In the troubleshooting, we follow the "first easy" principle to do the following checks: First, check the hydraulic system outside the fault, including the engine power is sufficient, the speed is enough; manual control mechanism is loose, stuck or travel Not in place; voltage, current is normal. Second, check the hydraulic fuel tank, oil, oil filter is dirty and so on. Exclude the above factors, and then according to different failures to diagnose.
1. Diagnosis of the failure of walking
(1) Check the engine and hydraulic pump, hydraulic motor and drive wheel connection parts are mechanical failure; check installed in the front drive motor bypass valve is in the state, if the high and low pressure oil chamber will be connected.
(2) Check the braking system. If the engine is working properly, if the brake is energized, if the brake can be disengaged, if it can not be disengaged, check whether there is a mechanical failure. If it is not, you can use the drag method to release the brake (turn the manual pump handle counterclockwise ), Do the following check.
(3) Check the high pressure and charge pressure of the main circuit of the walking hydraulic system. In the two high-pressure pressure junctions then take 60MPa of the oil pressure gauge, the pressure in the pressure gauge port 4MPa hydraulic table and test machine. At normal temperature (30 ~ 60 ℃), the charge pressure is about 2 ~ 6MPa, the machine is not less than 2 ~ 4MPa when walking; when walking resistance, the maximum pressure of the main circuit can reach 38MPa, normal walking is not less than 20MPa. If both are normal, the fault is mechanical.
If the charge pressure is lower than the specified value, the running joystick will be placed in the middle of the adjustment charge pump relief valve (Note: adjust the oil pressure gauge, the adjustment can not be too large, and remember the original position), if the pressure Can not reach the normal value or no change in the pressure gauge readings, can determine the relief valve or charge pump is faulty; if the machine does not walk when the charge pressure is normal, so when the running pressure to pay a lot of pressure drop, you should test the motor on the return pipe Of the back pressure, the pressure should be not less than 2MPa, if the pressure is low that the motor spindle valve and low pressure relief valve is faulty; when the charge pressure is higher than the specified value, adjustable relief valve pressure, if not , The relief valve is faulty.
If the high pressure is low, the fault may be caused by hydraulic pump, hydraulic motor, multi-function valve block (including high pressure relief valve). Can remove the pump two executives, with a plug plug the pump outlet, the engine idling, slowly forward, after a small angle to promote the walking bar, if the pressure is not normal should check the multi-functional valve block, if the multi-function valve Normal, compared to the hydraulic pump due to leakage; such as high pressure normal, the motor is faulty. How to determine which motor is faulty or both motors are faulty? Can be removed before and after the motor into and out of the tubing, blocked with the plug after the test machine, the pressure is still not normal motor that is faulty motor can also be measured by measuring the amount of oil to judge, is to open the motor drain and Then the volume of the cylinder, under normal pressure oil leakage 3 ~ 4L / min is normal, otherwise the motor is faulty.
2 Vibration system fault diagnosis
(1) After removing the electrical fault, check the condition of the elastic coupling of the vibration motor and the vibration shaft and the lubricating oil inside the vibration shaft. Excessive lubricating oil will make the vibration frequency does not go, usually due to damage to the motor shaft seal caused by oil leakage. If the vibration shaft spline sleeve wear serious, can also lead to vibration failure, this time should pay pressure, the system pressure to detect, so as to make a diagnosis.
(2) Since the front and rear vibration systems of the machine are both independent and interrelated (shared fuel pump), the "element replacement method" can be used for diagnosis. For example, there is a round of low frequency, the front and rear motor can be interchangeable, if the fault has been transferred, then the fault is on the pump, otherwise the motor is faulty. Similarly, the same "interchange method" can be used for the displacement control valve for frequency conversion operation.