Valve needle assembly and electronic expansion valve

Abstract

The utility model provides a valve needle assembly and an electronic expansion valve, and relates to the technical field of valves. The valve needle assembly comprises a valve needle body, a lining and a sealing structure, the valve needle body comprises an adjusting part and a fixing part, the adjusting part is used for selectively blocking a valve port, one side of the fixing part is connected to the adjusting part in the axial direction of the adjusting part, and a fixing groove is formed in the other side of the fixing part; the lining is arranged outside the valve needle body in a sleeving mode, a limiting part is arranged at the end, away from the adjusting part, of the lining in the axial direction of the adjusting part, and the limiting part is configured to be capable of being bent in the radial direction of the adjusting part in the direction close to the fixing groove, so that the limiting part is arranged in the fixing groove; the sealing structure is arranged outside the valve needle body in a sleeving mode and arranged between the valve needle body and the lining. Heat cannot be generated by adopting a riveting mode, the risk of thermal deformation of the sealing structure is reduced, the sealing effect of the valve needle assembly is improved, and therefore the use reliability of the sealing structure is improved.

Description

Technical Field

[0001] The utility model generally relates to the technical field of valves, and more specifically, to a valve needle assembly and an electronic expansion valve. Background Art

[0002] The electronic expansion valve is applicable to the refrigeration and cold storage fields and has two characteristics of low internal leakage and flow regulation accuracy, and can replace the combination of a solenoid valve and a thermal expansion valve. At present, a seal is usually arranged on the outer periphery of the valve needle. The cooperation between the valve needle and the valve port can achieve the regulation of the flow rate, and the cooperation between the seal and the valve port can achieve low internal leakage.

[0003] The existing seal is press-fitted on the outer wall of the valve needle, and the two are pressed into the bushing as a whole. Then, the bushing and the tail of the valve needle are integrally formed by laser welding to form an integral valve needle assembly. Since the laser welding between the bushing and the valve needle will thermally affect the seal, the seal is deformed by heat, thereby affecting the sealing effect. Summary of the Utility Model

[0004] The utility model provides a valve needle assembly and an electronic expansion valve, which can reduce the deformation of the sealing structure and improve the use effect.

[0005] According to the first aspect of the utility model, a valve needle assembly is provided, which includes:

[0006] A valve needle body, including an adjusting part and a fixing part. The adjusting part is used for selectively blocking the valve port. Along the axial direction of the adjusting part, one side of the fixing part is connected to the adjusting part, and a fixing groove is arranged on the upper end surface of the other side of the fixing part;

[0007] A bushing, sleeved on the outside of the valve needle body. Along the axial direction of the adjusting part, a limiting part is arranged at one end of the bushing away from the adjusting part. The limiting part is configured to be bent along the radial direction of the adjusting part and towards the direction close to the fixing groove, so that the limiting part is arranged in the fixing groove;

[0008] A sealing structure, sleeved on the outside of the valve needle body and arranged between the valve needle body and the bushing.

[0009] In some embodiments, along the axial direction of the adjusting part, the depth of the fixing groove is C, and the distance between the upper end surface of the limiting part and the bottom of the fixing groove is D;

[0010] Wherein, C > D.

[0011] In some embodiments, along the radial direction of the adjusting part, the width of the fixing groove is E;

[0012] Wherein, 0° ≤ acos < 90°.

[0013] In some of these embodiments, a bearing portion is provided on the inner wall of the bushing, and the bearing portion is used to bear the sealing structure;

[0014] Along the axial direction of the adjusting portion, at least one of the sides of the fixing portion and the bearing portion facing each other is provided with a rib, and one end of the rib facing the sealing structure is embedded in the sealing structure.

[0015] In some of these embodiments, the cross-section of the rib is a tapered structure, and the small-mouth end of the tapered structure is arranged facing the sealing structure, so that the rib can be embedded in the rib;

[0016] And / or, the rib is arranged along the circumferential direction of the adjusting portion for circumferential limiting of the sealing structure.

[0017] In some of these embodiments, the rib includes a first limiting portion, and along the axial direction of the adjusting portion, the first limiting portion is arranged on the side of the fixing portion facing the bearing portion;

[0018] Wherein, along the radial direction of the adjusting portion, the distance between the central axis of the first limiting portion and the outer wall of the sealing structure is A1, and the thickness of the sealing structure is B1, wherein, 0.4B1 ≤ A1 ≤ 0.6B1.

[0019] In some of these embodiments, the rib includes a second limiting portion, and along the axial direction of the adjusting portion, the second limiting portion is arranged on the side of the bearing portion facing the fixing portion;

[0020] Wherein, along the radial direction of the adjusting portion, the distance between the central axis of the second limiting portion and the inner side wall of the bearing portion is A2, and the thickness of the bearing portion is B2, wherein, 0.4B2 ≤ A2 ≤ 0.6B2.

[0021] According to a second aspect of the present invention, an electronic expansion valve is provided, which includes a screw rod, a valve body, an elastic member and the above-mentioned valve needle assembly, the elastic member is arranged between the screw rod and the valve needle body, and the valve body is provided with a valve port;

[0022] Wherein, the screw rod is configured to be able to drive the valve needle assembly to move along the axial direction of the valve needle assembly, so that the adjusting portion of the valve needle assembly selectively blocks the valve port.

