In the process of using the excavator, many excavators master reflects the "slow and slow movement of the excavator boom".
The excavation of the excavator's big arm is slow
The reason: compensation solenoid valve problems lead to the slow opening of the excavator's middle arm, the LS loop throttle block of the bucket valve core (if the pressure is low, check whether the regenerated one-way valve is stuck or throttle the foreign body, the pressure is normally checked by the pressure compensating valve), which causes the excavator's arm to slow down and the global excavator maintenance factory shares the excavation. The middle arm of the machine opens the cause of the slow failure.
Trouble solving method: the cover of the hydraulic pump of the excavator is worn, needs to be repaired, the bucket rod retaining valve is broken down, the middle arm of the excavator opens slowly, the bucket rod oil cylinder has trouble causing the slow opening of the excavator's middle arm and the loosening of the cylinder piston of the excavator, the need for tightening or reinstalling, the piston pulling of the excavator, the need for maintenance or replacement, the malfunction of the overflow valve of the middle arm. It is necessary to check for the slow opening of the arm in the excavator, the cartridge valve in the rod retaining valve and whether the two position two way valve is blocked or the spring is broken.
Slow down movement of the excavator's big arm
1. Check or replace the down arm pressure sensor to check whether the spool of the pilot control valve is worn or not, and whether the spring is broken.
2, confirm the pilot pressure is above 3.0MPa when the whole arm is lowered and the throttle is high.
3, check P1 unload proportional valve and P1 pump proportional valve in the large arm drop full stroke and action of the current value is normal, if abnormal, the need to check or replace the proportional valve / solenoid valve or controller.
4. Measure the P1 unloading ratio valve of the A7 port of the solenoid valve group at two times 0.8-1.2MPa.
5. Test whether the two pressure of P1 pump proportional valve in the whole arm and the high throttle is at 2.0-2.5Mpa. If not, the proportional valve should be replaced.
6. Test whether the current value of the walking diameter proportional valve is normal when walking around the whole travel and the empty turn, such as abnormal, need to replace the walking pressure sensor, the proportional valve and the controller.
7. When neutral or high throttle is used, measure whether the two times pressure of the walking diameter proportional valve is at 0.8MPa, if not, replace the proportional valve.
8, the lower arm speed is slow. It is necessary to check whether there is abnormal wear or poor opening and closing of the retaining valve, the big arm spool and the locking valve tappet.
9, when the body is unable to lift, it is necessary to check whether the spring of the boom spool and regenerative valve is damaged or not. In addition, the port overflow valve needs to be checked for impurities.
10. When the main boom is slow and the overflow pressure is low, check the main relief valve, for example, the pressure is abnormal, so it needs to be reset.
Excavators in daily work, every time to lift and drop the arm and so on must be smooth operation, so when the excavator has the above failure phenomenon, it is necessary to stop the inspection, the so-called magic road is not mistaken for firewood workers, only the machine runs well, your efficiency is high.
