WO2023088253A1 - Electronic expansion valve - Google Patents

Abstract

Disclosed is an electronic expansion valve, comprising: a valve casing (10) having a valve cavity (11) and a valve port (12) communicated with each other; a nut seat (30) provided in the valve cavity (11) and connected to the valve casing (10) and provided with a threaded through hole (31); a valve needle (20) movably provided in the threaded through hole (31) in a penetrating mode and provided with a first end (21) and a second end (22) opposite to each other, wherein external threads are arranged on the valve needle (20), the external threads are threadedly connected to the threaded through hole (31), the second end (22) is provided corresponding to the valve port (12), and the second end (22) is used for controlling the opening degree of the valve port (12); a magnetic rotor (40) rotatably provided in the valve cavity (11); a connecting plate (50) provided between the magnetic rotor (40) and the valve needle (20) and provided with a first through hole, wherein the first end (21) of the valve needle (20) passes through the first through hole and is fixedly connected to the connecting plate (50), and an outer ring of the connecting plate (50) is connected to the magnetic rotor (40); and a stopper (60) provided at the periphery of the nut seat (30), wherein the upper surface of the stopper (60) is connected to the bottom surface of the connecting plate (50), and a stop structure (61) is provided between the stopper (60) and the nut seat (30). The problem in the prior art of complex structure can be solved.

Description

Electronic expansion valve

This application claims the priority of the patent application with the application number 202122859274.4 and the invention name "electronic expansion valve" submitted to the State Intellectual Property Office of China on November 19, 2021.

technical field

The present application relates to the field of electronic expansion valves, in particular, to an electronic expansion valve.

Background technique

At present, the existing electronic expansion valve generally includes a valve body, a nut, a valve needle, a magnetic rotor, a connecting plate, a retaining ring and a screw rod. When in use, the nut, valve needle, magnetic rotor, connecting plate and screw rod are all arranged inside the valve body, the nut is assembled on the valve body, the screw rod is movably assembled in the nut, the valve needle is installed inside the screw rod, and the magnetic The rotor is arranged on the periphery and covers a part of the nut, the stop ring is sleeved in the magnetic rotor, and the screw rod is fixed to the connecting plate.

In the prior art, the screw rod is fixed to the connecting plate, and the valve needle is arranged inside the screw rod to realize the up and down movement of the valve needle. Such arrangement makes the internal structure of the electronic expansion valve complex, makes installation difficult, and greatly increases the production cost.

Utility model content

The present application provides an electronic expansion valve to solve the problems of complex structure and difficult installation in the prior art.

The application provides an electronic expansion valve, comprising: a valve casing, the valve casing has a valve cavity and a valve port, the valve port communicates with the valve cavity; a nut seat, the nut seat is arranged in the valve cavity and is fixedly connected with the valve casing, and the nut seat A threaded through hole is arranged on the valve needle; the valve needle is movably installed in the threaded through hole. The hole is threadedly connected, the second end of the valve needle is set corresponding to the valve port, and the second end of the valve needle is used to control the opening of the valve port; the magnetic rotor is rotatably set in the valve cavity; the connecting plate, the connecting plate is set Between the magnetic rotor and the valve needle, the connecting plate is provided with a first through hole, the first end of the valve needle is penetrated in the first through hole and is fixedly connected with the connecting plate, and the outer ring of the connecting plate is fixedly connected with the magnetic rotor The stopper is arranged on the outer periphery of the nut seat, the upper surface of the stopper is fixedly connected with the bottom surface of the connecting plate, and there is a stop structure between the stopper and the nut seat to limit the stroke of the valve needle.

Applying the technical solution of the present application, the electronic expansion valve includes a valve housing, a nut seat, a valve needle, a magnetic rotor, a connecting plate and a stopper. Wherein, the outer ring of the connecting plate is fixedly connected with the magnetic rotor, the valve needle is fixedly connected with the connecting plate through the first through hole, and the upper surface of the stopper is fixedly connected with the bottom surface of the connecting plate. When the electronic expansion valve is working, the magnetic rotor drives the connecting plate to rotate, and the connecting plate drives the valve needle and the stopper to rotate respectively, and the connecting plate and the valve needle are fixedly connected to ensure the coaxiality of the valve needle and the valve port. The above structure is adopted , the structure is simple, and the internal parts of the valve body are compact in structure, easy to install, easy to operate, and because there are fewer parts in the valve body, the cost is low.

