Symptom:
During the construction of a Kato hd1023 hydraulic excavator on the construction site, the straight line of the excavator deviates to the left, and the left line is weak. However, it is difficult for the excavator to turn to the right on soft soil, and when the engine is at low speed, the right side can walk, but the left side can't. I don't know what's the matter?
Causes and inspection methods for failure of Kato hd1023 hydraulic excavator with weak left travel:
1 in addition to checking that the excavator hydraulic pump supplies high-pressure oil to the travel motor, it also supplies oil to the jib hydraulic cylinder and the boom hydraulic cylinder. Check that the large and small boom hydraulic cylinders work normally, and confirm that the excavator hydraulic pump has no problem
The main control valve of 2 excavator is controlled by the pilot oil circuit. If the pressure of the pilot oil circuit is low, the pilot oil cannot push the travel valve stem, or the travel of the travel valve stem is small, it will lead to the failure of left travel. The pressure of the pilot oil entering the main control valves of the left and right travel motors is tested with a pressure gauge, and the pressure of the left and right pilot oil is 4MPa, so it is determined that the pilot control system of the excavator is normal
3. The main faults of the control valve are as follows:
The pressure of the main relief valve is adjusted too low,
The pressure of oil port overflow valve is adjusted too low,
The wear of valve stem and valve hole increases the fit clearance
All of the above faults can lead to weak left walking.
4 since the boom hydraulic cylinder and the jib hydraulic cylinder can work normally, the pressure of the main safety valve should be normal
5. After the pressure of the oil port relief valve is increased, the test is carried out, and the fault is still the same, so it should not be the fault of the oil port relief valve
6 check whether the fit clearance between the valve rod and the valve hole is increased. Exchange the left and right walking oil pipes. It is found that the left walking is weak, but now the right walking is weak. This proves that the fit clearance between the valve rod and the valve hole is increased, resulting in leakage and left walking is weak.
