1. Internal leakage of oil cylinder; 2. Internal leakage at control valve hole and valve rod; 3. Overload overflow valve is poor; 4. The valve rod is not in the middle position; 5. PPC valve is not in the middle position. Hydraulic cylinder maintenance process: 1. Whether the hydraulic lock becomes normal when it is in the determined position, if so, check the PPC valve first; 2. Conduct oil cylinder plugging oil port test, Shanghai Hydraulic station Check whether the oil cylinder is defective, and repair the oil cylinder if it is; 3. Replace the overload overflow valve and check whether it is the fault of the overload overflow valve; 4. Whether the valve rod is jammed, Shanghai Hydraulic station manufactor Check again after cleaning, otherwise the main control valve needs to be repaired.

As the structure and size of various hydraulic cylinders are different, the disassembly sequence is slightly different. Generally, drain the oil in the two chambers of the oil cylinder, remove the cylinder head, and finally remove the piston and piston rod. Shanghai Hydraulic station When disassembling the cylinder head of the hydraulic cylinder, special tools shall be used for the key or snap ring of the internal key type connection, and flat shovel is prohibited; Flange end caps must be pushed out with screws, and hammering or hard prying is not allowed. When it is difficult to draw out the piston and piston rod, do not force them out, Shanghai Hydraulic station manufactor The reason shall be found out before disassembly. Before and after unloading, try to create conditions to prevent the parts of the hydraulic cylinder from being polluted by the surrounding dust and impurities.

If the piston rod of the hydraulic cylinder is not treated in time after being pulled, the normal use will be affected if it is light, and the operation will not be possible if it is heavy. The repair methods we adopt are local polishing to repair light draw marks, welding and manual polishing to repair heavy draw marks. Shanghai Hydraulic station Through quenching and tempering treatment, the comprehensive mechanical properties of the cylinder piston rod with good strength and toughness matching were obtained. Shanghai Hydraulic station manufactor The purpose of surface hardening is to obtain high surface hardness to support the chromium plating layer on the surface, so as to improve the wear resistance and corrosion resistance of the piston rod.

How to install and fix the hydraulic cylinder? There are two common ways to fix the hydraulic cylinder: the first is the square hydraulic cylinder fixed on the B plate, and the hydraulic cylinder needs to be positioned on the B plate. The second is a round hydraulic cylinder fixed on the ejector plate. It should be noted that the thimble plate locking screw needs to be added next to the hydraulic cylinder, and the force at this position is large, Shanghai Hydraulic station Prevent tension deformation. Another point is to inscribe words on the hydraulic cylinder, and write down the stroke of the hydraulic cylinder for easy verification. To correctly install the sealing device at each position of the hydraulic cylinder: Shanghai Hydraulic station manufactor When installing the O-ring seal, pay attention to its installation direction to avoid oil leakage due to installation. Its lip should face the oil chamber with pressure.