Electronic expansion valve

Abstract

The present application relates to a kind of electronic expansion valves, it includes valve seat, nut component and screw stem valve needle assembly, valve seat is fixedly connected with nut component, valve seat includes valve port and guide portion, screw stem valve needle assembly includes screw stem and valve needle, screw stem and valve needle are limit connection or fixed connection, valve needle and guide portion sliding fit, part screw stem thread cooperation in nut component, by thread cooperation, screw stem valve needle assembly can be axially lifted to move to approach or away from valve port;Valve seat is equipped with first stop portion, valve needle screw stem assembly is equipped with second stop portion, when first stop portion and second stop portion are abutted, the gap between the end sealing surface of valve needle and valve port;Or nut component is equipped with first stop portion, valve needle screw stem assembly is equipped with second stop portion, when first stop portion and second stop portion are abutted, the gap between the end sealing surface of valve needle and valve port;It has small flow while its overall structure is relatively simple in full-closed state.

Description

Technical Field

[0001] This invention relates to the field of refrigeration control technology, specifically to an electronic expansion valve. Background Technology

[0002] The electronic expansion valve includes a valve seat, a nut assembly, a valve needle, and a lead screw. The valve seat has a valve port, the valve needle is adapted to the valve port, the valve seat and the nut assembly are fixed relative to each other, and the lead screw can rotate relative to the nut assembly and drive the valve needle to move along its axial direction to adjust the opening of the valve port.

[0003] Depending on system or customer requirements, a small flow rate adjustment is still needed even when the electronic expansion valve is fully closed. Summary of the Invention

[0004] The purpose of this invention is to provide a novel electronic expansion valve that has a small flow rate in the fully closed state while having a relatively simple overall structure.

[0005] To solve the above-mentioned technical problems, the present invention provides an electronic expansion valve, which includes a valve seat, a nut component, and a screw-valve-needle assembly. The valve seat is fixedly connected to the nut component. The valve seat includes a valve port and a guide portion. The screw-valve-needle assembly includes a screw and a valve needle. The screw and the valve needle are limited or fixedly connected. The valve needle is slidably engaged with the guide portion. A portion of the screw is located within the nut component. The screw and the nut component are threadedly engaged. Through the threaded engagement, the screw-valve-needle assembly can perform axial lifting and lowering movement to approach or move away from the valve port. The valve seat has a protrusion. The protrusion is provided with a guide hole, the inner wall of the guide hole forms the guide portion, the upper end face of the protrusion forms a first stop portion, the valve needle screw assembly is provided with a second stop portion, when the first stop portion abuts against the second stop portion, a gap is left between the end sealing surface of the valve needle and the valve port portion; or the nut component is provided with a first stop portion, the first stop portion protrudes approximately radially towards the axis of the nut component, the valve needle screw assembly is provided with a second stop portion, when the first stop portion abuts against the second stop portion, a gap is left between the end sealing surface of the valve needle and the valve port portion.

[0006] When the first and second stop parts are in contact, the electronic expansion valve is in the fully closed state, and a gap remains between the sealing surface of the valve needle end and the valve port, allowing the electronic expansion valve to still have flow. The first stop part can be located on the valve seat or on the nut assembly, and the second stop part is located on the valve needle screw assembly. The two stop parts (the first and second stop parts) limit the movement of the valve needle screw assembly, ensuring that the electronic expansion valve still has flow even in the fully closed state. The overall structure is relatively simple, and the contact between the two stop parts ensures the flow accuracy in the fully closed state, thus meeting user requirements. Attached Figure Description

[0007] Figure 1 This is a schematic diagram of the structure of an electronic expansion valve provided in an embodiment of the present invention;

[0008] Figure 2 yes Figure 1 Enlarged view of A in the middle;

[0009] Figure 3 This is a schematic diagram of the valve port and end sealing surface in the fully closed state;

[0010] Figure 4 This is a structural diagram of the valve seat and the protrusion;

[0011] Figure 5 This is a structural schematic diagram of the nut component;

[0012] Figures 6-7 This is a schematic diagram of the action component;

[0013] Figures 8-12 These are schematic diagrams of electronic expansion valves with different first and second stop portions.

