Electronic expansion valve

Abstract

This utility model discloses an electronic expansion valve, including a rotor assembly, a valve body assembly, and a valve needle. The rotor assembly includes a magnetic rotor and a guide shaft. The valve body assembly includes a valve body and a valve port seat. One end of the valve port seat is disposed within the valve body and forms a valve port. The magnetic rotor and the guide shaft drive the first end of the valve needle to approach or move away from the valve port to adjust the opening degree of the expansion valve. A helical guide rail is formed on the outer wall of the guide shaft, which is used to cooperate with a slip ring. The magnetic rotor is injection molded on the outside of the guide shaft and the valve needle, fixing the guide shaft and the valve needle together as one unit. The magnetic rotor, the guide shaft, and the valve needle are coaxial and move synchronously. This utility model has the advantages of convenient assembly and high control precision.

Description

Technical Field

[0001] This utility model relates to the field of valve technology, specifically to an electronic expansion valve. Background Technology

[0002] Electronic expansion valves utilize electrical signals generated by the regulated parameters (such as superheat or pressure) to control the voltage or current applied to the expansion valve, thereby regulating the refrigerant supply. Electronic expansion valves enable continuous, high-precision flow regulation and are widely used in refrigeration systems to control refrigerant flow and maintain evaporator performance.

[0003] Electronic expansion valves in related technologies are prone to inaccurate flow regulation during use. Utility Model Content

[0004] This utility model aims to solve one of the technical problems in related technologies to a certain extent. To this end, this utility model provides an electronic expansion valve, which has the advantages of convenient assembly and high control precision.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: an electronic expansion valve, comprising a rotor assembly, a valve body assembly, and a valve needle. The rotor assembly includes a magnetic rotor and a guide shaft. The valve body assembly includes a valve body and a valve port seat. One end of the valve port seat is disposed within the valve body and forms a valve port. The magnetic rotor and the guide shaft drive the first end of the valve needle to approach or move away from the valve port to adjust the opening degree of the expansion valve. A helical guide rail is formed on the outer wall of the guide shaft. The helical guide rail is used to cooperate with a slip ring. The magnetic rotor is injection molded on the outside of the guide shaft and the valve needle, and the guide shaft and the valve needle are fixedly connected as a whole. The magnetic rotor, the guide shaft, and the valve needle are coaxial and move synchronously.

[0006] In this technical solution, the guide shaft and valve needle are fixedly connected by the injection molding of the magnetic rotor, so that the magnetic rotor, guide shaft and valve needle are integrated into a single structure. This allows the guide shaft and valve needle to be fixedly connected simultaneously during the molding process of the magnetic rotor, simplifying the production process. Moreover, the integrated structure and coaxial arrangement of the three components can avoid assembly errors and improve the control accuracy during use.

[0007] Furthermore, the guide shaft includes a shaft body and a bearing seat. The outer wall of the shaft body is formed with the helical guide rail. The magnetic rotor includes a cylindrical body and a connecting part. The cylindrical body is sleeved outside the shaft body. The connecting part is located at the end of the cylindrical body and outside the bearing seat. A first mating part is formed on the outer wall of the bearing seat. The connecting part has a second mating part that mates with the first mating part. The first and second mating parts cooperate with each other to restrict the relative circumferential rotation of the guide shaft and the magnetic rotor.

[0008] Furthermore, the first mating part includes a first plane disposed on the outer wall of the bearing portion, and the second mating part includes a second plane disposed on the inner wall of the connecting part, with the first plane and the second plane being fitted together.

[0009] Furthermore, the first mating part includes a mating groove disposed on the outer wall of the bearing seat part, and the second mating part includes a mating protrusion disposed on the connecting part. The mating protrusion is engaged in the mating groove, and the first plane and the mating groove are arranged circumferentially around the axis of the bearing seat part.

