Electronic expansion valve

Abstract

The electronic expansion valve comprises a valve port portion provided with a valve port and a valve needle assembly, the valve needle assembly comprises a valve needle and a sealing piece, the sealing piece is connected to the end, close to the valve port portion, of the valve needle, the sealing piece can move by a preset distance in the axial direction relative to the valve needle, and at least one of the opposite end walls of the valve needle and the sealing piece is provided with an annular protrusion. In the valve closing state, the sealing piece and the valve port part are in abutting sealing, the valve needle and the sealing piece are in abutting sealing through the annular protrusion, and the hardness of the sealing piece is lower than that of the valve port part. According to the electronic expansion valve, the sealing piece is matched with the valve port in a soft sealing mode, the sealing performance is improved, and the inner leakage performance of a system can meet the requirement for low leakage amount; the valve needle and the sealing piece are sealed in an abutting mode through the annular protrusion, an expansion gap is formed between the opposite end walls of the valve needle and the sealing piece, the sealing piece can move in the axial direction relative to the valve needle, the impact force of an expansion medium on the valve needle and the sealing piece is relieved, and the connecting stability of the valve needle and the sealing piece is guaranteed.

Description

Technical Field

[0001] The utility model relates to the technical field of refrigeration control, and particularly relates to an electronic expansion valve. Background Art

[0002] As a throttling element, the electronic expansion valve is widely used in a refrigeration system to regulate the flow rate of the refrigerant. The structure of the electronic expansion valve in the background art is as Figure 1 shown. The angle between the valve needle 1' and the valve port A' is approximate. The valve needle 1' is abutted against the valve port A' under the driving force, and effective sealing is achieved through a metal hard sealing method. However, this sealing method has high requirements for the machining accuracy of the metal valve needle 1'.

[0003] Therefore, how to provide an electronic expansion valve to reduce the machining accuracy requirements, ensure the sealing effect, and make the internal leakage performance of the system meet the requirements of low leakage amount is a technical problem that needs to be solved urgently by those skilled in the art. Summary of the Utility Model

[0004] The purpose of the utility model is to provide an electronic expansion valve to reduce the machining accuracy requirements, ensure the sealing effect, and make the internal leakage performance of the system meet the requirements of low leakage amount.

[0005] To solve the above technical problems, the utility model provides an electronic expansion valve, which includes a valve port part provided with a valve port and a valve needle assembly.

[0006] The valve needle assembly includes a valve needle and a seal. The seal is connected to one end of the valve needle close to the valve port part. The seal can axially move a preset distance relative to the valve needle. At least one of the opposite end walls of the valve needle and the seal is provided with an annular protrusion. In the valve closed state, the seal abuts against and seals the valve port part, the valve needle and the seal abut against and seal through the annular protrusion, and the hardness of the seal is lower than that of the valve port part.

[0007] The technical effects of the utility model are as follows:

[0008] In the electronic expansion valve of the utility model, the valve needle assembly adopts a split structure of the valve needle and the seal, and the hardness of the seal is lower than that of the valve port part. Therefore, during the valve closing process, the seal will first abut against the valve port part and generate a certain deformation following the sealing sub-line of the valve port part, that is, a soft sealing fit is formed between the seal and the valve port part; then, the seal moves axially closer to the valve needle until the valve needle and the seal abut against and seal through the annular protrusion, ensuring the sealing effect and realizing the valve closing action. It can be seen that the electronic expansion valve of the utility model improves the sealing performance through the soft sealing fit between the seal and the valve port part, makes the internal leakage performance of the system meet the requirements of low leakage amount, reduces the machining accuracy requirements of the valve needle assembly, ensures the working reliability of the electronic expansion valve, and the accuracy of the medium flow rate control.

[0009] In addition, according to tests, it is found that if the end walls of the valve needle and the seal are in contact and relatively fixed, the medium may still enter between the end walls of the valve needle and the seal through the axial through-hole of the valve needle assembly. When the medium alternates between hot and cold, the medium stored between the valve needle and the seal will expand, causing an impact on the connection between the valve needle and the seal and affecting the connection stability between the two. Based on this, in this embodiment, at least one of the end walls of the valve needle and the seal is provided with an annular protrusion, and the seal can move axially relative to the valve needle by a preset distance, forming an expansion gap between the end walls of the valve needle and the seal. In the open valve state, the seal can move axially when subjected to the impact force of the expanding medium, alleviating the impact of the impact force on the connection state between the valve needle and the seal and ensuring the connection stability between the valve needle and the seal. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 is a schematic structural diagram of an electronic expansion valve in the prior art;

