The main reason why the engine of the excavator is blocked is that the power of the engine and the hydraulic pump is not matched, and the reasons for this are 1) lack of engine power and 2) excessive power of the hydraulic pump
The reasons for the lack of engine power include: the water temperature is too high, the air intake is insufficient, the fuel (there is air, the filter element is blocked, the diesel pump is worn, and the injection timing is incorrect), the oil viscosity, the engine body is worn or the air leaks
It was difficult to start the cold engine before the pump calibration of PC60. After the pump calibration, the diesel oil flowed into the engine oil due to the poor sealing in the pump, and then the oil level appeared to rise. After the pump was installed from the top, the white smoke of the cold engine was very thick. After the inspection, it was found that the timing gear was one tooth late.
The boom piston rod and the boom piston rod appear blue, which may be caused by the high oil temperature caused by the poor selection valve. (some oil temperature is high) the machine suddenly fails to operate. Check the safety determination lever switch and whether the voltage to the safety determination solenoid valve is 24V, and whether the solenoid valve coil is disconnected. During the normal operation of the pilot pump, if the oil outlet pipe is loosened, the hydraulic oil will gradually flow out and there is no pressure, Because the pump displacement is very small.
There is a lag in the recovery of the small arm of the Kobelco-5 machine. During the operation and rotation, if the operation of the big arm or the action of the small arm will produce the phenomenon of rotation block, it is judged that it is caused by the clogging of the filter element at the oil inlet of the pilot valve in the side playground. The analysis causes are as follows: the pilot valve is short of oil due to the clogging of the filter element, and the pilot pressure is slow during the operation, so it is delayed. When operating other actions, the pilot oil is diverted to other actions, The common rotary valve is even less, and the rotary valve core returns to the middle position, so the rotation is blocked\
Kobelco-5, the mechanical operation lasted about 40 minutes, and the temperature was around 30 degrees and it was cloudy. If the cover of the development machine was turned over, the water temperature was around 9 grids. The user reflected that the water temperature of the machine was normal. Because he felt that the action was weak, other repair personnel took the valve core of the multi-way valve for electroplating, and the water temperature increased. However, the cover of the development machine was turned over and the machine could operate normally. After that, there was oil discharged from the exhaust pipe of the machine, Therefore, the engine was overhauled. After the engine was overhauled, the machinery presented the above appearance. After arriving at the site, the water tank of the machine was checked to be free of bubbles, the start was normal, the smoke color was normal, the water pump was normal from the water tank, the air volume of the electric fan standing beside the engine was normal, the engine was basically cleaned, the temperature was measured, the water temperature was 95 degrees, the upper part of the hydraulic oil radiator was 70 degrees, and the front part was 60 degrees, However, when the surface temperature of the hydraulic pump is measured, it is found that the surface temperature is around 80 degrees. If the flow of the hydraulic pump is reduced at this moment, if the water temperature is decreased, it can be judged as a hydraulic fault. After replacing the pump bladder, plunger and oil distribution cover, the mechanical operation is normal. Under the condition of 30 degrees, the temperature of the operating water with large throttle is stable at around 80 degrees.