[0010] Furthermore, a central hole is formed at the center of the guide shaft, and the second end of the valve needle is inserted into the central hole. A first annular protrusion is formed on the outer wall of the valve needle, and a second annular protrusion is formed on the bottom surface of the guide shaft. The first annular protrusion is disposed inside the second annular protrusion and forms a gap with the bottom surface of the guide shaft. An injection molding space is formed between the first annular protrusion, the second annular protrusion, and the bottom surface of the guide shaft. A portion of the magnetic rotor is formed within the injection molding space to achieve a fixed connection between the magnetic rotor, the guide shaft, and the valve needle.

[0011] Furthermore, an annular groove is formed on the outer wall of the valve needle, a portion of which is placed inside the central hole and another portion outside the central hole. The first annular protrusion is disposed on the side of the annular groove outside the central hole. The annular groove communicates with the injection molding space. A portion of the magnetic rotor is formed inside the annular groove. A limiting platform is formed inside the central hole, which is opposite to the end of the valve needle, to limit the relative position of the valve needle and the guide shaft in the axial direction.

[0012] Furthermore, a third plane is formed on the outer wall of the first annular protrusion, and a fourth plane that fits with the third plane is injection molded on the magnetic rotor.

[0013] Furthermore, the valve body assembly also includes a nut seat, which is fixed in the valve body and spaced apart from the valve port seat. A mounting through hole is formed on the nut seat, through which the valve needle passes. An external thread is formed on the outer wall of the valve needle, and an internal thread that mates with the external thread is formed on the inner wall of the mounting through hole. The valve needle is threadedly connected to the mounting through hole.

[0014] Furthermore, the guide rail shaft is made of plastic and injection molded.

[0015] Furthermore, a conical mating section is formed at one end of the valve needle near the valve port, and there is a gap between the conical mating section and the valve port.

[0016] These features and advantages of this utility model will be disclosed in detail in the following specific embodiments and accompanying drawings. The preferred embodiments or means of this utility model will be shown in detail in conjunction with the accompanying drawings, but this is not intended to limit the technical solution of this utility model. In addition, each of these features, elements and components appearing in the following text and drawings is multiple and is labeled with different symbols or numbers for convenience, but all represent parts with the same or similar structure or function. Attached Figure Description

[0017] The present invention will be further described below with reference to the accompanying drawings:

[0018] Figure 1 This is a front sectional view of the expansion valve according to one embodiment of the present invention;

[0019] Figure 2 This utility model Figure 1 Enlarged view of point A in the middle;

[0020] Figure 3 This is a structural diagram of the guide shaft according to one embodiment of the present invention;

[0021] Figure 4 This is a structural diagram of the valve needle according to one embodiment of the present invention;

[0022] Figure 5 This is a structural diagram of a magnetic rotor according to one embodiment of the present invention;

[0023] Figure 6 This utility model Figure 1 Sectional view along the BB direction;

[0024] Figure 7 This is a structural diagram showing the connection between the magnetic rotor, guide shaft, and valve needle in one embodiment of the present invention.

[0025] Figure 8 This is a structural diagram of the guide shaft of one embodiment of the present utility model.

[0026] in,

[0027] 10. Rotor assembly; 11. Magnetic rotor; 111. Cylindrical section; 112. Connecting section;

[0028] 12. Guide rail shaft; 121. Shaft body;

[0029] 122, Shaft seat portion; 1221, First plane; 1222, Mating groove;

[0030] 123. Spiral guide rail; 124. Center hole; 1241. Limiting platform; 125. Balancing air hole; 126. Second annular protrusion;

[0031] 13. Slip ring; 14. Shift fork; 15. Housing;

[0032] 20. Valve body assembly; 21. Valve body; 22. Valve port seat; 23. Valve port; 24. Nut seat; 241. Internal thread;

[0033] 30. Valve needle; 31. First annular protrusion; 311. Third plane; 32. Annular groove; 33. External thread; 34. Conical mating section;

[0034] 41. Main tube; 42. Branch tube. Detailed Implementation

[0035] The embodiments of this utility model are described in detail below. Examples of these 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 are intended to explain this utility model and should not be construed as limiting it.

