Trade-Off of the Clearance at the Control Plunger Section of a Solenoid Valve

Aiming at block failure of a type of solenoid valve, the clearance at the control plunger section was trade-off, and the purpose is to solve the block while not causing over leakage of the whole valve. According to the analysis of the internal leakage channel of the solenoid valve, it is known that there is no leakage in the clearance at the control plunger section under the power-off condition, and the leakage through the clearance is far less than the allowable value when the power is turned on, that is, the clearance can be increased to eliminate the jam. Within the allowable range of leakage, calculated according to the annular gap flow formula, when the eccentricity of the control plunger in the sleeve takes the extreme values 0 and 1, the unilateral maximum allowable values of the clearance are 6.3 μm and 4.6 μm respectively. According to the estimation of the leakage test results, the eccentricity of the control plunger in the sleeve is 0.42, and the unilateral maximum allowable value of the clearance is 5.8 μm. By increasing the clearance of the control plunger section, the block failure of the solenoid valve is eliminated, and no over-leakage occurs.