Further, the stopper is provided with a second through hole, the second through hole is arranged coaxially with the first through hole, the second through hole includes a first hole segment and a second hole segment communicating with each other, and the valve needle passes through in sequence It is located in the second through hole and the first through hole, and the inner wall of the first hole section and the valve needle are transition fit, the end of the nut seat away from the valve port extends into the second hole section, and the stopper structure is set at Between the second hole segment and the nut seat. The valve needle passes through the first hole section and is transitionally connected with the first hole section, which can effectively prevent the valve needle from tilting and avoid the shaking of the valve needle.

Further, the stop structure includes: a first stop boss and a second stop boss, arranged at intervals along the circumferential direction of the second through hole on the inner wall of the second hole segment; stoppers, arranged on the nut seat On the outer wall, the stop part is located between the first stop boss and the second stop boss. The valve needle has the maximum opening position for opening the valve port and the closed position for blocking the valve port. When the valve needle moves to close position, the first stop boss abuts against the stop portion, and when the valve needle moves to the maximum opening position, the second stop boss abuts against the stop portion. Such setting can determine the range of up and down movement of the valve needle, which not only prevents the valve body from being too large due to the high displacement of the valve needle, but also avoids damage to the valve needle or the valve port caused by the impact of the valve needle when it falls, and improves the electronic expansion. service life of the valve.

Further, a protrusion is provided on the upper surface of the stopper, a mounting hole is provided on the connecting plate, and the protrusion is riveted into the mounting hole. The mounting hole matches the shape of the raised part to ensure the stability of the connection between the two.

Further, there are multiple protrusions and multiple installation holes, and the protrusions and the installation holes are provided in one-to-one correspondence. With such arrangement, relative displacement between the mounting plate and the stopper can be avoided.

Further, the stopper is integrated with the connecting plate. The coaxiality between the stopper and the connecting plate is good, and the structural stability between the stopper and the connecting plate is improved.

Further, the valve needle is welded to the connecting plate. This can make the connection between the valve needle and the connecting plate firm, thereby preventing the valve needle from shaking.

Further, the connecting plate and the stopper are arranged inside the magnetic rotor, and the outer side wall of the stopper is attached to the inner wall of the magnetic rotor. In this way, the stopper will not shake during the rotation process, thereby ensuring the smooth operation of the stopper.

Further, the stopper is also provided with a demoulding through hole, and the demoulding through hole is arranged corresponding to the second stop boss along the axial direction. Simplify the processing steps of the stopper to ensure the smooth progress of the demoulding process.

Further, the stop part is arranged on the side wall of the end of the nut seat away from the valve port, the stop part extends along the circumferential direction of the nut seat, and the stop part has a first end surface and a second end surface oppositely arranged; the first stop The stop boss has a first stop surface, the second stop boss has a second stop surface, one of the first end surface and the second end surface is used to fit and abut against the first stop surface, and the first end surface and the second end surface The other of the second end surfaces is used to fit and abut against the second stop surface. The surface-to-surface contact between the end surface and the stop surface can effectively reduce the pressure, and prevent the stop structure or the stop part from being damaged due to the impact force when the end surface contacts the stop surface.

Description of drawings

The accompanying drawings constituting a part of the present application are used to provide further understanding of the present application, and the schematic embodiments and descriptions of the present application are used to explain the present application, and do not constitute an improper limitation of the present application. In the attached picture:

Figure 1 shows a schematic structural view of the electronic expansion valve provided by the present application;

Figure 2 shows a schematic structural view of the stopper provided by the present application;

Figure 3 shows a schematic view of the structure of the other side of the stopper provided by the present application;

Fig. 4 shows a schematic structural view of the nut seat provided by the present application.

Wherein, the above-mentioned accompanying drawings include the following reference signs:

10. Valve housing; 11. Valve cavity; 12. Valve port; 20. Valve needle; 21. First end; 22. Second end; 30. Nut seat; 31. Threaded through hole; 32. Stopper part; 40 , magnetic rotor; 50, connecting plate; 60, stopper; 61, stop structure; 611, first stop boss; 612, second stop boss; 62, second through hole; 621, first Hole section; 622, the second hole section; 63, the demoulding through hole; 64, the raised part.

