Electronic expansion valve

Abstract

The utility model provides an electronic expansion valve which comprises a valve body structure, a driving assembly, a valve sleeve, a valve needle and an elastic assembly. The driving assembly is movably arranged in the valve body structure and is provided with a mounting hole; the valve sleeve is fixedly connected with the driving assembly, the end, away from the valve port, of the valve sleeve is provided with a first limiting face, the valve sleeve is tubular, and the axial length of the valve sleeve is larger than the outer diameter of the valve sleeve. The valve needle penetrates through the valve sleeve, the hardness of the valve sleeve is lower than that of the valve needle, the valve needle is provided with a second limiting surface, and the second limiting surface and the first limiting surface are in limiting fit in the axial direction of the valve needle; the elastic assembly is arranged in the mounting hole, and the two ends of the elastic assembly abut against the bottom wall of the mounting hole and the end face of the valve needle correspondingly. The driving assembly drives the valve needle to move axially, and the valve needle opens and closes the valve port and adjusts the opening degree of the valve port. Through the scheme, the friction force between the valve sleeve and the valve needle during contact is reduced, the valve opening resistance is reduced, and the valve opening performance is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of electronic expansion valves, in particular to an electronic expansion valve. Background Art

[0002] In the electronic expansion valve, the driving component drives the valve needle to move axially, and the valve opening or opening or adjusting the opening of the valve opening is driven by the valve needle. A valve sleeve connected to the driving component is also provided in the electronic expansion valve, and the axial relative position of the valve needle and the driving component is limited by the valve sleeve. During the valve switching process, the axial relative position of the valve needle and the valve sleeve changes. When the valve is fully closed, the lower end face of the tail of the valve needle and the upper end face of the valve sleeve are separated. When the valve steps from the fully closed position to the valve opening pulse point position, the lower end face of the tail of the valve needle and the valve sleeve change from the separated state to the contact state. Since the valve needle and the valve sleeve need to rotate relative to each other, the friction between the valve needle and the valve sleeve is very large at this time, resulting in the maximum resistance of the valve at this time, affecting the valve opening performance. There are some solutions in the prior art to reduce the friction between the valve sleeve and the valve needle, but they are still not ideal. Therefore, research and improvement are still needed to solve the problem of large friction between the valve sleeve and the valve needle in the electronic expansion valve. Utility Model Content

[0003] The utility model provides an electronic expansion valve to solve the problem of large friction between a valve sleeve and a valve needle in the electronic expansion valve in the prior art.

[0004] In order to solve the above problems, the utility model provides an electronic expansion valve, comprising: a valve body structure, the valve body structure has a valve port; a drive assembly, movably in the valve body structure, the drive assembly has a mounting hole; a valve sleeve, fixedly connected to the drive assembly, the end of the valve sleeve away from the valve port has a first limit surface, the valve sleeve is tubular, and the axial length of the valve sleeve is greater than the outer diameter of the valve sleeve; a valve needle, which is arranged through the valve sleeve, the hardness of the valve sleeve is lower than that of the valve needle, and the valve needle has a second limit surface, and the second limit surface and the first limit surface cooperate in the axial limit of the valve needle; an elastic assembly, which is arranged in the mounting hole, and the two ends of the elastic assembly are respectively abutted against the bottom wall of the mounting hole and the end face of the valve needle; wherein the drive assembly drives the valve needle to move axially, and the valve needle opens and closes the valve port and adjusts the opening of the valve port.

[0005] Furthermore, the valve sleeve is made of plastic or metal.

[0006] Furthermore, the valve sleeve is made of PPS, nylon, copper alloy or aluminum alloy.

[0007] Furthermore, the valve sleeve is located in the mounting hole, the inner wall of the mounting hole has a step surface, and the first limiting surface abuts against the step surface.

[0008] Furthermore, the step surface is annular, the difference between the outer radius and the inner radius of the step surface is L1, and the thickness of the valve sleeve is L2, wherein 1 / 3≤L1 / L2≤2 / 3.

