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| Illustration 1 | g00834679 |
Attachment coupler tilt system (5) Bank valve (17) Joystick (23) Solenoid valve (24) Solenoid valve (25) Solenoid valve (26) Solenoid valve (30) Hydraulic tank (31) Piston pump (36) Compensating cylinders (40) Implement section of bank valve (coupler tilt) (47) Control valve (Compensating cylinders) (50) Load control valve (coupler tilt) (51) Tilt cylinder (coupler tilt) (CP1) Pressure for coupler tilt (LS) Load sense oil (P) Pilot oil (PP) Pump pressure (R) Return oil (S) Suction oil | |
Tilt control valve (40) of bank valve (5) is operated by pilot oil pressure from joystick control (17). Refer to the Systems Operation/Testing and Adjusting, "Joystick Control" for additional information on joystick control of the tilt system.
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| Illustration 2 | g00685887 |
Location of push button (1) for tilt function for the quick coupler on early type of joystick | |
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| Illustration 3 | g00685898 |
Location of push button (1) for tilt function for the quick coupler on later type of joystick (1) | |
In order to tilt the quick coupler in a backward direction, press push button (1) and hold the push button (1) . Then push joystick (17) to the left. In order to tilt the quick coupler forward, press the push button (1) and hold the push button. Then push joystick (17) to the right. Push button (1) energizes solenoid valves (23), (24), and (25) .
When the tilt back is selected, pilot pressure is transmitted from the joystick through solenoid valve (25) to tilt control valve (40) of the bank valve.
Pump oil flows from the tilt control valve through compensating valve (47) and load control valve (50) to the head end of the tilt cylinder (51). As the cylinder extends the quick coupler is tilted back and oil from the rod end flows through compensating valve (47) through the bank valve to the tank.
Load pressure for the tilt system is transmitted through the load sensing resolver network of the bank valve. If the pressure is higher than the load pressure in any other circuit that is in operation at the same time, the pressure is transmitted to the pump compensator. The pump compensator adjusts the output of the pump.
When the joystick is moved to the HOLD position, the load control valve for the tilt cylinder is closed by spring force. The load control valve blocks oil in the head end of the tilt cylinder. This holds the quick coupler at the selected angle. The check valves in the compensating valve will close. This will trap oil in compensating cylinders (36) and in the lines between the compensating cylinders (36) and the tilt cylinder (51) .
When the tilt forward for the quick coupler is selected, pump oil flows to the rod end of the tilt cylinder (51). The load control valve (50) is opened by oil that flows to the rod end. Oil flows from the head end through the load control valve (50), the compensating valve (47) and the bank valve (5) to the tank (30) .
The load control valve meters oil from the head end in proportion to the pressure in the rod end. This ensures that the quick coupler maintains the selected speed. This also ensures that the quick coupler does not tilt forward suddenly. Whenever the flow stops, the load control valve blocks oil in the head end of the cylinder and this prevents further movement.