Electronic expansion valve

Abstract

This invention provides an electronic expansion valve, comprising: a nut assembly including a nut and a connecting plate sleeved on the nut, the connecting plate and the nut having a radial clearance fit; a valve seat, the outer wall of the connecting plate being fixedly connected to the valve seat, the connecting plate and the valve seat having an axial clearance fit in the nut; and a guide sleeve fixedly disposed within the cavity of the valve seat, the guide sleeve being inserted into the nut, the guide sleeve and the nut abutting axially and having a radial interference fit. This design ensures the coaxiality of the guide sleeve and the nut by limiting their relative movement in the axial and radial directions. Furthermore, given a fixed coaxiality between the nut and the guide sleeve, sufficient adjustment clearances are provided between the connecting plate and the nut, and between the connecting plate and the valve seat, preventing over-positioning of the connecting plate during installation from affecting the coaxiality between the nut and the guide sleeve, thus improving the coaxiality of the nut assembly and ensuring the performance of the electronic expansion valve.

Description

Technical Field

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

[0002] In existing electronic expansion valves, the installation accuracy between the nut assembly, valve seat, and guide sleeve cannot be guaranteed during installation, leading to a decrease in the coaxiality among these components. Furthermore, existing electronic expansion valves are prone to over-positioning or inaccurate positioning of the nut or connecting plate during installation, affecting the overall installation accuracy. Summary of the Invention

[0003] This invention provides an electronic expansion valve to improve the installation accuracy of electronic expansion valves in the prior art.

[0004] To address the aforementioned problems, the present invention provides an electronic expansion valve, comprising: a nut assembly, the nut assembly including a nut and a connecting plate sleeved on the nut, the connecting plate and the nut being in a radial clearance fit; a valve seat, the outer wall of the connecting plate being fixedly connected to the valve seat, the connecting plate and the valve seat being in an axial clearance fit with the nut; and a guide sleeve, fixedly disposed within the cavity of the valve seat, the guide sleeve being inserted into the nut, the guide sleeve and the nut abutting in the axial direction and having an interference fit in the radial direction.

[0005] Furthermore, the nut has a positioning hole with a stop surface inside the positioning hole, one end of the guide sleeve passes through the positioning hole, the end face of the guide sleeve abuts against the stop surface, and the outer wall of the guide sleeve and the inner wall of the positioning hole are interference-fitted; or the guide sleeve has a positioning hole with a stop surface inside the positioning hole, one end of the nut passes through the positioning hole, the end face of the nut abuts against the stop surface, and the outer wall of the nut and the inner wall of the positioning hole are interference-fitted.

[0006] Furthermore, the electronic expansion valve also includes a positioning boss disposed in the valve seat, the positioning boss and the guide sleeve being inserted at the end away from the nut, the positioning boss and the guide sleeve abutting in the axial direction and having an interference fit in the radial direction.

[0007] Furthermore, the positioning boss and the valve seat are an integral structure; or, the electronic expansion valve includes a valve port component, which includes a positioning boss and a body connected to the positioning boss. The valve port component also has a valve port that passes through the body and the positioning boss. The body and the valve seat are fixedly connected. The positioning boss passes through the end of the guide sleeve away from the nut. The positioning boss and the guide sleeve are interference-fitted. The guide sleeve and the body abut against each other.

[0008] Furthermore, the body includes a first shaft segment, a second shaft segment, and a third shaft segment connected in sequence, with the outer diameters of the first shaft segment, the second shaft segment, and the third shaft segment decreasing sequentially. The first shaft segment is connected to a positioning boss. The valve seat has a first mating hole and a second mating hole that are interconnected, with the diameter of the first mating hole being larger than the diameter of the second mating hole. The first shaft segment passes through the first mating hole, the second shaft segment passes through the second mating hole, and the third shaft segment is located outside the valve seat.

[0009] Furthermore, the nut includes a nut body and a first limiting structure disposed on the nut body, and the connecting plate includes a connecting ring and a second limiting structure disposed on the connecting ring. The connecting ring is sleeved on the nut body, and the connecting ring and the nut body are in clearance fit. The first limiting structure and the second limiting structure are in radial clearance fit on the connecting ring, and the first limiting structure and the second limiting structure are in circumferential interference fit on the connecting ring.