[0009] Furthermore, the diameter of the mounting hole is less than 5 mm, the axial dimension of the valve sleeve is 1.5 mm to 4 mm, and the thickness of the valve sleeve is 0.3 mm to 1.1 mm.

[0010] Furthermore, the outer wall of the valve sleeve and the inner wall of the mounting hole are transitionally matched, and the inner wall of the valve sleeve and the outer wall of the valve needle are clearance matched.

[0011] Furthermore, the valve sleeve is located in the mounting hole, and one end of the drive assembly facing the valve port has an annular thinned flange, and the thinned flange is fixedly connected to the valve sleeve.

[0012] Furthermore, the driving component is a screw rod, and the elastic component includes a preload spring, and two ends of the preload spring are respectively in contact with the bottom wall of the mounting hole and the valve needle.

[0013] Alternatively, the driving assembly includes a screw and a valve needle sleeve, wherein one end of the screw near the valve port is rotatably connected to the valve needle sleeve, the valve needle sleeve has a mounting hole, the valve sleeve and the valve needle sleeve are fixedly connected, and the elastic assembly includes a pre-tensioning spring, wherein both ends of the pre-tensioning spring respectively abut against the bottom wall of the mounting hole and the valve needle.

[0014] Furthermore, the valve body structure includes a valve tube and a valve seat connected to each other, and the valve seat has a valve port; the electronic expansion valve also includes a nut seat, the nut seat and the valve seat are fixedly connected, the valve tube covers the nut seat, and the drive assembly and the nut seat are threadedly matched.

[0015] The technical scheme of the utility model is applied to provide an electronic expansion valve, including a valve body structure, a drive assembly, a valve sleeve, a valve needle and an elastic assembly, wherein the valve body structure has a valve port; the drive assembly is movably disposed in the valve body structure, and the drive assembly has a mounting hole; the valve sleeve and the drive assembly are fixedly connected, and the end of the valve sleeve away from the valve port has a first limit surface; the valve needle is arranged through the valve sleeve, the hardness of the valve sleeve is lower than that of the valve needle, the valve needle has a second limit surface, and the second limit surface and the first limit surface cooperate in the axial limit of the valve needle; the elastic assembly is arranged in the mounting hole, and the two ends of the elastic assembly are respectively in contact with the bottom wall of the mounting hole and the end face of the valve needle; wherein the drive assembly drives the valve needle to move axially, and the valve needle opens and closes the valve port and adjusts the opening of the valve port. In this scheme, the material of the valve sleeve is set to be a material with a lower hardness than that of the valve needle. Compared with the existing valve sleeve and the valve needle being made of the same metal material, the friction between the valve sleeve and the valve needle is small when in contact, thereby reducing the friction between the valve sleeve and the valve needle, reducing the valve opening resistance, and improving the valve opening performance. Furthermore, the valve sleeve is in a circular tubular shape, and the axial length of the valve sleeve is greater than the outer diameter of the valve sleeve. Thus, the valve sleeve is in a slender structure, and has a good guiding effect on the valve needle. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The drawings constituting part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation on the present invention. In the drawings:

[0017] Figure 1 A schematic diagram of the structure of an electronic expansion valve provided in an embodiment of the utility model is shown;

[0018] Figure 2 Shows Figure 1 A partial enlarged view of .

[0019] The above drawings include the following reference numerals:

[0020] 10. Valve body structure; 11. Valve port; 12. Valve tube; 13. Valve seat; 20. Drive assembly; 21. Mounting hole; 22. Step surface; 23. Thinning flange; 30. Valve sleeve; 31. First limit surface; 40. Valve needle; 41. Second limit surface; 50. Elastic assembly; 51. Preload spring; 52. Fitting part; 60. Nut seat. DETAILED DESCRIPTION

[0021] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means a limitation on the utility model and its application or use. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the utility model.

