Electronic expansion valve

Abstract

The utility model discloses an electronic expansion valve which comprises a shell, a first valve element and a second valve element. The shell is provided with a first cavity, a second cavity, a first communicating hole and a first valve port. The first valve needle can move in the axial direction of the shell to block the first valve port, a third cavity and a first flow channel are formed in the first valve needle, the first valve needle is provided with a second valve port communicating with the third cavity, and the first valve needle is provided with a second communicating hole communicating with the third cavity and the first cavity; and the second valve needle can move in the axial direction of the shell to block the second valve port, a second flow channel is defined between the inner circumferential wall of the first valve needle and the outer circumferential wall of the second valve needle, the second flow channel is located on the side, close to the second cavity, of the first flow channel, and the second flow channel communicates with the first flow channel and the second cavity. According to the electronic expansion valve, accurate control over the small flow stage of the electronic expansion valve can be achieved, and the performance of the electronic expansion valve is improved.

Description

Technical Field

[0001] This utility model relates to the field of refrigerant control components, and in particular to an electronic expansion valve. Background Technology

[0002] In existing technologies, vehicle heat pumps require increasingly higher efficiency, lower power consumption, and higher precision in refrigerant regulation. However, traditional electronic expansion valves suffer from poor flow control accuracy, large fluctuations, and high leakage, which can no longer meet user needs. Utility Model Content

[0003] This invention aims to solve at least one of the technical problems existing in the prior art. To this end, this invention proposes an electronic expansion valve that enables precise control of the low-flow stage, reduces flow hysteresis during switching, minimizes flow fluctuations, reduces leakage, and improves the performance of the electronic expansion valve.

[0004] The electronic expansion valve according to an embodiment of the present invention includes: a housing having a first cavity, a second cavity, a first communicating hole, and a first valve port; the first cavity and the second cavity being arranged in the axial direction of the housing; the first communicating hole being disposed on the peripheral wall of the housing and communicating with the first cavity; and the first valve port being disposed at one end of the first cavity away from the second cavity; and a first valve needle disposed within the housing and partially extending into the first cavity; the first valve needle being movable along the axial direction of the housing to block the first valve port; the first valve needle having a third cavity and a first flow channel; and a first valve needle having a connection with the third cavity on its axial end face away from the second cavity. The first valve needle has a second connecting hole on its peripheral wall that communicates with the third cavity and the first cavity. The first flow channel communicates with the first valve port and is spaced apart from both the third cavity and the second connecting hole. The second valve needle passes through the first valve needle and a portion of the second valve needle is located in the third cavity. The second valve needle is movable along the axial direction of the housing to block the second valve port. A second flow channel is defined between the inner peripheral wall of the first valve needle and the outer peripheral wall of the second valve needle. The second flow channel is located on the side of the first flow channel closer to the second cavity and communicates with the first flow channel and the second cavity.

[0005] According to an embodiment of the present invention, the electronic expansion valve has a housing with a first cavity, a second cavity, a first connecting hole, and a first valve port. A first valve needle is movable along the axial direction of the housing to block the first valve port. The first valve needle has a third cavity, a second connecting hole, and a second valve port. A second valve needle is movable along the axial direction of the housing to block the second valve port. When the first valve needle blocks the first valve port, the valve can adjust the fit between the second valve needle and the second valve port to achieve precise control of the small flow stage of the electronic expansion valve, reduce flow hysteresis during the switching process, reduce flow fluctuation, reduce leakage, and improve the performance of the electronic expansion valve. Furthermore, the first valve needle has a first flow channel, and a second flow channel is defined between the inner peripheral wall of the first valve needle and the outer peripheral wall of the second valve needle. The second flow channel is located on the side of the first flow channel closer to the second cavity. The second flow channel connects the first flow channel and the second cavity, which can keep the pressure of the second cavity consistent with that of the first valve port. This ensures that the electronic expansion valve is always in a pressure balance state during the movement of the first and second valve needles, avoiding affecting the normal movement of the first and second valve needles along the axial direction of the housing, and ensuring the reliability and stability of the sealing of the first valve needle at the first valve port and the second valve needle at the second valve port.

[0006] In addition, the electronic expansion valve according to this utility model may also have the following additional technical features:

[0007] In some embodiments, the inner peripheral wall of the first valve needle has a guide protrusion that extends along the circumferential direction of the first valve needle and has a first notch that penetrates the guide protrusion along the axial direction of the housing.

[0008] In some embodiments, the first notch is a plurality of notches spaced apart along the circumferential direction of the guide protrusion.

[0009] In some embodiments, the first flow channel includes a first sub-flow channel and a second sub-flow channel, and the first valve needle includes a guide sleeve and a valve core. The guide sleeve and the valve core are arranged and connected along the axial direction of the housing. The valve core is located on the side of the guide sleeve facing the first valve port. The third cavity, the second valve port, and the second communicating hole are all disposed on the valve core. The second flow channel is defined between the inner peripheral wall of the guide sleeve and the outer peripheral wall of the second valve needle. The first sub-flow channel is formed between the valve core and the guide sleeve. The first sub-flow channel communicates with the second flow channel. The second sub-flow channel is disposed on the valve core and penetrates the valve core along the axial direction of the housing. In the circumferential direction of the first valve needle, the second sub-flow channel is spaced apart from the second communicating hole. The second sub-flow channel communicates with the first sub-flow channel and the first valve port.

[0010] In some embodiments, the first sub-channel is an annular shape extending along the circumferential direction of the second valve needle, and the second sub-channels are a plurality of them spaced apart along the circumferential direction of the first valve needle, and the plurality of second sub-channels are all connected to the first sub-channel.

[0011] In some embodiments, the electronic expansion valve further includes: a limiting assembly disposed within the second cavity and extending along the axial direction of the housing, the limiting assembly having an anti-rotation groove, a first limiting member, and a second limiting member, the anti-rotation groove being disposed on the peripheral wall of the limiting assembly and extending along the axial direction of the housing, the first limiting member and the second limiting member being located at opposite ends of the extension direction of the anti-rotation groove; and a stop assembly disposed within the limiting assembly and movable along the axial direction of the housing, the stop assembly having a stop on its outer peripheral wall that corresponds to the anti-rotation groove. A rotating anti-rotation lug is provided, located between the first limiting member and the second limiting member, both of which restrict the movement of the stop assembly along the axial direction of the housing; a drive assembly is provided on the housing and includes a screw, which extends along the axial direction of the housing, with one end of the screw facing the first valve port connected to the second valve needle, the screw passing through the limiting assembly and the stop assembly, the screw being threadedly connected to the limiting assembly and fixedly connected to the stop assembly.

[0012] In some embodiments, the stop assembly includes: a fixed ring disposed within the limiting assembly and fixedly connected to the screw; a stop ring sleeved on the fixed ring, with an anti-rotation lug disposed on the outer peripheral wall of the stop ring; and a stop bearing disposed between the fixed ring and the stop ring.

[0013] In some embodiments, the anti-rotation lugs are a plurality of lugs spaced apart along the circumferential direction of the stop assembly, and the anti-rotation grooves are a plurality of lugs corresponding one-to-one with the plurality of anti-rotation lugs.

[0014] In some embodiments, the limiting component includes: a limiting post extending along the axial direction of the housing, the limiting post having a groove on its peripheral wall extending along the axial direction of the housing, the groove being open on one side along the axial direction of the housing; a nut disposed on the open side of the groove for sealing the opening of the groove to define the anti-rotation groove, the inner wall of the groove facing away from the nut forming the first limiting member, the end face of the nut facing the first limiting member forming the second limiting member, and a screw passing through both the limiting post and the nut and threadedly connected to the nut.

[0015] In some embodiments, a first elastic element is provided between the limiting component and the first valve needle; and / or, a second elastic element is provided between the limiting component and the second valve needle.