[0010] Furthermore, the first limiting structure is a limiting boss set on the outer wall of the nut body, and the second limiting structure is a limiting groove set on the inner wall of the connecting plate. The limiting boss has two first limiting surfaces and a first mating surface located between the two first limiting surfaces, and the limiting groove has two second limiting surfaces and a second mating surface located between the two second limiting surfaces. The first mating surfaces and the second mating surfaces are in clearance fit, and the two first limiting surfaces and the two second limiting surfaces are in a one-to-one limiting fit.

[0011] Furthermore, the nut body includes a nut segment, a transition segment, a connecting segment, and a limiting plate connected in sequence. The outer diameter of the connecting segment is larger than the outer diameter of the nut segment, and the outer diameter of the limiting plate is larger than the outer diameter of the connecting segment. The connecting plate is detachably sleeved on the connecting segment, and the connecting plate and the limiting plate abut against each other. The first limiting structure is located on the outer wall of the connecting segment.

[0012] Furthermore, the inner wall of the valve seat has a first stepped surface parallel to the nut axis and a second stepped surface perpendicular to the nut axis. The first stepped surface and the second stepped surface form a stepped structure. The outer wall of the connecting plate is connected to the first stepped surface, and the connecting plate and the second stepped surface are in clearance fit.

[0013] Furthermore, one part of the connecting plate is located inside the stepped structure, and the other part of the connecting plate is located outside the stepped structure. The connecting plate and the valve seat are welded together.

[0014] Furthermore, the electronic expansion valve also includes a valve cover and a rotor assembly. The valve cover and valve seat are connected. The rotor assembly is disposed inside the valve cover. The rotor assembly includes a magnetic rotor and a rotating connector disposed inside the magnetic rotor. The rotating connector includes a rotor connecting plate and a guide rod that are connected to each other. The rotor connecting plate and the magnetic rotor are fixedly connected. The guide rod extends along the axial direction of the nut. The nut assembly also includes a stop ring that is rotatably disposed on the nut. The side wall of the guide rod and the stop ring are in a limiting fit.

[0015] Furthermore, the rotating connecting parts are an integral structure, or the rotor connecting plate and the guide rod are two separate structures; the guide rod and the inner wall of the magnetic rotor are clearance-fitted, or the guide rod and the inner wall of the magnetic rotor are attached.

[0016] Furthermore, the rotor assembly also includes a limiting member, the rotor connecting plate has a press-fit groove, and the limiting member is disposed in the press-fit groove; a portion of the nut is located inside the magnetic rotor, and the electronic expansion valve also includes a valve needle assembly, the screw of the valve needle assembly and the limiting member are welded together, and the screw and the nut are threadedly connected.

[0017] The present invention provides an electronic expansion valve, comprising: a nut assembly, the nut assembly including a nut and a connecting plate sleeved on the nut, the connecting plate and the nut having a radial clearance fit; a valve seat, the outer wall of the connecting plate being fixedly connected to the valve seat, the connecting plate and the valve seat having an axial clearance fit in the nut; and a guide sleeve, fixedly disposed within the cavity of the valve seat, the guide sleeve and the nut being inserted into each other, the guide sleeve and the nut abutting axially and having a radial interference fit. This solution ensures the coaxiality of the guide sleeve and the nut by limiting their relative movement in the axial and radial directions. Furthermore, given a fixed coaxiality between the nut and the guide sleeve, sufficient adjustment clearances are provided between the connecting plate and the nut, and between the connecting plate and the valve seat, preventing over-positioning of the connecting plate during installation from affecting the coaxiality between the nut and the guide sleeve, thus improving the coaxiality of the nut assembly. Specifically, the connecting plate and the nut are in a radial clearance fit. During the installation of the nut assembly, when the guide sleeve and the nut abut, there is a clearance between the connecting plate and the valve seat in the axial direction of the nut. This avoids the situation in related technologies where, when the guide sleeve and the nut abut, the connecting plate and the valve seat also abut in the axial direction of the nut, leading to over-positioning of the nut. It also avoids the situation where the connecting plate and the valve seat abut in the axial direction of the nut first, but the guide sleeve and the nut do not abut, resulting in inaccurate positioning of the nut assembly. This improves the installation accuracy of the nut assembly in the electronic expansion valve and ensures the performance of the electronic expansion valve. Attached Figure Description

