Electronic expansion valve

Abstract

This invention discloses an electronic expansion valve, comprising a valve seat component with a valve port, a lead screw component, and a valve needle component. The lead screw component includes a lead screw shaft and a top shaft. The valve needle component includes a valve stem and a valve needle. The valve stem is axially slidable and confined within the shaft hole of the lead screw shaft. The top shaft and the valve stem are axially opposite to each other. The valve valve also includes first and second elastic components. The two ends of the first spring component abut against the first ends of the top shaft and the valve stem, respectively. The valve needle is movably connected to the valve stem, and the valve stem and valve needle can move relative to each other along the axial direction of the valve seat component. The two ends of the second elastic component abut against the valve needle and the valve stem, respectively. When the top shaft is not in contact with the valve stem, the elastic force of the first elastic component is less than the elastic force of the second elastic component, and the valve stem abuts against the valve needle. When the top shaft is in contact with the valve stem, the elastic force of the first elastic component is less than or equal to the elastic force of the second elastic component, and the abutting portion of the valve stem and valve needle separates. This electronic expansion valve can reduce wear between the valve port and the valve needle component.

Description

Technical Field

[0001] This invention relates to the field of valve technology, and in particular to an electronic expansion valve. Background Technology

[0002] Electronic expansion valves are mostly used in refrigeration systems to regulate the flow of refrigerant.

[0003] The working principle of an electronic expansion valve is that the control element generates a rotating magnetic field through a pulse control coil, controls the rotor to rotate, and drives the lead screw fixed to the rotor to rotate. Under the threaded action of the lead screw and the relatively fixed nut assembly, the lead screw drives the valve needle component to move up and down to approach or move away from the valve port through the downward pressure spring, thereby adjusting the opening of the valve port to control the refrigerant flow.

[0004] The downward pressure spring must always ensure that the valve needle presses against the valve port. The spring force is relatively large. At the moment the valve needle component contacts the valve port, the valve port is subjected to a large impact from the valve needle component, which will generate a lot of noise. Furthermore, after a long period of use, the wear generated at the contact position between the valve port and the valve needle component will affect the control accuracy of the electronic expansion valve. Summary of the Invention

[0005] The purpose of this invention is to provide an electronic expansion valve whose structural design can reduce the impact force on the valve port at the moment the valve needle component contacts the valve port, thereby reducing noise and wear on the valve port and valve needle component.

[0006] To solve the above-mentioned technical problems, the present invention provides an electronic expansion valve, including a valve seat component, a lead screw component, and a valve needle component. The valve seat component has a valve port, and the lead screw component includes a lead screw shaft and a top shaft.

[0007] The valve needle component includes a valve stem and a valve needle. The valve stem is axially slidable and limited within the shaft hole of the lead screw shaft. The top shaft and the valve stem are arranged opposite to each other in the axial direction of the valve stem.

[0008] The electronic expansion valve further includes a first elastic component and a second elastic component, one end of the first spring component abuts against the top shaft, and the other end of the first spring component abuts against the first end of the valve stem;

[0009] The valve needle is movably connected to the second end of the valve stem, and the valve stem and the valve needle can move relative to each other along the axial direction of the valve seat component. One end of the second elastic component abuts against the valve needle, and the other end of the second elastic component abuts against the valve stem.

[0010] When the top shaft is not in contact with the valve stem, the elastic force of the first elastic component is less than the elastic force of the second elastic component, and the valve stem abuts against the valve needle.

[0011] When the top shaft contacts the valve stem, the elastic force of the first elastic component is less than or equal to the elastic force of the second elastic component, and the valve stem separates from the valve needle at the point of contact.

[0012] In this way, when the valve needle just comes into contact with the valve port and the top shaft is not in contact with the valve stem, the force between the valve needle and the valve port comes from the first elastic component with a smaller elastic force. When the top shaft comes into contact with the valve stem, the second elastic component with a larger elastic force makes the valve needle press against the valve port. However, at this time, there is no relative displacement between the valve needle and the valve port, which results in less noise and wear.