[0022] like Figure 1 to Figure 2 As shown, an embodiment of the utility model provides an electronic expansion valve, comprising: a valve body structure 10, the valve body structure 10 having a valve port 11; a drive assembly 20, movably disposed in the valve body structure 10, the drive assembly 20 having a mounting hole 21; a valve sleeve 30, fixedly connected to the drive assembly 20, the end of the valve sleeve 30 away from the valve port 11 having a first limit surface 31; a valve needle 40, disposed through the valve sleeve 30, the hardness of the valve sleeve 30 being lower than that of the valve needle 40, the valve needle 40 having a second limit surface 41, the second limit surface 41 and the first limit surface 31 being matched in the axial limit of the valve needle 40; an elastic assembly 50, disposed in the mounting hole 21, the two ends of the elastic assembly 50 respectively abutting against the bottom wall of the mounting hole 21 and the end face of the valve needle 40; wherein the drive assembly 20 drives the valve needle 40 to move axially, the valve needle 40 opens and closes the valve port 11 and adjusts the opening of the valve port 11.

[0023] In this solution, the material of the valve sleeve 30 is set to be a material with a lower hardness than the valve needle 40. Compared with the existing valve sleeve 30 and valve needle 40 made of the same metal material, the friction between the valve sleeve 30 and the valve needle 40 is small when in contact, thereby reducing the friction between the valve sleeve 30 and the valve needle 40, reducing the valve opening resistance, and improving the valve opening performance. In addition, the valve sleeve 30 is in a circular tube shape, and the axial length of the valve sleeve 30 is greater than the outer diameter of the valve sleeve 30. In this way, the valve sleeve 30 is a slender structure, which has a good guiding effect on the valve needle 40.

[0024] The valve sleeve 30 may be made of plastic or metal with a low friction coefficient to reduce the friction between the valve sleeve 30 and the valve needle 40 .

[0025] Specifically, the material of the valve sleeve 30 is PPS or nylon or copper alloy, all of which have good wear resistance and low friction. When the material of the valve sleeve 30 is PPS, it can be integrally injection molded, with low manufacturing cost and self-lubricating characteristics. Of course, the material of the valve sleeve 30 can also be aluminum alloy, etc. Among them, the drive assembly 20 can be made of stainless steel and other materials.

[0026] like Figure 2 As shown, the valve sleeve 30 is located in the mounting hole 21, and the inner wall of the mounting hole 21 has a step surface 22, and the first limiting surface 31 abuts against the step surface 22. In this way, the valve sleeve 30 is axially limited by the cooperation of the first limiting surface 31 and the step surface 22, and the limiting effect is good. Compared with the use of interference fit, damage to the valve sleeve 30 is avoided.

[0027] Specifically, the step surface 22 is annular, the difference between the outer radius and the inner radius of the step surface 22 is L1, the thickness of the valve sleeve 30 is L2, and 1 / 3≤L1 / L2≤2 / 3. The above-mentioned size range is set to ensure that the step surface 22 effectively limits the valve sleeve 30 in the axial direction, and does not affect the contact between the valve sleeve 30 and the valve needle 40, that is, does not affect the cooperation between the first limiting surface 31 and the second limiting surface 41.

[0028] In this solution, the diameter of the mounting hole 21 is less than 5 mm, the axial dimension of the valve sleeve 30 is 1.5 mm to 4 mm, for example, 2.5 mm, and the thickness of the valve sleeve 30 is 0.3 mm to 1.1 mm. In this way, the valve sleeve 30, the valve needle 40 and the elastic component 50 can be installed in a compact space.

[0029] Specifically, the outer wall of the valve sleeve 30 and the inner wall of the mounting hole 21 are transitionally matched, which facilitates the installation of the two. The inner wall of the valve sleeve 30 and the outer wall of the valve needle 40 are clearance-matched, which avoids or reduces the friction between the inner wall of the valve sleeve 30 and the outer wall of the valve needle 40, thereby reducing the resistance of the switch valve.

