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| Illustration 1 | g01388617 |
Hydraulic schematic for the swing system (felling head) (1) Pilot oil manifold (2) Solenoid valve (swing parking brake) (3) Pilot control valve (4) Swing parking brake (5) Swing motor (6) Anti-reaction valves (7) Line relief valves (8) Implement control valve (9) Proportional solenoid valves (swing) (10) Swing control valve (11) Signal limiter valves (12) Pilot oil pump (13) Implement pump (14) Ball resolver (15) Main pumps (16) Hydraulic tank | |
Note: Illustration 1 shows the implement control valve with only the swing hydraulic circuit.
The oil delivery for the swing hydraulic circuit is supplied by implement pump (13). When the left joystick control is moved from the NEUTRAL position, solenoid valve (2) is energized. Swing parking brake (4) is released. The motor rotary group starts to rotate. The swing motor is mounted on top of the swing drive. The swing drive is installed on the upper structure. The swing drive reduces the motor speed by two stages. The swing drive rotates the upper structure.
ReferenceFor more information concerning the operation of the swing motor, refer to Systems Operation/Testing and Adjusting, "Swing Motor".
ReferenceFor more information concerning the operation of the swing drive, refer to Systems Operation/Testing and Adjusting, "Swing Drive".
ReferenceFor more information concerning the operation of the swing control valve, refer to Systems Operation/Testing and Adjusting, "Main Control Valve".
The oil delivery from implement pump (13) flows through implement control valve (8) to swing control valve (10) .
The oil delivery from pilot oil pump (12) flows to pilot oil manifold (1). When the hydraulic lockout is in the UNLOCKED position, the oil delivery from pilot oil pump (12) flows to pilot control valve (3). The oil then travels to proportional solenoid valves (9) .
When the left joystick control is moved to the SWING RIGHT position, solenoid valve (2) is energized. Pilot oil flows from pilot oil manifold (1) through swing parking brake solenoid valve (2) in order to release swing parking brake (4).
The oil delivery from pilot oil pump (12) flows from pilot control valve (3) of pilot oil manifold (1) into implement control valve (8). The pilot oil flows to proportional solenoid valves (9) of swing control valve (10). The proportional solenoid valve for the SWING RIGHT shifts. Pilot oil flows to the spool of swing control valve (10). The spool shifts. The pilot oil on the other end of the spool in swing control valve (10) flows through the proportional solenoid valve to hydraulic tank (16) .
As swing control valve (10) shifts, the oil delivery from implement pump (13) flows to swing motor (5) and signal limiter valve (11). The signal limiter valve regulates the maximum pressure in the swing circuit.
The load sensing signal, which is equal to the pressure in the swing system, flows through ball resolver (14) to port (PL) on implement valve (8) .
The load sensing signal flows out of port (PL) to implement pump (13) in order to upstroke implement pump (13) .
The oil delivery from implement pump (13) propels swing motor (5) .
Return oil from the motor rotary group flows through swing control valve (10). The return oil flows through implement control valve (8) to the oil cooler then to hydraulic tank (16). The upper structure swings to the right (right direction).
When the left joystick control is released, the proportional solenoid valve is de-energized. The pilot oil stops flowing to swing control valve (10). The spring in the control valve shifts the spool to the NEUTRAL position. The load sensing signal decreases. Implement pump (13) destrokes.
The solenoid valve for the swing parking brake is de-energized. The pilot oil flow is stopped to swing parking brake (4). The force of the spring actuates swing parking brake (4) .
The swing left operation is similar to the swing right operation.
When the left joystick control is moved to the SWING LEFT position, pilot oil flows from the proportional solenoid valve to swing control valve (10). The spool in swing control valve (10) shifts downward. The oil delivery from implement pump (13) flows to swing motor (5). For a swing left operation, the supply ports and return ports are reverse of the swing right operation. This causes the upper structure to swing to the left (left direction).
When the left joystick control is returned to the NEUTRAL position, proportional solenoid valve (9) is de-energized. The springs on each end of swing control valve (10) shifts the spool in swing control valve (10) to the NEUTRAL position. The oil flow to swing motor (5) is blocked by swing control valve (10) .
The solenoid valve for the swing parking brake is de-energized. The pilot oil flow is stopped to swing parking brake (4). The force of the spring actuates swing parking brake (4).