[0011] Figure 2 is a schematic structural diagram of the first specific embodiment of the electronic expansion valve provided by the present invention;

[0012] Figure 3 is Figure 2 a partial enlarged view of;

[0013] Figure 4 is a schematic structural diagram of the second specific embodiment of the electronic expansion valve provided by the present invention;

[0014] Figure 5 is Figure 4 a partial enlarged view of;

[0015] Figure 6 is a schematic structural diagram of the third specific embodiment of the electronic expansion valve provided by the present invention;

[0016] Figure 7 is Figure 6 a partial enlarged view of;

[0017] Among them, Figure 1 the reference numerals in

[0018] 1'-valve needle; A'-valve port;

[0019] Among them, Figures 2 - 7 the reference numerals in

[0020] 1-valve needle assembly; 11-valve needle; 12-seal; 13-connecting sleeve; 131-limiting part; 14-elastic member; a-annular protrusion; A-valve port part. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0021] To enable those skilled in the art to better understand the technical solution of the present utility model, the present utility model will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0022] As used herein, "a plurality" generally means more than two; and when "a plurality" is used to represent the quantity of several components, it does not represent the mutual relationship in quantity of these components.

[0023] Please refer to Figures 2 - 3 , Figure 2 which is a schematic structural diagram of the first specific embodiment of the electronic expansion valve provided by the present utility model; Figure 3 is Figure 2 a partial enlarged view of

[0024] The present utility model provides an electronic expansion valve, which includes a valve port part A provided with a valve port, and a valve needle assembly 1. The valve needle assembly 1 includes a valve needle 11 and a seal 12. The seal 12 is connected to one end of the valve needle 11 close to the valve port part A. The seal 12 can move axially relative to the valve needle 11 by a preset distance. At least one of the opposite end walls of the valve needle 11 and the seal 12 is provided with an annular protrusion a. In the valve-closed state, the seal 12 abuts against and seals the valve port part A, and the valve needle 11 and the seal 12 abut against and seal through the annular protrusion a. The hardness of the seal 12 is lower than that of the valve port part A.

[0025] In the electronic expansion valve of the present utility model, the valve needle assembly 1 adopts a split structure of the valve needle 11 and the seal 12, and the hardness of the seal 12 is lower than that of the valve port part A. Therefore, during the valve-closing process, the seal 12 will first abut against the valve port part A and generate a certain deformation following the sealing sub-line of the valve port part A, that is, a soft-sealing fit is formed between the seal 12 and the valve port part A; then, the seal 12 moves axially closer to the valve needle 11 until the valve needle 11 and the seal 12 abut against and seal through the annular protrusion a, ensuring the sealing effect and realizing the valve-closing action.

[0026] It can be seen that in the electronic expansion valve of the present utility model, the soft-sealing fit between the valve needle assembly 1 and the valve port part A can effectively improve the sealing performance of the electronic expansion valve, enabling the internal leakage performance of the system to meet the requirement of low leakage, reducing the processing precision requirement of the valve needle assembly 1, ensuring the working reliability of the electronic expansion valve, and the accuracy of the medium flow control; the seal 12 can be separately processed and formed by injection molding or other methods, with high processing efficiency and low processing difficulty.

[0027] In addition, in order to improve the operating performance of the valve needle assembly 1, the valve needle assembly 1 is usually provided with an axial through hole. According to tests, it is found that even if the end walls of the valve needle 11 and the seal 12 are in contact and relatively fixed, the medium may still enter between the opposite end walls of the valve needle 11 and the seal 12 through the axial through hole. When the medium alternates between hot and cold, the medium stored between the valve needle 11 and the seal 12 will expand, impacting the connection between the valve needle 11 and the seal 12 and affecting the connection stability between the two. Based on this, in this embodiment, at least one of the opposite end walls of the valve needle 11 and the seal 12 is provided with an annular protrusion a, and the seal 12 can axially move relative to the valve needle 11 by a preset distance. In the valve-closed state, the valve needle 11 and the seal 12 are in sealing contact through the annular protrusion a to ensure the sealing effect. At the same time, there is a certain gap between the opposite end walls of the valve needle 11 and the seal 12. When the medium alternates between hot and cold, this gap forms an expansion space. In the valve-open state, the seal 12 can axially move when subjected to the impact force of the expanding medium, alleviating the impact of the force on the connection state between the valve needle 11 and the seal 12 and ensuring the connection stability between the valve needle 11 and the seal 12.

[0028] As described above, at least one of the opposite end walls of the valve needle 11 and the seal 12 is provided with an annular protrusion a, and two setting methods of the annular protrusion a are provided in this application.

