A New Type of Large Flow and Small Internal Leakage Direct-acting Relief Valve

Abstract

A novel large-flow and small-inner-leakage-flow direct-acting type overflow valve comprises a valve seat (1) and the like, wherein the valve seat (1) is mounted at one end of a casing (6), a valve core (5) is mounted in the casing (6), the small end of the valve core (5) is inserted in a blind hole in the middle of the valve seat (1), and the sealing of an end opening of the blind hole is realized through an injection mould (4) embedded in the valve core (5); the two ends of an adjusting spring (7) are connected with the large end of the valve core (5) and the large end of an adjusting screw rod (12) respectively; an end cover (9) is mounted at the other end of the casing (6); the adjusting screw rod (12) is mounted in the end cover (9), the large end of the adjusting screw rod (12) is clamped on one side of the end surface of the end cover (9), and the small end of the adjusting screw rod (12) extends out of a through hole in the end surface of the end cover (9); a locking nut (13) is mounted at the part, which extends out of the end cover (9), of the adjusting screw rod; and projecting structures are distributed on the side wall of the large end of the valve core (5) in a circumferential direction, and flow grooves (23) are formed among the projecting structures. The overflow valve provided by the invention is suitable for a hydraulic system with high working pressure, large oil flow and a low-viscosity fluid medium.

Description

technical field [0001] The invention relates to a direct-acting relief valve, which belongs to the technical field of pressure control valves. Background technique [0002] At present, some servo mechanisms of my country's launch vehicles often use overflow valves to keep the inlet pressure of the key components of the servo valve constant, so that the servo system has better control performance. Traditional large-flow relief valves often adopt a pilot-operated secondary structure, but the structure is complex and the dynamic response is slow. Although the existing relief valves also use annular grooves to increase the reverse jet force of the outflow medium, they all use rectangular cross-sections. The annular groove, and the structural size is not enough to play the role of diversion and reflection, the effect is limited, and the fluid medium cannot quickly enter the bottom of the valve core, which affects the response speed of the relief valve. In addition, it adopts a s...

AI Technical Summary

Problems solved by technology

Traditional large-flow relief valves often adopt a pilot-operated secondary structure, but the structure is complex and the dynamic response is slow. Although the existing relief valves also use annular grooves to increase the reverse jet force of the outflow medium, they all use rectangular cross-sections. The annular groove, and the structural size is not enough to play the role of diversion and reflection, the effect is limited, and the fluid medium cannot quickly enter the bottom of the valve core, which affects the response speed of the relief valve

In addition, it adopts a separate structure of the spring seat and the valve core. During the working process, the spring seat will be unstable, so that the fluid medium cannot always maintain the best jet angle state, and the effect is limited. Moreover, the spherical surface of the valve core of the separate structure and the contact with it often occur. The surface finish and cylindricity of the inner surface of the spring seat require high processing, otherwise there will be hysteresis, which will affect the closing effect of the valve core

[0003] In addition, the above-mentioned servo mechanism uses kerosene medium, which has strict requirements on internal leakage, while the traditional relief valve spool and valve seat are hard-sealed, and the leakage is relatively large. Poor, so applications are greatly limited

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