CN216200581U

CN216200581U - Electronic expansion valve

Info

Publication number: CN216200581U
Application number: CN202122411352.4U
Authority: CN
Inventors: 詹少军; 陈勇好; 黄鸿峰
Original assignee: Zhejiang DunAn Hetian Metal Co Ltd
Current assignee: Zhejiang DunAn Hetian Metal Co Ltd
Priority date: 2021-09-30
Filing date: 2021-09-30
Publication date: 2022-04-05
Anticipated expiration: 2031-09-30

Abstract

The utility model provides an electronic expansion valve, comprising: the valve body is provided with an accommodating cavity and a valve port, and the accommodating cavity is communicated with the valve port; the rotor assembly is arranged in the accommodating cavity; the stator assembly is sleeved outside the valve body and corresponds to the rotor assembly; the screw assembly is arranged in the accommodating cavity and comprises a screw and a nut sleeve, the nut sleeve is fixed on the valve body, the screw penetrates through the nut sleeve and is in threaded connection with the nut sleeve, and the rotor assembly is fixedly connected with one end of the screw, which is far away from the valve port; the screw is in driving connection with the valve sleeve, and the valve sleeve is used for plugging or opening the valve port; the pulse number is A when the valve port is in a fully open state, the corresponding pulse number is B when the central line of the stator assembly perpendicular to the axis is superposed with the central line of the rotor assembly perpendicular to the axis, and B is not less than 0.3 and not more than 0.7. By adopting the scheme, the problem that the driving force of the electronic expansion valve is weak is solved.

Description

Electronic expansion valve

Technical Field

The utility model relates to the technical field of control valves, in particular to an electronic expansion valve.

Background

The electronic expansion valve comprises a valve body, a rotor assembly, a stator assembly, a screw assembly, a valve sleeve and other components, wherein the valve body is provided with a cavity and a valve port, the rotor assembly is arranged in the cavity, the rotor assembly is connected with the screw assembly, the screw assembly is connected with the valve sleeve, the stator assembly is arranged outside the valve body, the stator assembly and the rotor assembly are correspondingly arranged, the stator assembly and the rotor assembly interact to enable the rotor assembly to drive the screw assembly, and the rotor assembly and the screw assembly do linear motion along the axis of the valve body to drive the valve sleeve to block or open the valve port. Stator module's the winding and the rotor subassembly when just right area is big more, stator module and rotor subassembly's drive power is big more, among the prior art, stator module and rotor subassembly's the general design of position is when the valve port is in the state of closing entirely, rotor subassembly and stator module just to the area maximum, the drive power of rotor subassembly drive screw subassembly motion is the biggest, above-mentioned scheme can make the valve body rotor subassembly when opening entirely and stator module just to the area undersize to lead to the valve barrel to step out or can not close the valve port.

SUMMERY OF THE UTILITY MODEL

The utility model provides an electronic expansion valve, which aims to solve the problem that the driving force of the electronic expansion valve in the prior art is weak in a full-open state.

The utility model provides an electronic expansion valve, comprising: the valve body is provided with an accommodating cavity and a valve port, and the accommodating cavity is communicated with the valve port; the rotor assembly is arranged in the accommodating cavity; the stator assembly is sleeved outside the valve body and corresponds to the rotor assembly; the screw assembly is arranged in the accommodating cavity and comprises a screw and a nut sleeve, the nut sleeve is fixed on the valve body, the screw penetrates through the nut sleeve and is in threaded connection with the nut sleeve, the rotor assembly is fixedly connected with one end of the screw, which is far away from the valve port, and the rotor assembly drives the screw to rotate along the nut sleeve so that the screw and the rotor assembly move along the direction towards or far away from the valve port; the screw is in driving connection with the valve sleeve, and the valve sleeve is used for plugging or opening the valve port; the pulse number is 0 when the valve port is in a fully closed state, the pulse number is A when the valve port is in a fully open state, the corresponding pulse number is B when the central line of the stator assembly perpendicular to the axis is superposed with the central line of the rotor assembly perpendicular to the axis, and B is more than or equal to 0.3 and less than or equal to 0.7. In particular, B may be 0.3 a, 0.4 a, 0.5 a or 0.7 a.