[0018] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0019] Figure 1 A schematic diagram of the structure of the electronic expansion valve provided in an embodiment of the present invention is shown;

[0020] Figure 2 It shows Figure 1 A schematic diagram of the nut assembly in an electronic expansion valve;

[0021] Figure 3 It shows Figure 2 A schematic diagram of the nut structure in the nut assembly;

[0022] Figure 4 It shows Figure 3 A cross-sectional view of the nut;

[0023] Figure 5 It shows Figure 1 An enlarged view of position B in the electronic expansion valve;

[0024] Figure 6 It shows Figure 3 A top view of the nut;

[0025] Figure 7 It shows Figure 2 A schematic diagram of the connecting plate in the nut assembly;

[0026] Figure 8 It shows Figure 1 An enlarged view of position A in the electronic expansion valve;

[0027] Figure 9 It shows Figure 1 A schematic diagram of the rotor assembly in an electronic expansion valve.

[0028] The above figures include the following reference numerals:

[0029] 10. Nut assembly; 11. Nut; 111. Locating hole; 112. Stop surface; 113. Nut body; 1131. Nut segment; 1132. Transition segment; 1133. Connecting segment; 1134. Limiting plate; 114. First limiting structure; 1141. First limiting surface; 1142. First mating surface; 12. Connecting plate; 121. Connecting ring; 122. Second limiting structure; 1221. Second limiting surface; 1222. Second mating surface;

[0030] 20. Valve seat; 21. First stepped surface; 22. Second stepped surface;

[0031] 30. Guide sleeve;

[0032] 40. Valve port component; 41. Positioning boss; 42. Body; 421. First shaft section; 422. Second shaft section; 423. Third shaft section;

[0033] 50. Valve cover;

[0034] 60. Rotor assembly; 61. Magnetic rotor; 62. Rotary connecting component; 621. Rotor connecting plate; 622. Guide rod; 623. Press-fit groove; 63. Limiting component;

[0035] 70. Valve needle assembly. Detailed Implementation

[0036] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0037] like Figures 1 to 9 As shown, an embodiment of the present invention provides an electronic expansion valve, comprising: a nut assembly 10, the nut assembly 10 including a nut 11 and a connecting plate 12 sleeved on the nut 11, the connecting plate 12 and the nut 11 being in a radial clearance fit; a valve seat 20, the outer wall of the connecting plate 12 being fixedly connected to the valve seat 20, the connecting plate 12 and the valve seat 20 being in an axial clearance fit with the nut 11; and a guide sleeve 30, fixedly disposed in the cavity of the valve seat 20, the guide sleeve 30 and the nut 11 being inserted into each other, the guide sleeve 30 and the nut 11 abutting in the axial direction and having an interference fit in the radial direction.

[0038] In this embodiment, by restricting the relative movement between the guide sleeve 30 and the nut 11 in the axial and radial directions, the coaxiality of the guide sleeve 30 and the nut 11 is ensured. Furthermore, given that the coaxiality of the nut 11 and the guide sleeve 30 is determined, sufficient adjustment clearance is provided between the connecting plate 12 and the nut 11, as well as between the connecting plate 12 and the valve seat 20, to prevent the connecting plate 12 from being over-positioned during installation, which would affect the coaxiality between the nut 11 and the guide sleeve 30, thereby improving the coaxiality of the nut assembly 10. Specifically, the connecting plate 12 and the nut 11 are in a radial clearance fit. During the installation of the nut assembly 10, when the guide sleeve 30 and the nut 11 abut, the connecting plate 12 and the valve seat 20 have a clearance in the axial direction of the nut 11. This avoids the situation in related technologies where, when the guide sleeve and the nut abut, the connecting plate and the valve seat also abut in the axial direction of the nut, resulting in over-positioning of the nut. It also avoids the situation where the connecting plate and the valve seat abut in the axial direction of the nut first, but the guide sleeve and the nut do not abut, resulting in inaccurate positioning of the nut assembly. This improves the installation accuracy of the nut assembly in the electronic expansion valve and ensures the performance of the electronic expansion valve.

[0039] Specifically, this configuration also minimizes the size of the nut assembly 10 and valve seat 20 in the electronic expansion valve, thereby miniaturizing the electronic expansion valve as much as possible.

