Electronic expansion valve

Abstract

The application relates to an electronic expansion valve, which comprises a rotor assembly, a screw rod, a valve core assembly and a valve seat assembly, the valve core assembly can move along the axial direction of the screw rod relative to the valve seat assembly, one end of the screw rod is fixedly connected to the rotor assembly, the other end is connected with the valve core assembly, and the rotor assembly can drive the valve core assembly to move through the screw rod. The side wall of the valve seat assembly is provided with a first valve port and a second valve port, and the electronic expansion valve further 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 exert an action force on the valve core assembly to press 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 exert an action force on the valve core assembly to press the second valve port. The electronic expansion valve provided by the application solves the problem that a gap is easily generated at the sealing position between the valve core and the valve port part, thereby causing the electronic expansion valve to leak.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of valve body, in particular to an electronic expansion valve. BACKGROUND

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

[0003] Therefore, it is necessary to provide an electronic expansion valve to solve the problem that gaps are easily generated between the valve core and the valve port, resulting in leakage of the electronic expansion valve.

[0004] The electronic expansion valve provided by the present application comprises a rotor assembly, a lead screw, a valve core assembly and a valve seat assembly. The valve core assembly can move along 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, and the other end is connected to the valve core assembly. The rotor assembly can drive the valve core assembly to move through the lead screw. 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 lead screw drives the valve core assembly to block the first valve port, the second pre-tightening structure can exert a force on the valve core assembly to press the first valve port. When the lead screw drives the valve core assembly to block the second valve port, the first pre-tightening structure can exert a force on the valve core assembly to press the second valve port.

[0005] In one embodiment, the valve core assembly comprises a first valve needle and a second valve needle. The lead screw can drive the first valve needle to move the second valve needle along its own axis towards the rotor assembly to close the first valve port. The lead screw can also drive the first valve needle to move the second valve needle along its own axis away from the rotor assembly to close 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 lead screw, and the other end is connected to a stop seat. The first elastic member is a compression elastic member, so that the lead screw and the stop seat can be movably connected through the first elastic member along the axial direction of the lead screw.

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

[0008] In one embodiment, the electronic expansion valve further comprises a first limiting member and a second limiting member. One of the first limiting member and the second limiting member is fixedly connected to the stop seat, and the other is fixedly connected to the lead screw. One end of the first elastic member is connected to the first limiting member, and the other end is connected to the second limiting member.

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

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

[0011] In one of the embodiments, the third elastic member is a compression spring, and the third elastic member is sleeved on the outer side of part of the first valve needle, the second valve needle is sleeved on the outer side of part 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 of the embodiments, the electronic expansion valve further comprises third and fourth limit members, one of which is fixedly connected to the first valve needle and the other of which is fixedly connected to the second valve needle, one end of the third elastic member is connected to the third limit member, and the other end of the third elastic member is connected to the fourth limit member.

[0013] In one of the embodiments, the electronic expansion valve further comprises 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 is movably fitted with the valve seat assembly through the third elastic sealing ring.

[0014] In one of the embodiments, the stop seat is sleeved on the outer side of the screw rod, the valve core assembly further comprises a sliding nut, one end of the screw rod away from the rotor assembly is threadedly connected with the sliding nut, and the sliding nut and the stop seat or the valve seat assembly are matched through the limit structure, so that the screw rod can drive the sliding nut to move the valve core assembly along the axial direction of the screw rod to open or close the first valve port and the second valve port, and the limit structure can prevent the sliding nut from rotating around the axis of the screw rod.

[0015] In one of the embodiments, the sliding nut is provided with a rotation-stopping protrusion extending along the radial direction of the sliding nut, the stop seat or the valve seat assembly is provided with a guide groove extending along the axial direction of the valve corresponding to the rotation-stopping protrusion, one end of the rotation-stopping protrusion away from the sliding nut extends into the guide groove and can be slidably fitted with the guide groove along the axial direction of the valve, and the rotation-stopping protrusion and the guide groove constitute the limit structure.

[0016] Compared with existing technologies, this can improve the pre-tightening force of the valve core assembly on the first or second valve port. Even if the valve core assembly is subjected to vibration, it is difficult for a gap to be generated between the valve core assembly and the first valve port under the pre-tightening force of the first pre-tightening structure and / or the second pre-tightening structure. Similarly, it is difficult for a gap to be generated 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. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this application or the conventional technology, the drawings used in the description of the embodiments or the conventional technology will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

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

[0019] Figure 2 for Figure 1 A partial structural schematic diagram of the electronic expansion valve shown.

