Common faults of excavator equipped with crushing hammer
for excavators equipped with hydraulic crushing hammer, whether the crushing hammer works or not, other working devices of the excavator can still work normally. The main reversing valve of the system generally adopts the standby valve reserved on the main working valve group of the excavator. The pressure oil for the crushing hammer is provided by a main pump of the excavator, and the working pressure of the crushing hammer is adjusted by adding an overflow valve; The high-pressure stop valve must be installed at the inlet and outlet of the crushing hammer. The pressure testing machine of Jinan testing machine factory for excavator maintenance is specially tested to facilitate the adjustment and maintenance of working system parameters by domestic manufacturers and wholesalers specializing in the production of testing machines
1. Common faults
misoperation, nitrogen leakage of the crushing hammer, improper maintenance and other phenomena will cause the wear of the working valve of the crushing hammer, pipeline burst, local overheating of hydraulic oil and other faults. The reasons are unreasonable technical configuration and improper on-site management. The light-weight solution of modern removal tools
the working pressure of the crushing hammer is generally 20MPa and the flow is about 170l/min, while the system pressure of the excavator is generally 30MPa and the flow of a single main pump is 250L/min. therefore, the overflow valve needs to undertake heavy shunt unloading work. Once the overflow valve is damaged but not easy to be detected, the breaking hammer will work under ultra-high pressure. First, the pipeline bursts and the hydraulic oil is partially overheated. Then, the main reversing valve is seriously worn and the hydraulic circuit controlled by other valve cores of the excavator's main working valve group (the next valve core pointed by the main oil circuit at the middle position) is polluted; Because the return oil of the crushing hammer generally returns to the oil tank through the oil filter without going through the cooler, Sumitomo excavator maintenance such a circulating oil circuit may cause the oil temperature of the working oil circuit to be too high or even too high, seriously affecting the service life of hydraulic components (especially seals)
2. Troubleshooting measures
the most effective way to prevent the above failures is to improve the hydraulic circuit. One is to add an overload valve at the main reversing valve (an overload valve of the same model as the boom or bucket working valve can be selected), and its set pressure should be 2~3mpa greater than the overflow valve, which can effectively reduce the impact of the system and ensure that the system pressure will not be too high when the overflow valve is damaged; Second, connect the oil return pipeline of the working oil circuit to the cooler to ensure that the working oil return is cooled in time; Third, when the flow of the main pump exceeds twice the maximum flow of the crushing hammer, Sumitomo excavator maintenance and repair will install a diverter valve in front of the main reversing valve to reduce the load of the overflow valve and prevent overheating caused by a large amount of oil supply passing through the overflow valve with the economic development
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