[0036] The terms "an embodiment," "example," or "trademark" used in this specification refer to a particular feature, structure, or characteristic described in connection with the embodiment itself that may be included in at least one embodiment disclosed in this utility model. The phrase "in an embodiment" appearing in various places throughout the specification does not necessarily refer to the same embodiment.

[0037] In existing technologies, the magnetic rotor in expansion valves is generally designed to be assembled with the guide shaft and the valve needle. This requires the guide shaft to be installed with the valve needle and the magnetic rotor to be installed with the guide shaft during assembly. This involves many assembly steps and is prone to assembly errors, which can lead to errors during use and affect the accuracy of the valve body.

[0038] Based on this, as one embodiment of the present utility model, see the appendix. Figures 1 to 8 An electronic expansion valve is disclosed, comprising a rotor assembly 10, a valve body assembly 20, and a valve needle 30. The rotor assembly 10 includes a magnetic rotor 11 and a guide shaft 12. The valve body assembly 20 includes a valve body 21 and a valve seat 22. One end of the valve seat 22 is disposed inside the valve body 21 and forms a valve port 23. The magnetic rotor 11 and the guide shaft 12 drive the first end of the valve needle 30 to approach or move away from the valve port 23 to adjust the opening of the expansion valve. A spiral guide rail 123 is formed on the outer wall of the guide shaft 12. The spiral guide rail 123 is used to cooperate with a slip ring 13. The magnetic rotor 11 is injection molded on the outside of the guide shaft 12 and the valve needle 30, and the guide shaft 12 and the valve needle 30 are fixedly connected as a whole. The magnetic rotor 11, the guide shaft 12, and the valve needle 30 are coaxial and move synchronously.

[0039] In this embodiment, the electronic expansion valve is a fully closed valve body 21 with flow. In actual use, the rotor assembly 10 is used to control the movement of the valve needle 30. The rotation of the magnetic rotor 11 drives the rotation of the guide shaft 12, which in turn drives the movement of the valve core.

[0040] In this embodiment, the guide shaft 12 is equipped with a spiral guide rail 123. The guide shaft 12 is made of plastic, and the spiral guide rail 123 and the guide shaft 12 are injection molded together. Compared with the assembly and connection structure of the spiral guide rail 123 and the guide shaft 12 in related technologies, it can simplify production efficiency and installation efficiency.

[0041] In this embodiment, the spiral guide rail 123 cooperates with the slip ring 13. During use, the expansion valve also includes a fork. Under the blocking action of the fork 14, the slip ring 13 limits the movement of the guide rail shaft 12 to two extreme positions, ensuring the stability of the movement of the guide rail shaft 12.

[0042] In this embodiment, the magnetic rotor 11 is injection molded. In actual installation, the guide shaft 12 and valve needle 30 are pre-positioned in the injection mold, and then the magnetic rotor 11 is injection molded on the outside of the guide shaft 12 and valve needle 30. The injection molding of the magnetic rotor 11 naturally forms a structure that is compatible with the guide shaft 12 and valve needle 30. It can also achieve a good connection between the magnetic rotor 11, the guide shaft 12 and the valve needle 30. That is, the magnetic rotor 11, the guide shaft 12 and the valve needle 30 are formed into a fixed structure in one go by injection molding without the need for subsequent welding or other related processes. This greatly simplifies the assembly process, thereby greatly reducing installation errors and improving the accuracy of the expansion valve.

[0043] Compared with the structure in related technologies where multiple separate components (guide shaft 12, spiral guide rail 123, magnetic rotor 11, rotor support seat, valve needle 30, etc.) are assembled into one piece, this embodiment greatly simplifies the assembly process and also helps to reduce the assembly error of magnetic rotor 11, guide shaft 12 and valve needle 30, ensuring the coaxiality of the three, thereby enabling precise adjustment of the expansion valve opening.

