bottom shell structure

Abstract

The application relates to a bottom shell structure, which comprises a shell with an open side, a connecting column arranged in the shell, the connecting column being axially hollow and having an end directed to the open side of the shell, and a plurality of mounting positions arranged on the side of the connecting column, the mounting positions being used for mounting connecting members with threaded holes, when the connecting members are mounted in any of the mounting positions, the threaded holes of the connecting members all overlap with or are in the through holes formed by the axial hollow of the connecting column, so that screws can be directly inserted into the connecting column and connected and locked with the connecting members; when any of the mounting positions is damaged due to repeated use or external force, other unused mounting positions can be selected to continue mounting the connecting members, so that the locking function is not affected.

Description

Technical Field

[0001] This application relates to the field of panel mounting technology, and more particularly to a bottom shell structure. Background Technology

[0002] The mounting box, also known as the base shell, is widely used for installing and fixing components such as indoor unit control panels, smart gateways, and sensor modules, such as the 86 base shell (standard 86-type base box). In traditional structures, the base shell is usually made of injection-molded plastic with several screw posts inside for connection to the panel or mounting bracket via screws. However, in actual use, especially during after-sales maintenance, equipment upgrades, or frequent disassembly and assembly, the screw posts, due to repeated tightening and loosening, are subjected to cyclic shear and tensile stresses, making them prone to material fatigue and plastic deformation, ultimately leading to cracking or complete breakage at the root of the screw posts. Such problems not only affect product reliability but also increase after-sales costs and the risk of customer complaints. Existing solutions mostly involve increasing material strength or thickening the screw posts, but due to limitations in structural space, injection molding processes, and cost control, it is difficult to fundamentally solve the problem of "aging and cracking after repeated use." Utility Model Content

[0003] This application provides a bottom shell structure to solve the problem of screw mounting posts easily stripping screws after repeated screwing or aging.

[0004] In a first aspect, this application provides a bottom shell structure, including: a shell with an opening on one side, a connecting column disposed within the shell, the connecting column being axially hollow and its end facing the opening side of the shell, the connecting column having a plurality of mounting positions on its side, the mounting positions being used to mount connectors with threaded holes, and when the connector is mounted in any mounting position, its threaded hole overlaps with or is within the through hole formed by the axially hollow connecting column.

[0005] Furthermore, the mounting position is a mounting groove provided on the side of the connecting column, the mounting groove communicating with the hollow part of the connecting column, so that the connector installed in the mounting position is coaxial with the connecting column and is limited.

[0006] Furthermore, the width between the two inner walls of the mounting groove parallel to the axis of the connecting column is greater than the diameter of the through hole formed in the hollow part of the connecting column, and the width of the connector is adapted to the width between the two inner walls of the mounting groove parallel to the axis of the connecting column.

[0007] Furthermore, the through hole formed in the hollow connecting column passes through the two inner walls of the mounting groove that are perpendicular to the axis of the connecting column, and the edge of the through hole is inside the edge of the two inner walls that are perpendicular to the axis of the connecting column.

[0008] Preferably, the connector is a hexagonal nut, and the bottom of the mounting groove is adapted to the hexagonal nut in a V-shape.

[0009] Furthermore, the mounting positions are evenly spaced along the axial direction of the connecting column.

[0010] Furthermore, multiple connecting columns are provided, symmetrically distributed within the housing and close to the inner wall of the housing.

[0011] Furthermore, two connecting columns are provided and are located near the inner walls of the left and right sides of the housing, and the opening of the mounting groove faces the inner wall of the upper side of the housing.

[0012] Furthermore, the connecting column has a pin hole on the side facing each of the slots that communicates with the mounting slot.

[0013] Furthermore, the connecting column is connected to the inner wall of the housing by reinforcing ribs.

