Packaging structure of air conditioner indoor unit

Abstract

The embodiment of the invention provides a packaging structure of an air conditioner indoor unit, and relates to the technical field of air conditioner packaging. The packaging structure of the air conditioner indoor unit comprises a packaging box and a buffering box. The packaging box comprises a first box body and a second box body which are hinged to each other. The buffer box comprises a first buffer box body and a second buffer box body, the first buffer box body is fixedly connected to an inner cavity of the first box body, the second buffer box body is fixedly connected to an inner cavity of the second box body, and when the first box body and the second box body are covered, the first buffer box body and the second buffer box body are opposite and form a containing cavity for containing the air conditioner indoor unit. Therefore, when the indoor unit of the air conditioner is packaged, an operator only needs to place the indoor unit of the air conditioner in the first buffer box or the second buffer box and then enables the second box body to rotate relative to the first box body, so that the indoor unit of the air conditioner is contained in the containing cavity after the first box body and the second box body are covered, and the packaging process of the indoor unit is simplified.

Description

Technical Field

[0001] The present invention relates to the technical field of air conditioner packaging, and in particular to a packaging structure of an air conditioner indoor unit. Background Art

[0002] As an important part of the air conditioner, the quality of the indoor unit can directly affect the user's overall judgment of the air conditioner. In order to ensure that the indoor unit of the air conditioner does not suffer quality wear during transportation, the packaging structure plays a key role.

[0003] The inventor has found that the packaging structures of some existing indoor units are divided into a packaging box and a buffer foam. During the packaging process, the operator needs to put the indoor unit into the buffer foam and then put it into the packaging box, which makes the packaging process more complicated. Summary of the invention

[0004] An object of the present invention is to provide a packaging structure for an indoor unit of an air conditioner, which can simplify the packaging process of the indoor unit.

[0005] The embodiment of the present invention is achieved as follows:

[0006] In a first aspect, the present invention provides a packaging structure of an air conditioner indoor unit, comprising:

[0007] A packing box, comprising a first box body and a second box body which are hinged to each other;

[0008] The buffer box includes a first buffer box and a second buffer box. The first buffer box is fixedly connected to the inner cavity of the first box body, and the second buffer box is fixedly connected to the inner cavity of the second box body. When the first box body and the second box body are covered, the first buffer box and the second buffer box are opposite to each other and form a accommodating cavity for accommodating the indoor unit of the air conditioner.

[0009] Through the above arrangement, the operator only needs to place the air-conditioning indoor unit in the first buffer box or the second buffer box, and then rotate the second box body relative to the first box body so that the first box body and the second box body are covered and the air-conditioning indoor unit is placed in the accommodating cavity, thereby simplifying the packaging process of the indoor unit.

[0010] In an optional embodiment, the dimension of the side wall of the first box body in the depth direction of its own inner cavity is smaller than the length dimension of the outer side wall of the first buffer box in the first direction, and the first direction is parallel to the depth direction of the inner cavity of the first box body.

[0011] The above arrangement facilitates the second box to be snapped and assembled on the first box, facilitates the installation and positioning of the second box, and enables the accommodating cavity formed by the first buffer box and the second buffer box to be completely covered to prevent external dust from entering the accommodating cavity.

[0012] In an optional embodiment, the difference between the dimension of the side wall of the first box body in the depth direction of its inner cavity and the length dimension of the outer side wall of the first buffer box in the first direction is in the range of 10 to 20 cm.

[0013] Through the above arrangement, within a suitable range, it can be ensured that the second box body is conveniently snapped and assembled with the first box body during the process of covering the second box body with the first box body.

[0014] In an optional embodiment, an inner cavity of at least one of the first buffer tank and the second buffer tank is provided with an anti-wear layer.

[0015] Through the above arrangement, the anti-wear layer can prevent the outer surface of the air-conditioning indoor unit from being scratched due to friction between the inner wall of the accommodating cavity and the air-conditioning indoor unit.

