Electronic expansion valve

Abstract

Provided in the present application is an electronic expansion valve, comprising: a valve seat portion, wherein a valve port is provided in the valve seat portion, and a limiting face is provided at the end of the valve seat portion away from the valve port; a nut structure, wherein an end face of the nut structure abuts against the limiting face so as to limit the axial direction of the nut structure; a connecting plate, which is in limiting fit with the nut structure and is connected to the valve seat portion; and a valve element assembly, which is connected to the nut structure in a threaded manner and is configured to regulate the flow of a medium flowing through the valve port. In the solution, axial positioning of the nut structure is implemented by means of the fit between the end face of the nut structure and the limiting face of the valve seat portion, and by using such a method, it is not necessary to axially position the portion of the valve seat portion that extends into the nut structure, and an inner hole of the nut structure, and the machining and assembling accuracy can be easily ensured; in addition, the contact area between the end face of the nut structure and the limiting face of the valve seat portion is large, such that the nut structure is not prone to being crushed, and further limiting and assembling of the nut structure are then implemented by means of fitting with the connecting plate.

Description

Electronic expansion valve

[0001] This application claims priority to patent application number 202322494115.8, filed with the State Intellectual Property Office of China on September 13, 2023, and entitled “Electronic Expansion Valve”;

[0002] This application claims priority to a patent application filed with the State Intellectual Property Office of China on September 13, 2023, with application number 202322499875.8 and title “Electronic Expansion Valve.” Technical Field

[0003] The present application relates to the technical field of electronic expansion valves, and in particular to an electronic expansion valve. Background Art

[0004] The electronic expansion valve is provided with a nut structure and a valve core assembly. The nut structure and the valve core assembly are threaded together, and the valve core assembly moves axially when it rotates, thereby opening and closing the valve port and adjusting the flow rate. The nut structure needs to be precisely positioned axially during assembly. In the prior art, a portion of the valve seat portion is inserted into the inner hole of the nut structure, and the inserted portion abuts against the step surface in the inner hole. This assembly method has high requirements on the height dimension of the portion of the valve seat portion that penetrates the inner hole, and the dimension is prone to deviation. When the dimension is out of tolerance, it affects the assembly accuracy. In addition, the step surface area in the nut structure is small, and there is a risk of it being crushed, which affects the yield rate of the product. Therefore, it is necessary to optimize the assembly of the nut structure in the electronic expansion valve to improve the assembly accuracy and yield rate.

[0005] Application Contents

[0006] The present application provides an electronic expansion valve to solve the problems of low assembly precision and easy crushing of the nut structure in the electronic expansion valve in the prior art, thereby improving the assembly precision and the yield rate.

[0007] In order to solve the above problems, the present application provides an electronic expansion valve, including: a valve seat portion, wherein the valve seat portion has a valve port, and the valve seat portion has a limiting surface at one end away from the valve port; a nut structure, wherein the end face of the nut structure abuts against the limiting surface to limit the axial position of the nut structure; a connecting plate, which is limitedly matched with the nut structure, and the connecting plate is connected to the valve seat portion; a valve core assembly, wherein the valve core assembly is threadedly connected to the nut structure, and the valve core assembly is used to adjust the flow rate of the medium flowing through the valve port.

[0008] Furthermore, the nut structure includes a nut body and a limiting ring that are connected to each other, the end face of the limiting ring abuts against the limiting surface, and the thickness of the limiting ring is 1.8 mm to 4.3 mm.

[0009] Furthermore, the nut structure has an inner hole, the opening of the inner hole faces the valve port, the valve seat portion has an annular boss protruding from the limiting surface, the annular boss penetrates into the inner hole, the annular boss and the inner hole are transitionally fitted, and the length of the inner hole is greater than the length of the annular boss.

[0010] Furthermore, the outer wall of the nut structure has a mating surface, and the end surface of the connecting plate abuts against the mating surface to limit the connection plate in the thickness direction.

[0011] Furthermore, the connecting plate is annular, and is sleeved on the nut structure. The connecting plate and the nut structure are matched in radial clearance, and the connecting plate and the nut structure are matched in circumferential limiting.

