Container

Abstract

To reduce the number of parts constituting a container.SOLUTION: A container is provided with: a container body 10 provided with side wall parts 11 and a bottom wall part; frame members 20 attached along at least one end edge of an upper end edge and a lower end edge of the side wall part 11; a corner member 30 fixed on an end edge on which the frames 20 are attached so as to cross over a pair of side walls 11 adjacent to each other. A limiting part 36 limiting movement of the frame member 20 in a vertical direction with respect to the corner member 30 is integrally provided on the corner member 30.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a container. [Background technology]

[0002] There are known containers for sorting and storing parts used in factories or for sorting and storing products to be sold in stores. In order to improve the convenience of such containers, they may be formed using hollow plate materials that are lightweight and have appropriate strength.

[0003] Patent Document 1 describes an invention relating to a container that uses a plastic corrugated cardboard sheet as the material for the peripheral wall. The container described in Patent Document 1 is assembled by folding a plastic corrugated cardboard sheet cut to a specified size along linear creases formed at specified positions. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2013-14378 A Summary of the Invention [Problem to be solved by the invention]

[0005] By the way, a hollow board material such as a plastic corrugated board sheet is composed of two layers of layered sheets and a support member connecting them. Therefore, the gap formed between the two layers of layered sheets is exposed on the cut surface. As a result, it becomes easy for dirt and dust to get into the gap from the cut surface.

[0006] In the container described in Patent Document 1, a frame member is attached to the cut surface of a plastic corrugated board sheet. The frame member fits over the cut surface to prevent voids from being exposed at the cut surface.

[0007] However, because rivets are required to secure the frame members, the number of parts increases accordingly, which in turn leads to problems such as increased costs and poor workability during assembly.

[0008] It should be noted that these problems are not limited to containers made of hollow plate materials, but are also common to containers made of solid plate materials to which frame members are attached for reinforcement or other purposes. [Means for solving the problem]

[0009] In order to solve the above problems, the present invention comprises a container body having a side wall portion and a bottom wall portion, a frame member attached along at least one of the upper and lower edges of the side wall portion, and a corner member fixed so as to straddle a pair of adjacent side wall portions at the edge to which the frame member is attached, and the corner member is integrally provided with a regulating portion that regulates the frame member from moving in the vertical direction relative to the corner member.

[0010] In the above configuration, it is preferable that the container body is formed of a hollow plate-like hollow structure, and a first surplus resin portion that fills the internal space of the hollow structure is integrally formed with the corner member.

[0011] In the above configuration, it is preferable that the restricting portion is provided closer to the edge than the frame member in the up-down direction of the corner member. In the above configuration, it is preferable that the frame member has a side wall extending along a main surface of the side wall portion, and the restricting portion is integrally formed with a resin reservoir abutting an outer surface of the side wall.

[0012] In the above configuration, it is preferable that a second surplus resin portion is integrally formed with the corner member and enters between the side wall portion and the frame member. Effect of the Invention

[0013] According to the present invention, the number of parts constituting the container can be reduced. [Brief description of the drawings]

[0014] [Figure 1] FIG. 1 is a perspective view of the container of this embodiment. [Diagram 2] FIG. 2 is a perspective view of a frame member. [Diagram 3] FIG. 3 is a diagram illustrating the corner member, and is a partial perspective view of the upper end portion of the container. [Figure 4] FIG. 4 is a diagram illustrating the restricting portion, and is a cross-sectional view taken along line 4-4 in FIG. [Diagram 5] FIG. 5 is a diagram illustrating the second surplus resin portion, and is a cross-sectional view taken along line 5-5 in FIG. [Figure 6] FIG. 6 is a diagram for explaining the bottom corner member, and is a partial perspective view of the lower end portion of the container. [Figure 7] 7(a) to 7(c) are diagrams illustrating the structure of the hollow structural body that constitutes the container body. [Figure 8] 8(a) to 8(c) are diagrams illustrating a method for manufacturing a hollow structural body. [Figure 9] FIG. 9 is a partial cross-sectional view of two upper and lower containers stacked one on top of the other. [Figure 10] FIG. 10 is a diagram illustrating a mold for injection molding the corner member. [Figure 11] 11(a) to 11(d) are diagrams illustrating a method of forming a corner member. [Figure 12] FIG. 12 is a partial cross-sectional view taken along line 12-12 in FIG. 11(d). [Figure 13] FIG. 13 is a diagram for explaining the state inside the mold during injection molding. [Figure 14] FIG. 14 is a diagram illustrating a modified example of the restricting portion. [Figure 15] FIG. 15 is a diagram illustrating a modified example of the restricting portion. [Figure 16]FIG. 16 is a diagram illustrating a modified example of the restricting portion. [Figure 17] FIG. 17 is a diagram illustrating a modified example of the restricting portion. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] Hereinafter, a container according to one embodiment of the present invention will be described. 1, the container 1 includes a container body 10, a frame member 20, a corner member 30, and a bottom corner member 40. In the following description, the side of the container 1 to which the corner member 30 is attached is referred to as the upper side, and the side to which the bottom corner member 40 is attached is referred to as the lower side.