[0014] Appendix Figure 1-12 The reference numerals in the attached figures are explained as follows:

[0015] 1-Valve seat, 11-Valve port;

[0016] 2-Nut component, 21-Large diameter section, 22-Small diameter section;

[0017] 3-Valve needle, 31-End sealing surface, 32-Limiting protrusion;

[0018] 4-Lead screw;

[0019] 5-First stop part;

[0020] 6-Second stop part;

[0021] 7-Protrusion, 71-Guide hole, 72-Guide part;

[0022] 8-Connector, 81-Cylinder, 82-First flange, 83-Second flange;

[0023] 9-Gap;

[0024] L1 - First distance; L2 - Second distance; D1 - Diameter of valve port; D2 - Diameter of end sealing surface. Detailed Implementation

[0025] To enable those skilled in the art to better understand the technical solutions of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0026] This invention provides an electronic expansion valve, such as... Figure 1 As shown, the electronic expansion valve includes a valve seat 1, a nut component 2, and a screw valve stem assembly. The valve seat 1 is fixedly connected to the nut component 2. The valve seat 1 includes a valve port 11 and a guide portion 72. The screw valve stem assembly includes a screw 4 and a valve needle 3. The screw 4 and the valve needle 3 are either limited or fixedly connected. A fixed connection means that the screw 4 and the valve needle 3 are relatively fixed, while a limited connection means that the screw 4 and the valve needle 3 cannot move relative to each other in the axial direction, but they can rotate relative to each other. The valve needle 3 is slidably engaged with the guide portion 72. Part of the screw 4 is located inside the nut component 2. The screw 4 and the nut component 2 are threadedly engaged. Through the threaded engagement, the screw valve stem assembly can move axially up and down to approach or move away from the valve port 11, thereby adjusting the opening degree of the valve port 11.

[0027] Specifically, when the lead screw 4 rotates relative to the nut component 2, it can drive the valve needle 3 to move relative to the valve seat 1 along the axial direction of the lead screw 4 to the fully closed state (e.g., Figure 2 As shown), a gap 9 remains between the end sealing surface 31 of the valve needle 3 and the valve port 11 (as shown). Figure 3 As shown in the figure, the end sealing surface 31 does not seal the valve port 11, and the electronic expansion valve can still have flow.

[0028] Specifically, the following solutions are provided: The first solution involves a protrusion 7 on the valve seat 1, with a guide hole 71 on the protrusion 7. The inner wall of the guide hole 71 forms the aforementioned guide portion 72. The upper end face of the protrusion 7 forms a first stop portion 5. The valve needle screw assembly has a second stop portion 6. When the screw 4 rotates relative to the nut component 2 and drives the valve needle screw assembly to abut against the first stop portion 5 and the second stop portion 6, the electronic expansion valve is in a fully closed state. A gap 9 remains between the end sealing surface 31 of the valve needle 3 and the valve port 11. The electronic expansion valve still... The first option is to provide flow; the second option is to provide a first stop 5 for the nut component 2, which protrudes approximately radially toward the axis of the nut component 2 (i.e., protrudes radially inward along the nut component 2), and a second stop 6 for the valve needle screw assembly. When the screw 4 rotates relative to the nut component 2 and drives the valve needle screw assembly to abut against the first stop 5 and the second stop 6, the electronic expansion valve is in a fully closed state, and a gap 9 is left between the end sealing surface 31 of the valve needle 3 and the valve port 11, so the electronic expansion valve can still provide flow.

[0029] In other words, the first stop part 5 can be set on the valve seat 1 or the nut component 2, and the second stop part 6 is set on the valve needle screw assembly. By setting the two stop parts (the first stop part 5 and the second stop part 6), the movement of the valve needle screw assembly is limited, so that the electronic expansion valve can still have flow even when it is fully closed. The overall structure is relatively simple, and the flow accuracy in the fully closed state can be guaranteed by the abutting cooperation of the two stop parts, so as to meet the user's needs.

