Fast hydraulic change-over valve

Abstract

The invention discloses a fast hydraulic change-over valve which comprises a valve body, a sleeve and a valve core; the valve core is arranged in the valve hole of the valve body; one end of the valve body is provided with an external thread and connected with the thread of the sleeve; the sleeve is provided with a spring cavity, the spring cavity is internally provided with a spring, and the spring is also arranged in the valve hole and contacted with the valve core; the wall of the valve body is provided with an oil inlet cavity, a working oil cavity and an returning cavity which are all communicated with the valve hole and arranged in sequence along the direction from the end provided with the external thread to the other end far away from the external thread; the valve core is provided with blind holes along the central axis of the valve core beginning from the end face opposite to the spring cavity; the shaft neck of the valve core is provided with radial holes communicated with the blind holes, the entrances of the blind holes are in thread connection with damping thread plugs, and the damping thread plugs are internally provided with throttle holes. The invention has the advantages that the valve core can be fast reset, and has short motion distance during resetting; the requirement on rigidity of the spring is low, and the valve core opening speed is accelerated; the volume of the control cavity is reduced, and the valve core has fast change-over speed; the structure is simple, the assembly and disassembly are convenient, and the assembly space is saved efficiently.

Description

technical field [0001] The invention relates to a hydraulic reversing valve, which belongs to the field of hydraulic control. Background technique [0002] Most traditional hydraulic directional valves use return springs for reset. For high-response applications, in order to speed up the reset speed of the spool of hydraulic directional valves, it is necessary to increase the spring stiffness of the return spring. However, increasing the stiffness of the return spring will increase the hydraulic pressure. The spring force that needs to be overcome when the hydraulic reversing valve is opened, thus slowing down the opening speed of the hydraulic reversing valve, so the opening and reset speeds of the traditional hydraulic reversing valve are often contradictory, and because the traditional hydraulic reversing valve When it is in the open position, the return spring is compressed to the limit position, so the valve core needs to move for a long empty stroke when the hydraulic ...

AI Technical Summary

Problems solved by technology

[0002] Most traditional hydraulic directional valves use return springs for reset. For high-response applications, in order to speed up the reset speed of the spool of hydraulic directional valves, it is necessary to increase the spring stiffness of the return spring. However, increasing the stiffness of the return spring will increase the hydraulic pressure. The spring force that needs to be overcome when the hydraulic reversing valve is opened, thus slowing down the opening speed of the hydraulic reversing valve, so the opening and reset speeds of the traditional hydraulic reversing valve are often contradictory, and because the traditional hydraulic reversing valve When it is in the open position, the return spring is compressed to the limit position, so the valve core needs to move for a long empty stroke when the hydraulic reversing valve is reset, resulting in a long reset time and slow reversing speed

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