Detailed ways

The following will clearly and completely describe the technical solutions in the embodiments of the application with reference to the drawings in the embodiments of the application. Apparently, the described embodiments are only some of the embodiments of the application, not all of them. The following description of at least one exemplary embodiment is merely illustrative in nature and in no way serves as any limitation of the application, its application or uses. Based on the embodiments in this application, all other embodiments obtained by persons of ordinary skill in the art without creative efforts fall within the protection scope of this application.

As shown in FIG. 1 and FIG. 2 , Embodiment 1 of the present application provides an electronic expansion valve, which includes a valve housing 10 , a nut seat 30 , a valve needle 20 , a magnetic rotor 40 , a connecting plate 50 and a stopper 60 . The valve casing 10 has a valve chamber 11 and a valve port 12 , and the valve port 12 communicates with the valve chamber 11 . The nut seat 30 is arranged in the valve cavity 11 and is fixedly connected with the valve housing 10 , and the nut seat 30 is provided with a threaded through hole 31 . The valve needle 20 is movably installed in the threaded through hole 31, the valve needle 20 has a first end 21 and a second end 22 oppositely arranged, the valve needle 20 is provided with an external thread, and the external thread is threadedly connected with the threaded through hole 31 , the second end 22 of the valve needle 20 is disposed corresponding to the valve port 12 , and the second end 22 of the valve needle 20 is used to control the opening of the valve port 12 . The magnetic rotor 40 is rotatably disposed in the valve cavity 11 . The connecting plate 50 is arranged between the magnetic rotor 40 and the valve needle 20, the connecting plate 50 is provided with a first through hole, the first end 21 of the valve needle 20 is penetrated in the first through hole and fixedly connected with the connecting plate 50, The outer ring of the connecting plate 50 is fixedly connected with the magnetic rotor 40 . The stopper 60 is arranged on the outer periphery of the nut seat 30, the upper surface of the stopper 60 is fixedly connected with the bottom surface of the connecting plate 50, and there is a stop structure 61 between the stopper 60 and the nut seat 30 to limit the movement of the valve needle 20. journey.

According to the technical solution of the present application, the electronic expansion valve includes a valve housing 10 , a nut seat 30 , a valve needle 20 , a magnetic rotor 40 , a connecting plate 50 and a stopper 60 . Wherein, the outer ring of the connecting plate 50 is fixedly connected with the magnetic rotor 40 , the valve needle 20 is fixedly connected with the connecting plate 50 through the first through hole, and the upper surface of the stopper 60 is fixedly connected with the bottom surface of the connecting plate 50 . When the electronic expansion valve is working, the magnetic rotor 40 drives the connecting plate 50 to rotate, and the connecting plate 50 drives the valve needle 20 and the stopper 60 to rotate respectively, and the connecting plate 50 is fixedly connected to the valve needle 20 to ensure that the valve needle 20 and the valve port The coaxiality of 12, the above structure is adopted, the structure is simple, and the internal parts of the valve body are compact in structure, easy to install, easy to operate, and because there are fewer parts in the valve body, the cost is low.

Wherein, the stopper 60 is provided with a second through hole 62, the second through hole 62 is arranged coaxially with the first through hole, and the second through hole 62 includes a first hole section 621 and a second hole section 622 which communicate with each other, The valve needle 20 passes through the second through hole 62 and the first through hole in sequence, and the inner wall of the first hole section 621 and the valve needle 20 are in a transition fit, and the end of the nut seat 30 away from the valve port 12 extends into the In the second hole section 622 , the stop structure 61 is disposed between the second hole section 622 and the nut seat 30 . The valve needle 20 passes through the first hole section 621 and is transitionally connected with the first hole section 621, which can effectively prevent the valve needle 20 from tilting, avoid the shaking of the valve needle 20, and further ensure that the magnetic rotor 40, the connecting plate 50, the valve needle 20, Concentricity between stopper 60 and valve port 12.

