Double-layer curtain wall
By using a double-skin curtain wall structure composed of polycarbonate panels and glass, combined with the connection between adapter components and beams, the problems of heavy weight, high cost and complex construction of traditional double-skin curtain walls are solved, achieving the effect of lightweight, low cost and efficient installation.
Patent Information
- Application Number
- CN202422857068.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-21
- Publication Date
- 2025-09-30
- Estimated Expiration
- 2034-11-21
AI Technical Summary
Traditional double-skin curtain walls are expensive, have bulky frames, complex structures, and are inconvenient to construct. In particular, the support method for the inner and outer glass panels results in a reduction in the building's usable area or a complex frame structure.
Polycarbonate panels are used as outer panels and glass as inner panels, which are connected with crossbeams in combination with adapter components to simplify the skeleton structure, and the installation of the outer panels is achieved through the detachable fixation of connectors and adapters.
It reduces the weight and cost of the curtain wall, improves thermal insulation performance, simplifies the construction process, and enhances installation efficiency and stability.
Smart Images

Figure CN223398267U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the technical field of curtain walls, and in particular relates to a double-layer curtain wall. Background Art
[0002] Double-skin curtain walls offer excellent thermal insulation, utilizing the chimney effect to create an independent airflow exchange space between the inner and outer curtain walls, creating a heat shield. This design prevents indoor heat from flowing outdoors in winter and prevents outdoor heat from flowing indoors in summer, maintaining a relatively constant thermal environment indoors. Traditional double-skin curtain walls utilize two layers of glass panels, which have drawbacks such as high curtain wall costs, bulky frames, space occupation, and complex structures. For example, when the inner and outer double-layer glass panels are supported by independent frames, the curtain wall frame becomes too bulky and reduces the building's usable area. When the inner and outer double-layer glass panels are supported by a single independent frame, the frame structure becomes too complex and inconvenient to construct. Utility Model Content
[0003] In order to overcome the above-mentioned shortcomings of the prior art, the purpose of the present invention is to provide a double-layer curtain wall, which can effectively reduce the construction cost, has a simple and reliable structure, and is easy to construct.
[0004] The technical solution adopted by the utility model to solve its technical problems is:
[0005] A double-layer curtain wall comprises columns, beams, a plurality of inner glass layers, a plurality of outer panels, and a transition assembly for assembling the outer panels; the outer panels are polycarbonate panels; the columns and beams are arranged in a crisscross pattern;
[0006] The inner glass is installed between two upper and lower adjacent beams and is connected and installed through the bottom and top of the two upper and lower adjacent beams;
[0007] The outer plate is connected and installed to the outer side of the beam through the adapter assembly.
[0008] In a preferred embodiment of the present invention, the adapter assembly includes a connector and an adapter; the connector and the adapter are detachably and fixedly connected; wherein,
[0009] The connecting piece is locked and fixed on the outer side of the beam;
[0010] The adapter is connected to the inner side of the outer plate.
[0011] Preferably, the connecting member includes a first connecting portion and a second connecting portion; the first connecting portion and the second connecting portion are perpendicular to each other; the first connecting portion is locked and fixed to the outer side of the beam, one end of the second connecting portion is connected to the first connecting portion, and the other end of the second connecting portion extends outward;
[0012] The second connecting portion is used for detachably fixed connection with the adapter.
[0013] Preferably, the adapter comprises a splicing portion and an assembling portion; the splicing portion and the assembling portion are perpendicular to each other; the splicing portion is used to connect with the second connecting portion; the assembling portion is used to connect with the outer plate;
[0014] Among them, the second connecting part is provided with a plurality of first connecting holes, and the splicing part is provided with a plurality of second connecting holes; in the assembled state, each of the first connecting holes and each of the second connecting holes are adapted and locked and fixed by bolts and nuts.
[0015] Preferably, the second connecting hole is in an oblong shape.
[0016] Preferably, a serration structure is provided on the side of the splicing portion facing the nut.