[0016] In an optional embodiment, the anti-wear layer is made of pearl cotton.

[0017] Through the above arrangement, the accommodating cavity can be made to have the pearl cotton with good softness and cushioning properties, and also has the properties of waterproof and moisture-proof, shockproof, sound-proof, heat-insulating, tough and recyclable.

[0018] In an optional embodiment, the thickness of the anti-wear layer is in the range of 0.5 to 1 mm.

[0019] Through the above arrangement, the amount of the anti-wear layer can be reduced while ensuring that the outer surface of the air conditioner indoor unit is not scratched.

[0020] In an optional embodiment, a side wall of the first buffer box is provided with an avoidance groove for avoiding the second buffer box, the avoidance groove is close to the hinge between the first box body and the second box body, and the depth direction of the avoidance groove is parallel to the depth direction of the inner cavity of the first box body.

[0021] Through the above arrangement, interference between the first buffer box and the second buffer box can be avoided during the rotation of the first box body relative to the second box body.

[0022] In an optional embodiment, the depth of the avoidance groove is in the range of 10 to 15 mm.

[0023] In an optional embodiment, at least one of the first buffer box and the second buffer box is provided with a material stealing hole.

[0024] Through the above arrangement, the material on the first buffer box or the second buffer box can be saved, thereby achieving the effect of saving raw material costs.

[0025] In an optional embodiment, the first buffer box includes a first end wall and a plurality of first side walls connected to the first end wall and connected end to end, and the second buffer box includes a second end wall and a plurality of second side walls connected to the second end wall and connected end to end;

[0026] The thickness of the first side wall is the same as the thickness of the first end wall, and / or the thickness of the second side wall is the same as the thickness of the second end wall.

[0027] Through the above arrangement, the side walls of the accommodating cavity can have relatively uniform anti-seismic capabilities.

[0028] The beneficial effect of the embodiment of the present invention is that the packaging structure of an air-conditioning indoor unit provided by the embodiment of the present invention includes a packaging box and a buffer box. The packaging box includes a first box body and a second box body that are hinged to each other. The buffer box includes a first buffer box and a second buffer box, the first buffer box is fixedly connected to the inner cavity of the first box body, and the second buffer box is fixedly connected to the inner cavity of the second box body. When the first box body and the second box body are covered, the first buffer box and the second buffer box are opposite to each other and form a receiving cavity for receiving the air-conditioning indoor unit. Since the first buffer box and the second buffer box are respectively fixedly connected to the inner cavities of the first box body and the second box body, when packaging the air-conditioning indoor unit, the operator only needs to place the air-conditioning indoor unit in the first buffer box or the second buffer box, and then rotate the second box body relative to the first box body, so that after the first box body and the second box body are covered, the air-conditioning indoor unit can be accommodated in the receiving cavity, thereby simplifying the packaging process of the indoor unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0030] Figure 1 A schematic diagram of the structure of the packaging structure of the air conditioner indoor unit provided by an embodiment of the present invention when it is closed;

[0031] Figure 2 An assembly schematic diagram of an indoor unit of an air conditioner when the packaging structure is opened and the indoor unit is installed at a first viewing angle is provided for an embodiment of the present invention;

[0032] Figure 3 A schematic structural diagram of an air-conditioning indoor unit packaged in a first viewing angle when opened according to an embodiment of the present invention;

[0033] Figure 4 It is a structural schematic diagram of the packaging structure of the air conditioner indoor unit provided by an embodiment of the present invention when it is opened at a second viewing angle.