[0016] The container body 10 is formed in a rectangular parallelepiped shape having four rectangular side walls 11 and a rectangular bottom wall 12 that closes the lower surface. An opening 13 that opens upward is formed in the upper part of the container 1. The frame members 20 are attached to the upper edges 14 of the four side walls 11. The corner members 30 are attached to the upper edges 14 of the side walls 11 at corners on the opening 13 side of the container body 10 so as to straddle adjacent side walls 11. The bottom corner members 40 are attached to the lower edges 15 of the side walls 11 and the bottom wall 12 at corners on the bottom wall 12 side of the container body 10 so as to straddle adjacent side walls 11 and bottom wall 12.

[0017] <About the container body 10> The container body 10 is formed by bending a hollow plate-like hollow structure 50 having a plurality of cells S formed therein.

[0018] First, the structure of the hollow structural body 50 will be described with reference to FIG. 7(a), a hollow structure 50 of this embodiment includes a core layer 51 having a plurality of cells S arranged side by side therein, a skin layer 52 joined to an upper surface 51a of the core layer 51, and a skin layer 53 joined to a lower surface 51b of the core layer 51. In the following description, the hollow structure 50 and the core layer 51 will be described with the side to which the skin layer 52 is joined as the upper side and the side to which the skin layer 53 is joined as the lower side.

[0019] As shown in Fig. 7(b) and (c), the core layer 51 is formed by folding a sheet material obtained by forming a thermoplastic resin sheet into a predetermined shape. The core layer 51 is composed of an upper wall portion 54, a lower wall portion 55, and a side wall portion 56 that is erected between the upper wall portion 54 and the lower wall portion 55 and forms a hexagonal cylindrical wall portion. The upper wall portion 54, the lower wall portion 55, and the side wall portion 56 define hexagonal columnar cells S inside the core layer 51. As described below, the upper wall portion 54 and the lower wall portion 55 of the core layer 51 have a structure in which a one-layer structure and a two-layer structure are mixed, but in Fig. 7(a), the upper wall portion 54 and the lower wall portion 55 of the core layer 51 are shown as a one-layer structure.

[0020] As shown in Figures 7(b) and (c), the cells S formed inside the core layer 51 include a first cell S1 and a second cell S2 having different structures. As shown in Figure 7(b), in the first cell S1, a two-layered upper wall portion 54 is provided on the upper part of the side wall portion 56. The layers of the two-layered upper wall portion 54 are bonded to each other. In addition, an opening (not shown) is formed in the two-layered upper wall portion 54 due to thermal contraction of the thermoplastic resin during molding of the core layer 51. In the first cell S1, a one-layered lower wall portion 55 is provided on the lower part of the side wall portion 56.

[0021] 7(c), in the second cell S2, a single-layered upper wall 54 is provided on the upper part of the side wall 56. In the second cell S2, a two-layered lower wall 55 is provided on the lower part of the side wall 56. The layers of the two-layered lower wall 55 are bonded to each other. An opening (not shown) is formed in the two-layered lower wall 55 due to thermal contraction of the thermoplastic resin when the core layer 51 is molded.

[0022] 7(b) and 7(c), adjacent first cells S1 and adjacent second cells S2 are partitioned by sidewalls 56 having a two-layer structure. The two-layer sidewalls 56 have portions that are not heat-welded to each other in the center in the thickness direction of the core layer 51. Therefore, the internal space of each cell S of the core layer 51 communicates with the internal spaces of the other cells S through the two-layer sidewalls 56.

[0023] As shown in Fig. 7(a), the first cells S1 are arranged in a row along the X direction. Similarly, the second cells S2 are arranged in a row along the X direction. The rows of the first cells S1 and the rows of the second cells S2 are alternately arranged in the Y direction perpendicular to the X direction. The first cells S1 and the second cells S2 form a honeycomb structure as a whole in the core layer 51.

[0024] The thermoplastic resin constituting the core layer 51 and the skin layers 52, 53 may be any conventionally known thermoplastic resin, such as polypropylene resin, polyamide resin, polyethylene resin, acrylonitrile-butadiene-styrene copolymer resin, acrylic resin, polybutylene terephthalate resin, etc. In this embodiment, the core layer 51 and the skin layers 52, 53 are made of polypropylene resin. The thermoplastic resin constituting the core layer 51 and the thermoplastic resin constituting the skin layers 52, 53 are preferably made of the same material. In this embodiment, the skin layers 52 and 53 have the same thickness.

