Electronic expansion valve

Abstract

The electronic expansion valve comprises a rotor assembly, a lead screw, a valve element assembly and a valve seat assembly, the valve element assembly can move in the axial direction of the lead screw relative to the valve seat assembly, one end of the lead screw is fixedly connected to the rotor assembly, the other end of the lead screw is connected with the valve element assembly, and the rotor assembly can drive the valve element assembly to move through the lead screw. A first valve port and a second valve port are formed in the side wall of the valve seat assembly, the electronic expansion valve is further provided with a first pre-tightening structure and / or a second pre-tightening structure, and when the lead screw drives the valve element assembly to block the first valve port, the second pre-tightening structure can apply acting force for pressing the first valve port to the valve element assembly; when the lead screw drives the valve element assembly to block the second valve port, the first pre-tightening structure can apply acting force for pressing the second valve port to the valve element assembly. According to the electronic expansion valve provided by the invention, the problem that the electronic expansion valve leaks due to the fact that a gap is easily generated at the sealing position between the valve element and the valve port part is solved.

Description

Technical Field

[0001] The present application relates to the field of valve body technology, and in particular to an electronic expansion valve. Background Art

[0002] In order to facilitate the switching of multiple flow paths, the existing electronic expansion valve is often provided with multiple valve ports, and the valve core is switched between different valve ports to achieve the flow of different flow paths. However, the electronic expansion valve with multiple valve ports in the prior art cannot ensure that the valve core and the valve port have good sealing performance when the valve port is closed. Summary of the invention

[0003] Based on this, it is necessary to provide an electronic expansion valve to solve the problem that a gap is easily generated at the seal between the valve core and the valve mouth, resulting in leakage of the electronic expansion valve.

[0004] The electronic expansion valve provided in the present application includes a rotor assembly, a screw rod, a valve core assembly and a valve seat assembly. The valve core assembly can move relative to the valve seat assembly along the axial direction of the screw rod. One end of the screw rod is fixedly connected to the rotor assembly, and the other end is connected to the valve core assembly. The rotor assembly can drive the valve core assembly to move through the screw rod. The valve seat assembly is provided with a first valve port and a second valve port. The electronic expansion valve also has a first pre-tightening structure and / or a second pre-tightening structure. When the screw rod drives the valve core assembly to block the first valve port, the second pre-tightening structure can apply a force to the valve core assembly to compress the first valve port; when the screw rod drives the valve core assembly to block the second valve port, the first pre-tightening structure can apply a force to the valve core assembly to compress the second valve port.

[0005] In one embodiment, the valve core assembly includes a first valve needle and a second valve needle, and the screw rod can drive the first valve needle to drive the second valve needle to move along its own axis toward the direction close to the rotor assembly so that the second valve needle closes the first valve port, and the screw rod can drive the first valve needle to drive the second valve needle to move along its own axis toward the direction away from the rotor assembly so that the second valve needle closes the second valve port.

[0006] In one embodiment, the first pre-tightening structure is a first elastic member, one end of the first elastic member is connected to the screw rod, and the other end is connected to the stop seat. The first elastic member is a compression elastic member so that the screw rod and the stop seat can be movably matched along the axial direction of the screw rod through the first elastic member.

[0007] In one embodiment, the first elastic member is a compression spring, and the first elastic member is sleeved on the outer side of the screw rod.

[0008] In one embodiment, the electronic expansion valve also includes a first limit member and a second limit member, one of the first limit member and the second limit member is fixedly connected to the stop seat, and the other is fixedly connected to the screw rod, and one end of the first elastic member is connected to the first limit member, and the other end is connected to the second limit member.

[0009] In one embodiment, one of the first limiting member and the second limiting member is a bearing member, and the other is a step structure formed on the outer wall of the screw rod or a step structure formed on the inner wall of the stop seat.

[0010] In one embodiment, the second pre-tightening structure is a third elastic member, one end of the third elastic member is connected to the first valve needle, and the other end is connected to the second valve needle. The third elastic member is a compression elastic member, so that the first valve needle and the second valve needle can be movably matched along the axial direction of the screw rod through the third elastic member.

[0011] In one embodiment, the third elastic member is a compression spring, and the third elastic member is sleeved on the outer side of a portion of the first valve needle, the second valve needle is sleeved on the outer side of a portion of the first valve needle, and the third elastic member is located between the first valve needle and the second valve needle.