[0017] Preferably, the assembly part includes a first limiting plate and a second limiting plate, the second limiting plate is located on the outside of the first limiting plate, and the first limiting plate is wider than the second limiting plate; the first limiting plate and the second limiting plate are both connected to the splicing part and extend to both sides, and two limiting grooves are formed between the first limiting plate and the second limiting plate, and the two limiting grooves are respectively facing both sides; the side edges of the outer layer plate are limited in the limiting grooves.
[0018] Preferably, one of the limiting notches on the same adapter is an assembly notch, and a guide groove is provided on a portion of the first limiting plate corresponding to the assembly notch; the guide groove includes a first transverse groove, a second transverse groove, a first vertical groove, and a second vertical groove that are interconnected; along the side edge of the first limiting plate in a direction to the assembly notch, the first transverse groove, the first vertical groove, the second transverse groove, and the second vertical groove are arranged in sequence, and the second transverse groove is lower than the first transverse groove, the first vertical groove connects the first transverse groove and the second transverse groove, and the middle portion of the second vertical groove is connected to the second transverse groove;
[0019] The side of the outer layer plate is provided with a plate clamp, and the plate clamp is provided with a clamping groove; both side edges of the outer layer plate are provided with a protrusion adapted to the clamping groove, and the protrusion on one side is inserted into the clamping groove to achieve the fixation of the plate clamp and the outer layer plate; the inner side of the plate clamp is provided with a hook, and the hook can be inserted into the guide groove and move in the guide groove.
[0020] Preferably, the widths of the first transverse groove, the first vertical groove, the second transverse groove and the second vertical groove are D1, D2, D3 and D4 respectively, and the height of the second vertical groove is D5;
[0021] The height of the hanging portion of the hook is D6, the total height of the hook portion of the hook is D7, and the thickness of the hook is D8;
[0022] Among them, D1>D7, D2>D8, D3>D6 and D3<D7, D4>D8, D5>D6.
[0023] Preferably, both sides of the outer layer panels are further provided with slot structures, and the slot structures on both sides of the outer layer panels are staggered with each other; in the assembled state, two adjacent outer layer panels are embedded in each other through their respective slot structures.
[0024] Compared with the prior art, the beneficial effects of the present invention are:
[0025] The double-layer curtain wall of this utility model innovatively combines polycarbonate and glass to form a new double-layer curtain wall structure, using polycarbonate panels as the outer panels and inner glass made of glass as the inner layer, making the curtain wall structure lighter, lower in cost, and having better thermal insulation and sound insulation performance.
[0026] At the same time, in order to better realize the assembly of the outer panels, the curtain wall beams are used in combination with the use of adapter components to facilitate the installation of the outer panels, effectively simplify the skeleton structure of the curtain wall, and make construction more convenient. BRIEF DESCRIPTION OF THE DRAWINGS
[0027] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.
[0028] Figure 1 It is a side view of the double-layer curtain wall of the present invention.
[0029] Figure 2 This is a top view of the double-layer curtain wall of the present invention.
[0030] Figure 3 for Figure 2 Schematic top view of two adjacent outer panels, panel clamps and adapters.
[0031] Figure 4 This is a three-dimensional exploded view of the adapter.
[0032] Figure 5 This is a schematic diagram of the back side of the adapter.
[0033] Figure 6 A side view of the plate clamp.
[0034] Figure 7A top view of the plate clamp.
[0035] Figure 8 This is a three-dimensional schematic diagram of the plate clamp and adapter.
[0036] in:
[0037] 1- pillar;
[0038] 2- crossbeam;
[0039] 3-Inner glass;
[0040] 4-outer plate, 401-slot structure, 402-convex part;
[0041] 5-Adapter assembly, 501-Connector, 5011-First connecting part, 5012-Second connecting part, 50121-First connecting hole, 50212-Second connecting hole, 502-Adapter, 5021-Splicing part, 50211-Sawtooth structure, 5022-First limiting plate, 50221-Left limiting plate, 50222-Right limiting plate, 5023-Second limiting plate, 5024-Assembly notch, 5025-Conventional limiting notch;
[0042] 6-Bottom support;
[0043] 7-plate clamp, 701-clamping slot, 702-hook;
[0044] 8-bolts;
[0045] 9-nut;
[0046] 10-gasket;
[0047] 11- first transverse groove;
[0048] 12-first vertical slot;
[0049] 13- second transverse groove;
[0050] 14-Second vertical slot. DETAILED DESCRIPTION
[0051] In order to more clearly understand the above-mentioned purposes, features and advantages of the present invention, the present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that, in the absence of conflict, the embodiments of this application and the features in the embodiments can be combined with each other. In the following description, many specific details are set forth in order to fully understand the present invention. The embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.
