Electronic Expansion Valve

Abstract

It includes a valve seat portion (10), a gasket (20), and a valve head (30). The valve seat portion (10) has a valve chamber (11) and a first flow path (12). The gasket (20) is located within the valve seat portion (10) and is in sealing engagement with the valve seat portion (10). The gasket (20) is provided surrounding the first flow path (12). The gasket (20) has a second flow path (21). The first flow path (12) and the second flow path (21) are in communication. The valve head (30) is movably provided within the valve chamber (11) so as to open and close the second flow path (21), and is in communication with the valve chamber (11) when the second flow path (21) is opened. Here, the first flow path (12) and the second flow path (21) constitute a variable flow path. The flow areas at both ends of the variable flow path are S1 and S2 respectively, and the minimum flow area at the middle portion of the variable flow path is S3, where S3 < S1 and S3 < S2. An electronic expansion valve is disclosed. This structure enables the flow velocity to increase when the fluid flows through the variable flow path, effectively improving the flow capacity of the electronic expansion valve, increasing the Cv value, adopting the engagement between the gasket and the valve head to realize the opening and closing of the flow path, reducing the internal leakage of the electronic expansion valve, and ensuring the reliable conduction and cut-off functions of the electronic expansion valve.

Description

[Technical Field]

[0001] This application claims priority to a patent application filed with the State Intellectual Property Office of China on September 20, 2022, bearing application number 202211145110.8 and entitled "Electronic Expansion Valve."

[0002] The present application relates to the technical field of electronic expansion valves, and more particularly to electronic expansion valves. [Background technology]

[0003] Most electronic expansion valves may have internal leakage after being closed. Large-diameter, low-leakage electronic expansion valves are required to have very little internal leakage when closed, be able to conduct and cut off, and have a certain Cv value, which is required to be relatively large. The Cv value represents the element's ability to flow through the liquid, i.e., the flow coefficient, and is also called the Kv value.

[0004] In conventional electronic expansion valves, the flow path is opened and closed by the movement of the valve head, realizing the electronic expansion valve's conduction and cutoff functions. The flow path engaged with the valve head is usually a straight flow path with a fixed flow area. When the valve head opens the flow path, the fluid in the flow path is likely to generate vortices at one end close to the valve head, which affects the flow capacity of the flow path and reduces the Cv value. Therefore, the flow path structure in conventional electronic expansion valves has the problem of poor flow capacity.

[0005] The present application provides an electronic expansion valve to solve the problem of poor flow capacity of the electronic expansion valve in the prior art.

[0006] To solve the above problems, the present application provides an electronic expansion valve including a valve seat portion having a valve chamber and a first flow path, a gasket located within the valve seat portion and engaged with the valve seat portion, provided surrounding the first flow path, having a second flow path, and the first flow path and the second flow path being communicated with each other, and a valve head movably provided within the valve chamber to open and close the second flow path and being communicated with the valve chamber when the second flow path is opened, wherein the hardness of both the valve head and the valve seat portion is higher than the hardness of the gasket. Here, the first flow path and the second flow path constitute a variable flow path, the flow areas at both ends of the variable flow path are S1 and S2 respectively, and the minimum flow area at the middle portion of the variable flow path is S3, and S3 < S1 and S3 < S2.

[0007] Furthermore, the minimum flow area at the middle portion of the variable flow path is located in the first flow path and / or the second flow path.

[0008] Furthermore, the inner surface of the variable flow path is an arc-shaped surface, or the inner surface of the variable flow path includes a tapered surface of a plurality of segments.

[0009] Furthermore, in the direction of the valve chamber of the first flow path, the inner surface of the second flow path includes a first annular surface, a second annular surface, and a third annular surface connected in sequence. The first annular surface is a cylindrical surface or a tapered surface, the second annular surface is a tapered surface, and the third annular surface is a cylindrical surface or a tapered surface. Here, the larger end of the opening of the tapered surface in the second flow path faces the valve chamber.

[0010] Furthermore, in a cross-section passing through the axis of the first flow path, the included angle between the first annular surface and the axis of the first flow path is A1, the included angle between the second annular surface and the axis of the first flow path is A2, and the included angle between the third annular surface and the axis of the first flow path is A3, where A1 < A2 < A3.