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

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

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

[0023] Reference numerals: 100, Rotor assembly; 200, Lead screw; 220, First limiting member; 230, Second limiting 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 element; 630, Third elastic element; 660, Third limiting member; 670, Fourth limiting member; 800, Housing; 900, Stator assembly. Detailed Implementation

[0024] In the description of the present application, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate the orientation or positional relationship shown in the drawings, which are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation of the present application.

[0025] In addition, the terms "first", "second" are only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined with "first", "second" can explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "a plurality of" is at least two, such as two, three, etc., unless otherwise explicitly specified and limited.

[0026] In the present application, unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connecting", "fixing" and the like should be understood broadly, for example, it can be fixed connection, or detachable connection, or integral; it can be mechanical connection, or electrical connection; it can be directly connected, or indirectly connected through intermediate medium, it can be the internal communication of two elements or the interaction relationship between two elements, unless otherwise explicitly limited. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0027] In the present application, unless otherwise explicitly specified and limited, the first feature is "on" or "under" the second feature, which can be direct contact between the first and second features, or indirect contact between the first and second features through intermediate medium. Moreover, the first feature "above", "above" and "above" the second feature can be directly above or obliquely above the first feature, or only indicate that the horizontal height of the first feature is higher than that of the second feature. The first feature "below", "below" and "below" the second feature can be directly below or obliquely below the first feature, or only indicate that the horizontal height of the first feature is less than that of the second feature.

[0028] It is to be understood that when an element such as a layer, region or substrate is referred to as being "on" or "connected to" another element, it can be directly on or connected to the other element or intervening elements can be present. In contrast, when an element is referred to as being "directly on" or "directly connected to" another element, there are no intervening elements present. It will be understood that, although the terms "first", "second", etc. can be used herein to describe various elements, these elements should not be limited by these terms since such elements are commonly called by different names in different contexts. For example, a first element could be termed a second element, and, similarly, a second element could be termed a first element without departing from the intended meaning or scope. The terms "and / or" and / or "at least one of" include any and all combinations of one or more of the associated listed items. It will be understood that when an element is referred to as being "connected to" another element, it can be directly connected to the other element or intervening elements can be present. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0029] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description of the application herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0030] Reference will now be made to the drawings, wherein Figures 1-5 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 is capable of moving along the axial direction of the screw rod 200 relative to the valve seat assembly 400. 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. The rotor assembly 100 is capable of driving 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 further 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 is capable of exerting a force on 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 is capable of exerting a force on 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 improved, and the sealing performance of the electronic expansion valve can be improved.

[0033] Further, in an embodiment, the valve core assembly 300 comprises a first valve needle 321 and a second valve needle 322, the lead screw 200 is capable of driving the first valve needle 321 to move the second valve needle 322 along the axis of the second valve needle 322 towards the rotor assembly 100. Specifically, the electronic expansion valve further comprises a stop seat 510 connected with the valve seat assembly 400, the stop seat 510 is sleeved on the lead screw 200. The valve core assembly 300 further comprises a sliding nut 310, the first valve needle 321 and the second valve needle 322, the end of the lead screw 200 away from the rotor assembly 100 is threadedly connected with the sliding nut 310, and the sliding nut 310 and the stop seat 510 are slidably connected along the axis of the lead screw 200, the rotor assembly 100 is connected to the end of the lead screw 200 away from the sliding nut 310, and the lead screw 200 is capable of driving the sliding nut 310 to move the second valve needle 322 along the axis of the second valve needle 322 towards the rotor assembly 100 through the first valve needle 321, so as to close the first valve port 440, and the lead screw 200 is capable of driving the sliding nut 310 to move the second valve needle 322 along the axis of the second valve needle 322 away from the rotor assembly 100 through the first valve needle 321, so as to close the second valve port 450.

[0034] The sliding nut 310 and the stop seat 510 or the valve seat assembly 400 are matched by the limiting structure, so that the lead screw 200 is capable of driving the sliding nut 310 to move the valve core assembly 300 along the axis of the lead screw 200, so as to open or close the first valve port 440 and the second valve port 450, and the limiting structure is capable of preventing the sliding nut 310 from rotating around the axis of the lead screw 200.