[0040] like Figures 1 to 4As shown, the nut 11 has a positioning hole 111, and a stop surface 112 is provided inside the positioning hole 111. One end of the guide sleeve 30 passes through the positioning hole 111, and the end face of the guide sleeve 30 abuts against the stop surface 112. The outer wall of the guide sleeve 30 and the inner wall of the positioning hole 111 are interference-fitted. Alternatively, the guide sleeve 30 has a positioning hole 111, and a stop surface 112 is provided inside the positioning hole 111. One end of the nut 11 passes through the positioning hole 111, and the end face of the nut 11 abuts against the stop surface 112. The outer wall of the nut 11 and the inner wall of the positioning hole 111 are interference-fitted. This configuration facilitates the machining of the nut 11 and the guide sleeve 30, improving the production efficiency of the electronic expansion valve. Specifically, this embodiment is the case where the nut 11 has a positioning hole 111, and one end of the guide sleeve 30 passes through the positioning hole 111.

[0041] like Figure 1 and Figure 5 As shown, the electronic expansion valve also includes a positioning boss 41 disposed within the valve seat 20. The positioning boss 41 and the guide sleeve 30 are inserted at the end away from the nut 11. The positioning boss 41 and the guide sleeve 30 abut in the axial direction and are interference-fitted in the radial direction. This arrangement, through the limiting fit between the positioning boss 41 and the guide sleeve 30, ensures the coaxiality between the positioning boss 41 and the guide sleeve 30, thereby ensuring the coaxiality between the valve seat 20, the guide sleeve 30, and the nut assembly 10, and guaranteeing the performance of the electronic expansion valve.

[0042] Specifically, the positioning boss 41 and the valve seat 20 are an integral structure; or, the electronic expansion valve includes a valve port 40, which includes a positioning boss 41 and a body 42 connected to the positioning boss 41. The valve port 40 also has a valve port that passes through the body 42 and the positioning boss 41. The body 42 and the valve seat 20 are fixedly connected. The positioning boss 41 passes through the end of the guide sleeve 30 away from the nut 11. The positioning boss 41 and the guide sleeve 30 are interference-fitted. The guide sleeve 30 and the body 42 abut against each other.

[0043] In this embodiment, the positioning boss 41 and the valve seat 20 are separate structures. The valve port component 40 is used to position and install the guide sleeve 30, ensuring the coaxiality of the guide sleeve 30 and the valve seat 20. Specifically, the axis of the valve seat 20 is set through the center of the valve port. Through the above arrangement, the coaxiality of the nut assembly 10 and the valve port is ensured, thus ensuring the reliability of the electronic expansion valve.

[0044] like Figure 5As shown, the body 42 includes a first shaft segment 421, a second shaft segment 422, and a third shaft segment 423 connected in sequence. The outer diameters of the first shaft segment 421, the second shaft segment 422, and the third shaft segment 423 decrease sequentially. The first shaft segment 421 is connected to the positioning boss 41. The valve seat 20 has a first mating hole and a second mating hole that are interconnected. The diameter of the first mating hole is larger than the diameter of the second mating hole. The first shaft segment 421 passes through the first mating hole, the second shaft segment 422 passes through the second mating hole, and the third shaft segment 423 is located outside the valve seat 20. This arrangement ensures the reliability of the connection between the body 42 and the valve seat 20, ensures the coaxiality of the body 42 and the valve seat 20, and thus ensures the coaxiality of the guide sleeve 30 and the valve seat 20.

[0045] like Figure 6 and Figure 7 As shown, the nut 11 includes a nut body 113 and a first limiting structure 114 disposed on the nut body 113. The connecting plate 12 includes a connecting ring 121 and a second limiting structure 122 disposed on the connecting ring 121. The connecting ring 121 is sleeved on the nut body 113, and the connecting ring 121 and the nut body 113 are in clearance fit. The first limiting structure 114 and the second limiting structure 122 are in radial clearance fit on the connecting ring 121, and the first limiting structure 114 and the second limiting structure 122 are in circumferential interference fit on the connecting ring 121. This design allows the connecting plate 12 on the nut 11 to move radially but not circumferentially. This avoids the situation in related technologies where, during the installation of the nut assembly into the valve seat 20, the connecting plate 12 and valve seat 20 are also tightly fitted, causing the nut 11 to be over-positioned radially, compromising the coaxiality between the nut assembly 10 and the valve seat 20. This improves the coaxiality of the nut assembly 10 and the valve seat 20, reduces the machining accuracy and cost of the nut assembly 10, lowers the assembly difficulty of the nut assembly 10, and increases the production efficiency of the nut assembly 10. Furthermore, the limiting fit between the connecting plate 12 and the nut 11 is achieved through the limiting fit between the first limiting structure 114 and the second limiting structure 122. The first limiting structure 114 is directly mounted on the nut 11, and the second limiting structure 122 is directly mounted on the connecting plate 12. This facilitates machining while reducing the overall size of the first limiting structure 114 and the second limiting structure 122, ensuring the miniaturization of the nut assembly 10.