[0016] Additional aspects and advantages of this invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0017] The above and / or additional aspects and advantages of this utility model will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0018] Figure 1 This is a perspective view of an electronic expansion valve according to an embodiment of the present utility model;

[0019] Figure 2 This is a front view of the electronic expansion valve according to an embodiment of the present utility model;

[0020] Figure 3 This is a cross-sectional view of an electronic expansion valve according to an embodiment of the present utility model;

[0021] Figure 4 This is a cross-sectional view of an electronic expansion valve according to an embodiment of the present utility model, wherein the coil component is not shown, the first valve needle closes the first valve port, and the second valve needle closes the second valve port;

[0022] Figure 5 This is a cross-sectional view of an electronic expansion valve according to an embodiment of the present utility model, wherein the coil component is not shown, the first valve needle opens the first valve port, and the second valve needle opens the second valve port;

[0023] Figure 6 This is a perspective view of an electronic expansion valve according to an embodiment of the present utility model, wherein the coil component, rotor component, guide component, and part of the housing are not shown;

[0024] Figure 7 This is a perspective view of an electronic expansion valve according to an embodiment of the present utility model, wherein the coil component, rotor component, guide component, part of the housing and limiting post are not shown;

[0025] Figure 8 This is a cross-sectional view of an electronic expansion valve according to an embodiment of the present utility model, wherein the coil component, rotor component, guide component, part of the housing and limiting post are not shown;

[0026] Figure 9 This is a three-dimensional sectional view of the first valve needle, the second valve needle, and the screw of the electronic expansion valve according to an embodiment of the present utility model;

[0027] Figure 10This is a cross-sectional view of the first valve needle, the second valve needle, and the screw of the electronic expansion valve according to an embodiment of the present utility model;

[0028] Figure 11 This is a perspective view of the first valve needle, the second valve needle, and the screw of the electronic expansion valve according to an embodiment of the present utility model.

[0029] Figure 12 This is a perspective view of the guide sleeve of the first valve needle of the electronic expansion valve according to an embodiment of the present utility model;

[0030] Figure 13 This is a perspective view of the second valve needle and screw assembly of the electronic expansion valve according to an embodiment of the present utility model;

[0031] Figure 14 This is a perspective view of the second valve needle of the electronic expansion valve according to an embodiment of the present utility model;

[0032] Figure 15 This is a perspective view of the stop assembly of the electronic expansion valve according to an embodiment of the present utility model;

[0033] Figure 16 This is a cross-sectional view of the stop assembly of the electronic expansion valve according to an embodiment of the present invention.

[0034] Figure label:

[0035] 100. Electronic expansion valve;

[0036] 1. Housing; 11. First cavity; 12. Second cavity; 13. First connecting hole; 14. First valve port; 141. Sealing gasket;

[0037] 2. First valve needle; 21. Guide sleeve; 211. First component; 212. Second component; 22. Valve core; 221. Valve core body; 222. Valve port seat; 223. Third cavity; 224. Second connecting hole; 225. Second valve port; 226. Protrusion; 23. Guide protrusion; 231. First notch; 24. First flow channel; 241. First sub-flow channel; 242. Second sub-flow channel; 25. Second flow channel; 26. Limiting ring; 271. First sealing ring; 272. Second sealing ring; 273. Sealing ring;

[0038] 3. Second valve needle; 31. Fourth cavity; 32. Balance hole; 33. Limiting ring; 331. Second notch; 36. Third elastic element;

[0039] 4. Limiting component; 41. Limiting post; 411. Through hole; 42. Nut; 43. Anti-rotation groove; 44. First limiting member; 45. Second limiting member; 46. First elastic member; 47. Second elastic member;

[0040] 5. Stop assembly; 51. Retaining ring; 52. Stop ring; 521. Anti-rotation lug; 53. Stop bearing;

[0041] 6. Drive assembly; 61. Screw; 62. Coil assembly; 63. Rotor assembly; 64. Guide component. Detailed Implementation

[0042] The embodiments of this utility model are described in detail below. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this utility model, and should not be construed as limiting this utility model.

[0043] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0044] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.

[0045] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a communication connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0046] The electronic expansion valve 100 according to an embodiment of the present invention is described below with reference to the accompanying drawings.

[0047] like Figure 4As shown, the electronic expansion valve 100 according to an embodiment of the present invention includes a housing 1, a first valve needle 2, and a second valve needle 3.

[0048] Specifically, see the attached document. Figure 1 Appendix Figure 2 and attached Figure 3 As shown, the housing 1 can protect the internal structure of the electronic expansion valve 100, which helps to extend the service life of the electronic expansion valve 100. The housing 1 has a first cavity 11, a second cavity 12, a first connecting hole 13, and a first valve port 14. The first cavity 11 and the second cavity 12 are in the axial direction of the housing 1 (see attached figure). Figure 3 Arranged in the direction shown (a), the first connecting hole 13 is provided on the peripheral wall of the housing 1 and communicates with the first cavity 11, and the first valve port 14 is provided at the end of the first cavity 11 away from the second cavity 12. The medium can flow into the first cavity 11 through one of the first connecting hole 13 and the first valve port 14, and flow out through the other of the first connecting hole 13 and the first valve port 14.

[0049] Further, see Appendix Figure 4 and attached Figure 5 As shown, the first valve needle 2 is located inside the housing 1 and partially extends into the first cavity 11. The first valve needle 2 extends along the axial direction of the housing 1 and can move along the axial direction of the housing 1 to block the first valve port 14. When the first valve needle 2 blocks the first valve port 14, the first connecting hole 13 and the first valve port 14 are no longer connected, the medium cannot flow into the first cavity 11 from the first valve port 14, and the medium in the first cavity 11 cannot flow out from the first valve port 14.

[0050] Furthermore, see the attached document. Figure 4 and attached Figure 5 As shown, the first valve needle 2 has a third cavity 223 and a first flow channel 24. On the axial end face of the first valve needle 2 away from the second cavity 12, there is a second valve port 225 communicating with the third cavity 223. The second valve port 225 is coaxially arranged with the first valve port 14. The peripheral wall of the first valve needle 2 has a second connecting hole 224 communicating with the third cavity 223 and the first cavity 11. The first flow channel 24 communicates with the first valve port 14, and the first flow channel 24 communicates with both the third cavity 223 and the second valve port 14. The holes 224 are spaced apart. The medium can enter the first cavity 11 through the first connecting hole 13, flow into the third cavity 223 through the second connecting hole 224, and finally flow out of the electronic expansion valve 100 through the second valve port 225 and the first valve port 14 in sequence. Alternatively, the medium can enter the third cavity 223 through the first valve port 14 and the second valve port 225 in sequence, enter the first cavity 11 through the second connecting hole 224, and finally flow out of the electronic expansion valve 100 through the first connecting hole 13.

[0051] Furthermore, see the attached document. Figure 4As shown, the second valve needle 3 passes through the first valve needle 2, and part of the second valve needle 3 is located in the third cavity 223. The second valve needle 3 can move along the axial direction of the housing 1 to block the second valve port 225. When the second valve needle 3 blocks the second valve port 225, the second connecting hole 224 and the second valve port 225 are no longer connected, the medium cannot flow from the second valve port 225 into the third cavity 223, and the medium in the third cavity 223 cannot flow out from the second valve port 225.

[0052] Understandably, compared to the high-flow-rate single-valve-needle electronic expansion valves in the prior art, this utility model has a second valve port 225 and a second valve needle 3 for blocking the second valve port 225 in the first valve needle 2. When the first valve needle 2 blocks the first valve port 14, the cooperation between the second valve needle 3 and the second valve port 225 can be adjusted to achieve precise control of the low-flow-rate stage of the electronic expansion valve 100, reduce the flow lag during the switching process, reduce the fluctuation range of the flow, reduce the leakage, and improve the performance of the electronic expansion valve 100.

