Kobelco excavator hydraulic system inspection method
1, main control valve pilot control pressure check
Install a T-shaped joint between the pilot oil pipe and the control oil of the main control valve, install a 4900kPa pressure gauge on the T-shaped joint, and operate the corresponding hydraulic pilot control valve handle, then the pressure gauge can display the control oil port. The pilot pressure.
2, inspection of the leakage of the rotary motor housing (models with rotary latch)
Checking the leakage of the swing motor housing is to check the performance of the swing motor. Follow the steps below:
(1) Remove the drain pipe on the T-joint of the swing motor
(2) Install a screw plug (3/4”-16) at the open end of the drain pipe, and install a nut (3/4”-16) at the opening of the T-shaped joint
(3) Remove the drain pipe from the central rotary joint, and install a nut (3/4”-16).
(4) Put one end of the drain pipe into a suitable measuring container.
(5) Insert the rotary pin into the locked position, and operate the rotary control valve for 1 min. (6) Measure the leakage of the rotary motor housing. When the set pressure of the rotary safety valve is (24000±490) kPa, the maximum leakage of the rotary motor housing is :201/mi (new motor), 231./min (motor after overhaul).
3. Inspection of the leakage of the rotary motor casing (models without rotary barrel pins)
(1) Stop the engine and release the oil pressure in the hydraulic system
(2) Remove the oil drain pipe on the T-joint of the swing motor
(3) Use a screw (3/4"-16) to plug the open end of the drain pipe, and a butterfly female (3/4"-16) to plug the oil port of the T-joint
(4) Remove the drain pipe from the central rotary joint and install a nut (3/4”-16).
(5) Put one end of the drain pipe into a suitable measuring container.
(6) Remove the brake and release the pilot oil pipe, so that the rotary brake is in the braking position.
(7) Start the engine, the power mode selector switch is at position Ⅲ, and the engine throttle knob is at position 10. The engine runs at high speed without load, and the engine speed is (1860±50) r/min
(8) Let the hydraulic oil temperature reach (55±5)℃.
(9) Operate the rotary control valve for 1 min, and measure the leakage of the rotary shell
10) Stop the engine, release the oil in the hydraulic system, release the swing parking brake to restart the engine, and operate the swing control valve to turn the swing motor to the new position.
Repeat the above steps and measure 3 times''
When the setting pressure of the rotary safety valve is (24000±490)kPa, the maximum leakage of the rotary motor housing is (new motor), 23L/min (motor after overhaul).
1. Inspection of the leakage of the walking motor housing
(1) Remove the drain pipe of the walking Naida, and plug the-end of the drain pipe with a screw plug.
(2) Connect a plastic hose to the drain port, and put the other end of the plastic hose into a suitable measuring container
(3) Catch the crawler with a crawler pin to prevent the operation of the walking control valve from turning for 1 min
(4) Measure the leakage of the traveling motor housing.
(5) Remove the track latch, and turn on the excavator's walking motor to another position.
(6) Repeat the above steps.
When the travel safety valve set pressure is (34300±490)kPa, the maximum leakage of the travel motor housing is: 15Lmin (new motor), 18L/min (motor after overhaul).
2, main pump exhaust
When the excavator repairs the main pump or replaces the hydraulic oil, the air in the hydraulic system must be discharged. The exhaust steps are as follows:
(1) Turn off the engine, remove the bleed plug from the top of the main pump, wait a few minutes until the main pump is filled with hydraulic oil, and then install the bleed plug. Start the engine at low speed and raise the starting arm to maintain the raised position of the boom.
(2) Stop the engine, and slowly lower the boom until the bucket hits the ground. This will pressurize the hydraulic tank.
(3) Slowly loosen the bleed screw plug and discharge the air until the hydraulic oil flows out, which indicates that the air in the main pump has been discharged.
(4) Tighten the bleed plug.
3, the release of hydraulic system pressure
Before the hydraulic tubing or components are disconnected or disassembled, the pressure of the hydraulic system must be released. The release method is as follows:
(1) Retract all the piston rod of the stick cylinder.
(2) Adjust the position of the bucket so that the bucket is flat on the ground when the movers are lowered.
(3) Lower the boom until the bucket is flat on the ground
(4) Turn off the engine, operate the joystick of the hydraulic control valve back and forth to release the pressure in the pilot system.
(5) Slowly loosen the bleed plug on the hydraulic oil tank to release the pressure.
(6) Tighten the bleed butterfly plug on the hydraulic oil tank.
(7) After the pressure of the hydraulic system is released, the hydraulic tubing and components can be disassembled.
