Check valve

Abstract

The utility model relates to the technical field of valves, and discloses a check valve, which comprises a valve body, a valve core, a valve core, a valve core and a valve core, the aperture of the first through hole is larger than that of the second through hole, and a step surface is formed at the joint of the first through hole and the second through hole; the support is arranged in the first through hole and is provided with a first mounting through hole which is communicated with the first through hole and is coaxial with the first through hole; the valve clack is arranged in the first through hole and comprises a valve clack body and a valve clack handle arranged on one side of the valve clack body, and the valve clack body is in lap joint with the step surface and is suitable for sealing the second through hole; the valve clack handle is movably arranged in the first mounting through hole in a penetrating manner; and the elastic piece is arranged between the valve clack body and the support. According to the check valve, the elastic piece is arranged between the valve clack body and the support, the opening pressure of the check valve can be dynamically adjusted through the elastic performance of the elastic piece, and therefore the check valve can better adapt to fluid pressure and flow changes under different working conditions, and the performance of a pipeline system is optimized.

Description

Technical Field

[0001] The utility model relates to the technical field of valves, in particular to a check valve. Background Art

[0002] As a one-way sealing valve, the check valve plays an important role in the pipeline. However, since the opening pressure of the check valve in the related art is fixed and cannot be adjusted after leaving the factory, the adaptability of the check valve in the pipeline system will be subject to certain restrictions. Utility Model Content

[0003] In view of this, the utility model provides a check valve to solve the problem that the opening pressure of the check valve in the related art cannot be adjusted.

[0004] The utility model provides a check valve, comprising:

[0005] The valve body is provided with a first through hole and a second through hole which are coaxial and connected; the aperture of the first through hole is larger than the aperture of the second through hole, and a step surface is formed at the connection between the first through hole and the second through hole;

[0006] A support, disposed in the first through hole, and provided with a first mounting through hole which is connected to and coaxial with the first through hole;

[0007] A valve flap, arranged in the first through hole, comprising a valve flap body and a valve flap handle arranged on one side of the valve flap body, the valve flap body overlaps the step surface and is suitable for sealing the second through hole; the valve flap handle can be movably inserted into the first mounting through hole;

[0008] The elastic member is arranged between the valve flap body and the support.

[0009] Beneficial effects: The utility model allows the aperture of the first through hole to be larger than the aperture of the second through hole, which can conveniently provide a larger operating space for the staff and facilitate the installation of the valve flap and the elastic member to the preset position. In addition, by arranging the elastic member between the valve flap body and the support, the elastic properties of the elastic member itself can be used to realize dynamic adjustment of the opening pressure of the check valve, that is, the elastic member can dynamically adjust its thrust on the valve flap according to the fluid pressure and flow changes in the pipeline, so that the check valve can better adapt to the fluid pressure and flow changes under different working conditions and optimize the performance of the pipeline system. Furthermore, the valve flap handle is inserted into the first mounting through hole, which can ensure that the valve flap handle always maintains linear motion in the mounting through hole, reduce shaking during movement, and improve the stability of movement, so that the valve flap body can always return to the preset position and complete the sealing of the second through hole.

[0010] In an optional embodiment, the support is further provided with an annular channel surrounding the first mounting through hole, and at least one pair of oppositely arranged holding portions are provided between the annular channel and the first mounting through hole; the annular channel is in communication with the first through hole.

[0011] Beneficial effects: The utility model provides an annular channel connected to the first through hole on the support, so that the annular channel can become a fluid flow channel when the check valve is in an open state, reducing the resistance in the fluid flow process and ensuring that the fluid can flow smoothly through the check valve. In addition, by providing at least one pair of gripping parts arranged opposite to each other between the annular channel and the first installation through hole, it is possible to improve the convenience of the staff in installing the support on the valve body and reduce the difficulty of operation.

[0012] In an optional implementation, the annular channel is arranged concentrically with the first mounting through hole.

[0013] Beneficial effects: The utility model sets the annular channel and the first mounting through hole concentrically, which can simplify the production process of preparing the support on the one hand; on the other hand, it can ensure the stability of the flow of the fluid at various positions between the annular channel and the first mounting through hole, thereby improving the durability and reliability of the check valve.

