An angle-adjustable smooth type shield machine wheel assembly

Abstract

This application discloses an angle-adjustable, stable shield tunneling machine wheel assembly, including wheel components, a connecting assembly, and an angle adjustment assembly. The wheel components are in two sets; the two sets of wheel components are movably connected via the connecting assembly; the angle adjustment assembly is connected to both sets of wheel components and is used to adjust the direction of the wheel components. The angle adjustment assembly includes a hydraulic rod and a limiting ring: the main body end of the hydraulic rod is fixedly connected to the outer surface of one set of wheel components; the limiting rings are in two sets. Its key technical features are: it can fine-tune the direction of the shield tunneling machine wheel assembly, is convenient to use, has good performance, the wheel body can quickly return to center, and it allows operators to easily adjust the direction of the housing using the equipment, thereby adjusting the direction of the wheel body and thus facilitating the adjustment of the shield tunneling machine's movement direction. This makes shield tunneling machine direction adjustment convenient and has good application prospects.

Description

Technical Field

[0001] This invention belongs to the field of tunnel boring machines, specifically an angle-adjustable, stable tunnel boring machine wheel assembly. Background Technology

[0002] Tunnels are engineering structures buried underground, representing a form of human utilization of underground space. Tunnels can be categorized into traffic tunnels, hydraulic tunnels, municipal tunnels, mining tunnels, and military tunnels.

[0003] A tunnel boring machine (TBM) is a type of tunnel boring machine that uses the shield tunneling method. The shield tunneling method involves the TBM simultaneously constructing (laying) the tunnel's "shield" (referring to supporting segments) while excavating, which differs from open-face construction methods.

[0004] The basic working principle of a tunnel boring machine is that a cylindrical steel component advances along the tunnel axis while excavating the soil.

[0005] The shell of this cylindrical component, also known as the shield, serves as temporary support for the excavated, unlined tunnel section, bearing the pressure of the surrounding soil layers and sometimes groundwater pressure, while also keeping groundwater out. Excavation, soil removal, and lining operations are carried out under the protection of the shield.

[0006] The tunnel boring machine has many structures, including the wheel assembly installed at the bottom of the machine to support it.

[0007] Currently, the wheels used by tunnel boring machines on the market are of the traditional type, that is, the vehicle body is directly fixed to the wheels, and the wheels move along the track when in use;

[0008] As can be seen from the above, the wheels of tunnel boring machines on the market currently move in only one direction, making directional adjustment very inconvenient.

[0009] However, when in use, the tunnel boring machine is subjected to force and is prone to deviation, requiring real-time adjustment, which is quite troublesome and does not meet people's usage requirements. To address this, people invented a stabilized tunnel boring machine wheel assembly with adjustable angle. Summary of the Invention

[0010] To overcome the shortcomings of the prior art, this application provides an angle-adjustable, stable shield machine wheel assembly, which includes an angle adjustment component. Two sets of wheel components are movably connected by a connecting component. When in use, the angle adjustment component is activated, which can adjust the direction of the wheel component near the front end of the shield machine, causing the wheel component to shift. This allows for fine-tuning of the direction of the shield machine wheel assembly, making it convenient to use, effective, and promising for future applications.

[0011] The technical solution adopted to address the detection problem is:

[0012] An angle-adjustable, stable shield tunneling machine wheel assembly includes wheel components, a connecting assembly, and an angle adjustment assembly.

[0013] The number of wheel components is two sets;

[0014] The two sets of wheel components are movably connected by a connecting assembly;

[0015] The angle adjustment assembly is connected to two sets of wheel components and is used to adjust the direction of the wheel components.

[0016] The angle adjustment assembly includes a hydraulic rod and a limiting ring.

[0017] The main body end of the hydraulic rod is fixedly connected to the outer surface of one of the sets of wheel components;

[0018] There are two sets of limiting rings. The two sets of limiting rings are fixedly connected to the telescopic end of the hydraulic rod and the outer surface of another set of wheel components, respectively, and the two sets of limiting rings are interlocked.

[0019] Two sets of wheel components are arranged in a row. When in use, the front wheel components are close to the front of the tunnel boring machine and are subjected to greater force, which may cause a slight deviation in direction. At this time, the hydraulic rod in the angle adjustment component applies pressure to the front wheel components, thereby correcting the direction of the wheel components and achieving good results.