[0023] In some of these embodiments, a middleware is further included. The middleware includes a connecting portion and a first positioning portion. Along the axial direction of the valve needle assembly, the connecting portion is disposed on the side of the screw rod facing the valve needle assembly. The elastic member abuts against the connecting portion and the fixing portion respectively. The first positioning portion is disposed on the side of the connecting portion away from the screw rod, and the first positioning portion penetrates through the elastic member;

[0024] A sleeve is further included. The fixing portion penetrates through the sleeve, and one end of the bushing away from the adjusting portion is inserted into the sleeve and has an interference fit with the sleeve. The elastic member is disposed inside the sleeve;

[0025] Along the axial direction of the adjusting portion, the outer diameter of the first positioning portion is J. The fixing portion has a large-diameter end and a small-diameter end at the end away from the adjusting portion. A fixing groove is formed between the large-diameter end and the small-diameter end. The end face on the side of the small-diameter end away from the large-diameter end is the upper end face, the outer diameter of the upper end face is F, the outer diameter of the elastic member is G, the inner diameter of the elastic member is g, the wire diameter of the elastic member is d, and the unilateral radial clearance between the outer side wall of the connecting portion and the inner side wall of the sleeve is k;

[0026] Wherein, G + g + 2k - J - F < d.

[0027] In some of these embodiments, the valve needle body further includes a second positioning portion. Along the axial direction of the adjusting portion, the second positioning portion is disposed on the side of the fixing portion away from the adjusting portion, and the second positioning portion penetrates through the elastic member.

[0028] In some of these embodiments, a first protruding portion and a second protruding portion are provided on the side of the valve body facing the valve needle assembly. The valve needle assembly, the first protruding portion, and the second protruding portion are sleeved with each other. The first protruding portion is disposed between the valve needle assembly and the second protruding portion. The valve port is disposed on the first protruding portion. The second protruding portion is a tapered structure, and the small-diameter end of the second protruding portion faces the fixing portion;

[0029] Wherein, the inner diameter of the sealing structure of the valve needle assembly is D1, the outer diameter of the sealing structure of the valve needle assembly is D2, the inner diameter of the valve port is D3, the outer diameter of the first protruding portion is D4, and the outer diameter of the second protruding portion is D5;

[0030] Wherein, D1 ≤ D3, D4 ≤ D2 ≤ D5.

[0031] One embodiment of the present utility model has the following advantages or beneficial effects:

[0032] The valve needle assembly and electronic expansion valve provided in this embodiment change the fixing method between the fixing part of the valve needle body and the bushing from laser welding to riveting. The riveting method does not generate heat, reduces the risk of heat deformation of the sealing structure, improves the sealing effect of the valve needle assembly, and thus improves the service reliability of the sealing structure. At the same time, during riveting, the limiting part of the bushing bends along the radial direction of the adjusting part and towards the direction close to the fixing groove, so that the limiting part is arranged in the fixing groove. The fixing groove provides a accommodating space for the limiting part, so that the limiting part will eventually be hidden in the valve needle body. Compared with the existing laser weld that will interfere with the press-fitting, since the connection between the bushing and the valve needle body does not leak out or protrude, the risk of interference when the valve needle assembly is integrally press-fitted subsequently or contacts other adjacent components is avoided. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] For a better understanding of the present invention, reference may be made to the embodiments shown in the following drawings. The components in the drawings are not necessarily to scale, and related elements may be omitted to emphasize and clearly illustrate the technical features of the present invention. Additionally, related elements or components may have different arrangements as known in the art. Furthermore, in the drawings, the same reference numerals denote the same or similar components in each drawing. By describing its exemplary embodiments in detail with reference to the drawings, the above and other features and advantages of the present invention will become more apparent.

[0034] Wherein:

[0035] Figure 1 FIG. shows a schematic structural diagram of a valve needle assembly according to an embodiment of the present invention;

[0036] Figure 2 FIG. shows a schematic structural diagram of an electronic expansion valve according to an embodiment of the present invention;

[0037] Figure 3 FIG. shows Figure 2 a partial enlarged view at I.

[0038] Wherein, the reference numerals are explained as follows:

[0039] 1, valve needle body; 2, bushing; 3, sealing structure; 4, rib;

[0040] 11, adjusting part; 111, first section; 112, second section; 12, fixing part; 120, upper end face; 121, fixing groove; 1221, groove bottom; 1222, groove wall; 13, second positioning part;

[0041] 21, limiting part; 22, bearing part;

[0042] 31, first sealing part; 32, second sealing part;

[0043] 41. First limiting part; 42. Second limiting part;

[0044] 100. Valve needle assembly; 200. Screw; 300. Valve body; 301. Valve port; 302. First protrusion; 303. Second protrusion; 400. Elastic member; 500. Intermediate member; 501. Connecting part; 502. First positioning part; 600. Sleeve; 700. Bearing. Detailed implementation manners

[0045] Next, the technical solutions in the exemplary embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the exemplary embodiments of the present invention. The exemplary embodiments described herein are only for the purpose of illustration and are not intended to limit the protection scope of the present invention. Therefore, it should be understood that various modifications and changes can be made to the exemplary embodiments without departing from the protection scope of the present invention.

[0046] In the description of the present invention, unless otherwise clearly defined and limited, the terms "first" and "second" are only used for the purpose of description and cannot be understood as indicating or implying relative importance; the term "plurality" means two or more; the term "and / or" includes any combination and all combinations of one or more of the associated listed items. In particular, referring to "the / this" object or "one" object also intends to represent one of the possible multiple such objects.

[0047] Unless otherwise specified or described, the terms "connection", "fixation", etc. should be understood in a broad sense. For example, "connection" can be a fixed connection, a detachable connection, an integral connection, an electrical connection, or a signal connection; "connection" can be a direct connection or an indirect connection through an intermediate medium. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0048] Furthermore, in the description of the present invention, it should be understood that the orientation terms such as "upper", "lower", "inner", "outer", etc. described in the exemplary embodiments of the present invention are described from the angles shown in the accompanying drawings and should not be understood as limiting the exemplary embodiments of the present invention. It should also be understood that in the context, when referring to an element or feature being connected "on", "under", or "inside", "outside" another element (one or more), it can not only be directly connected "on", "under", or "inside", "outside" another (one or more) element, but also be indirectly connected "on", "under", or "inside", "outside" another (one or more) element through an intermediate element.