[0012] Furthermore, the valve seat portion has an annular groove, at least a portion of the connecting plate is located in the annular groove, the connecting plate and the bottom wall of the annular groove are clearance-fitted, and the connecting plate and the side wall of the annular groove are welded.

[0013] Furthermore, the valve seat portion includes a valve seat body and a guide sleeve, the guide sleeve is fixed in the valve seat body, the guide sleeve has the limiting surface, and the valve core assembly passes through the guide sleeve to be guided by the guide sleeve.

[0014] Furthermore, the inner wall of the valve seat body has a positioning ring, the outer wall of the guide sleeve has an annular step, and the end face of the positioning ring abuts against the end face of the annular step to limit the relative axial position of the guide sleeve and the valve seat body.

[0015] Furthermore, the valve seat body has an assembly hole and a valve cavity, the guide sleeve includes a large diameter section and a small diameter section connected to each other, the outer diameter of the large diameter section is larger than the outer diameter of the small diameter section, the large diameter section is fixed in the assembly hole, and the small diameter section is located in the valve cavity.

[0016] Furthermore, the valve core assembly includes a screw and a valve head, the screw and the nut structure are threadedly connected, and the screw drives the valve head to move to open and close the valve port; the thread specification in the nut structure is M4*0.7.

[0017] The technical solution of the present application provides an electronic expansion valve, comprising: a valve seat portion having a valve port therein and a limiting surface at one end of the valve seat portion away from the valve port; a nut structure, an end face of the nut structure abutting the limiting surface to limit the nut structure in axial direction; a connecting plate, engaging with the nut structure to limit position and connected to the valve seat portion; and a valve core assembly, threadedly connected to the nut structure, for regulating the flow of a medium passing through the valve port. In this solution, the axial positioning of the nut structure is achieved by the engagement of the end face of the nut structure with the limiting surface of the valve seat portion. This method eliminates the need for axially positioning the portion of the valve seat portion extending into the nut structure and the inner hole of the nut structure, facilitating machining and assembly accuracy. Furthermore, the contact area between the end face of the nut structure and the limiting surface of the valve seat portion is large, making it less likely to damage the nut structure. Further positioning and assembly of the nut structure are achieved by engagement of the connecting plate. This solution solves the problem of low assembly accuracy and easy damage of the nut structure, thereby improving assembly accuracy and yield. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The drawings that constitute part of this application are used to provide a further understanding of this application. The illustrative embodiments of this application and their descriptions are used to explain this application and do not constitute an improper limitation on this application. In the drawings:

[0019] FIG1 shows a schematic structural diagram of an electronic expansion valve provided in an embodiment of the present application;

[0020] FIG2 shows a partial enlarged view of FIG1 ;

[0021] FIG3 shows a schematic structural diagram of the guide sleeve in FIG1 .

[0022] Among them, the above-mentioned drawings include the following figure marks: 10. Valve seat body; 11. Annular groove; 12. Positioning ring; 13. Assembly hole; 14. Valve cavity; 20. Guide sleeve; 21. Limiting surface; 22. Annular boss; 23. Annular step; 24. Large diameter section; 25. Small diameter section; 26. Guide hole; 30. Nut structure; 31. Nut body; 32. Limiting ring; 33. Inner hole; 34. Mating surface; 40. Connecting plate; 50. Valve core assembly; 51. Screw; 52. Valve head. DETAILED DESCRIPTION

[0023] The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is in no way intended to limit the present application and its application or use. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0024] As shown in Figures 1 to 3, an embodiment of the present application provides an electronic expansion valve, including: a valve seat portion, a valve port being provided in the valve seat portion, and a limiting surface 21 being provided at an end of the valve seat portion away from the valve port; a nut structure 30, the end face of the nut structure 30 abutting against the limiting surface 21 to limit the axial direction of the nut structure 30; a connecting plate 40, which is limitedly matched with the nut structure 30, and the connecting plate 40 is connected to the valve seat portion; a valve core assembly 50, the valve core assembly 50 is threadedly connected to the nut structure 30, and the valve core assembly 50 is used to adjust the flow rate of the medium flowing through the valve port.