[0020] This invention discloses an angle-adjustable, stable shield tunneling machine wheel assembly, which includes an angle adjustment component. Two sets of wheel components are movably connected by a connecting component. When in use, the angle adjustment component is activated, which can adjust the direction of the wheel component near the front end of the shield tunneling machine, causing the wheel component to shift. This allows for fine-tuning of the direction of the shield tunneling machine wheel assembly. It is convenient to use, has good performance, and has promising application prospects.

[0021] Preferably, the connecting component includes a connecting strip and a limiting pin:

[0022] There are two sets of connecting strips, and the two sets of connecting strips are respectively fixedly installed on two sets of wheel components;

[0023] The two sets of connecting strips are rotatably connected by a limiting pin.

[0024] The connecting component serves as a limit, facilitating the application of pressure by the angle adjustment component.

[0025] The connecting components can also be replaced by other existing connecting structures that have the same effect.

[0026] Preferably, the wheel component includes a housing portion and a wheel body, the wheel body being rotatably mounted inside the housing portion via a pin.

[0027] The housing serves to protect the wheels.

[0028] Preferably, the number of wheels is two sets, and the wheels are rubber-coated wheels.

[0029] The wheel body is formed by combining two sets of rubber-coated wheels, which increases the bearing area, stabilizes the trolley, and reduces noise during rolling, resulting in good performance.

[0030] Preferably, a limiting component that limits the movement of the tunnel boring machine track is provided at the middle position of the outer surface of the wheel body.

[0031] The setting of the limit component can stabilize the wheel and prevent the wheel from deviating, which can effectively improve the stability of the wheel movement and has a good effect.

[0032] Preferably, the limiting component includes an annular groove and an annular guide groove:

[0033] The annular groove is located in the middle of the outer surface of the wheel body;

[0034] There are two sets of annular guide grooves, which are located at both ends of the annular groove and are opened on the outer surface of the wheel body.

[0035] The bottom surface of the annular guide groove is inclined, and the annular guide groove is connected to the annular groove.

[0036] When the track contacts the annular guide groove, the wheel assembly moves forward or backward, and the wheel body is subjected to force, causing the annular groove to directly connect with the track, ensuring the stability of the wheel body's movement and resulting in good performance.

[0037] This invention discloses an angle-adjustable, stable shield tunneling machine wheel assembly, which includes a limiting component. In use, the annular groove on the wheel body cooperates with the track to limit the position of the wheel body and prevent it from deviating from the direction. The annular guide groove can be used in conjunction with the angle adjustment component. When the wheel body position deviates, the angle adjustment component changes the wheel body angle, causing the annular guide groove to contact the track, thereby enabling the wheel body to quickly return to the correct position. It is convenient to use and has good application prospects.

[0038] Preferably, cleaning components for cleaning the tunnel boring machine track are fixedly installed on both sides of the outer surface of the housing near the lower end.

[0039] During use, the cleaning component contacts the upper surface of the tunnel boring machine track. As the wheels move, they come into contact with the track, pushing away debris from the track and preventing it from affecting the operation of the wheels. This method is effective.

[0040] Preferably, the cleaning assembly includes a fixing strip and a cleaning strip:

[0041] The fixing strip is fixedly installed on the outer surface of the housing near the lower end;

[0042] The cleaning strip is fixedly installed on the lower end face of the fixing strip, and the lower end face of the cleaning strip is in contact with the outer surface of the tunnel boring machine track.

[0043] When in use, the cleaning strip contacts the outer surface of the tunnel boring machine track, pushing away debris from the track surface and keeping it away from the wheels, thus ensuring the smooth operation of the wheels.

[0044] Preferably, a hydraulic column is provided at the middle position inside the housing, and a support plate is rotatably mounted on the telescopic end of the hydraulic column. Through holes are provided on the outer surface of the support plate near the four corners.

[0045] Preferably, a number of limiting posts are fixedly installed on the lower end face of the support plate near the outer side, and the number of limiting posts are arranged in a ring. A number of limiting holes are opened on the upper end face of the housing part, and the lower end of the limiting post is inserted into the limiting hole. Support posts for supporting the support plate are fixedly installed on the upper end face of the housing part near the four corners.

[0046] The support columns serve to assist in supporting the support plates and prevent the hydraulic columns from being subjected to excessive stress.

