How to deal with hydraulic clamping of hydraulic press?

Hydraulic valve is one of the key components in the hydraulic press, but also the most used components of the hydraulic system, when the oil passes through the hydraulic valve, the radial unbalanced force acting on the spool makes the spool stuck, called hydraulic clamping, what should be done?

Slight hydraulic clamping, making the hydraulic press friction resistance increases, serious will lead to hydraulic components action lag, when the hydraulic clamping resistance is greater than the spool moving power when the spool can not move, accelerate wear and reduce the service life, first of all, improve the production accuracy of the spool and valve hole, the roundness and taper of the spool allowable difference is 0.003-0.005mm, and should be with coning, The surface roughness of the spool should be less than 0.1, and the valve hole should be less than 0.2. With intermittent to be appropriate, too large easy to leak, too small is susceptible to thermal expansion stuck; If the accuracy of the spool permits, the cone can be worn, if the structure permits, the cone shoulder can be used, and the small end of the shoulder is toward the high pressure area, which is conducive to the radial alignment of the valve stem. Carefully remove the burrs on the shoulder of the core and the edge of the sink groove of the valve hole, remove the oxide skin of the heat treatment parts, and use the station equipment to prevent the parts from bumping during the rotation; Secondly, during the assembly process of the hydraulic press, it is necessary to prevent the parts from bumping, pay attention to cleaning to reduce the entry of particulate pollutants, and the pre-tightening force of each bolt should be appropriate to prevent the valve hole from deformation; Ensure the cleanliness of the hydraulic system and prevent the oil from being polluted; Finally, improve the casting quality of the valve body, reduce the residual stress of the heat treatment of the valve core, prevent bending deformation, for the combined directional valve, eliminate the influence of the flatness of the joint surface between the valve plates on the clamping, which can make the middle part of one of the surfaces low 1 ~ 2μm, which can reduce the deformation of the valve hole, and will not affect the sealing of the joint surface.

Four-column hydraulic press in the use of the process, the pipeline is inevitably blocked, after running for a period of time, each component or pipeline has a certain amount of dust accumulated, in order to ensure normal, so it must be cleaned regularly, before the operation must first determine the flushing circuit, according to the specific situation of the specific analysis.