[0014] In an optional embodiment, a fixing sleeve threadedly connected to the first mounting through hole is provided in the first mounting through hole, and the valve flap handle can be movably inserted into the fixing sleeve.

[0015] Beneficial effects: The utility model can improve the convenience of installation and disassembly by providing a fixing sleeve threadedly connected to the first installation through hole; on the other hand, when the fixing sleeve is worn or damaged, only the fixing sleeve needs to be replaced without replacing the entire check valve, which can reduce maintenance costs and time. In addition, the valve flap handle is movably inserted into the fixing sleeve, which allows the fixing sleeve to provide a stable guide and support for the valve flap handle, making the valve flap handle more stable during movement, and reducing the risk of reduced sealing performance of the valve flap body to the second through hole due to shaking or offset.

[0016] In an optional embodiment, the first mounting through hole is configured as a first stepped hole, and the shape of the outer side wall of the fixing sleeve is adapted to the shape of the first stepped hole.

[0017] Beneficial effect: The utility model sets the first mounting through hole as the first stepped hole, and makes the outer wall shape of the fixing sleeve match the shape of the first stepped hole. Such a setting can make the small end of the fixing sleeve play a guiding role during the installation process, reduce the difficulty of assembly, and improve the efficiency of assembly.

[0018] In an optional embodiment, a plurality of spaced arc-shaped protrusions are provided on the side wall of the fixing sleeve at one end away from the valve disc, and the arc-shaped protrusions are located in the first mounting through hole and have a gap with the inner side wall of the first mounting through hole.

[0019] Beneficial effects: The utility model provides a plurality of arc-shaped protrusions arranged at intervals on the side wall of the fixed sleeve away from the valve disc, so that the staff can apply a certain rotational torque to the fixed sleeve through the corresponding tooling, so that the fixed sleeve can be firmly installed in the first installation hole. Similarly, if the fixed sleeve needs to be disassembled later, it is only necessary to apply a reverse torque to the fixed sleeve through the tooling. It can be seen that by providing a plurality of arc-shaped protrusions arranged at intervals on the side wall of the fixed sleeve away from the valve disc, the convenience of installing and disassembling the fixed sleeve is improved. In addition, by leaving a gap between the arc-shaped protrusion and the inner wall of the first installation hole, a certain operating space can be reserved for the staff, which reduces the difficulty of operation and improves work efficiency.

[0020] In an optional embodiment, the elastic member is a spring, and the spring sleeve is arranged on the outside of the valve flap handle and the fixing sleeve.

[0021] Beneficial effects: The utility model sets the elastic member as a spring, and can use the stable elastic properties of the spring itself to achieve dynamic adjustment of the opening pressure of the check valve, so that the check valve can better adapt to the changes in fluid pressure and flow under different working conditions, ensuring the normal operation of the pipeline system. In addition, the spring itself has a simple structure, is easy to install, and has high reliability and durability.

[0022] In an optional implementation, a dovetail groove is provided on a side of the valve flap body facing the second through hole, and a sealing ring is provided in the dovetail groove.

[0023] Beneficial effect: The utility model fixes the sealing ring by means of a dovetail groove, which can reduce the possibility of the sealing ring falling off the valve flap body. In addition, by arranging the sealing ring on the valve flap body, a soft seal of the second through hole can be achieved, that is, the sealing ring can be closely attached to the step surface, thereby improving the sealing effect of the second through hole.

[0024] In an optional embodiment, the first through hole includes a coaxially arranged second stepped hole and a second mounting through hole, the support is arranged in the second stepped hole and adapted to the shape of the second stepped hole, and the valve flap and the elastic member are arranged in the second mounting through hole.

[0025] Beneficial effects: The utility model allows the outer wall shape of the support to match the shape of the second stepped hole. This arrangement allows the small end of the support to play a guiding role during the installation process, reducing the difficulty of assembly and improving the efficiency of assembly. In addition, the second stepped hole is coaxially arranged with the second installation through hole. On the one hand, it can ensure the centering of the support, the valve disc and the elastic member during installation, and enhance the structural stability and working reliability of the entire device; on the other hand, it can reduce the space required for assembly, making the entire device more compact.

[0026] In an optional embodiment, the inner side wall of the large end of the second stepped hole is connected to the outer side wall of the support via threads.

