Direct-acting overflow valve

Abstract

The invention discloses a direct-acting overflow valve. Main and secondary valve elements are arranged in a valve sleeve; a spring is arranged in an inner cavity of the main valve element; and the other end is positioned on a spring base. The main valve element is in threaded connection with the secondary valve element; a large-diameter cylinder of the secondary valve element is positioned in the main valve element; one end of an adjusting screw rod is positioned in a small-diameter cylinder; a spring base for connecting the secondary valve element with the adjusting screw rod and coating a shaft shoulder of the adjusting screw rod is arranged at the shaft shoulder of the end part of the adjusting screw rod; the adjusting screw rod is provided with an external thread, is in threaded connection with a center screw hole of the locking nut, and extends out of the locking nut; an inner screw hole is formed in the end top; and the locking nut is in threaded connection with the valve sleeve. The direct-acting overflow valve optimizes the stress state in movement of the main valve elements I and II to reduce the spring rigidity; a peripheral damping hole in the main valve element I enables the main valve elements I and II to reach high opening and closing moment motion stability; the impact and the vibration of the direct-acting overflow valve are effectively reduced; the pressure adjusting deviation is low; and the pressure control precision is high.

Description

technical field [0001] The invention relates to a hydraulic component, especially a direct-acting relief valve. Background technique [0002] The direct acting relief valve is the pressure control element in the hydraulic system. In the speed regulating circuit of the fixed pump, the direct-acting overflow valve is used to control the outlet pressure of the hydraulic pump, overflow the excess flow, and play the role of stabilizing the overflow; in the speed regulating circuit of the variable pump, the direct-acting overflow valve is used for normal operation The valve is in the closed state, and the set pressure is higher than the system working pressure, which acts as overload protection. According to the structure of the main valve core, the direct-acting relief valve can be divided into slide valve type, cone valve type and ball valve type, etc., but the working principle is basically the same. The gap enters the bottom of the damping piston and directly acts on the are...

AI Technical Summary

Problems solved by technology

When the direct-acting relief valve is opened, the spring force is balanced with the pressure of the P chamber, so a high-rigidity spring must be matched in the high-pressure system, resulting in a large system pressure regulation deviation, a high slope of the pressure-flow characteristic curve, and low pressure regulation accuracy.

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