Analyze the common faults in the use of long arm excavator

With the development of construction projects, excavator lengthening is used more and more, especially for municipal construction, subway traffic, sewage reconstruction and other projects, because it can better help excavator control to realize the construction of the foundation river, deep ditch and other earth excavation operations, and the performance is self-evident, but after the use of the lengthening arm, there are often some problems. What are the differences? The following Shandong Tianuo construction machinery to give you a good introduction.

Excavator walking and bucket no action, boom and bucket rod action is slow.

Many people reflect that this failure occurs after replacing the seal of the control valve assembly. After testing, the pressure when the pump receives the bucket is 1.5Mpa, which is far less than the normal value of 28.5Mpa. A plug is found on the faulty side, but a plug is installed on the original plug. The machine works properly after switching the correct position. After replacing the seal of the control valve assembly, the original maintenance personnel installed the reverse position of the valve and plug of the valve group.

After converting into an excavator and lengthening the arm, the whole car is slow and weak

The response received by the extended arm manufacturer said that the pilot pump oil seal had just been replaced, but it had been working normally for more than ten minutes after replacement, and then suddenly it was not working. According to this situation, it is suspected that the pilot music is insufficient. After measuring the pilot pressure of the lengthened arm is very low, it is decided to decompose the pilot pump.

It is found that the skeleton oil seal of the input shaft of the pilot pump has been extruded. There are two reasons for this. One is the installation problem, the other is the high pressure. Further decomposition found that the oil seal direction of the pilot pump is reversed. This is the cause of the failure. When the skeleton oil seal is not completely damaged at the beginning of work, it can still work normally. Because the skeleton oil seal can only withstand low pressure, the oil seal is damaged quickly, resulting in the pilot pressure oil leaking from the damaged place

The piston rod of the bucket rod cylinder retracts automatically after the engine starts

After inspection, one other action is normal: two after lifting the boom bucket rod sinking faster. The fault is still the same after the pilot pipe exchange bucket rod, indicating that the oil disorder in the control valve or bucket rod is in line with the principle of easy first and difficult later. Disassemble and check the control valve stem and find that the valve stem is stuck in the piston rod retractable position. Remove the valve stem after moving with a rubber head and a copper rod. There is shining iron and contact the bucket rod sinking faster. It is judged that the root cause is the lengthening of the control excavator and the pull of the bucket rod cylinder, which is confirmed after disassembling and checking the bucket rod cylinder.