Removal of the inability to work in a excavator

3 years after a Komatsu production company PC - 2006 type excavator in driving, failure, inability to work driving difficult, specific performance: after the start, if traveling to encounter greater resistance or swerve in engineering, the engine is easy to flameout; when the bucket cylinder contraction to the limit position or the bucket rod and a movable arm up to the limit position, the engine is easy to flameout; when the working speed of the machine is too fast, too easy to turn off the engine.

In order to eliminate this fault, first look at the driving room oil pressure, water temperature, alarm and other instrument instructions, are no exception. As the engine has just completed the repair, and no-load, the engine is running normally, the no-load increase of the throttle, the engine speed is no abnormal response. After further judgment, it is assumed that the hydraulic system of the machine is faulty. The hydraulic system is driven by a dual variable pump driven by the engine, the hydraulic cylinder and rotary motor work, through the main pump regulator to adjust the flow and pressure of the pump. According to the pressure and the working machine system in action the slower were normal, only in the sudden load increases when the abnormal situation, the judge may be due to output of the main pump is not normal, the engine load changes more than the self adjustment ability caused extinction phenomenon.

After checking, the main variable pump is adjusted by the pump regulator through the PC-EPC electromagnetic valve to regulate the flow and pressure of the pump. When the external load exceeds the output torque of the engine, the engine speed is reduced, and the speed signal is transmitted to the pump regulator. When the engine speed is reduced to the minimum speed when the pump regulator is a current signal control action of PC-EPC solenoid valve, so that the pump output flow is reduced, thereby reducing the engine load, the engine speed recovery without the occurrence of sudden stalling phenomenon.

Taking into account the main pump regulator and PC-EPC solenoid valve are located outside the engine, it is prone to failure. Therefore, check the main pump adjuster first. After examination, the output voltage of each foot is no exception, and the adjustment of the indicator is no exception, the regulator in good condition; and then check the PC-EPC solenoid valve, solenoid valve when the disconnect switch CN-C13, found it full of mud and sand, has a semi contact state. When the engine is reloaded and the engine is started again, the working state of the machine is restored to normal.