[0013] As described above, in the electronic expansion valve, during the period from the valve needle contacting the valve port to the top shaft abutting against the first end, the elastic force of the first elastic member is less than the elastic force of the second elastic member. Under the action of the second elastic member, the valve needle abuts against the valve stem.

[0014] As described above, in the electronic expansion valve, the lead screw shaft has a limiting step, and the valve needle component includes a valve stem sleeve, which is fixedly fitted onto the valve stem and can press against the limiting step.

[0015] As described above, in the electronic expansion valve, the top shaft has a radially outwardly extending radially, and the top shaft also has a limiting shaft section extending toward the valve stem. The first end of the valve stem further includes a stepped surface facing the top shaft. The two ends of the first elastic member abut against the radially extending ...

[0016] As described above, the electronic expansion valve further includes a sleeve, a second elastic component located inside the sleeve, the sleeve being fixedly connected to the valve needle, the sleeve having a first suspension portion, the valve stem having a first support portion, the first suspension portion being closer to the top shaft relative to the first support portion, one end of the second elastic component abutting against the first support portion, and the first suspension portion being able to abut against the first support portion.

[0017] As described above, in the electronic expansion valve, the second end of the valve stem is provided with an annular boss extending radially outward, and the first support portion includes the annular boss; the sleeve includes a cylindrical peripheral wall, the top end of which extends radially inward to form an annular plate portion, and the first suspension portion includes the annular plate portion.

[0018] As described above, the electronic expansion valve further includes a limiting rod segment extending from the annular boss to the valve needle. The cylindrical peripheral wall is fixed to the valve needle. The valve needle includes a limiting protrusion extending towards the valve stem. The two ends of the second elastic member are respectively sleeved on the limiting rod segment and the limiting protrusion.

[0019] As described above, the electronic expansion valve further includes a sleeve, a second elastic component located inside the sleeve, the sleeve being fixedly connected to the second end of the valve stem, the sleeve having a second support portion, the valve needle having a second suspension portion, the second support portion being away from the top shaft relative to the second suspension portion, one end of the second elastic component abutting against the second suspension portion, and the second support portion being able to abut against the second suspension portion.

[0020] As described above, in the electronic expansion valve, the valve needle includes an annular protrusion extending radially outward, and the second suspension portion includes the annular protrusion; the sleeve includes a top wall and a peripheral wall, the top wall is fixedly connected to the valve stem, the bottom end of the peripheral wall extends radially inward to form an annular plate portion, and the second support portion includes the annular plate portion.

[0021] As described above, in the electronic expansion valve, the valve needle includes a limiting protrusion that extends from the annular protrusion toward the valve stem. The valve stem has a limiting rod segment that extends into the cylindrical peripheral wall. The two ends of the second elastic member are respectively sleeved on the limiting rod segment and the limiting protrusion. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the electronic expansion valve in the open state in one embodiment of the present invention;

[0023] Figure 2 This is a schematic diagram of the structure of an electronic expansion valve in an embodiment of the present invention, in which the valve needle and valve port are in a state of just contact.

[0024] Figure 3 This is a schematic diagram of the structure of the electronic expansion valve in an embodiment of the present invention, in which the top shaft and valve stem are in a state of just contact.

[0025] Figure 4 This is a schematic diagram of the electronic expansion valve in a fully closed state in one embodiment of the present invention;

[0026] Figure 5 for Figure 3 A magnified view of part I in the middle;

[0027] Figure 6 for Figure 4 A magnified view of a section II;

[0028] Figure 7 This is a schematic diagram of the connection structure of the valve needle, sleeve and valve stem of another embodiment of an electronic expansion valve.