[0049] Example embodiments will now be described more fully with reference to the accompanying drawings. However, the example embodiments can be implemented in various forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this utility model will be thorough and complete, and will fully convey the concept of the example embodiments to those skilled in the art. Like reference numerals in the figures denote the same or similar structures, and thus their detailed description will be omitted.

[0050] This embodiment provides a valve needle assembly 100, which is applicable to the technical field of control valves, especially electronic expansion valves. As Figure 1 shown, the valve needle assembly 100 includes a valve needle body 1, a bushing 2, and a sealing structure 3. The valve needle body 1 includes an adjusting portion 11 and a fixing portion 12. The adjusting portion 11 cooperates with the valve port 301 (as Figure 2 shown). Along the axial direction of the adjusting portion 11, the adjusting portion 11 has a first section 111 and a second section 112. The second section 112 is located at one end of the first section 111 close to the valve port 301. The second section 112 has a tapered section. The adjusting portion 11 is used to selectively block the valve port 301, and the second section 112 of the adjusting portion 11 is used to adjust the flow rate of the valve port 301. Along the axial direction of the adjusting portion 11, one side of the fixing portion 12 is connected to the adjusting portion 11. The diameter of the adjusting portion 11 is smaller than the diameter of the fixing portion 12, so that the adjusting portion 11 and the fixing portion 12 form a similar T-shaped structure. The fixing portion 12 is used to install the bushing 2. The bushing 2 is sleeved outside the valve needle body 1, and the sealing structure 3 is sleeved outside the valve needle body 1 and arranged between the valve needle body 1 and the bushing 2 to ensure the sealing effect between the valve needle body 1 and the bushing 2. Among them, the sealing structure 3 can be an optional sealing ring, and the outer shape of the sealing ring can be a cylindrical structure or a similar T-shaped structure, etc.

[0051] During assembly, first press-fit the sealing structure 3 onto the outside of the valve needle body 1, that is, the sealing structure 3 is sleeved outside the adjusting portion 11 of the valve needle body 1, and the sealing structure 3 abuts against the step between the fixing portion 12 and the adjusting portion 11 to play a role in installation positioning. Then press the sealing structure 3 and the valve needle body 1 as a whole into the bushing 2. Laser welding can be used to fix between the bushing 2 and the fixing portion 12 of the valve needle body 1 to ensure that an integral structure is formed between the bushing 2 and the valve needle body 1.

[0052] If laser welding is used to fix between the bushing 2 and the valve needle body 1, the heat generated by laser welding will cause the sealing structure 3 to be thermally deformed, thereby affecting the sealing effect of the sealing structure 3.

[0053] To solve this problem, as Figure 1As shown, for the valve needle assembly 100 provided in this embodiment, along the axial direction of the adjusting portion 11, a fixing groove 121 is provided on the upper end surface 120 on the other side of the fixing portion 12. Along the axial direction of the adjusting portion 11, a limiting portion 21 is provided at one end of the bushing 2 away from the adjusting portion 11. The limiting portion 21 is configured to be bent along the radial direction of the adjusting portion 11 and towards the direction close to the fixing groove 121, so that the limiting portion 21 is arranged in the fixing groove 121. Among them, the limiting portion 21 can specifically be a riveting portion.

[0054] During assembly, the sealing structure 3 is press-fitted on the outside of the valve needle body 1, and the sealing structure 3 and the valve needle body 1 are press-fitted into the bushing 2 as a whole. Then, the fixing portion 12 of the bushing 2 and the valve needle body 1 are fixed through the limiting portion 21 to form an integral valve needle assembly 100.

[0055] For the valve needle assembly 100 provided in this embodiment, a fixed connection is directly achieved between the fixing portion 12 of the valve needle body 1 and the bushing 2 by the deformation of the limiting portion 21 of the bushing 2 and the insertion of the limiting portion 21 into the fixing groove 121 of the fixing portion 12. There is no need to use laser welding, no heat will be generated, the risk of heat deformation of the sealing structure 3 is reduced, the sealing effect of the valve needle assembly 100 is improved, and thus the service reliability of the sealing structure 3 is improved. At the same time, the fixing groove 121 provides a receiving space for the limiting portion 21. During riveting, the limiting portion 21 of the bushing 2 is bent along the radial direction of the adjusting portion 11 and towards the direction close to the fixing groove 121, so that the limiting portion 21 is arranged in the fixing groove 121, and the limiting portion 21 will eventually be hidden inside the valve needle body 1. Compared with the situation where the existing laser weld seam will interfere with the press-fitting, since the connection between the bushing 2 and the valve needle body 1 does not leak out and does not protrude, the risk of interference can be avoided when the valve needle assembly 100 is press-fitted as a whole subsequently or contacts other adjacent components.

[0056] Exemplarily, as Figure 1 shown, along the axial direction of the adjusting portion 11, the fixing groove 121 is provided on the end surface of the fixing portion 12 on the side away from the adjusting portion 11. Along the axial direction of the adjusting portion 11, the depth of the fixing groove 121 is C. During processing, the end surface of the fixing portion 12 on the side away from the adjusting portion 11 is recessed towards the direction close to the adjusting portion 11 to form the fixing groove 121, and the fixing groove 121 penetrates through the edge of the fixing portion 12, so that the tail of the fixing portion 12 has a step.

