Electronic expansion valve

Abstract

The invention discloses an electronic expansion valve, comprising a drive mechanism, a transmission mechanism, a valve seat and a valve needle component, wherein the valve needle component is provided with a valve needle axially moving along the valve cavity of the electronic expansion valve to control the openness of a valve opening, a valve rod, and an elastic component for reset. The electronic expansion valve is characterized by further comprising a limit structure arranged in the valve cavity and provided with an axial channel, and the valve needle component is provided with a transversal flange; and the limit structure is located above the flange in the case that the valve needle component moves upwards until the valve opening has the maximum openness, and the minimum radial dimension of the axial channel is less than the maximum radial dimension of the flange. The valve needle component of the electronic expansion valve cannot continue to move upwards due to the resisting of the limit structure in case of moving upwards to the position where the valve opening is the largest or slightly higher, and the valve needle component cannot greatly move upwards to compress the elastic component for reset in excess in case of coil detachment and replacement and in the other cases of needing to separate the valve needle component from other components above, thus prolonging the service life of the elastic component.

Description

technical field [0001] The invention relates to the technical field of heating, ventilating and air conditioning, in particular to an electronic expansion valve. Background technique [0002] Electronic expansion valves are widely used in throttling expansion and flow regulation of fluids. [0003] Please refer to figure 1 , figure 1 It is a structural schematic diagram of a typical deceleration electronic expansion valve for inverter air conditioners. [0004] The electronic expansion valve mainly includes a permanent magnet stepping motor 1, a gear reducer 2 with three-stage reduction, a screw rod 5 located in the nut 4 and a thread pair structure 3, a bush 6 located in the valve seat 8, and a return elastic Core components such as component 7 and valve needle component 9. The specific working principle is as follows: the electronic controller of the air-conditioning system controls the forward and reverse rotation of the rotor of the stepping motor 1 of the electronic...

AI Technical Summary

Problems solved by technology

[0005] When there is a problem with the coil of the stepping motor 1 and it needs to be replaced, the valve body and the coil need to be separated. After the separation, the top of the bush 6 does not contact the screw rod 5, and the upward movement of the valve needle part 9 is no longer restricted. At this time, the system pressure of the refrigerant pipeline is relatively high, and under the action of the system pressure, the valve needle part 9 will move upward rapidly and substantially. Therefore, the upward movement of the valve needle part 9 will cause the reset elastic part 7 Excessive compression, loss or reduction of its reset ability, thereby affecting the service life of the reset elastic component 7

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