[0053] Further, see Appendix Figure 4 and attached Figure 9 As shown, the first valve needle 2 has a first flow channel 24, which communicates with the first valve port 14. The first flow channel 24 is spaced apart from the third cavity 223 and the second connecting hole 224. A second flow channel 25 is defined between the inner peripheral wall of the first valve needle 2 and the outer peripheral wall of the second valve needle 3. The second flow channel 25 is located on the side of the first flow channel 24 closest to the second cavity 12. The second flow channel 25 connects the first flow channel 24 and the second cavity 12. The medium can enter the first flow channel 24 from the first valve port 14 and flow through the second valve port 14. The first flow channel 24 enters the second flow channel 25 and finally flows into the second cavity 12 through the second flow channel 25, thereby keeping the pressure in the second cavity 12 consistent with that at the first valve port 14. This ensures that the electronic expansion valve 100 is always in a pressure balance state during the movement of the first valve needle 2 and the second valve needle 3, avoiding affecting the normal movement of the first valve needle 2 and the second valve needle 3 along the axial direction of the housing 1, and ensuring the reliability and stability of the first valve needle 2 sealing the first valve port 14 and the second valve needle 3 sealing the second valve port 225.

[0054] It should be noted that, as Figure 8 , Figure 9 and Figure 10 As shown, by separating the first flow channel 24 from the third cavity 223 and the second connecting hole 224, it is possible to prevent the first flow channel 24 from communicating with the second connecting hole 224 or the third cavity 223 within the first valve needle 2. This prevents the medium from entering the second connecting hole 224 or the third cavity 223 through the first flow channel 24 when the first valve needle 2 blocks the first valve port 14 and the second valve needle 3 blocks the second valve port 225, thereby causing the second valve needle 3 to fail in blocking the second valve port 225.

[0055] It should be noted that the reference appendix Figure 8 As shown, a sealing gasket 141 is provided inside the first valve port 14. The sealing gasket 141 extends in an annular shape along the circumferential direction of the housing 1. The first valve needle 2 is adapted to abut against the sealing gasket 141 to block the first valve port 14. Through the cooperation of the sealing gasket 141 and the first valve needle 2, the blocking effect of the first valve needle 2 on the first valve port 14 can be improved, ensuring the reliability of the first valve needle 2 in blocking the first valve port 14, and preventing the inflow or outflow of the medium when the first valve needle 2 blocks the first valve port 14.

[0056] Furthermore, the sealing gasket 141 is a plastic part, which has good elasticity, light weight, good corrosion resistance, good wear resistance, high strength, and low cost. Specifically, PTFE (polytetrafluoroethylene), PPS (polyphenylene sulfide), PEI (polyethyleneimine), or HNBR (hydrogenated nitrile butadiene rubber) are preferred. Alternatively, the sealing gasket 141 can be obtained by adding carbon fiber, glass fiber, carbon powder, etc., to the above materials, which can further improve the structural strength and hardness of the sealing gasket 141.

[0057] According to an embodiment of the present invention, the electronic expansion valve 100 has a first cavity 11, a second cavity 12, a first connecting hole 13, and a first valve port 14 in the housing 1. The first valve needle 2 is movable along the axial direction of the housing 1 to block the first valve port 14. The first valve needle 2 has a third cavity 223, a second connecting hole 224, and a second valve port 225. The second valve needle 3 is movable along the axial direction of the housing 1 to block the second valve port 225. When the first valve needle 2 blocks the first valve port 14, the precise control of the small flow stage of the electronic expansion valve 100 can be achieved by adjusting the cooperation between the second valve needle 3 and the second valve port 225, thereby reducing the flow lag during the switching process, reducing the flow fluctuation amplitude, reducing leakage, and improving the performance of the electronic expansion valve 100. Furthermore, the first valve needle 2 has a first flow channel 24, and the inner peripheral wall of the first valve needle 2 and the outer peripheral wall of the second valve needle 3 define a second flow channel 25. The second flow channel 25 is located on the side of the first flow channel 24 near the second cavity 12. The second flow channel 25 connects the first flow channel 24 and the second cavity 12, which can keep the pressure of the second cavity 12 and the first valve port 14 consistent, ensuring that the electronic expansion valve 100 is always in a pressure balance state during the movement of the first valve needle 2 and the second valve needle 3, avoiding affecting the normal movement of the first valve needle 2 and the second valve needle 3 along the axial direction of the housing 1, and ensuring the reliability and stability of the first valve needle 2 sealing the first valve port 14 and the second valve needle 3 sealing the second valve port 225.

[0058] In some embodiments of this utility model, reference is made to the appendix. Figure 9As shown, the inner peripheral wall of the first valve needle 2 has a guide protrusion 23, which extends along the circumferential direction of the first valve needle 2. The second valve needle 3 passes through the guide protrusion 23 and is clearance-fitted with the guide protrusion 23. This allows the second valve needle 3 to be inserted into the first valve needle 2 for centering, ensuring the coaxiality of the first valve needle 2 and the second valve needle 3, and reducing the probability of the second valve needle 3 wobbling within the first valve needle 2. When the second valve needle 3 moves relative to the first valve needle 2 along the axial direction of the housing 1, the guide protrusion 23 guides the second valve needle 3, ensuring effective sealing of the second valve needle 3 to the second valve port 225, preventing leakage, avoiding flow fluctuations within the electronic expansion valve 100, and ensuring the performance of the electronic expansion valve 100.

[0059] Further, see Appendix Figure 11 and attached Figure 12 As shown, the guide protrusion 23 has a first notch 231, which extends through the guide protrusion 23 along the axial direction of the housing 1. It should be noted that there is a certain gap between the part of the guide protrusion 23 without the first notch 231 and the outer peripheral wall of the second valve needle 3, allowing the medium to pass through. The setting of the first notch 231 can improve the efficiency of the medium flowing to the second cavity 12, ensure that the pressure at the second cavity 12 and the first valve port 14 is consistent, and ensure that the electronic expansion valve 100 is always in a pressure balance state during the movement of the first valve needle 2 and the second valve needle 3, so as to avoid affecting the normal movement of the first valve needle 2 and the second valve needle 3 along the axial direction of the housing 1, and ensure the reliability and stability of the first valve needle 2 blocking the first valve port 14 and the second valve needle 3 blocking the second valve port 225.

[0060] For example, the first gap 231 can be Figure 12 The notch shown has its inner wall spaced apart from the outer peripheral wall of the second valve needle 3 to increase the gap between the inner peripheral wall of the first valve needle 2 and the outer peripheral wall of the second valve needle 3, thereby increasing the cross-sectional area of ​​the second flow channel 25 and improving the efficiency of the medium flowing to the second cavity 12. The first notch 231 can also be a through hole opened on the guide protrusion 23, which passes through the guide protrusion 23 along the axial direction of the housing 1, and is also used to increase the cross-sectional area of ​​the second flow channel 25 and improve the efficiency of the medium flowing to the second cavity 12.

[0061] In a further embodiment of this utility model, reference is made to the appendix. Figure 11As shown, multiple first notches 231 are spaced apart along the circumferential direction of the guide protrusion 23, which can further increase the cross-sectional area of ​​the second flow channel 25, improve the efficiency of the medium flowing to the second cavity 12, ensure that the pressure at the second cavity 12 and the first valve port 14 is consistent, and ensure that the electronic expansion valve 100 is always in a pressure balance state during the movement of the first valve needle 2 and the second valve needle 3, so as to avoid affecting the normal movement of the first valve needle 2 and the second valve needle 3 along the axial direction of the housing 1, and ensure the reliability and stability of the sealing of the first valve needle 2 to the first valve port 14 and the second valve needle 3 to the second valve port 225. For example, there can be two, three, four, five or six first notches 231 spaced apart along the circumferential direction of the guide protrusion 23.

