Square-cylinder structure

Abstract

To provide a square-cylinder structure formable in various forms and usable in various applications, the square-cylinder structure being formed by an assembly without adhesion of a sheet material.SOLUTION: A face of a square cylinder is divided into two parts between right and left corners, and right and left divided faces 1a are extended inside the cylinder by folding from the respective divided parts. The structure has connection means for connecting extension faces 1b on both sides and comprises a connection member 2 according to the connection means or a lid part 1d provided with a connection part 1e. There is formed a square cylinder 1 obtained by connecting the extension faces 1b therewith and fixing the two divided faces 1a as one horizontal surface.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a rectangular cylindrical structure formed from a sheet material. [Background technology]

[0002] Square cylindrical objects made from cardboard or other thick paper sheets are usually formed into a square cylindrical shape by gluing the surfaces together, which requires processes such as cutting and scoring the sheet material, as well as a gluing process. Normal cardboard boxes are formed by folding the bottom and lid. Among cardboard boxes, there is a picture-frame type, which is formed only by assembling without gluing. These cardboard boxes are used as packaging materials and storage boxes. Furthermore, when paper square tubes are used for the pillars or legs of furniture, strong paper tubes that have already been formed into square tubes are generally used, with plastic being used for the joints.

[0003] In terms of square tube-shaped products made from sheet material, Patent Document 1 proposes an expandable structure using square tubes. Patent Document 2 proposes a packaging box formed without adhesives. Patent Document 3 proposes a pallet beam made of two joined square tubes. Patent Document 4 proposes a packaging member made of two joined square tubes. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent 7109037 [Patent Document 2] Actual opening Showa 47-004126 [Patent Document 3] Utility model registration No. 3227248 [Patent Document 4] Patent 4719548 Summary of the Invention [Problem to be solved by the invention]

[0005] When packing items into cardboard boxes, the items are lifted up and placed in the box, but if the box is too small, it is not easy to fit the item inside, and if there is too much space, the item will rattle inside the box and will not be protected, so cushioning material is used. Also, no matter what shape the item is, it is usually packed in a rectangular box, which creates wasted space inside the box. In the case of frame-type boxes, there are many assembly steps, such as inserting to form the frame and inserting to put on the lid, and it is not easy to disassemble. Although the cardboard tubes used in furniture are lighter than wood and can be recycled, the joints are not a renewable material. Also, cardboard tubes are pre-formed into a shape and take up space just like wood.

[0006] In (Patent Document 1), the lever, elastic section, and other parts are formed without adhesion, and the inside is divided to fix them, but the divided parts inside the sliding section and the storage section are formed by adhesion. In this case, there is a possibility that misalignment may occur during adhesion. This may cause the operation to become less smooth, but once something is glued, it cannot be undone.

[0007] (Patent Document 2) is easy to assemble without gluing, but the folded parts of the divided surfaces are extended diagonally inside to form a triangle. An article is fixed in this by providing a hole. However, in order to fit the article in the hole, it is necessary to leave space in front and behind, and the shape is designed for this article. Also, although it is fixed and does not wobble, it does not provide cushioning for the top and sides.

[0008] (Patent Document 3) is a product that is glued to the top and bottom plates, and because it is made of paper, when a lateral force is applied to the top surface, the rectangular cross section of the product is deformed into a parallelogram, and since the separation prevention member cannot suppress this deformation, the product tilts diagonally, and one corner of the product protrudes from the insertion opening. Therefore, it must be fixed by glue, and its use is limited to pallets.

[0009] In (Patent Document 4), two square tubes are sandwiched and fixed, but they are sandwiched between two notches in a U-shaped auxiliary member, and without the auxiliary member, the tubes cannot be fixed, and there is no other way. In addition, as a packaging member, two square tubes must be sandwiched, and the aim is to increase the strength by using two square tubes, not to form a single square tube. Furthermore, the cross section must be a square, and cannot be a polygon such as a triangle or pentagon. Therefore, the shape cannot be changed according to the purpose of use, the opening can be closed, the inside can be used, or the appearance can be improved.

[0010] In view of the problems of the prior art as described above, the present invention aims to provide a rectangular cylindrical structure made of cardboard sheets that can be assembled without gluing, can be formed into various shapes as a rectangular tube, and can be used for various purposes. When used to store items, the rectangular cylindrical structure can be easily packed in a size and shape that matches the items, and can also serve as a cushioning material. [Means for solving the problem]

[0011] All parts are made of cardboard or cardboard A square tube-shaped structure formed by assembly without bonding sheet material, one of whose faces is divided into two between the left and right corners, and the left and right divided faces are each extended inside the tube by folding the divided parts, and has a joining means for tightly fitting, fixing and joining the extended faces on both sides, and is provided with a joining member that has a joining function according to the joining means and can be a separate member inserted into the square tube and can be in the form of a lid to close the opening at the end of the square tube, or a lid portion that closes the opening and is provided by extending either the outer face of the square tube or the face extended on the inside.