[0052] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art in the art of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention.
[0053] Example 1
[0054] See also Figures 1-8 , this embodiment discloses a double-layer curtain wall, including columns 1, beams 2, a plurality of inner glass layers 3, a plurality of outer panels 4 and an adapter assembly 5 for assembling the outer panels 4. The columns 1 and beams 2 are arranged in a crisscross pattern, and the beams 2 are arranged on the outside of the columns 1. The inner glass layer 3 is installed between two upper and lower adjacent beams 2, and is connected and installed through the bottom and top of the two upper and lower adjacent beams 2. The installation and structure of the beams 2, columns 1 and inner glass layer 3 of this embodiment can be referred to the prior art, and will not be described in detail here. The technical means that can realize this solution in the prior art shall prevail. For example, the installation of the inner glass layer 3 and the beam 2 can be achieved by slotting the top and bottom of the beam 2, and combining the use of card slot accessories to complete the installation and fixation of the inner glass layer 3.
[0055] The outer panel 4 of this embodiment is connected and installed to the outer side of the crossbeam 2 via an adapter assembly 5. At the same time, the outer panel 4 of this embodiment is made of polycarbonate board, forming a new double-layer curtain wall system consisting of a polycarbonate panel curtain wall on the outer layer and a glass panel curtain wall on the inner layer. This utility model creates a double-layer curtain wall at a lower material cost, achieving thermal insulation performance that is superior to traditional double-layer curtain walls. Its deadweight is lighter than that of traditional double-layer curtain walls, and its structure is simpler, making the installation process more convenient, effectively improving the efficiency of on-site installation of the double-layer curtain wall, and reducing the difficulty of on-site construction. In addition, the polycarbonate panel of this embodiment is preferably a hollow board, which is conducive to further improving its thermal insulation performance.
[0056] Furthermore, the adapter assembly 5 of this embodiment includes a connector 501 and an adapter 502; the connector 501 and the adapter 502 are detachably fixedly connected. The connector 501 is locked and fixed to the outside of the beam 2; and the adapter 502 is connected to the inside of the outer plate 4.
[0057] The connector 501 includes a first connector portion 5011 and a second connector portion 5012; the first connector portion 5011 and the second connector portion 5012 are perpendicular to each other. The first connector portion 5011 is locked and fixed to the outer side of the crossbeam 2. One end of the second connector portion 5012 is connected to the first connector portion 5011, and the other end of the second connector portion 5012 extends outward. The second connector portion 5012 is configured for removable connection to the adapter 502. In this embodiment, the first connector portion 5011 is locked and fixed to the outer side of the crossbeam 2 using screws, bolts 8, and nuts 9. For example, in this embodiment, screws are used for locking, with screws on both sides of the second connector portion 5012 locking and fixing the crossbeam 2.
[0058] The adapter 502 includes a splicing portion 5021 and an assembly portion. The splicing portion 5021 and the assembly portion are perpendicular to each other. The splicing portion 5021 is used to connect to the second connecting portion 5012, while the assembly portion is used to connect to the outer panel 4. The second connecting portion 5012 is provided with a plurality of first connecting holes 50121, and the splicing portion 5021 is provided with a plurality of second connecting holes 50212. In the assembled state, each first connecting hole 50121 is adapted to fit with each second connecting hole 50212, and is secured by bolts 8 and nuts 9.
[0059] The second connecting hole 50212 of this embodiment is oblong. Both the first connecting hole 50121 and the second connecting hole 50212 are provided. A gasket 10 is also provided when the nut 9 and bolt 8 are engaged, which helps improve the locking and fixing effect and reduce noise. A serrated structure 50211 is provided on the side of the joint 5021 facing the nut 9. This further improves the locking stability between the joint 5021, the gasket 10, and the nut 9. The gasket 10 of this embodiment is a toothed gasket. When adjusting the position of the adapter 502 along the oblong second connecting hole 50212, the serrated structure 50211 and the teeth of the toothed gasket enable more precise fine-tuning of the position.
