Snow plow angle valve

[jthaxter]

Sorry, I know this has been discussed LOTS, but - I have an old Fisher plow blade with two SA cylinders. I have it mounted up front on my Kubota 2350DT and I would like to tie into the hydraulics, adding another valve to control the plow angle. The hydraulic circuit on the tractor goes through the power steering to power-beyond the FEL. I am thinking I can add another valve after the FEL to control the plow angle.

I have a few questions.
1) Can I even install a valve after the FEL to control the plow angle? That is, does the two spool FEL control valve have to have power beyond to do this?
2) Assuming I can install a valve after the FEL, what kind of valve? I think I need a single spool valve, but then things get murky. Closed center? Open center? Relief valve? Crossover? I can't figure out what applies and what doesn't.
3) Does the new valve need power beyond, or is there nothing "beyond" the new valve that needs power, since it just returns to the tank?

I need to be sure I'm doing the right thing, since the valve and hoses will cost more than the plow did. This needs to be as low-budget as possible. It's so low, for the last two winters I have angled the plow manually, but that is getting old. Or, maybe it's just me that's getting old.

Thanks

 

[Rustyiron]

I'm making a few assumptitons here but If your mounting the blade to the loader and you don't use your bucket for a mount for the blade, you could buy a couple (pairs) of quick connect hyd. fittings to put on the lines that operate the dump function of the bucket and use that for angling the blade pretty cheaply.:thumbsup:

 

[zzvyb6]

I run my plow off the loader valve, angle and up down. Use car brake lines to reduce the flow. Works just peachy. The 2 single acting cylinders are mechanically linked and thus work like one double acting cylinder. Connectors from TSC. Even though the cylinders are probably rated at only 1000 psi, I push my 2000 psi thru them gently and never had a problem in 10 years.

 

[jthaxter]

Thanks much, I like the sound of this. In my cheapo mode, I simply have the plow slung under the bucket with a chain to a hook on the back side of the bucket for the lift. I have the bucket curled way in when plowing. I welded up a crude adapter on the frame of the tractor, and that pushes the plow. I wasn't sure about switching the dump spool over for the plow angle, but that sounds like an option. I saw discussions on "regen" and I thought I should stay away from the loader valves for that reason. The bucket would have to stay in position while plowing (I guess it would - the plow weight would tip back on the bucket even if it tended to droop). The loader dump valve has a "dump" detent for quick dump - does that matter? (I could just avoid it manually)

 

[Mike_VT]

I just did adapted a plow and ran lines from the rear remotes to the front. Also put in a crossover relief valve. No issues works great.

Mike

 

[jfay]

Mike
Can you tell me what you used for the crossover and how you plumbed it ? I am thinking about doing the same thing.
Jamie

 

[J_J]

Here is the drawing for a double cross over valve.

Surplus Center - 1/2 NPT 30 GPM 1500-3000 PSI HYD CUSHION VALVE

http://www.surpluscenter.com/Drawing/DR9-4019-50-H.pdf

 

[jthaxter]

Just to finish up this thread. I obtained a couple of Snap-Tite connectors (from snap-tite.com) and 1/4" hose and then plugged into the FEL curl lines on the loader valve. Lo and behold, I now have hydraulic angling of the plow! Had I known it was this easy I would have done it right from the start. I've spent less than $300 for the entire plow rig, and it all works just fine.

 

[Gizmo2]

Just to finish up this thread. I obtained a couple of Snap-Tite connectors (from snap-tite.com) and 1/4" hose and then plugged into the FEL curl lines on the loader valve. Lo and behold, I now have hydraulic angling of the plow! Had I known it was this easy I would have done it right from the start. I've spent less than $300 for the entire plow rig, and it all works just fine.

Not so fast! Did I miss the pictures?

 

[LD1]

. The 2 single acting cylinders are mechanically linked and thus work like one double acting cylinder.

Not quite. TWO SA cylinders of the same size have the SAME volume.

Of you substitute that with ONE DA cylinder, The two functions are going to require different volumes of fluid. That means one was is going to be faster with less power, and the other slower with more power.

But that isnt the real issue. A standard crossover valve like used in a smowplow wont work with a DA cylinder. It appears that the one JJ listed MAY work with a DA cylinder?? I am not sure. But it would have to do more than just dump to the other side of the cylinder. It would also need to relief back to the tank.