[0012] A protrusion is provided on each of the extended surfaces on both sides, which is folded outward and fitted closely to the outside, and is inserted into the inside of the extended surface on the opposite side in a fitted state, and a fixing portion provided on the protrusion that engages with the extended surface on the opposite side brings the extended surfaces on both sides into close contact, fixes them, and joins them.

[0013] A collection of rectangular tubes of different shapes can be formed by extending the entire sides or parts of the sides of some of the outer faces and the extended faces of the rectangular tube vertically or horizontally, changing the place of folding, or transforming the shape into one in which new folding can be added.

[0014] The cross section of the square tube is a right triangle, the opposite side of the right angle is divided into two, and the extended surface is fixed at the right angle. A joining member is provided to simultaneously join the extended surface and the two square tubes with the divided surfaces in close contact with each other, and the joining member can be used to join a plurality of square tubes together and extend them in the opposite direction.

[0015] The extension surface is fixed to the opposite side of the dividing surface, and two notches that do not contact either surface are provided between the dividing surface and the opposite surface. A joining member is inserted into the notch and can maintain the cross-sectional shape of the square tube while fixing the dividing surface as a single surface. By using the joining member, which can also be joined in the opposite direction, multiple square tubes can be joined and extended, and extension in multiple directions is also possible by using a connecting member that can change the angle in another direction.

[0016] The extension surface is folded back once more toward both side surfaces of the dividing surface, a protrusion is provided at the tip of the folded surface, and both side surfaces are provided with notches or holes to which the protrusion is fixed, forming a space between the dividing surface and the folded surface the thickness of the sheet material, a notch is provided between the two folds of the dividing portion, and a joining member or a lid portion with a joining function is provided, which is inserted into the space the thickness of the sheet material and fixes the dividing surface as one surface.

[0017] The protrusion and the hole to which the protrusion is fixed are provided between both ends of the square tube, and a hole is also provided between the two folds of the divided part at the same position, and a joining member that penetrates the divided surface is inserted from one side of the hole to which the protrusion on the side is fixed.

[0018] A protrusion that rises and protrudes in the direction opposite to the insertion direction is provided in the insertion portion of the joining member or the lid portion by folding, and a hole is provided on the surface into which the insertion portion is inserted, corresponding to the position of the protrusion, through which the protrusion protrudes and engages.

[0019] By using the above-mentioned joining member, which has two opposing surfaces that are divided into two and can be joined in the opposite direction, it is possible to join and extend multiple square tubes.

[0020] The lower ends of the two undivided faces are joined to form the base.

[0021] The two undivided surfaces are each provided with a protruding piece that is folded inward and closely adheres to the surface, and one of the protruding pieces is provided with a locking protruding piece, while the other protruding piece is provided with a locking hole or notch.

[0022] All surfaces of the square tube are divided into two, and the opening at the end of the square tube is covered with two lid-shaped joining members so that there is a space between the inside and outside equal to the thickness of the joining members. All surfaces, including the covered surfaces, have a three-layer structure consisting of an inner sheet material, the joining members or a space equal to the thickness of the joining members, and an outer sheet material.

[0023] A polygon with all right angles and at least one concave angle. Effect of the Invention

[0024] According to the present invention, rectangular cylindrical structures can be formed in various shapes by assembling them without gluing cardboard sheets, enabling them to be used for a variety of purposes and saving space and resources when packaged. [Brief description of the drawings]