By applying the technical scheme of the utility model, when the central line of the stator component perpendicular to the axis is coincident with the central line of the rotor component perpendicular to the axis, the force for driving the screw rod to rotate by the rotor component is the largest. If the pulse number B is less than 0.3 × a, the driving force of the rotor assembly is the largest when the valve port is close to the fully closed state, i.e., the driving force is weaker and weaker in the process of opening the valve port, so that the valve port is slower or cannot be completely closed. If the pulse number B is larger than 0.7A, the driving force of the rotor assembly is the maximum when the valve port is close to the full-open state, namely the driving force is weaker and weaker in the process of closing the valve port, so that the valve port is slow or can not be opened completely. Therefore, the relation between A and B is set to be 0.3A and B, the B is not less than 0.7A, the driving force of the rotor assembly is maximum when the valve port is in a half-open state, so that the driving force is balanced in the process of opening or closing the valve port, the valve port is opened or closed more reliably, and the valve port can be opened or closed completely.

Further, B ═ 0.5 × a. When B is 0.5A, the driving force of the rotor assembly is maximum when the valve port is in a half-open state, so that the driving force is balanced in the process of opening or closing the valve port, and the valve port is opened or closed more reliably.

Further, the length of the rotor assembly along the axial direction is L1, the stator assembly is provided with an upper pole plate and a lower pole plate which are arranged at intervals along the axial direction, the distance between the upper pole plate and the lower pole plate is L2, and L2 is larger than L1. This enables the maximum driving force to continue to cover the stroke.

Furthermore, L2-L1 is more than or equal to 0.2mm and less than or equal to 1mm. By the arrangement, the stroke can be continuously covered by the maximum driving force, and the electronic expansion valve can be compact in structure.

Furthermore, the outer diameter of the rotor assembly is D1, the inner diameter of the containing cavity is D2, and D2-D1 are more than or equal to 0.3mm and less than or equal to 1mm. Therefore, the friction force between the rotor assembly and the inner wall of the accommodating cavity is small when the rotor assembly rotates, and the driving force is large.

Furthermore, the outer diameter of the valve body is D3, the inner diameter of the stator assembly is D4, and D4-D3 are more than or equal to 0.05mm and less than or equal to 0.5 mm. So set up, can enough guarantee that stator module can more convenient installation on the valve body, can make drive power great again.

Further, D1 is more than or equal to 13mm and less than or equal to 18 mm. Therefore, the driving force can be ensured to be larger, and the structure of the electronic expansion valve can be compact.

Furthermore, L1 is more than or equal to 18mm and less than or equal to 23 mm. Therefore, the driving force can be ensured to be larger, and the length of the electronic expansion valve can be smaller.

Furthermore, a balance channel is arranged in the valve sleeve and can enable the two ends of the valve sleeve to be communicated.

Furthermore, a through hole is arranged in the valve sleeve and comprises first hole sections which are arranged in sequence, the valve comprises a first hole section, a second hole section and a third hole section, the diameters of the first hole section and the third hole section are larger than that of the second hole section, one end of a screw rod, close to a valve port, penetrates through the third hole section, a fixing part is fixedly connected to one end of the screw rod, close to the valve port, the diameter of the fixing part is larger than that of the second hole section, the fixing part is arranged at one end, far away from the valve port, of the third hole section, a connecting hole is formed in the fixing part, the end portion of the screw rod penetrates through the connecting hole, a tangent plane structure is arranged on the side wall of one end, close to the valve port, of the screw rod, extends to the first hole section, a first gap is formed between the tangent plane structure and the inner wall of a through hole, a second gap is formed between the connecting hole and the tangent plane structure, the first gap is communicated with the second gap, and the first gap and the second gap form a balance channel to balance air pressures at two ends of the valve sleeve.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this application, illustrate embodiments of the utility model and, together with the description, serve to explain the utility model and not to limit the utility model. In the drawings:

FIG. 1 is a schematic diagram of an electronic expansion valve provided by the present invention;

FIG. 2 illustrates a structural schematic of a stator assembly provided by the present invention;

fig. 3 shows a schematic structural view of a valve sleeve provided by the present invention.