[0030] Furthermore, the diameter D1 of the end sealing surface 31 is not greater than the diameter D2 of the valve port 11. Simultaneously, the axial distance between the first stop portion 5 and the valve port 11 is a first distance L1, and the axial distance between the second stop portion 6 and the end sealing surface 31 is a second distance L2. The first distance L1 is not less than the second distance L2. This arrangement ensures that even in the fully closed state, there is still a gap 9 between the end sealing surface 31 and the valve port 11, allowing the electronic expansion valve to still have flow.

[0031] In this embodiment, there are no restrictions on the specific structure and position of the first stop part 5 and the second stop part 6. As long as the electronic expansion valve is in a fully closed state when the first stop part 5 and the second stop part 6 are in contact, and there is a gap 9 between the end sealing surface 31 and the valve port 11, it is acceptable.

[0032] Specifically, for the first stop portion 5 mentioned above, this embodiment provides the following three configuration methods:

[0033] The first type, such as Figure 2 As shown, the upper end face of the protrusion 7 forms the first stop portion 5, and the axial distance from the upper end face of the protrusion 7 to the valve port portion 11 is the first distance L1.

[0034] The second type, such as Figure 5 As shown, the nut component 2 includes a large diameter section 21 and a small diameter section 22, wherein the inner diameter of the large diameter section 21 is larger than the inner diameter of the small diameter section 22, and the large diameter section 21 can be threaded with the lead screw 4. The small diameter section 22 is located on the side of the large diameter section facing the valve seat 1. The inner wall of the small diameter section 22 forms the first stop portion 5 on the side end face of the large diameter section 21 (i.e., the upper end face of the small diameter section 22). The axial distance from the upper end face of the small diameter section 22 to the valve port portion 11 is the first distance L1.

[0035] The third type is provided with a limiting member on the inner wall of the nut component 2. The upper end face of the limiting member forms the first stop portion 5 mentioned above. The axial distance from the upper end face of the limiting member to the valve port portion 11 is the first distance L1.

[0036] Fourthly, the end of the nut component 2 facing the valve seat 1 is also provided with a connecting part 8, specifically, as shown in the example. Figure 11 and Figure 12 As shown, the connector 8 includes a cylindrical body 81, which is sleeved on the bottom of the nut component 2. The bottom end of the cylindrical body 81 is provided with a first flange 82 in the radial direction. The upper end face of the first flange 82 forms a first stop portion 5. The axial distance from the upper end face of the first flange 82 to the valve port portion 11 is a first distance L1.

[0037] For the second stop portion 6 mentioned above, this embodiment provides the following two configuration methods:

[0038] The first type, such as Figure 6 As shown, a limiting protrusion 32 is provided circumferentially on the outer wall of the side end of the valve needle 3 facing the screw 4. The lower end face of the limiting protrusion 32 forms the second stop portion 6 mentioned above. The axial distance from the lower end face of the limiting protrusion 32 to the end sealing surface 31 is the second distance L2.

[0039] The second type, such as Figure 7 As shown, the diameter of the lead screw 4 is larger than the diameter of the valve needle 3, and the lower end face of the lead screw 4 forms the aforementioned second stop portion 6. The axial distance from the lower end face of the lead screw 4 to the end sealing surface 31 is the second distance L2.

[0040] Any of the four ways of setting the first stop part 5 described above can be combined with any of the two ways of setting the second stop part 6 described above. No specific restrictions are imposed here. The following is a detailed explanation of several combinations.

[0041] like Figure 2As shown, the upper end face of the protrusion 7 forms the first stop portion 5, and the lower end face of the limiting protrusion 32 forms the second stop portion 6. When the lead screw 4 rotates relative to the nut component 2 and drives the valve needle 3 to move along its axial direction until the lower end face of the limiting protrusion 32 abuts against the upper end face of the limiting hole 71, the electronic expansion valve is in the fully closed state, and a gap 9 is left between the end sealing surface 31 and the valve port portion 11.

[0042] like Figure 8 As shown, the upper end face of the protrusion 7 forms the first stop portion 5, and the lower end face of the lead screw 4 forms the second stop portion 6. When the lead screw 4 rotates relative to the nut component 2 and drives the valve needle 3 to move along its axial direction until the lower end face of the lead screw 4 abuts against the upper end face of the limiting hole 71, the electronic expansion valve is in the fully closed state, and a gap 9 is left between the end sealing surface 31 and the valve port portion 11.