[0011] Furthermore, 0 ≦ A1 ≦ 10°, 6° ≦ A2 ≦ 26°, 40° ≦ A3 ≦ 60°.

[0012] Furthermore, in the direction of the second flow path toward the first flow path, the inner surface of the first flow path includes a fourth annular surface and a fifth annular surface connected in sequence, the fourth annular surface being a cylindrical surface or a tapered surface, and the fifth annular surface being a tapered surface, wherein one end of the larger opening of the tapered surface in the first flow path is away from the valve chamber.

[0013] Furthermore, in a cross section passing through the axis of the second flow passage, the included angle between the fourth annular surface and the axis of the second flow passage is B1, the included angle between the fifth annular surface and the axis of the second flow passage is B2, and B1 <B2である。

[0014] Furthermore, 0≦B1≦10°, and 2°≦B2≦25°.

[0015] Furthermore, the gasket has an annular sealing surface on one side facing the valve chamber, the annular sealing surface is arranged to surround the second flow path, the outer diameter of the valve head is larger than the inner diameter of the second flow path, and when the valve head and the annular sealing surface abut against each other, the valve head closes the second flow path.

[0016] Furthermore, the valve seat portion includes a main valve seat and a sub-valve seat connected to each other, the main valve seat having a valve chamber, the sub-valve seat having a first flow path, the sub-valve seat further having an annular groove, and the gasket is installed in the annular groove.

[0017] Further, the sub-valve seat includes a main body and an annular cylinder attached to the main body, the main body having a first flow path, the annular cylinder having an annular groove, the main body being fixedly connected to the main valve seat, and one end of the annular cylinder remote from the main body being crimped to a gasket, the electronic expansion valve further includes a first connecting pipe and a second connecting pipe, the first connecting pipe being connected to the main valve seat and communicating with the valve chamber, and the second connecting pipe being connected to the main body and communicating with the first flow path, and the fluid areas of the first connecting pipe and the second connecting pipe are both greater than S3.

[0018] Furthermore, one side of the gasket facing the valve chamber has a first annular chamfer, the first annular chamfer is provided to surround the outside of the annular sealing surface, one side of the gasket facing the sub-valve seat has a second annular chamfer, the second annular chamfer is provided to surround the second flow path, and one side of the sub-valve seat facing the gasket has a third annular chamfer, the third annular chamfer is provided to surround the first flow path.

[0019] When applying the technical solution of the present application, it includes a valve seat portion, a gasket and a valve head. The valve seat portion has a valve chamber and a first flow path. The gasket is located within the valve seat portion and engaged with the valve seat portion. The gasket is provided to surround the first flow path. The gasket has a second flow path. The first flow path and the second flow path are communicated. The valve head is movably provided within the valve chamber so as to open and close the second flow path, and is communicated with the valve chamber when the second flow path is opened. The hardness of both the valve head and the valve seat portion is higher than that of the gasket. Here, the first flow path and the second flow path constitute a variable flow path. The flow areas at both ends of the variable flow path are S1 and S2 respectively, and the minimum flow area at the middle part of the variable flow path is S3, where S3 < S1 and S3 < S2. An electronic expansion valve is provided. In this aspect, the flow paths in the gasket and the valve seat portion constitute a variable flow path. The minimum flow area at the middle part of the variable flow path is smaller than the flow areas at both ends, that is, the variable flow path has a structure that is narrow in the middle and wide at both ends. Adopting such a structure, compared with a straight flow path, when the fluid flows through the variable flow path, the flow velocity becomes faster. When the flow velocity becomes faster, the formation of vortices near the valve head can be avoided or reduced, so as to avoid or reduce the influence of vortices on the flow capacity. Therefore, this aspect effectively improves the flow capacity of the electronic expansion valve and increases the Cv value. In addition, this aspect adopts the engagement between the gasket and the valve head to realize the opening and closing of the flow path. Compared with the case of adopting a rigid structure, the sealing effect is good, the internal leakage of the electronic expansion valve is reduced, and the reliable conduction and cut-off functions of the electronic expansion valve are ensured.

Brief Description of the Drawings

[0020] The drawings in the specification that form a part of this application are intended to provide a further understanding of the application, and the schematic examples and descriptions thereof are intended to aid in the interpretation of the application and are not intended to unduly limit the application.

