What principles and steps should be followed in the disassembly and installation of the medium pressure cylinder of the block press

　　Usually when preparing to handle a hydraulic cylinder in a block press, try to create conditions to prevent the parts of the hydraulic cylinder from being contaminated by surrounding dust and impurities. For example, disassembly should be carried out in a clean environment as far as possible; After disassembly, all parts should be covered with plastic sheets, not cotton or other work cloths. For more details, follow these four steps:

　　1. Before disassembling the hydraulic cylinder in the block press, the hydraulic circuit should be relieved. Otherwise, when the tubing joint connected with the cylinder is loosened, the high-pressure oil in the circuit will quickly spray out. Hydraulic circuit pressure relief should first loosen the relief valve and other places of the hand wheel or pressure screw, so that the pressure oil unloading, and then cut off the power supply or cut off the power source, so that the hydraulic device stop running.

　　2, disassembly should prevent damage to the piston rod top thread, oil thread and piston rod surface, cylinder liner inner wall, etc. In order to prevent the piston rod and other slender parts from bending or deformation, the wood support should be balanced when placed.

　　3. When disassembling the cylinder in the equipment, it should be carried out in sequence. Because the structure and size of various hydraulic cylinders are not the same, the disassembly sequence is also slightly different. Generally, the oil in the two cavities of the cylinder should be discharged, and then the cylinder head should be removed, and finally the piston and piston rod should be removed. When removing the cylinder head of the hydraulic cylinder, special tools should be used for the card key or the ring connected by the internal card key, and flat shovel is prohibited; For flanged end caps, they must be pushed out with screws. Hammering or hard prying is not allowed. When the piston and piston rod are difficult to pull out, they can not be forced out, and the cause should be found out before disassembly.

　　4, the cylinder should be carefully checked after removal to determine which parts can continue to be used, which parts can be repaired and reused, and which parts must be replaced.

　　When the treated or repaired hydraulic cylinder is ready to be installed on the block press equipment, we should also follow the following four installation steps:

　　1. The surrounding environment of the press should be clean. The hydraulic cylinder must be sealed to prevent contamination. Pipelines and fuel tanks should be cleaned to prevent falling off the oxide sheet and other debris. Clean with lint-free cloth or special paper. Twine and adhesives should not be used as sealing materials. Hydraulic oil according to the design requirements, pay attention to the change of oil temperature and oil pressure. When there is no load, unscrew the exhaust bolt for exhaust.

　　2, the pipeline link in the press equipment shall not be relaxed, the hydraulic cylinder base must have sufficient stiffness, otherwise the cylinder is bowed upward when pressurized, so that the piston rod is bent.

　　3, before installing the hydraulic cylinder to the system, the parameters on the hydraulic cylinder label should be compared with the parameters at the time of ordering.

　　4, install the hydraulic cylinder seal gland screw, the degree of tightening to ensure that the piston in the full stroke of the flexible movement, no block and uneven weight phenomenon is appropriate, screw too tight, will increase resistance, accelerate wear; Too loose will cause oil leakage.

　　Finally, the author still needs to conclude: whether in the installation or removal of the hydraulic cylinder in the press, it is forbidden to use the hammer to strike the cylinder liner and the piston rod surface. If the cylinder hole and piston rod surface is damaged, do not use, the clearance between the guide sleeve and the ship's hydraulic cylinder must meet the requirements.