As shown in Figure 2 and Figure 4, the stop structure 61 includes a first stop boss 611 and a second stop boss 612, the first stop boss 611 and the second stop boss 612 are along the second through hole The circumferential intervals of 62 are provided on the inner wall of the second hole segment 622 . The stopper 32 is arranged on the outer wall of the nut seat 30, the stopper 32 is located between the first stopper boss 611 and the second stopper boss 612, and the valve needle 20 has a maximum opening position for opening the valve port 12. And the closed position of blocking the valve port 12, when the valve needle 20 moves to the closed position, the first stop boss 611 abuts against the stop part 32, when the valve needle 20 moves to the maximum opening position, the second stop The blocking boss 612 abuts against the blocking portion 32 . In this embodiment, the first stopper boss 611 is located above the second stopper boss 612, and a stopper 32 is provided on the outer wall of the nut holder 30, and the stopper 32 abuts against the first stopper boss 611. , the valve needle 20 moves to the lowest position, and the valve needle 20 closes with the valve port 12 to prevent the passage of fluid; The opening with valve port 12 is the largest. Such setting can determine the range of up and down movement of the valve needle 20, which not only prevents the valve needle 20 from rising too high and causing the volume of the valve body to be too large, but also avoids the impact of the valve needle 20 on the valve port 12 when it falls, causing the valve needle 20 or the valve port 12 to break. Damage, improve the service life of the electronic expansion valve.

As shown in FIG. 3 , the upper surface of the stopper 60 is provided with a raised portion 64 , and the connecting plate 50 is provided with a mounting hole, and the raised portion 64 is riveted in the mounting hole. Optionally, the raised portion 64 is a non-cylindrical body, and the mounting hole matches the shape of the raised portion 64 to ensure the stability of the connection between the two, and to prevent the stopper 60 from colliding with the connecting plate during rotation. Relative displacement between 50. In other embodiments, the connecting plate 50 may also be fixedly connected to the stopper 60 by means of welding or the like. Further, there are multiple protrusions 64 and multiple installation holes, and the protrusions 64 are provided in one-to-one correspondence with the installation holes. One or more protrusions 64 may be provided, and in this application, a plurality of protrusions 64 are provided. As shown in FIG. 3 , three protruding portions 64 are provided. Such arrangement can avoid relative displacement between the mounting plate and the stopper 60 and ensure structural stability between the mounting plate and the stopper 60 .

Specifically, the valve needle 20 is welded to the connecting plate 50 . This can make the connection between the valve needle 20 and the connecting plate 50 firm, thereby preventing the valve needle 20 from shaking, thereby ensuring that the coaxiality between the valve needle 20 and the valve port 12 is better, and welding is adopted, which is efficient and economical Good sex.

Specifically, the connecting plate 50 and the stopper 60 are disposed inside the magnetic rotor 40 , and the outer wall of the stopper 60 is attached to the inner wall of the magnetic rotor 40 . The magnetic rotor 40 drives the connecting plate 50 and the stopper 60 to rotate at the same time, because the outer wall of the stopper 60 fits the inner wall of the magnetic rotor, the stopper 60 will not shake during the rotation process, ensuring that the stopper 60 smooth operation. The outer wall of the stopper 60 is attached to the inner wall of the magnetic rotor 40, and the structural stability between the stopper 60 and the magnetic rotor 40 is better, so that the coaxiality between the first through hole and the valve port 12 Preferably, since the first through hole and the valve needle 20 are in a transitional fit, the above-mentioned structure makes the valve needle 20 and the valve port 12 have better coaxiality.

Further, the stopper 60 is also provided with a demoulding through hole 63 , and the demoulding through hole 63 is arranged corresponding to the second stop boss 612 along the axial direction. The upper surface of the first stop boss 611 fits the upper surface of the second hole section 622, there is a certain distance between the second stop boss 612 and the upper surface of the second hole section 622, and the stopper 60 is Integral injection molding, therefore, a demoulding through hole 63 is provided on the stopper 60 , and the second stopper boss 612 is axially corresponding to the demoulding through hole 63 , which can simplify the processing steps of the stopper 60 . Optionally, the structural size of the demoulding through hole 63 is slightly larger than the structural size of the second stopper boss 612, so as to ensure the smooth progress of the demoulding process and ensure the demoulding effect.