[0025] In this solution, the axial positioning of the nut structure 30 is achieved through the cooperation between the end face of the nut structure 30 and the limiting surface 21 of the valve seat. This method eliminates the need for axial positioning of the portion of the valve seat extending into the nut structure 30 and the inner hole of the nut structure 30, making it easier to ensure machining and assembly accuracy. In addition, the contact area between the end face of the nut structure 30 and the limiting surface 21 of the valve seat is large, making it less likely to damage the nut structure 30. Further limiting and assembly of the nut structure 30 is achieved through the cooperation between the connecting plate 40 and the valve seat. This solution solves the problem of low assembly precision and easy damage of the nut structure 30, and improves assembly accuracy and yield rate.

[0026] The nut structure 30 includes a nut body 31 and a limiting ring 32 that are interconnected. The end face of the limiting ring 32 abuts the limiting surface 21, and the thickness of the limiting ring 32 is 1.8 mm to 4.3 mm. This makes the limiting ring 32 thicker than the structure in the prior art, improving the limiting ring 32's ability to withstand pressure and thus preventing it from being crushed during assembly. Furthermore, the outer diameter of the limiting ring 32 is larger than the outer diameter of the nut body 31, and the end face area of ​​the limiting ring 32 is relatively large, resulting in a large contact area with the limiting surface 21 of the valve seat portion, reducing stress concentration and preventing the nut structure 30 from being crushed after assembly.

[0027] In this embodiment, the nut structure 30 has an inner hole 33, the opening of the inner hole 33 faces the valve port, the valve seat portion has an annular boss 22 protruding from the limiting surface 21, the annular boss 22 penetrates the inner hole 33, the annular boss 22 and the inner hole 33 are transitionally matched, and the length of the inner hole 33 is greater than the length of the annular boss 22. Through the cooperation of the annular boss 22 and the inner hole 33, the nut structure 30 can be limited in the radial direction. The use of the transition fit method avoids the nut structure 30 from being crushed when the annular boss 22 is pressed in. In addition, the length of the inner hole 33 is greater than the length of the annular boss 22, so that the end face of the annular boss 22 will not contact the bottom wall or the stepped inner wall of the inner hole 33, thereby avoiding the annular boss 22 from crushing the nut structure 30.

[0028] As shown in Figures 1 and 2, the outer wall of the nut structure 30 has a mating surface 34, and the end surface of the connecting plate 40 abuts against the mating surface 34 to limit the position in the thickness direction of the connecting plate 40. In this way, through the cooperation between the connecting plate 40 and the nut structure 30, the nut structure 30 is limited in both axial directions.

[0029] The connecting plate 40 is annular and is sleeved onto the nut structure 30. The connecting plate 40 and the nut structure 30 are matched with radial clearance and circumferential position. The circumferential position of the connecting plate 40 and the nut structure 30 restricts the circumferential position of the nut structure 30 and prevents rotation of the nut structure 30. The radial clearance between the connecting plate 40 and the nut structure 30 allows for adjustment during assembly of the nut structure 30, preventing it from becoming stuck, ensuring that the nut structure 30 is properly assembled, and maintaining its coaxiality.

[0030] Specifically, the circumferential position-limiting fit between the connecting plate 40 and the nut structure 30 is achieved by: a lug is provided on the outer wall of the nut structure 30, and a groove is provided on the inner wall of the connecting plate 40. The lug snaps into the groove, thereby achieving the circumferential position-limiting fit between the nut structure 30 and the connecting plate 40. The lug and groove form a transition fit, and multiple pairs of lugs and grooves can be provided to improve connection reliability.

[0031] In this embodiment, the valve seat portion has an annular groove 11, with at least a portion of the connecting plate 40 positioned within the annular groove 11. The connecting plate 40 and the bottom wall of the annular groove 11 are clearance-fitted, and the connecting plate 40 and the side walls of the annular groove 11 are welded. The clearance fit between the connecting plate 40 and the bottom wall of the annular groove 11 prevents axial over-positioning. The connecting plate 40 and the side walls of the annular groove 11 are welded for a reliable connection, specifically by laser welding. A portion of the connecting plate 40 protrudes from the annular groove 11, facilitating laser welding and focusing alignment.

[0032] In this solution, the valve seat portion can be configured as either an integral or split structure. As shown in Figures 1 and 2 , the valve seat portion comprises a valve seat body 10 and a guide sleeve 20. The guide sleeve 20 is secured within the valve seat body 10 and has a limiting surface 21. The valve core assembly 50 passes through the guide sleeve 20 for guidance. Providing a split valve seat portion can reduce manufacturing complexity.

