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Analysis of the reasons why the cylinder does not move in the normal operation of a 200-ton four-column hydraulic press

Posted by: Oil Punch 2021-10-11 Comments Off on Analysis of the reasons why the cylinder does not move in the normal operation of a 200-ton four-column hydraulic press

The oil cylinder is a very important part of the operation of a four-column Hydraulic Press. The editor has also introduced a lot of questions about the oil cylinder before, but today we are going to talk about the reasons why the oil cylinder does not move under normal operation? How to solve it?

1. The resistance of the moving parts is too large.

Removal method: Eliminate the jamming, wedging and other problems existing in the actuator of the 200-ton four-column hydraulic press; improve the guide and lubrication state of the moving parts.

2. The oil pressure at the inlet of the 200-ton four-column hydraulic machine is too low to reach the specified value.

Troubleshooting method: check the leakage of the relevant oil system and eliminate the leakage; check whether the sealing ring at the piston and piston rod is damaged, aging, loose, etc.; check whether the hydraulic pump and pressure valve are faulty.

3. The oil does not enter the hydraulic cylinder.

Remedy: Check whether the oil pipes, oil circuits, especially hose joints are blocked, check the relevant oil circuits from the cylinder to the pump and remove the blockage; check whether the sealing between the poppet valve of the overflow valve and the valve seat is good; Check whether the solenoid valve spring is damaged or the solenoid coil is burned out; whether the oil circuit is not sensitive to switching.

4. The fitting of the sliding parts of the hydraulic cylinder itself is too tight, and the sealing friction is too large.

Removal method: H8/f8 fit should be used between the piston rod and the guide sleeve; check whether the size of the sealing ring is strictly processed according to the standard; if the V-shaped sealing ring is used, the sealing friction should be adjusted to a moderate degree.

5. Due to improper design and manufacture of the 200-ton four-column hydraulic press, when the piston returns to the end point, the effective working area of ​​the pressure oil acting on the piston is too small.

Removal method: improve the design and re-manufacture.

6. ​​The lateral load on the piston rod is too large, especially if it is too strong or pulls the cylinder or seizes.

Remedy: When installing the hydraulic cylinder, ensure that the axis position of the cylinder is consistent with the direction of movement; make the load borne by the hydraulic cylinder pass through the cylinder axis as much as possible to avoid eccentricity; when the long hydraulic cylinder rotates horizontally, the piston rod will deflect due to its own weight. The guide sleeves and pistons generate eccentric load, which leads to damage to the seal of the cylinder head, oil leakage, and piston sleep syndrome. The following measures can be taken for this: Increase the piston plan, adjust the outer circle of the piston and process it into a convex shape, so that the piston can self-position , To improve the stress condition to reduce and avoid cylinder pulling; the connection between the piston and the piston rod adopts a spherical joint.

7. The back pressure of the hydraulic cylinder is too large.

Exclusion method: reduce back pressure. The important reason for the failure of the hydraulic cylinder is that the oil pressure at the oil inlet is too low, that is, the working pressure is insufficient. The main reasons for the insufficient working pressure of the hydraulic system are the failure of the hydraulic pump, drive motor and pressure regulating valve. Other reasons include: oil filter blockage, oil passage diameter is too small, oil viscosity is too high or too low; Excessive air in the liquid; serious pollution; wrong connection of the pipeline; damage to the pressure gauge, etc.