Cub Cadet U-Channel Beam Style - Manual (Page 18)

2010 Log Splitters
14
The open-center control valve does four things: See Figure 3.6.
1. Regulate:
It regulates fluid pressure.
• If the pressure exceeds a pre-set limit, the relief valve opens, returning fluid directly to the tank.
• In any no-load condition, pressure should not exceed 300 PSI (20 BAR).
2. Forward:
It drives the ram toward the base plate.
• In the forward position, the control valve directs pressurized fluid through the hose to the port at the rear of
the cylinder.
• This drives the piston up the bore, displacing fluid from the shaft side of the cylinder.
• The control valve allows displaced fluid to leave the shaft end of the cylinder through the trunnion, return-
ing to the control valve.
• The control valve dumps displaced fluid back into the tank through the low pressure hose.
3. Retract:
It draws the ram away from the base plate.
• In the retract position, the control valve sends fluid through the trunnion it is mounted to, to the shaft side
of the cylinder.
• This drives the piston down the bore, displacing fluid from the base side of the cylinder.
• The control valve allows displaced fluid to leave the base end of the cylinder through the high pressure
hose, returning to the control valve.
• The control valve dumps displaced fluid back into the tank through the low pressure hose.
• The control lever is held in the retract position by a detent. When the piston bottoms-out, the build-up of
pressure of between 500 and 2,000 PSI forces the valve out of detent, returning it to neutral.
4. Neutral:
In the neutral position, fluid from the pump is dumped directly back into the tank through the low pressure hose.
Relief Valve Settings
Valve part
number
Tonnage
Relief valve
setting
+ 100
718-04706 27 and 33 3400 PSI
(234 bar)
718-04739 21 2700 PSI
(186 bar)
718-04740 25 3200 PSI
(221 bar)
Figure 3.6
Control valve