[0025] Next, a method for manufacturing the hollow structural body 50 will be described. As shown in FIG. 8, the hollow structural body 50 is manufactured by forming a core layer 51 from one sheet material 100 and bonding skin layers 52 and 53 to the core layer 51.

[0026] As shown in FIG. 8(a), the sheet material 100 is formed by molding one thermoplastic resin sheet into a predetermined shape. The sheet material 100 has band-shaped planar regions 110 and bulging regions 120 arranged alternately in the longitudinal direction (X direction) of the sheet material 100. In the bulging region 120, a first bulging portion 121 having a cross section of a downward groove shape consisting of an upper surface and a pair of side surfaces is formed over the entire extending direction (Y direction) of the bulging region 120. Note that the angle between the upper surface and the side surface of the first bulging portion 121 is preferably 90 degrees, and as a result, the cross section of the first bulging portion 121 has a downward U-shape. The width of the first bulging portion 121 (the length of the short side of the upper surface) is set to be equal to the width of the planar region 110 and twice the length of the bulging height of the first bulging portion 121 (the length of the short side of the side surface).

[0027] In addition, in the bulging region 120, a plurality of second bulging portions 122, each of which has a cross-sectional shape that is a trapezoid obtained by bisecting a regular hexagon at its longest diagonal, are formed so as to be perpendicular to the first bulging portion 121. The bulging height of the second bulging portion 122 is set to be equal to the bulging height of the first bulging portion 121. In addition, the interval between adjacent second bulging portions 122 is equal to the width of the upper surface of the second bulging portion 122.

[0028] The first bulging portion 121 and the second bulging portion 122 are formed by partially bulging the sheet upwards by utilizing the plasticity of the sheet. The sheet material 100 can be formed from a single sheet by a known forming method such as vacuum forming or compression forming.

[0029] As shown in Figs. 8(a) and (b), the sheet material 100 configured as described above is folded along the boundary lines P and Q to form the core layer 51. Specifically, the sheet material 100 is valley-folded at the boundary line P between the flat region 110 and the bulging region 120, and mountain-folded at the boundary line Q between the top surface and side surface of the first bulging portion 121 to compress in the X direction. Then, as shown in Figs. 8(b) and (c), the top surface and side surface of the first bulging portion 121 are folded over, and the end surface of the second bulging portion 122 and the flat region 110 are folded over, thereby forming one rectangular column-shaped partition 130 extending in the Y direction for one bulging region 120. Such partitions 130 are continuously formed in the X direction to form the hollow plate-shaped core layer 51.

[0030] When the sheet material 100 is compressed as described above, the upper surface and side surface of the first bulge portion 121 form the upper wall portion 54 of the core layer 51, and the end surface of the second bulge portion 122 and the flat region 110 form the lower wall portion 55 of the core layer 51. As shown in Fig. 8(c), the portion of the upper wall portion 54 where the upper surface and side surface of the first bulge portion 121 are folded over to form a two-layer structure, and the portion of the lower wall portion 55 where the end surface of the second bulge portion 122 and the flat region 110 are folded over to form a two-layer structure respectively become overlapping portions 131.

[0031] Moreover, a hexagonal columnar region formed by folding the second bulging portion 122 becomes the second cell S2, and a hexagonal columnar region formed between a pair of adjacent partitions 130 becomes the first cell S1. In this embodiment, the upper surface and side surface of the second bulging portion 122 form the side wall portion 56 of the second cell S2, and the side surface of the second bulging portion 122 and a flat portion located between the second bulging portions 122 in the bulging region 120 form the side wall portion 56 of the first cell S1. The contact portion between the upper surfaces of the second bulging portions 122 and the contact portion between the flat portions in the bulging region 120 form the side wall portion 56 having a two-layer structure. Note that, when carrying out such a folding process, it is preferable to heat-treat the sheet material 100 so as to soften it.

[0032] Next, the skin layer 52 is superimposed on the upper surface of the core layer 51, and the skin layer 53 is superimposed on the lower surface of the core layer 51. The skin layers 52 and 53 are preferably softened by heat treatment. By heat treating the skin layers 52 and 53, the adhesive layer of thermoplastic resin coated on the skin layers 52 and 53 is partially thermally melted. Therefore, the skin layers 52 and 53 superimposed on the core layer 51 are positioned in a state where they are temporarily bonded to the core layer 51. The adhesive layer solidifies due to a decrease in temperature of the core layer 51 and the skin layers 52 and 53, and the skin layers 52 and 53 are bonded to the core layer 51 to form the hollow structure 50.

[0033] <Regarding the frame member 20> As shown in FIG. 1, the frame member 20 is an elongated member attached to each of the upper edges 14 of the four side wall portions 11 of the container body 10.