[0044] Furthermore, compared to the expansion valve in the related art, the expansion valve in this embodiment omits the spring structure, and the connection structure between the various components is also changed accordingly. In this embodiment, the guide shaft 12 is directly and fixedly connected to the valve needle 30. Compared to the structure in the related art where the guide shaft 12 is connected to the valve needle 30 through a spring structure (spring support seat and spring), the number of expansion valve components is reduced. Moreover, the connection relationship between the guide shaft 12 and the valve needle 30 is improved from being relatively movable to being fixedly connected, which improves the stability of the overall structure and reduces the unavoidable assembly errors of multiple components during the assembly process.

[0045] Furthermore, this embodiment uses injection molding to connect the magnetic rotor 11, guide shaft 12, and valve needle 30 into a single structure, which can better adapt to the shape and structure design of different components, making the strength of the connection part 112 more reliable, thereby improving the service life of the expansion valve.

[0046] In this embodiment, the rotor assembly 10 of the expansion valve also includes a housing 15, which is fixedly connected to one end of the valve body 21 and forms an installation cavity. In use, the magnetic rotor 11, guide shaft 12, slip ring 13 and shift fork are all arranged in the installation cavity inside the housing 15.

[0047] The expansion valve in this embodiment also includes a main pipe body 41 and a branch pipe body 42. The main pipe body 41 is fixedly connected to one end of the valve body 21 relative to the outer shell 15. A branch pipe connection port is provided on the side wall of the valve body 21. One end of the branch pipe body 42 is connected to the side wall of the valve body 21, and the branch pipe body 42 is connected to the branch pipe connection port.

[0048] As one embodiment of this utility model, see the appendix. Figure 2 , 3 The guide shaft 12 includes a shaft body 121 and a bearing seat 122. The spiral guide rail 123 is formed on the shaft body 121, and a first mating part is formed on the outer wall of the bearing seat 122. The magnetic rotor 11 includes a cylindrical body 111 and a connecting part 112. The cylindrical body 111 is the main part of the magnetic rotor 11 that rotates under the action of a magnetic field. The connecting part 112 is disposed at the end of the cylindrical body 111. The shaft body 121 is disposed inside the cylindrical body 111. The connecting part 112 is disposed around the bearing seat 122 and forms a second mating part that mates with the first mating part. The first mating part and the second mating part are used to limit the relative circumferential rotation of the guide shaft 12 and the magnetic rotor 11.

[0049] In this embodiment, the guide shaft 12 includes a shaft body 121 and a shaft seat 122. In actual use, a spiral guide rail 123 is formed on the shaft body 121 and used in conjunction with the slip ring 13. The shaft seat 122 is used to directly and fixedly connect to the magnetic rotor 11. Compared with the structure of connecting the magnetic rotor 11 through the rotor connecting seat in the related technology, the rotor connecting seat component is reduced (simplifying the overall structure of the expansion valve). Moreover, during the connection process, the overall assembly does not require the use of connecting parts.

[0050] In this embodiment, the connecting part 112 of the magnetic rotor 11 mainly serves a connecting function. In the design, the connecting part 112 is injection molded on the outside of the valve needle 30 and the guide shaft 12, and is directly connected to the valve needle 30 and the guide shaft 12.

[0051] During use, the rotation of the magnetic rotor 11 drives the rotation of the guide shaft 12, which generates a certain torque between them. To ensure that the magnetic rotor 11 and the guide shaft 12 do not rotate relative to each other during use, i.e., the magnetic rotor 11 and the guide shaft 12 are relatively fixed in the circumferential direction, this embodiment provides a first mating part on the shaft seat 122 and a second mating part on the connecting part 112. The first mating part and the second mating part cooperate with each other to ensure that the magnetic rotor 11 and the guide shaft 12 are relatively fixed in the circumferential direction, thereby improving the torsional strength during rotation.

[0052] In this embodiment, the specific structure of the first mating part and the second mating part is not specifically limited. In actual setting, the first mating part and the second mating part can be set as a planar mating structure (flat mating structure), a slot-protrusion mating structure, etc. Of course, the mating part of the connecting part 112 and the bearing part 122 can also be set as a non-circular shape, as long as the magnetic rotor 11 and the guide shaft 12 are relatively fixed in the circumference and can rotate synchronously.