[0025] [Figure 1] This is an example of the shape of a rectangular cylindrical structure, with one side divided and a cutout provided on the internal extended surface. A is an oblique view and developed view of the structure joined with a connecting member, B is an oblique view and developed view of the structure with the extended portion shortened and a lid portion provided, and C is an oblique view and developed view of the structure with the extended portion shortened and joined with a lid-shaped connecting member. [Diagram 2] The figures show an example of the shape of a rectangular cylindrical structure, with one side divided and a protrusion provided on the internal extended surface. A is an oblique view and developed view of the extended portion shortened and cut out, with a hole provided in the lid, B is an oblique view and developed view of the lid with a hole and cutout, and C is an oblique view and developed view of the structure joined with a lid-shaped joining member. [Diagram 3] This is an oblique view and an exploded view of an example of a rectangular cylindrical structure in which one side is divided and four rectangular tubes are attached to a lid-shaped connecting member. [Figure 4] This is an example of the shape of a rectangular cylindrical structure, with one side divided and a lid provided on the extended surface. A is an oblique view and developed view of the lid provided on one side of the extended surface folded back to face each other, and B is an oblique view and developed view of the lid provided on both extended surfaces. [Diagram 5] This is an example of a rectangular cylindrical structure in which one side is divided and a lid is provided on the side. A is an oblique view and an unfolded view of the structure joined at the insertion part, and B is an oblique view and an unfolded view of the structure joined at the lid. [Figure 6] This is an oblique view and an exploded view of an example of a rectangular cylindrical structure in which one side is divided and protrusions are provided on the outside of the extended sides on both sides. [Figure 7] Examples of shapes of rectangular cylindrical structures: A is a perspective view of a triangular cross section, and B is a perspective view of a pentagonal cross section. [Figure 8] Examples of shapes of rectangular tubular structures: A is an oblique view of the extended surface, the outer surface extended vertically; B is an oblique view of a divided surface with a step; and C is an oblique view of a rectangular tube with a small rectangular tube extending downward at the corner of the rectangular tube. [Figure 9] This is an example of a rectangular cylindrical structure, in which two rectangular tubes with triangular cross sections are joined together. A is a perspective view of the assembly, and B is a perspective view of the joining parts joined in both directions. [Figure 10] This is an example of a shape of a rectangular cylindrical structure with two notches on the extended surface. A is an oblique view of the joining member joined in both directions, B is an exploded view of the joining member, and C is an oblique view of the joining with a lid-shaped member. [Figure 11] This is an example of the shape of a rectangular cylindrical structure, which is extended from vertical to horizontal using connecting parts, where A is a perspective view of the assembly and B is an exploded view of the connecting parts. [Figure 12]This is an example of a rectangular cylindrical structure that is extended horizontally at a right angle using a connecting member, where A is an oblique view of the assembly and B is an exploded view of the connecting member. [Figure 13] This is an example of a rectangular cylindrical structure with connecting members extending in three directions, where A is an assembled perspective view and B is an exploded view. [Figure 14] FIG. 13 is a perspective view of an example of a rectangular cylindrical structure, showing an assembly using connecting members extending in three directions. [Figure 15] This is an example of the shape of a rectangular cylindrical structure, with the dividing surface folded back. A is an oblique view and developed view of the structure joined with a joining member, B is an oblique view and developed view of the structure joined with a joining member that penetrates the dividing surface, and C is an oblique view and developed view of the structure with a lid portion provided. [Figure 16] FIG. 13 is a diagram showing an example of the shape of a rectangular cylindrical structure, with A being a perspective view and B being a front view, showing the fixing of an insertion part. [Figure 17] An example of the shape of a square cylindrical structure, and an expanded view when used as packaging material. [Figure 18] FIG. 13 is a perspective view of an example of a rectangular cylindrical structure, showing its assembly when used as a packaging material. [Figure 19] FIG. 1 shows an example of a rectangular cylindrical structure with two divided faces. A is a perspective view of the two faces joined with joining members, B is a perspective view of the two faces joined on both sides with joining members, and C is a perspective view of the faces joined with a lid-shaped joining member. [Figure 20] This is an example of a rectangular cylindrical structure in which two sides are divided and a bottom surface is provided. A is a perspective view of the two sides joined with joining members, and B is an exploded view. [Figure 21] The diagram shows an example of a rectangular cylindrical structure with a thin, long space. A is a perspective view of a method for fixing the spacing at a constant value, and B is an exploded view. [Figure 22] This is an example of the shape of a rectangular cylindrical structure, with all faces divided. A is an oblique view of the inner and outer lid-shaped connecting members, and B is an oblique view and an exploded view of the rectangular member. [Figure 23] FIG. 13 is a perspective view of an example of a rectangular cylindrical structure in which all faces are divided and concave corners are provided. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0026] Hereinafter, an embodiment of the present invention will be described. The rectangular cylindrical structure of the present invention is made of cardboard. or cardboard The sheet material is processed by die cutting, scoring, etc., and can be easily assembled by folding. The basic structure is as shown in Figure 1A, where one surface of a square tube 1 is divided into two between the left and right corners, and the two divided surfaces 1a are each extended inside the square tube 1 by folding the divided portion. Then, a joining member 2 is inserted into a notch 1c, the thickness of the sheet material, provided in the part of extended surface 1b that contacts the folded portion of the divided portion, to join the left and right extended surfaces 1b in close contact with each other and fix the two divided surfaces 1a into a single horizontal surface. The joining member 2 has a notch 2a that sandwiches the left and right extended surfaces 1b below the notch 1c. In this case, when force is applied to the dividing surface 1a, the dividing portion will bend inward, so the extension surface 1b is extended to the opposite side of the dividing surface 1a, a protrusion is provided at the tip, and it is locked and fixed in place by a notch provided on the opposite side. It is not necessary to extend the entire extension surface 1b, and only the part where the locking point is provided may be extended. The locking point does not have to be the end, in which case it will be a hole rather than a notch. Also, the joining member 2 may be inserted obliquely downward from the opposite side of the extension surface 1b toward the dividing surface 1a, and a notch 1c may be provided on the extension surface 1b so that the tip of the joining member 2 is engaged with the dividing surface 1a. This can increase the strength from the side.