[0021] [Figure 1] 1 shows a structural schematic diagram of an electronic expansion valve provided in an embodiment of the present application. [Figure 2] 2 is a schematic diagram showing the assembly of the sub-valve seat and the gasket in FIG. 1. [Figure 3] An enlarged view of a portion of Figure 2 is shown.

[0022] The above drawings include the following reference numerals: 10 valve seat portion, 11 valve chamber, 12 first flow path, 121 fourth annular surface, 122 fifth annular surface, 13 main valve seat, 14 auxiliary valve seat, 141 annular groove, 142 main body, 143 annular cylinder, 20 gasket, 21 second flow path, 211 first annular surface, 212 second annular surface, 213 third annular surface, 22 annular sealing surface, 30 valve head, 41 first connecting pipe, 42 second connecting pipe. DETAILED DESCRIPTION OF THE INVENTION

[0023] Hereinafter, the technical aspects of the embodiments of the present application will be described clearly and completely with reference to the drawings in the embodiments of the present application. However, it is clear that the described embodiments are only some of the embodiments of the present application, and not all of the embodiments. The description of at least one exemplary embodiment below is merely explanatory in nature and does not impose any restrictions on the present application and its application or use. Based on the embodiments of the present application, all other embodiments that can be obtained by those skilled in the art without creative efforts shall fall within the scope of protection of the present application.

[0024] As shown in FIGS. 1 to 3, an embodiment of the present application includes a valve seat portion 10 having a valve chamber 11 and a first flow path 12, and a gasket 20 positioned within the valve seat portion 10 and engaged with the valve seat portion 10. The gasket 20 is provided to surround the first flow path 12. The gasket 20 has a second flow path 21, and the first flow path 12 and the second flow path 21 are in communication with each other. A valve head 30 is movably provided within the valve chamber 11 so as to open and close the second flow path 21. When the second flow path 21 is opened, the valve head 30 is in communication with the valve chamber 11. The hardness of both the valve head 30 and the valve seat portion 10 is higher than that of the gasket 20. Here, the first flow path 12 and the second flow path 21 constitute a variable flow path. The flow areas at both ends of the variable flow path are S1 and S2 respectively, and the minimum flow area at the middle portion of the variable flow path is S3, where S3 < S1 and S3 < S2. An electronic expansion valve is provided. Here, the gasket 20 may be made of a soft material such as rubber, which can provide a good sealing effect.

[0025] In this aspect, the second flow path 21 and the first flow path 12 in the gasket 20 and the valve seat portion 10 constitute a variable flow path. The minimum flow area S3 at the middle portion of the variable flow path is smaller than the flow areas at both ends. That is, the variable flow path has a structure that is narrow in the middle and wide at both ends. By adopting such a structure, compared with a straight flow path, when the fluid flows through the minimum flow area of the variable flow path, the flow velocity increases. When the flow velocity increases, it is possible to avoid or reduce the formation of eddy currents in the vicinity of the valve head 30, thereby avoiding or reducing the influence of eddy currents on the flow capacity. Therefore, this aspect effectively improves the flow capacity of the electronic expansion valve and increases the Cv value. In addition, this aspect adopts the engagement between the gasket 20 and the valve head 30 to achieve the opening and closing of the flow path. Compared with the case of adopting a rigid structure, it has a good sealing effect, reduces the internal leakage of the electronic expansion valve, and ensures the reliable conduction and cutoff functions of the electronic expansion valve. The variable flow path in this aspect utilizes the principle of a Laval nozzle.

[0026] Here, the position of the minimum flow area in the middle part of the variable flow path is located at a position close to the second flow path 21 of the first flow path 12, or at a position close to the first flow path 12 of the second flow path 21, or is simultaneously located at a position where the first flow path 12 and the second flow path 21 are close to each other.

[0027] In this embodiment, the inner surface of the variable diameter flow path may be an arc-shaped surface. In this way, the resistance of the fluid is small and the flow is relatively smooth. For example, the inner surface of the variable diameter flow path is an elliptical surface. Alternatively, the inner surface of the variable flow path includes a tapered surface of a plurality of segments, and adopting a tapered surface of a plurality of segments with a changing diameter can also achieve the effect of changing the diameter and increasing the flow velocity, and such a method can reduce the difficulty of processing.

