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| Illustration 1 | g01430988 |
Schematic for the hydraulic system (1) Auxiliary control valve (2) Line relief valve for rod end of auxiliary cylinder (3) Line relief valve for head end of auxiliary cylinder (4) Auxiliary cylinder (5) Line relief valve for rod end of tilt cylinder (6) Line relief valve for head end of tilt cylinder (7) Pressure tap for rod end of tilt cylinder (8) Pressure tap for head end of tilt cylinder (9) Tilt cylinder (10) Ride control accumulator (11) Ride control solenoid valve (12) Lift cylinders (13) Makeup valve (14) Main control valve (15) Lift circuit relief valve (16) Pilot control valve (17) Main relief valve (18) Pilot diverter solenoid valve (19) Pilot diverter solenoid valve (20) Lift arm positioner valve (21) Float sequence valve (22) Ride control solenoid valve (23) Check valve (24) Line for steering and bucket control valve - remote control (25) Implement and steering solenoid valve (26) Selector and pressure control valve (27) Line to steering control valve (28) Pressure tap for the parking brake system (29) Check valve (30) Pressure tap for the main hydraulic system (31) Check valve (32) Parking brake oil pressure switch (33) Breaker relief valve (34) Portable hydraulic pump quick connect coupler (35) Pilot oil pressure reducing valve (36) Return line from the brake accumulator charging valve (37) Automatic lubrication system connection port (38) Line to brake release sequence valve (39) Pilot and braking pump (40) Steering pump (41) Implement pump (42) Automatic lubrication system connection port (43) Hydraulic oil filters (44) Hydraulic tank (45) Portable hydraulic pump quick connect coupler (46) Line for the brake accumulator charging valve (47) Parking brake control valve (48) Pressure tap for the pilot circuit (49) Line for parking brake | |
The ride control system provides a means for dampening the bucket forces which produce a pitching motion as the machine travels over rough terrain.
The main components of the ride control system are ride control accumulator (10), ride control solenoid valve (11), lift cylinders (12) and ride control solenoid valve (22).
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| Illustration 2 | g01249424 |
(11) Ride control solenoid valve | |
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| Illustration 3 | g01249422 |
(10) Ride control accumulator (22) Ride control solenoid valve | |
Ride control accumulator (10), ride control solenoid valve (11) and ride control solenoid valve (22) are located on the front frame of the machine, forward of the articulation point.
Ride control solenoid valve (11) is mounted under the front cover on the front frame.
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| Illustration 4 | g01249426 |
(50) Ride control switch (51) Ride control indicator | |
Ride control switch (50) is mounted in the switch panel in the operator station. Ride control indicator (51) is located on the indicator panel in the operator station.
When the ride control system is activated, the head end oil in lift cylinders (12) is connected to ride control accumulator (10). Ride control accumulator (10) provides a cushioning effect to the lift cylinder head end oil, allowing the lift cylinders to extend and retract slightly. The bucket can move as a balance weight against the movement of the machine.
Ride control switch (50) has three positions, the OFF position, the AUTO position and the SERVICE position.
OFF Position
Ride control solenoid valve (11) and ride control solenoid valve (22) are normally closed valves. When the lift spool in main control valve (14) is in the HOLD position and ride control switch (50) is in the OFF position, the coils in ride control solenoid valve (11) and ride control solenoid valve (22) are not energized. A spring in the ride control solenoid valves hold the solenoid valve spools in the closed position. With the solenoid valve spools in the closed position, the ride control system will not operate.
When the ride control system is in the OFF position, the orifice between lift cylinders (12) and ride control accumulator (10) allows a continual sensing of the lift cylinder pressure. When a load is in the bucket, pressure increases in the head end of the lift cylinders. This pressure passes through the orifice into ride control accumulator (10) to compress the nitrogen charge. This prevents the bucket from moving when the ride control system is activated.
AUTO Position
When ride control switch (50) is moved to the AUTO position, the ride control system will automatically activate when the machine ground speed exceeds 5 km/h (3 mph). Ride control indicator (51) will illuminate when the ride control system is activated.
When the lift spool is in the HOLD position and ride control switch (50) is moved to the AUTO position and ground speed of the machine exceeds 5 km/h (3 mph), the coils in ride control solenoid valve (11) and ride control solenoid valve (22) are energized. When the solenoid valve coils are energized it causes the solenoid valve spools to move against the spring force to the OPEN position.
When ride control solenoid valve (11) is in the OPEN position, lift cylinder head end oil is open to ride control accumulator (10). When ride control solenoid valve (22) is in the OPEN position, lift cylinder rod end oil is open to hydraulic tank (44) .
As the machine moves across rough terrain with a loaded bucket, the forces of the load act against the lift cylinders and the oil in the head end of the lift cylinders. The oil in the head end of the lift cylinders is felt at ride control accumulator (10) .
Ride control accumulator (10) has a nitrogen pre-charge that resists the head end oil pressure and acts as a shock absorber.
SERVICE Position
The SERVICE position is used for testing and troubleshooting the ride control system.
When ride control switch (50) is moved to the SERVICE position, the ride control system will be activated. Ride control switch (50) will return to the OFF position when released. Ride control indicator (51) will illuminate when the ride control system is activated.
When ride control switch (50) is moved to the SERVICE position, the ride control system operates the same as "AUTO Position" except that the system is activated regardless of ground speed.