[0053] As one embodiment of this utility model, see the appendix. Figure 3 The first mating part includes a first plane 1221 disposed on the outer wall of the bearing portion 122, and the second mating part includes a second plane disposed on the inner wall of the connecting portion 112. The first plane 1221 and the second plane are fitted together.

[0054] In this embodiment, a first plane 1221 is provided on the outer wall of the bearing seat 122. In actual installation, the first plane 1221 can be provided in multiple ways, and the multiple first planes 1221 can be distributed circumferentially around the axis of the bearing seat 122.

[0055] In this embodiment, during injection molding, the connecting part 112 can naturally be injection molded into the inner wall of the connecting part 112 to form a second plane that cooperates with the first plane 1221. In this way, the magnetic rotor 11 and the guide shaft 12 can be relatively fixed in the circumferential direction through the cooperation of the first plane 1221 and the second plane.

[0056] As one embodiment of this utility model, see the appendix. Figure 3 The first mating part includes a mating groove 1222 disposed on the outer wall of the bearing portion 122, and the second mating part includes a mating protrusion disposed on the inner wall of the connecting portion 112. The mating protrusion is engaged in the mating groove 1222, and the first plane 1221 and the mating groove 1222 are arranged circumferentially around the axis of the bearing portion 122.

[0057] In this embodiment, a mating groove 1222 is provided on the outer wall of the bearing seat portion 122. The number of mating grooves 1222 can be set to one or more. When there are multiple mating grooves 1222, the multiple mating grooves 1222 can be distributed circumferentially around the axis of the bearing seat portion 122, so that the connecting portion 112 and the bearing seat portion 122 form a circumferential fit, forming a more stable fit structure.

[0058] In this embodiment, during injection molding, the connecting part 112 of the magnetic rotor 11 can automatically fill into the mating groove 1222 to form a mating protrusion and fill the mating groove 1222. The mating protrusion and the mating groove 1222 form a fitting embedding structure, which can also achieve the relative fixation of the magnetic rotor 11 and the guide shaft 12 in the circumferential direction.

[0059] In the actual installation of the expansion valve in this embodiment, a first plane 1221 and a mating groove 1222 can be formed simultaneously on the outer side wall of the shaft seat portion 122, which can provide a more stable mating structure.

[0060] Of course, it is conceivable that a protruding structure can also be formed on the outer wall of the bearing seat 122, and the connecting part 112 can form a groove structure that matches the protrusion on the bearing seat 122 during the injection molding process, which can also improve the torsional strength.

[0061] As one embodiment of this utility model, see the appendix. Figure 1 , 2 3, 6, 7, 8, A central hole 124 is formed in the center of the guide shaft 12. The second end of the valve needle 30 is inserted into the central hole 124. A first annular protrusion 31 is formed on the outer wall of the valve needle 30. A second annular protrusion 126 is formed on the bottom surface of the guide shaft 12. The first annular protrusion 31 is disposed inside the second annular protrusion 126 and forms a gap with the bottom surface of the guide shaft 12. An injection molding space is formed between the first annular protrusion 31, the second annular protrusion 126, and the bottom surface of the guide shaft 12. A part of the magnetic rotor 11 is formed in the injection molding space to achieve a fixed connection between the magnetic rotor 11, the guide shaft 12, and the valve needle 30.

[0062] This embodiment defines the mating structure between the valve needle 30, the guide shaft 12, and the magnetic rotor 11. The guide shaft 12 has a central hole 124. During production, after the guide shaft 12 and the valve needle 30 are processed, before the magnetic rotor 11 is injection molded, the guide shaft 12 and the valve needle 30 are pre-assembled (one end of the valve needle 30 is inserted into the central hole 124 of the guide shaft 12) and placed into the injection mold. Then, the magnetic rotor 11 is injection molded on the outside of the guide shaft 12 and the valve needle 30.