Wherein, the stop portion 32 is arranged on the side wall of the end of the nut seat 30 away from the valve port 12, the stop portion 32 extends along the circumferential direction of the nut seat 30, and the stop portion 32 has a first end surface and a second end surface oppositely arranged. end face. The first stop boss 611 has a first stop surface, the second stop boss 612 has a second stop surface, and one of the first end surface and the second end surface is used to fit and abut against the first stop surface , the other one of the first end surface and the second end surface is used to fit and abut against the second stop surface. The surface-to-surface contact between the end surface and the stop surface can effectively reduce the pressure, and prevent the stop structure or the stop part from being damaged due to the impact force when the end surface contacts the stop surface. Specifically, the stop portion 32 extends along the circumferential direction of the nut seat 30 , and the first end surface and the second end surface are located on two axially extending end surfaces of the stop portion 32 . The first stop boss 611 and the second stop boss 612 extend along the radial direction of the second hole segment, the first stop surface is located on the side of the first stop boss 611, the second stop surface is located on the second The side of the stop boss 612, and the first end surface is arranged parallel to the first stop surface, and the second end surface is arranged parallel to the second stop surface, so that the stop part 32 can reach the maximum opening position or In the closed position, the end surface of the stop portion 32 can be completely attached to the stop surface.

Through the technical solution of the present application, the first end of the valve needle 20 is fixedly connected with the first through hole of the connecting plate 50, the external thread provided in the middle of the valve needle 20 is threadedly connected with the threaded through hole 31 of the nut seat 30, and the internal structure of the valve body Simple, with fewer parts, easy installation and easy operation.

Embodiment 2 of the present application provides an electronic expansion valve, which is different from Embodiment 1 in that: the stopper 60 is integrated with the connecting plate 50 . The stopper 60 and the connection plate 50 can be integrally injection-molded, so that the coaxiality between the stopper 60 and the connection plate 50 is better, and the structural stability between the stopper 60 and the connection plate 50 is improved. In addition, the processing steps of the stopper 60 and the connecting plate 50 are simplified, the installation efficiency is improved, and labor is saved.

It should be noted that the terminology used here is only for describing specific implementations, and is not intended to limit the exemplary implementations according to the present application. As used herein, unless the context clearly dictates otherwise, the singular is intended to include the plural, and it should also be understood that when the terms "comprising" and/or "comprising" are used in this specification, they mean There are features, steps, operations, means, components and/or combinations thereof.

The relative arrangements of components and steps, numerical expressions and numerical values set forth in these embodiments do not limit the scope of the present application unless specifically stated otherwise. At the same time, it should be understood that, for the convenience of description, the sizes of the various parts shown in the drawings are not drawn according to the actual proportional relationship. Techniques, methods and devices known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, such techniques, methods and devices should be considered part of the Authorized Specification. In all examples shown and discussed herein, any specific values should be construed as illustrative only, and not as limiting. Therefore, other examples of the exemplary embodiment may have different values. It should be noted that like numerals and letters denote like items in the following figures, therefore, once an item is defined in one figure, it does not require further discussion in subsequent figures.

In the description of the present application, it should be understood that orientation words such as "front, back, up, down, left, right", "horizontal, vertical, vertical, horizontal" and "top, bottom" etc. indicate the orientation Or positional relationship is generally based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the application and simplifying the description. In the absence of a contrary statement, these orientation words do not indicate or imply the device or element referred to It must have a specific orientation or be constructed and operated in a specific orientation, so it should not be construed as limiting the protection scope of the present application; the orientation words "inner and outer" refer to the inner and outer relative to the outline of each component itself.

For the convenience of description, spatially relative terms may be used here, such as "on ...", "over ...", "on the surface of ...", "above", etc., to describe The spatial positional relationship between one device or feature shown and other devices or features. 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 the device in the figures is turned over, devices described as "above" or "above" other devices or configurations would then be oriented "beneath" or "above" the other devices or configurations. under other devices or configurations". Thus, the exemplary term "above" can encompass both an orientation of "above" and "beneath". The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptions used herein interpreted accordingly.

In addition, it should be noted that the use of words such as "first" and "second" to define components is only for the convenience of distinguishing corresponding components. To limit the protection scope of this application.

The above descriptions are only preferred embodiments of the present application, and are not intended to limit the present application. For those skilled in the art, there may be various modifications and changes in the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of this application shall be included within the protection scope of this application.