[0029] Explanation of reference numerals in the attached figures:

[0030] Valve seat assembly 10, valve seat 11, valve port 111, valve port portion 112, first connecting pipe 12, second connecting pipe 13, transition piece 14;

[0031] Nut component 20;

[0032] Lead screw assembly 30, lead screw shaft 31, limiting step 311, top shaft 32, radial protrusion 321, limiting shaft section 322, bearing 33, connecting piece 34;

[0033] Valve needle component 40, valve needle 41A, limiting protrusion 411, limiting stepped surface 412A, valve stem 42, annular boss 421A, first support part 4211A, limiting rod section 422, protruding rod section 423, stepped surface 424, valve stem sleeve 43, sleeve 44A, cylinder peripheral wall 441A, annular plate part 442A, first suspension part 4421A;

[0034] Valve needle 41B, annular protrusion 411B, second suspension part 4111B, sleeve 44B, cylinder peripheral wall 441B, cylinder top wall 442B, annular plate part 443B, second support part 4431B.

[0035] Rotor component 50, first elastic component 60, second elastic component 70, housing 80. Detailed Implementation

[0036] To enable those skilled in the art to better understand the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0037] Please refer to Figures 1 to 6 , Figure 1 This is a schematic diagram of the electronic expansion valve in the open state in one embodiment of the present invention; Figure 2 This is a schematic diagram of the structure of an electronic expansion valve in an embodiment of the present invention, in which the valve needle and valve port are in a state of just contact. Figure 3 This is a schematic diagram of the structure of the electronic expansion valve in an embodiment of the present invention, in which the top shaft and valve stem are in a state of just contact. Figure 4 This is a schematic diagram of the electronic expansion valve in a fully closed state in one embodiment of the present invention; Figure 5 for Figure 3 A magnified view of part I in the middle; Figure 6 for Figure 4 A magnified view of part II in the middle section.

[0038] In this embodiment, the electronic expansion valve includes a valve seat component 10, a nut component 20, a lead screw component 30, a valve needle component 40, and a rotor component 50.

[0039] The valve seat component 10 includes a valve seat 11, which has a valve port portion 112 and a valve port 111. In the figure, the valve seat 11 is an integral structure. In other embodiments, the valve seat 11 may also be a split structure, including a main body portion and a valve port portion. The valve seat 11 is also fixedly connected to a first connecting pipe 12 and a second connecting pipe 13. By adjusting the opening degree of the valve port 111, the refrigerant flow rate between the first connecting pipe 12 and the second connecting pipe 13 can be controlled.

[0040] Typically, a transition piece 14 is fitted over the valve seat 11, and a housing 80 is fixed to the transition piece 14. The housing 80 has space inside to accommodate the main structural components of the electronic expansion valve.

[0041] The term "axial direction" in this article refers to the axial direction of the valve seat 11. Along the axial direction of the valve seat 10, the end of the nut component 20, the lead screw component 30, and the valve needle component 40 closest to the valve port 111 is defined as the lower end, and the end furthest from the valve port 111 is defined as the upper end.

[0042] The nut component 20 is fixed to the valve seat 11. This fixing can be direct or indirect. In the figure, the nut component 20 is fixed to the valve seat 11 through a connecting piece. Specifically, the lower end of the nut component 20 is fixedly inserted into the valve seat 11. The nut component 20 has a through hole with an internal thread section.

[0043] The lead screw assembly 30 includes a lead screw shaft 31 and a top shaft 32. The lead screw shaft 31 has a through shaft hole, and a bearing 33 is fixed at the upper end of the shaft hole. The top shaft 32 is inserted into the bearing 33, and the top shaft 32 is axially fixed relative to the lead screw shaft 31. The lead screw shaft 31 is fixed relative to the rotor assembly 50 through a connecting piece 34, so that when the rotor assembly 50 rotates, it can drive the lead screw shaft 31 to rotate together. The lead screw shaft 31 has an external thread section that is threaded to the internal thread section of the nut assembly 20. Thus, when the lead screw shaft 31 rotates with the rotor assembly 50, it can also move along the axial direction of the valve seat assembly 10 under the action of the threaded connection with the nut assembly 20, so as to drive the valve needle assembly 40 to move closer to or away from the valve port 111.