[0033] The valve seat body 10 , the guide sleeve 20 and the connecting plate 40 are all made of metal materials, and the nut structure 30 is made of plastic material.

[0034] Specifically, the inner wall of the valve seat body 10 has a positioning ring 12, and the outer wall of the guide sleeve 20 has an annular step 23. The end face of the positioning ring 12 and the end face of the annular step 23 abut against each other to limit the relative axial position of the guide sleeve 20 and the valve seat body 10. This achieves precise axial positioning of the guide sleeve 20 and the valve seat body 10. The inner wall of the valve seat body 10 and the outer wall of the guide sleeve 20 are welded to achieve a reliable connection between the two. The welding process can be laser welding or furnace welding. After the annular step 23 of the guide sleeve 20 and the positioning ring 12 of the valve seat body 10 are assembled, they are connected by welding, specifically by laser welding. A portion of the annular step 23 protrudes from the positioning ring 12 to facilitate focusing of the laser welding.

[0035] As shown in Figures 2 and 3, the valve seat body 10 has an assembly hole 13 and a valve cavity 14. The guide sleeve 20 includes a large-diameter section 24 and a small-diameter section 25 that are interconnected. The outer diameter of the large-diameter section 24 is larger than that of the small-diameter section 25. The large-diameter section 24 is fixed in the assembly hole 13, and the small-diameter section 25 is located in the valve cavity 14. The large-diameter section 24 and the small-diameter section 25 jointly guide the valve core assembly 50, improving the guidance effect of the valve core assembly 50, ensuring the coaxiality of the valve core assembly 50, and reducing the vibration of the valve core assembly 50. In addition, the outer diameter of the small-diameter section 25 is smaller than that of the large-diameter section 24. This increases the Cv value of the valve cavity 14 and improves the fluidity of the fluid in the valve cavity 14.

[0036] Specifically, the outer surface of the thin-diameter section 25 is tapered, with the larger end of the tapered surface connected to the larger-diameter section 24 and the smaller end of the tapered surface facing the valve port. This arrangement not only ensures the structural strength of the guide sleeve 20, but also minimizes the size of the thin-diameter section 25, thereby increasing the Cv value of the valve cavity 14.

[0037] The guide sleeve 20 has a guide hole 26 that mates with the valve core assembly 50. The inner diameter of the guide hole 26 ranges from 13 mm to 15 mm, the wall thickness of the thin-diameter section 25 ranges from 0.5 mm to 1.5 mm, and the wall thickness of the thick-diameter section 24 ranges from 1.5 mm to 2.5 mm. This dimensional range ensures that the guide sleeve 20 has sufficient strength and a relatively small wall thickness, ensuring effective guidance of the valve head 52 while reducing resistance to fluid flow.

[0038] As shown in Figure 1, the valve core assembly 50 includes a screw 51 and a valve head 52. The screw 51 is threadedly connected to the nut structure 30, and the screw 51 drives the valve head 52 to open and close the valve port. When the electronic expansion valve is fully opened, the stroke of the valve head 52 ranges from 2.7 mm to 4.3 mm, meaning that the stroke of the valve head 52 is a fixed value between 2.7 mm and 4.3 mm. The stroke of the valve head 52 can also be understood as the distance between the valve head 52 and the valve port after the valve port is opened. This increases the distance between the valve head 52 and the valve port when the valve port is fully opened, reducing the obstruction of the valve head 52 to the fluid and improving the Cv value. The thread size of the screw 51 has been changed from the conventional M3*0.5 to M4*0.7. This increases the stroke of the screw 51 for the same number of turns, thereby increasing the distance between the valve head 52 and the valve port and improving the Cv value.

[0039] Existing electronic expansion valves open and close the valve port through the reciprocating motion of the valve head. Poor guidance of the valve head can cause deflection, which not only affects the valve's on / off performance but also easily produces jitter noise when impacted by fluid. Therefore, the valve head must have good coaxiality. To improve the guidance of the valve head in electronic expansion valves, some electronic expansion valves are equipped with a guide sleeve to guide the valve head, but this still suffers from poor guidance.