[0012] In one embodiment, the electronic expansion valve also includes a third limit member and a fourth limit member, one of the third limit member and the fourth limit member is fixedly connected to the first valve needle, and the other is fixedly connected to the second valve needle, and one end of the third elastic member is connected to the third limit member, and the other end is connected to the fourth limit member.

[0013] In one embodiment, the electronic expansion valve also includes a third elastic sealing ring, which is clamped between the outer wall of the second valve needle and the inner wall of the valve seat assembly and is in a compressed state, so that the outer wall of the second valve needle can be sealed and cooperated with the valve seat assembly through the third elastic sealing ring.

[0014] In one of the embodiments, the stop seat sleeve is arranged on the outside of the screw rod, and the valve core assembly also includes a sliding nut. The end of the screw rod away from the rotor assembly is threadedly matched with the sliding nut. The sliding nut and the stop seat or the valve seat assembly are matched with each other through a limiting structure, so that the screw rod can drive the sliding nut to drive the valve core assembly to move along the axial direction of the screw rod to open or close the first valve port and the second valve port, and the limiting structure can prevent the sliding nut from rotating around the axis of the screw rod.

[0015] In one of the embodiments, a stop protrusion extending along the radial direction of the sliding nut is provided on the circumferential side of the sliding nut, and a guide groove extending along the axial direction of the valve is provided corresponding to the stop protrusion of the stop seat or the valve seat assembly. The end of the stop protrusion away from the sliding nut extends into the guide groove and can slide and cooperate with the guide groove along the axial direction of the valve, and the stop protrusion and the guide groove constitute a limiting structure.

[0016] Compared with the prior art, this can improve the pre-tightening force of the valve core assembly on the first valve port or the second valve port. Even if the valve core assembly is subjected to vibration, under the pre-tightening force of the first pre-tightening structure and / or the second pre-tightening structure, it is difficult to generate a gap between the valve core assembly and the first valve port. Similarly, it is difficult to generate a gap between the valve core assembly and the second valve port. Therefore, the sealing performance of the electronic expansion valve is greatly improved, and leakage of the electronic expansion valve is effectively prevented. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the conventional technology, the drawings required for use in the embodiments or the conventional technology descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0018] Figure 1 A schematic diagram of the structure of an electronic expansion valve according to an embodiment of the present application;

[0019] Figure 2 for Figure 1 A partial structural schematic diagram of an electronic expansion valve is shown;

[0020] Figure 3 A cross-sectional view of an electronic expansion valve according to another embodiment of the present application;

[0021] Figure 4 A cross-sectional view of an electronic expansion valve according to another embodiment of the present application;

[0022] Figure 5 A cross-sectional view of an electronic expansion valve according to another embodiment of the present application.

[0023] : Figure numerals: 100, rotor assembly; 200, screw rod; 220, first limit member; 230, second limit member; 240, first rod body step; 300, valve core assembly; 310, sliding nut; 311, anti-rotation protrusion; 321, first valve needle; 3212, first needle body step; 322, second valve needle; 400, valve seat assembly; 431, first interface; 432, second interface; 440, first valve port; 450, second valve port; 480, third elastic sealing ring; 510, stop seat; 515, guide groove; 610, first elastic member; 630, third elastic member; 660, third limit member; 670, fourth limit member; 800, housing; 900, stator assembly. DETAILED DESCRIPTION

[0024] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0025] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of this application, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0026] In this application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0027] In the present application, unless otherwise clearly specified and limited, a first feature being “above” or “below” a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being “above”, “above”, and “above” a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being “below”, “below”, and “below” a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0028] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used herein are for illustrative purposes only and are not intended to be the only implementation method.

[0029] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0030] See also Figure 1-Figure 5 In one embodiment, the electronic expansion valve includes a rotor assembly 100, a screw rod 200, a valve core assembly 300 and a valve seat assembly 400. The valve core assembly 300 can move relative to the valve seat assembly 400 along the axial direction of the screw rod 200, one end of the screw rod 200 is fixedly connected to the rotor assembly 100, and the other end is connected to the valve core assembly 300, and the rotor assembly 100 can drive the valve core assembly 300 to move through the screw rod 200.

