Komatsu 220-6 working device, rotation, detection of running circuit oil pressure

1. Detection of unloading oil pressure: The engine idling at high speed, measuring the oil pressure of all the joysticks in the neutral position.

2. Install the oil pressure test table

(1) Remove the pressure measuring screw plug (diameter lOmm, P=1.25ram) from the circuit under test, and install the oil pressure test table.

(58. 8MPa).

(2) Put the work device safely on the ground, then turn off the engine, loosen the filler cap, and release the hydraulic tank.

The pressure then places the safety lock lever in the locked position.

3. Main pump overflow pressure detection

(1) Low-pressure setting (when the oil pressure is 31. 9MPa): The engine is idling at high speed, except for the traveling device, each working device

When overflowing, measure the oil pressure. However, the set pressure of the swing motor and the boom top safety valve is lower than the set main overflow.

Flow pressure, so the measured value is the relief valve relief pressure.

To measure the swing relief pressure when the swing lock switch is turned ON.

(2) High pressure setting (when the oil pressure is 34.8 MPa (355 kg/cm2)): When running, the engine idling at high speed, and the oil pressure is measured when each side travels and overflows. Test conditions are: placing a spacer under the track teeth or placing a spacer between the drive wheel and the track frame to lock the track and allow the travel loop to overflow.

4. Detection of PC valve output pressure (servo piston input pressure)

 2. Detecting oil pressure

The engine idling at high speed and measuring the oil pressure when the stick (retracts) overflows. Check that the servo piston input pressure is approximately 1/2 of the main pump output pressure. If an abnormal condition occurs in the LS valve or servo piston, the servo piston input pressure will be the same as or zero to the main pump output pressure.

(4) LS valve output pressure (servo piston input pressure) and LS valve pressure difference detection

1. Installation hydraulic test chart

Remove the pressure tap and install the oil pressure gauge. 8MPa. On the servo valve side of the pressure gauge of 39. 2MPa, installed on the main pump output port side of the 58. 8MPa pressure gauge.

2. LS valve output pressure (servo piston input pressure) detection

(1) Remove the pressure tap plug and install the oil pressure gauge. Install a 39. 2MPa pressure gauge on the servo valve side, and output the oil in the main pump.

A pressure gauge of 58. 8 MPa was installed on the mouth side.

(2) The oil pressure when the single-side travel motor is idling. Use the working device to support the track assembly on one side. The engine is idling at high speed. Measure the main pump output pressure and servo piston input pressure according to Table 3-10. Measure the oil pressure of the pump before measuring the oil pressure of the pump.

2. LS valve pressure difference detection

(1) Detection with a differential pressure gauge:

1 Remove the pressure tap plug and install connector C3 on the hose.

2 Install the differential pressure gauge C4 in the front pump circuit

Table 3 - 10 LS valve output pressure detection