[0034] Icons: 1- packaging structure of air conditioner indoor unit; 10- packaging box; 11- first box body; 12- second box body; 21- first buffer box; 211- avoidance groove; 22- second buffer box; 23- material stealing hole; 30- anti-wear layer; 2- indoor unit. DETAILED DESCRIPTION

[0035] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0036] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0037] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0038] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inside", "outside", etc. indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, or the positions or positional relationships in which the product of the invention is usually placed when in use. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific position, be constructed and operated in a specific position, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", "third", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0039] In addition, the terms "horizontal", "vertical" and the like do not mean that the components are required to be absolutely horizontal or suspended, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0040] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0041] The specific structure of the packaging structure of an air-conditioning indoor unit provided by an embodiment of the present invention and the corresponding technical effects it brings are described in detail below in conjunction with the patent drawings.

[0042] Please refer to Figure 1-Figure 4 A packaging structure 1 of an air conditioner indoor unit provided by an embodiment of the present invention includes a packaging box 10 and a buffer box.

[0043] The packaging box 10 includes a first box body 11 and a second box body 12 which are hinged to each other. That is, the first box body 11 can rotate relative to the second box body 12 to realize the opening and closing of the packaging box 10 .

[0044] by Figure 2 For reference, one end of a side wall of the first box body 11 is hinged to one end of a side wall of the second box body 12 , so that the first box body 11 can be closed or opened relative to the second box body 12 .

[0045] The buffer box includes a first buffer box 21 and a second buffer box 22. The first buffer box 21 is fixedly connected to the inner cavity of the first box body 11, and the second buffer box 22 is fixedly connected to the inner cavity of the second box body 12. When the first box body 11 and the second box body 12 are covered, the first buffer box 21 and the second buffer box 22 are opposite to each other and form a accommodating cavity for accommodating the air-conditioning indoor unit 2.

[0046] It can be understood that since the first buffer box 21 and the second buffer box 22 are fixed to the inner cavities of the first box body 11 and the second box body 12 respectively, when packing the air conditioner indoor unit 2, the operator only needs to place the air conditioner indoor unit 2 in the first buffer box 21 or the second buffer box 22, and then rotate the second box body 12 relative to the first box body 11, so that the first box body 11 and the second box body 12 are covered, so that the air conditioner indoor unit is accommodated in the accommodating cavity, without having to put the indoor unit 2 into the buffer foam first and then put it into the packaging box 10, which simplifies the packaging process of the indoor unit 2.

[0047] It should be noted that the first buffer box 21 and the second buffer box 22 can be bonded to the first box body 11 and the second box body 12 respectively. Specifically, they can be an integrated structure in which the first buffer box 21 and the second buffer box 22 are connected to the first box body 11 and the second box body 12 respectively by hot melt adhesive.

[0048] Of course, in some optional embodiments, the first buffer box 21 and the second buffer box 22 may also be bonded to the first box body 11 and the second box body 12 respectively by other types of adhesives.

[0049] It should be noted that the above-mentioned first buffer box 21 and the second buffer box 22 can be a buffer structure made of foam. Of course, to ensure that after the air-conditioning indoor unit 2 is packaged in the accommodating cavity and receives external force, the first buffer box 21 and the second buffer box 22 can absorb a certain amount of external force, thereby avoiding damage to the air-conditioning indoor unit 2 accommodated in the accommodating cavity.

[0050] Of course, in some other embodiments, the first buffer box 21 and the second buffer box 22 may also be made of other buffer materials. For example, the first buffer box 21 and the second buffer box 22 may also be made of foam material.

[0051] Optionally, the dimension of the side wall of the first box body 11 in the depth direction of its own inner cavity is smaller than the length dimension of the outer wall of the first buffer box 21 in the first direction, and the first direction is parallel to the depth direction of the inner cavity of the first box body 11 .

[0052] by Figure 2 For reference, the first box 11 is the lower box, and the second box 12 is the upper box. At this time, the height dimension of the side wall of the first box 11 close to the second box 12 is smaller than the height dimension of the first buffer box 21 close to the second buffer box 22.