Just to finish up this thread. I obtained a couple of Snap-Tite connectors (from snap-tite.com) and 1/4" hose and then plugged into the FEL curl lines on the loader valve. Lo and behold, I now have hydraulic angling of the plow! Had I known it was this easy I would have done it right from the start. I've spent less than $300 for the entire plow rig, and it all works just fine.

What did you do for the crossover valve??? I assure you, at some point in time, you are going to need or wished you had one.

Not sure the exact geometry of your plow or size?, but most use a 1-1/2" hydraulic cylinder mounted so that the blade has a ~4x's mechanical advantage on the cylinder.

What all of that means is that if your tractor is capable of pushing with 1500 lbs of force on the edge of the blade (which is should be more than capable of), you would be pressurizing the hyd. lines and cylinder with ~3500psi right there.

What if your tractor can push more? What about shock loads? Catching a curb?

A crossover valve is highly reccomended:thumbsup:

 

[jthaxter]

Man, this setup is so hokey I'm embarrassed to show it. But anyway, here it is. The plow frame had been modified by some previous owner, so I just extended it to the tractor and used a couple of pins for attachment and lift swivel. I had to make the setup the day before a big storm, so there wasn't a lot of engineering put into it. I figured I'd change it later - but it's still working, so I've never bothered.

 

[J_J]

On the cross over valve statement, there is no relief to tank. It is there to take the shock pressure, and dump to the other side, as long as the relief pressure is exceeded.

The cyl limits are dictated by the amount of fluid in the rod end. If you dump the rod end fluid to the base end, the cyl rod will not be extended to max. So therefore, I believe the cyl max angles will not be equal. Not a big deal though.

 

[J_J]

The crossover valve does not have a tank port. It just transfers to the other side of the cyl.

The max angle will be dictated by the amount of fluid in the rod end, therefore stroke extension. The angles will not be equal because of the amount of fluid in the rod end will not fully extend the base end cyl stroke.

Also, max angle will be limited to where the cyl is mounted relative to the baseline of the blade. If the cyl is close in to the pivot point, you will have more angle and faster operation.

 

[Leejohn]

Did you use the plow when the storm came in?

 

[LD1]

On the cross over valve statement, there is no relief to tank. It is there to take the shock pressure, and dump to the other side, as long as the relief pressure is exceeded.

The cyl limits are dictated by the amount of fluid in the rod end. If you dump the rod end fluid to the base end, the cyl rod will not be extended to max. So therefore, I believe the cyl max angles will not be equal. Not a big deal though.

If the rod is extended, there is more volume in the base of the cylinder. And since there is already fluid in the rod side, if you force the cylinder to collapse, and the base end fluid tries to enter the rod side, there is no room for it:confused2:

I guess I am a little confused as to how it is supposed to operate then. I can see it absorbing some shock, but as a crossover????

 

[jthaxter]

Been using the plow for two years now. I figured "this thing isn't going to last", but it has. That very first storm was a foot of wet, heavy snow, and the rig handled it just fine. I'm more surprised than most. It's also nice that the plow can be raised quite high to push the tops of snowbanks back.

 

[J_J]

If the force on the plow pushes on the cyl with enough force, the mechanical action will force the rod to either extend or collapse, forcing fluid from one side of the cyl to the other side, through the relief valve .

If the cyl is half way out, there is some fluid in the base end, and there is less fluid in the rod end.

 

[LD1]

If the force on the plow pushes on the cyl with enough force, the mechanical action will force the rod to either extend or collapse, forcing fluid from one side of the cyl to the other side, through the relief valve .

If the cyl is half way out, there is some fluid in the base end, and there is less fluid in the rod end.

If the cylinder is half way out (or any distance out for that matter)....

And the plow catches something that will force the rod to collapse......

There is a greater volume of fluid being displaced on the base end than there is room for on the rod end.

Quick example:

Cylinder has to collapse 2" due to object being struck.

That will displace say 20 ounces of fluid on the base side, but that 2" it collapsed only made room for 15 ounces of fluid. So where does the rest go?

IF you had a hydraulic cylinder and took OUT the piston seals, and filled EVERYTHING with fluid so there was NO air in the system.....

And had the cylinder FULLY extended and the ports blocked (or even connected to each other for that matter), the cylinder will NOT collapse. Because the rod occupies area INSIDE the cylinder when it collapses. THAT fluid that it displaces has to go SOMEWHERE other than remain inside the cylinder curcuit.

That is why I was wondering if that cushion valve you linked had a return back to tank.