[0027] In Figure 1B, a lid 1d is provided on the opposite side of the dividing surface 1a, and an insertion part 1e with a notch 1f, similar in shape to the joining member 2, is provided at the tip of the lid 1d, which is inserted into the notch 1c and the extended surface 1b is tightly attached and joined to close the opening at the end of the square tube 1. In this case, the lid 1d prevents the dividing part from being depressed inwards, so the extended surface 1b can be shortened without extending to the opposite side. By shortening it, the material can be made smaller. In Fig. 1C, a lid-shaped joining member 2 with an insertion part 2b having a notch 2c on the dividing surface 1a side and an insertion part 2b without a notch on the opposite side is inserted into the notch 1c and joined by closely contacting the extended surface 1b. In this case, the extended surface 1b can be shortened as in Fig. 1B, but if it is made short as in Fig. 1C, the opposite side of the joining member 2 will sink into the square tube 1, so as in Fig. 1C, a protrusion is provided on the opposite side or the extended surface 1b is made long enough so that it does not sink. In both Figures 1B and 1C, the strength can be increased by extending the extended surface 1b to the opposite side as in Figure 1A. In this case, in Figure 1C, the opposite side of the joining member 2 is an insertion part 2b with a notch 2c, and a notch is also provided in the extended surface 1b, and joining is performed on both sides.

[0028] The joining means can be not only sandwiching the extended surface 1b with the notch, but also fixing with a hole 1g provided in the lid portion 1d and a protrusion 1h provided on the extended surface 1b as shown in Fig. 2A. The protrusion 1h is inserted into the hole 1g, and the left and right extended surfaces 1b are fixed and joined in a state of close contact. In this case, the insertion part 1e of the lid portion 1d does not need to have a joining function. Also, the extended surface 1b does not need to extend to the opposite side. As shown in Figure 2B, it is also possible to simply sandwich the extension surface 1b between the insertion portion 1e divided into two by the notch 1f without providing the notch 1c in the extension surface 1b. This eliminates the gap caused by the notch 1c in the divided portion, improving the appearance. However, this may result in a step in which the left and right divided surfaces 1a are not fixed as a single surface, so as shown in Figure 2B, a protrusion 1h is provided on the opposite side of the extension surface 1b, and a hole 1g is provided in the lid portion 1d to fix the extension surface 1b. Fig. 2C shows a lid-shaped joint member 2 with insertion parts 2b at two places, the dividing surface 1a side and the opposite side, and protrusions 1h on the dividing surface 1a side and the opposite side of the extended surface 1b are inserted into notches 2c extending from the insertion parts 2b to the top surface, and the extended surface 1b is brought into close contact and fixed for joining. Even if there is only the top surface without the insertion parts 2b, the protrusions 1h can be fixed in the notches 2c, and the cross-sectional shape of the square tube 1 can be maintained. This type of form can be used as a simple or temporary solution, since it is not fixed on the top surface alone and is easy to come off.

[0029] In Figure 3, the extension surface 1b does not have a notch 1c, and the insertion parts 2b on both sides of the lid-shaped joining member 2 are extended and rolled up to form two square tubes for joining, one on each side. The cross section of the joining square tube sandwiches the extension surface 1b, tightly contacting and fixing it. This increases the strength against lateral loads. Also, the strength can be further increased by extending the insertion parts 2b and overlapping them on the inside in two or three layers. Fig. 4 shows a case where a lid 1d is provided on an internally extended surface. In Fig. 4A, both extended surfaces 1b are folded back to the side facing each other, and a lid 1d is provided extending upward on one of the folded surfaces 1i. The joint is made by sandwiching a protrusion 1h on the extended surface 1b with a notch 1f extending to the top surface of the lid 1d, and no notch is provided on the extended surface 1b. The component becomes larger, but while it is formed from a single component, it has a good appearance with no gaps caused by the notch. In Fig. 4B, lids 1d are provided on both extended surfaces 1b, which cross each other toward the opening on the opposite side, and are tightly attached by sandwiching the protrusion 1h of the extended surface 1b on the opposite side to cover the opening on the opposite side.