Wherein the figures include the following reference numerals:

10. a valve body; 11. an accommodating chamber; 12. a valve port; 20. a rotor assembly; 30. a stator assembly; 31. an upper polar plate; 32. a lower polar plate; 40. a screw assembly; 41. a screw; 411. cutting the structure of a section; 42. a nut sleeve; 50. a valve housing; 51. a through hole; 511. a first bore section; 512. a second bore section; 513. a third bore section; 60. a fixing member; 61. and connecting the holes.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the utility model, its application, or uses. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

As shown in fig. 1, an embodiment of the present invention provides an electronic expansion valve, which includes a valve body 10, a rotor assembly 20, a stator assembly 30, a screw assembly 40, and a valve housing 50. The valve body 10 is provided with a containing cavity 11 and a valve port 12, and the containing cavity 11 is communicated with the valve port 12; the rotor assembly 20 is disposed in the accommodation chamber 11; the stator assembly 30 is sleeved outside the valve body 10, and the stator assembly 30 and the rotor assembly 20 are arranged correspondingly; the screw assembly 40 is arranged in the accommodating cavity 11, the screw assembly 40 comprises a screw 41 and a nut sleeve 42, the nut sleeve 42 is fixed on the valve body 10, the screw 41 is arranged in the nut sleeve 42 in a penetrating way and is in threaded connection with the nut sleeve 42, the rotor assembly 20 is fixedly connected with one end of the screw 41, which is far away from the valve port 12, and the rotor assembly 20 drives the screw 41 to rotate along the nut sleeve 42, so that the screw 41 and the rotor assembly 20 move along the direction towards or away from the valve port 12; the screw 41 is in driving connection with a valve housing 50, and the valve housing 50 is used for blocking or opening the valve port 12. When the rotor assembly 20 moves towards or away from the valve port 12, the facing area of the rotor assembly 20 and the stator assembly 30 changes, and the driving force of the rotor assembly 20 changes. The pulse number is 0 when the valve port 12 is in a fully closed state, the pulse number is a when the valve port 12 is in a fully open state, the corresponding pulse number is B when the central line of the stator assembly 30 perpendicular to the axis is superposed with the central line of the rotor assembly 20 perpendicular to the axis, and B is not less than 0.3 x a and not more than 0.7 x a. In particular, B may be 0.3 a, 0.4 a, 0.5 a or 0.7 a.

By applying the technical scheme of the utility model, when the central line of the stator assembly 30 perpendicular to the axis is coincident with the central line of the rotor assembly 20 perpendicular to the axis, the force for driving the screw rod 41 to rotate by the rotor assembly 20 is the largest. If the pulse number B is less than 0.3 × a, the force is too small in the fully open state of the valve, so that step loss is likely to occur and the valve cannot operate. If the pulse number B is greater than 0.7 a, the force will be too low in the fully closed state of the valve, and the valve port 12 will not open. Therefore, the relationship between a and B is set to 0.3 a ≤ B ≤ 0.7 a, and the driving force of the rotor assembly 20 is maximized when the valve port 12 is in a close-to-half open state, so that the driving force is balanced during opening or closing the valve port 12, and the valve port 12 is more reliably opened or closed, thereby fully opening or closing the valve port 12.

Wherein, B is 0.5A. When B is 0.5 × a, the driving force of the rotor assembly 20 is the largest when the valve port 12 is in the half-open state, so that the driving force is equalized during the opening or closing of the valve port 12, and the opening or closing of the valve port 12 is more reliable.

In the present embodiment, the length of the rotor assembly 20 in the axial direction is L1, the stator assembly 30 has an upper pole plate 31 and a lower pole plate 32 which are arranged at intervals in the axial direction, the distance between the upper pole plate 31 and the lower pole plate 32 is L2, and L2 is greater than L1. Windings are arranged between the upper pole plate 31 and the lower pole plate 32, the center line of the windings, which is perpendicular to the axis, is overlapped with the center line of the stator assembly 30, which is perpendicular to the axis, and the windings and the rotor assembly 20 interact to generate driving force. If L2 is less than L1, the area of the windings facing the rotor assembly 20 is smaller, resulting in a smaller maximum driving force. Therefore, L2 is larger than L1, and the maximum driving force can be ensured to be large.