[0044] The valve needle component 40 includes a valve needle 41A and a valve stem 42. The valve stem 42 is axially slidable and confined within the shaft hole of the lead screw shaft 31. The valve stem 42 and the top shaft 32 are arranged opposite each other in the axial direction of the valve stem 42. A first elastic component 60 is provided between the top shaft 32 and the first end of the valve stem 42. One end of the first elastic component 60 abuts against the top shaft 32, and the other end abuts against the valve stem 42.

[0045] The axial limiting method between the valve stem 42 and the lead screw shaft 31 can adopt the following structure: the lead screw shaft 31 has a limiting step 311, and the valve needle component 40 also includes a valve stem sleeve 43, which is fixedly sleeved on the valve stem 42, specifically on the outer circumference of the valve stem 42. In this way, the valve stem sleeve 43 can press against the limiting step 311 of the lead screw shaft 31. Specifically, under the action of the first elastic component 60, the valve stem sleeve 43 can be pressed against the limiting step 311 of the lead screw shaft 31, thereby limiting the axial position between the valve stem 42 and the lead screw shaft 31.

[0046] The valve needle 41A is movably connected to the second end of the valve stem 42 so that the valve stem 42 can move relative to the valve needle 41A along the axial direction of the valve seat component 10. A second elastic component 70 is provided between the valve needle 41A and the valve stem 42. One end of the second elastic component 70 abuts against the valve stem 42, and the other end abuts against the valve needle 41A.

[0047] During the period from when the valve needle 41A begins to close the valve to when the valve needle 41A contacts the valve port 112, the valve stem 42 and the lead screw shaft 31 are fixed relative to each other in the axial direction. The top shaft 32 and the first end of the valve stem 42 do not abut against each other. The elastic force of the first elastic member 60 is less than the elastic force of the second elastic member 70. The valve stem 42 abuts against the valve needle 41A.

[0048] From the moment the valve needle 41A contacts the valve port 112 until the top shaft 32 abuts against the first end of the valve stem 42, the lead screw 31 moves relative to the valve stem 42 towards the valve port 111 along the axial direction of the valve seat component 10. The elastic force of the first elastic member 60 is less than the elastic force of the second elastic member 70, and the valve stem 42 abuts against the valve needle 41A. After the top shaft 32 contacts the valve stem 42, the elastic force of the first elastic member 60 is less than or equal to the elastic force of the second elastic member 70, and the portion of the valve stem 42 that abuts against the valve needle 41A separates. The valve stem 42 then moves relative to the valve needle 41A towards the valve port 111 along the axial direction of the valve seat component 10.

[0049] With this configuration, when the valve needle 41A just contacts the valve port 112 and the push pin 32 is not in contact with the valve stem 42, the force acting between the valve needle 41A and the valve port 112 comes from the first elastic component 60 with a smaller elastic force. This can reduce the impact force of the valve needle 41A on the valve port 112, reduce the wear between the valve needle 41A and the valve port 112, extend the service life of the valve needle 41A and the valve port 112, and also reduce noise. In addition, after the valve needle 41A contacts the valve port 112 and the push pin 32 contacts the valve stem 42, the second elastic component 70 with a larger elastic force makes the valve needle 41A press against the valve port 112. However, at this time, no relative displacement is generated between the valve needle 41A and the valve port 112, thus resulting in less noise and wear.

[0050] The valve needle component 40 also includes a sleeve 44A, which is fixedly connected to the valve needle 41A. The sleeve 44A is provided with a first suspension part 4421A, and the valve stem 42 is provided with a first support part 4211A. The first suspension part 4421A is close to the top shaft 32 relative to the first support part 4211A. One end of the second elastic component 70 abuts against the first support part 4211A, and the first suspension part 4421A can abut against the first support part 4211A.

[0051] Specifically, the second end of the valve stem 42 is provided with an annular boss 421A extending radially outward, the first support portion 4211A includes the annular boss 421A; the sleeve 44A includes a cylindrical peripheral wall 441A, the top end of the cylindrical peripheral wall 441A extends radially inward to form an annular plate portion 442A, the first suspension portion 4421A includes the annular plate portion 442A, specifically, the bottom end portion of the annular plate portion 442A overlaps the top end portion of the annular boss 421A, and one end of the second elastic member 70 abuts against the bottom end portion of the annular boss 421A.