[0027] Beneficial effects: The utility model allows the inner wall of the large end of the second step hole to be connected to the outer wall of the support through threads, which can improve the convenience of installation and disassembly on the one hand; on the other hand, when the support is worn or damaged, only the support needs to be replaced alone without replacing the entire check valve, which can reduce maintenance costs and time. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the specific implementation methods of the utility model or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0029] Figure 1 This is a structural schematic diagram of a check valve according to an embodiment of the utility model;

[0030] Figure 2 for Figure 1 A schematic top view of the check valve shown;

[0031] Figure 3 for Figure 1 A is a partial enlarged schematic diagram;

[0032] Figure 4 This is a schematic diagram of the structure of the valve body of an embodiment of the utility model;

[0033] Figure 5 for Figure 4 A schematic top view of the valve body shown;

[0034] Figure 6 It is a structural schematic diagram of a support according to an embodiment of the utility model;

[0035] Figure 7 for Figure 6 A schematic top view of the support shown;

[0036] Figure 8 A schematic diagram of the structure of the valve flap of an embodiment of the utility model;

[0037] Fig. 9 This is a schematic diagram of the structure of the fixing sleeve of an embodiment of the utility model;

[0038] Fig.10 for Fig. 9 A top view of the fixing sleeve is shown.

[0039] Description of reference numerals:

[0040] 1. Valve body; 101. First through hole; 1011. Second stepped hole; 1012. Second mounting through hole; 102. Second through hole; 103. Step surface; 2. Support; 201. First mounting through hole; 2011. First stepped hole; 202. Annular channel; 203. Grip; 3. Valve flap; 301. Valve flap body; 3011. Dovetail groove; 3012. Sealing ring; 302. Valve flap handle; 4. Elastic member; 401. Spring; 5. Fixing sleeve; 501. Arc-shaped protrusion; 6. Screw. DETAILED DESCRIPTION

[0041] In order to make the purpose, technical solution and advantages of the embodiment of the utility model clearer, the technical solution in the embodiment of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiment of the utility model. Obviously, the described embodiment is a part of the embodiment of the utility model, not all the embodiments. Based on the embodiment of the utility model, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the utility model.

[0042] Aiming at the problem that the opening pressure of the check valve in the related art cannot be adjusted, the utility model provides a check valve.

[0043] Combine the following Figures 1 to 10 , describing an embodiment of the utility model.

[0044] According to the embodiments of the present utility model, Figures 1 to 10 As shown, a check valve is provided, comprising: a valve body 1, a support 2, a valve disc 3 and an elastic member 4.

[0045] Specifically, the valve body 1 is provided with a first through hole 101 and a second through hole 102 which are coaxial and connected; the aperture of the first through hole 101 is larger than the aperture of the second through hole 102, and a step surface 103 is formed at the connection between the first through hole 101 and the second through hole 102; the support 2 is arranged in the first through hole 101, and is provided with a first mounting through hole 201 which is connected to and coaxial with the first through hole 101; the valve flap 3 is arranged in the first through hole 101, including a valve flap body 301 and a valve flap handle 302 arranged on one side of the valve flap body 301, the valve flap body 301 is overlapped on the step surface 103, and is suitable for sealing the second through hole 102; the valve flap handle 302 can be movably penetrated in the first mounting through hole 201; the elastic member 4 is arranged between the valve flap body 301 and the support 2.

[0046] The embodiment of the utility model makes the aperture of the first through hole 101 larger than the aperture of the second through hole 102, which can conveniently provide a larger operating space for the staff and facilitate the installation of the valve flap 3 and the elastic member 4 to the preset position. In addition, by arranging the elastic member 4 between the valve flap body 301 and the support 2, the elastic properties of the elastic member 4 itself can be used to realize the dynamic adjustment of the opening pressure of the check valve, that is, the elastic member 4 can dynamically adjust its thrust on the valve flap 3 according to the fluid pressure and flow changes in the pipeline, so that the check valve can better adapt to the fluid pressure and flow changes under different working conditions and optimize the performance of the pipeline system. Furthermore, the valve flap handle 302 is inserted into the first installation through hole 201, which can ensure that the valve flap handle 302 always maintains linear motion in the installation through hole, reduces shaking during the movement, and improves the stability of the movement, so that the valve flap body 301 can always return to the preset position and complete the sealing of the second through hole 102.