[0031] The side wall of the valve seat assembly 400 is provided with a first valve port 440 and a second valve port 450. The electronic expansion valve also has a first pre-tightening structure and / or a second pre-tightening structure. When the screw rod 200 drives the valve core assembly 300 to block the first valve port 440, the second pre-tightening structure can apply a force to the valve core assembly 300 to press the first valve port 440; when the screw rod 200 drives the valve core assembly 300 to block the second valve port 450, the first pre-tightening structure can apply a force to the valve core assembly 300 to press the second valve port 450.

[0032] In this way, the pre-tightening force of the valve core assembly 300 on the first valve port 440 or the second valve port 450 can be increased, thereby improving the sealing performance of the electronic expansion valve.

[0033] Further, in one embodiment, the valve core assembly 300 includes a first valve needle 321 and a second valve needle 322, and the screw rod 200 can drive the first valve needle 321 to drive the second valve needle 322 to move along its own axis toward the direction close to the rotor assembly 100. Specifically, the electronic expansion valve also includes a stopper 510 connected to the valve seat assembly 400, and the stopper 510 is sleeved outside the screw rod 200. The valve core assembly 300 also includes a sliding nut 310, a first valve needle 321 and a second valve needle 322. The end of the screw rod 200 away from the rotor assembly 100 is threadedly matched with the sliding nut 310, and the sliding nut 310 and the stop seat 510 are slidably matched along the axial direction of the screw rod 200. The rotor assembly 100 is connected to the end of the screw rod 200 away from the sliding nut 310, and the screw rod 200 can drive the sliding nut 310 to drive the second valve needle 322 to move along its own axis toward the rotor assembly 100 through the first valve needle 321, so that the second valve needle 322 closes the first valve port 440, and the screw rod 200 can drive the sliding nut 310 to drive the second valve needle 322 to move along its own axis toward the direction away from the rotor assembly 100 through the first valve needle 321, so that the second valve needle 322 closes the second valve port 450.

[0034] The sliding nut 310 and the stop seat 510 or the valve seat assembly 400 cooperate with each other through a limiting structure, so that the screw rod 200 can drive the sliding nut 310 to drive the valve core assembly 300 to move along the axial direction of the screw rod 200 to open or close the first valve port 440 and the second valve port 450, and the limiting structure can prevent the sliding nut 310 from rotating around the axis of the screw rod 200.

[0035] It should be noted that the working principle of the sliding nut 310 is as follows. Specifically, the circumferential side of the sliding nut 310 is provided with a rotation-stopping protrusion 311 extending along its own radial direction, and the stop seat 510 or the valve seat assembly 400 is provided with a guide groove 515 extending along its own axial direction corresponding to the rotation-stopping protrusion 311. The end of the rotation-stopping protrusion 311 away from the sliding nut 310 extends into the guide groove 515 and can slide with the guide groove 515 along the axial direction of the stop seat 510, so that the sliding nut 310 and the stop seat 510 slide along the axial direction of the stop seat 510. In addition, the rotation-stopping protrusion 311 and the guide groove 515 constitute a limiting structure.

[0036] Furthermore, in one embodiment, the first pre-tightening structure is a first elastic member 610, one end of the first elastic member 610 is connected to the screw rod 200, and the other end is connected to the stop seat 510, and the connection here includes abutment. The first elastic member 610 is a compression elastic member, so that the screw rod 200 and the stop seat 510 can be movably matched along the axial direction of the screw rod 200 through the first elastic member 610.

[0037] Furthermore, in one embodiment, the second pre-tightening structure is a third elastic member 630, one end of the third elastic member 630 is connected to the first valve needle 321, and the other end is connected to the second valve needle 322, and the connection here includes abutment. The third elastic member 630 is a compression elastic member, so that the first valve needle 321 and the second valve needle 322 can be movably matched along the axial direction of the screw rod 200 through the third elastic member 630.

[0038] Specifically, the first interface 431 and the second interface 432 are distributed along the axial direction of the valve seat assembly 400 , and the first valve port 440 is disposed between the first interface 431 and the second interface 432 , and the second valve port 450 is disposed on a side of the second interface 432 away from the first interface 431 .

[0039] Such a configuration defines that when the rotor assembly 100 rotates along a preset direction and the screw rod 200 drives the valve core assembly 300 to move to a first preset position toward the direction close to the rotor assembly 100 , the valve core assembly 300 can close the first valve port 440 and the second interface 432 is connected to the second valve port 450 .