[0043] Specifically, in this embodiment, the upper end surface of the protrusion 7 can directly form the first stop portion 5, or the upper end surface of the protrusion 7 can also be provided with an abutting member for abutting against the second stop portion 6. The abutting member can form the first stop structure 5, and no specific limitation is made here.

[0044] like Figure 9 As shown, the nut component 2 includes a large diameter section 21 and a small diameter section 22. The upper end face of the small diameter section 22 forms the first stop portion 5, and the lower end face of the limiting protrusion 32 forms the second stop portion 6. When the screw 4 rotates relative to the nut component 2 and drives the valve needle 3 to move along its axial direction until the lower end face of the limiting protrusion 32 abuts against the upper end face of the small diameter section 22, the electronic expansion valve is in the fully closed state, and a gap 9 is left between the end sealing surface 31 and the valve port portion 11.

[0045] like Figure 10 As shown, the nut component 2 includes a large diameter section 21 and a small diameter section 22. The upper end face of the small diameter section 22 forms the first stop portion 5, and the lower end face of the lead screw 4 forms the second stop portion 6. When the lead screw 4 rotates relative to the nut component 2 and drives the valve needle 3 to move along its axial direction until the lower end face of the lead screw 4 abuts against the upper end face of the small diameter section 22, the electronic expansion valve is in the fully closed state, and a gap 9 is left between the end sealing surface 31 and the valve port portion 11.

[0046] The upper end face of the limiting member forms the first stop portion 5, and the lower end face of the limiting protrusion 32 forms the aforementioned second stop portion 6. When the lead screw 4 rotates relative to the nut component 2 and drives the valve needle 3 to move along its axial direction until the lower end face of the limiting protrusion 32 abuts against the upper end face of the limiting member, the electronic expansion valve is in the fully closed state, and a gap 9 is left between the end sealing surface 31 and the valve port portion 11.

[0047] The upper end face of the limiting member forms a first stop portion 5, and the lower end face of the lead screw 4 forms a second stop portion 6. When the lead screw 4 rotates relative to the nut component 2 and drives the valve needle 3 to move along its axial direction until the lower end face of the lead screw 4 abuts against the upper end face of the limiting member, the electronic expansion valve is in a fully closed state, and a gap 9 is left between the end sealing surface 31 and the valve port portion 11.

[0048] Specifically, in this embodiment, the specific structure of the limiting member provided in the nut component 2 is not limited. It can be set as multiple limiting blocks spaced apart along the inner wall of the nut component 2, or it can be set as a ring structure continuously arranged along the inner wall of the nut component 2.

[0049] like Figure 11 As shown, the upper end face of the first flange 82 of the connector 8 forms the first stop portion 5, and the lower end face of the limiting protrusion 32 forms the second stop portion 6. When the lead screw 4 rotates relative to the nut component 2 and drives the valve needle 3 to move along its axial direction until the lower end face of the limiting protrusion 32 abuts against the upper end face of the first flange 82, the electronic expansion valve is in the fully closed state, and a gap 9 is left between the end sealing surface 31 and the valve port portion 11.

[0050] like Figure 12 As shown, the upper end face of the first flange 82 of the connector 8 forms the first stop portion 5, and the lower end face of the lead screw 4 forms the second stop portion 6. When the lead screw 4 rotates relative to the nut component 2 and drives the valve needle 3 to move along its axial direction until the lower end face of the lead screw 4 abuts against the upper end face of the first flange 82, the electronic expansion valve is in the fully closed state, and a gap 9 is left between the end sealing surface 31 and the valve port portion 11.