[0028] As shown in FIGS. 2 and 3, in the direction toward the valve chamber 11 of the first flow path 12, the inner surface of the second flow path 21 includes a first annular surface 211, a second annular surface 212, and a third annular surface 213 that are connected in sequence. The first annular surface 211 is a cylindrical surface or a tapered surface, the second annular surface 212 is a tapered surface, and the third annular surface 213 is a cylindrical surface or a tapered surface. Here, the end with the larger opening of the tapered surface in the second flow path 21 faces the valve chamber 11. In this way, by providing the first annular surface 211, the second annular surface 212, and the third annular surface 213, it is realized that the flow area changes from small to large, and the processing becomes easy.

[0029] In a specific embodiment, in the cross-section passing through the axis of the first flow path 12, the included angle between the first annular surface 211 and the axis of the first flow path 12 is A1, the included angle between the second annular surface 212 and the axis of the first flow path 12 is A2, and the included angle between the third annular surface 213 and the axis of the first flow path 12 is A3, where A1 < A2 < A3. Here, the minimum flow area of the variable flow path is located before the first annular surface 211 or at the first annular surface 211. By providing as described above and making the flow areas of the three annular surfaces gradually smaller to larger, a Laval nozzle is formed.

[0030] Specifically, 0 ≦ A1 ≦ 10°, 6° ≦ A2 ≦ 26°, and 40° ≦ A3 ≦ 60°. When the included angles between the first annular surface 211, the second annular surface 212, the third annular surface 213 and the axis of the first flow path 12 are within the above ranges, the fluid passing through this structure can have a relatively high flow velocity, avoiding or reducing the formation of eddy currents near the valve head 30, and increasing the Cv value of the electronic expansion valve.

[0031] As shown in FIGS. 2 and 3, in the direction of the second flow path 21 towards the first flow path 12, the inner surface of the first flow path 12 includes a fourth annular surface 121 and a fifth annular surface 122 connected in sequence. The fourth annular surface 121 is a cylindrical surface or a tapered surface, and the fifth annular surface 122 is a tapered surface. Here, the end with the larger opening of the tapered surface in the first flow path 12 is away from the valve chamber 11. The fluid enters the valve chamber from the first flow path 12. By providing it as described above, in the process of the fluid flowing in the first flow path 12, there is a process where the flow area changes from large to small. By doing so, when the flow velocity of the fluid increases, the formation of eddy currents when the fluid flows near the valve head 30 is avoided or reduced, and the Cv value of the electronic expansion valve is increased. Here, the fifth annular surface 122 may be a tapered surface composed of a plurality of segments connected in sequence.

[0032] Specifically, in the cross-section passing through the axis of the second flow path 21, the included angle between the fourth annular surface 121 and the axis of the second flow path 21 is B1, the included angle between the fifth annular surface 122 and the axis of the second flow path 21 is B2, and B1 < B2. By doing so, it is advantageous for realizing the change of the flow area and is also easy to process.

[0033] Here, 0 ≦ B1 ≦ 10° and 2° ≦ B2 ≦ 25°. When the included angles between the fourth annular surface 121 and the fifth annular surface 122 and the axis of the second flow path 21 are within the above ranges, the fluid passing through this structure can have a relatively high flow velocity, avoiding or reducing the formation of eddy currents near the valve head 30, and increasing the Cv value of the electronic expansion valve. In this embodiment, the second flow path 21 and the first flow path 12 are provided coaxially.

[0034] As shown in Figures 1 and 2, the gasket 20 has an annular sealing surface 22 on one side facing the valve chamber 11, which surrounds the second flow passage 21. The outer diameter of the valve head 30 is larger than the inner diameter of the second flow passage 21. When the valve head 30 and the annular sealing surface 22 come into contact, the valve head 30 closes the second flow passage 21. The contact between the valve head 30 and the annular sealing surface 22 compresses the gasket 20, increasing the contact area and providing a good sealing effect, resulting in low or no internal leakage after the valve is closed. Compared to the prior art, this embodiment employs a soft-sealing structure for engagement with the valve head 30, and the sealing surface is located on the end face of the gasket 20 rather than on the inner wall of the flow passage. This prevents wear and damage to the inner wall of the flow passage, increases the contact area, and ensures reliable sealing.