[0052] The second elastic component 70 is located inside the sleeve 441A, specifically inside the cylindrical circumferential wall 441A of the sleeve 44A, to restrict its position and prevent bending. Specifically, the valve stem 42 also includes a limiting rod segment 422 located below the annular boss 421A, that is, the limiting rod segment 422 extends from the annular boss 421A towards the valve needle 41A. The cylindrical circumferential wall 441A of the sleeve 44A is fixedly connected to the valve needle 41A, and the valve needle 41A includes a limiting protrusion 411 extending towards the valve stem 42. The second elastic component 70 can specifically be a spring, with its two ends respectively sleeved on the limiting rod end 422 and the limiting protrusion 411. Figure 5 As shown.

[0053] In order to facilitate positioning and fixing, the valve needle 41A can also be provided with an upward limiting step surface 412A, and the lower end surface of the sleeve 44A's peripheral wall 441A abuts against the limiting step surface 412A.

[0054] like Figure 1 As shown, the electronic expansion valve is in the open state. At this time, the valve needle 41A is not in contact with the valve port 112 of the valve seat 11, and the valve port 111 of the valve port 112 is in the fully open state. The lower end face of the valve stem sleeve 43 abuts against the limiting step 311 of the lead screw shaft 31, so that the valve needle component 40 and the lead screw shaft 31 have no relative displacement in the axial direction. The first support part 4211A of the valve stem 42 supports the first suspension part 4421A of the sleeve 44A, and the sleeve 44A cannot move relative to the valve stem 42.

[0055] When the valve is closed, the rotor assembly 50 drives the lead screw assembly 30 to rotate. The lead screw assembly 30, under the action of its threaded engagement with the nut assembly 20, moves downwards, that is, towards the valve port 112, and drives the valve needle assembly 40 downwards together. Figure 2 As shown, at this state, the valve needle 41A is just in contact with the valve port 112 of the valve seat 11. The states between the components of the valve needle assembly 40, and the relative positions between the valve needle assembly 40 and the lead screw assembly 30, are still... Figure 1 The same as shown.

[0056] As the lead screw assembly 30 continues to rotate and move downward, the valve needle 41A cannot continue to move downward because it is in contact with the valve port 112. At this time, the lead screw shaft 31 moves downward relative to the valve stem 42, and the limiting step 311 of the lead screw shaft 31 disengages from the valve stem sleeve 43. During the downward movement of the lead screw shaft 31, it drives the top shaft 32 to move downward together until the lead screw shaft 31 drives the top shaft 32 to move downward to the state where the top shaft 32 abuts against the valve stem 42. Figure 3 The status shown is also for reference. Figure 5 At this time, the relative positions of valve needle 41A, sleeve 44A, and valve stem 42 are still as described above. Figure 1 and Figure 2 As shown, the first support portion 4211A of the valve stem 42 abuts against the first suspension portion 4421A of the sleeve 44A.

[0057] Figure 3 As shown, the top shaft 32 moves down to contact the valve stem 42. From this position, as the lead screw assembly 30 continues to rotate and move downward, the top shaft 32 will press the valve stem 42 downward together. At this time, because the valve needle 41A is still in contact with the valve port 112, the valve needle 41A will not move downward. However, during this process, the valve stem 42 moves downward relative to the valve needle 41A, and its first support part 4211A disengages from the first suspension part 4421A of the sleeve 44A, as... Figure 4 and Figure 6 As shown, during the downward movement of the valve stem 42 relative to the valve needle 41A, the second elastic component 70 with greater elasticity causes the valve needle 41A to press against the valve port 112.

[0058] In this embodiment, the top shaft 32 has a radial protrusion 321 extending outward in the radial direction. After the top shaft 32 passes through the bearing 33, the radial protrusion 321 abuts against the lower end face of the bearing 33 to limit the relative position of the top shaft 32 and the bearing 33.