[0047] The lower end of the limiting post is inserted into the limiting hole, thereby limiting the direction of the support plate, which can improve stability and has a good effect.

[0048] When a turn is required, the hydraulic column is activated, which lifts and changes the height of the support plate, causing the limit hole to separate from the limit hole. This creates space for movement between the shell and the main body of the tunnel boring machine, allowing staff to easily adjust the direction of the shell, which in turn adjusts the direction of the wheels, thus facilitating the direction of the tunnel boring machine's movement.

[0049] This invention describes an angle-adjustable, stable shield tunneling machine wheel assembly, comprising a hydraulic column, a support plate, and a limiting column. These three components work together to activate when the direction of the shield tunneling machine's movement is adjusted. The hydraulic column lifts, changing the height of the support plate, creating a space for movement between the housing and the main body of the shield tunneling machine. This allows operators to easily adjust the direction of the housing, thereby adjusting the direction of the wheels and ultimately the direction of the shield tunneling machine's movement. This makes shield tunneling machine direction adjustment convenient, provides good performance, and has promising application prospects.

[0050] In summary, the present invention has at least one of the following beneficial technical effects:

[0051] Firstly, this invention describes an angle-adjustable, stable shield machine wheel assembly, which includes an angle adjustment component. Two sets of wheel components are movably connected by a connecting component. When in use, the angle adjustment component is activated, which can adjust the direction of the wheel component near the front end of the shield machine, causing the wheel component to shift. This allows for fine-tuning of the direction of the shield machine wheel assembly. It is convenient to use, has good performance, and has promising application prospects.

[0052] Secondly, this invention describes an angle-adjustable, stable shield tunneling machine wheel assembly, which includes a limiting component. In use, the annular groove on the wheel body cooperates with the track to limit the position of the wheel body and prevent it from deviating from the direction. The annular guide groove can be used in conjunction with the angle adjustment component. When the wheel body position deviates, the angle adjustment component changes the wheel body angle, causing the annular guide groove to contact the track, thereby enabling the wheel body to quickly return to the correct position. It is convenient to use and has good application prospects.

[0053] Thirdly, this invention describes an angle-adjustable, stable shield machine wheel assembly, which includes a hydraulic column, a support plate, and a limiting column. These three components work together and are activated when the direction of the shield machine's movement is adjusted. The hydraulic column lifts and changes the height of the support plate, creating a space for movement between the housing and the shield machine body. This allows workers to easily adjust the direction of the housing, thereby adjusting the direction of the wheels and ultimately the direction of the shield machine's movement. This makes shield machine direction adjustment convenient, has good performance, and shows promising application prospects. Attached Figure Description

[0054] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0055] Figure 2 This is a partial structural diagram of the present invention;

[0056] Figure 3 This is a structural diagram of the wheel component in this invention;

[0057] Figure 4 This is a partial structural diagram of the wheel component in this invention;

[0058] Figure 5 This is a partial structural diagram of the wheel body in this invention;

[0059] Figure 6 This is a structural diagram of the support plate in this invention.

[0060] Reference numerals in the attached drawings: 1. Wheel component; 2. Hydraulic rod; 3. Limiting ring; 4. Connecting strip; 5. Limiting pin; 6. Wheel body; 7. Annular groove; 8. Annular guide groove; 9. Fixing strip; 10. Cleaning strip; 11. Hydraulic column; 12. Support plate; 13. Limiting post; 14. Support post. Detailed Implementation

[0061] This application provides an adjustable-angle, stable shield machine wheel assembly, which solves the problem that the wheels used in shield machines currently on the market are of the traditional type, that is, the vehicle body is directly fixed to the wheel, and the wheel moves along the track during use. As can be seen from the above, the direction of movement of shield machine wheels on the market is singular, and the direction adjustment is very inconvenient. In addition, when the shield machine is under force, it is easy to deviate, which requires real-time adjustment, making it cumbersome to use.

[0062] This patent describes an angle adjustment component in an adjustable and stable shield machine wheel assembly. Two sets of wheels are movably connected by a connecting component. When in use, the angle adjustment component is activated, which can adjust the direction of the wheel near the front end of the shield machine, causing the wheel to shift. This allows for fine-tuning of the direction of the shield machine wheel assembly. It is convenient to use, has good performance, and has promising application prospects.