[0053] It can be understood that since the second box body 12 is hinged to the first box body 11, during the rotation of the second box body 12 relative to the first box body 11, since the dimension of the side wall of the first box body 11 in the depth direction of its own inner cavity is smaller than the length dimension of the outer wall of the first buffer box 21 in the first direction, it is convenient for the second box body 12 to be snapped together on the first box body 11, and it is also convenient for the second box body 12 to be installed and positioned.

[0054] In order to facilitate the second box body 12 to be covered on the first box body 11, the dimension of the side wall of the second box body 12 in the depth direction of its own inner cavity is greater than the length dimension of the outer wall of the second buffer box 22 in the second direction, and the second direction is parallel to the depth direction of the inner cavity of the second box body 12.

[0055] Therefore, after the first box body 11 and the second box body 12 are covered, the accommodating cavity formed by the first buffer box 21 and the second buffer box 22 is completely covered. Therefore, the above arrangement can prevent external dust from entering the accommodating cavity.

[0056] The difference between the dimension of the side wall of the first box body 11 in the depth direction of its inner cavity and the length dimension of the outer side wall of the first buffer box 21 in the first direction is in the range of 10 to 20 cm.

[0057] It can be understood that the difference between the dimension of the side wall of the first box body 11 in the direction of its own inner cavity depth and the length dimension of the outer wall of the first buffer box 21 in the first direction should not be too large or too small. Within a suitable range, it can ensure that the second box body 12 is easy to snap-fit ​​and assemble with the first box body 11 during the process of covering the second box body 12 with the first box body 11.

[0058] Optionally, an anti-wear layer 30 is provided in the inner cavity of at least one of the first buffer box 21 and the second buffer box 22 .

[0059] Specifically, in the present embodiment, the inner cavities of the first buffer box 21 and the second buffer box 22 are both provided with an anti-wear layer 30. It should be noted that since the air-conditioning indoor unit 2 is accommodated in the accommodating cavity, it is inevitable that shaking will occur during transportation, causing the air-conditioning indoor unit 2 to move relative to the accommodating cavity, thereby causing the outer surface of the air-conditioning indoor unit 2 to rub against the inner cavities of the first buffer box 21 and the second buffer box 22. Since the inner side walls of the first buffer box 21 and the second buffer box 22 in the present embodiment are both provided with an anti-wear layer 30, the anti-wear layer 30 has a small friction coefficient. Therefore, the anti-wear layer 30 can prevent the outer surface of the air-conditioning indoor unit 2 from being scratched when the inner wall of the accommodating cavity rubs against the air-conditioning indoor unit 2.

[0060] Optionally, in this embodiment, the anti-wear layer 30 is made of pearl cotton. Pearl cotton has good softness and cushioning properties, and also has water-proof and moisture-proof, shock-proof, sound-proof, heat-insulating, toughness and recyclable properties.

[0061] Optionally, the thickness of the anti-wear layer 30 in this embodiment can also be in the range of 0.5 to 1 mm, which can reduce the amount of anti-wear layer while ensuring that the outer surface of the air-conditioning indoor unit 2 is not scratched. In other words, the anti-wear layer 30 can also be a pearl cotton film with a thickness in the range of 0.5 to 1 mm.

[0062] Of course, in some other embodiments, the thickness of the anti-wear layer 30 may also be outside the range of 0.5-1 mm.

[0063] In some other embodiments, the anti-wear layer 30 may also be made of other materials with low friction coefficient and good softness, such as plastic film.

[0064] It is understandable that in some existing packaging processes, in order to prevent the cushioning foam from scratching the surface of the air-conditioning indoor unit 2, the operators will pre-pack the air-conditioning indoor unit 2 into a plastic bag, then put the plastic bag containing the air-conditioning indoor unit 2 into the cushioning foam, and then put it into the packaging box 10, which makes the packaging process more cumbersome.