[0060] Furthermore, to facilitate the connection and fixation between the outer panel 4 and the adapter 502, this embodiment optimizes the design of the assembly portion of the adapter 502. Specifically, the assembly portion includes a first limiting plate 5022 and a second limiting plate 5023. The second limiting plate 5023 is located outside the first limiting plate 5022 and is wider than the second limiting plate 5023. The first limiting plate 5022 and the second limiting plate 5023 are both connected to the splicing portion 5021 and extend to both sides. Two limiting notches are formed between the first limiting plate 5022 and the second limiting plate 5023, and the two limiting notches face toward both sides. The side edges of the outer panel 4 are retained in the limiting notches.
[0061] Among them, one of the limiting notches on the same adapter 502 is an assembly notch 5024, and the other limiting notch is a conventional limiting notch 5025. Specifically, the first limiting plate 5022 of this embodiment is divided into a left limiting plate 50221 and a right limiting plate 50222. The limiting notch between the left limiting plate 50221 and the second limiting plate 5023 is a conventional limiting notch 5025, and the limiting notch between the right limiting plate 50222 and the second limiting plate 5023 is an assembly notch 5024.
[0062] Meanwhile, a guide groove is provided on the right limit plate 50222. A plate clamp 7 is provided on the side of the outer plate 4, and a clamping groove 701 is provided on the plate clamp 7. Both sides of the outer plate 4 are provided with a protrusion 402 adapted to the clamping groove 701. The protrusion 402 on one side is inserted into the clamping groove 701 to secure the plate clamp 7 to the outer plate 4. A hook 702 is provided on the inner side of the plate clamp 7, which can be inserted into and moved in the guide groove.
[0063] Furthermore, in this embodiment, the right stop plate 50222 corresponding to the assembly notch 5024 has a larger area, which can serve as a guide during the installation of the outer panel 4. The guide groove includes a first transverse groove 11, a second transverse groove 13, a first vertical groove 12, and a second vertical groove 14, which are interconnected. Along the side edge of the right stop plate 50222 in the direction toward the assembly notch 5024, the first transverse groove 11, the first vertical groove 12, the second transverse groove 13, and the second vertical groove 14 are arranged in sequence, with the second transverse groove 13 being lower than the first transverse groove 11. The first vertical groove 12 connects the first transverse groove 11 and the second transverse groove 13, and the middle portion of the second vertical groove 14 is connected to the second transverse groove 13.
[0064] Furthermore, the widths of the first transverse groove 11, first vertical groove 12, second transverse groove 13, and second vertical groove 14 of this embodiment are defined as D1, D2, D3, and D4, respectively, and the height of the second vertical groove 14 is defined as D5. The height of the hanging portion of the hook 702 of this embodiment is defined as D6, the total height of the hook portion of the hook 702 is defined as D7, and the thickness of the hook 702 is defined as D8. Among them, D1>D7, D2>D8, D3>D6, and D3<D7, D4>D8; in this embodiment, D4>D8 is set to relieve the lateral strain of the outer curtain wall; while D5>D6, D5 can be preferably set to a larger size to allow a certain degree of relative movement between the panel clamp 7 and the transfer code to relieve thermal deformation caused by heating of the outer curtain wall.
[0065] In this embodiment, there are two guide grooves on each adapter 502 and they are arranged up and down, and there are also two corresponding hooks 702 on the plate clamp 7, which is beneficial to improving the limitation of the outer layer plate 4 and the reliability and stability after assembly.
[0066] The bottom of the outer panel 4 is fixed and limited by the bottom support 6 of the curtain wall, and the bottom support 6 can be fixedly connected to the crossbeam 2. The bottom support 6 is provided with a fixing groove, a limiting groove or other limiting structure that can limit and fix the bottom of the outer panel 4, so that during installation, the bottom of the outer panel 4 can be inserted into the limiting structure on the bottom support 6. Combined with the connection between the adapter assembly 5 and the crossbeam 2, the outer panel 4 can be effectively fixed.