[0063] This invention discloses an angle-adjustable, stable shield tunneling machine wheel assembly, which includes a limiting component. In use, the annular groove on the wheel body cooperates with the track to limit the position of the wheel body and prevent it from deviating from the direction. The annular guide groove can be used in conjunction with the angle adjustment component. When the wheel body position deviates, the angle adjustment component changes the wheel body angle, causing the annular guide groove to contact the track, thereby enabling the wheel body to quickly return to the correct position. It is convenient to use and has good application prospects.

[0064] This invention describes an angle-adjustable, stable shield tunneling machine wheel assembly, comprising a hydraulic column, a support plate, and a limiting column. These three components work together to activate when the direction of the shield tunneling machine's movement is adjusted. The hydraulic column lifts, changing the height of the support plate, creating a space for movement between the housing and the main body of the shield tunneling machine. This allows operators to easily adjust the direction of the housing, thereby adjusting the direction of the wheels and ultimately the direction of the shield tunneling machine's movement. This makes shield tunneling machine direction adjustment convenient, provides good performance, and has promising application prospects.

[0065] Example 1:

[0066] An angle-adjustable, stable shield tunneling machine wheel assembly, such as Figures 1-6 As shown, it includes wheel component 1, connecting assembly, and angle adjustment assembly:

[0067] The number of wheel components 1 is two sets;

[0068] The two sets of wheel components 1 are movably connected by a connecting assembly;

[0069] An angle adjustment assembly is connected to two sets of wheel components 1, and the angle adjustment assembly is used to adjust the direction of the wheel components 1.

[0070] The angle adjustment assembly includes a hydraulic rod 2 and a limit ring 3.

[0071] The main body end of the hydraulic rod 2 is fixedly connected to the outer surface of one of the sets of wheel components 1;

[0072] There are two sets of limiting rings 3. The two sets of limiting rings 3 are fixedly connected to the telescopic end of the hydraulic rod 2 and the outer surface of another set of wheel parts 1, respectively. The two sets of limiting rings 3 are interlocked.

[0073] Two sets of wheel components 1 are arranged in a row. When in use, the front wheel components are close to the front of the tunnel boring machine and are subjected to greater force, which may cause a slight deviation in direction. At this time, the hydraulic rod 2 in the angle adjustment component applies pressure to the front wheel component 1, thereby correcting the direction of the wheel component 1 and achieving good results.

[0074] This invention describes an angle-adjustable, stable shield tunneling machine wheel assembly. It includes an angle adjustment component, in which two sets of wheel components 1 are movably connected by a connecting component. When in use, the angle adjustment component is activated, which can adjust the direction of the wheel component 1 near the front end of the shield tunneling machine, causing the wheel component 1 to deflect. This allows for fine-tuning of the direction of the shield tunneling machine wheel assembly. It is convenient to use, has good performance, and has promising application prospects.

[0075] Example 2:

[0076] Based on Example 1, such as Figures 1-6 As shown, this embodiment illustrates the main structure of the connecting component;

[0077] The connecting components include connecting strip 4 and limit pin 5:

[0078] There are two sets of connecting strips 4, and the two sets of connecting strips 4 are respectively fixedly installed on the two sets of wheel parts 1;

[0079] The two sets of connecting strips 4 are rotatably connected by a limit pin 5.

[0080] The connecting component serves as a limit, facilitating the application of pressure by the angle adjustment component.

[0081] The connecting components can also be replaced by other existing connecting structures that have the same effect.

[0082] The wheel component 1 includes a housing part and a wheel body 6, with the wheel body 6 rotatably mounted inside the housing part via a pin.

[0083] The housing serves to protect wheel 6.

[0084] There are two sets of wheel bodies 6, and the wheel bodies 6 are rubber-coated wheels.

[0085] Wheel body 6 is formed by combining two sets of rubber-coated wheels, which increases the bearing area, stabilizes the trolley, and reduces noise during rolling, resulting in good performance.

[0086] A limiting component that is limited to the tunnel boring machine track is provided at the middle position of the outer surface of the wheel body 6.

[0087] The setting of the limit component can stabilize wheel 6 and prevent wheel 6 from deviating, which can effectively improve the stability of wheel 6 movement and has a good effect.