[0030] As shown in Fig. 5, the lid 1d can be provided on the side of the dividing surface 1a instead of on the opposite side. In Fig. 5A, the insertion part 1e is curved to allow insertion, and is joined at the notch 1f of the insertion part 1e. In Fig. 5B, it is joined at the notch 1f of the lid 1d. The lid 1d can also be provided on the dividing surface 1a. In this case, it is in the form shown in Fig. 4A, and a notch 1f is also provided on the dividing surface 1a side. Also, they can be joined not at the ends but at the middle of both ends. As shown in Fig. 6, the extension surfaces 1b on both sides are folded so that they protrude outward, and protruding pieces 1j are provided on each of the extension surfaces 1b on both sides, which are brought into a state of close contact by the reaction of the folding. Each protruding piece 1j is provided with a fixing part 1k that crosses each other by folding, and is inserted into the inside of the extension surface 1b on the opposite side in a close contact state. At this time, the fixing parts 1k are inclined so that they do not get caught on each other. As a result, the fold of the fixing part 1k is stretched while it is inserted, and after insertion, the fold is returned by the reaction and it is caught and fixed on the extension surface 1b on the opposite side. In this way, the extension surfaces 1b on both sides are joined in close contact. Since this form does not maintain the cross-sectional shape of the square tube 1, it is recommended to use it in combination with the joining at the ends when the square tube 1 is long. If the square tube 1 is formed in advance in this form, it is easier to insert the lid-shaped joining member 2. As described above, there are various joining methods, and the extended surfaces 1b on both sides are joined by tightly contacting them with a notch, a hole, or the cross section of the square tube. For joining, a separate joining member 2 is used, or a lid portion 1d is used that is provided on either the outer surface of the square tube 1 or the inner extended surface of the square tube 1, allowing the square tube 1 to be formed in various shapes and to be used for various purposes and in various conditions.

[0031] The cross section of the rectangular tube 1 can be a polygon such as a triangle or pentagon as shown in Fig. 7. The extension surface 1b can also be freely shaped by simply fixing a part of it in close contact as shown in Fig. 7B. As shown in Fig. 8A, one square tube 1 can be made into an assembly of multiple square tubes of different shapes by changing the left and right lengths of the dividing surface 1a and changing the heights of the extended surface 1b and the outer surface. As shown in Fig. 8B, the dividing surface 1a can be stepped and part of the extended surface 1b can be made the outer surface to form a concave corner. In Fig. 8C, a small square tube 1 with a dividing surface 1a extending downward is formed at each corner of one square tube 1. In this way, it can be made into various forms. The ones in Figs. 8A and B can be used as a storage box by utilizing the inside, and the one in Fig. 8C can be used as a stand for placing items.

[0032] As shown in Figure 9A, two square tubes 1 with a cross section of a right triangle, the opposite side of the right angle being divided into two, and the extended surface 1b fixed at the right angle can be attached to each other at their divided surfaces 1a, and a joining member 2 that joins the two square tubes 1 can be inserted into the notches provided in the divided surface 1a and the extended surface 1b of each square tube 1, resulting in a square tube 1 with a cross section of a square. This results in a double sheet material crossed inside, making it strong against loads. Also, as shown in Figure 9B, the joining member 2 can be made to be able to be joined in the opposite direction, and multiple square tubes 1 can be connected and extended.

[0033] In Fig. 10A, the extension surface 1b is fixed opposite the dividing surface 1a, two notches 1c are provided on the extension surface 1b on the inside not facing the dividing surface 1a, and the joining member 2 is inserted into the two notches 1c to join the extension surface 1b while providing protruding pieces 2d that hold down the four corners to maintain the cross-sectional shape of the square tube 1. It is also possible to join in the opposite direction, so that multiple square tubes 1 can be connected and extended. When putting on a lid, a joining member 2 of the same form as in FIG. 2C is used as in FIG. 10C. No notches are used, but the space between the two notches is lowered by the thickness of the sheet material, so that the extended surfaces 1b in contact with both sides are joined and the cross-sectional shape is also fixed.

[0034] This configuration can extend in multiple directions, not just vertically or horizontally. In Figure 11, a right-angled connecting member 3 with the dividing surface 1a as the inner angle is used to extend from the vertical to the horizontal direction. To fix the inner angle of the connecting member 3, a protrusion 4a at the tip of the fixing member 4 is inserted into a hole 3a provided in the extension of the inner angle. It is fixed doubly from both the vertical and horizontal directions. In Fig. 12, the dividing surface 1a is extended horizontally using a connecting member 3 perpendicular to the horizontal direction with the upper surface horizontally horizontal. In this case, a fixing member 4 having a protrusion 4c with a hole 4b at its tip is inserted into a hole 3a provided in the extended part of the inner angle, and another fixing member 4 having a protrusion 4a is inserted perpendicularly into the hole 4b to provide doubly fixed connection. In Figures 13 and 14, a member that can be connected vertically is attached to the corner of Figure 11. This is also fixed by inserting the protrusions 4a at the tip of the fixing member 4 from both sides into the holes 3a provided in the extension of the inner corner. This allows for extension in multiple directions. Conventional furniture and other items would use plastic parts for such connections, but this can now be made using only cardboard or other thick paper materials.

