Electronic expansion valve

Abstract

The invention discloses an electronic expansion valve comprising a valve rod capable of axially moving along a valve cavity and a reset elastic member tensioned along with the movement of the valve rod; the upper end of the reset elastic member is positioned on a valve body through a positioning part, a spacing part is arranged in the valve cavity; an inner wall of the valve cavity is provided with a radial lug boss, the spacing part is arranged on the lug boss, and the spacing part is provided with an axial passage allowing the valve rod to pass through; a radial convex edge located at the lower part of the axial passage is arranged on the valve rod, the minimum dimension of the axial passage in the radial direction is less than the maximum dimension of the convex edge in the radial direction; a supporting piece is further arranged in the valve cavity and is supported between the spacing part and the positioning part. When the valve rod is moved upwards to the maximum valve opening position or slightly higher than the position, the valve rod cannot continuously move upwards for the leaning of the spacing part; when the coil is dismounted and changed or a valve needle part needs to be separated from the other parts at the upper part, the valve rod cannot largely move upwards or excessively compress the reset elastic member, so that the service life of the elastic member is prolonged.

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 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 and a thread pair structure 3 located in the nut 4, a reset elastic member 7 located in the valve seat 8, and a valve Core parts such as needle part 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 expansion valve, which drives the gear reducer 2 ...

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. In fact, the valve stem in the valve needle part moves upward substantially. Therefore, During the upward movement of the valve needle part 9, the return elastic part 7 will be over-compressed, and its reset ability will be lost or reduced, thus affecting the service life of the return elastic part 7

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