Specifically, L2-L1 is more than or equal to 0.2mm and less than or equal to 1mm. If L2-L1 < 0.2mm, the maximum driving force continues with a shorter covered stroke as the rotor assembly 20 moves closer to or farther from the valve port 12. If L2-L1 > 1mm, the structural size of the stator assembly 30 is large, resulting in a large overall structural size of the electronic expansion valve, which is not favorable for miniaturization design. Therefore, the L2-L1 with the thickness of 0.2mm or more and 1mm or less can ensure that the stroke covered by the maximum driving force continuously is longer and the structure of the electronic expansion valve is compact. Specifically, L2-L1 may be 0.2mm, 0.4mm, 0.6mm, or 1mm.

In the embodiment, the outer diameter of the rotor assembly 20 is D1, the inner diameter of the accommodating cavity 11 is D2, and D2-D1 are more than or equal to 0.3mm and less than or equal to 1mm. If D2-D1 < 0.3mm, the clearance between the rotor assembly 20 and the inner wall of the accommodating chamber 11 is too small, so that the friction between the rotor assembly 20 and the inner wall of the accommodating chamber 11 is too large when the rotor assembly 20 rotates, the rotation of the rotor assembly 20 is affected, and the rotor assembly 20 is worn. If D2-D1 > 1mm, the distance between the rotor assembly 20 and the stator assembly 30 is too large, resulting in a reduction in drive force. Therefore, the friction between the rotor assembly 20 and the inner wall of the accommodating cavity 11 when the rotor assembly rotates can be smaller and the driving force can be larger by making D2-D1 be smaller than or equal to 1mm. In particular, D2-D1 may be 0.3mm, 0.6mm, or 1mm.

As shown in FIG. 2, in the present embodiment, the outer diameter of the valve body 10 is D3, the inner diameter of the stator assembly 30 is D4, and D4-D3 are 0.5mm or less. If D4-D3 is less than 0.05mm, the clearance between the stator assembly 30 and the valve body 10 is too small, making it difficult to mount the stator assembly 30 on the valve body 10. If D4-D3 > 0.5mm, the clearance between the stator assembly 30 and the valve body 10 is too large, resulting in too large a clearance between the stator assembly 30 and the rotor assembly 20, which in turn results in a reduction in driving force. Therefore, the diameter D4-D3 is not less than 0.05mm and not more than 0.5mm, so that the stator assembly 30 can be conveniently arranged on the valve body 10, and the driving force is large.

Specifically, D1 is more than or equal to 13mm and less than or equal to 18 mm. If D1 < 13mm, the rotor assembly 20 has a small structural size and the force between the rotor assembly 20 and the stator assembly 30 is weak, resulting in a small driving force. If D1 is greater than 18mm, the rotor assembly 20 has a large size, which is not favorable for the compact design of the electronic expansion valve. Therefore, the D1 is more than or equal to 13mm and less than or equal to 18mm, which not only can ensure larger driving force, but also can make the structure of the electronic expansion valve compact. In the prior art, because there is a large pressure difference across the valve sleeve 50 during the opening of the valve port 12 by the valve sleeve 50, a large-sized rotor assembly 20 and stator assembly 30 are required to provide a sufficient driving force to overcome the pressure difference, so as to drive the valve sleeve 50 to fully open the valve port 12, and the rotor assembly 20 is generally used to have an outer diameter ranging from 25mm to 35 mm. In this embodiment, because the balance channel is provided, the pressures at the two ends of the valve sleeve 50 tend to be balanced when the valve sleeve 50 opens the valve port 12, so that the driving force provided by the rotor assembly 20 and the stator assembly 30 can be reduced, and further, in this embodiment, the value range of the outer diameter D1 of the rotor assembly 20 is set to be 13mm or more and D1 or more and 18mm or less, so that the requirement of the miniaturization design of the electronic expansion valve is met.

Specifically, L1 is more than or equal to 18mm and less than or equal to 23 mm. If L1 < 18mm, the length of the rotor assembly 20 is small and the force between the rotor assembly 20 and the stator assembly 30 is weak, resulting in a small driving force. If L1 is greater than 23mm, the length of the rotor assembly 20 is greater, and the length of the electronic expansion valve is longer. Therefore, the L1 which is more than or equal to 18mm and less than or equal to 23mm can ensure that the driving force is larger and the length of the electronic expansion valve is smaller.

