The pilot relief valve of the Kato excavator is installed in the pilot gear, and the pilot gear pump is connected in series with the two main pumps. The hydraulic system continuously generates pressure to supply different equipment
(1) Hydraulic pressure is supplied to the left and right pilot control valves and travel pilot valves.
(2) The hydraulic pressure supply solenoid valve controls the rotary parking brake, high power function and walking speed.
(3) The hydraulic pressure provides a signal for pressure increase in straight forward travel.
(4) Hydraulic pressure is supplied to the contact signal of the forearm balance valve
(5) The hydraulic pressure is supplied to the upper turntable and the walking pressure switch.
(6) APC proportional pressure reducing control valve.
Therefore, if the circuit pressure is too low or too high, it will cause a series of failures in the pressure measurement method
1. Pressure measurement method
(1) Stop the engine and press the air vent rubber plug on the fuel tank to reduce the air pressure in the fuel tank.
(2) Install the pressure gauge 0~98MPa to the sensor connector at the inlet of the pilot filter
(3) Turn on the start switch and start the engine
(4) Check whether there is oil leakage at the connection of the pressure gauge.
(5) Turn on the working mode to "Heavy duty", the APC mode to "H", and the automatic deceleration mode to "OFF" and the economy mode to "OFF".
(6) Let the engine run and heat until the oil temperature reaches (50±5)℃
(7) Fully rotate the accelerator knob to the low idle and high idle stop positions, and read the pressure gauge readings at each position.
[note]
① The pilot relief valve pressure at low idle speed is 314~343MPa.
②The pilot relief valve pressure at high idle speed is 343~422MPa 2. The pressure adjustment method uses the relief valve installed in the pilot gear pump to adjust the pressure, loosen the lock nut and turn the adjustment screw to adjust the pressure, and then lock it. Nut.
note
①When the tightening torque reaches 294N·m, the pressure of the regulating relief valve will reach (300kgf/m2).
②Adjust the screw to the left and rotate it one turn to increase the pressure by about 1.7MPa, and rotate the screw to the right to reduce the pressure by about 1.7MPa.