[0040] When the valve core assembly 300 moves to the first preset position and the rotor assembly 100 continues to rotate along the preset direction, the second valve needle 322 cannot continue to move. Since the first valve needle 321 and the second valve needle 322 can cooperate along the axial direction of the screw rod 200 through the third elastic member 630, at this time, the screw rod 200 and the rotor assembly 100 drive the first valve needle 321 to disengage from the second valve needle 322 and move in a direction away from the first valve port 440. In addition, during the movement of the screw rod 200, the first valve needle 321 is driven to squeeze the third elastic member 630, so that the third elastic member 630 generates an elastic force on the second valve needle 322. The elastic force can drive the second valve needle 322 to further squeeze the first valve port 440, so that the second valve needle 322 generates a pre-tightening force on the first valve port 440, thereby improving the sealing between the first valve port 440 and the second valve needle 322.

[0041] It is defined that when the rotor assembly 100 rotates in a direction opposite to the preset direction and the screw rod 200 drives the valve core assembly 300 to move to a second preset position in a direction away from the rotor assembly 100, the valve core assembly 300 can close the second valve port 450, and the first interface 431 is connected to the second interface 432 through the first valve port 440.

[0042] When the valve core assembly 300 moves to the second preset position and the rotor assembly 100 continues to rotate in the direction opposite to the preset direction, the first valve needle 321 and the second valve needle 322 cannot move further. Since the screw rod 200 and the valve seat assembly 400 can cooperate along the axial direction of the screw rod 200 through the first elastic member 610, the screw rod 200 and the rotor assembly 100 move in a direction away from the second valve port 450, and the first elastic member 610 is squeezed during the movement of the screw rod 200. Under the push of the reaction force, the first elastic member 610 generates an elastic force on the screw rod 200, and the elastic force can drive the screw rod 200 to drive the valve core assembly 300 to further squeeze the second valve port 450, so as to generate a pre-tightening force on the second valve port 450, thereby improving the sealing between the second valve port 450 and the second valve needle 322.

[0043] It should be noted that the electronic expansion valve further includes a housing 800 and a stator assembly 900. The housing 800 is covered on the outside of the rotor assembly 100, part of the lead screw 200 and part of the valve core assembly 300 and welded to the valve seat. The stator assembly 900 is sleeved on the outside of the housing 800, and the stator assembly 900 can drive the rotor assembly 100 to rotate.

[0044] Furthermore, in one embodiment, the first elastic member 610 is a compression spring, and the first elastic member 610 is sleeved on the outer side of the screw rod 200 .

[0045] In this way, the processing difficulty of the first elastic member 610 is significantly reduced, and the assembly difficulty of the first elastic member 610 and the screw rod 200 is reduced.

[0046] Similarly, in one embodiment, the third elastic member 630 is a compression spring, and the third elastic member 630 is sleeved on the outer side of a portion of the first valve needle 321, the second valve needle 322 is sleeved on the outer side of a portion of the first valve needle 321, the third elastic member 630 is located inside the second valve needle 322, and the third elastic member 630 is located between the first valve needle 321 and the second valve needle 322.

[0047] In this way, the difficulty of processing the third elastic member 630 is significantly reduced, and the difficulty of assembling the third elastic member 630 is reduced.

[0048] In one embodiment, the electronic expansion valve also includes a first limit member 220 and a second limit member 230, one of the first limit member 220 and the second limit member 230 is fixedly connected to the stop seat 510, and the other is fixedly connected to the screw rod 200, and one end of the first elastic member 610 is connected to the first limit member 220, and the other end is connected to the second limit member 230.

[0049] Further, in one embodiment, one of the first limiting member 220 and the second limiting member 230 is a bearing member, and the other is a step structure formed on the outer wall of the screw rod 200 or a step structure formed on the inner wall of the stop seat 510 .

[0050] In this way, the coaxiality of the screw rod 200 and the stop seat 510 can be improved by the first limiting member 220 or the second limiting member 230 , and the degree of wear of the screw rod 200 and the stop seat 510 can be significantly reduced.

[0051] Specifically, in one embodiment, the first stopper 220 is a bearing member, and the outer ring of the bearing of the first stopper 220 is fixedly connected to the stopper seat 510, the inner ring of the bearing of the first stopper 220 and the outer wall of the screw rod 200 are movably matched along the axial direction of the screw rod 200, and the screw rod 200 can drive the inner ring of the bearing of the first stopper 220 to rotate synchronously. The second stopper 230 is a first rod body step 240 formed on the outer wall of the screw rod 200 and is fixedly connected to the outer wall of the screw rod 200. In addition, one end of the first elastic member 610 abuts against the inner ring of the bearing of the first stopper 220, and the other end abuts against the second stopper 230.

