Electric valve

Abstract

An electric valve comprises a valve body assembly, a nut assembly, a valve needle lead screw assembly and a rotor assembly; the valve body assembly comprises a valve body and a valve core seat which is welded on the valve body; the nut assembly comprises a plastic nut and a connecting piece, wherein the plastic nut is used for installing the valve needle lead screw assembly and the connecting piece is connected with the plastic nut. The electric valve is characterized in that the nut assembly is provided with a circumferential positioning portion and an axial positioning portion, wherein the circumferential positioning portion is matched with the valve body assembly so as to limit the circumferential rotation of the nut assembly and the axial positioning portion is used for limiting the axial movement of the nut assembly; the valve body is provided with a riveting pressure portion which is matched with the axial positioning portion; the nut assembly is fixed on the valve body assembly through the riveting pressure. According to the electric valve, the coaxiality of a valve needle and the valve core seat is high and the operation of the valve need is reliable.

Description

technical field [0001] The invention relates to the technical field of control valves, in particular to an electric valve for regulating fluid flow. Background technique [0002] In air conditioners, refrigerators, heat pump water heaters and various refrigeration and heating equipment, electric valves are usually used to regulate the flow of fluid. [0003] The electric valve usually includes a valve body assembly, a nut assembly, a valve needle screw assembly, and a rotor assembly. The valve body assembly usually includes a valve core seat, a valve seat and a connecting pipe. The tube is usually welded together to form the valve seat assembly, and the valve needle of the valve needle screw assembly is installed in the nut of the nut assembly. [0004] The patent document (JP-A-2010-25932) discloses an electric valve. The nut of the nut assembly is fixed in the guide sleeve, the guide sleeve is fixed on the valve seat, and the valve needle needs to be fixed in the valve po...

AI Technical Summary

Problems solved by technology

[0004] The patent document (JP-A-2010-25932) discloses an electric valve. The nut of the nut assembly is fixed in the guide sleeve, the guide sleeve is fixed on the valve seat, and the valve needle needs to be fixed in the valve port of the valve seat. Therefore, the coaxiality between the valve seat and the nut is highly required. The above-mentioned electric valve needs to be indirectly controlled through multiple assembly processes to ensure the coaxiality between the valve core seat and the nut, and the coaxiality between the valve seat and the nut is affected by the nut, guide Affected by the processing accuracy of sleeve, valve seat, valve needle and other parts, the coaxiality is not easy to guarantee. If the valve core seat and the nut are not in the same axis, it is easy to appear that the valve needle and the valve port are not in the same axis, which will cause the valve The sealing of the port is not tight or the valve port is eccentrically worn, which makes the reliability of the action of the electric valve low and the service life of the electric valve is also short.

In addition, it has become a development trend in this field to replace metal materials with plastic materials. In the above-mentioned electric valve, if the nut is made of plastic, it is not easy to ensure the connection strength and reliability of the connection between the nut and the guide sleeve only through interference fit. Low, so that the nut can not be made of plastic, but still have to use expensive metal material, so that the processing cost of the electric valve is relatively high

[0005] In order to improve the technology, in another previously declared patent CN201180049867.0, the valve body assembly and the plastic nut are welded together to provide reliability, but the welding process will cause thermal deformation of the plastic nut, which will affect the guide fit in the Valve pin screw assembly in nut cavity controls operating accuracy

On the other hand, if there are defective products during the welding process, all semi-finished parts cannot be reworked and scrapped, resulting in high costs

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