Improvement of Noise Reduction Structure of Direct-Acting Pressure Reducing Valve

As a key pressure control component of a hydraulic system, the noise of the direct-acting pressure reducing valve affects the working state of the system directly. However, the existing pressure reducing valves generally have the problem of excessive pure noise. In order to solve this problem, this study explored various structural combinations with the aim of improving the noise level of a direct-acting pressure reducing valve. Firstly, the flow field model of the direct-acting pressure reducing valve was established by using FEA (Finite Element Analysis), and the relationship between the flow field state and noise state was demonstrated through CFD (Computational Fluid Dynamics) simulation. Secondly, the position, number, and diameter of the oil holes on the valve spool were comprehensively analyzed, and the sound field analysis using LMS Virtual Lab was carried out. Finally, a prototype of the pressure reducing valve was manufactured, and the noise level before and after improvement was compared. The results showed that the effective sound pressure after improvement was reduced by 6.1% compared with that before at 50% of the opening, which verified the precision of the simulation model. The research results could provide a guideline for the design and improvement of direct-acting pressure reducing valves.