[0014] The technical solutions provided in this application have the following advantages compared with the prior art: This application embodiment features multiple mounting positions spaced axially along the outer side of the connecting column of the base shell. Each mounting position is used to install a connector with a threaded hole. When the connector is installed in any mounting position, its threaded hole overlaps with or is located within the through hole formed by the axial hollow structure of the connecting column, allowing the screw to directly extend into the connecting column and connect and lock with the connector. When a mounting position is damaged due to repeated use or external force, other unused mounting positions can be selected to continue installing the connector, ensuring that the locking function is not affected. Moreover, the connector itself can be replaced individually when damaged, without affecting the overall structure of the shell and the connecting column, thus avoiding the problems of stripping or difficulty in tightening due to plastic aging caused by screws being directly screwed into the plastic structure in traditional base shells. By setting an axially hollow connecting column and a replaceable mounting position and connector structure, stable locking and convenient maintenance of the base shell are achieved during long-term use, improving installation reliability and extending the service life of the structure. Attached Figure Description

[0015] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0016] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] One or more embodiments are illustrated by way of example with reference numerals in the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Elements with the same reference numerals in the drawings are denoted as similar elements. Unless otherwise stated, the figures in the drawings are not to be limited by scale.

[0018] Figure 1 This is a schematic diagram of a prior art embodiment; Figure 2 This is a structural schematic diagram of a further embodiment of the prior art; Figure 3 This is a three-dimensional structural diagram of the connector before assembly in the embodiments of this application; Figure 4 This is a schematic diagram of the planar structure of the connector before assembly in the embodiments of this application; Figure 5 for Figure 4 A magnified view of a portion of the image; Figure 6 This is a three-dimensional structural diagram of the connector after assembly in the embodiments of this application; Figure 7 This is a cross-sectional view of the connector after assembly in an embodiment of this application; Figure 8 for Figure 7 A magnified view of a portion of the image; Explanation of reference numerals in the attached figures: 6. Shell; 7. Connecting post; 71. Through hole; 72. Mounting position; 8. Connectors; 9. Connecting reinforcement bars. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0020] The following disclosure provides numerous different embodiments or examples for implementing various structures of this application. To simplify the disclosure, specific examples of components and arrangements are described below. These are merely examples and are not intended to limit the scope of this application. Furthermore, reference numerals and / or letters may be repeated in different examples. Such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed.

[0021] For ease of description, spatial relative terms may be used in the text to describe the relative position or movement of one element or feature relative to another element or feature, as shown in the figure. These relative terms include, for example, "inside," "outside," "middle," "outer," "below," "below," "above," "front," "back," etc. Such spatial relative terms are intended to include different orientations of the device in use or operation, other than those depicted in the figure. For example, if the device in the figure undergoes a positional flip, orientation change, or change of motion, these directional indications will change accordingly. For instance, an element described as "below other elements or features" or "below other elements or features" will subsequently be oriented "above other elements or features" or "above other elements or features." Therefore, the example term "below" can include both upper and lower orientations. The device may be otherwise oriented (rotated 90 degrees or in other directions), and the spatial relative descriptors used in the text will be interpreted accordingly.

[0022] To address the issue of stripped screw threads after repeated screw insertion on the mounting posts of the base shell, or difficulty in tightening due to plastic aging, existing technology discloses a repairable junction box and its repair components. The junction box consists of a box body 1 and screw posts 2. The screw posts 2 are located on the two inner sides of the box body 1. The junction box has clips 4 to prevent loosening after installation and wire passage holes 5. The inner wall of the box body 1 has four corner bosses 3, each boss 3 having a groove 3-1 for installing and securing the repair components. Figure 2 As shown, in order to further improve the performance of the repair parts and prevent them from falling off, a boss 3 can be provided on the inner wall of the box 1 above the first threaded hole end face of the screw post 2.

[0023] While the aforementioned prior art can also solve the problem of screw mounting posts easily stripping screws after repeated screw insertion or becoming difficult to tighten after aging, it requires the addition of a repair component inside the junction box. This repair component is fixed by a slot on the boss. As can be seen from the attached diagram, this repair component is relatively large, and even if the repair component is replaced, it is fixed by the same slot in the same position. Repeated use of the slot may cause damage, and the repair component occupies space inside the junction box, which may also cause interference when installing large components such as control panels.

[0024] To address the technical problems in the prior art, this application provides a bottom shell structure that solves the problem of stripped screws after repeated screw insertion on the bottom shell screw mounting post, and avoids the difficulty in tightening after plastic aging. Furthermore, it does not occupy internal installation space in the bottom shell, making installation simple and convenient.

