The lead circuit includes an oil absorbing circuit, oil supply circuit and an oil return circuit.
The pilot pump is equipped with a relief valve, and the oil of the hydraulic tank is received by the oil absorbing filter.
The oil volume discharged from the pilot pump flows through the pipeline filter into the remote control valve, EPPR valve (electromagnetic proportional pressure regulator), solenoid valve assembly, rotary stop brake, main control valve, and safety locking solenoid valve.
1. Hyundai excavator oil absorbing circuit, oil supply loop and return loop
The pumping pump receives the oil of the hydraulic tank, then pilot the oil to discharge the oil through the pipe filter to the safety solenoid valve, and the oil is filtered through the pipe filter. The pilot pump is equipped with a first-leading overflow valve to limit the leading circuit pressure.
Oil through the pipeline filter flows to the remote control valve by the safety solenoid valve.
Back oil flow to the hydraulic tank.
2, safety valve (safe joystick)
When the joystick of the safety solenoid valve moves downward, the oil flows into the remote control valve through the solenoid valve and the pipe filter. When the operating lever of the safety solenoid valve moves upward, the oil does not flow into the remote control valve because the oil passage is blocked.
3, big arm priority system
When the composite operation of the swivel and the large arm or the arm, the actuation speed of the large arm or the arm is below the normal speed. In order to increase productivity, use a rotary reduction system. When using the heavy load mode, the lead oil of the pilot pump flows into the PNS oil port of the main control valve in the electromagnetic valve. The PNS hydraulic pressure pushes the rotary displacement valve core to a lower position, and the oil flow to the rotary motor is reduced. Then, the large arm or the arm speed increase. This process is the big arm priority system
4, walking speed control system
When the walking speed switch is pressed, the walking speed solenoid valve is activated, and the oil flow of the oil flow in the pilot pump is flowed into the pilot Valve PK oil port in the motor. As a result, the control plunger is pushed by the main oil flow, and the emissions reach the minimum pressing speed switch, the travel speed solenoid valve is returned to the initial position, and the hydraulic oil of the PK oil is returned to the hydraulic tank. As a result, the control plunger is pushed back by the main oil, and the emissions reach the maximum.
5, main overflow pressure improvement system
When the power lifting switch of the left joystick is pressed to ON, the power lifting solenoid valve is activated, the drain of the pilot pump flows into the main control valve of the main spill valve PZ oil port; then the main force of the pressure valve set The excavation force will be increased from 330kgfm2 to 360kgcm2. If you continue to press the power lifting switch, the 8S post will be released.
6, maximum flow cutting system
When the brake mode is selected, the maximum flow cutting the solenoid valve is automatically activated. Therefore, the pilot pressure (transported to the regulator, the pump emissions will be reduced)
7, rotary parking brake release
When the rotary manipulation is operated, the first oil flows into the SH oil port of the shuttle valve, the pressure moving the spool, the oil exit of the pilot valve, flows into the PG port.
The pressure is applied to the rotary motor, so the brake is released. When the rotary joystick is set in the intermediate position, the oil in the rotary motor cylinder is discharged, so the brake is used.