[0035] It should be noted that the working principle of the sliding nut 310 is as follows. Specifically, the sliding nut 310 is provided with a rotation-stopping protrusion 311 extending along the radial direction of the sliding nut 310, the stop seat 510 or the valve seat assembly 400 is provided with a guide groove 515 extending along the axial direction of the stop seat 510 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 is slidably matched 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 are slidably matched along the axial direction of the stop seat 510. Moreover, the rotation-stopping protrusion 311 and the guide groove 515 constitute the limiting structure.

[0036] Further, in an embodiment, the first pre-tightening structure is a first elastic member 610, one end of the first elastic member 610 is connected with the lead screw 200, and the other end is connected with the stop seat 510, and the connection herein includes abutment. The first elastic member 610 is a compression elastic member, so that the lead screw 200 and the stop seat 510 are movably matched along the axis of the lead screw 200 through the first elastic member 610.

[0037] Further, in an 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 of the third elastic member 630 is connected to the second valve needle 322, where the connection includes abutting. 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 arranged between the first interface 431 and the second interface 432, and the second valve port 450 is arranged on the side of the second interface 432 away from the first interface 431.

[0039] In this way, it is defined that when the rotor assembly 100 rotates along the preset direction, and the screw rod 200 drives the valve core assembly 300 to move towards the first preset position close to the rotor assembly 100, the valve core assembly 300 can close the first valve port 440, and the second interface 432 communicates 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, and since 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, at this time, the screw rod 200 and the rotor assembly 100 drive the first valve needle 321 to move away from the second valve needle 322 and towards the direction away from the first valve port 440, and in the process of moving the screw rod 200, the first valve needle 321 is driven to press the third elastic member 630, so that the third elastic member 630 generates an elastic force on the second valve needle 322, which can drive the second valve needle 322 to further press the first valve port 440, so that the second valve needle 322 generates a pre-tightening force on the first valve port 440, and improves 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 along the direction opposite to the preset direction, and the screw rod 200 drives the valve core assembly 300 to move to the second preset position away from the rotor assembly 100, the valve core assembly 300 can close the second valve port 450, and the first interface 431 communicates 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 continue to move, and since the screw rod 200 and the valve seat assembly 400 can be movably matched with the screw rod 200 in the axial direction through the first elastic member 610, the screw rod 200 and the rotor assembly 100 move towards the direction away from the second valve port 450, and the first elastic member 610 generates an elastic force on the screw rod 200 during the movement of the screw rod 200, which can drive the screw rod 200 to further press the second valve port 450 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 comprises a housing 800 and a stator assembly 900, the housing 800 is arranged outside the rotor assembly 100, part of the screw rod 200 and part of the valve core assembly 300 and is welded to the valve seat. The stator assembly 900 is arranged outside the housing 800, and the stator assembly 900 can drive the rotor assembly 100 to rotate.

[0044] Further, in an embodiment, the first elastic member 610 is a compression spring, and the first elastic member 610 is arranged outside the screw rod 200.

[0045] In this way, the machining 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 an embodiment, the third elastic member 630 is a compression spring, and the third elastic member 630 is arranged outside part of the first valve needle 321, the second valve needle 322 is arranged outside part of the first valve needle 321, the third elastic member 630 is located in 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 machining difficulty of the third elastic member 630 is significantly reduced, and the assembly difficulty of the third elastic member 630 is reduced.

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

[0049] Further, in an 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 wear degree of the screw rod 200 and the stop seat 510 can be significantly reduced.

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

[0052] Since the screw rod 200 can drive the bearing inner ring of the first limiting member 220 to rotate synchronously, and the second limiting member 230 is a first rod body step 240 formed on the outer wall of the screw rod 200 and fixedly connected to the outer wall of the screw rod 200, the two ends of the first elastic member 610 can rotate synchronously with the screw rod 200. In this way, the wear between the first elastic member 610, the screw rod 200 and the valve seat assembly 400 is greatly reduced, and the service life of the electronic expansion valve is improved.

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

[0054] Since the stop seat 510 can limit the bearing outer ring of the first limiting member 220 from rotating circumferentially, and the second limiting 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 with the stop seat 510. In this way, the wear between the first elastic member 610, the screw rod 200 and the stop seat 510 is also greatly reduced, and the service life of the electronic expansion valve is improved.

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

[0056] In an 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 fixedly connected to the outer wall of the first valve needle 321.

[0057] Further, in an embodiment, the first needle body step 3212 is guided and matched along the axial direction of the second valve needle 322 at one end away from the outer wall of the first valve needle 321 and the inner wall of the second valve needle 322.