[0065] In this embodiment, since the inner cavities of the first buffer box 21 and the second buffer box 22 are both provided with an anti-wear layer 30, it is only necessary to place the air-conditioning indoor unit 2 in the first buffer box 21 or the second buffer box 22, and then rotate the second box body 12 relative to the first box body 11, so that the first box body 11 and the second box body 12 are covered, and the air-conditioning indoor unit is placed in the accommodating cavity, thereby simplifying the packaging process of the air-conditioning indoor unit 2.

[0066] Optionally, in the present embodiment, the pearl cotton can be fixed to the inner cavity of the first buffer box 21 or the second buffer box 22 by using foam glue or double-sided tape, so that the pearl cotton and the first buffer box 21 or the second buffer box 22 form an integrated structure. That is to say, in the present embodiment, the first buffer box 21, the second buffer box 22, the first box body 11, the second box body 12 and the anti-wear layer 30 are an integrated structure. Through the above arrangement, the packaging process of the air-conditioning indoor unit 2 can be greatly simplified.

[0067] It should be noted that since the first box body 11 and the second box body 12 are hinged, that is, the first box body 11 can rotate relative to the second box body 12, and the first buffer box 21 is arranged in the inner cavity of the first box body 11, and the second buffer box 22 is arranged in the inner cavity of the second box body 12, therefore, in the process of relative rotation of the first box body 11 and the second box body 12 to achieve covering, the first buffer box 21 and the second buffer box 22 may interfere with each other near the hinge between the first box body 11 and the second box body 12.

[0068] Optionally, in order to avoid interference between the first buffer box 21 and the second buffer box 22 during the rotation of the first box body 11 relative to the second box body 12, a side wall of the first buffer box 21 is provided with an escape groove 211 for evading the second buffer box 22, the escape groove 211 is close to the hinge between the first box body 11 and the second box body 12, and the depth direction of the escape groove 211 is parallel to the depth direction of the inner cavity of the first box body 11.

[0069] Optionally, the depth dimension of the avoidance groove 211 is within the range of 10 to 15 mm, and in this embodiment, the length dimension of a side wall of the first buffer box 21 on which the avoidance groove 211 is provided in the first direction may be less than, equal to, or greater than the dimension of the side wall of the first box body 11 in the depth direction of its inner cavity. In other words, Figure 2 or Figure 3For reference, the height dimension of one side wall of the first buffer box 21 on which the avoidance groove 211 is set can be less than, equal to or greater than the height dimension of the side wall of the first box body 11 close to one end of the second box body, and the height dimension of one side wall of the first buffer box 21 on which the avoidance groove 211 is set can be determined according to the specific depth dimension of the avoidance groove 211.

[0070] Optionally, at least one of the first buffer box 21 and the second buffer box 22 is provided with a material stealing hole 23 .

[0071] It can be understood that by providing the material stealing hole 23, the material on the first buffer box 21 or the second buffer box 22 can be saved, thereby achieving the effect of saving raw material costs.

[0072] Specifically, in this embodiment, the first buffer box 21 and the second buffer box 22 are both provided with a material stealing hole 23. It should be noted that the size of the material stealing hole 23 can be set according to actual conditions.

[0073] Furthermore, the first buffer box 21 includes a first end wall and a plurality of first side walls connected to the first end wall and connected end to end, and the second buffer box 22 includes a second end wall and a plurality of second side walls connected to the second end wall and connected end to end.

[0074] The thickness of the second side wall is the same as the thickness of the first end wall, and / or the thickness of the second side wall is the same as the thickness of the second end wall.

[0075] In other words, the thickness of each side wall of the first buffer box 21 is the same, and the thickness of each side wall of the second buffer box 22 is the same, so that each side wall of the accommodating cavity has a relatively uniform anti-seismic capability.

[0076] Of course, in some other embodiments, the thickness of each side wall of the first buffer box 21 may be different, and the thickness of each side wall of the second buffer box 22 may be different.