[0052] Since the screw rod 200 can drive the inner ring of the bearing of the first limit member 220 to rotate synchronously, and the second limit member 230 is a first rod body step 240 formed by the outer wall of the screw rod 200 and fixedly connected to the outer wall of the screw rod 200, both ends of the first elastic member 610 can rotate synchronously with the screw rod 200. Such a configuration greatly reduces the wear between the first elastic member 610, the screw rod 200 and the valve seat assembly 400, thereby improving the service life of the electronic expansion valve.

[0053] In another embodiment, the first stopper 220 is a bearing member, and the inner ring of the bearing of the first stopper 220 is fixedly connected to the screw rod 200, the outer ring of the bearing of the first stopper 220 and the outer wall of the stopper 510 are movably matched along the axial direction of the stopper 510, and the stopper 510 can limit the circumferential rotation of the outer ring of the bearing of the first stopper 220. The second stopper 230 is fixedly connected to the stopper 510. In addition, one end of the first elastic member 610 abuts against the outer ring of the bearing of the first stopper 220, and the other end abuts against the second stopper 230.

[0054] Since the stop seat 510 can limit the circumferential rotation of the outer ring of the bearing of the first limit member 220, and the second limit member 230 is fixedly connected to the stop seat 510, the two ends of the first elastic member 610 can remain in a non-rotating state along with the stop seat 510. Such a setting also greatly reduces the wear between the first elastic member 610, the screw rod 200 and the stop seat 510, thereby increasing the service life of the electronic expansion valve.

[0055] In one embodiment, the electronic expansion valve also includes a third limit member 660 and a fourth limit member 670, one of the third limit member 660 and the fourth limit member 670 is fixedly connected to the first valve needle 321, and the other is fixedly connected to the second valve needle 322, and one end of the third elastic member 630 is connected to the third limit member 660, and the other end is connected to the fourth limit member 670.

[0056] In one embodiment, the fourth limiting member 670 is a first needle body step 3212 formed on the outer wall of the first valve needle 321 and is fixedly connected to the outer wall of the first valve needle 321 .

[0057] Further, in one embodiment, one end of the first needle body step 3212 away from the outer wall of the first valve needle 321 cooperates with the inner wall of the second valve needle 322 along the axial guide of the second valve needle 322 .

[0058] In one embodiment, the electronic expansion valve also includes a third elastic sealing ring 480, which is clamped between the outer wall of the second valve needle 322 and the inner wall of the valve seat assembly 400 and is in a compressed state, so that the outer wall of the second valve needle 322 can be sealed and cooperated with the valve seat assembly 400 through the third elastic sealing ring 480.

[0059] In this way, the guiding cooperation between the second valve needle 322 and the valve seat assembly 400 can be achieved through the third elastic sealing ring 480, and the coaxiality of the second valve needle 322 and the valve seat assembly 400 can be ensured.

[0060] The electronic expansion valve further includes a stator assembly 900 , which is sleeved on the outer side of the housing 800 , and the stator assembly 900 can drive the rotor assembly 100 to rotate.

[0061] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0062] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the patent application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the scope of patent protection of the present application shall be subject to the attached claims.

Claims

1. An electronic expansion valve, characterized in that: The invention comprises a rotor assembly (100), a screw rod (200), a valve core assembly (300) and a valve seat assembly (400); the valve core assembly (300) can move relative to the valve seat assembly (400) along the axial direction of the screw rod (200); one end of the screw rod (200) is fixedly connected to the rotor assembly (100), and the other end is connected to the valve core assembly (300); and the rotor assembly (100) can drive the valve core assembly (300) to move through the screw rod (200); The valve seat assembly (400) is provided with a first valve port (440) and a second valve port (450), and the electronic expansion valve also has a first pre-tightening structure and / or a second pre-tightening structure. When the screw rod (200) drives the valve core assembly (300) to block the first valve port (440), the second pre-tightening structure can apply a force to the valve core assembly (300) to compress the first valve port (440); when the screw rod (200) drives the valve core assembly (300) to block the second valve port (450), the first pre-tightening structure can apply a force to the valve core assembly (300) to compress the second valve port (450).

