Causes of leakage problem of Manifold Block electromagnetic reversing hydraulic valve
External leakage is a common failure of Manifold Block electromagnetic directional hydraulic valve, which mainly occurs in three places: (1) the bonding surface of electromagnet and valve body; (2) the joint surface of the solenoid valve and the installation bottom plate; (3) Thread joint of process plug or pipe valve oil port.
The main reasons for the external leakage of Manifold Block electromagnetic reversing hydraulic valve are as follows:
(1) The connecting screw is loose. When the screw is not tight enough, or the vibration of the machine, may lead to the loosening of the screw. In this case, just use the appropriate tools to tighten it. [Electromagnetic reversing hydraulic valve]
(2) Leakage of the sealing ring or failure of the sealing ring. Sealing ring failure has several manifestations: one is the appearance of rupture; Second, the local flattening; Third, corrosion damage; Fourth, the elasticity gets worse. The elimination method is to replace the new sealing ring.
(3) Oil pressure is too high. Excessive oil pressure can also lead to external leakage. At this time, you can read the pressure from the pressure gauge, to determine whether the pressure is too high, if the pressure is higher than the system pressure, the pressure is too high. Elimination method: through the pressure valve to set the system pressure.
(4) The installation surface is rough. Improper installation surface roughness may cause external leakage. Elimination method: grinding the mounting surface to make its roughness meet the product requirements, usually the valve mounting surface roughness is not greater than 0.8 micron. [Electromagnetic reversing hydraulic valve]
For the above four reasons, the order of inspection is: first look at the pressure gauge, then check whether the end cover is loose, finally open the valve, check the sealing ring, and measure the roughness of the installation surface. This sequence reflects the principle of easy to difficult, from the outside to the inside, to facilitate maintenance.
The main reasons for internal leakage of Manifold Block electromagnetic reversing hydraulic valve are as follows:
Although the internal leakage is not easy to find, but the large amount of internal leakage will lead to power loss, and then cause the system to heat up, and even abnormal action and other faults.
(1) The fit clearance between the spool and the valve hole is greater than the normal fit clearance due to wear and other reasons.
(2) There are burrs between the spool and the valve hole. This situation requires deburring. [Electromagnetic reversing hydraulic valve]
(3) The positioning size of both ends of the valve is not accurate (including the compression length of the spring), resulting in the leakage of the valve core displacement is not accurate.
(4) The working oil temperature is greater than 70℃, resulting in oil viscosity is not standard and leads to internal leakage, then the cooler is needed to cool the oil to between 15 and 55℃.