[0047] It should be noted that the check valve in this embodiment has an open state and a closed state. When the check valve is in the open state, the fluid in the second through hole 102 will push the valve flap 3 and the elastic member 4 to move in the direction away from the second through hole 102 until the elastic member 4 is compressed to the maximum extent, or the valve flap body 301 abuts against the support 2; in the closed state, that is, when the force exerted by the fluid in the second through hole 102 on the main body of the valve body 1 is less than the force exerted by the elastic member 4 on the main body of the valve body 1, the valve flap body 301 will always maintain an abutment state with the step surface 103 under the elastic action of the elastic member 4, and separate the first through hole 101 from the second through hole 102. It can be seen that the check valve in this embodiment has a unidirectional conduction function through the elastic member 4.

[0048] It should be noted that the valve body 1 in this embodiment can be a forging or a casting. In addition, the step surface 103 can be clad with a wear-resistant and corrosion-resistant alloy such as stainless steel or nickel-based alloy to improve the wear resistance of the step surface 103.

[0049] According to one embodiment of the utility model, Figure 2 and Figure 7 As shown, the support 2 is also provided with an annular channel 202 surrounding the first mounting through hole 201, and at least one pair of gripping portions 203 are arranged oppositely between the annular channel 202 and the first mounting through hole 201; the annular channel 202 is connected to the first through hole 101. In the embodiment of the utility model, by providing the annular channel 202 connected to the first through hole 101 on the support 2, the annular channel 202 can become the fluid flow channel of the check valve in the open state, reduce the resistance in the fluid flow process, and ensure that the fluid can flow smoothly through the check valve. In addition, by providing at least one pair of gripping portions 203 arranged oppositely between the annular channel 202 and the first mounting through hole 201, the convenience of the staff in installing the support 2 on the valve body 1 can be improved, and the difficulty of operation can be reduced.

[0050] According to one embodiment of the utility model, Figure 2 and Figure 7 As shown, the annular channel 202 is concentrically arranged with the first mounting through hole 201. In the embodiment of the utility model, the annular channel 202 is concentrically arranged with the first mounting through hole 201, which can simplify the production process of preparing the support 2 on the one hand; on the other hand, it can ensure the stability of the flow of the fluid at various positions between the annular channel 202 and the first mounting through hole 201, thereby improving the durability and reliability of the check valve.

[0051] According to one embodiment of the utility model, Figure 1 , Figure 3 , Fig. 9 as well as Fig.10 As shown, a fixing sleeve 5 threadedly connected to the first mounting through hole 201 is provided in the first mounting through hole 201, and the valve flap handle 302 is movably inserted into the fixing sleeve 5. The embodiment of the utility model can improve the convenience of installation and disassembly by providing a fixing sleeve 5 threadedly connected to the first mounting through hole 201 in the embodiment of the utility model; on the other hand, when the fixing sleeve 5 is worn or damaged, only the fixing sleeve 5 needs to be replaced separately without replacing the entire check valve, which can reduce the maintenance cost and time. In addition, the valve flap handle 302 is movably inserted into the fixing sleeve 5, so that the fixing sleeve 5 can provide a stable guide and support for the valve flap handle 302, so that the valve flap handle 302 is more stable during movement, and the risk of the valve flap body 301 reducing the sealing performance of the second through hole 102 due to shaking or offset is reduced.

[0052] It should be noted that, in order to ensure that the valve flap handle 302 can move stably in the fixing sleeve 5 , in a specific embodiment, the valve flap handle 302 and the fixing sleeve 5 are connected by a clearance fit.

[0053] It should be supplemented that, in order to improve the connection strength between the fixing sleeve 5 and the support 2 , after the fixing sleeve 5 and the support 2 are threadedly connected, they can be further fixed by using fasteners such as screws 6 .

[0054] It is understandable that, in order to improve the wear resistance of the valve flap handle 302 and extend the service life of the valve flap handle 302, the entire valve flap handle 302 or a part of the valve flap handle 302 may be hardened. In addition, in order to improve the aesthetics of the check valve, the side of the fixing sleeve 5 and the side of the support 2 away from the valve flap 3 may be at the same height in the assembled state.