[0067] In this embodiment, both sides of the outer layer plate 4 are further provided with a slot structure 401, and the slot structures 401 on both sides of the outer layer plate 4 are staggered with each other; in the assembled state, the adjacent outer layer plates 4 are embedded with each other through the concave and convex parts 402 of their respective slot structures 401 to avoid loosening and dislocation, so as to achieve a reliable assembly and adaptation effect.
[0068] When installing the outer panel 4, first insert one of the protrusions 402 on the side of the outer panel 4 into the clamping groove 701 of the panel clamp 7, so that the panel clamp 7 and the outer panel 4 form a single unit. The clamping groove 701 and the protrusion 402 can be fixed by an interference fit. Then, the hook 702 on the panel clamp 7 is inserted into the corresponding guide groove and moves along the first transverse groove 11, the first vertical groove 12, the second transverse groove 13, and the second vertical groove 14 in sequence. Finally, the hook 702 is relatively restrained in the second vertical groove 14, and the side of the outer panel 4 is inserted into the assembly notch 5024.
[0069] Specifically, the installation of the outer panel 4 includes the following stages: In the first stage, the right limit plate 50222 at the assembly notch 5024 is used for rapid positioning. The outer panel 4 is leaned against this position, and the hook 702 of the panel clamp 7 is inserted into the first transverse groove 11. After the panel clamp 7 naturally falls due to gravity, it can be hung on the adapter 502. In this case, since D1>D7, the hook 702 of the panel clamp 7 can penetrate into the first transverse groove 11 of the adapter 502. In the second stage, the hook 702 of the panel clamp 7 moves laterally in the first transverse groove 11, and drives the outer panel 4 to move laterally until it reaches the first vertical groove 12. At this point, the slot structure 401 on the side of the outer panel 4 can be initially buckled into the socket of the slot structure 401 of the previously installed outer panel 4. In the third stage, the hook 702 of the panel clamp 7 can move vertically downward in the first vertical slot 12 and fall into the second horizontal slot 13. This prevents the two outer panels 4 that have been aligned and plugged in from becoming loose or misaligned again. The fact that D2>D8 ensures that the hook 702 falls smoothly, avoiding the effects of unevenness or installation errors on the outer panels 4. In the fourth stage, the hook 702 of the panel clamp 7 can move horizontally in the second horizontal slot 13, driving the outer panel 4 to move horizontally until it reaches the second vertical slot 14. At this point, the slot structure 401 of the outer panel 4 can be fully plugged into the slot structure 401 of the previously installed outer panel 4. The fact that D3>D6 and D3<D7 prevent the hook 702 from falling out of the second horizontal slot 13 during this horizontal movement, causing misalignment. In the fifth stage, the outer panel 4 is now installed. The retaining structure 401 between the two outer panels prevents the newly installed outer panel 4 from falling out. The larger dimension D5 in the second vertical slot 14 allows for a certain amount of relative movement between the panel clamp 7 and the adapter 502 to relieve thermal deformation caused by heating of the outer curtain wall. The difference between D4 and D8 also reduces lateral strain in the outer curtain wall. Finally, the adapter 502 on the other side of the outer panel 4 is installed, completing the installation and securing of the outer panel 4.
[0070] In actual construction, the side edges of the outer panels 4 can be installed with panel clips 7 at regular intervals, and correspondingly, the adapter components 5 can be installed at regular intervals of height on the crossbeams 2 or on each crossbeam 2. In this way, when installing the outer panels 4, the cooperation between the multiple panel clips 7 and the adapter components 5 can achieve rapid positioning and hanging, and have good installation stability and reliability.
[0071] The outer panel 4 of this embodiment is horizontally constrained by the adapter 502 and vertically constrained by the curtain wall bottom support 6. The outer panel 4 and the adapter 502 can move freely relative to each other in the vertical direction, releasing the thermal deformation of the outer curtain wall.
[0072] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Therefore, any modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.