[0057] It can be understood that the fixing groove 121 can be arranged along the circumferential direction of the adjusting portion 11, and the fixing groove 121 is an annular structure; there can also be multiple fixing grooves 121, and the multiple fixing grooves 121 are circumferentially distributed and spaced along the adjusting portion 11, and multiple limiting portions 21 are correspondingly arranged in the multiple fixing grooves 121.

[0058] Exemplarily, along the axial direction of the adjusting portion 11, the limiting portion 21 is disposed on the side of the bushing 2 away from the adjusting portion 11. The limiting portion 21 and the bushing 2 can be an integrally formed structure, reducing the parts assembly process. The limiting portion 21 is correspondingly disposed with the fixing groove 121. Specifically, after the valve needle body 1 is press-fitted into the bushing 2 and before the limiting portion 21 deforms, along the axial direction of the adjusting portion 11, the distance between the upper end surface of the limiting portion 21 and the bottom of the fixing groove 121 is D. During riveting, taking the connection position between the fixing groove 121 and the outer peripheral wall of the fixing portion 12 as a fulcrum, the limiting portion 21 is bent along the radial direction of the adjusting portion 11 to achieve the effect of internal riveting.

[0059] Wherein, C > D. That is, the depth of the fixing groove 121 is greater than the distance D between the upper end surface of the limiting portion 21 and the bottom of the fixing groove 121, or, before the limiting portion 21 deforms, the projection on the first reference plane is located inside the projection of the fixing groove 121 on the first reference plane, and the first reference plane is parallel to the axial direction of the adjusting portion 11. In this way, after being bent, the limiting portion 21 can only be limited within the fixing groove 121, and will not cover the upper end surface 120 on the side of the fixing portion 12 away from the adjusting portion 11, avoiding interference with other components located on the fixing portion 12.

[0060] In one embodiment, along the radial direction of the adjusting portion 11, the width of the fixing groove 121 is E, wherein 0° ≤ acos(E / D) < 90°.

[0061] It can be understood that in this way, the width E of the fixing groove 121 is greater than or equal to the distance D between the upper end surface of the limiting portion 21 and the bottom of the fixing groove 121. The fixing groove 121 can fully accommodate the limiting portion 21. After being bent, the limiting portion 21 will only cover the bottom of the fixing groove 121, or extend to the connection position between the bottom 1221 and the wall 1222 of the fixing groove 121, improving the riveting and fixing effect and ensuring the connection stability between the bushing 2 and the valve needle assembly 100. It can be understood that the limiting portion 21 will not extend to the wall 1222 of the fixing groove 121, and can also avoid the situation that the edge of the limiting portion 21 warps due to multiple folds.

[0062] In one embodiment, as Figure 1 shown, a bearing portion 22 is provided on the inner wall of the bushing 2. The bearing portion 22 is used to bear the sealing structure 3, and the bearing portion 22 can provide a certain supporting force for the sealing structure 3.

[0063] Among them, the material of the sealing structure 3 is relatively soft. For example, elastic materials such as rubber have certain deformation ability and sealing performance. Specifically, the sealing structure 3 includes a first sealing portion 31 and a second sealing portion 32. The adjusting portion 11 of the valve needle body 1 coaxially penetrates through the first sealing portion 31 and the second sealing portion 32. The outer diameter of the first sealing portion 31 is greater than that of the second sealing portion 32, so that the cross-section of the sealing structure 3 forms a structure similar to a T shape. The first sealing portion 31 is sleeved outside the adjusting portion 11 and is arranged between the fixing portion 12, the bushing 2 and the bearing portion 22, and the bearing portion 22 is used to bear the first sealing portion 31. The second sealing portion 32 is sleeved outside the adjusting portion 11 and is arranged between the adjusting portion 11 and the bushing 2.

[0064] Among them, as Figure 1 shown, along the axial direction of the adjusting portion 11, at least one of the sides of the fixing portion 12 and the bearing portion 22 facing each other is provided with a rib 4. One end of the rib 4 facing the sealing structure 3 can be embedded into the sealing structure 3, and the rib 4 is used for limiting the sealing structure 3.

[0065] Exemplarily, the rib 4 can be only arranged on the fixing portion 12, and the rib 4 protrudes from the end face of the fixing portion 12 facing the bearing portion 22 towards the bearing portion 22 to limit the upper end face of the sealing structure 3 along the axial direction of the adjusting portion 11; the rib 4 can also be only arranged on the bearing portion 22, and the rib protrudes from the end face of the bearing portion 22 facing the fixing portion 12 towards the fixing portion 12 to limit the lower end face of the sealing structure 3 along the axial direction of the adjusting portion 11. The rib 4 can also be respectively arranged on the fixing portion 12 and the bearing portion 22 to limit the upper and lower end faces of the sealing structure 3 along the axial direction of the adjusting portion 11.

[0066] In addition, it should be particularly noted that at low temperatures, the shrinkage amount of the sealing structure 3 made of PTFE material along the axial direction of the adjusting portion 11 is greater than the shrinkage amount along the radial direction of the adjusting portion 11. When the sealing structure 3 shrinks along the axial direction of the adjusting portion 11, the refrigerant may migrate through the gaps between the sealing structure 3, the bushing 2 and the valve needle body 1, resulting in leakage. By providing the rib 4, the rib 4 is equivalent to an additional layer of blocking protection, that is, the rib 4 serves as a waterproof rib, and even if axial shrinkage occurs, the effect of blocking the refrigerant can be achieved. Among them, the cross-section of the rib 4 is a tapered structure, and the small-diameter end of the tapered structure faces the sealing structure 3, so that the small-diameter end of the rib 4 can be embedded into the rib of the sealing structure 3;

[0067] For example, the cross-section of the rib 4 is a triangular structure. After press-fitting, the rib 4 can be inserted into the relatively soft sealing structure 3 to prevent the sealing structure 3 from moving. It can be understood that the cross-section of the rib 4 can also be other shaped structures, as long as one end of the rib 4 facing the sealing structure 3 can be embedded into the sealing structure 3, it is within the protection scope of this embodiment.