[0059] The first elastic member 60 can also be a spring. The top shaft 32 has a limiting shaft section 322 extending towards the valve stem below the radial protrusion 321. The upper end of the valve stem 42 extends through the upper end of the valve stem sleeve 43 to form an extension shaft section 423. A stepped surface 424 facing the top shaft 32 is formed between the extension shaft section 423 and the main body of the valve stem 42. The two ends of the first elastic member 60 abut against the radial protrusion 321 and the stepped surface 424 respectively, and are respectively sleeved on the limiting shaft section 322 and the extension shaft section 423. In this way, the position of the first elastic member 60 can be better restricted.

[0060] Specifically, when the valve stem sleeve 43 abuts against the limiting step 311, the distance between the valve stem 42 and the top shaft 32 is 0.2mm to 1.2mm.

[0061] In the above embodiment, the valve needle 41A of the valve needle component 40 is movably connected to the valve stem 42 via a sleeve 44A fixed thereto. In actual installation, the movable connection between the valve needle and the valve stem can also be in other ways, such as... Figure 7 The proposed scheme Figure 7 This is a schematic diagram illustrating the connection structure of the valve needle, sleeve, and valve stem in another embodiment of an electronic expansion valve. In this case, the other structures of the electronic expansion valve remain consistent with the aforementioned embodiment, the difference being the connection method between the valve needle and valve stem; only this difference will be explained.

[0062] In this embodiment, the valve needle component 40 still includes a sleeve 44B, which is fixedly connected to the valve stem 42. A second support portion 4431B is provided on the sleeve 44B, and a second suspension portion 4111B is provided on the valve needle 41B. The second support portion 4431B is away from the top shaft 32 relative to the second suspension portion 4111B. One end of the second elastic component 70 abuts against the second suspension portion 4111B. The second support portion 4431B can abut against the second suspension portion 4111B. When the valve needle 41B cannot move down after contacting the valve port 112, the second support portion 4431B of the sleeve 44B can disengage from the second suspension portion 4111B and move down relative to the valve needle 41B.

[0063] Specifically, the valve needle 41B includes an annular protrusion 411B extending radially outward, and the second suspension portion 4111B includes the annular protrusion 411B; the sleeve 44B includes a peripheral wall 441B and a top wall 442B, the top wall 442B being fixedly connected to the valve stem 42, and the bottom end of the peripheral wall 441B extending radially inward to form an annular plate portion 443B, the second support portion 4431B including the annular plate portion 443B. It can be understood that the valve needle 41B is essentially connected to the second support portion 4431B of the sleeve 44B via its second suspension portion 4111B; specifically, the bottom end of the annular protrusion 411B connects to the top end of the annular plate portion 443B, and one end of the second elastic member 70 abuts against the top end of the annular protrusion 411B.

[0064] The second elastic member 70 is also located inside the cylindrical peripheral wall 441B of the sleeve 44B to restrict its position and prevent it from bending. Specifically, the valve needle 41B also includes a limiting protrusion 411 located above the annular protrusion 411B, that is, the limiting protrusion 411 extends from the annular protrusion 411B to the valve stem 42; the valve stem 42 has a limiting rod section 422 that extends into the cylindrical peripheral wall 441B. The second elastic member 70 can be a spring, with its two ends respectively sleeved on the limiting protrusion 411 and the limiting rod end 422 for better positioning.

[0065] The electronic expansion valve provided by this invention has been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the embodiments above are merely for the purpose of helping to understand the method and core ideas of this invention. It should be noted that those skilled in the art can make various improvements and modifications to this invention without departing from its principles, and these improvements and modifications also fall within the protection scope of the claims of this invention.