[0077] In summary, an embodiment of the present invention provides a packaging structure 1 for an air conditioner indoor unit, including a packaging box 10 and a buffer box. The packaging box 10 includes a first box body 11 and a second box body 12 that are hinged to each other. The buffer box includes a first buffer box 21 and a second buffer box 22, wherein the first buffer box 21 is fixedly connected to the inner cavity of the first box body 11, and the second buffer box 22 is fixedly connected to the inner cavity of the second box body 12. When the first box body 11 and the second box body 12 are covered, the first buffer box 21 and the second buffer box 22 are opposite to each other and form a receiving cavity for receiving the air conditioner indoor unit 2. Since the first buffer box 21 and the second buffer box 22 are respectively fixedly connected to the inner cavities of the first box body 11 and the second box body 12, when packaging the air-conditioning indoor unit 2, the operator only needs to place the air-conditioning indoor unit 2 in the first buffer box 21 or the second buffer box 22, and then rotate the second box body 12 relative to the first box body 11, so that the first box body 11 and the second box body 12 are covered, and the air-conditioning indoor unit is placed in the accommodating cavity, thereby simplifying the packaging process of the indoor unit 2.

[0078] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A packaging structure for an air conditioner indoor unit, characterized in that: include: A packaging box (10), the packaging box (10) comprising a first box body (11) and a second box body (12) which are hinged to each other; A buffer box, the buffer box comprising a first buffer box (21) and a second buffer box (22), the first buffer box (21) being fixedly connected to the inner cavity of the first box body (11), and the second buffer box (22) being fixedly connected to the inner cavity of the second box body (12); when the first box body (11) and the second box body (12) are covered, the first buffer box (21) and the second buffer box (22) are opposite to each other and form a receiving cavity for receiving the air conditioner indoor unit (2).

2. The packaging structure of the air conditioner indoor unit according to claim 1, characterized in that: The dimension of the side wall of the first box body (11) in the depth direction of its own inner cavity is smaller than the length dimension of the outer wall of the first buffer box (21) in the first direction, and the first direction is parallel to the depth direction of the inner cavity of the first box body (11).

3. The packaging structure of the air conditioner indoor unit according to claim 2, characterized in that: The difference between the dimension of the side wall of the first box body (11) in the depth direction of its inner cavity and the length dimension of the outer side wall of the first buffer box (21) in the first direction is in the range of 10 to 20 cm.

4. The packaging structure of the air conditioner indoor unit according to claim 1, characterized in that: An anti-wear layer (30) is provided in the inner cavity of at least one of the first buffer box (21) and the second buffer box (22).

5. The packaging structure of the air conditioner indoor unit according to claim 4, characterized in that: The anti-wear layer (30) is made of pearl cotton.

6. The packaging structure of the air conditioner indoor unit according to claim 4, characterized in that: The thickness of the anti-wear layer (30) is in the range of 0.5 to 1 mm.

7. The packaging structure of the air conditioner indoor unit according to claim 1, characterized in that: The side wall of the first buffer box (21) is provided with an avoidance groove (211) for avoiding the second buffer box (22); the avoidance groove (211) is close to the hinge between the first box body (11) and the second box body (12); and the depth direction of the avoidance groove (211) is parallel to the depth direction of the inner cavity of the first box body (11).

8. The packaging structure of the air conditioner indoor unit according to claim 7, characterized in that: The depth dimension of the avoidance groove (211) is in the range of 10 to 15 mm.

9. The packaging structure of the air conditioner indoor unit according to claim 1, characterized in that: At least one of the first buffer box (21) and the second buffer box (22) is provided with a material stealing hole (23).

10. The packaging structure of the air conditioner indoor unit according to claim 1, characterized in that: The first buffer box (21) comprises a first end wall and a plurality of first side walls connected to the first end wall and connected end to end, and the second buffer box (22) comprises a second end wall and a plurality of second side walls connected to the second end wall and connected end to end; The thickness of the first side wall is the same as the thickness of the first end wall, and / or the thickness of the second side wall is the same as the thickness of the second end wall.

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