For additional information on the hydraulic system, refer to Hydraulic Schematic, KENR6525.
HOLD Position
Note: Detailed oil flow is not shown for the HOLD position. Refer to Illustration 1 for references to components.
When the engine is running, the charge pump (not shown) sends pilot oil to pressure accumulator (19) through line (20). Pilot oil is available to the electrohydraulic pilot solenoids.
The valve spools in the HOLD position block the passages to the rod end and to the head end of the hydraulic cylinders. The oil is trapped and the implements do not move. In the HOLD position, the spring centers the valve spool.
Raise Operation
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| Illustration 1 | g01930534 |
Raise operation (1) Dead electronic lower valve (Ripper circuit) (11) Anti-drift valve (16) Ripper cylinder (17) Relief valve (multipurpose bucket and ripper) (19) Accumulator (20) Flow from the charge circuit of the right drive pump (22) Margin relief valve (23) Ripper control valve (24) Pilot control solenoid (26) Implement pump (27) Hydraulic oil tank | |
When the ripper control lever is moved to the RAISE position, the solenoids allow pilot oil to flow to the right end of ripper valve spool (23). This causes the valve spool to move to the left.
The movement of ripper valve spool (23) causes the load signal pressure to increase. The pressure at implement pump (26) increases. The oil from implement pump (26) now flows through the ripper valve spool to the rod ends of ripper cylinders (16). This causes the cylinder pistons and rods to retract. The movement of the cylinder pistons and rods pushes oil out of the head ends of the ripper cylinders.
The oil from the rod end flows into the valve bank. Then, the oil travels back to hydraulic tank (27) .
There are no detents on the ripper control. When the ripper control lever is released, the lever moves to the HOLD position. The spring moves ripper valve spool (23) back to the HOLD position. The oil in the ripper cylinders is blocked by the ripper valve spool. Therefore, movement of the cylinders is stopped until the ripper control lever is moved again.
Lower Operation
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| Illustration 2 | g01930535 |
Lower operation (1) Dead electronic lower valve (Ripper circuit) (11) Anti-drift valve (16) Ripper cylinder (17) Relief valve (multipurpose bucket and ripper) (19) Accumulator (20) Flow from the charge circuit of the right drive pump (22) Margin relief valve (23) Ripper control valve (24) Pilot control solenoid (26) Implement pump (27) Hydraulic oil tank | |
When the ripper control lever is moved to the LOWER position, the solenoids allow pilot oil flow to the left end of ripper valve spool (23). This causes the valve spool to move to the right.
The movement of ripper valve spool (23) causes the load signal pressure to increase. The pressure at implement pump (26) increases. The oil from implement pump (26) now flows to the head ends of ripper cylinders (16). This causes the cylinder pistons and rods to extend. The movement of the cylinder pistons and rods pushes oil out of the rod ends of the ripper cylinders.
The oil from the rod end flows into the valve bank. Then, the oil travels back to hydraulic tank (27) .
When the ripper control lever is released, the lever moves to the HOLD position. The spring moves ripper valve spool (23) back to the HOLD position. The oil in the ripper cylinders is blocked by ripper valve spool (23). Therefore, movement of the cylinders is stopped until the ripper control lever is moved again.
Dead Engine Lower
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| Illustration 3 | g01930536 |
Dead engine lower (1) Dead electronic lower valve (Ripper circuit) (11) Anti-drift valve (16) Ripper cylinder (17) Relief valve (multipurpose bucket and ripper) (19) Accumulator (20) Flow from the charge circuit of the right drive pump (22) Margin relief valve (23) Ripper control valve (24) Pilot control solenoid (26) Implement pump (27) Hydraulic oil tank | |
The implement circuit may still be operated when the engine is dead. Accumulator (19) stores potential energy while the engine is running by accumulating a quantity of pressurized hydraulic oil. When the engine is dead, the accumulator supplies this oil to the pilot valve.
When the operator moves the ripper control lever, oil flows from accumulator (19) to the LOWER end of ripper valve spool (23). The spool is shifted and the oil that was trapped in the ripper cylinders flows back to the hydraulic tank as gravity lowers the attachment to the ground.
When the back of the machine is off of the ground, there is pressure on the rod end of ripper cylinders (16). Oil from the accumulator can now be used as pilot oil in order to shift ripper valve spool (23) to the RAISE position. The oil that was trapped in the rod end of the ripper cylinders flows back to the hydraulic tank as the machine lowers.
Dead Electronic Lower
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| Illustration 4 | g01930538 |
Dead electronic lower (1) Dead electronic lower valve (Ripper circuit) (11) Anti-drift valve (16) Ripper cylinder (17) Relief valve (multipurpose bucket and ripper) (19) Accumulator (20) Flow from the charge circuit of the right drive pump (22) Margin relief valve (23) Ripper control valve (24) Pilot control solenoid (26) Implement pump (27) Hydraulic oil tank | |
If the engine is dead and the electronics are dead then the oil pressure that is stored in the accumulator is not usable for lowering ripper cylinders (16). If this is the case then dead electronic lower valve (1) needs to be turned on and the oil from ripper cylinders (16) flows back to the tank as gravity lowers the attachment.
Note: Dead electronic lower valve (1) is located under the floorplate of the cab on the right front side of the frame.
Dead Accumulator and Dead Engine Lower
If the accumulator has no charge then use the process that is located in "Dead Electronic Lower" in order to lower the attachment.
Note: Dead electronic lower valve (1) is located under the floorplate of the cab on the right front side of the frame.