[0029] Please refer to Figures 3 - 5 , Figure 4 which is a schematic structural diagram of the second specific embodiment of the electronic expansion valve provided by the present utility model; Figure 5 is Figure 4 a partial enlarged view of

[0030] In Figure 3 the first embodiment shown, the annular protrusion a is provided on the end wall of the valve needle 11 facing the seal 12.

[0031] In Figure 4 and Figure 5 the second embodiment shown, the annular protrusion a is provided on the end wall of the seal 12 facing the valve needle 11.

[0032] In practice, it is also feasible to simultaneously provide the annular protrusion a on the opposite end walls of the valve needle 11 and the seal 12, and the annular protrusions a can be radially spaced apart to achieve multi-layer sealing and improve the sealing effect.

[0033] As described above, the hardness of the seal 12 is lower than that of the valve port part A. The valve port part A is preferably made of a metal material, and the seal 12 is preferably made of a relatively low-hardness polymer material or rubber, etc.

[0034] Further, in this embodiment, the valve needle assembly 1 further includes an elastic member 14, and the elastic member 14 is press-fitted between the valve needle 11 and the seal 12.

[0035] In this way, the elastic member 14 can function to limit the position of the seal member 12 and reduce the up-and-down movement of the seal member 12. During the valve closing process, the seal member 12 will first abut against the valve port portion A, and then, by continuously applying a driving force, the seal member 12 will approach the valve needle 11 axially and gradually compress the elastic member 14 until the valve needle 11 and the seal member 12 are in sealing contact through the annular protrusion a. At this time, the elastic member 14 is in a compressed energy storage state; during the valve opening process, under the action of the restoring force of the elastic member 14, the seal member 12 will first move axially away from the valve needle 11, and the annular protrusion a will disengage from the seal member 12. Then, the entire valve needle assembly 1 is subjected to an upward driving force to achieve the valve opening action.

[0036] In this embodiment, the elastic member 14 is a helical spring. In practical applications, the structural form of the elastic member 14 is not limited. For example, the elastic member 14 can also be a cylindrical structure made of an elastic material such as rubber.

[0037] In practice, the installation position of the elastic member 14 is also not limited. For example, in Figure 3 and Figure 5 shown in the first embodiment and the second embodiment, the elastic member 14 is located radially outside the annular protrusion a; in Figure 6 and Figure 7 shown in the third embodiment, the elastic member 14 is located radially inside the annular protrusion a.

[0038] Compared with the elastic member 14 being installed radially outside the annular protrusion a, installing the elastic member 14 radially inside the annular protrusion a can reduce the size of the elastic member 14, reduce the cost of the elastic member 14, and reduce the processing difficulty of the elastic member 14.

[0039] Furthermore, in some embodiments of the present application, in the end walls of the valve needle 11 and the seal member 12 facing each other, at least one is provided with a mounting portion, and a part of the elastic member 14 is installed inside the mounting portion. In this way, the mounting portion can play a role in positioning the elastic member 14 and ensure the installation stability of the elastic member 14.

[0040] Specifically, as Figure 3 shown, in the first embodiment, the seal member 12 includes an axially connected first diameter section and a second diameter section. The first diameter section is closer to the valve needle 11 than the second diameter section. The diameter of the first diameter section is smaller than that of the second diameter section. A contact portion is formed between the first diameter section and the second diameter section. A part of the elastic member 14 is sleeved on the outer periphery of the first diameter section. One end of the elastic member 14 abuts against the contact portion, and the other end of the elastic member 14 abuts against the end wall of the valve needle 11 facing it. The elastic member 14 is located radially outside the annular protrusion a, and the area between the first diameter section and the second diameter section forms at least part of the area of the mounting portion.

[0041] Thus, the first diameter segment functions to fix the elastic component 14. An interference fit can be adopted between the elastic component 14 and the first diameter segment to ensure the stable installation of the elastic component 14.

[0042] In practical applications, it is also feasible that the valve needle 11 includes an axially connected first diameter segment and second diameter segment. At this time, the first diameter segment is closer to the seal 12 than the second diameter segment. The diameter of the first diameter segment is smaller than that of the second diameter segment. An abutting portion is formed between the first diameter segment and the second diameter segment. The elastic component 14 is partially sleeved on the outer periphery of the first diameter segment. One end of the elastic component 14 abuts against the abutting portion, and the other end of the elastic component 14 abuts against the opposite end wall of the seal 12. The elastic component 14 is located radially outside the annular protrusion a. The region between the first diameter segment and the second diameter segment forms at least part of the installation portion.