[0068] Among them, the convex rib 4 is arranged along the circumferential direction of the adjusting part 11, that is, the convex rib 4 is an annular protrusion, which is used for the circumferential limit of the sealing structure 3 to prevent the sealing structure 3 from rotating circumferentially. At the same time, by using the sealing structure 3, the sealing effect of the entire valve needle assembly 100 after thermal expansion and contraction can also be ensured, preventing the refrigerant from migrating through the gap between the sealing structure 3, the valve needle body 1 and the bushing 2.

[0069] Specifically, as Figure 1 shown, the convex rib 4 includes a first limiting part 41. Along the axial direction of the adjusting part 11, the first limiting part 41 is arranged on the side of the fixing part 12 facing the bearing part 22. That is, along the axial direction of the adjusting part 11, the first limiting part 41 protrudes from the lower end surface of the fixing part 12. The first limiting part 41 and the fixing part 12 can be an integrally formed structure, reducing the part assembly link and saving production costs.

[0070] Among them, along the radial direction of the adjusting part 11, the distance between the central axis of the first limiting part 41 and the outer wall of the sealing structure 3 is A1, and the thickness of the sealing structure 3 is B1, where 0.4B1 ≤ A1 ≤ 0.6B1. For example, A1 can be selected as 0.4B1, 0.5B1, 0.6B1, etc., preferably 0.5B1.

[0071] The contact surface between the fixing part 12 and the sealing structure 3 is the first annular surface. In this way, it is equivalent to that the first limiting part 41 is located in the middle position of the first annular surface, improving the fixing balance of the first limiting part 41 to the sealing structure 3, and further improving the sealing effect between the bushing 2, the sealing structure 3 and the valve needle body 1 while preventing the sealing structure 3 from rotating circumferentially.

[0072] In one embodiment, the convex rib 4 includes a second limiting part 42. Along the axial direction of the adjusting part 11, the second limiting part 42 is arranged on the side of the bearing part 22 facing the fixing part 12. That is, along the axial direction of the adjusting part 11, the first limiting part 41 protrudes from the upper end surface of the bearing part 22. The second limiting part 42 and the bearing part 22 can be an integrally formed structure, reducing the part assembly link and saving production costs.

[0073] Among them, along the radial direction of the adjusting part 11, the distance between the central axis of the second limiting part 42 and the inner wall of the bearing part 22 is A2, and the thickness of the bearing part 22 is B2, where 0.4B2 ≤ A2 ≤ 0.6B2. For example, A2 can be selected as 0.4B2, 0.5B2, 0.6B2, etc., preferably 0.5B2.

[0074] The contact surface between the bearing part 22 and the sealing structure 3 is the second annular surface. In this way, it is equivalent that the second limiting part 42 is located at the middle position of the second annular surface, improving the fixing balance of the second limiting part 42 to the sealing structure 3. While preventing the sealing structure 3 from rotating circumferentially, it can further improve the sealing effect between the bushing 2, the sealing structure 3 and the valve needle body 1.

[0075] This embodiment also provides an electronic expansion valve. As Figure 2 shown, the electronic expansion valve includes a screw 200, a valve body 300, an elastic member 400 and the above-mentioned valve needle assembly 100. The elastic member 400 can be a cylindrical spring, etc. The elastic member 400 is arranged between the screw 200 and the valve needle body 1, and the valve body 300 is provided with a valve port 301. Among them, the screw 200 is configured to be able to drive the valve needle assembly 100 to move along the axial direction of the valve needle assembly 100, so that the adjusting part 11 of the valve needle assembly 100 selectively blocks the valve port 301.

[0076] By arranging the elastic member 400 between the screw 200 and the valve needle body 1, when the valve needle assembly 100 opens or closes the valve port 301, the elastic member 400 plays a buffering role in the movement of the valve needle body 1, ensuring the smooth opening of the valve needle body 1.

[0077] In addition, the axial direction of the valve needle assembly 100 is the axial direction of the adjusting part 11. When the valve needle assembly 100 opens or closes the valve port 301, the lower end of the elastic member 400 abuts against the upper end surface of the fixing part 12 of the valve needle body 1.

[0078] It should be particularly noted that since the riveting size is relatively difficult to accurately control, the limiting part 21 of the bushing 2 is riveted and bent into the fixing groove 121 of the fixing part 12, so that the limiting part 21, as the riveting flange formed after bending, will not interfere with the elastic member 400, reducing the risk of the elastic member 400 getting stuck, thereby improving the use reliability of the electronic expansion valve.

[0079] In one embodiment, as Figure 2 - Figure 3 shown, a first protruding part 302 and a second protruding part 303 are arranged on one side of the valve body 300 facing the valve needle assembly 100. The first protruding part 302 is arranged between the valve needle assembly 100 and the second protruding part 303, and the valve port 301 is arranged on the first protruding part 302.

[0080] The first protruding part 302 and the second protruding part 303 form an annular protruding structure, which is used to abut and cooperate with the end surface of the sealing structure 3 facing the valve port 301, so as to ensure the sealing effect of the sealing structure 3 on the valve port 301.