[0030] like Figure 2As shown, the valve sleeve 30 is located in the mounting hole 21, and the end of the drive assembly 20 facing the valve port 11 has an annular thinning flange 23, and the thinning flange 23 and the end of the valve sleeve 30 facing the valve port 11 are fixedly connected, for example, by welding or riveting. The axial position of the valve sleeve 30 is limited by riveting, which is convenient for assembly and reliable for limiting, and avoids the valve sleeve 30 and the drive assembly 20 from being separated. The end of the drive assembly 20 facing the valve port 11 is thinned to facilitate deformation riveting.

[0031] like Figure 1 and Figure 2 As shown, in this embodiment, the driving assembly 20 is a screw rod, and the elastic assembly 50 includes a preload spring 51, and the two ends of the preload spring 51 are respectively in contact with the bottom wall of the mounting hole 21 and the valve needle 40. Further, the elastic assembly 50 includes a preload spring 51 and a fitting 52, and the two ends of the preload spring 51 are respectively in contact with the bottom wall of the mounting hole 21 and the fitting 52, and the fitting 52 is in contact with the end surface of the valve needle 40. In this way, the preload spring 51 and the fitting 52 can apply an axial preload force to the valve needle 40.

[0032] In an embodiment not shown in the figure, the drive assembly 20 includes a screw and a valve needle sleeve. One end of the screw near the valve port 11 is rotatably connected to the valve needle sleeve. The valve needle sleeve has a mounting hole. The valve sleeve 30 and the valve needle sleeve are fixedly connected. The elastic assembly 50 includes a pre-loaded spring 51. Both ends of the pre-loaded spring 51 are respectively in contact with the bottom wall of the mounting hole 21 and the valve needle 40.

[0033] Furthermore, the elastic component 50 includes a preload spring 51 and a fitting 52, and the bearing, the fitting 52, the preload spring 51 and the end surface of the valve needle 40 are in contact with each other in sequence. With this solution, the friction between the valve needle 40 and the valve port 11 at the valve opening pulse point can be reduced. In addition, the preload spring 51 and the fitting 52 can apply an axial preload force to the valve needle 40.

[0034] like Figure 1 As shown, the valve body structure 10 includes a valve tube 12 and a valve seat 13 connected to each other, and the valve seat 13 has a valve port 11; the electronic expansion valve also includes a nut seat 60, the nut seat 60 and the valve seat 13 are fixedly connected, the valve tube 12 covers the nut seat 60, and the drive assembly 20 and the nut seat 60 are threadedly matched. The valve tube 12 and the valve seat 13 are fixedly connected by welding or other means. The drive assembly 20 rotates relative to the nut seat 60, thereby achieving axial movement and driving the valve needle 40 to move.

[0035] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may be subject to various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

[0036] 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, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0037] Unless otherwise specifically stated, the relative arrangement, numerical expressions and numerical values ​​of the parts and steps set forth in these embodiments do not limit the scope of the utility model. At the same time, it should be understood that, for ease of description, the sizes of the various parts shown in the accompanying drawings are not drawn according to the actual proportional relationship. The technology, method and equipment known to those of ordinary skill in the relevant art may not be discussed in detail, but in appropriate cases, the technology, method and equipment should be considered as a part of the specification. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters represent similar items in the following drawings, and therefore, once a certain item is defined in an accompanying drawing, it does not need to be further discussed in subsequent drawings.

[0038] In the description of the present utility model, it needs to be understood that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "lateral, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the drawings, and are only for the convenience of describing the present utility model 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, and therefore cannot be understood as limiting the scope of protection of the present utility model; the directional words "inside and outside" refer to the inside and outside relative to the contours of each component itself.

[0039] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. 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 figure. For example, if the device in the accompanying 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.

[0040] 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. If not otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of the utility model.