Claims

1. An electronic expansion valve, comprising a valve seat assembly, a lead screw assembly, and a valve needle assembly, wherein the valve seat assembly has a valve port portion, characterized in that, The lead screw assembly includes a lead screw shaft and a top shaft, wherein the top shaft and the lead screw shaft are fixed relative to each other in the axial direction; The valve needle component includes a valve stem and a valve needle. The valve stem is axially slidable and limited within the shaft hole of the lead screw shaft. The top shaft and the valve stem are arranged opposite to each other in the axial direction of the valve stem. The electronic expansion valve further includes a first elastic component and a second elastic component, one end of the first elastic component abutting against the top shaft, and the other end of the first elastic component abutting against the first end of the valve stem; The valve needle is movably connected to the second end of the valve stem, and the valve stem and the valve needle can move relative to each other along the axial direction of the valve seat component. One end of the second elastic component abuts against the valve needle, and the other end of the second elastic component abuts against the valve stem. When the top shaft is not in contact with the valve stem, the elastic force of the first elastic component is less than the elastic force of the second elastic component, and the valve stem abuts against the valve needle. When the top shaft contacts the valve stem, the elastic force of the first elastic component is less than or equal to the elastic force of the second elastic component, and the valve stem separates from the valve needle at the point of contact.

2. The electronic expansion valve according to claim 1, characterized in that, During the period from when the valve needle contacts the valve port to when the top shaft abuts against the first end, the elastic force of the first elastic component is less than the elastic force of the second elastic component. Under the action of the second elastic component, the valve needle abuts against the valve stem.

3. The electronic expansion valve according to claim 1, characterized in that, The lead screw shaft has a limiting step, and the valve needle component includes a valve stem sleeve, which is fixedly fitted onto the valve stem and can press against the limiting step.

4. The electronic expansion valve according to claim 3, characterized in that, The top shaft has a radially outwardly extending radially protrusion, and the top shaft also has a limiting shaft section extending toward the valve stem. The first end of the valve stem also includes a stepped surface facing the top shaft. The two ends of the first elastic member abut against the radial protrusion and the stepped surface, respectively. When the valve stem sleeve abuts against the limiting step, the distance between the valve stem and the top shaft is 0.2mm to 1.2mm.

5. The electronic expansion valve according to claim 1, characterized in that, The valve needle component also includes a sleeve, the second elastic component is located inside the sleeve, the sleeve is fixedly connected to the valve needle, the sleeve is provided with a first suspension part, the valve stem is provided with a first support part, the first suspension part is close to the top shaft relative to the first support part, one end of the second elastic component abuts against the first support part, and the first suspension part can abut against the first support part.

6. The electronic expansion valve according to claim 5, characterized in that, The valve stem has a second end with an annular boss extending radially outward, and the first support portion includes the annular boss; the sleeve includes a cylindrical peripheral wall, the top end of which extends radially inward to form an annular plate portion, and the first suspension portion includes the annular plate portion.

7. The electronic expansion valve according to claim 6, characterized in that, The valve stem further includes a limiting rod segment, which extends from the annular boss to the valve needle. The cylindrical peripheral wall is fixedly connected to the valve needle. The valve needle includes a limiting protrusion extending to the valve stem. The two ends of the second elastic member are respectively sleeved on the limiting rod segment and the limiting protrusion.

8. The electronic expansion valve according to claim 1, characterized in that, The valve needle component further includes a sleeve, the second elastic component is located inside the sleeve, the sleeve is fixedly connected to the second end of the valve stem, the sleeve is provided with a second support portion, the valve needle is provided with a second suspension portion, the second support portion is away from the top shaft relative to the second suspension portion, one end of the second elastic component abuts against the second suspension portion, and the second support portion can abut against the second suspension portion.

9. The electronic expansion valve according to claim 8, characterized in that, The valve needle includes an annular protrusion extending radially outward, and the second suspension portion includes the annular protrusion; the sleeve includes a top wall and a peripheral wall, the top wall is fixedly connected to the valve stem, the bottom end of the peripheral wall extends radially inward to form an annular plate portion, and the second support portion includes the annular plate portion.

10. The electronic expansion valve according to claim 9, characterized in that, The valve needle includes a limiting protrusion that extends from the annular protrusion toward the valve stem. The valve stem has a limiting rod segment that extends into the cylindrical peripheral wall. The two ends of the second elastic member are respectively sleeved on the limiting rod segment and the limiting protrusion.

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