[0046] Specifically, the first limiting structure 114 is a limiting boss provided on the outer wall of the nut body 113, and the second limiting structure 122 is a limiting groove provided on the inner wall of the connecting plate 12. The limiting boss has two first limiting surfaces 1141 and a first mating surface 1142 located between the two first limiting surfaces 1141. The limiting groove has two second limiting surfaces 1221 and a second mating surface 1222 located between the two second limiting surfaces 1221. The first mating surface 1142 and the second mating surface 1222 are in clearance fit, and the two first limiting surfaces 1141 and the two second limiting surfaces 1221 are in a one-to-one limiting fit.

[0047] In this embodiment, the limiting fit between the first limiting structure 114 and the second limiting structure 122 is mainly designed as a limiting fit between a limiting protrusion and a limiting groove. This design is simple, easy to manufacture, and provides a reliable fit. Furthermore, the clearance fit between the first mating surface 1142 and the second mating surface 1222 allows the connecting plate 12 to move slightly radially along the nut body 113. The one-to-one limiting fit between the two first limiting surfaces 1141 and the two second limiting surfaces 1221 restricts the rotation of the connecting plate 12 along the circumferential direction of the nut body 113, preventing over-positioning of the connecting plate 12. Specifically, the two first limiting surfaces 1141 and the two second limiting surfaces 1221 are fitted with an interference fit.

[0048] like Figure 3 As shown, the nut body 113 includes a nut segment 1131, a transition segment 1132, a connecting segment 1133, and a limiting plate 1134 connected in sequence. The outer diameter of the connecting segment 1133 is larger than the outer diameter of the nut segment 1131, and the outer diameter of the limiting plate 1134 is larger than the outer diameter of the connecting segment 1133. The connecting plate 12 is detachably sleeved on the connecting segment 1133, and the connecting plate 12 and the limiting plate 1134 abut against each other. The first limiting structure 114 is located on the outer wall of the connecting segment 1133.

[0049] In this embodiment, the connecting plate 12 and the nut body 113 are detachably connected. By separating the connecting plate 12 and the nut body 113, the need for a connecting plate during insert injection molding of the nut assembly in related technologies is avoided, improving the production efficiency of the nut assembly. Simultaneously, it avoids the situation where the nut body 113 with the connecting plate 12 cannot be reused, allowing for better reuse of the nut body 113. Furthermore, this design avoids the situation in related technologies where the connection position between the connecting plate and the nut has excessive flash due to process reasons during insert injection molding of the nut assembly, leading to damage to the nut assembly, thus improving the structural strength of the nut assembly. Specifically, the first limiting structure 114 is connected to the connecting section 1133 and the limiting plate 1134.

[0050] like Figure 8As shown, the inner wall of the valve seat 20 has a first stepped surface 21 parallel to the axis of the nut 11 and a second stepped surface 22 perpendicular to the axis of the nut 11. The first stepped surface 21 and the second stepped surface 22 form a stepped structure. The outer wall of the connecting plate 12 is connected to the first stepped surface 21, and the connecting plate 12 and the second stepped surface 22 are in clearance fit. With this configuration, during the installation of the nut assembly 10, when the guide sleeve 30 and the stop surface 112 abut, there is a gap between the connecting plate 12 and the valve seat 20 in the axial direction of the nut. This avoids the situation in related technologies where, when the guide sleeve and the stop surface abut, the connecting plate and the valve body also abut in the axial direction of the nut, leading to over-positioning of the nut assembly. It also avoids the situation in related technologies where the connecting plate and the valve body abut in the axial direction of the nut first, but the guide sleeve and the stop surface do not abut, resulting in inaccurate positioning of the nut assembly. This improves the installation accuracy of the nut assembly 10 in the electronic expansion valve, ensures the reliability of the abutment between the guide sleeve 30 and the stop surface 112 for positioning the nut assembly 10, and thus improves the reliability of the electronic expansion valve. Furthermore, the connecting plate 12 is positioned and installed using a stepped structure, which facilitates processing and assembly positioning.

