When my favorite machine can't perform normal construction work, do I feel depressed in my heart. As a novice excavator driver who has just entered the industry, he has no idea about the failure of the excavator. Take a recent case of excavator failure, Kobelco SK350LC-10 cylinder can't move. I don't know what went wrong.
Let's follow the excavator maintenance master to troubleshoot the fault. If the corresponding pilot handle is operated and the cylinder cannot be operated, the inspection, analysis and troubleshooting can be carried out in the following order. If both rotation and walking can move normally, the inspection should be continued according to the following methods:
(1) Check whether the pilot control oil pressure of the corresponding working oil cylinder is normal. If the pilot oil pressure is very low or there is no pilot oil pressure, the corresponding multi-way reversing valve stem cannot be flexibly switched, the oil flow to the oil cylinder is blocked, and the oil cylinder will not move. No pilot oil pressure or low pilot oil pressure may be caused by the following reasons:
① The corresponding pilot spool has been bonded or jammed by foreign matter, so that the pilot spool cannot be reversed. The foreign matter should be removed or matched and polished.
②The corresponding pilot valve spring is broken, so that the small pilot spool cannot be flexibly switched, the pilot oil circuit is in a semi-closed state, and the pilot oil pressure is low or there is no pilot oil pressure. Therefore, the spring should be replaced.
③The oil passage of the pilot oil inlet or outlet is blocked by foreign matter, and there is no pilot oil output. The foreign matter should be removed to make the oil passage unblocked.
④ If the piston is stuck in the sliding sleeve, the small pilot valve core cannot be reversed. The piston should be able to move freely in the sliding sleeve.
(2) Check whether the overflow pressure of the secondary overflow valve is normal. If the valve stem of the multi-way valve can be flexibly switched, a pressure gauge can be installed at the oil cylinder oil inlet port to measure the oil cylinder oil inlet pressure. If the pressure is very low or no pressure at this time, you can adjust the secondary relief valve and observe whether there is any change in the display value of the pressure gauge. If the relief pressure can be adjusted higher, then adjust to the rated pressure value; if the relief pressure value is not high , It means that the secondary overflow is faulty. The secondary relief valve failures generally include:
① The pressure regulating spring is broken and should be replaced.
②The clearance between the valve core and the valve sleeve is too large, the sealing performance is poor, the overflow pressure cannot be established, and the valve core should be replaced. When oil red
When the displayed value of the port pressure gauge reaches the rated relief pressure, if the cylinder still cannot move or the movement is stuck, it means that the fault is inside the cylinder.
(3) The failure of the oil cylinder generally has the following situations:
① The piston of the oil cylinder is damaged, the piston should be replaced.
②There is a foreign body stuck in the cylinder, which prevents the piston from moving, and the foreign body in the cylinder should be removed.
③ The piston rod is severely bent and should be repaired by calibrating the piston rod.