[0081] Specifically, the outer shape of the first protrusion 302 is similar to a cylindrical structure. The end face of the sealing structure 3 facing the valve port 301 abuts against the first protrusion 302 to ensure the sealing effect of the valve port 301. The first protrusion 302 is connected to the second protrusion 303, and the second protrusion 303 is a tapered structure. The small-end of the second protrusion 303 faces the fixing portion 12. That is, along the axial direction of the adjusting portion 11 and away from the sealing structure 3, the outer diameter of the second protrusion 303 gradually increases. The end face of the sealing structure 3 facing the valve port 301 can at least partially abut against the second protrusion 303, which can further ensure the sealing effect while ensuring the flow rate adjustment accuracy of the valve port 301 to a certain extent.

[0082] In one embodiment, as Figure 2 - Figure 3 shown, the inner diameter of the sealing structure 3 of the valve needle assembly 100 is D1. Here, D1 is the inner diameter when the sealing structure 3 is assembled onto the valve needle body 1. Specifically, the sealing structure 3 is assembled onto the first section 111, and the second section 112 is conical. The inner diameter of the sealing structure 3 is adapted to the outer diameter of the first section 111 of the adjusting portion 11 on the valve needle body 1. The inner diameter of the valve port 301 is D3, and D1 ≤ D3. That is, the inner diameter D3 of the sealing structure 3 is less than or equal to the inner diameter of the valve port 301, so that when the valve needle assembly 100 closes the valve port 301, it can prevent interference between the outer side wall of the adjusting portion 11 of the valve needle assembly 100 and the valve port 301. The end face of the sealing structure 3 facing the valve port 301 can block the gap between the adjusting portion 11 and the valve port 301, realizing the sealing effect of the sealing structure 3 on the valve port 301.

[0083] In one embodiment, the outer diameter of the sealing structure 3 of the valve needle assembly 100 is D2, the outer diameter of the first protrusion 302 is D4, and the outer diameter of the second protrusion 303 is D5; D4 ≤ D2 ≤ D5. In this way, when the valve needle assembly 100 closes the valve port 301, the side of the end face of the sealing structure 3 facing away from the center of the adjusting portion 11 and facing the valve port 301 can deform towards the inclined side wall surface of the second protrusion 303, further ensuring the sealing effect.

[0084] In one embodiment, as Figure 2 - Figure 3 shown, the electronic expansion valve further includes a sleeve 600. The fixing portion 12 of the valve needle body 1 passes through the sleeve 600, and one end of the bushing 2 away from the adjusting portion 11 is inserted into the sleeve 600 and has an interference fit with the sleeve 600. The bushing 2 and the sleeve 600 can also be fixed by laser welding. The elastic member 400 is arranged in the sleeve 600. The sleeve 600 provides an installation and movement space for the elastic member 400, and the sleeve 600 can also be called a spring sleeve.

[0085] It should be particularly noted that if the fixing part 12 of the valve needle body 1 and the bushing 2 are laser welded, affected by the forming thickness of the laser weld, the weld will protrude from the outer wall edge of the bushing 2. When the valve needle assembly 100 is integrally press-fitted into the sleeve 600, the weld will interfere with the inner wall of the sleeve 600, thereby affecting the press-fitting between the valve needle assembly 100 and the sleeve 600. However, the fixing part 12 of the valve needle body 1 and the bushing 2 in the present application are fixed by riveting, avoiding the interference when the valve needle assembly 100 is press-fitted into the sleeve 600.

[0086] In one embodiment, the electronic expansion valve further includes a bearing 700. The bearing 700 is arranged in the sleeve 600 and at one end of the elastic member 400 away from the valve needle body 1. The outer ring of the bearing 700 is in clearance fit with the inner peripheral surface of the sleeve 600. One end of the screw 200 passes through the inner ring of the bearing 700 and is fixedly connected to the inner ring of the bearing 700. With such a setting, it can be ensured that the valve needle body 1 only moves linearly during the opening and closing process, ensuring the smoothness of the valve opening and closing processes.

[0087] In one embodiment, the electronic expansion valve further includes an intermediate member 500. The intermediate member 500 is arranged between the bearing 700 and the valve needle body 1. Both ends of the elastic member 400 respectively abut against the intermediate member 500 and the fixing part 12 of the valve needle body 1. The intermediate member 500 provides an abutting position for the elastic member 400, increasing the contact area with the elastic member 400. The intermediate member 500 can also be called a gasket.

[0088] Specifically, the intermediate member 500 includes a connecting part 501. The screw 200 is connected to the connecting part 501 through the bearing 700, that is, along the axial direction of the valve needle assembly 100, the connecting part 501 is arranged on the side of the screw 200 facing the valve needle assembly 100. The elastic member 400 respectively abuts against the connecting part 501 and the fixing part 12. The connecting part 501 increases the contact area with the elastic member 400, ensuring that the power generated by the screw 200 can be transmitted to the elastic member 400 through the connecting part 501. The elastic member 400 drives the valve needle assembly 100 to move towards the direction close to the valve port 301. In addition, the elastic member 400 also plays a role in buffering and resetting the valve needle assembly 100.

[0089] Specifically, as Figure 3 shown, the intermediate member 500 further includes a first positioning part 502. The first positioning part 502 is arranged on the side of the connecting part 501 away from the screw 200. The first positioning part 502 passes through the elastic member 400. Along the axial direction of the adjusting part 11, the upper part of the elastic member 400 can be positioned by using the first positioning part 502, avoiding the situation that the elastic member 400 has a large position deviation during the operation of the electronic expansion valve.