Claims
1. A double-layer curtain wall, characterized in that: It includes columns, beams, a plurality of inner glass layers, a plurality of outer panels, and a transition assembly for assembling the outer panels; the outer panels are polycarbonate panels; the columns and beams are arranged in a crisscross pattern; The inner glass is installed between two upper and lower adjacent beams and is connected and installed through the bottom and top of the two upper and lower adjacent beams; The outer plate is connected and installed to the outer side of the beam through the adapter assembly.
2. The double-skin curtain wall according to claim 1, characterized in that: The adapter assembly includes a connecting piece and an adapter; the connecting piece and the adapter are detachably fixedly connected; wherein, The connecting piece is locked and fixed on the outer side of the beam; The adapter is connected to the inner side of the outer plate.
3. The double-skin curtain wall according to claim 2, characterized in that: The connecting member includes a first connecting portion and a second connecting portion; the first connecting portion and the second connecting portion are perpendicular to each other; the first connecting portion is locked and fixed to the outer side of the beam, one end of the second connecting portion is connected to the first connecting portion, and the other end of the second connecting portion extends outward; The second connecting portion is used for detachably fixed connection with the adapter.
4. The double-skin curtain wall according to claim 3, characterized in that: The adapter includes a splicing portion and an assembling portion; the splicing portion and the assembling portion are perpendicular to each other; the splicing portion is used to connect with the second connecting portion; the assembling portion is used to connect with the outer plate; Among them, the second connecting part is provided with a plurality of first connecting holes, and the splicing part is provided with a plurality of second connecting holes; in the assembled state, each of the first connecting holes and each of the second connecting holes are adapted and locked and fixed by bolts and nuts.
5. The double-skin curtain wall according to claim 4, characterized in that: The second connecting hole is in an oblong shape.
6. The double-skin curtain wall according to claim 4, characterized in that: A serration structure is provided on one side of the splicing portion facing the nut.
7. The double-skin curtain wall according to claim 4, characterized in that: The assembly part includes a first limiting plate and a second limiting plate, the second limiting plate is located on the outside of the first limiting plate, and the first limiting plate is wider than the second limiting plate; the first limiting plate and the second limiting plate are both connected to the splicing part and extend to both sides, and two limiting grooves are formed between the first limiting plate and the second limiting plate, and the two limiting grooves are respectively facing both sides; the side edges of the outer layer plate are limited in the limiting grooves.
8. The double-skin curtain wall according to claim 7, characterized in that: One of the limiting notches on the same adapter is an assembly notch, and a guide groove is provided on a portion of the first limiting plate corresponding to the assembly notch; the guide groove includes a first transverse groove, a second transverse groove, a first vertical groove, and a second vertical groove that are interconnected; along the side edge of the first limiting plate in a direction to the assembly notch, the first transverse groove, the first vertical groove, the second transverse groove, and the second vertical groove are arranged in sequence, and the second transverse groove is lower than the first transverse groove, the first vertical groove connects the first transverse groove and the second transverse groove, and the middle portion of the second vertical groove is connected to the second transverse groove; The side of the outer layer plate is provided with a plate clamp, and the plate clamp is provided with a clamping groove; both side edges of the outer layer plate are provided with a protrusion adapted to the clamping groove, and the protrusion on one side is inserted into the clamping groove to achieve the fixation of the plate clamp and the outer layer plate; the inner side of the plate clamp is provided with a hook, and the hook can be inserted into the guide groove and move in the guide groove.
9. The double-skin curtain wall according to claim 8, characterized in that: The widths of the first transverse groove, the first vertical groove, the second transverse groove, and the second vertical groove are D1, D2, D3, and D4 respectively, and the height of the second vertical groove is D5; The height of the hanging portion of the hook is D6, the total height of the hook portion of the hook is D7, and the thickness of the hook is D8; Among them, D1>D7, D2>D8, D3>D6 and D3<D7, D4>D8, D5>D6.
10. The double-skin curtain wall according to claim 1, characterized in that: Both sides of the outer layer plate are further provided with a slot structure, and the slot structures on both sides of the outer layer plate are staggered with each other; in the assembled state, two adjacent outer layer plates are embedded in each other through their respective slot structures.