[0035] The interior of the rectangular cylindrical structure of the present invention can also be used effectively. In Fig. 15A, the dividing surface 1a is folded inward at the dividing portion, and the extended portion is folded again and folded back in the lateral direction. A notch 1c is provided between the two folds of the dividing portion. A protrusion is provided at the tip of the folded surface 1i, and a notch 1m is provided at the corners of both sides. The protrusion at the tip of the folded surface 1i engages with this notch 1m, and the dividing surface 1a and the folded surface 1i are fixed so that a space equivalent to the thickness of the sheet material is formed between them. The joining member 2 is inserted into this space, and the part below the notch 1c is sandwiched and joined. As a result, the dividing surface 1a is fixed as a single flat surface. It is recommended to provide a protrusion equivalent to the notch 1m on both the left and right sides of the joining member 2. In Fig. 15B, the protrusion at the tip of the folded surface 1i is placed between both ends rather than at the end of the square tube 1, holes 1n are placed instead of notches on both sides, a hole 1o is placed between the two folds of the left and right divided parts, and a joining member 5 is inserted through the hole 1n on one side that penetrates the divided surface 1a, joining the divided surface 1a as a single flat surface. This type of joining is also possible when the square tube 1 is long. If the holes 1n are close together, it is not necessary to place notches 1m on both ends.

[0036] In Figures 15A and 15B, the space between the dividing surface 1a and the folded surface 1i is set to the thickness of the sheet material, which maximizes the space inside. However, there is not enough room to insert the joining member 2, and it is not easy. Therefore, in Figure 15A, the outer dividing surface 1a is folded, the space is expanded to the outside at the cutout 1c, and the tip where the joining member 2 is inserted is sharpened to make it easier to insert. In Figure 15B, the folded surface 1i is folded and expanded to the inside. It can be either on the outside or the inside, and if you want to use the inside space to the maximum, you should choose the outside, and if you want to have some space on the inside and keep the outside flat, you should choose the inside. Fig. 15C shows a case where a lid portion 1d is provided, which is basically the same as Fig. 15A, but the folded surface 1i and both side surfaces are lower than the divided surface 1a by the thickness of the lid portion 1d, so that the height of the top surface of the lid portion 1d and the upper part of the divided surface 1a are aligned. Since a step is created between the divided surface 1a and the folded surface 1i, and a notch 1m is provided at the corner with the side surface, when inserting the inserting part 1e, the step can be used to spread the upper part of the divided surface 1a outward with the tip of the inserting part 1e, and it can be inserted without spreading it by folding it as in Figs. 15A and B. Since it is sufficient to spread the upper part of the divided surface 1a outward in this way, it is also possible to spread it in the same way in the form shown in Fig. 15B by providing a step and making a slit instead of a notch at the corner of the side surface.

[0037] When using the square tube 1 for storage or packaging and wanting to prevent the bottom from falling out or the lid from opening by itself, there is an easy way to fasten the lid 1d as shown in Figure 16. A protruding piece 1p is provided on the notch of the insertion part 1e by folding it up and protruding in the opposite direction to the insertion direction, and a hole 1q is provided in the part of the division surface 1a where the protruding piece 1p is located, the hole being made to match the size of the protruding piece 1p. The protruding piece 1p is folded up before inserting the insertion part 1e, and when the insertion part 1e is inserted, the protruding piece 1p falls down once when it is inserted, but when it reaches the hole 1q, it stands up due to the reaction of folding, and is caught and locked on the cross section of the hole 1q. In this way, the protruding piece 1p can be easily fixed by simply folding it and inserting it. To release the lock, the protruding piece 1p can be easily released by simply pushing the protruding piece 1p with a fingernail to remove the catch. The strength of the fixation can be increased by increasing the width of the protruding piece 1p.

[0038] This fixing method may be not only the lid 1d but also the joining member 2, and when fixing the bottom surface of the storage box, it may be provided on the folded surface 1i side that cannot be seen from the outside. In this way, it is not limited to the dividing surface 1a, but can be provided on the inserting surface and the inserted surface. When provided on the lid 1d, a protrusion 1r may be provided at the corner of the insertion part 1e to make it easier to pull out the insertion part 1e. A notch 1s is provided at the end of the square tube on the dividing surface 1a side to make it easier to insert a finger and lift the protrusion 1r. In this case, the corner of the notch in the insertion part 1e is sloped so that it does not get caught on the corner of the notch 1s. If it is to be used as packaging material to make it difficult to open, a sticker or the like may be attached to the hole 1q.