[0043] Alternatively, both the valve needle 11 and the seal 12 include an axially connected first diameter segment and second diameter segment. At this time, the diameter of the first diameter segment is smaller than that of the second diameter segment. An abutting portion is formed between the first diameter segment and the second diameter segment. The elastic component 14 is partially sleeved on the outer periphery of the first diameter segment. Both ends of the elastic component 14 abut against the corresponding abutting portions respectively. The elastic component 14 is located radially outside the annular protrusion a. The region between the first diameter segment and the second diameter segment forms at least part of the installation portion.

[0044] In summary, in practice, at least one of the valve needle 11 and the seal 12 includes an axially connected first diameter segment and second diameter segment, and at least one end of the elastic component 14 abuts against the abutting portion.

[0045] Furthermore, as Figure 3 and Figure 5 shown, in some embodiments, the outer contour line of the annular protrusion a coincides with the outer contour line of the first diameter segment in the axial projection plane. The outer peripheral wall of the annular protrusion a and the outer peripheral wall of the first diameter segment are both in fit with the inner contour of the elastic component 14.

[0046] Thus, the annular protrusion a can also play a role in positioning and guiding the elastic component 14, further ensuring the stable installation of the elastic component 14.

[0047] As Figure 6 and Figure 7 shown, in the third embodiment, an annular installation groove is provided on the end wall of the seal 12 facing the valve needle 11. The annular installation groove is located radially inside the annular protrusion a. This annular installation groove forms the installation portion. The elastic component 14 is partially installed in this annular installation groove and abuts against the opposite end wall of the valve needle 11. The elastic component 14 is located radially inside the annular protrusion a.

[0048] In practical applications, the annular mounting groove can be provided not only on the end wall of the seal 12 facing the valve needle 11, but also on the end wall of the valve needle 11 facing the seal 12, or it is also feasible to provide annular mounting grooves corresponding to the opposite end walls of the valve needle 11 and the seal 12.

[0049] It can be understood that in practice, it is also feasible not to provide the aforementioned mounting portion on the opposite end walls of the valve needle 11 and the seal 12, which does not affect the realization of the technical effect of the elastic member 14. Of course, in this embodiment, setting the mounting portion can improve the mounting stability of the elastic member 14, which is a more preferred technical solution.

[0050] In practice, the elastic member 14 can be movably installed inside the mounting portion, that is, there is no connection relationship between the axial two ends of the elastic member 14 and the seal 12 and the valve needle 11. In practical applications, the axial two ends of the elastic member 14 can also be fixedly connected to the seal 12 and the valve needle 11 correspondingly, that is, the elastic member 14 also serves to connect the seal 12 and the valve needle 11.

[0051] In this embodiment, the outer contour line of the annular protrusion a coincides with the sealing loop formed by the seal 12 and the valve port A in the axial projection plane in the closed valve state. In this way, the upper and lower contact diameters of the seal 12 are quite the same, and overall pressure balance can be achieved, improving the operating performance of the valve needle assembly 1.

[0052] As described above, the seal 12 is connected to one end of the valve needle 11 close to the valve port A. Specifically, Figure 3 Understood, the valve needle assembly 1 further includes a connecting sleeve 13. The connecting sleeve 13 is connected to one end of the valve needle 11 close to the valve port A. The connecting sleeve 13 has an installation space inside. The seal 12 is partially installed inside the connecting sleeve 13 and can move axially inside the connecting sleeve 13.

[0053] With the above settings, on the one hand, the connecting sleeve 13 serves to connect the valve needle 11 and the seal 12; on the other hand, the diameter of the second diameter section of the seal 12 is approximately equal to the inner diameter of the connecting sleeve 13. The connecting sleeve 13 serves to guide the seal 12, so that the seal 12 can only move axially along the connecting sleeve 13, ensuring the position accuracy of the seal 12.

[0054] Among them, the valve needle 11 specifically includes a large-diameter section and a small-diameter section connected axially. The small-diameter section is located at one end close to the valve port A. An abutting wall is formed between the large-diameter section and the small-diameter section. The connecting sleeve 13 is fixedly sleeved on the small-diameter section and abuts against the abutting wall; the fixing method of the connecting sleeve 13 and the small-diameter section is not limited. For example, interference fit, welding fixation, threaded connection, etc. can be used to ensure the reliable connection between the connecting sleeve 13 and the valve needle 11.