[0088] The limiting component includes an annular groove 7 and an annular guide groove 8:

[0089] The annular groove 7 is formed in the middle of the outer surface of the wheel body 6;

[0090] There are two sets of annular guide grooves 8, which are located at both ends of annular groove 7 and are opened on the outer surface of wheel body 6.

[0091] The bottom surface of the annular guide groove 8 is inclined, and the annular guide groove 8 is connected to the annular groove 7.

[0092] When the track contacts the annular guide groove 8, the wheel assembly moves forward or backward, and the wheel body 6 is subjected to force, so that the annular groove 7 directly connects with the track, ensuring the stability of the wheel body 6's movement and achieving good performance.

[0093] This invention discloses an angle-adjustable, stable shield tunneling machine wheel assembly, which includes a limiting component. In use, the annular groove 7 on the wheel body 6 cooperates with the track to limit the position of the wheel body 6 and prevent it from deviating from the direction. The annular guide groove 8 can be used in conjunction with the angle adjustment component. When the position of the wheel body 6 deviates, the angle adjustment component can change the angle of the wheel body 6, so that the annular guide groove 8 contacts the track, thereby allowing the wheel body 6 to quickly return to the correct position. It is convenient to use and has good application prospects.

[0094] Example 3:

[0095] Based on Example 2, such as Figures 1-6 As shown, this embodiment illustrates the main structure of the cleaning component;

[0096] Cleaning components for cleaning the tunnel boring machine track are fixedly installed on both sides of the lower end of the outer surface of the shell.

[0097] When in use, the cleaning component contacts the upper surface of the tunnel boring machine track. The wheel component 1 will contact the track during movement, which can push away the debris on the track and prevent the debris from affecting the operation of the wheel component 1. The effect is good.

[0098] The cleaning components include a fixing strip 9 and a cleaning strip 10:

[0099] The fixing strip 9 is fixedly installed on the outer surface of the housing near the lower end;

[0100] The cleaning strip 10 is fixedly installed on the lower end face of the fixing strip 9, and the lower end face of the cleaning strip 10 is in contact with the outer surface of the tunnel boring machine track.

[0101] When in use, the cleaning strip 10 contacts the outer surface of the tunnel boring machine track, pushing away debris from the outer surface of the tunnel boring machine track and keeping the debris away from the wheel body 6, thereby ensuring the operation of the wheel body 6 and making the movement of the wheel body 6 more stable.

[0102] A hydraulic column 11 is provided in the middle of the interior of the housing. A support plate 12 is rotatably mounted on the telescopic end of the hydraulic column 11. Through holes are provided on the outer surface of the support plate 12 near the four corners.

[0103] Several sets of limiting posts 13 are fixedly installed on the lower end face of the support plate 12 near the outer side. The sets of limiting posts 13 are arranged in a ring. Several sets of limiting holes are opened on the upper end face of the shell. The lower end of the limiting post 13 is inserted into the limiting hole. Support posts 14 that support the support plate 12 are fixedly installed on the upper end face of the shell near the four corners.

[0104] The support column 14 serves to assist in supporting the support plate 12, preventing the hydraulic column 11 from being subjected to excessive force.

[0105] The lower end of the limiting post 13 is inserted into the limiting hole, thereby limiting the direction of the support plate 12, which can improve stability and has a good effect.

[0106] When a turn is required, the hydraulic column 11 is activated. The hydraulic column 11 lifts and changes the height of the support plate 12, causing the limit hole to separate from the limit hole. This creates space for movement between the shell and the main body of the tunnel boring machine, allowing workers to easily adjust the direction of the shell using the equipment. This, in turn, allows for the adjustment of the direction of the wheel 6, and thus facilitates the adjustment of the tunnel boring machine's direction of movement.

[0107] This invention describes an angle-adjustable, stable shield tunneling machine wheel assembly, comprising a hydraulic column 11, a support plate 12, and a limiting column 13. These three components work together and are activated when the direction of the shield tunneling machine's movement is adjusted. The hydraulic column 11 lifts, changing the height of the support plate 12, creating a space for movement between the housing and the main body of the shield tunneling machine. This allows operators to easily adjust the direction of the housing, thereby adjusting the direction of the wheel 6 and ultimately the direction of the shield tunneling machine's movement. This makes shield tunneling machine direction adjustment convenient, provides good performance, and has promising application prospects.

