Hydraulic valves work more or less internal leakage phenomenon, which is related to the structure and working principle of electromagnetic directional valve, a certain range of internal leakage is a normal phenomenon, can not be completely avoided. The working principle of the solenoid directional valve is that the electromagnet is energized to drive the push rod to produce relative movement of the spool, so as to open or close the corresponding oil hole.
Hydraulic valve manufacturer
The clearance between hydraulic valve body and spool is called fit precision. The matching precision needs to be strictly controlled within the precise value to ensure the stability of solenoid directional valve quality. Excessive internal leakage directly affects the working efficiency of the actuator of the hydraulic system, and easily causes the system misoperation and other faults.
The hydraulic valve clearance is not simply the pursuit of the more precise the better, but should be based on the requirements of the working condition, as well as the cost and other comprehensive consideration, choose the most appropriate scheme. As we all know, hydraulic oil in hydraulic system is easy to mix with small impurities and difficult to completely eliminate.
It is common practice to use a single filter screen in the tank to filter impurities. However, this relatively simple, low-cost filter has limited accuracy and cannot effectively filter fine impurities. The matching accuracy of the electromagnetic directional valve is higher than the filtering accuracy of the filter. Obviously, the valve spool is easily blocked by impurities that have not been filtered, resulting in the failure of the electromagnetic directional valve.
For high precision electromagnetic directional valve, it is usually recommended to use cotton core and other high precision filtration equipment, which will cause the cost of the whole system to increase. Therefore, the requirements of the internal leakage size of the solenoid valve should be flexibly mastered according to the actual work requirements.