[0063] In this embodiment, a second annular protrusion 126 is formed on the bottom surface of the guide shaft 12, and a first annular protrusion 31 is formed on the valve needle 30. The outer diameter of the first annular protrusion 31 is larger than the diameter of the central hole 124, so that the first annular protrusion 31 has a portion that is opposite to and spaced apart from the bottom surface of the guide shaft 12 (as shown in the attached figure). Figure 2 As shown, during the injection molding of the magnetic rotor 11, magnetic powder automatically fills the injection space formed between the first annular protrusion 31, the second annular protrusion 126, and the bottom surface of the guide shaft 12. After molding, the magnetic rotor 11, the guide shaft 12, and the valve needle 30 are connected together at this location (within the injection space).

[0064] In this embodiment, the first annular protrusion 31 and the second annular protrusion 126 are configured to provide better support for the magnetic powder during the injection molding process, making the structure of the magnetic rotor 11 more stable after injection molding.

[0065] In this embodiment, a balance air hole 125 is provided on the side wall of the shaft part 121. The balance air hole 125 is connected to the center hole 124. During operation, when the guide shaft 12 moves back and forth, the gas at both ends of the guide shaft 12 can flow quickly through the balance air hole 125 to avoid the problem of unstable movement caused by air pressure.

[0066] To fix the valve needle 30 axially relative to the guide rail shaft 12 and the magnetic rotor 11, see Appendix Figure 4 In one embodiment of the present invention, an annular groove 32 is formed on the outer wall of the valve needle 30. A portion of the annular groove 32 is placed inside the central hole 124, and another portion is placed outside the central hole 124. The first annular protrusion 31 is disposed on the side of the annular groove 32 outside the central hole 124. The annular groove 32 is connected to the injection molding space. A portion of the magnetic rotor 11 is formed in the annular groove 32. A limiting platform 1241 is formed in the central hole 124, which is opposite to the end of the second end of the valve needle 30, so as to limit the relative position of the valve needle 30 and the guide shaft 12 in the axial direction.

[0067] This embodiment defines a structure for axially limiting the valve needle 30. An annular groove 32 is formed on the outer wall of the valve needle 30. When the magnetic rotor 11 is injection molded, magnetic powder will fill the annular groove 32. That is, after molding, a part of the magnetic rotor 11 will fill the annular groove 32 (a part of the inner wall of the connecting part 112), forming a mutually engaging structure so that the magnetic rotor 11 and the annular groove 32 will not move relative to each other axially.

[0068] In this embodiment, a portion of the annular groove 32 is placed inside the central hole 124, and another portion is placed outside the central hole 124. This allows part of the magnetic rotor 11 to fill into the central hole 124 during molding, achieving axial relative fixation between the magnetic rotor 11 and the valve needle 30, while also connecting the magnetic rotor 11 to the inner wall of the central hole 124 of the guide shaft 12, thereby improving the stability of the overall structural connection. Furthermore, the fact that the magnetic rotor 11 is molded within the central hole 124 can, to some extent, compensate for any gaps that may exist between the valve needle 30 and the central hole 124 due to machining precision issues, thus ensuring the stability of the valve needle 30 in the radial direction and preventing potential shaking during use.

[0069] In this embodiment, a limiting platform 1241 is formed in the central hole 124 to limit the position of one end of the valve needle 30 inserted into the central hole 124. At the same time, it cooperates with the magnetic rotor 11 formed in the annular groove 32 to achieve better fixation of the axial position of the valve needle 30. Moreover, the limiting platform 1241 can also serve as a positioning reference for the valve needle 30 to be installed into the central hole 124 during the pre-assembly of the guide shaft 12 and the valve needle 30.

[0070] It is important to note that, in order to ensure the coaxiality of the valve needle 30 and the guide shaft 12 during pre-assembly, a transition fit structure is generally formed between the outer wall of the valve needle 30 and the central hole 124 to achieve a more compact installation structure and ensure the stability of the guide shaft 12 and the valve needle 30 when they are placed in the injection mold of the magnetic rotor 11.