[0035] In this embodiment, the valve seat portion 10 may be an integral structure, which provides a relatively high structural strength, or the valve seat portion 10 may be a separate structure, which facilitates processing.

[0036] In a specific embodiment, the valve seat assembly 10 includes a main valve seat 13 and a sub-valve seat 14 connected to each other, the main valve seat 13 having a valve chamber 11, the sub-valve seat 14 having a first flow passage 12, and the sub-valve seat 14 further having an annular groove 141, and the gasket 20 is installed in the annular groove 141. By forming the valve seat assembly 10 into two separate parts, they can be processed separately, and the main valve seat 13 and the sub-valve seat 14 can be connected after the gasket 20 is installed in the annular groove 141, which facilitates assembly.

[0037] Specifically, the sub-valve seat 14 includes a body 142 and an annular tube 143 attached to the body 142, the body 142 having a first passage 12, the annular tube 143 having an annular groove 141, the body 142 fixedly connected to the main valve seat 13, and one end of the annular tube 143 remote from the body 142 crimped to the gasket 20. The electronic expansion valve further includes a first connecting pipe 41 and a second connecting pipe 42, the first connecting pipe 41 connected to the main valve seat 13 and communicating with the valve chamber 11, and the second connecting pipe 42 connected to the body 142 and communicating with the first passage 12, each with a fluid area greater than S3. Using a crimping method to fix the gasket 20 ensures a reliable connection. Here, a portion of the main body 142 penetrates into the main valve seat 13, and the two are restricted in the axial direction by a step structure, and the main body 142 and the main valve seat 13 can be connected by methods such as interference fit or welding.

[0038] Furthermore, the gasket 20 has a first annular chamfer on one side facing the valve chamber 11, the first annular chamfer surrounding the outside of the annular sealing surface 22, a second annular chamfer on one side facing the sub-valve seat 14, the second annular chamfer surrounding the second flow path 21, and a third annular chamfer on one side of the sub-valve seat 14 facing the gasket 20, the third annular chamfer surrounding the first flow path 12. The annular chamfers prevent burrs from being generated during processing and ensure the precision of the electronic expansion valve.

[0039] Alternatively, in one specific embodiment, the valve head 30 is provided with a sealing surface and a flow-directing surface. The sealing surface surrounds the flow-directing surface, i.e., the sealing surface is annular, and the sealing surface is sealingly engaged with the annular sealing surface 22. The flow-directing surface is tapered. The tapered flow-directing surface reduces resistance to fluid flow and improves fluid flow capacity. Furthermore, the valve head 30 is provided with a clearance groove located between the sealing surface and the flow-directing surface. Burrs or localized flanges are inevitably generated during processing of the valve head 30. By providing the clearance groove, the burrs or flanges generated during processing are positioned within the clearance groove, preventing the burrs or localized flanges from affecting the sealing engagement and ensuring effective sealing.

[0040] The above is only a preferred embodiment of the present application, and is not intended to limit the present application. Those skilled in the art can make various modifications and variations to the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present application should be included within the protection scope of the present application.

Claims

1. a valve seat portion (10) having a valve chamber (11) and a first flow path (12); a gasket (20) located within the valve seat (10) and engaged with the valve seat (10), the gasket (20) surrounding the first flow path (12), the gasket (20) having a second flow path (21), and the first flow path (12) and the second flow path (21) communicating with each other; a valve head (30) that is movably provided in the valve chamber (11) to open and close the second flow path (21), and that is in communication with the valve chamber (11) when the second flow path (21) is opened, wherein the hardness of the valve head (30) and the valve seat portion (10) is both higher than the hardness of the gasket (20), Here, the first flow path (12) and the second flow path (21) constitute a variable diameter flow path, the flow areas at both ends of the variable diameter flow path are S1 and S2, respectively, the minimum flow area at the middle part of the variable diameter flow path is S3, and S3<S1 and S3<S2.

2. 2. The electronic expansion valve according to claim 1, wherein the minimum flow area in the middle of the variable diameter flow passage is located in the first flow passage (12) and / or the second flow passage (21).

3. The electronic expansion valve according to claim 1 , wherein the inner surface of the variable diameter passage is an arcuate surface, or the inner surface of the variable diameter passage includes a tapered surface having multiple segments.