[0051] Furthermore, such as Figure 12 As shown, a second flange 83 is provided radially outward at the end of the cylinder 81 away from the first flange 82. This second flange 83 is clamped and fixed between the top of the protrusion 7 and the nut component 2. Specifically, the outer wall of the nut component 2 also has a stepped structure, and the second flange 82 is clamped between the stepped surface of the stepped structure and the top of the protrusion 7. In this embodiment, there are no restrictions on the fixing method between the cylinder 81 and the protrusion 7, or between the cylinder 81 and the nut component 2. The second flange 83 facilitates the fixing operation, such as by welding. Alternatively, the inner wall of the cylinder 81 can be fixed to the outer wall of the nut component 2 by an interference fit, and the outer wall of the cylinder 81 can be fixed to the protrusion 7 by an interference fit or welding.

[0052] Specifically, both the first flange 82 and the second flange 83 are annular structures continuously arranged along the circumference of the cylinder 81. Of course, the first flange 82 can also be set as including at least two block structures spaced apart along the circumference of the cylinder 81, or the second flange 83 can be set as including at least two block structures spaced apart along the circumference of the cylinder 81, or both the first flange 82 and the second flange 83 can be block structures. No specific restrictions are made here. When both the first flange 82 and the second flange 83 are set as annular structures, it can ensure stable installation under force and the overall structure is more regular.

[0053] In the above embodiments, the specific structure of the limiting protrusion 32 provided on the outer wall of the valve needle 3 is not limited. In this embodiment, the limiting structure is set as an annular structure arranged around the circumference of the valve needle 3. Of course, it can also be set as at least two protrusions arranged at intervals along the valve needle 3. The annular protrusion structure is easy to process and can ensure the stability of the fit between the two stop parts.

[0054] The above are merely preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. An electronic expansion valve, characterized in that, The device includes a valve seat (1), a nut component (2), and a screw valve needle assembly. The valve seat (1) is fixedly connected to the nut component (2). The valve seat (1) includes a valve port (11) and a guide portion (72). The screw valve needle assembly includes a screw (4) and a valve needle (3). The screw (4) and the valve needle (3) are axially limited and can rotate relative to each other. The valve needle (3) is slidably engaged with the guide portion (72). Part of the screw (4) is located inside the nut component (2). The screw (4) and the nut component (2) are threadedly engaged. Through the threaded engagement, the screw valve needle assembly can perform axial lifting and lowering movements to approach or move away from the valve port (11). The valve seat (1) is provided with a protrusion (7), the protrusion (7) is provided with a guide hole (71), and the inner wall of the guide hole (71) forms the guide portion (72). The nut component (2) is provided with a first stop part (5), which protrudes approximately radially toward the axis of the nut component (2). The screw valve needle assembly is provided with a second stop part (6). When the first stop part (5) abuts against the second stop part (6), a gap is left between the end sealing surface (31) of the valve needle (3) and the valve port (11). The outer wall of the valve needle (3) is provided with a limiting protrusion (32) along the circumferential direction. The screw (4) can drive the valve needle (3) to move along its axial direction until the limiting protrusion (32) abuts against the first stop part (5). The lower end face of the limiting protrusion (32) forms the second stop part (6). The limiting protrusion (32) is an annular structure arranged circumferentially along the outer wall of the valve needle (3); The first stop part (5) is provided at the bottom end of the nut component (2); The nut component (2) is further provided with a connector (8) at one end facing the valve seat (1). The connector (8) includes a cylindrical body (81) sleeved outside the bottom of the nut component (2). The bottom end of the cylindrical body (81) is provided with a first flange (82) inward along its radial direction. The upper end face of the first flange (82) forms the first stop portion (5). The first flange (82) is an annular structure continuously arranged along the circumference of the cylindrical body (81). The top of the cylinder (81) is provided with a second flange (83) extending radially outward, and the second flange (83) is clamped and fixed between the top of the protrusion (7) and the nut component (2).

2. The electronic expansion valve according to claim 1, characterized in that, The diameter (D2) of the end sealing surface is not greater than the diameter (D1) of the valve port. The axial distance between the first stop part (5) and the valve port part (11) is the first distance (L1), and the axial distance between the second stop part (6) and the end sealing surface (31) is the second distance (L2). The first distance (L1) is not less than the second distance (L2).

3. The electronic expansion valve according to claim 1 or 2, characterized in that, The second flange (83) is an annular structure arranged circumferentially along the cylinder (81).

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