[0062] In some embodiments of this utility model, reference is made to the appendix. Figure 9 As shown, the second valve needle 3 has a fourth cavity 31, which is located at the end of the second valve needle 3 opposite to the second valve port 225. The outer peripheral wall of the second valve needle 3 has a balance hole 32, which connects the fourth cavity 31 and the second flow channel 25. This allows the medium in the second flow channel 25 to flow into the fourth cavity 31, allowing the medium to pass through the interior of the second valve needle 3. This ensures that the pressure inside the second valve needle 3 is consistent with the pressure outside the second valve needle 3, reducing the risk of failure of the electronic expansion valve 100, improving the performance of the electronic expansion valve 100, extending the service life of the electronic expansion valve 100, and allowing residual fluid or contaminants in the fourth cavity 31 to flow out through the balance hole 32, ensuring the normal use of the electronic expansion valve 100.

[0063] Further, see Appendix Figure 8As shown, multiple balance holes 32 are spaced apart along the circumferential direction of the second valve needle 3. These balance holes 32 are all connected to the fourth cavity 31 and the second flow channel 25. This improves the efficiency of the medium flowing from the second flow channel 25 to the fourth cavity 31, ensuring that the pressure inside the second valve needle 3 is consistent with the pressure outside the second valve needle 3. This facilitates the electronic expansion valve 100 in establishing internal balance more quickly, reducing the risk of failure, improving its performance, and extending its service life. Furthermore, it increases the flow path between the second flow channel 25 and the fourth cavity 31, relatively reducing the probability of impurities clogging the balance holes 32. This ensures that the pressure in the fourth cavity 31 is consistent with that at the first valve port 14, guaranteeing that the electronic expansion valve 100 remains in a pressure-balanced state during the movement of the first valve needle 2 and the second valve needle 3. This avoids affecting the normal movement of the first valve needle 2 and the second valve needle 3 along the axial direction of the housing 1, ensuring the reliability and stability of the sealing of the first valve port 14 by the first valve needle 2 and the second valve port 225 by the second valve needle 3. For example, the balance holes 32 can be two, three, four, five or six spaced apart along the circumferential direction of the second valve needle 3, and each balance hole 32 is connected to the fourth cavity 31 and the second flow channel 25.

[0064] In some embodiments of this utility model, reference is made to the appendix. Figure 10 As shown, a limiting ring 26 is provided on the inner peripheral wall of the first valve needle 2. The limiting ring 26 is located at the end of the first valve needle 2 away from the first valve port 14 and extends along the circumferential direction of the first valve needle 2. The second valve needle 3 passes through the limiting ring 26 and is radially spaced from the limiting ring 26. A limiting ring 33 is provided on the outer peripheral wall of the second valve needle 3 and extends along the circumferential direction of the second valve needle 3. It is used to abut against the surface of the limiting ring 26 facing the first valve port 14. When the limiting ring 33 abuts against the surface of the limiting ring 26 facing the first valve port 14, the second valve needle 3 can drive the first valve needle 2 to move together in the direction away from the first valve port 14, thereby opening the first valve port 14. It should be noted that the opening limit of the second valve needle 3 can be adjusted by adjusting the matching distance between the limiting ring 26 and the limiting ring 33, thereby adjusting the flow curve of the electronic expansion valve 100.

[0065] In a further embodiment of this utility model, reference is made to the appendix. Figure 13 and attached Figure 14As shown, the outer peripheral wall of the limiting ring 33 has a second notch 331. The second notch 331 penetrates the limiting ring 33 along the axial direction of the housing 1. It should be noted that there is a certain gap between the part of the limiting ring 33 without the second notch 331 and the inner peripheral wall of the first valve needle 2, which allows the medium to pass through. The setting of the second notch 331 can improve the efficiency of the medium flowing to the second cavity 12, ensure that the pressure of the second cavity 12 and the first valve port 14 are consistent, and ensure that the electronic expansion valve 100 is always in a pressure balance state during the movement of the first valve needle 2 and the second valve needle 3, so as to avoid affecting the normal movement of the first valve needle 2 and the second valve needle 3 along the axial direction of the housing 1, and ensure the reliability and stability of the first valve needle 2 blocking the first valve port 14 and the second valve needle 3 blocking the second valve port 225.

[0066] Furthermore, multiple second notches 331 are spaced apart along the circumferential direction of the limiting ring 33, which can further improve the efficiency of the medium flowing to the second cavity 12, ensure that the pressure at the second cavity 12 and the first valve port 14 is consistent, and ensure that the electronic expansion valve 100 is always in a pressure balance state during the movement of the first valve needle 2 and the second valve needle 3, so as to avoid affecting the normal movement of the first valve needle 2 and the second valve needle 3 along the axial direction of the housing 1, and ensure the reliability and stability of the sealing of the first valve needle 2 to the first valve port 14 and the second valve needle 3 to the second valve port 225. For example, there can be two, three, four, five or six second notches 331 spaced apart along the circumferential direction of the limiting ring 33.

[0067] In some embodiments of this utility model, reference is made to the appendix. Figure 9 As shown, the first flow channel 24 includes a first sub-flow channel 241 and a second sub-flow channel 242. The first valve needle 2 includes a guide sleeve 21 and a valve core 22. The guide sleeve 21 and the valve core 22 are arranged and connected along the axial direction of the housing 1. The valve core 22 is located on the side of the guide sleeve 21 facing the first valve port 14. The third cavity 223, the second valve port 225, and the second connecting hole 224 are all provided on the valve core 22. The inner peripheral wall of the guide sleeve 21 and the outer peripheral wall of the second valve needle 3 define the second flow channel 25. The valve core 22 and the guide sleeve 21 form the first sub-flow channel 241. The first sub-flow channel 241 is connected to the second flow channel 25. The second sub-flow channel 242 is provided on the valve core 22 and passes through the valve core 22 along the axial direction of the housing 1. In the circumferential direction of the first valve needle 2, the second sub-flow channel 242 is spaced apart from the second connecting hole 224. The second sub-flow channel 242 is connected to the first sub-flow channel 241 and the first valve port 14.

[0068] Understandably, the medium can flow from the first valve port 14 into the second sub-channel 242, then into the first sub-channel 241 defined by the guide sleeve 21 and the valve core 22, and then flow from the first sub-channel 241 to the second channel 25, and finally into the second cavity 12 from the second channel 25. This ensures that the pressure in the second cavity 12 is consistent with that at the first valve port 14, ensuring that the electronic expansion valve 100 is always in a pressure balance state during the movement of the first valve needle 2 and the second valve needle 3, avoiding affecting the normal movement of the first valve needle 2 and the second valve needle 3 along the axial direction of the housing 1, and ensuring the reliability and stability of the first valve needle 2 sealing the first valve port 14 and the second valve needle 3 sealing the second valve port 225.

[0069] Further, see Appendix Figure 9 As shown, the guide sleeve 21 includes a first component 211 and a second component 212 arranged and connected along the axial direction of the housing 1. The second component 212 is located on the side of the first component 211 facing the first valve port 14. The valve core 22 is disposed in the second component 212 and spaced apart from the first component 211 to define a first sub-flow channel 241. The medium flowing in from the second sub-flow channel 242 can flow into the first sub-flow channel 241 defined by the first component 211 and the second component 212.

[0070] Furthermore, see the attached document. Figure 8 As shown, along the axial direction of the housing 1, the end of the second component 212 near the first valve port 14 is located on the side of the second connecting hole 224 opposite to the first valve port 14. The second connecting hole 224 directly connects the first cavity 11 and the third cavity 223, which can reduce the manufacturing difficulty of the first valve needle 2 and facilitate the flow of the medium from the first cavity 11 to the third cavity 223 or from the third cavity 223 to the first cavity 11, ensuring the reliability and stability of the electronic expansion valve 100. It can be understood that the medium can enter the first cavity 11 through the first connecting hole 13, flow into the third cavity 223 through the second connecting hole 224, and finally flow out of the electronic expansion valve 100 through the second valve port 225 and the first valve port 14 in sequence. Alternatively, the medium can pass through the first valve port 14 and the second valve port 225 in sequence into the third cavity 223, enter the first cavity 11 through the second connecting hole 224, and finally flow out of the electronic expansion valve 100 through the first connecting hole 13.