In this embodiment, a balance passage is provided in the valve housing 50, and the balance passage enables both ends of the valve housing 50 to communicate with each other. The balance channel is provided to balance the air pressure at the two ends of the valve sleeve, so that a smaller driving force can drive the valve sleeve 50 to open or close the valve port 12.

As shown in fig. 3, a through hole 51 is formed in the valve housing 50, the through hole 51 includes a first hole section 511, a second hole section 512 and a third hole section 513, which are sequentially arranged, the diameters of the first hole section 511 and the third hole section 513 are larger than that of the second hole section 512, one end of the screw 41 close to the valve port 12 is inserted into the third hole section 513, one end of the screw 41 close to the valve port 12 is fixedly connected with a fixing member 60, the diameter of the fixing member 60 is larger than that of the second hole section 512, the fixing member 60 is arranged at one end of the third hole section 513 far from the valve port 12, the fixing member 60 is provided with a connecting hole 61, the end of the screw 41 is inserted into the connecting hole 61, a tangent plane structure 411 is arranged on the side wall of one end of the screw 41 close to the valve port 12, the tangent plane structure 411 extends to the first hole section 511, a first gap is formed between the tangent plane structure 411 and the inner wall of the through hole 51, a second gap is formed between the connecting hole 61 and the tangent plane structure 411, the first gap communicates with the second gap, which form a balancing channel to balance the air pressure across the valve sleeve 50. The diameter of the second bore section 512 is close to or the same as the diameter of the screw 41 to prevent the valve sleeve 50 from wobbling relative to the screw 41. A tangential structure 411 is disposed at an end of the screw 41 close to the valve port 12, the tangential structure 411 extends to the first hole section 511, a connection hole 61 is disposed on the fixing member 60, and the connection hole 61 is disposed corresponding to the tangential structure 411 to balance the air pressure at the two ends of the valve housing 50. The connecting hole 61 and the tangent plane structure 411 are arranged, so that air pressure at two ends of the valve sleeve can be balanced, and the valve sleeve 50 can be driven to open or close the valve port 12 by small driving force. Therefore, the relationship between a and B is set to 0.3 a ≦ B ≦ 0.7 a, which can satisfy the driving effect while taking into consideration the driving force for the valve sleeve 50 at the fully open position and the closed position.

It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments according to the present application. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, and it should be understood that when the terms "comprises" and/or "comprising" are used in this specification, they specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof, unless the context clearly indicates otherwise.

The relative arrangement of the components and steps, the numerical expressions and numerical values set forth in these embodiments do not limit the scope of the present invention unless specifically stated otherwise. Meanwhile, it should be understood that the sizes of the respective portions shown in the drawings are not drawn in an actual proportional relationship for the convenience of description. Techniques, methods, and apparatus known to those of ordinary skill in the relevant art may not be discussed in detail but are intended to be part of the specification where appropriate. In all examples shown and discussed herein, any particular value should be construed as merely illustrative, and not limiting. Thus, other examples of the exemplary embodiments may have different values. It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, further discussion thereof is not required in subsequent figures.

In the description of the present invention, it is to be understood that the orientation or positional relationship indicated by the orientation words such as "front, rear, upper, lower, left, right", "lateral, vertical, horizontal" and "top, bottom", etc. are usually based on the orientation or positional relationship shown in the drawings, and are only for convenience of description and simplicity of description, and in the case of not making a reverse description, these orientation words do not indicate and imply that the device or element being referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore, should not be considered as limiting the scope of the present invention; the terms "inner and outer" refer to the inner and outer relative to the profile of the respective component itself.