[0090] In one embodiment, along the axial direction of the adjusting portion 11, the outer diameter of the first positioning portion 502 is J, the outer diameter of the end surface of the fixing portion 12 away from the adjusting portion 11 is F, the outer diameter of the elastic member 400 is G, the inner diameter of the elastic member 400 is g, the wire diameter of the elastic member 400 is d, and the radial clearance between the outer wall of the connecting portion 501 and the inner wall of the sleeve 600 is k. Among them, (G / 2+(gJ) / 2+k)-F / 2<d / 2.

[0091] It can be understood that gJ is the radial clearance between the inner diameter of the elastic member 400 and the first positioning portion 502, (gJ) / 2) is the unilateral radial clearance between the inner diameter of the elastic member 400 and the first positioning portion 502. For example, when the elastic member 400 is extremely offset to the right along the radial direction of the adjustment portion 11, the left inner wall of the elastic member 400 is in contact with the first positioning portion 502, then the elastic member 400 protrudes to the right along the radial direction of the adjustment portion 11, and the protrusion amount is (gJ) / 2, G / 2 is the initial outer wall radius of the elastic member 400, and k is the radius of the intermediate member 500. The unilateral radial clearance between the outer wall of the connecting part 501 and the inner wall of the sleeve 600 is assumed that the intermediate part 500 also undergoes radial limit displacement during the operation of the electronic expansion valve, and the direction of the radial displacement is the same as the direction of the radial limit displacement of the elastic part 400. Then k is the maximum radial displacement dimension of the connecting part 501, and (gJ) / 2+k is the maximum radial protrusion of the outer wall of the elastic part 400 in a certain direction when the elastic part 400 is in the radial limit displacement position (i.e., the intermediate part 500 and the elastic part 400 both undergo radial limit displacement, and the displacement directions are consistent).

[0092] In one embodiment, both the intermediate member 500 and the elastic member 400 are radially offset to the right to the maximum extent. After the maximum offset, the right side portion of the elastic member 400 must be at least partially located on the upper end surface 120 of the fixing portion 12 after the offset, that is, the right side portion of the elastic member 400 may be separated from the upper end surface of the fixing portion 12 and suspended relative to the fixing portion 12. (G / 2+(gJ) / 2)-F / 2 is the distance that the right side portion of the elastic member 400 is separated from the upper end surface of the fixing portion 12. If the distance is greater than or equal to d, the elastic member 400 will completely separate from the upper end surface of the fixing portion 12.

[0093] If (G / 2 + (g - J) / 2 + k) - F / 2 ≥ d / 2, after the elastic member 400 undergoes a radial offset, it may partially disengage from the upper end surface of the fixing portion 12 and get stuck at the junction of the upper end surface of the fixing portion 12 and the limiting portion 121. Therefore, by setting (G / 2 + (g - J) / 2 + k) - F / 2 < d / 2, even if the elastic member 400 undergoes a limit offset, it can ensure that the lower end surface of the elastic member 400 effectively abuts against the end surface of the fixing portion 12 on the side away from the adjusting portion 11, preventing the elastic member 400 from tilting and disengaging from the end surface of the fixing portion 12 on the side away from the adjusting portion 11. After converting the formula (G / 2 + (g - J) / 2 + k) - F / 2 < d / 2, we can obtain G + g + 2k - J - F < d.

[0094] In one embodiment, as Figure 3 shown, the valve needle body 1 further includes a second positioning portion 13. Along the axial direction of the adjusting portion 11, the second positioning portion 13 is arranged on the side of the fixing portion 12 away from the adjusting portion 11, and the second positioning portion 13 passes through the elastic member 400. Along the axial direction of the adjusting portion 11, the second positioning portion 13 can be used to position the lower part of the elastic member 400, avoiding a large position offset of the elastic member 400.

[0095] It should be noted here that what is shown in the drawings and described in this specification is only an example of applying the principle of the present invention. Those of ordinary skill in the art should clearly understand that the principle of the present invention is not limited to any details of the device shown in the drawings or described in the specification or any components.

[0096] It should be understood that the present invention does not limit its application to the detailed structure and arrangement of the components proposed in this specification. The present invention can have other embodiments and can be implemented and executed in various ways. The foregoing variations and modifications fall within the scope of the present invention. It should be understood that the present invention disclosed and defined in this specification extends to all alternative combinations of two or more separate features mentioned or obvious in the text and / or drawings. All these different combinations constitute multiple alternative aspects of the present invention. The embodiments described in this specification illustrate the best mode known for implementing the present invention and will enable those skilled in the art to utilize the present invention.

[0097] Other embodiments of the present utility model will be readily contemplated by those skilled in the art upon considering the specification and practicing the invention disclosed herein. The present utility model is intended to cover any variations, uses, or adaptations of the present utility model, which follow the general principles of the present utility model and include known common knowledge or conventional technical means in the technical field not disclosed by the present utility model. The specification and the exemplary embodiments are only regarded as exemplary, and the true scope and spirit of the present utility model are pointed out by the appended claims.

[0098] It should be understood that the present utility model is not limited to the exact structures described above and shown in the drawings, and various modifications and changes can be made without departing from its scope. The protection scope of the present utility model is only limited by the appended claims.

Claims

1. A valve needle assembly, characterized in that, Comprising: A valve needle body (1), including an adjusting portion (11) and a fixing portion (12), the adjusting portion (11) being used for selectively plugging the valve port (301), along the axial direction of the adjusting portion (11), one side of the fixing portion (12) is connected to the adjusting portion (11), and a fixing groove (121) is provided on the upper end surface (120) of the other side of the fixing portion (12); A bushing (2), sleeved outside the valve needle body (1), along the axial direction of the adjusting portion (11), a limiting portion (21) is provided at one end of the bushing (2) away from the adjusting portion (11), and the limiting portion (21) is configured to be able to bend along the radial direction of the adjusting portion (11) and towards the fixing groove (121), so that the limiting portion (21) is arranged in the fixing groove (121); A sealing structure (3), sleeved outside the valve needle body (1) and arranged between the valve needle body (1) and the bushing (2).