[0071] As attached Figure 2 As shown, in this embodiment, the magnetic rotor 11 has a Z-shaped cross section between the guide shaft 12 and the valve needle 30, which increases the bonding area between the components and makes the overall strength better.

[0072] As one embodiment of this utility model, see the appendix. Figure 4 A third plane 311 is formed on the outer wall of the first annular protrusion 31, and a fourth plane that fits with the third plane 311 is formed by injection molding on the magnetic rotor 11.

[0073] In this embodiment, a third plane 311 is provided on the first annular protrusion 31. The function of the third plane 311 is similar to that of the first plane 1221. In actual use, a fourth plane that cooperates with the third plane 311 is formed on the magnetic rotor 11. Similarly, the torsional strength between the magnetic rotor 11 and the valve needle 30 can be improved by the cooperation of the two planes.

[0074] As one embodiment of this utility model, see the appendix. Figure 1The valve body assembly 20 further includes a nut seat 24, which is fixed inside the valve body 21 and spaced apart from the valve seat 22. A mounting through hole is formed on the nut seat 24, through which the valve needle 30 passes. An external thread 33 is formed on the outer side wall of the valve needle 30, and an internal thread 241 that mates with the external thread 33 is formed on the inner wall of the mounting through hole. The valve needle 30 is threadedly connected to the mounting through hole.

[0075] In this embodiment, the valve needle 30 has a built-in threaded structure and is directly threaded to the nut seat 24. The rotation driven by the magnetic rotor 11 causes the valve needle 30 to achieve axial displacement under the action of the threaded engagement, thereby achieving control of the opening degree.

[0076] Compared with the structure in related technologies where the valve needle 30 is connected to the nut seat 24 via a lead screw sleeve, the structure of the valve stem in this embodiment is greatly simplified, which also reduces the assembly process, improves production efficiency, and helps to ensure the positional accuracy of the valve needle 30 and the nut seat 24.

[0077] In this application, the valve needle has a tapered mating section at one end near the valve port, and there is a gap between the tapered mating section and the valve port. In this embodiment, the valve needle always maintains a gap with the valve port during adjustment; that is, the expansion valve in this application is used as a normally open valve.

[0078] In this embodiment, the expansion valve is manufactured by first processing a guide shaft and a valve needle. The guide shaft is injection molded from plastic (the outer spiral guide is simultaneously injection molded during the molding process). The guide shaft is a plastic part, and the valve needle (usually a metal part) is also processed. After the guide shaft and valve needle are manufactured, they are pre-assembled (the valve needle is inserted into the center hole of the guide shaft). Then, the guide shaft and valve needle are placed into the injection mold, and the magnetic rotor is then injection molded. During the injection molding process, the magnetic rotor forms a mating structure that matches the connection structure of the guide shaft and valve needle. The injection molding process of the magnetic rotor fixes the guide shaft, valve needle, and magnetic rotor into a whole in one step. This greatly simplifies the assembly process, improves product accuracy, and reduces production costs.

[0079] The above are merely specific embodiments of this utility model, but the scope of protection of this utility model is not limited thereto. Those skilled in the art should understand that this utility model includes, but is not limited to, the contents described in the accompanying drawings and the specific embodiments above. Any modifications that do not depart from the functional and structural principles of this utility model will be included within the scope of the claims.

Claims

1. An electronic expansion valve, comprising a rotor assembly (10), a valve body assembly (20), and a valve needle (30), wherein the rotor assembly (10) comprises a magnetic rotor (11) and a guide shaft (12), the valve body assembly (20) comprises a valve body (21) and a valve port seat (22), one end of the valve port seat (22) is disposed within the valve body (21) and forms a valve port (23), the magnetic rotor (11) and the guide shaft (12) drive a first end of the valve needle (30) to approach or move away from the valve port (23) to adjust the opening degree of the expansion valve, characterized in that, A spiral guide rail (123) is formed on the outer side wall of the guide rail shaft (12). The spiral guide rail (123) is used to cooperate with the slip ring (13). The magnetic rotor (11) is injection molded on the outside of the guide rail shaft (12) and the valve needle (30), and the guide rail shaft (12) and the valve needle (30) are fixedly connected as a whole. The magnetic rotor (11), the guide rail shaft (12) and the valve needle (30) are coaxial and move synchronously.