[0058] In an embodiment, the electronic expansion valve further comprises a third elastic sealing ring 480, the third elastic sealing ring 480 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 is in sealing and movable cooperation with the valve seat assembly 400 through the third elastic sealing ring 480.

[0059] In this way, the guiding and cooperation of the second valve needle 322 and the valve seat assembly 400 can be realized 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 comprises a stator assembly 900, the stator assembly 900 is sleeved on the outer side of the shell 800, and the stator assembly 900 can drive the rotor assembly 100 to rotate.

[0061] The technical features of the above-mentioned embodiments can be combined in any way. In order to make the description simple, not all possible combinations of the technical features in the above-mentioned embodiments are described, however, as long as the combinations of the technical features do not exist contradictory, they should be considered as the scope of the description.

[0062] The above-mentioned embodiments only express several implementation manners of the present application, the description is more specific and detailed, but it should not be understood as a limitation on the patent scope of the application. It should be pointed out that for ordinary skilled in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are all within the protection scope of the present application. Therefore, the patent protection scope of the present application should be subject to the appended claims.

Claims

1. An electronic expansion valve characterized by, The electronic expansion valve 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) is capable of moving along the axial direction of the screw rod (200) relative to the valve seat assembly (400), one end of the screw rod (200) is fixedly connected to the rotor assembly (100), the other end is connected to the valve core assembly (300), and the rotor assembly (100) is capable of driving 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), the electronic expansion valve further comprises a first pre-tightening structure and 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 is capable of exerting an action force on 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 is capable of exerting an action force on the valve core assembly (300) to press the second valve port (450); The electronic expansion valve further comprises a stop seat (510) connected to the valve seat assembly (400), 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), the other end is connected to the stop seat (510), the first elastic member (610) is a compression elastic member, so that the screw rod (200) and the stop seat (510) are capable of moving along the axial direction of the screw rod (200) through the first elastic member (610); 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); The electronic expansion valve further comprises a first limiting member (220) and a second limiting member (230), one of the first limiting member (220) and the second limiting member (230) is fixedly connected to the stop seat (510), the other is fixedly connected to the screw rod (200), one end of the first elastic member (610) is connected to the first limiting member (220), the other end is connected to the second limiting member (230); One of the first limiting member (220) and the second limiting member (230) is a bearing member, 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).

2. The electronic expansion valve according to claim 1, characterized in that The valve core assembly (300) comprises a first valve needle (321) and a second valve needle (322), the screw rod (200) can drive the first valve needle (321) to move the second valve needle (322) along the axis thereof towards the rotor assembly (100) to close the first valve port (440), and the screw rod (200) can drive the first valve needle (321) to move the second valve needle (322) along the axis thereof away from the rotor assembly (100) to close the second valve port (450).

3. 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), 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).

4. The electronic expansion valve according to claim 3, 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 part of the first valve needle (321), the second valve needle (322) is sleeved on the outer side of part 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).

5. The electronic expansion valve according to claim 3, wherein Further comprising a third limiting member (660) and a fourth limiting member (670), one of the third limiting member (660) and the fourth limiting member (670) is fixedly connected to the first valve needle (321), and the other is fixedly connected to the second valve needle (322), one end of the third elastic member (630) is connected to the third limiting member (660), and the other end is connected to the fourth limiting member (670).

6. The electronic expansion valve according to claim 2, wherein Further comprising a third elastic sealing ring (480), the third elastic sealing ring (480) 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) is movably matched with the valve seat assembly (400) through the third elastic sealing ring (480).

7. The electronic expansion valve according to claim 1, wherein The stop seat (510) is sleeved outside the screw rod (200), the valve core assembly (300) further comprises a sliding nut (310), one end of the screw rod (200) away from the rotor assembly (100) is in threaded cooperation with the sliding nut (310), and the sliding nut (310) and the stop seat (510) or the valve seat assembly (400) are matched through 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), so as 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).

8. The electronic expansion valve according to claim 7, characterized in that The sliding nut (310) is provided with a rotation-stopping protrusion (311) extending along the radial direction thereof, the stop seat (510) or the valve seat assembly (400) is provided with a guide groove (515) extending along the axial direction of the valve corresponding to the rotation-stopping protrusion (311), one end of the rotation-stopping protrusion (311) away from the sliding nut (310) extends into the guide groove (515) and can slide along the axial direction of the valve with the guide groove (515), and the rotation-stopping protrusion (311) and the guide groove (515) constitute the limiting structure.

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