[0039] The square tube 1 can be used as a packaging material. When packaging in a normal box, it is difficult to insert and remove items that are the same size as the inside of the box. However, the square tube 1 of the present invention can be used to package items by wrapping them in wrapping paper, rather than putting them in a box. Items are packaged using a sheet material such as that shown in Figure 17, with the inside dimensions being the same as the outside dimensions of the item. Inner lids may be provided on the top and bottom sides. As shown in Figure 18, an item 6 is placed on the square tube 1 in the form of a sheet material, the sheet is folded, the divided surface 1a is aligned to encase the item, a lid is placed on the bottom, the tube is then stood up, and the top lid is put on to complete the package. If the divided surface 1a is placed on the top, there is no need to stand it up, making packaging easier. To remove the item 6, simply release the insertion portion 1e and the tube can be easily unfolded back into the original sheet material. This allows the sheet material to be stored and used multiple times.

[0040] The square tube 1 can be made of two sheets of material by dividing the two opposing surfaces into two. In this case, the dividing surface 1a is folded back in two as shown in Figure 19A. The two opposing surfaces become a double layer of dividing surface 1a and folded back surface 1i, making it strong against loads. The connecting members 2 are inserted into the two sides, but as shown in Figure 19B, each connecting member 2 can be connected in the opposite direction to connect and extend multiple square tubes 1. When attaching a lid, two connecting members 2 are connected at the top as shown in Figure 19C.

[0041] When the two opposing faces of the square tube 1 are divided into two, the bottom ends of the two undivided faces can be joined to form the bottom surface 1t, as shown in Figure 20. In this case, by providing a protrusion at the bottom end of the folded surface 1i and fixing it in a notch in the bottom surface 1t, and maintaining a space equivalent to the thickness of the joining member 2, it becomes unnecessary to insert the joining member 2 below the divided surface 1a. In this way, a square tube 1 with a bottom surface 1t can be formed using fewer parts. In this case, as shown in FIG. 20, the outer height of the entire part is made uniform, the folded surface 1i is inclined toward the dividing portion, and a step is provided between the folded surface 1i and the dividing surface 1a, thereby making it easier to insert the joining member 2. This form can also be made to have a thin and long space as shown in Figure 21, allowing storage in a small space. If it is made thin and long, the longer it is, the more the middle part bulges outward, and the space between the faces will not be uniform. To make this uniform, as shown in Figure 21, a protrusion 1u is provided on both sides of the middle part, which becomes attached to both sides at right angles in reaction to folding. A hole 1v is provided on one side of this protrusion 1u, and a protrusion 1w is provided on the other side that protrudes into this hole 1v when folded. The cross section of protrusion 1w engages with the cross section of hole 1v, fixing the space between the faces. This protrusion 1u can also be used as a partition.

[0042] All of the faces of the square tube 1 can also be divided, in which case all faces can have a three-layer structure consisting of an inner sheet material, a joining member 2 or a space equivalent to the thickness of the joining member 2, and an outer sheet material. As shown in Figure 22, the joining member 2 is made into two lid-shaped members, an inner and an outer one, and by joining each of the two opposing faces in different directions, all of the faces, including the lid, become a three-layered box. The square tube 1 is made up of four corner members, and joining members 2 are inserted at the top and bottom ends of corner member 7, giving each face a different height to create a three-layered structure, and this is combined with corner member 8, which has a vertically inverted shape. The inner joining member 2 has a protrusion 2e to maintain a space between it and the outside, the equivalent of the thickness of the sheet material. As a result, when an article is packed, even an article having the same dimensions as the inner dimensions can be protected by the three-layer structure without the need for cushioning material.

[0043] If the corners are all right-angled polygons, the corner pieces can be turned over and used as concave corners, making it possible to make polygons with concave corners, such as an L-shape as shown in Figure 23, rather than the usual polygon with only convex corners. As shown in Figure 23, an inverted concave corner member 9 is joined to a normal corner member to create a surface with a concave corner. Surfaces with concave corners are difficult to assemble separately, so it is a good idea to use joining members 5 that penetrate the surface to unite them together. The ends of concave corner member 9 should be the same height as the corner members to be joined and each of the surfaces. Joining members 2 are then inserted at both ends to form a polygon with concave corners. If necessary, provide fixing points as shown in Figure 16. In this way, various polygonal shapes can be formed, and what would normally be packed in a square box that is larger than the item and has wasted space can be packaged in a box that matches the shape of the item, resulting in space-saving, resource-saving packaging that can be reused multiple times. [Explanation of symbols]

[0044] 1 square tube 1a Split plane 1b Extension surface 1c Extension surface cutout 1d Lid 1e Lid insertion part 1f Lid cutout 1g Hole in the lid 1h Extension surface protrusion 1i Folded surface 1j Extension surface protrusion 1k Fixing part of the extension surface protrusion 1m Side cutout 1n Side hole 1o Hole between two folds 1p Protruding piece 1q Hole from which a protrusion protrudes 1r Corner protrusion of insertion part 1s Cutout at the end of the square tube 1t bottom 1u Middle protrusion 1v Hole in protrusion 1w Protrusion of a protruding piece 2 Joining materials 2a Notch in joint member 2b Insertion part of joining member 2c Notch extending to the top surface of the joining member 2d Protruding piece of joining material 2e Protrusion of inner joint member 3 Connection parts 3a Hole in the extension of the inner corner of the connecting member 4 Fixing member 4a Protrusion at tip of fixing member 4b Hole in fixing member 4c Protrusion with hole for fixing member 5 Joint members penetrating the dividing surface 6 Goods 7 Corner members 8 Inverted corner members 9 Concave corner members