[0051] Specifically, a portion of the connecting plate 12 is located within the stepped structure, while another portion is located outside the stepped structure. The connecting plate 12 and the valve seat 20 are welded together. In this embodiment, the first stepped surface 21 and the end face of the valve seat 20 are connected. The welding position of the connecting plate 12 and the valve seat 20 is the contact line formed between the plane of the connecting plate 12 that does not abut against the first stepped surface 21 (i.e., the outer wall of the portion of the connecting plate 12 not located within the stepped structure) and the end face of the valve seat 20 that is connected to the first stepped surface 21. This arrangement provides a welding allowance for the welding of the connecting plate 12 and the valve seat 20, ensuring the reliability of the welding. Furthermore, the welded connection between the connecting plate 12 and the valve seat 20 is stable and reliable.

[0052] like Figure 1 and Figure 9 As shown, the electronic expansion valve also includes a valve cover 50 and a rotor assembly 60. The valve cover 50 is connected to the valve seat 20. The rotor assembly 60 is disposed inside the valve cover 50. The rotor assembly 60 includes a magnetic rotor 61 and a rotating connector 62 disposed inside the magnetic rotor 61. The rotating connector 62 includes a rotor connecting plate 621 and a guide rod 622 that are connected to each other. The rotor connecting plate 621 and the magnetic rotor 61 are fixedly connected. The guide rod 622 extends along the axial direction of the nut 11. The nut assembly 10 also includes a stop ring that is rotatably disposed on the nut 11. The side wall of the guide rod 622 and the stop ring are in a limiting fit.

[0053] In this embodiment, the rotor connecting plate 621 and the magnetic rotor 61 rotate synchronously under the drive of an external coil, which in turn drives the guide rod 622, which is fixedly connected to the rotor connecting plate 621, to rotate synchronously and move along the axial direction of the nut 11. During the movement of the guide rod 622, the guide rod 622 abuts against the stop ring, thereby driving the stop ring to move helically on the nut 11. This arrangement avoids the need for laser welding between the powder metallurgy rotor connecting plate and the guide plate in the prior art, which can easily lead to defects such as blackening and cracking after welding, thus ensuring the reliability of the rotor assembly 60.

[0054] like Figure 9 As shown, the rotating connector 62 is an integral structure, or the rotor connecting plate 621 and the guide rod 622 are two separate structures; the guide rod 622 and the inner wall of the magnetic rotor 61 are in clearance fit, or the guide rod 622 and the inner wall of the magnetic rotor 61 are in contact.

[0055] In this embodiment, the rotating connector 62 is an integral structure, which facilitates the processing of the rotating connector 62 and improves the production efficiency of the rotor assembly. Meanwhile, in this embodiment, there is no gap between the guide rod 622 and the magnetic rotor 61; therefore, the material of the guide rod 622 in this case is different from the material of the guide rod 622 when there is a gap between them.

[0056] Specifically, the rotor assembly 60 also includes a limiting member 63, and the rotor connecting plate 621 has a press-fit groove 623, within which the limiting member 63 is disposed. A portion of the nut 11 is located within the magnetic rotor 61. The electronic expansion valve also includes a valve needle assembly 70, where the screw of the valve needle assembly 70 is welded to the limiting member 63, and the screw and nut 11 are threaded together. This configuration securely connects the valve needle assembly 70 and the rotor connecting plate 621 together via the limiting member 63, reducing processing costs. Furthermore, by separating the various parts of the rotor assembly 60 and integrating the rotating connecting member 62 into a single structure, the prior art's powder metallurgy rotor assembly with insert mounting is susceptible to overheating, cracking, demagnetization, and other adverse phenomena when welded to the valve needle component, further ensuring the reliability of the rotor assembly 60.