2. The electronic expansion valve according to claim 1, characterized in that: The valve core assembly (300) includes a first valve needle (321) and a second valve needle (322); the screw rod (200) is capable of driving the first valve needle (321) to drive the second valve needle (322) to move along its own axis toward the direction close to the rotor assembly (100), so that the second valve needle (322) closes the first valve port (440); and the screw rod (200) is capable of driving the first valve needle (321) to drive the second valve needle (322) to move along its own axis toward the direction away from the rotor assembly (100), so that the second valve needle (322) closes the second valve port (450).

3. The electronic expansion valve according to claim 2, characterized in that: It also includes a stop seat (510) connected to the valve seat assembly (400), and the first pre-tightening structure is a first elastic member (610), one end of the first elastic member (610) is connected to the screw rod (200), and the other end is connected to the stop seat (510), and the first elastic member (610) is a compression elastic member, so that the screw rod (200) and the stop seat (510) can be movably matched along the axial direction of the screw rod (200) through the first elastic member (610).

4. The electronic expansion valve according to claim 3, characterized in that: The first elastic member (610) is a compression spring, and the first elastic member (610) is sleeved on the outer side of the screw rod (200).

5. The electronic expansion valve according to claim 3, characterized in that: It also includes a first limiting member (220) and a second limiting member (230), one of the first limiting member (220) and the second limiting member (230) being fixedly connected to the stop seat (510), and the other being fixedly connected to the screw rod (200), and one end of the first elastic member (610) being connected to the first limiting member (220), and the other end being connected to the second limiting member (230).

6. The electronic expansion valve according to claim 5, characterized in that: One of the first limiting member (220) and the second limiting member (230) is a bearing member, and the other is a step structure formed on the outer wall of the screw rod (200) or a step structure formed on the inner wall of the stop seat (510).

7. The electronic expansion valve according to claim 2, characterized in that: The second pre-tightening structure is a third elastic member (630), one end of the third elastic member (630) is connected to the first valve needle (321), and the other end is connected to the second valve needle (322), and the third elastic member (630) is a compression elastic member, so that the first valve needle (321) and the second valve needle (322) can cooperate along the axial direction of the screw rod (200) through the third elastic member (630).

8. The electronic expansion valve according to claim 7, characterized in that: The third elastic member (630) is a compression spring, and the third elastic member (630) is sleeved on the outer side of a portion of the first valve needle (321), and the second valve needle (322) is sleeved on the outer side of a portion of the first valve needle (321), and the third elastic member (630) is located between the first valve needle (321) and the second valve needle (322).

9. The electronic expansion valve according to claim 7, characterized in that: It also includes a third limit member (660) and a fourth limit member (670), one of the third limit member (660) and the fourth limit member (670) is fixedly connected to the first valve needle (321), and the other is fixedly connected to the second valve needle (322), and one end of the third elastic member (630) is connected to the third limit member (660), and the other end is connected to the fourth limit member (670).

10. The electronic expansion valve according to claim 2, characterized in that: It also includes a third elastic sealing ring (480), which is clamped between the outer wall of the second valve needle (322) and the inner wall of the valve seat assembly (400) and is in a compressed state, so that the outer wall of the second valve needle (322) can cooperate with the valve seat assembly (400) in a sealing manner through the third elastic sealing ring (480).

11. The electronic expansion valve according to claim 3, characterized in that: The stop seat (510) is sleeved on the outside of the screw rod (200), and the valve core assembly (300) further includes a sliding nut (310). One end of the screw rod (200) away from the rotor assembly (100) is threadedly matched with the sliding nut (310). The sliding nut (310) and the stop seat (510) or the valve seat assembly (400) are matched through a limiting structure, so that the screw rod (200) can drive the sliding nut (310) to drive the valve core assembly (300) to move along the axial direction of the screw rod (200) to open or close the first valve port (440) and the second valve port (450), and the limiting structure can prevent the sliding nut (310) from rotating around the axis of the screw rod (200).

12. The electronic expansion valve according to claim 11, characterized in that: The circumferential side of the sliding nut (310) is provided with a stop protrusion (311) extending along its own radial direction, and the stop seat (510) or the valve seat assembly (400) is provided with a guide groove (515) extending along the valve axis corresponding to the stop protrusion (311), and the end of the stop protrusion (311) away from the sliding nut (310) extends into the guide groove (515) and can slide with the guide groove (515) along the valve axis, and the stop protrusion (311) and the guide groove (515) constitute the limiting structure.

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