Claims

1. A rectangular tube-shaped structure in which all parts are assembled without bonding thick paper sheet materials such as cardboard or cardboard, one of whose sides is divided into two between the left and right corners, and the left and right divided surfaces are each extended inside the tube by folding the divided parts, and which has a joining means for tightly fitting, fixing and joining the extended surfaces on both sides, and which is equipped with a joining member that can be formed into a lid-like form to close the opening at the end of the rectangular tube, which is a separate member inserted into the rectangular tube and has a joining function according to the joining means, or a lid portion that closes the opening, which is provided by extending either the outer surface of the rectangular tube or the surface extended on the inside.

2. In the rectangular cylindrical structure of claim 1, a protrusion is provided on each of the extended surfaces on both sides that is folded outward and tightly attached, and in a tightly attached state, is inserted into the inside of the extended surface on the opposite side, and a fixing portion that engages with the extended surface on the opposite side provided on the protrusion is provided to tightly attach and fix the extended surfaces on both sides to each other.

3. 2. The rectangular tubular structure according to claim 1, wherein some faces of the rectangular tubular structure can be deformed by extending vertically or horizontally to form an assembly of rectangular tubes of a plurality of different shapes.

4. In the rectangular cylindrical structure of claim 1, the cross section is a right-angled triangle, the opposite side of the right angle is divided into two, and two rectangular tubes have the extended surfaces fixed at the right angle portions, and the divided surfaces are in close contact with each other and a joining member is provided to simultaneously join the extended surfaces to the two rectangular tubes, and the joining member can also be used to join in the opposite direction, thereby making it possible to join multiple rectangular tubes together and form an extendable rectangular cylindrical structure.

5. In the rectangular tube structure of claim 1, the extension surface is fixed to the opposite side of the dividing surface, two notches are provided between the dividing surface and the opposite side that do not contact either surface, and a joining member is inserted into the notch and can maintain the cross-sectional shape of the rectangular tube while fixing the dividing surface as a single surface, and by using the joining member which can also be joined in the opposite direction, a plurality of rectangular tubes can be joined and extended, and by using a connecting member which can change the angle in another direction, the rectangular tube structure can also be extended in multiple directions.

6. In the angular tubular structure of claim 1, the extended surface is folded back once more toward both side surfaces of the dividing surface, a protrusion is provided at the tip of the folded surface, and both side surfaces are provided with notches or holes to fix the protrusions and form a space between the dividing surface and the folded surface equivalent to the thickness of the sheet material, a notch is provided between the two folds of the dividing portion, and the angular tubular structure is provided with a joining member that is inserted into the space equivalent to the thickness of the sheet material to fix the dividing surface as a single surface, or a lid portion with a joining function.

7. In the rectangular tubular structure of claim 6, the protrusion and the hole to which the protrusion is fixed are provided between both ends of the rectangular tube, a hole is also provided between the two folds of the divided portion at the same position, and a joining member that penetrates the divided surface is inserted from one side of the hole to which the protrusion on the side is fixed.

8. In the angular tubular structure of claim 6, a protrusion that protrudes upward in the direction opposite to the insertion direction by folding is provided in the insertion portion of the joining member or the lid portion, and a hole through which the protrusion protrudes and engages is provided in the surface into which the insertion portion is inserted, in accordance with the position of the protrusion.

9. 9. The rectangular tubular structure according to claim 6 or 8, wherein the two opposing faces are divided into two, and the joining member can be used to join a plurality of rectangular tubes together to form an extendable rectangular tubular structure, which can be joined in opposite directions.

10. 10. The rectangular tubular structure according to claim 9, wherein the bottom surface is formed by connecting the lower ends of the two undivided faces.

11. The rectangular tubular structure of claim 10, wherein each of the two undivided sides has a protrusion that is folded inward and tightly attached, and the protrusion on one side has a locking protrusion and the protrusion on the other side has a locking hole or notch.

12. A square tube structure according to claim 6 or 8, in which all of the faces of the square tube are divided into two, the openings at the ends of the square tube are covered with two lid-shaped joining members so that there is a space between the inside and outside equal to the thickness of the joining members, and all of the faces, including the covered faces, have a three-layer structure consisting of an inner sheet material, the joining members or a space equal to the thickness of the joining members, and an outer sheet material.

13. 13. The rectangular tubular structure of claim 12, wherein all corners of the rectangular tubular structure are polygonal, and one or more corners are concave.

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