[0057] Optionally, the limiting member 63 and the pressing groove 623 are interference-fitted or integrally injection molded, the pressing groove 623 is a rectangular groove, and the limiting member 63 and the valve needle assembly 70 are connected by screw welding.

[0058] Optionally, the rotor connecting plate 621 is made of Pps. Pps rotor connecting plates have better heat insulation performance and can prevent the magnetic rotor 61 from cracking when the screw of the limiting member 63 and the valve needle assembly 70 is welded.

[0059] Specifically, the installation process of the electronic expansion valve is as follows: First, the connected valve needle assembly 70 and nut assembly 10 are installed together with the valve seat 20, so that the inner side wall of the nut positioning hole 111 and the outer side wall of the guide sleeve 30 are in a limiting fit. Then, the connecting plate 12 is sleeved on the connecting section 1133, and a force is applied to the connecting plate 12 toward the limiting plate 1134, so that the connecting plate 12 and the limiting plate 1134 abut together, and the entire nut assembly 10 is moved into the cavity of the valve seat 20 until the stop surface 112 and one end of the guide sleeve 30 abut together. At this time, a step is formed between the connecting plate 12 and the side wall of the valve seat 20, and welding is performed at the connection position of the connecting plate 12 and the valve seat 20. Then, the completed rotor assembly 60 and valve needle assembly 70 are fixedly connected, and the completed rotor assembly 60, valve needle assembly 70 and nut assembly 10 are connected. Finally, the valve cover 50 and valve seat 20 are fixedly connected to complete the installation of the electronic expansion valve.

[0060] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. An electronic expansion valve, characterized in that, include: Nut assembly (10), the nut assembly (10) includes a nut (11) and a connecting plate (12) sleeved on the nut (11), the connecting plate (12) and the nut (11) being in a radial clearance fit; Valve seat (20), the outer side wall of the connecting plate (12) and the valve seat (20) are fixedly connected, and the connecting plate (12) and the valve seat (20) are axially clearance-fitted with the nut (11); A guide sleeve (30) is fixedly disposed in the cavity of the valve seat (20). The guide sleeve (30) and the nut (11) are inserted together. The guide sleeve (30) and the nut (11) abut in the axial direction and are interference-fitted in the radial direction.

2. The electronic expansion valve according to claim 1, characterized in that, The nut (11) has a positioning hole (111) and a stop surface (112) inside the positioning hole (111). One end of the guide sleeve (30) passes through the positioning hole (111), and the end face of the guide sleeve (30) abuts against the stop surface (112). The outer wall of the guide sleeve (30) and the inner wall of the positioning hole (111) are interference-fitted. Alternatively, the guide sleeve (30) may have a positioning hole (111) with a stop surface (112) inside the positioning hole (111). One end of the nut (11) is inserted into the positioning hole (111), and the end face of the nut (11) abuts against the stop surface (112). The outer wall of the nut (11) and the inner wall of the positioning hole (111) are interference-fitted.

3. The electronic expansion valve according to claim 1, characterized in that, The electronic expansion valve also includes a positioning boss (41) disposed in the valve seat (20), the positioning boss (41) and the guide sleeve (30) being inserted at one end away from the nut (11), the positioning boss (41) and the guide sleeve (30) abutting in the axial direction and having an interference fit in the radial direction.

4. The electronic expansion valve according to claim 3, characterized in that, The positioning boss (41) and the valve seat (20) are an integral structure; or, the electronic expansion valve includes a valve port (40), the valve port (40) includes the positioning boss (41) and a body (42) connected to the positioning boss (41), the valve port (40) also has a valve port that passes through the body (42) and the positioning boss (41), the body (42) and the valve seat (20) are fixedly connected, the positioning boss (41) passes through the end of the guide sleeve (30) away from the nut (11), the positioning boss (41) and the guide sleeve (30) are interference fit, and the guide sleeve (30) and the body (42) abut against each other.

5. The electronic expansion valve according to claim 4, characterized in that, The body (42) includes a first shaft segment (421), a second shaft segment (422), and a third shaft segment (423) connected in sequence. The outer diameters of the first shaft segment (421), the second shaft segment (422), and the third shaft segment (423) decrease sequentially. The first shaft segment (421) is connected to the positioning boss (41). The valve seat (20) has a first mating hole and a second mating hole that are interconnected. The diameter of the first mating hole is larger than the diameter of the second mating hole. The first shaft segment (421) passes through the first mating hole, the second shaft segment (422) passes through the second mating hole, and the third shaft segment (423) is located outside the valve seat (20).