2. The valve needle assembly according to claim 1, wherein, Along the axial direction of the adjusting portion (11), the depth of the fixing groove (121) is C, and the distance between the upper end surface of the limiting portion (21) and the bottom of the fixing groove (121) is D; Wherein, C > D.

3. The valve needle assembly according to claim 2, characterized in that, Along the radial direction of the adjusting portion (11), the width of the fixing groove (121) is E; Wherein, 0° ≤ acos(E / D) < 90°.

4. The valve needle assembly according to claim 1, wherein, A bearing portion (22) is provided on the inner wall of the bushing (2), and the bearing portion (22) is used for bearing the sealing structure (3); Along the axial direction of the adjusting portion (11), at least one of the sides of the fixing portion (12) and the bearing portion (22) facing each other is provided with a rib (4), and one end of the rib (4) facing the sealing structure (3) is embedded in the sealing structure (3).

5. The valve needle assembly according to claim 4, characterized in that, The cross-section of the rib (4) is a tapered structure, and the small-end of the tapered structure is arranged facing the sealing structure (3), so that the rib (4) can be embedded in the rib (4); And / or, the rib (4) is arranged along the circumferential direction of the adjusting portion (11) for circumferential limiting of the sealing structure (3).

6. The valve needle assembly according to claim 4, wherein, The rib (4) includes a first limiting portion (41), along the axial direction of the adjusting portion (11), the first limiting portion (41) is arranged on the side of the fixing portion (12) facing the bearing portion (22); Wherein, along the radial direction of the adjusting portion (11), the distance between the central axis of the first limiting portion (41) and the outer wall of the sealing structure (3) is A1, and the thickness of the sealing structure (3) is B1, wherein, 0.4B1 ≤ A1 ≤ 0.6B1.

7. The valve needle assembly according to claim 4, characterized in that, The rib (4) includes a second limiting portion (42), along the axial direction of the adjusting portion (11), the second limiting portion (42) is arranged on the side of the bearing portion (22) facing the fixing portion (12); Wherein, along the radial direction of the adjusting portion (11), the distance between the central axis of the second limiting portion (42) and the inner side wall of the bearing portion (22) is A2, and the thickness of the bearing portion (22) is B2, wherein 0.4B2 ≤ A2 ≤ 0.6B2.

8. An electronic expansion valve, characterized in that, It includes a screw rod (200), a valve body (300), an elastic member (400), and a valve needle assembly as described in any one of claims 1 to 7. The elastic member (400) is disposed between the screw rod (200) and the valve needle body (1), and the valve body (300) is provided with a valve port (301). Wherein, the screw rod (200) is configured to be able to drive the valve needle assembly to move along the axial direction of the valve needle assembly, so that the adjusting portion (11) of the valve needle assembly selectively blocks the valve port (301).

9. The electronic expansion valve according to claim 8, characterized in that, It further includes an intermediate member (500). The intermediate member (500) includes a connecting portion (501) and a first positioning portion (502). Along the axial direction of the valve needle assembly, the connecting portion (501) is disposed on the side of the screw rod (200) facing the valve needle assembly. The elastic member (400) abuts against the connecting portion (501) and the fixing portion (12) respectively. The first positioning portion (502) is disposed on the side of the connecting portion (501) away from the screw rod (200), and the first positioning portion (502) passes through the elastic member (400). It further includes a sleeve (600). The fixing portion (12) passes through the sleeve (600), and one end of the bushing (2) away from the adjusting portion (11) is inserted into the sleeve (600) and is in interference fit with the sleeve (600). The elastic member (400) is disposed inside the sleeve (600). Along the axial direction of the adjusting portion (11), the outer diameter of the first positioning portion (502) is J. The fixing portion (12) has a large-diameter end and a small-diameter end away from the adjusting portion (11). A fixing groove (121) is formed between the large-diameter end and the small-diameter end. The end face on the side of the small-diameter end away from the large-diameter end is the upper end face, and the outer diameter of the upper end face is F. The outer diameter of the elastic member (400) is G, the inner diameter of the elastic member (400) is g, the wire diameter of the elastic member (400) is d, and the unilateral radial clearance between the outer side wall of the connecting portion (501) and the inner side wall of the sleeve (600) is k. Wherein, G + g + 2k - J - F < d.

10. The electronic expansion valve according to claim 8, characterized in that, The valve needle body (1) further includes a second positioning portion (13). Along the axial direction of the adjusting portion (11), the second positioning portion (13) is disposed on the side of the fixing portion (12) away from the adjusting portion (11), and the second positioning portion (13) passes through the elastic member (400).

11. The electronic expansion valve according to claim 8, wherein, On one side of the valve body (300) facing the valve needle assembly, a first protrusion (302) and a second protrusion (303) are provided. The valve needle assembly, the first protrusion (302), and the second protrusion (303) are sleeved with each other. The first protrusion (302) is disposed between the valve needle assembly and the second protrusion (303). The valve port (301) is disposed on the first protrusion (302). The second protrusion (303) is a tapered structure, and the small end of the second protrusion (303) faces the fixed part (12). Wherein, the inner diameter of the sealing structure (3) of the valve needle assembly is D1, the outer diameter of the sealing structure (3) of the valve needle assembly is D2, the inner diameter of the valve port (301) is D3, the outer diameter of the first protrusion (302) is D4, and the outer diameter of the second protrusion (303) is D5; Wherein, D1≤D3, D4≤D2≤D5.

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