[0055] According to one embodiment of the utility model, Figure 1 and Figure 6 As shown, the first mounting through hole 201 is set as a first stepped hole 2011, and the shape of the outer side wall of the fixing sleeve 5 is adapted to the shape of the first stepped hole 2011. In the embodiment of the utility model, the first mounting through hole 201 is set as the first stepped hole 2011, and the shape of the outer side wall of the fixing sleeve 5 is adapted to the shape of the first stepped hole 2011. Such a setting can allow the small end of the fixing sleeve 5 to play a guiding role during the installation process, reduce the difficulty of assembly, and improve the efficiency of assembly.

[0056] According to one embodiment of the utility model, Figure 1 , Figure 3 , Fig. 9 as well as Fig.10 As shown, a plurality of arc-shaped protrusions 501 are arranged at intervals on the side wall of the fixed sleeve 5 away from the valve disc 3, and the arc-shaped protrusions 501 are located in the first mounting through hole 201 and leave a gap with the inner side wall of the first mounting through hole 201. The embodiment of the utility model provides a plurality of arc-shaped protrusions 501 arranged at intervals on the side wall of the fixed sleeve 5 away from the valve disc 3, so that the staff can apply a certain rotation torque to the fixed sleeve 5 through the corresponding tooling, so that the fixed sleeve 5 can be firmly installed in the first mounting through hole 201. Similarly, if the fixed sleeve 5 needs to be disassembled later, it is only necessary to apply a reverse torque to the fixed sleeve 5 through the tooling. It can be seen that by providing a plurality of arc-shaped protrusions 501 arranged at intervals on the side wall of the fixed sleeve 5 away from the valve disc 3, the convenience of installing and disassembling the fixed sleeve 5 is improved. In addition, by leaving a gap between the arc-shaped protrusion 501 and the inner side wall of the first mounting through hole 201, a certain operating space can be reserved for the staff, which reduces the difficulty of operation and improves work efficiency.

[0057] According to one embodiment of the utility model, Figure 1 and Figure 3As shown, the elastic member 4 is a spring 401, which is sleeved on the outside of the valve flap handle 302 and the fixing sleeve 5, one end of the spring 401 is connected to the fixing sleeve 5, and the other end is connected to the valve flap handle 302. In the embodiment of the utility model, the elastic member 4 is set as a spring 401, and the stable elastic performance of the spring 401 itself can be used to realize the dynamic adjustment of the opening pressure of the check valve, so that the check valve can better adapt to the changes in fluid pressure and flow under different working conditions, and ensure the normal operation of the pipeline system. In addition, the spring 401 itself has a simple structure, is easy to install, and has high reliability and durability.

[0058] According to one embodiment of the utility model, Figure 1 and Figure 8 As shown, a dovetail groove 3011 is provided on one side of the valve flap body 301 facing the second through hole 102, and a sealing ring 3012 is provided in the dovetail groove 3011. The embodiment of the utility model fixes the sealing ring 3012 by the dovetail groove 3011, which can reduce the possibility of the sealing ring 3012 falling off from the valve flap body 301. In addition, by arranging the sealing ring 3012 on the valve flap body 301, a soft seal of the second through hole 102 can be achieved, that is, the sealing ring 3012 can be closely attached to the step surface 103, thereby improving the sealing effect of the second through hole 102. It should be noted that the sealing ring 3012 in this embodiment can be an O-type sealing ring.

[0059] According to one embodiment of the utility model, Figure 1 , Figure 4 as well as Figure 5 As shown, the first through hole 101 includes a coaxially arranged second stepped hole 1011 and a second mounting through hole 1012, the support 2 is arranged in the second stepped hole 1011 and is adapted to the shape of the second stepped hole 1011, and the valve flap 3 and the elastic member 4 are arranged in the second mounting through hole 1012. In the embodiment of the utility model, the shape of the outer wall of the support 2 is adapted to the shape of the second stepped hole 1011. Such an arrangement enables the small end of the support 2 to play a guiding role during the installation process, thereby reducing the difficulty of assembly and improving the efficiency of assembly. In addition, the coaxial arrangement of the second stepped hole 1011 and the second mounting through hole 1012 can, on the one hand, ensure the centering of the support 2, the valve flap 3 and the elastic member 4 during installation, thereby enhancing the structural stability and working reliability of the entire device; on the other hand, it can reduce the space required for assembly, thereby making the entire device more compact.