6. The electronic expansion valve according to claim 1, characterized in that, The nut (11) includes a nut body (113) and a first limiting structure (114) disposed on the nut body (113). The connecting plate (12) includes a connecting ring (121) and a second limiting structure (122) disposed on the connecting ring (121). The connecting ring (121) is sleeved on the nut body (113). The connecting ring (121) and the nut body (113) are in clearance fit. The first limiting structure (114) and the second limiting structure (122) are in radial clearance fit on the connecting ring (121). The first limiting structure (114) and the second limiting structure (122) are in circumferential interference fit on the connecting ring (121).

7. The electronic expansion valve according to claim 6, characterized in that, The first limiting structure (114) is a limiting boss provided on the outer wall of the nut body (113), and the second limiting structure (122) is a limiting groove provided on the inner wall of the connecting plate (12). The limiting boss has two first limiting surfaces (1141) and a first mating surface (1142) located between the two first limiting surfaces (1141). The limiting groove has two second limiting surfaces (1221) and a second mating surface (1222) located between the two second limiting surfaces (1221). The first mating surface (1142) and the second mating surface (1222) are in clearance fit, and the two first limiting surfaces (1141) and the two second limiting surfaces (1221) are in a one-to-one limiting fit.

8. The electronic expansion valve according to claim 7, characterized in that, The nut body (113) includes a nut segment (1131), a transition segment (1132), a connecting segment (1133), and a limiting plate (1134) connected in sequence. The outer diameter of the connecting segment (1133) is larger than the outer diameter of the nut segment (1131), and the outer diameter of the limiting plate (1134) is larger than the outer diameter of the connecting segment (1133). The connecting plate (12) is detachably sleeved on the connecting segment (1133), and the connecting plate (12) and the limiting plate (1134) abut against each other. The first limiting structure (114) is located on the outer wall of the connecting segment (1133).

9. The electronic expansion valve according to claim 1, characterized in that, The inner wall of the valve seat (20) has a first stepped surface (21) parallel to the axis of the nut (11) and a second stepped surface (22) perpendicular to the axis of the nut (11). The first stepped surface (21) and the second stepped surface (22) form a stepped structure. The outer wall of the connecting plate (12) is connected to the first stepped surface (21), and the connecting plate (12) and the second stepped surface (22) are in clearance fit.

10. The electronic expansion valve according to claim 9, characterized in that, A portion of the connecting plate (12) is located inside the stepped structure, and another portion of the connecting plate (12) is located outside the stepped structure. The connecting plate (12) and the valve seat (20) are welded together.

11. The electronic expansion valve according to claim 10, characterized in that, The electronic expansion valve also includes a valve cover (50) and a rotor assembly (60). The valve cover (50) is connected to the valve seat (20). The rotor assembly (60) is disposed inside the valve cover (50). The rotor assembly (60) includes a magnetic rotor (61) and a rotating connector (62) disposed inside the magnetic rotor (61). The rotating connector (62) includes a rotor connecting plate (621) and a guide rod (622) connected to each other. The rotor connecting plate (621) and the magnetic rotor (61) are fixedly connected. The guide rod (622) extends along the axial direction of the nut (11). The nut assembly (10) also includes a stop ring rotatably disposed on the nut (11). The side wall of the guide rod (622) and the stop ring are in a limiting fit.

12. The electronic expansion valve according to claim 11, characterized in that, The rotating connector (62) is an integral structure, or the rotor connecting plate (621) and the guide rod (622) are two separate structures; the guide rod (622) and the inner wall of the magnetic rotor (61) are in clearance fit, or the guide rod (622) and the inner wall of the magnetic rotor (61) are in contact.

13. The electronic expansion valve according to claim 11, characterized in that, The rotor assembly (60) further includes a limiting member (63), the rotor connecting plate (621) has a press-fit groove (623), and the limiting member (63) is disposed in the press-fit groove (623); a portion of the nut (11) is located in the magnetic rotor (61), and the electronic expansion valve further includes a valve needle assembly (70), the screw of the valve needle assembly (70) is welded to the limiting member (63), and the screw and the nut (11) are threadedly connected.

Images