Claims (10)

An electronic expansion valve, characterized in that it comprises: A valve casing (10), the valve casing (10) has a valve cavity (11) and a valve port (12), and the valve port (12) communicates with the valve cavity (11); A nut seat (30), the nut seat (30) is arranged in the valve cavity (11) and is fixedly connected with the valve casing (10), and the nut seat (30) is provided with a threaded through hole (31 ); A valve needle (20), the valve needle (20) is movably penetrated in the threaded through hole (31), and the valve needle (20) has a first end (21) and a second end arranged oppositely (22), the valve needle (20) is provided with an external thread, and the external thread is threadedly connected with the threaded through hole (31), and the second end (22) of the valve needle (20) corresponds to the The valve port (12) is set, and the second end (22) of the valve needle (20) is used to control the opening of the valve port (12); a magnetic rotor (40), the magnetic rotor (40) is rotatably arranged in the valve chamber (11); A connecting plate (50), the connecting plate (50) is arranged between the magnetic rotor (40) and the valve needle (20), the connecting plate (50) is provided with a first through hole, the The first end (21) of the valve needle (20) passes through the first through hole and is fixedly connected with the connecting plate (50), and the outer ring of the connecting plate (50) is connected with the magnetic rotor ( 40) Fixed connection; A stopper (60), arranged on the outer periphery of the nut seat (30), the upper surface of the stopper (60) is fixedly connected with the bottom surface of the connecting plate (50), and the stopper (60) ) and the nut seat (30) have a stop structure (61) to limit the stroke of the valve needle (20). The electronic expansion valve according to claim 1, characterized in that, the stopper (60) is provided with a second through hole (62), and the second through hole (62) is connected with the first through hole Coaxially arranged, the second through hole (62) includes a first hole section (621) and a second hole section (622) that communicate with each other, and the valve needle (20) passes through the second hole section in sequence. hole (62) and the first through hole, and the inner wall of the first hole section (621) and the valve needle (20) are transition fit, and the nut seat (30) is far away from the One end of the valve port (12) protrudes into the second hole section (622), and the stop structure (61) is arranged between the second hole section (622) and the nut seat (30). The electronic expansion valve according to claim 2, characterized in that, the stopper structure (61) comprises: The first stop boss (611) and the second stop boss (612) are arranged on the inner wall of the second hole section (622) at intervals along the circumference of the second through hole (62); The stop part (32) is arranged on the outer wall of the nut seat (30), and the stop part (32) is located on the first stop boss (611) and the second stop boss (612) ), the valve needle (20) has a maximum opening position for opening the valve port (12) and a closed position for blocking the valve port (12), when the valve needle (20) moves to the In the closed position, the first stopper boss (611) abuts against the stopper portion (32), and when the valve needle (20) moves to the maximum opening position, the second The stop boss (612) abuts against the stop portion (32). The electronic expansion valve according to claim 1, characterized in that, the upper surface of the stopper (60) is provided with a raised portion (64), the connecting plate (50) is provided with a mounting hole, the The raised part (64) is riveted in the installation hole. The electronic expansion valve according to claim 4, characterized in that, there are multiple protrusions (64) and multiple mounting holes, and the protrusions (64) and the mounting holes are one by one corresponding settings. The electronic expansion valve according to claim 1, characterized in that, the stopper (60) is integrated with the connecting plate (50). The electronic expansion valve according to claim 1, characterized in that the valve needle (20) is welded to the connecting plate (50). The electronic expansion valve according to claim 1, characterized in that, the connecting plate (50) and the stopper (60) are arranged inside the magnetic rotor (40), and the stopper (60) The outer wall of the magnetic rotor (40) is attached to the inner wall. The electronic expansion valve according to claim 3, characterized in that, the stopper (60) is also provided with a demoulding through hole (63), and the demoulding through hole (63) corresponds to the The second stop boss (612) is provided. The electronic expansion valve according to claim 3, characterized in that, The stop part (32) is arranged on the side wall of the end of the nut seat (30) away from the valve port (12), and the stop part (32) is arranged along the nut seat (30). Extending in the circumferential direction, the stop portion (32) has a first end surface and a second end surface oppositely arranged; The first stop boss (611) has a first stop surface, the second stop boss (612) has a second stop surface, and one of the first end surface and the second end surface The other one of the first end surface and the second end surface is used for adhering to and abutting against the second stop surface.

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