[0071] Optionally, the guide sleeve 21 and the valve core 22 are interference-fitted and / or welded together. When the guide sleeve 21 and the valve core 22 are welded together, a relief groove can be provided so that the welding position is located in the relief groove. This ensures that the weld surface formed after the guide sleeve 21 and the valve core 22 are located in the relief groove, thus avoiding the weld surface formed after welding from affecting the assembly of the electronic expansion valve 100.

[0072] Further, see Appendix Figure 8As shown, a first sealing ring 271 is provided between the outer peripheral wall of the guide sleeve 21 and the inner peripheral wall of the housing 1, which can prevent the medium from flowing from the gap between the guide sleeve 21 and the housing 1 to the second cavity 12, prevent medium leakage, prevent flow fluctuations in the electronic expansion valve 100, and ensure the performance of the electronic expansion valve 100.

[0073] Furthermore, see the attached document. Figure 9 As shown, the valve core 22 has a placement groove on the side facing the guide sleeve 21. The second valve needle 3 passes through the placement groove. A second sealing ring 272 and a sealing retainer ring 273 are provided between the outer peripheral wall of the second valve needle 3 and the inner wall of the placement groove. The second sealing ring 272 is used to prevent the medium from flowing from the gap between the second valve needle 3 and the first valve needle 2 to the second cavity 12, to prevent medium leakage, to prevent flow fluctuations in the electronic expansion valve 100, and to ensure the performance of the electronic expansion valve 100. The sealing retainer ring 273 is located on the side of the second sealing ring 272 away from the first valve port 14. It can be used to prevent the second sealing ring 272 from falling out of the placement groove and can also guide the second valve needle 3 to a certain extent.

[0074] In a further embodiment of this utility model, reference is made to the appendix. Figure 9 As shown, the first sub-channel 241 is an annular shape extending along the circumferential direction of the second valve needle 3. The annular first sub-channel 241 can ensure communication with the second sub-channel 242 and can store a small portion of the medium, thus preventing flow interruption between the second sub-channel 242 and the second channel 25.

[0075] Furthermore, multiple second sub-channels 242 are spaced apart along the circumferential direction of the first valve needle 2. All multiple second sub-channels 242 are connected to the first sub-channel 241, which can increase the flow path of the medium from the first valve port 14 to the first sub-channel 241, reduce the probability of impurities clogging the first channel 24, ensure that the pressure at the second cavity 12 and the first valve port 14 is consistent, and ensure that the electronic expansion valve 100 is always in a pressure balance state during the movement of the first valve needle 2 and the second valve needle 3, avoid affecting the normal movement of the first valve needle 2 and the second valve needle 3 along the axial direction of the housing 1, and ensure the reliability and stability of the first valve needle 2 sealing the first valve port 14 and the second valve needle 3 sealing the second valve port 225.

[0076] For example, the second sub-channels 242 can be two, three, four, five or six spaced apart along the circumferential direction of the first valve needle 2. Each second sub-channel 242 extends along the axial direction of the housing 1, with one end connected to the first sub-channel 241 and the other end open.

[0077] In a further embodiment of this utility model, reference is made to the appendix. Figure 9As shown, the valve core 22 includes a valve core body 221 and a valve seat 222. The valve core body 221 is connected to the guide sleeve 21. The third cavity 223, the second connecting hole 224, and the second sub-flow channel 242 are all disposed on the valve core body 221. A first sub-flow channel 241 is formed between the valve core body 221 and the guide sleeve 21. At least a portion of the valve seat 222 is disposed within the valve core body 221, and the valve seat 222 is press-fitted with the valve core body 221. The valve seat 222 defines a second valve port 225. The valve seat 222 has a protrusion 226 located opposite to the second cavity of the valve seat 222. At one end of body 12, the side face of protrusion 226 facing the second cavity 12 abuts against the side face of valve core body 221 facing the first valve port 14. In the direction from the first cavity 11 to the second cavity 12, the cross-sectional area of ​​protrusion 226 gradually increases. Protrusion 226 can guide the medium flowing from the first valve port 14 into the first cavity 11, which is beneficial to the flow of medium. It can reduce the eddy current formed by the medium hitting the first valve needle 2, reduce the flow resistance of electronic expansion valve 100, thereby reducing the noise of electronic expansion valve 100 and improving the product performance of electronic expansion valve 100.

[0078] In some embodiments of this utility model, reference is made to the appendix. Figure 4 and attached Figure 5 As shown, the electronic expansion valve 100 also includes a limiting component 4, a stop component 5, and a drive component 6. The limiting component 4 is disposed within the second cavity 12 and extends along the axial direction of the housing 1. The limiting component 4 has an anti-rotation groove 43, a first limiting member 44, and a second limiting member 45. The anti-rotation groove 43 is disposed on the peripheral wall of the limiting component 4 and extends along the axial direction of the housing 1. The first limiting member 44 and the second limiting member 45 are respectively located in the extending direction of the anti-rotation groove 43 (see attached diagram). Figure 6 At both ends of direction a shown, the stop assembly 5 is located inside the limiting assembly 4 and can move along the axial direction of the housing 1. The outer peripheral wall of the stop assembly 5 has an anti-rotation lug 521 that cooperates with the anti-rotation groove 43. The anti-rotation lug 521 is located between the first limiting member 44 and the second limiting member 45. The first limiting member 44 and the second limiting member 45 are both used to restrict the movement of the stop assembly 5 along the axial direction of the housing 1.

[0079] Further, see Appendix Figure 4 and attached Figure 5As shown, the drive assembly 6 is mounted on the housing 1 and includes a screw 61. The screw 61 extends along the axial direction of the housing 1. One end of the screw 61 facing the first valve port 14 is connected to the second valve needle 3. The screw 61 passes through the limiting assembly 4 and the stop assembly 5. The screw 61 is threadedly connected to the limiting assembly 4 and fixedly connected to the stop assembly 5. When the screw 61 rotates, because the limiting assembly 4 is fixed inside the housing 1 and the screw 61 is threadedly engaged with the limiting assembly 4, the screw 61 will also move along the axial direction of the housing 1 under the drive of the limiting assembly 4. The stop assembly 5 is fixedly connected to the screw 61, so that the stop assembly 5 moves along the axial direction of the housing 1 together with the screw 61.

[0080] During the process of the screw 61 driving the stop assembly 5 to move along the axial direction of the housing 1, the anti-rotation lug 521 and the anti-rotation groove 43 cooperate to guide and position the stop assembly 5, ensuring that the stop assembly 5 moves only along the axial direction of the housing 1. This prevents the stop assembly 5 from rotating and not moving along the axial direction of the housing 1, thereby preventing the electronic expansion valve 100 from failing, ensuring the reliability and stability of the electronic expansion valve 100, and extending the service life of the electronic expansion valve 100.

[0081] It should be noted that the reference appendix Figure 3 As shown, the drive assembly 6 also includes a coil component 62, a rotor component 63, and a guide member 64. The coil component 62 is sleeved outside the housing 1, and the rotor component 63 is disposed inside the housing 1. The coil component 62 is located radially outside the rotor component 63 and is disposed opposite to at least a portion of the rotor component 63, for driving the rotor component 63 to rotate. The guide member 64 is fixed inside the rotor component 63, and the screw 61 passes through the guide member 64 along its length (see attached figure). Figure 3 One end of the rotor (in direction a) is welded to the guide 64, so that the rotor component 63, the guide 64 and the screw 61 rotate synchronously. The screw 61 passes through both the guide 64 and the stop assembly 5. The guide 64 and the stop assembly 5 are spaced apart along the axial direction of the housing 1, which can prevent the screw 61 from deviating during rotation and ensure the normal rotation of the screw 61.