4. 2. The electronic expansion valve according to claim 1, wherein, in a direction of the first flow path (12) toward the valve chamber (11), an inner surface of the second flow path (21) includes a first annular surface (211), a second annular surface (212), and a third annular surface (213) connected in this order, the first annular surface (211) being a cylindrical surface or a tapered surface, the second annular surface (212) being a tapered surface, and the third annular surface (213) being a cylindrical surface or a tapered surface, wherein one end of a larger opening of the tapered surface in the second flow path (21) faces toward the valve chamber (11).

5. In a cross section passing through the axis of the first flow path (12), an included angle between the first annular surface (211) and the axis of the first flow path (12) is A1, an included angle between the second annular surface (212) and the axis of the first flow path (12) is A2, and an included angle between the third annular surface (213) and the axis of the first flow path (12) is A3, wherein:

5. The electronic expansion valve according to claim 4, wherein A1<A2<A3.

6. 6. The electronic expansion valve according to claim 5, wherein 0°≦A1≦10°, 6°≦A2≦26°, and 40°≦A3≦60°.

7. 2. The electronic expansion valve according to claim 1, wherein, in a direction of the second flow path (21) toward the first flow path (12), an inner surface of the first flow path (12) includes a fourth annular surface (121) and a fifth annular surface (122) connected in order, the fourth annular surface (121) being a cylindrical surface or a tapered surface, and the fifth annular surface (122) being a tapered surface, wherein one end of a larger opening of the tapered surface in the first flow path (12) is away from the valve chamber (11).

8. 8. The electronic expansion valve according to claim 7, wherein, in a cross section passing through the axis of the second flow passage (21), an included angle between the fourth annular surface (121) and the axis of the second flow passage (21) is B1, an included angle between the fifth annular surface (122) and the axis of the second flow passage (21) is B2, and B1<B2.

9. 2. The electronic expansion valve according to claim 1, wherein 0≦B1≦10° and 2°≦B2≦25°.

10. 2. The electronic expansion valve according to claim 1, wherein the gasket has an annular sealing surface on one side facing the valve chamber, the annular sealing surface surrounding the second flow path, the valve head having an outer diameter larger than an inner diameter of the second flow path, and wherein the valve head closes the second flow path when the valve head and the annular sealing surface come into contact with each other.

11. 11. The electronic expansion valve according to claim 10, wherein the valve seat portion (10) includes a main valve seat (13) and a sub-valve seat (14) connected to each other, the main valve seat (13) having the valve chamber (11), the sub-valve seat (14) having the first flow path (12), the sub-valve seat (14) further having an annular groove (141), and the gasket (20) being mounted in the annular groove (141).

12. The sub-valve seat (14) includes a main body (142) and an annular cylinder (143) provided in the main body (142), the main body (142) has the first flow path (12), the annular cylinder (143) has the annular groove (141), the main body (142) is fixedly connected to the main valve seat (13), one end of the annular cylinder (143) remote from the main body (142) is crimped to the gasket (20), and the electronic expansion valve is 12. The electronic expansion valve according to claim 11, further comprising a connecting pipe (41) and a second connecting pipe (42), wherein the first connecting pipe (41) is connected to the main valve seat (13) and communicates with the valve chamber (11), and the second connecting pipe (42) is connected to the body (142) and communicates with the first flow path (12), and the fluid areas of the first connecting pipe (41) and the second connecting pipe (42) are both greater than S3.

13. 12. The electronic expansion valve according to claim 11, wherein the gasket (20) has a first annular chamfer on one side facing the valve chamber (11), the first annular chamfer surrounding the outside of the annular sealing surface (22); the gasket (20) has a second annular chamfer on one side facing the sub-valve seat (14), the second annular chamfer surrounding the second flow path (21); and the sub-valve seat (14) has a third annular chamfer on one side facing the gasket (20), the third annular chamfer surrounding the first flow path (12).

14. 2. The electronic expansion valve according to claim 1, wherein the valve head (30) has a sealing surface and a flow-directing surface, the sealing surface being annular and surrounding the flow-directing surface, the sealing surface being in sealing engagement with an end face of the gasket (20), and the flow-directing surface being a tapered surface to reduce fluid resistance.

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