[0040] In the present application, the guide sleeve 20 has a guide hole 26, and the valve core assembly 50 includes a valve head 52. The valve head 52 is movably disposed within the guide hole 26 to open and close the valve port. When the electronic expansion valve is fully closed, a portion of the valve head 52 is located outside the guide hole 26, and the length of the portion of the valve head 52 located within the guide hole 26 is no less than 40% of the length of the valve head 52. For example, the length of the portion of the valve head 52 located within the guide hole 26 is 50% of the length of the valve head 52.

[0041] In this embodiment, when the electronic expansion valve is fully closed, the length of the valve head 52 located within the guide hole 26 of the guide sleeve 20 is the shortest, and the length of the valve head 52 extending out of the guide hole 26 is the longest. The length of the portion of the valve head 52 located within the guide hole 26 is limited to no less than 40% of the length of the valve head 52. This ensures that the guide sleeve 20 has a good guiding effect on the valve head 52 throughout the movement of the valve head 52, improves the coaxiality of the valve head 52, and reduces the jitter of the valve head 52, thereby ensuring the on-off valve performance of the electronic expansion valve and reducing the jitter noise generated when the valve head 52 is impacted by the fluid.

[0042] In this embodiment, when the electronic expansion valve is fully closed, the length of the valve head 52 within the guide hole 26 is L1, and the length of the valve head 52 is L2. The relationship between the two dimensions is 0.4 < L1 / L2 < 0.7. Limiting the relationship between the two dimensions to this range facilitates part processing and assembly while ensuring effective guidance of the valve head 52. For example, L1 / L2 = 0.5.

[0043] In this embodiment, the valve seat body 10 has an assembly hole 13. The guide sleeve 20 is interference-fitted with the inner wall of the assembly hole 13 and then welded. This ensures the coaxiality of the guide sleeve 20 and the assembly hole 13 and achieves a secure connection. Specifically, the guide sleeve 20 and the inner wall of the assembly hole 13 can be laser welded or furnace welded.

[0044] The above are merely preferred embodiments of the present application and are not intended to limit the present application. Those skilled in the art will readily appreciate that various modifications and variations are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present application shall be included within the scope of protection of the present application.

[0045] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components and / or combinations thereof.

[0046] Unless otherwise specifically stated, the relative arrangement of the parts and steps, numerical expressions and numerical values ​​set forth in these embodiments do not limit the scope of the present application. At the same time, it should be understood that, for ease of description, the sizes of the various parts shown in the drawings are not drawn according to actual proportional relationships. The techniques, methods and equipment known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, the techniques, methods and equipment should be considered as part of the authorization specification. In all examples shown and discussed here, any specific values ​​should be interpreted as being merely exemplary and not as limitations. Therefore, other examples of the exemplary embodiments may have different values. It should be noted that similar numbers and letters represent similar items in the following figures, and therefore, once an item is defined in one figure, it does not need to be further discussed in subsequent figures.

[0047] In the description of this application, it should be understood that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "horizontal, vertical, vertical, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the device or element referred to must have a specific direction or be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the scope of protection of this application; the directional words "inside and outside" refer to the inside and outside relative to the outline of each component itself.

[0048] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used herein to describe the spatial positional relationship of a device or feature to other devices or features as shown in the figures. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figures. For example, if the device in the drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0049] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of this application.

Claims

1. An electronic expansion valve, characterized in that: include: A valve seat portion, wherein the valve seat portion has a valve port therein, and an end of the valve seat portion away from the valve port has a limiting surface (21); A nut structure (30), wherein an end surface of the nut structure (30) abuts against the limiting surface (21) to limit the axial direction of the nut structure (30); A connecting plate (40) is limitedly matched with the nut structure (30), and the connecting plate (40) is connected to the valve seat portion; A valve core assembly (50), the valve core assembly (50) and the nut structure (30) are threadedly connected, and the valve core assembly (50) is used to adjust the flow rate of the medium flowing through the valve port.

2. The electronic expansion valve according to claim 1, characterized in that: The nut structure (30) comprises a nut body (31) and a limiting ring (32) which are connected to each other, the end face of the limiting ring (32) abuts against the limiting surface (21), and the thickness of the limiting ring (32) is 1.8 mm to 4.3 mm.