[0108] It should be noted that, in the present invention, an angle-adjustable stable shield machine wheel assembly is used such that two sets of wheel components 1 are arranged in a row. The front wheel assembly is close to the front section of the shield machine and is subjected to greater force, which may cause a slight deviation in direction. At this time, the hydraulic rod 2 in the angle adjustment assembly applies pressure to the front wheel component 1, thereby correcting the direction of the wheel component 1.

[0109] When in use, the track is located inside the annular groove 7 and contacts the inner bottom surface of the annular groove 7, thereby ensuring the stability of the movement of the wheel 6;

[0110] When the position of wheel 6 deviates, the angle adjustment component changes the angle of wheel 6, so that the annular guide groove 8 contacts the track, thereby enabling wheel 6 to quickly return to the correct position.

[0111] Finally, it should be noted that the above embodiments are merely examples for clearly illustrating the present invention and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. An angle-adjustable, stable shield tunneling machine wheel assembly, characterized in that, include: Wheel components (1), which are in two sets; The two sets of wheel components (1) are movably connected by the connecting assembly; An angle adjustment assembly is connected to two sets of wheel components (1) and is used to adjust the direction of the wheel components (1); The angle adjustment component includes: The hydraulic rod (2) has its main body end fixedly connected to the outer surface of one of the sets of wheel components (1); The limiting rings (3) are in two sets. The two sets of limiting rings (3) are fixedly connected to the telescopic end of the hydraulic rod (2) and the outer surface of another set of wheel parts (1), respectively. The two sets of limiting rings (3) are interlocked. The connection component includes: The connecting strip (4) is in two sets, and the two sets of connecting strip (4) are respectively fixedly installed on the two sets of wheel parts (1); The two sets of connecting strips (4) are rotatably connected by the limiting pin (5).

2. The adjustable-angle, stable shield tunneling machine wheel assembly as described in claim 1, characterized in that: The wheel component (1) includes a housing and a wheel body (6), the wheel body (6) being rotatably mounted inside the housing via a pin.

3. The adjustable-angle, stable shield tunneling machine wheel assembly as described in claim 2, characterized in that: The number of the wheel body (6) is two sets, and the wheel body (6) is a rubber-coated wheel.

4. The adjustable-angle, stable shield tunneling machine wheel assembly as described in claim 3, characterized in that: The outer surface of the wheel (6) is provided with a limiting component that limits the tunnel boring machine track.

5. The adjustable-angle, stable shield tunneling machine wheel assembly as described in claim 4, characterized in that: The limiting component includes: An annular groove (7) is formed in the middle of the outer surface of the wheel body (6); Annular guide grooves (8) are provided in two sets at both ends of annular grooves (7) and are opened on the outer surface of wheel body (6). The bottom surface of the annular guide groove (8) is inclined, and the annular guide groove (8) is connected to the annular groove (7).

6. The adjustable-angle, stable shield tunneling machine wheel assembly as described in claim 5, characterized in that: Cleaning components for cleaning the tunnel boring machine track are fixedly installed on both sides of the outer surface of the housing near the lower end.

7. The adjustable-angle, stable shield tunneling machine wheel assembly as described in claim 6, characterized in that: The cleaning component includes: The fixing strip (9) is fixedly installed on the outer surface of the housing near the lower end; The cleaning strip (10) is fixedly installed on the lower end face of the fixing strip (9), and the lower end face of the cleaning strip (10) is in contact with the outer surface of the tunnel boring machine track.

8. The adjustable-angle, stable shield tunneling machine wheel assembly as described in claim 7, characterized in that: A hydraulic column (11) is provided in the middle of the interior of the housing. A support plate (12) is rotatably installed on the telescopic end of the hydraulic column (11). Through holes are provided on the outer surface of the support plate (12) near the four corners.

9. The adjustable-angle, stable shield tunneling machine wheel assembly as described in claim 8, characterized in that: Several sets of limiting posts (13) are fixedly installed on the lower end face of the support plate (12) near the outer side. The several sets of limiting posts (13) are arranged in a ring. Several sets of limiting holes are opened on the upper end face of the shell part. The lower end of the limiting post (13) is inserted into the limiting hole. Support posts (14) that support the support plate (12) are fixedly installed on the upper end face of the shell part near the four corners.

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