Claims

1. An electronic expansion valve, characterized in that: include: A valve body structure (10), wherein the valve body structure (10) has a valve port (11); A drive assembly (20) is movably disposed in the valve body structure (10), wherein the drive assembly (20) has a mounting hole (21); A valve sleeve (30) is fixedly connected to the driving assembly (20), the end of the valve sleeve (30) facing away from the valve port (11) has a first limit surface (31), the valve sleeve (30) is in a circular tube shape, and the axial length of the valve sleeve (30) is greater than the outer diameter of the valve sleeve (30); A valve needle (40) is arranged through the valve sleeve (30), the hardness of the valve sleeve (30) is lower than that of the valve needle (40), and the valve needle (40) has a second limiting surface (41), and the second limiting surface (41) and the first limiting surface (31) are matched in the axial limiting of the valve needle (40); An elastic component (50) is arranged in the mounting hole (21), and two ends of the elastic component (50) are respectively in contact with end surfaces of the drive component (20) and the valve needle (40); The driving assembly (20) drives the valve needle (40) to move axially, and the valve needle (40) opens and closes the valve port (11) and adjusts the opening degree of the valve port (11).

2. The electronic expansion valve according to claim 1, characterized in that: The valve sleeve (30) is made of plastic or metal.

3. The electronic expansion valve according to claim 2, characterized in that: The material of the valve sleeve (30) is PPS, nylon, copper alloy or aluminum alloy.

4. The electronic expansion valve according to claim 1, characterized in that: The valve sleeve (30) is located in the mounting hole (21); the inner wall of the mounting hole (21) has a step surface (22); and the first limiting surface (31) abuts against the step surface (22).

5. The electronic expansion valve according to claim 4, characterized in that: The step surface (22) is annular, the difference between the outer radius and the inner radius of the step surface (22) is L1, the thickness of the valve sleeve (30) is L2, wherein: 1 / 3≤L1 / L2≤2 / 3.

6. The electronic expansion valve according to claim 4, characterized in that: The diameter of the mounting hole (21) is less than 5 mm, the axial dimension of the valve sleeve (30) is 1.5 mm to 4 mm, and the thickness of the valve sleeve (30) is 0.3 mm to 1.1 mm.

7. The electronic expansion valve according to claim 4, characterized in that: The outer wall of the valve sleeve (30) and the inner wall of the mounting hole (21) are transitionally matched, and the inner wall of the valve sleeve (30) and the outer wall of the valve needle (40) are clearance matched.

8. The electronic expansion valve according to claim 1, characterized in that: The valve sleeve (30) is located in the mounting hole (21); one end of the drive assembly (20) facing the valve port (11) has an annular thinned flange (23); the thinned flange (23) and the valve sleeve (30) are fixedly connected.

9. The electronic expansion valve according to claim 1, characterized in that: The driving component (20) is a screw rod, and the elastic component (50) includes a preload spring (51). Two ends of the preload spring (51) are respectively in contact with the bottom wall of the mounting hole (21) and the valve needle (40).

10. The electronic expansion valve according to claim 1, characterized in that: The driving assembly (20) includes a screw and a valve needle sleeve. One end of the screw near the valve port (11) is rotatably connected to the valve needle sleeve. The valve needle sleeve has the mounting hole (21). The valve sleeve (30) and the valve needle sleeve are fixedly connected. The elastic assembly (50) includes a preload spring (51). Both ends of the preload spring (51) are respectively in contact with the bottom wall of the mounting hole (21) and the valve needle (40).

11. The electronic expansion valve according to claim 1, characterized in that: The valve body structure (10) comprises a valve tube (12) and a valve seat (13) which are connected to each other, and the valve seat (13) has the valve port (11); the electronic expansion valve also comprises a nut seat (60), the nut seat (60) and the valve seat (13) are fixedly connected, the valve tube (12) covers the nut seat (60), and the drive assembly (20) and the nut seat (60) are threadedly matched.

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