3. The electronic expansion valve according to claim 1, characterized in that: The nut structure (30) has an inner hole (33), the opening of the inner hole (33) faces the valve port, the valve seat portion has an annular boss (22) protruding from the limiting surface (21), the annular boss (22) penetrates into the inner hole (33), the annular boss (22) and the inner hole (33) are transitionally matched, and the length of the inner hole (33) is greater than the length of the annular boss (22).

4. The electronic expansion valve according to claim 1, characterized in that: The outer wall of the nut structure (30) has a matching surface (34), and the end surface of the connecting plate (40) abuts against the matching surface (34) to limit the connection plate (40) in a thickness direction.

5. The electronic expansion valve according to claim 4, characterized in that: The connecting plate (40) is annular and is sleeved on the nut structure (30). The connecting plate (40) and the nut structure (30) are matched in radial clearance and in circumferential limiting manner.

6. The electronic expansion valve according to claim 4, characterized in that: The valve seat portion has an annular groove (11), at least a portion of the connecting plate (40) is located in the annular groove (11), the connecting plate (40) and the bottom wall of the annular groove (11) are clearance-matched, and the connecting plate (40) and the side wall of the annular groove (11) are welded.

7. The electronic expansion valve according to claim 1, characterized in that: The valve seat portion comprises a valve seat body (10) and a guide sleeve (20), wherein the guide sleeve (20) is fixed inside the valve seat body (10), the guide sleeve (20) has the limiting surface (21), and the valve core assembly (50) passes through the guide sleeve (20) to be guided by the guide sleeve (20).

8. The electronic expansion valve according to claim 7, characterized in that: The inner wall of the valve seat body (10) has a positioning ring (12), the outer wall of the guide sleeve (20) has an annular step (23), and the end surface of the positioning ring (12) abuts against the end surface of the annular step (23) to limit the relative axial position of the guide sleeve (20) and the valve seat body (10).

9. The electronic expansion valve according to claim 7, characterized in that: The valve seat body (10) has an assembly hole (13) and a valve cavity (14); the guide sleeve (20) comprises a large diameter section (24) and a small diameter section (25) which are connected to each other; the outer diameter of the large diameter section (24) is larger than the outer diameter of the small diameter section (25); the large diameter section (24) is fixed in the assembly hole (13); and the small diameter section (25) is located in the valve cavity (14).

10. The electronic expansion valve according to claim 1, characterized in that: The valve core assembly (50) comprises a screw (51) and a valve head (52); the screw (51) and the nut structure (30) are threadedly connected; the screw (51) drives the valve head (52) to move to open and close the valve port; the thread specification in the nut structure (30) is M4*0.

7.

11. The electronic expansion valve according to claim 9, characterized in that: The outer surface of the thin-diameter section (25) is a conical surface, the end of the conical surface with a larger diameter is connected to the thick-diameter section (24), and the end of the conical surface with a smaller diameter faces the valve port.

12. The electronic expansion valve according to claim 9, characterized in that: The guide sleeve (20) has a guide hole (26) that cooperates with the valve core assembly (50), the inner diameter of the guide hole (26) is 13 mm to 15 mm, the wall thickness of the thin diameter section (25) is 0.5 mm to 1.5 mm, and the wall thickness of the thick diameter section (24) is 1.5 mm to 2.5 mm.

13. The electronic expansion valve according to claim 7, characterized in that: The guide sleeve (20) has a guide hole (26), and the valve core assembly (50) includes a valve head (52), and the valve head (52) is movably arranged in the guide hole (26) to open and close the valve port; Wherein, when the electronic expansion valve is fully closed, a portion of the valve head (52) is located outside the guide hole (26), and the length of the portion of the valve head (52) located inside the guide hole (26) is not less than 40% of the length of the valve head (52).

14. The electronic expansion valve according to claim 13, characterized in that: When the electronic expansion valve is fully closed, the length of the valve head (52) in the guide hole (26) is L1, the length of the valve head (52) is L2, and 0.4<L1 / L2<0.

7.

15. The electronic expansion valve according to claim 7, characterized in that: The valve seat body (10) has an assembly hole (13), and the guide sleeve (20) and the inner wall of the assembly hole (13) are interference-fitted and welded.

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