Spatially relative terms, such as "above … …," "above … …," "above … …," "above," and the like, may be used herein for ease of description to describe one device or feature's spatial relationship to another device or feature as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if a device in the figures is turned over, devices described as "above" or "on" other devices or configurations would then be oriented "below" or "under" the other devices or configurations. Thus, the exemplary term "above … …" can include both an orientation of "above … …" and "below … …". The device may be otherwise variously oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

It should be noted that the terms "first", "second", and the like are used to define the components, and are only used for convenience of distinguishing the corresponding components, and the terms have no special meanings unless otherwise stated, and therefore, the scope of the present invention should not be construed as being limited.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. An electronic expansion valve, comprising:

the valve body (10) is provided with a containing cavity (11) and a valve port (12), and the containing cavity (11) is communicated with the valve port (12);

a rotor assembly (20), the rotor assembly (20) being disposed within the housing cavity (11);

the stator assembly (30), the stator assembly (30) is sleeved outside the valve body (10), and the stator assembly (30) and the rotor assembly (20) are correspondingly arranged;

the screw assembly (40) is arranged in the accommodating cavity (11), the screw assembly (40) comprises a screw rod (41) and a nut sleeve (42), the nut sleeve (42) is fixed on the valve body (10), the screw rod (41) is arranged in the nut sleeve (42) in a penetrating mode and is in threaded connection with the nut sleeve (42), the rotor assembly (20) is fixedly connected with one end, far away from the valve port (12), of the screw rod (41), and the rotor assembly (20) drives the screw rod (41) to rotate along the nut sleeve (42) so that the screw rod (41) and the rotor assembly (20) move in the direction towards or far away from the valve port (12);

a valve housing (50), wherein the screw (41) is in driving connection with the valve housing (50), and the valve housing (50) is used for blocking or opening the valve port (12);

the pulse number is 0 when the valve port (12) is in a fully closed state, the pulse number is A when the valve port (12) is in a fully open state, the corresponding pulse number is B when the central line of the stator assembly (30) perpendicular to the axis is superposed with the central line of the rotor assembly (20) perpendicular to the axis, and B is more than or equal to 0.3 and less than or equal to 0.7.

2. The electronic expansion valve according to claim 1, wherein B is 0.5 a.

3. An electronic expansion valve according to claim 1, wherein the rotor assembly (20) has an axial length of L1, the stator assembly (30) has axially spaced upper and lower plates (31, 32), the distance between the upper and lower plates (31, 32) being L2, and L2 being greater than L1.

4. The electronic expansion valve of claim 3, wherein 0.2mm ≦ L2-L1 ≦ 1mm.

5. An electronic expansion valve according to claim 1, wherein the rotor assembly (20) has an outer diameter D1, and the receiving chamber (11) has an inner diameter D2, 0.3mm ≦ D2-D1 ≦ 1mm.

6. An electronic expansion valve according to claim 1, wherein the valve body (10) has an outer diameter D3 and the stator assembly (30) has an inner diameter D4, 0.05mm ≦ D4-D3 ≦ 0.5 mm.

7. An electronic expansion valve according to claim 5, wherein 13mm ≦ D1 ≦ 18 mm.

8. An electronic expansion valve according to claim 3, wherein 18mm ≦ L1 ≦ 23 mm.

9. An electronic expansion valve according to any of claims 1-8, wherein a balancing channel is provided in the valve housing (50), said balancing channel enabling communication between the two ends of the valve housing (50).

10. The electronic expansion valve according to claim 9, wherein the valve housing (50) has a through hole (51) therein, the through hole (51) comprises a first hole section (511), a second hole section (512) and a third hole section (513) which are sequentially arranged, the diameters of the first hole section (511) and the third hole section (513) are larger than the diameter of the second hole section (512), one end of the screw rod (41) close to the valve port (12) is inserted into the third hole section (513), one end of the screw rod (41) close to the valve port (12) is fixedly connected with a fixing member (60), the diameter of the fixing member (60) is larger than the diameter of the second hole section (512), the fixing member (60) is arranged at one end of the third hole section (513) far away from the valve port (12), and a connecting hole (61) is arranged on the fixing member (60), the end part of the screw rod (41) is arranged in the connecting hole (61) in a penetrating mode, a tangent plane structure (411) is arranged on the side wall of one end, close to the valve port (12), of the screw rod (41), the tangent plane structure (411) extends to the first hole section (511), a first gap is formed between the tangent plane structure (411) and the inner wall of the through hole (51), a second gap is formed between the connecting hole (61) and the tangent plane structure (411), the first gap is communicated with the second gap, and the first gap and the second gap form the balance channel so as to balance air pressure at two ends of the valve sleeve (50).