Mechanically Operated Hydraulic Shut-Off Valve

[markborges]

I have a hydraulic/valve question--I hope this is the right forum. I need some sort of plunger operated hydraulic shut off valve.

We are developing a rotary mower that attaches to a skid steer loader. Hydraulicly powered, the mower must shut down when it is raised/lowered +/-20 degrees with respect to the tractor. Without electrical power, some sort of push/pull plunger to release the hydraulic pressure must be used. AT least, I can not think of anything else.

My question is such a valve available and by whom? I am also skeptical about how responsive this setup would be; ie start to shut off at 15 deg and then be completely off at 25 degrees. It would be desireable to be on at 19 degrees and off at 21 degrees--in other words, once it trips it would trip fast and then reset itself.

A few details about the system.....
1000 rpm
32 gpm
2000 psi useable pressure
I realize that there is probably more to shutting down the system then what I have described; however, I would like to hear what others think before I go any further.

Any ideas?

Thanks

Mark

 

[MintJulep]

Any hydraulic valve manufacturer should be able to provide a variety of mechanically actuated valves that could be operated by a cam or linkage.

A two-degree dead band might be hard to achieve

 

[MadMango]

Search for Parker, HydraForce, Deltrol... you should be able to find what you are looking for.

Ray Reynolds
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[Iskit4iam]

Why can't you use the 12V system to power a valve?

 

[ccw]

Hi markborges,

I am thinking a mobile hydraulics, two position, 4 way cam operated, spring return, spool valve should work. The "operated" position should shunt the P-T (supply to tank return) lines and block the A-B lines between the valve and the hydraulic motor. The normal or quiescent position (spring held) has P to A, T to B or vice-versa. The 15-25 degree to 19-21 degree function can be accomplished with some simple mechanical linkage. Since this is probably safety related, the linkage, fittings, mounts, and valve should be robust and protected from damage or tampering in the field.

 

[EdDanzer]

We us a HydraForce MP10-20 for this type of application, and have also used a diverter valve.

 

[markborges]

Thank you for all the replies.

Right now I am using a walvoil sd14 with a roller mounted on the plunger single acting on B to tank with A pluged. I am not sure if the tractors pump has a variable displacement or not. I would use the MP10-20 but It does not have the GPMs.

I counted out electronics because of the power source problem; but there is some definite advantages; ie., mercury level swithc etc.

Thanks
Mark

 

[NGiLuzzu]

Mark,
have you already tried to drop down your question in the "Valve Engineering" Forum too?
Go to Forum408 within this site...
Bye, 'NGL

 

[jefftn]

for your hydraulic valve try

http://www.transnordic.uk.com

good luck