Causes and elimination of walking deviation of Komatsu PC200 excavator (two)

1, dirt block the end of the drive system of the balance valve small hole, resulting in parking brake force can not be lifted

The machine when walking, if the pressure oil does not pass through the hole on the balance valve to promote the balance valve spool movement, the pressure oil can not pass through the slot on the balance valve to release the parking brake force, causing the motor can not walk normal rotation, causing excavator deviation. The elimination method is: cleaning the balance valve; when disassembling, must avoid the dirt to enter.

2 、 walk motor safety valve oil leakage

If the safety valve leaks, the system will lead to pressure is too low, so that the motor speed is not enough, so that there is running deviation. The elimination method is: replace the damaged walking motor safety valve; when judging, you can change the left and right motor safety valve to see whether the deflection when walking backward.

3, the machine deflection side of the walking ratio, valve output pressure (pressure control) is too low

The proportional valve can output the corresponding control oil pressure according to the length of the control stroke of the operation handle, so that the main control valve has a corresponding amount of movement, so as to control the speed of the work device. If the filter fails to change the oil filter, can cause the clogging of the filter element, oil filter bypass valve to open, dirty hydraulic oil in the case of unfiltered directly into the loop proportional valve, causing the slide valve valve was stuck, unable to control the oil by the side of the rotary machine deflection proportional valve left to turn the main control valve, leading to walking deviation. When checking, check the pressure of the walking proportional valve (3.3MPa). The removal method is: cleaning the valve body and the relevant oil circuit, replacing the hydraulic oil, filter core.