[0060] According to one embodiment of the utility model, Figure 1 , Figure 4 as well as Figure 5As shown, the inner side wall of the large end of the second stepped hole 1011 is connected to the outer side wall of the support 2 by threads. In the embodiment of the utility model, the inner side wall of the large end of the second stepped hole 1011 is connected to the outer side wall of the support 2 by threads, which can improve the convenience of installation and disassembly on the one hand; on the other hand, when the support 2 is worn or damaged, only the support 2 needs to be replaced without replacing the entire check valve, which can reduce maintenance costs and time.

[0061] It is understandable that, since the support 2 is threadedly connected to the large end of the second stepped hole 1011, providing a gripping portion 203 on the support 2 facilitates the staff to apply a rotational torque to the support 2, thereby improving the convenience of installation and disassembly.

[0062] Although the embodiments of the present invention are described in conjunction with the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations are all within the scope defined by the appended claims.

Claims

1. A check valve, characterized in that: include: A valve body (1) is provided with a first through hole (101) and a second through hole (102) which are coaxial and connected; the diameter of the first through hole (101) is larger than the diameter of the second through hole (102), and a step surface (103) is formed at the connection between the first through hole (101) and the second through hole (102); A support (2) is arranged in the first through hole (101) and is provided with a first mounting through hole (201) which is in communication with and coaxial with the first through hole (101); A valve flap (3) is arranged in the first through hole (101), comprising a valve flap body (301) and a valve flap handle (302) arranged on one side of the valve flap body (301), wherein the valve flap body (301) overlaps the step surface (103) and is suitable for sealing the second through hole (102); the valve flap handle (302) is movably inserted into the first mounting through hole (201); An elastic member (4) is arranged between the valve flap body (301) and the support (2).

2. The check valve according to claim 1, characterized in that: The support (2) is also provided with an annular channel (202) surrounding the first mounting through hole (201), and at least one pair of gripping portions (203) arranged opposite to each other are provided between the annular channel (202) and the first mounting through hole (201); the annular channel (202) is in communication with the first through hole (101).

3. The check valve according to claim 2, characterized in that: The annular channel (202) is arranged concentrically with the first mounting through hole (201).

4. The check valve according to claim 1, characterized in that: A fixing sleeve (5) threadedly connected to the first mounting through hole (201) is provided in the first mounting through hole (201), and the valve flap handle (302) is movably inserted into the fixing sleeve (5).

5. The check valve according to claim 4, characterized in that: The first mounting through hole (201) is configured as a first stepped hole (2011), and the shape of the outer side wall of the fixing sleeve (5) is adapted to the shape of the first stepped hole (2011).

6. The check valve according to claim 4, characterized in that: A plurality of arc-shaped protrusions (501) arranged at intervals are provided on the side wall of the fixing sleeve (5) at one end away from the valve flap (3); the arc-shaped protrusions (501) are located in the first mounting through hole (201) and have a gap with the inner side wall of the first mounting through hole (201).

7. The check valve according to claim 4, characterized in that: The elastic member (4) is a spring (401), and the spring (401) is sleeved on the outside of the valve flap handle (302) and the fixing sleeve (5).

8. The check valve according to any one of claims 1 to 7, characterized in that: A dovetail groove (3011) is provided on one side of the valve flap body (301) facing the second through hole (102), and a sealing ring (3012) is provided in the dovetail groove (3011).

9. The check valve according to any one of claims 1 to 7, characterized in that: The first through hole (101) comprises a second stepped hole (1011) and a second mounting through hole (1012) which are coaxially arranged; the support (2) is arranged in the second stepped hole (1011) and is adapted to the shape of the second stepped hole (1011); and the valve flap (3) and the elastic member (4) are arranged in the second mounting through hole (1012).

10. The check valve according to claim 9, characterized in that The inner side wall of the large end of the second stepped hole (1011) is connected to the outer side wall of the support (2) via threads.

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