Key hint: the repair method of the bucket cylinder of Daewoo DH320 excavator: a DH320 excavator produced by Daewoo produced a sudden noise in the construction of a sudden bucket cylinder. At the beginning, it was considered that the sound was a piston breaking or the seal ring on the piston, the piston was driven by hydraulic oil, or the sound of the inner wall of the piston cylinder.
In the construction of a Daewoo production DH320 excavator, the abrupt bucket cylinder gave out a different noise. At the beginning, it was considered that the sound was the sound of the piston broken or the seal ring damaged, the piston was driven by hydraulic oil, or the sound of the inner wall of the piston cylinder. As a result, it was preliminarily determined that the hydraulic cylinder had basically been unused, but the latest purchase of a bucket cylinder was 15 days fast, and it would also affect 3-4 T815 dump trucks, disassemble the cylinder head and pull out the piston rod in the case of last resort: the piston was not broken, the oil seal on the piston was not damaged, and the piston was locked tightly. The mother has been damaged and stuck at the bottom of the cylinder; the locking ring of the lock nut is cut off on the piston rod with the ring connected to the piston rod; the effective part of the free cylinder is not found to have a scratched part. So the crane was lifted with a crane, trying to shake the damaged nut, but the nut was too tight to work. Other ways to avoid injury and cylinder cylinder and end cover should be retained between the location, so decided to turn off the welding part, the end cover and cylinder body separately. After measuring the length of the cylinder body and the position of the oil hole, the welding part of the car is successfully separated from the cylinder body.
After removing the waste nut, use oil to remove its mark (although the mark can not be fully worn, but the piston can not reach the position, does not affect the normal use), then the end cover and cylinder body are found in the original position and welded well. After the heat insulation and inspection are qualified, the machine can be installed.
Meanwhile, in order to avoid the recurrence of the same accident, the locking device of the nut is replaced by the M10 bolt with the diameter of 5mm. The locking nut of the pressure cylinder piston of the original fluid is a circular nut, and the lock nut is a through hole, and the piston rod is a blind hole, and the locking clamping ring blocks the nut to prevent it from withdrawing. When repairing, the newly processed lock nut is six angle nut, and the nut is tightened after the screw is tightened on the piston rod with the lock nut to drill a hole with a diameter of 10.5mm. The bolt fastener is applied to the nut of the position bolt to prevent its withdrawal. The position bolt of the locking nut on the piston rod (originally used as the ring) mainly bears the shear force of the locking nut. The original lock ring is cut off mainly because of the small shear strength, and the shear strength of the 8.8 grade M10 bolt is 2 times that of the original lock ring, and the bolt can be effectively prevented from being cut after using the bolt. The main force part in the hydraulic cylinder is the piston. The piston passes the force to the piston rod by connecting the thread (or the shaft shoulder). The hole of the new drill on the piston rod is not connected with the force part of the thread. It will not affect the strength and stiffness of the piston rod, so it does not affect its use.
This method only used 16H to repair hydraulic cylinders, but up to now, it has been used for more than six months.
