Stuck analysis and test verification of a double slide valve auxiliary valve

To solve the problem of stuck phenomenon for a double slide valve, the internal flow field of the slide valve and the force of key parts were analyzed by the fluid-structure interaction (FSI) simulation. The influence law of different inlet size and valve sleeve oil port structure on the flow field in the valve chamber and the radial force of the spool were summarized, and the range of overturning angle of the spring seat during the spool opening was obtained. The results show that the oil velocity and hydraulic impact can be reduced by increasing the size of the inlet port and the number of holes in the valve sleeve, as well as reducing the diameter of valve sleeve holes and the freedom of movement of the spring seat, so that the circumferential pressure distribution of spool is more uniform, and the balance of radial force of spool can be improved. Based on this, the valve structure was improved and verified through experiments. The experimental results show that after the oil inlet diameter of the double slide valve is changed to 8 mm, the number of valve sleeve holes is changed to 6, the diameter of valve sleeve holes to 4 mm, and canceling the contact form between the spool and the spring seat point, the spool is switched at least 600 times under two working conditions, and there is no scratch on the surface of the valve core. The improved dual slide valve fully meets the design requirements.