Causes and repair methods of sudden failure of hydraulic control valve of hydraulic press

1. The hydraulic control valve core and valve body of the hydraulic press continue to wear during use, causing changes in the size, shape and surface quality of the parts.
2. The balance spring, valve core and valve seat in the hydraulic control valve operate under long-term variable loads, causing fatigue and cracks, causing the spring to break or the valve seat sealing surface to fall off and be damaged.
3. The residual stress remaining during the processing of the hydraulic control valve parts of the hydraulic press and the external load stress during use exceed the yield strength of the part material, and the parts will deform.
4. There is too much water or acidic substances mixed in the hydraulic oil. After being used for a long time, the parts in the hydraulic control valve will be corroded, causing it to lose its due accuracy.
5. The radial force of the fluid between the hydraulic machine valve core and the valve sleeve is unbalanced, which eventually causes the valve core to press against the inner wall of the valve sleeve, causing a clamping phenomenon.
6. When manufacturing or repairing the hydraulic control valve, the specified technical requirements are not met; or the parts are not properly maintained, rusted, or mixed with dirt, etc.
If the above situation occurs, the performance of the hydraulic control valve of the hydraulic press can be restored with only certain maintenance.
Generally speaking, the maintenance process is not complicated and only requires some simple processing techniques, such as grinding, polishing, and plating. For some obsolete equipment, other parts can still be used normally, but the hydraulic control valve fails. There may not be a suitable hydraulic control valve on the market, and repair measures must be taken.
The main contents of hydraulic press repair: the valve core of the slide valve component and the hole in the valve body. When the two fitting clearances increase by about 20%-25% compared to the assembly clearance value specified in the product drawing, the valve core must be repaired and developed by increasing the size; the valve core and valve of poppet valve components, When the conical valve seat seal is poorly connected, the cone valve can automatically fill the gap under the action of the spring. Therefore, it only needs grinding and repair; repair of valve components such as stuck, hair-biting, grooves, etc.; pressure regulating spring Inspection and replacement; replacement of seals, etc.