Author Topic: Double spool valve help (Read 8098 times)

jbthecamel · « **on:** October 10, 2015, 10:28:13 pm »

Hello, as per my log splitter post, I'm looking at buying a log splitter running off my kubota tractor

The splitters need a double spool valve, I'm not sure if I have one or not.

I have one quick fit hydraulic point mounted on the back under the wheel arch, and another directly on top of the rear axle / transmission assembly which I think used to be the top up point for the HST oil

??

shep53 · « **Reply #1 on:** October 11, 2015, 12:52:01 pm »

According to the brochure specs only a single spool valve . we have a log splitter , 70hp zetor works it but slow even on high revs , 120hp JD no waiting on the return and very low revs

jbthecamel · « **Reply #2 on:** October 11, 2015, 02:19:58 pm »

Hi thanks for your reply. I am having a little trouble understanding what you've written.

Without looking at the specs of the machine how would I be able to tell ? Also if it is only a single spool valve what is the other quickconnect hydraulic connection for ?

stufe35 · « **Reply #3 on:** October 11, 2015, 05:12:06 pm »

Usually for a log splitter you need a flow line and a return line.

From what you describe it sounds like that's what you have. The one where you topped up the oil being the return.

You plug in the lhydraulic pipes , set the hydraulics on your tractor to constant pumping, then the control handle on the log splitter controls the log splitter.

Hope that makes sense.

Ps from your other post your kubota will easily run a log splitter.

Cheers. Stu

shep53 · « **Reply #4 on:** October 11, 2015, 06:42:17 pm »

Each spool valve has its own lever so our JD has 4 levers and 8 connectors . For your log splitter you are creating a circle one valve pumps oil out and the second lets it go back , so yes if you can return the oil straight into the hydraulic system it will work with one valve . My point with the two tractors is that the JD has a bigger pump and oil flow so works the log splitter quickly on the down and up stroke with no waiting time . Can you not get a demo of the machine on your tractor

stufe35 · « **Reply #5 on:** October 11, 2015, 07:01:32 pm »

Shep. You are confusing matters. Double acting is something completely different. A tipping trailer is normally single acting...ie you pump oil into it as you tip the trailer, the oil is discharged out of the ram as the trailer comes back down under gravity.

A double acting ram powers down under hydraulic pressure....so on a tipping ram for the bucket on a front loader it normally powers in and out....double acting.

A main lift on the front loader on a tractor will normally only power up, and come down under gravity...single acting. A jcb 3cx front loader however powers down too....it is double acting.

A log splitter is normally double acting, though some are single acting, returning via a spring.
You do not need a double acting spool on the tractor though...the double acting spool is on the log splitter....it just needs a flow and return from the tractor to operate it.

shep53 · « **Reply #6 on:** October 11, 2015, 07:19:13 pm »

Sorry you are correct that was a bad example

jbthecamel · « **Reply #7 on:** October 11, 2015, 10:57:14 pm »

Ok thanks for your help, i'm just about there now.

The lever which controls the valve on the tractor has three positions. UP, DOWN, NEUTRAL, and FLOAT. The book is not much help but i'm guessing UP an DOWN is shall we say blow and suck. NEUTRAL does nothing, I have no idea what FLOAT would do. I'm guessing that to run the log splitter is would be set either the UP or DOWN position ?

stufe35 · « **Reply #8 on:** October 12, 2015, 07:51:20 am »

Up - activates the hydraulic pump to send oil to lift the rear arms....if you have something connected to the external service pipe it will send oil there too.

Neutral - holds the arms at the position they are at. (wont let them go down any further)

Down - releases the oil to let the arms go down. (it does not apply downward pressure, the arms (and any attached implement) come down under gravity)

Float - Applies no restriction to the arms so they can 'float' up and down....you might put it in this position when dragging an implement behind you that you want to follow the contours of the ground...like a topper perhaps.

To supply oil to your external service to power a log splitter or tip trailer, hold in the up position.

jbthecamel · « **Reply #9 on:** October 12, 2015, 11:19:55 am »

Thanks

shep53 · « **Reply #10 on:** October 12, 2015, 07:42:45 pm »

When in the up position you probably need to hold it there , if you let go it normally springs back to neutral , I use a ring cut from an inner tube to tie back