Switching mechanism for large-flow overflow safety valve

Abstract

The invention discloses a switching mechanism for a large-flow overflow safety valve. The switching mechanism comprises a liquid inlet joint with a liquid inlet hole and further comprises a valve element assembly which can move relative to the liquid inlet joint and is used for controlling opening and closing of the liquid inlet hole, the valve element assembly comprises a nut and a valve pad arranged in the nut, and the valve pad is provided with a seal surface used for being matched with the liquid inlet joint, wherein a conical surface is adopted as the seal surface. According to the switching mechanism for the valve element assembly, by arranging the movable valve element assembly to be matched with the liquid inlet joint, the valve element assembly can be used for controlling connection and disconnection of an oil way from the liquid inlet hole to a liquid outlet hole, large-flow overflowing can be achieved when the valve element assembly is far away from the liquid inlet joint, the safety valve flow is greatly increased, axial displacement of the valve element assembly can be reduced through short-time quick overflowing, axial deformation of a reset spring can be reduced through axial displacement reduction of the valve element assembly, and pressure fluctuation can be reduced finally.

Description

technical field [0001] The invention belongs to coal mine fully mechanized mining hydraulic support, in particular, the invention relates to an opening and closing mechanism of a large-flow overflow safety valve. Background technique [0002] With the large-scale implementation and development of coal mine fully mechanized mining hydraulic supports, fully mechanized mining work has more and more stringent requirements for hydraulic supports, so there are further requirements for the safety valve of the hydraulic cylinder of the protection support, especially for the safety valve There are further requirements for the service life and reliability of the hydraulic support. When the pressure from the top of the hydraulic support causes passive force, whether the safety valve can unload in a short time, fully and stably under the condition of high pressure directly affects the service life of the support. and support security. It will not only damage seals, pipes and hydraulic ...

AI Technical Summary

Problems solved by technology

[0004] The overflow channel of the existing safety valve adopts the liquid passage hole arranged around the side wall of the valve core. The diameter of the liquid passage hole is small, resulting in small discharge flow and large flow loss. The seat bears the axial force exerted by the return spring, which leads to poor stress on the valve core and large pressure fluctuations during the working process, which leads to generally unsatisfactory closing pressure of the safety valve, and eventually leads to failure of the hydraulic components connected to the safety valve. Such as excessive loss of oil in the high-pressure cylinder, resulting in waste

The sealing effect between the spool and the valve sleeve is not ideal, and the processing accuracy of the groove on the surface of the spool for installing the seal is not easy to control

In addition, the spring cavity inside the valve housing is in an open state, and the dustproof, waterproof and rustproof effects are poor, which reduces the service life of the safety valve

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