[0055] One end of the connecting sleeve 13 away from the valve needle 11 is folded inwards, and the folded edge forms a limiting portion 131. The portion of the seal 12 installed inside the connecting sleeve 13 has an abutting wall, and the abutting wall can abut against the limiting portion 131 to limit the axial movement distance of the seal 12 and prevent the seal 12 from coming out of the inside of the connecting sleeve 13.

[0056] In addition, as Figure 3 and Figure 5 shown, in some embodiments of the present application, the outer diameter of the elastic member 14 is approximately equal to the inner diameter of the connecting sleeve 13, and the outer contour of the elastic member 14 fits against the inner wall of the connecting sleeve 13. In this way, an installation portion is formed between the outer wall of the first diameter section of the seal 12 and the inner wall of the connecting sleeve 13, and the outer wall of the first diameter section of the seal 12 and the inner wall of the connecting sleeve 13 can play a role in limiting the elastic member 14, so that the elastic member 14 can only be axially stretched or compressed under force, reducing the possibility of other actions of the elastic member 14 except axial stretching or compression.

[0057] The above has introduced in detail an electronic expansion valve provided by the present utility model. Specific examples are used herein to elaborate on the principle and implementation manner of the present utility model. The description of the above embodiments is only used to help understand the method and its core idea of the present utility model. It should be noted that for those of ordinary skill in the art of this technology, without departing from the principle of the present utility model, several improvements and modifications can be made to the present utility model, and these improvements and modifications also fall within the protection scope of the claims of the present utility model.

Claims

1. An electronic expansion valve, characterized in that, It includes a valve port part (A) provided with a valve port, and a valve needle assembly (1). The valve needle assembly (1) includes a valve needle (11) and a seal (12). The seal (12) is connected to one end of the valve needle (11) close to the valve port part (A). The seal (12) can axially move a preset distance relative to the valve needle (11). At least one of the opposite end walls of the valve needle (11) and the seal (12) is provided with an annular protrusion (a). In the valve-closed state, the seal (12) abuts and seals against the valve port part (A), and the valve needle (11) and the seal (12) abut and seal through the annular protrusion (a). The hardness of the seal (12) is lower than that of the valve port part (A).

2. The electronic expansion valve according to claim 1, characterized in that, The valve needle assembly (1) further includes an elastic member (14), and the elastic member (14) is press-fitted between the valve needle (11) and the seal (12).

3. The electronic expansion valve according to claim 2, characterized in that, The elastic member (14) is located radially inside or outside the annular protrusion (a).

4. The electronic expansion valve according to claim 2, wherein, At least one of the opposite end walls of the valve needle (11) and the seal (12) is provided with a mounting part, and the elastic member (14) is partially mounted inside the mounting part.

5. The electronic expansion valve according to claim 4, characterized in that At least one of the valve needle (11) and the seal (12) includes a first diameter section and a second diameter section axially connected. The diameter of the first diameter section is smaller than that of the second diameter section. An abutting part is formed between the first diameter section and the second diameter section. The elastic member (14) is partially sleeved on the outer periphery of the first diameter section. At least one end of the elastic member (14) abuts against the abutting part. The area between the first diameter section and the second diameter section forms at least part of the area of the mounting part.

6. The electronic expansion valve according to claim 5, characterized in that The outer contour line of the annular protrusion (a) coincides with the outer contour line of the first diameter section in the axial projection plane. The outer peripheral wall of the annular protrusion (a) and the outer peripheral wall of the first diameter section are both fitted to the inner contour of the elastic member (14).

7. The electronic expansion valve according to claim 4, wherein At least one of the opposite end walls of the valve needle (11) and the seal (12) is provided with an inwardly concave annular mounting groove. The annular mounting groove is located radially inside the annular protrusion (a), and the annular mounting groove forms the mounting part.

8. The electronic expansion valve according to any one of claims 1-7, characterized in that, The outer contour line of the annular protrusion (a) coincides with the sealing loop formed by the seal (12) and the valve port part (A) in the valve-closed state in the axial projection plane.

9. The electronic expansion valve according to any one of claims 1-7, characterized in that, The valve needle assembly (1) further includes a connecting sleeve (13). The connecting sleeve (13) is connected to one end of the valve needle (11) close to the valve port part (A). The connecting sleeve (13) has a mounting space inside. The seal (12) is partially mounted inside the connecting sleeve (13) and can axially move a preset distance.

10. The electronic expansion valve according to claim 9, wherein, One end of the connecting sleeve (13) away from the valve needle (11) is turned inward, and this turned edge forms a limiting part (131). The part of the seal (12) mounted inside the connecting sleeve (13) has an abutting wall, and the abutting wall can abut against the limiting part (131).

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