The key hints: the common faults and elimination measures of the excavator with the broken hammer: the hydraulic system working principle of the 1. excavator with the broken hammer is configured by the hydraulic hammer excavator. No matter whether the broken hammer works or not, the other working devices of the excavator can still work normally.
1. working principle of hydraulic system for excavator equipped with broken hammer
The excavator with hydraulic breaking hammer can work normally regardless of whether the hammer is working or not.
The main reversing valve of the system generally adopts the reserve valve reserved in the main working valve group of the excavator. The pressure oil used for the crushing hammer is provided by a main pump of the excavator, and the working pressure of the broken hammer is adjusted by adding the overflow valve; the high pressure cut-off valve must be added to the inlet and outlet of the broken hammer so as to facilitate the adjustment of the parameters of the working system and the adjustment of the working system. Maintenance.
2. common faults
Failure of operation, nitrogen leakage of broken hammer, improper maintenance and so on, can cause the wear of the working valve of the broken hammer, the burst of the pipeline, the partial overheating of the hydraulic oil and so on. The reason is that the technology allocation is unreasonable, and the two is improper site management.
The working pressure of the broken hammer is generally 20MPa, the flow rate is about 170L/min, and the system pressure of the excavator is generally 30MPa and the flow of the single main pump is 250L/min, so the overflow valve needs to undertake the heavy shunting and unloading work. Once the overflow valve is damaged and not easily detected, the broken hammer works under the ultra high pressure, first is the pipe burst, the hydraulic oil is partly overheated, then the main reversing valve is seriously worn, the other valve core of the main working valve group of the excavator (the next valve core pointing at the main oil road in the middle) is polluted; The return oil of the broken hammer does not pass the cooler directly through the oil filter, which may cause the oil temperature of the working oil road to be high or even too high, which seriously affects the life of the hydraulic components (especially the seals).
3. barrier measures
The most effective way to prevent these faults is to improve the hydraulic circuit. First, add the overload valve at the main reversing valve (with the same type of overload valve used with the movable arm or the bucket work valve), its adjustment pressure should be larger than the overflow valve 2~3MPa, which can effectively reduce the impact of the system and ensure that the pressure of the overflow valve is not too high when the overflow valve is damaged; two Before the device, to ensure that the work is cooled and cooled in time; three when the flow of the main pump exceeds the maximum flow of the hammer 2 times, a diversion valve is installed in front of the main reversing valve to reduce the load of the overflow valve and prevent the overheating caused by a large amount of oil supply through the overflow valve.
Practice has proved that the improved EX300 excavator (old machine) and KRB140 hydraulic hammer have achieved good results.