[0082] It is understandable that, such as Figure 3 , Figure 4 and Figure 5As shown, when the coil component 62 is energized, it drives the rotor component 63 to rotate. Since the screw 61 is fixedly connected to the rotor component 63 via the guide 64, the rotor component 63 drives the screw 61 to rotate together. The screw 61 and the limiting component 4 are threaded together to form a threaded pair. The limiting component 4 is fixed to the housing 1, causing the screw 61 to move along the axial direction of the housing 1, which in turn drives the rotor component 63 to move along the axial direction of the housing 1. During the movement of the rotor component 63 along the axial direction of the housing 1, at least a portion of the rotor component 63 is opposite to the coil component 62 to ensure that the coil component 62 drives the rotor component 63 to rotate normally. Furthermore, driven by the screw 61, the stop component 5 moves along the axial direction of the housing 1 until the anti-rotation lug 521 abuts against the first limiting component 44 or the second limiting component 45, restricting the stop component 5 from continuing to move along the axial direction of the housing 1. Because the screw 61 is fixedly connected to the stop component 5, the screw 61 cannot continue to rotate, thus achieving the purpose of stopping.

[0083] Understandably, in existing technologies, valve core limiting is often achieved through the cooperation of slip rings and springs. However, this utility model uses the anti-rotation lug 521 to abut against the first limiting member 44 or the second limiting member 45, restricting the movement of the stop assembly 5 along the axial direction of the housing 1, thereby restricting the rotation of the screw 61 and achieving the limiting effect on the first valve needle 2 and the second valve needle 3. This can relatively reduce the length of the rotor component 63 moving along the axial direction of the housing 1, thereby relatively reducing the space left in the housing 1 for the rotor component 63 to move along the axial direction of the housing 1. This can reduce the overall height of the electronic expansion valve 100, make full use of the axial space of the electronic expansion valve 100, and facilitate the miniaturization of the electronic expansion valve 100 and reduce the cost of the electronic expansion valve 100.

[0084] Furthermore, because the limiting component 4 and the screw 61 are threadedly engaged, the axial height of the screw 61 can be reduced through multiple rotations with a small pitch. This effectively reduces the height caused by the cumulative effect of the wire diameter and pitch of the spring stop in the prior art, further reducing the height of the electronic expansion valve 100 and facilitating its miniaturization. Simultaneously, by eliminating the slip ring and spring design, the noise problem caused by the slip ring on the spring stop is solved, reducing the noise of the electronic expansion valve 100 during use and preventing the spring from breaking due to excessive force, thus relatively extending the service life of the electronic expansion valve 100.

[0085] Optionally, the threaded engagement between the limiting component 4 and the screw 61 is not limited to ordinary threads; it can also be a non-self-locking internal thread, trapezoidal thread, circular thread, or rectangular thread. It is understood that in existing technologies where the valve core is limited by a slip ring and spring, the nut is an injection-molded part, requiring high-quality materials, resulting in high cost and high material consumption. In contrast, at least a portion of the limiting component 4 in this invention is made of metal, requiring relatively lower-quality materials, resulting in lower cost and saving on the overall production cost of the electronic expansion valve 100. For example, the limiting component 4 can be a metal part or a combination of a metal part and an injection-molded part.

[0086] Further, see Appendix Figure 9 As shown, the fourth cavity 31 has a third elastic element 36, and the length direction of the third elastic element 36 (see attached diagram). Figure 9 One end of the valve (in direction a) abuts against the screw 61, and the other end abuts against the inner bottom wall of the fourth cavity 31. This valve is used to drive the screw 61 to move away from the second valve port 225. It can also generate a pre-tightening force when compressed, and reserve a set valve opening pulse so that the electronic expansion valve 100 can have sufficient sealing force to block the second valve port 225 when the power is off or when it is not running, thus preventing medium leakage.

[0087] It should be noted that the elastic force of the third elastic element 36 needs to be less than the axial force of the drive assembly 6 in order to ensure the normal opening of the electronic expansion valve 100.

[0088] In a further embodiment of this utility model, reference is made to the appendix. Figure 8 Appendix Figure 15 and attached Figure 16 As shown, the stop assembly 5 includes a fixed ring 51, a stop ring 52, and a stop bearing 53. The fixed ring 51 is located inside the limiting assembly 4 and is fixedly connected to the screw 61. The stop ring 52 is sleeved on the fixed ring 51. An anti-rotation lug 521 is located on the outer peripheral wall of the stop ring 52. The stop bearing 53 is located between the fixed ring 51 and the stop ring 52. The outer ring of the stop bearing 53 is fixed to the stop ring 52, and the inner ring is fixed to the fixed ring 51 and rotates synchronously. The stop bearing 53 is configured to satisfy both the need for the anti-rotation lug 521 on the stop ring 52 to cooperate with the anti-rotation groove 43 and the need for the fixed ring 51 and the screw 61 to rotate synchronously when the stop assembly 5 is assembled onto the limiting assembly 4. This ensures that the stop ring 52 moves only along the axial direction of the housing 1, while the fixed ring 51 moves along the axial direction of the screw 61 (see attached diagram). Figure 9 The movement in direction a) shown in the figure also rotates together with the screw 61, thereby realizing the assembly of the stop assembly 5 with the limit assembly 4 and the screw 61.

[0089] It is understandable that, such as Figure 4 , Figure 5 and Figure 7As shown, when the coil component 62 is energized, the coil component 62 drives the rotor component 63 to rotate. Since the screw 61 is fixedly connected to the rotor component 63 through the guide 64, the rotor component 63 drives the screw 61 to rotate together. The fixing ring 51 rotates together with the screw 61. Since the screw 61 is threadedly engaged with the limiting component 4, and the limiting component 4 is fixed on the housing 1, the screw 61 moves along the axial direction of the housing 1, thereby driving the stop component 5 to move along the axial direction of the housing 1 until the anti-rotation lug 521 abuts against the first limiting component 44 or the second limiting component 45, restricting the stop ring 52 from continuing to move along the axial direction of the housing 1. Since the screw 61 is fixedly connected to the fixing ring 51, the screw 61 cannot continue to rotate, thus achieving the purpose of stopping.

[0090] In a further embodiment of this utility model, reference is made to the appendix. Figure 15 As shown, the anti-rotation lugs 521 are multiple spaced apart along the circumferential direction of the stop assembly 5, and the anti-rotation grooves 43 are multiple corresponding to the multiple anti-rotation lugs 521. These spaced-apart grooves can limit the stop assembly 5 from rotating relative to the limiting assembly 4, preventing the stop ring 52 of the stop assembly 5 from rotating. This ensures that the stop assembly 5 is movable along the axial direction of the housing 1, thereby preventing the electronic expansion valve 100 from failing, ensuring the reliability and stability of the electronic expansion valve 100, and extending the service life of the electronic expansion valve 100. For example, the anti-rotation lugs 521 can be two, three, four, five, or six spaced apart along the circumferential direction of the stop assembly 5, and the anti-rotation grooves 43 can be two, three, four, five, or six corresponding to the multiple anti-rotation lugs 521.

[0091] In a specific example, see Appendix Figure 15 As shown, the anti-rotation lugs 521 are two spaced apart along the circumferential direction of the stop assembly 5. The two anti-rotation lugs 521 are located on opposite sides of the stop assembly 5. The anti-rotation grooves 43 are two corresponding to the two anti-rotation lugs 521. They can limit the stop assembly 5 from two spaced apart along the circumferential direction, further preventing the stop ring 52 of the stop assembly 5 from rotating relative to the limiting assembly 4. This ensures that the stop assembly 5 can move along the axial direction of the housing 1, preventing the electronic expansion valve 100 from failing, ensuring the reliability and stability of the electronic expansion valve 100, and extending the service life of the electronic expansion valve 100.