[0025] Figure 3As shown, this application provides a bottom shell structure. The bottom shell structure is installed on a wall or panel and can be used for the fixed installation of components such as indoor unit control panels, smart gateways, sensor modules, and socket switches. Specifically, the bottom shell structure includes a housing 6 and a connecting column 7. One side of the housing 6 has an opening in the form of a concave cavity to accommodate the component to be installed, and it can be installed in a pre-set groove on the wall or panel, with the opening facing outwards. The connecting column 7 is provided inside the housing 6 for use with screws to fix the component to be installed. The connecting column 7 has an axially hollow structure (e.g., ...). Figure 4 , 5 As shown, a countersunk hole structure can be adopted to facilitate the installation of screws. The end faces the opening side of the housing 6, which makes it easy for the screw to be inserted from the opening direction for positioning.

[0026] Multiple mounting positions 72 are provided axially at intervals on the outer side of the connecting column 7. Each mounting position 72 is used to install the connector 8 with a threaded hole. When the connector 8 is installed in any mounting position 72, its threaded hole overlaps with or is located in the through hole 71 formed by the axial hollow structure of the connecting column 7, so that the screw can directly pass through the connecting column 7 and be locked in the connector 8.

[0027] When a mounting position 72 is damaged due to repeated use or external force, other unused mounting positions 72 can be selected to continue installing the connector 8, ensuring the locking function remains unaffected. Furthermore, if the connector 8 itself is damaged, it can be replaced individually without affecting the overall structure of the housing 6 and the connecting column 7. This avoids the problems of stripping screws or difficulty in tightening due to plastic aging caused by directly screwing screws into the plastic structure in traditional base shells. In other words, by setting up an axially hollow connecting column 7 and replaceable mounting positions 72 and connector 8, stable locking and convenient maintenance of the base shell are achieved during long-term use, improving installation reliability and extending the structural service life.

[0028] In the embodiments of this application, a mounting groove for mounting the connector 8 is provided on the side of the connecting post 7. The mounting groove is a partially recessed structure opened along the side wall of the connecting post 7, and the direction of the recess is perpendicular to the axial direction of the connecting post 7, that is, it is recessed inward at the radial side wall position.

[0029] The mounting slot and the hollow channel of the connecting post 7 are connected, so that after the connector 8 is inserted into the mounting slot, its threaded hole and the through hole 71 formed by the hollow channel are coaxial. That is, the threaded hole overlaps with the through hole 71 formed by the axial hollow of the connecting post 7, or the threaded hole is located within the range of the through hole 71. After the connector 8 is inserted into the mounting slot, it is locked by a screw in the opening direction of the housing 6. When the screw is screwed into the connector 8 through the hollow channel of the connecting post 7, the screw head presses the connector 8 against the side of the mounting slot, so that the connector 8 is automatically limited while being locked, preventing radial and axial displacement.

[0030] The mounting slot structure facilitates the replacement of the connector 8 between different mounting positions 72. When the connector 8 or hole at a certain mounting slot is damaged, the connector 8 can be directly replaced or moved to an adjacent mounting slot for continued use without the need to repair or scrap the bottom shell. Because the recessed direction of the mounting slot is perpendicular to the axis of the connecting post 7, the connector 8 will not interfere with the screw-in path when inserted, and it also avoids occupying the assembly space in the opening direction of the housing 6 during installation or replacement. Furthermore, the machining of the mounting slot is simpler and more convenient.

[0031] In a specific embodiment, an installation width for accommodating the connector 8 is provided between the inner walls on both sides of the mounting groove parallel to the axis of the connecting column 7. This width is greater than the diameter of the through hole 71 formed by the hollow channel in the connecting column 7. At the same time, the width of the connector 8 body matches the width of the mounting groove in this direction, so that the connector 8 can be limited and fitted between the two inner walls after being inserted into the mounting groove.

[0032] Because the lateral width of the mounting groove is greater than the diameter of the through hole 71, the screw will not be affected by the groove wall or the positional displacement of the connector 8 when it is screwed into the connector 8 through the through hole 71. At the same time, the connector 8 has sufficient assembly space within the mounting groove. The width of the connector 8 is adapted to the spacing between the inner walls of the mounting groove, so that once the connector 8 is tightened by the screw, it is pressed against the inner wall of the mounting groove and will not wobble or shift axially within the range of the through hole 71.

[0033] This structure ensures a reliable locking relationship between the connector 8 and the screw: during screw tightening, the connector 8 is limited by the two inner walls of the mounting groove, preventing it from being pulled into the hollow through hole 71 by the screw's pushing force, and also preventing rotation or misalignment during screw tightening. Even when replacing the connector 8 between different mounting positions 72, there is no need to adjust the groove width or reposition the hole. Through the matching design of the mounting groove width and the connector 8 width, stable positioning of the connector 8 and axial fixing during screw tightening are achieved, preventing the connector 8 from falling off, shifting, or getting stuck inside the through hole 71, thus improving the overall installation reliability and service life of the base shell.

