Rapid diagnosis and elimination of typical faults of pilot overflow valve Author: daijinshan liuxiaobin, engineering corps training brigade of Shenyang Military Region, sanlibao Town, Jinzhou District, Dalian City, Liaoning Province. In practice, in order to maximize its efficiency and protect the control system, it is a key step to accurately and timely diagnose and eliminate the failure of the pilot relief valve
1. If the control fails, the main engine will not move.
the pilot relief valve fails, which will cause the main engine to fail to act. According to the phenomenon, the causes are analyzed as follows: the spring of the pilot valve spool is broken; The anion hole is blocked; Poor sealing of pilot valve port; The main valve element is stuck. The corresponding elimination measures are: replace or add a flat pad at the broken part for emergency use; Cleaning and dredging; Grind or break the oil circuit for emergency use; Grinding and cleaning. Imported metering pump
2. Unstable pressure limit
the pilot type overflow valve has unstable pressure limit, which is manifested by low or high hydraulic system pressure, weak action of hydraulic actuator or burst of oil pipe, pump body and valve body
the causes of this fault are: improper pressure adjustment; Pilot valve cartridge domestic lithium battery material enterprises will participate in global competition in the future, and the spring will be bent or softened; Dirty oil or poor oil flow. The corresponding elimination measures are: readjustment; Correction, padding or replacement; Replace and clean
the unstable pressure limit of the pilot relief valve is a gradual fault, which usually occurs on the construction machinery with a large number of hours of reserved motorcycles; The failure of the pilot type overflow valve is a sudden failure, which usually occurs on construction machinery with less reserve motorcycle hours. After troubleshooting, readjust the pressure controlled by the pilot relief valve according to the pressure limited by the system of the machine
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