[0092] In a further embodiment of this utility model, reference is made to the appendix. Figure 4 Appendix Figure 5 and attached Figure 6As shown, the limiting component 4 includes a limiting post 41 and a nut 42. The limiting post 41 extends along the axial direction of the housing 1. The peripheral wall of the limiting post 41 has a groove that extends along the axial direction of the housing 1. One side of the groove along the axial direction of the housing 1 is open. The nut 42 is located on the open side of the groove and is used to seal the opening of the groove to define the anti-rotation groove 43. The inner wall of the groove facing away from the nut 42 is configured as a first limiting member 44. The end face of the nut 42 facing the first limiting member 44 is configured as a second limiting member 45. The screw 61 passes through both the limiting post 41 and the nut 42 and is threadedly connected to the nut 42. By making the limiting post 41 and the nut 42 separate parts, the manufacturing difficulty of the limiting component 4 can be reduced, and it is easier to assemble the stop component 5 onto the limiting component 4, thereby reducing the assembly difficulty of the electronic expansion valve 100.

[0093] In a specific example, such as Figure 6 As shown, the end of the limiting post 41 facing the first valve port 14 is provided with a groove, and the side of the groove facing the first valve port 14 is open. The nut 42 is provided on the side of the groove facing the first valve port 14 to limit the anti-rotation groove 43. The inner wall of the side of the groove away from the first valve port 14 is constructed as the first limiting member 44, and the end of the nut 42 away from the first valve port 14 is constructed as the second limiting member 45.

[0094] It should be noted that the reference appendix Figure 6 As shown, the limiting post 41 has a through hole 411, through which the screw 61 passes. This allows the limiting post 41 to radially limit the screw 61, preventing it from shifting during rotation and ensuring its normal rotation. This, in turn, prevents the rotor component 63 from shifting due to screw 61 shifting, thus avoiding friction between the rotor component 63 and the inner wall of the housing 1, and consequently preventing power loss. When assembling the limiting assembly 4, the limiting post 41 and the nut 42 are first pressed together, and then welded together to secure them, increasing the structural strength of the limiting assembly 4.

[0095] It should be noted that, as Figure 4 and Figure 6 As shown, when assembling the electronic expansion valve 100, the fixing ring 51, the stop ring 52, and the stop bearing 53 are first assembled together to form a complete stop assembly 5. Then, the screw 61 is installed into the nut 42. After the electronic expansion valve 100 completes the top pulse, the stop assembly 5 is sleeved onto the screw 61 from one end until the anti-rotation lug 521 abuts against the nut 42. Then, the fixing ring 51 of the stop assembly 5 is welded to the screw 61 and fixed into an integral structure. Finally, the limiting post 41 is sleeved onto the screw 61 and fixedly connected to the nut 42.

[0096] Of course, this utility model is not limited to this. The anti-rotation groove 43, the first limiting member 44 and the second limiting member 45 can also be composed of other forms of limiting posts 41 and nuts 42. For example, the groove can also be provided on the outer peripheral wall of the nut 42. The groove extends along the axial direction of the housing 1 and is open on one side along the axial direction of the housing 1. The limiting post 41 is provided on the open side of the groove to seal the opening of the groove and define the anti-rotation groove 43. The inner wall of the groove on the side away from the limiting post 41 is configured as a second limiting member 45. The end face of the limiting post 41 facing the second limiting member 45 is configured as a first limiting member 44. The groove can also include a first groove and a second groove. The first groove is provided on the peripheral wall of the limiting post 41, and the second groove is provided on the outer peripheral wall of the nut 42. Both the first groove and the second groove extend along the axial direction of the housing 1 and are open on one side facing each other. The first groove and the second groove together define the anti-rotation groove 43. The inner wall of the first groove on the side facing the second groove is configured as a first limiting member 44, and the inner wall of the second groove on the side facing the first groove is configured as a second limiting member 45.

[0097] It should be noted that when the limiting component 4 is a combination of metal and injection molded parts, the limiting post 41 can be a metal part and the nut 42 can be an injection molded part; or the nut 42 itself can be composed of both metal and plastic materials. For example, the part of the nut 42 that contacts the limiting post 41 is made of metal, and the threaded part of the nut 42 is formed by injection molding.

[0098] In a further embodiment of this utility model, reference is made to the appendix. Figure 4 and attached Figure 5 As shown, a first elastic element 46 is provided between the limiting component 4 and the first valve needle 2, which is used to drive the first valve needle 2 to move towards the first valve port 14, ensuring the sealing of the first valve needle 2 with respect to the first valve port 14. For example, the length direction of the first elastic element 46 (see attached figure) Figure 4 The two ends of the first elastic element 46 in the direction shown in a can abut against the nut 42 and the guide sleeve 21 respectively, which can ensure that the contact area at both ends of the first elastic element 46 in the length direction is sufficient and ensure the reliability of the assembly of the first elastic element.

[0099] Further, see Appendix Figure 4 and attached Figure 5 As shown, a second elastic element 47 is provided between the limiting component 4 and the second valve needle 3. The length direction of the second elastic element 47 (see attached diagram) Figure 4The two ends of the spring (in direction a) abut against the nut 42 and the second valve needle 3, respectively, to drive the second valve needle 3 to move toward the second valve port 225, ensuring the sealing of the second valve needle 3 with respect to the second valve port 225, and eliminating thread clearance of the second valve needle 3 during the opening process. Preferably, the second elastic element 47 is a pagoda-shaped spring. The end face of the nut 42 facing the first valve port 14 has a receiving groove. One end of the pagoda-shaped spring is engaged in the receiving groove. The receiving groove can guide the pagoda-shaped spring, facilitate the installation of the pagoda-shaped spring, ensure the compression and elongation of the pagoda-shaped spring along the axial direction of the housing 1, and prevent the pagoda-shaped spring from becoming skewed.

[0100] It should be noted that the sum of the elastic force of the first elastic element 46 and the elastic force of the second elastic element 47 must be less than the axial force of the drive assembly 6 in order to ensure the normal opening of the electronic expansion valve 100.

[0101] Understandably, the process of the electronic expansion valve 100 gradually opening is as follows: the screw 61 drives the bearing to move away from the second valve port 225, the third elastic element 36 gradually resets, and then the screw 61 continues to move away from the second valve port 225, driving the second valve needle 3 to move away from the first valve port 14, slowly compressing the second elastic element 47, and the second valve port 225 opens. At this time, the medium can enter the first cavity 11 through the first connecting hole 13, and flow into the third cavity 223 through the second connecting hole 224, and then flow out of the first valve port 14 through the second valve port 225. Alternatively, the medium can pass through the first valve port 14 and the second valve port 225 in sequence into the third cavity 223, enter the first cavity 11 through the second connecting hole 224, and finally flow out through the first connecting hole 13.

[0102] The screw 61 continues to drive the second valve needle 3 to move away from the first valve port 14 until the limiting ring 33 and the limiting stop ring 26 stop on the surface facing the first valve port 14. The screw 61 drives the first valve needle 2 and the second valve needle 3 to move together away from the first valve port 14 to open the first valve port 14 until the anti-rotation lug 521 of the stop assembly 5 abuts against the first limiting member 44. At this time, the first valve needle 2 and the second valve needle 3 will not move relative to each other in the axial direction of the housing 1, thus realizing the complete opening of the first valve port 14. The medium can flow into the first cavity 11 from one of the first connecting hole 13 and the first valve port 14, and flow out from the other.