[0034] In specific embodiments, such as Figures 6 to 8As shown, the through hole 71 formed by the axial hollow of the connecting post 7 passes through the corresponding two side walls of the mounting groove. When the through hole 71 passes through the mounting groove area, it communicates with a pair of opposing inner walls in the vertical direction of the connecting post 7 in the mounting groove, allowing the screw to pass directly through the through hole 71 and mate with the connector 8 installed there. The edge position of the through hole 71 is limited to within the edges of the aforementioned two side inner walls, that is, the opening of the through hole 71 does not exceed the range of the inner wall of the mounting groove in the vertical direction, but is embedded within this range. This ensures that after the connector 8 (such as a nut, metal insert, or other standard internal threaded hole part, and the screw is also a standard screw, such as M3) is placed in the mounting groove, its threaded hole can completely align with the axis of the through hole 71, and the assembly will not be affected by the boundary deviation of the through hole 71.

[0035] By confining the through hole 71 within the inner edge of the corresponding sidewall of the mounting groove, the coaxiality and strength of the screw tightening path are ensured, while also allowing the mounting groove to be compatible with conventional connectors 8. This facilitates assembly, replacement, and maintenance, reduces manufacturing costs, and improves versatility. Specifically, since the width, diameter, and opening position of the through hole 71 are all within the edges of the inner walls on both sides of the mounting groove, the connector 8 can adopt a commonly used standard part structure. For example, ordinary hexagonal nuts, round nuts, embedded fasteners, or threaded sleeves can be directly used as connectors 8, inserted into the mounting groove, and corresponding to the through hole 71. The standard connector 8 will not protrude beyond the mounting groove, nor will the limiting effect be affected by the outward expansion of the through hole 71.

[0036] In the specific embodiments of this application, such as Figure 8 As shown, connector 8 can be in the form of a hexagonal nut for locking with the screw. To ensure stable positioning of the hexagonal nut within the mounting groove and prevent rotation, the bottom of the mounting groove is designed with a V-shape that matches the shape of the hexagonal nut. The V-shaped bottom can be formed by two inclined surfaces, the inclination angle of which matches the corner shape of the hexagonal nut, allowing the nut to be automatically positioned through geometric contact after being placed in the mounting groove. One corner or two adjacent sides of the hexagonal nut can rest against the inclined surface of the V-shaped groove bottom, preventing the nut from rotating or slipping laterally when tightening the screw.

[0037] The V-shaped groove bottom not only limits the radial movement of the nut but also creates a wedging effect under the screw tightening force, ensuring a more secure fit between the nut and the bottom of the mounting groove. This eliminates the need for additional clips, adhesives, or covering structures, preventing conventional nuts from spinning freely due to insufficient friction during tightening. By designing the bottom of the mounting groove as a V-shaped concave structure, the hexagonal nut automatically enters the positioning angle upon insertion and achieves a reliable limiting effect under force, improving assembly efficiency and structural durability. This structure also facilitates quick nut replacement between different mounting positions 72, maintaining the maintainable and universal installation advantages of the base shell.

[0038] In this specific embodiment, multiple mounting positions 72 on the connecting column 7 are evenly spaced along the axial direction of the connecting column 7. When the connecting member 8 is replaced between different mounting positions 72, it maintains the same assembly depth and locking angle, thereby ensuring consistent stress at each position. This axially evenly distributed structure allows the connecting column 7 to provide multiple usable mounting points on the same axis. When a mounting position 72 is damaged, an adjacent mounting position 72 can be directly selected for continued assembly without replacing the entire bottom shell or re-drilling holes, improving the maintainability and service life of the structure.

[0039] Furthermore, the even distribution of mounting positions 72 along the axial direction helps to balance the overall force on the bottom shell. Whether tightening screws or fixing components, the torque on the connecting column 7 in the axial direction is evenly distributed, which can effectively prevent fracture problems caused by fatigue or stress concentration in local plastic columns. This structure also facilitates mold manufacturing and subsequent automated assembly, giving the bottom shell good versatility and standardization.

