72 Chevy Nova that kept blowing high pressure hoses due to the proximity of hot header exhaust tubes. Literally once every two years. Could have been worse. Could have been a war and my high pressure hose could have been destroyed.