[0103] The process of the electronic expansion valve 100 gradually closing: When the first valve needle 2 opens the first valve port 14, the first connecting hole 13 and the first valve port 14 are connected through the first cavity 11. The medium can flow into the first cavity 11 from one of the first connecting hole 13 and the first valve port 14 and flow out from the other. At this time, the limiting ring 33 and the limiting retaining ring 26 stop the surface facing the first valve port 14. The screw 61 moves towards the direction close to the first valve port 14. The screw 61 drives the first valve needle 2 and the second valve needle 3 to move towards the direction close to the first valve port 14. At this time, the first valve needle 2 and the second valve needle 3 will not move relative to each other in the axial direction of the housing 1.

[0104] When the first valve needle 2 blocks the first valve port 14, the first valve needle 2 can no longer move toward the first valve port 14. The screw 61 continues to push the second valve needle 3 toward the direction closer to the first valve port 14. The second elastic element 47 gradually resets, and the limiting ring 33 gradually separates from the limiting retaining ring 26. At this time, the medium can enter the first cavity 11 through the first connecting hole 13, and flow into the third cavity 223 through the second connecting hole 224, and then flow out of the first valve port 14 through the second valve port 225. Alternatively, the medium can pass through the first valve port 14 and the second valve port 225 in sequence into the third cavity 223, enter the first cavity 11 through the second connecting hole 224, and finally flow out through the first connecting hole 13. When the second valve needle 3 blocks the second valve port 225, the second valve needle 3 can no longer move toward the second valve port 225. The screw 61 is over-tightened and compresses the third elastic element 36, achieving complete blocking of the second valve port 225.

[0105] Other configurations and operations of the electronic expansion valve 100 according to embodiments of the present invention are known to those skilled in the art and will not be described in detail here.

[0106] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0107] Although embodiments of the present invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the claims and their equivalents.

Claims

1. An electronic expansion valve characterized by, The utility model relates to a valve needle assembly, which comprises: a housing (1) having a first cavity (11), a second cavity (12), a first communication hole (13) and a first valve port (14), the first cavity (11) and the second cavity (12) are arranged in the axial direction of the housing (1), the first communication hole (13) is arranged on the peripheral wall of the housing (1) and communicates with the first cavity (11), and the first valve port (14) is arranged at one end of the first cavity (11) away from the second cavity (12); a first valve needle (2) arranged in the housing (1) and partially extending into the first cavity (11), the first valve needle (2) is movable in the axial direction of the housing (1) to block the first valve port (14), the first valve needle (2) has a third cavity (223) and a first flow channel (24) therein, the axial end face of the first valve needle (2) away from the second cavity (12) has a second valve port (225) communicating with the third cavity (223), the peripheral wall of the first valve needle (2) has a second communication hole (224) communicating with the third cavity (223) and the first cavity (11), the first flow channel (24) communicates with the first valve port (14), and the first flow channel (24) is spaced apart from the third cavity (223) and the second communication hole (224); a second valve needle (3) arranged in the first valve needle (2), part of the second valve needle (3) is arranged in the third cavity (223), the second valve needle (3) is movable in the axial direction of the housing (1) to block the second valve port (225), the inner peripheral wall of the first valve needle (2) and the outer peripheral wall of the second valve needle (3) define a second flow channel (25), the second flow channel (25) is located on the side of the first flow channel (24) close to the second cavity (12), and the second flow channel (25) communicates the first flow channel (24) and the second cavity (12).

2. The electronic expansion valve according to claim 1, characterized in that The inner peripheral wall of the first valve needle (2) has a guide protruding section (23) extending in the circumferential direction of the first valve needle (2), the guide protruding section (23) has a first notch (231) penetrating the guide protruding section (23) in the axial direction of the housing (1).

3. The electronic expansion valve according to claim 2, characterized in that The first notch (231) is a plurality of notches arranged at intervals in the circumferential direction of the guide protruding section (23).

4. The electronic expansion valve according to claim 1, wherein The first flow channel (24) comprises a first sub-flow channel (241) and a second sub-flow channel (242), and the first valve needle (2) comprises: A guide sleeve (21) and a valve core (22) are arranged and connected along the axial direction of the housing (1), the valve core (22) is located on the side of the guide sleeve (21) facing the first valve port (14), the third cavity (223), the second valve port (225) and the second communication hole (224) are all arranged on the valve core (22), the inner peripheral wall of the guide sleeve (21) and the outer peripheral wall of the second valve needle (3) define the second flow channel (25), the first sub-flow channel (241) is formed between the valve core (22) and the guide sleeve (21), the first sub-flow channel (241) communicates with the second flow channel (25), the second sub-flow channel (242) is arranged on the valve core (22) and penetrates the valve core (22) along the axial direction of the housing (1), in the circumferential direction of the first valve needle (2), the second sub-flow channel (242) is spaced apart from the second communication hole (224), and the second sub-flow channel (242) communicates with the first sub-flow channel (241) and the first valve port (14).

5. The electronic expansion valve according to claim 4, wherein The first sub-flow channel (241) is annular and extends along the circumferential direction of the second valve needle (3), and the second sub-flow channel (242) is spaced apart along the circumferential direction of the first valve needle (2).

6. The electronic expansion valve according to claim 1, wherein Further comprising: A limiting assembly (4) is arranged in the second cavity (12) and extends along the axial direction of the housing (1), the limiting assembly (4) has an anti-rotation groove (43), a first limiting piece (44) and a second limiting piece (45), the anti-rotation groove (43) is arranged on the peripheral wall of the limiting assembly (4) and extends along the axial direction of the housing (1), and the first limiting piece (44) and the second limiting piece (45) are respectively located at both ends of the extension direction of the anti-rotation groove (43); A stop assembly (5) is arranged in the limiting assembly (4) and can move along the axial direction of the housing (1), the outer peripheral wall of the stop assembly (5) has an anti-rotation lug (521) matched with the anti-rotation groove (43), the anti-rotation lug (521) is located between the first limiting piece (44) and the second limiting piece (45), and the first limiting piece (44) and the second limiting piece (45) are both used for limiting the movement of the stop assembly (5) along the axial direction of the housing (1); A driving assembly (6) is arranged on the housing (1) and includes a screw rod (61), the screw rod (61) extends along the axial direction of the housing (1), one end of the screw rod (61) facing the first valve port (14) is connected with the second valve needle (3), the screw rod (61) penetrates the limiting assembly (4) and the stop assembly (5), the screw rod (61) is threadedly connected with the limiting assembly (4) and fixedly connected with the stop assembly (5).

7. The electronic expansion valve according to claim 6, characterized in that The stop component (5) comprises: a fixing ring (51) arranged in the limiting component (4), and the fixing ring (51) is fixedly connected with the screw rod (61); a stop ring (52) sleeved on the fixing ring (51), and the anti-rotation lug (521) is arranged on the outer circumferential wall of the stop ring (52); a stop bearing (53) arranged between the fixing ring (51) and the stop ring (52).

8. The electronic expansion valve according to claim 6, wherein The anti-rotation lugs (521) are spaced apart along the circumferential direction of the stop component (5), and the anti-rotation grooves (43) are one-to-one corresponding to the plurality of anti-rotation lugs (521).

9. The electronic expansion valve according to claim 6, wherein The limiting component (4) comprises: a limiting column (41) extending along the axial direction of the shell (1), and the circumferential wall of the limiting column (41) has a groove extending along the axial direction of the shell (1), and the groove is open on one side along the axial direction of the shell (1); a nut (42) arranged on the open side of the groove for blocking the open end of the groove to define the anti-rotation groove (43), and the inner wall of the side of the groove away from the nut (42) is configured as the first limiting piece (44), and the end face of the nut (42) facing the first limiting piece (44) is configured as the second limiting piece (45), and the screw rod (61) is arranged in the limiting column (41) and the nut (42) and is threadedly connected with the nut (42).

10. The electronic expansion valve according to claim 6, wherein The limiting component (4) and the first valve needle (2) are provided with a first elastic piece (46); And / or, the limiting component (4) and the second valve needle (3) are provided with a second elastic piece (47).

Images