[0040] In this specific embodiment, multiple connecting posts 7 are arranged symmetrically inside the housing 6, with each connecting post 7 positioned close to the inner wall of the housing 6. This distribution makes the housing 6 more stable under overall stress. In a specific embodiment, the multiple connecting posts 7 are distributed on the left and right sides inside the housing 6, close to the inner walls of the left and right sides of the housing 6. This effectively supports the structure between the inner wall and the external mounting surface, thus preventing local deformation of the housing 6 when screws are tightened or components are fixed. When the bottom shell is used to install different types of modules (such as control panels, communication gateways, sensor components, etc.), the symmetrically arranged connecting posts 7 can provide balanced support in all directions, ensuring that each module remains flat and fitted after installation, preventing the housing 6 from warping or tilting.

[0041] Furthermore, the arrangement of the connecting pillars 7 close to the inner wall of the housing 6 improves the utilization of the space in the housing 6, keeping the central area of ​​the housing 6 open to accommodate electronic components, wiring, or other functional structures. This arrangement also facilitates mold forming and production assembly, reducing material thickness while maintaining overall strength, thus improving the lightweight and structural rigidity of the bottom shell.

[0042] In a specific embodiment of this application, two connecting posts 7 are provided, arranged close to the inner walls of the left and right sides of the housing 6, forming a symmetrical distribution structure. The two connecting posts 7 extend parallel in space, their positions close to the side walls of the housing 6, forming stable support points on both sides of the bottom housing, providing reliable fixation for components such as control panels, gateway modules, or sensor assemblies. Each connecting post 7 has multiple axially distributed mounting slots, with the opening of each slot facing the upper inner wall of the housing 6. That is, when the bottom housing is installed on a wall, the opening of the mounting slot faces upwards, opening from the upper side of the housing 6. During assembly, the connecting piece 8 (such as a nut or metal insert) is inserted from above and is not easily dislodged after assembly.

[0043] In addition, the arrangement of the slot facing the upper side of the housing 6 can also use gravity to assist in the positioning of the connector 8 during the screw tightening process, so that the connector 8 naturally rests against the bottom of the mounting slot, ensuring that the threaded hole and the hollow through hole 71 in the connecting column 7 remain coaxial.

[0044] In a specific embodiment of this application, the connecting post 7 is provided with a pin hole on the side of each mounting groove facing away from the groove opening. The pin hole is connected to the mounting groove and is used to insert a pin or other slender tool from the back of the connecting post 7 when it is necessary to disassemble or replace the connector 8, and push the connector 8 out of the mounting groove through the pin hole.

[0045] In practical applications of the base shell, when the connector 8 (such as a nut or embedded metal sleeve) becomes worn, stripped, or needs replacement due to long-term use, the old part can be easily ejected from the back of the connector 7 through the ejector pin hole, thereby improving the operability and reliability of assembly and maintenance. Specifically, by providing an ejector pin hole communicating with the mounting slot on the side of the connector 7 opposite to the slot, the connector 8 can be quickly removed and replaced without affecting normal assembly, significantly improving the maintenance convenience of the base shell.

[0046] In a specific embodiment of this application, the connecting column 7 is connected to the inner wall of the housing 6 by a reinforcing rib. The reinforcing rib is used to enhance the overall support rigidity between the connecting column 7 and the housing 6, and to prevent column displacement, inner wall deformation, etc. when the screws are tightened or under long-term load.

[0047] The reinforcing rib is preferably an arc-shaped transition structure, with its two ends connecting to the outer wall of the connecting column 7 and the inner wall of the shell 6, respectively. The arc-shaped structure can effectively disperse stress during force transmission, avoiding stress concentration at the root of the rib or the column connection, thereby improving the fatigue resistance of the structure. Compared with right-angle ribs, arc-shaped reinforcing ribs can reduce the number of stress points in the mold and reduce the risk of molding shrinkage and stress cracking.

[0048] Furthermore, the arrangement direction of the arc-shaped reinforcing ribs can be adjusted according to the distribution of the connecting columns. When the connecting columns are located close to the inner walls on both sides of the shell, the reinforcing ribs can extend radially in an arc shape, forming a stable triangular mechanical support relationship, so that the connecting columns maintain positioning accuracy under multi-directional forces.