2. The expansion valve according to claim 1, characterized by, The guide shaft (12) includes a shaft body (121) and a shaft seat (122). The outer wall of the shaft body (121) forms the spiral guide rail (123). The magnetic rotor (11) includes a cylindrical body (111) and a connecting part (112). The cylindrical body (111) is sleeved on the shaft body (121). The connecting part (112) is disposed at the end of the cylindrical body (111) and on the outside of the shaft seat (122). A first mating part is formed on the outer wall of the shaft seat (122). A second mating part is formed on the connecting part (112) to mate with the first mating part. The first mating part and the second mating part cooperate with each other to restrict the relative circumferential rotation of the guide shaft (12) and the magnetic rotor (11).

3. The expansion valve according to claim 2, wherein The first mating part includes a first plane (1221) disposed on the outer wall of the bearing part (122), and the second mating part includes a second plane disposed on the inner wall of the connecting part (112). The first plane (1221) and the second plane are fitted together.

4. The expansion valve according to claim 3, wherein The first mating part includes a mating groove (1222) disposed on the outer wall of the bearing portion (122), and the second mating part includes a mating protrusion disposed on the connecting portion (112). The mating protrusion is inserted into the mating groove (1222), and the first plane (1221) and the mating groove (1222) are arranged circumferentially around the axis of the bearing portion (122).

5. The expansion valve according to any one of claims 1 to 4, characterized in that, A central hole (124) is formed in the center of the guide shaft (12). The second end of the valve needle (30) is inserted into the central hole (124). A first annular protrusion (31) is formed on the outer wall of the valve needle (30). A second annular protrusion (126) is formed on the bottom surface of the guide shaft (12). The first annular protrusion (31) is located inside the second annular protrusion (126) and forms a gap with the bottom surface of the guide shaft (12). An injection molding space is formed between the first annular protrusion (31), the second annular protrusion (126), and the bottom surface of the guide shaft (12). A part of the magnetic rotor (11) is formed in the injection molding space to achieve a fixed connection between the magnetic rotor (11), the guide shaft (12), and the valve needle (30).

6. The expansion valve according to claim 5, wherein An annular groove (32) is formed on the outer wall of the valve needle (30). A part of the annular groove (32) is placed inside the central hole (124), and another part is placed outside the central hole (124). The first annular protrusion (31) is disposed on the side of the annular groove (32) outside the central hole (124). The annular groove (32) is connected to the injection space. A part of the magnetic rotor (11) is formed in the annular groove (32).

7. The expansion valve according to claim 6, wherein A third plane (311) is formed on the outer wall of the first annular protrusion (31), and a fourth plane that fits with the third plane (311) is formed by injection molding on the magnetic rotor (11).

8. The expansion valve according to any one of claims 1 to 4, characterized by The valve body assembly (20) further includes a nut seat (24), which is fixed inside the valve body (21) and spaced apart from the valve port seat (22). A mounting through hole is formed on the nut seat (24), through which the valve needle (30) passes. An external thread (33) is formed on the outer side wall of the valve needle (30), and an internal thread (241) that mates with the external thread (33) is formed on the inner wall of the mounting through hole. The valve needle (30) is threadedly connected to the mounting through hole.

9. The expansion valve according to any one of claims 1 to 4, characterized by The guide shaft (12) is made of plastic and is injection molded.

10. The expansion valve according to any one of claims 1 to 4, characterized by The first end of the valve needle (30) has a conical mating section (34), and there is a gap between the conical mating section (34) and the valve port (23).

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