[0049] By adopting a reinforced rib connection structure with an arc transition, the connecting column and the shell form a stable integrated force-bearing system, which not only improves the overall strength and deformation resistance of the bottom shell, but also improves the support stability during assembly, ensuring the reliability and durability of the bottom shell in long-term use.

[0050] In a specific embodiment, the bottom shell structure is an 86-type bottom box, with three axially spaced mounting positions on the connecting post, thereby extending the service life of the 86 bottom box by at least three times. The nut can be initially installed in the first mounting position. Common failure modes include aging and cracking of the plastic parts, causing the nut to lose its structural anti-rotation function. When the screw or bolt passes through the through hole and locks with the nut, the excess screw length can be carried to the next section, thus unaffected by the screw's length. When the first plastic section fails, the nut can be removed and installed in the second mounting position, repairing the 86 bottom box and allowing it to continue to be used. This process can be repeated for the third section or the connecting post on the other side, extending the lifespan of the 86 bottom box. This significantly extends the service life of the screw posts, preventing cracking caused by repeated localized stress. This novel structure effectively alleviates the aging and cracking problems of screw posts caused by repeated disassembly and assembly.

[0051] It should be understood that the terminology used herein is for the purpose of describing particular exemplary embodiments only and is not intended to be limiting. Unless the context clearly indicates otherwise, the singular forms “a,” “an,” and “described” as used herein may also include the plural forms. The terms “comprising,” “including,” “containing,” and “having” are inclusive and therefore indicate the presence of the stated features, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, elements, components, and / or combinations thereof. The method steps, processes, and operations described herein are not construed as requiring them to be performed in a particular order described or illustrated unless the order of performance is explicitly indicated. It should also be understood that additional or alternative steps may be used.

[0052] Although terms such as first, second, third, etc., may be used in this document to describe multiple elements, components, regions, layers, and / or segments, these elements, components, regions, layers, and / or segments should not be limited by these terms. These terms may be used only to distinguish one element, component, region, layer, or segment from another. Unless the context clearly indicates otherwise, terms such as "first," "second," and other numerical terms used herein do not imply order or sequence. Therefore, the first element, component, region, layer, or segment discussed below may be referred to as the second element, component, region, layer, or segment without departing from the teachings of the exemplary embodiments.

[0053] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A bottom shell structure, comprising: A housing with an opening on one side, and a connecting column disposed within the housing, characterized in that the connecting column is axially hollow and its end faces the opening side of the housing, and the side of the connecting column is provided with a plurality of mounting positions, the mounting positions being used to install connectors with threaded holes, and when the connector is installed in any mounting position, its threaded hole overlaps with or is within the through hole formed by the axially hollow connecting column.

2. The bottom shell structure according to claim 1, characterized in that, The mounting position is a mounting groove provided on the side of the connecting column. The mounting groove communicates with the hollow part of the connecting column, so that the connector installed in the mounting position is coaxial with the connecting column and is limited.

3. The bottom shell structure according to claim 2, characterized in that, The width between the two inner walls of the mounting groove parallel to the axis of the connecting column is greater than the diameter of the through hole formed in the hollow part of the connecting column, and the width of the connector is adapted to the width between the two inner walls of the mounting groove parallel to the axis of the connecting column.

4. The bottom shell structure according to claim 2, characterized in that, The through hole formed in the hollow connecting column passes through the two inner walls of the mounting groove that are perpendicular to the axis of the connecting column, and the edge of the through hole is inside the edge of the two inner walls that are perpendicular to the axis of the connecting column.

5. The bottom shell structure according to claim 2, characterized in that, The connector is a hexagonal nut, and the bottom of the mounting groove is adapted to the hexagonal nut in a V-shape.

6. The bottom shell structure according to claim 1, characterized in that, The mounting positions are evenly spaced along the axial direction of the connecting column.

7. The bottom shell structure according to claim 1, characterized in that, The connecting posts are provided in multiple forms and are symmetrically distributed within the housing and close to the inner wall of the housing.

8. The bottom shell structure according to claim 2, characterized in that, Two connecting columns are provided and are located near the inner walls of the left and right sides of the housing, and the opening of the mounting groove faces the inner wall of the upper side of the housing.

9. The bottom shell structure according to claim 8, characterized in that, The side of the connecting column facing each of the slots is provided with a pin hole that communicates with the mounting slot.

10. The bottom shell structure according to claim 1, characterized in that, The connecting column is connected to the inner wall of the shell by reinforcing ribs.

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