[0034] 2, the frame member 20 is formed in a U-shaped cross section having a pair of side walls 21 and a connecting wall 22 connecting the pair of side walls 21. An internal space 23 of the frame member 20 serves as an accommodation space for accommodating an end portion of the side wall portion 11 on the upper edge 14 side.

[0035] The side walls 21 and the connecting walls 22 have approximately the same thickness. The frame member 20 has an approximately uniform thickness over its entirety. 2, recesses 24 are formed at both ends of the side wall 21 in the longitudinal direction by cutting out the longitudinal end edges 21c. The recesses 24 penetrate the inner surface 21a and the outer surface 21b of the side wall 21. The recesses 24 are formed in the center of the side wall 21 in the up-down direction.

[0036] The recess 24 in this embodiment has a circular arc portion 25 and a shaft portion 26 that connects the arc portion 25 to the end edge 21c. The arc portion 25 is formed so that its diameter is larger than the length of the shaft portion 26 in the vertical direction.

[0037] <Regarding the corner member 30> 1, the corner member 30 is attached to the upper edge 14 of the side wall portion 11 at a corner portion on the opening 13 side of the container body 10 so as to straddle the adjacent side wall portions 11. Therefore, the corner member 30 is formed in an L-shape in top view that is approximately linearly symmetrical with respect to the dotted line shown in FIG.

[0038] 3 and 4, the corner member 30 includes a corner main body portion 31, a restricting portion 36, a first surplus resin portion 37, a second surplus resin portion 38, and a resin reservoir 39. The corner main body portion 31, the restricting portion 36, the first surplus resin portion 37, the second surplus resin portion 38, and the resin reservoir 39 are formed as an integrally molded product. The corner member 30 is integrally molded by injection molding in a manufacturing method for the container 1 described later.

[0039] 3, the corner main body portion 31 includes an inner wall 32, an outer wall 33, a connecting wall 34 connecting the inner wall 32 and the outer wall 33, and an abutment wall 35 protruding horizontally from the connecting wall 34 and extending vertically. The space surrounded by the inner wall 32, the outer wall 33, and the connecting wall 34 becomes an accommodation space that accommodates the end portion of the side wall portion 11 of the container body 10 on the side of the upper edge 14.

[0040] 4, the outer surface 32b of the inner wall 32 is substantially flush with the outer surface 21b of the inner side wall 21 of the frame member 20. The outer surface 33b of the outer wall 33 is substantially flush with the outer surface 21b of the outer side wall 21 of the frame member 20. The edge 32c of the inner wall 32 and the edge 33c of the outer wall 33 are butted against the edge 21c of the side wall 21 of the frame member 20 with almost no gap.

[0041] 3, the outer surface 34b of the connecting wall 34 is substantially flush with the outer surface 22b of the connecting wall 22 of the frame member 20. The abutment wall 35 is formed so that its inner surface 35a is positioned slightly outward from the outer surface 33b of the outer wall 33 (see FIG. 5).

[0042] 3 and 4, the restricting portion 36 is formed so as to extend from an edge 32c of the inner wall 32 and an edge 33c of the outer wall 33. The restricting portion 36 is filled inside the recess 24 of the frame member 20. The restricting portion 36 has an arc portion 36a that fills the arc portion 25 of the recess 24 and an axis portion 36b that fills the axis portion 26. The restricting portion 36 extends along the main surface 11a of the side wall portion 11 of the container body 10 with its inner surface 36c abutting against the main surface 11a.

[0043] As shown in Figs. 4 and 5, the second surplus resin portion 38 is formed integrally with the corner main body portion 31 so as to extend from the corner main body portion 31. Specifically, it is formed so as to extend from the edge 32c of the inner wall 32, the edge 33c of the outer wall 33, and the edge (not shown) of the connecting wall 34 of the corner main body portion 31. As shown in Fig. 5, the second surplus resin portion 38 is inserted between the inner surface of the frame member 20 and the outer surface of the side wall portion 11 of the container body 10, and is in a state of spreading along the main surface 11a of the side wall portion 11. The second surplus resin portion 38 abuts against the inner surface 21a of the frame member 20 and the main surface 11a of the side wall portion 11 of the container body 10.

[0044] 5, the resin hatch lines of the second surplus resin portion 38 formed integrally with the corner main body portion 31 (connecting wall 34) are omitted in order to easily show the state in which the second surplus resin portion 38 spreads along the main surface 11a of the side wall portion 11.

[0045] As shown in Figs. 4 and 5, the first surplus resin portion 37 is formed integrally with the inner wall 32, the outer wall 33, and the connecting wall 34 of the corner body portion 31, and the second surplus resin portion 38 extending from the corner body portion 31. The first surplus resin portion 37 is formed so as to fill the internal space of the cell S of the hollow structure 50 constituting the side wall portion 11 of the container body 10. This is because, when the corner member 30 is injection molded in the first molding step described later, the high-temperature molten resin and its injection pressure cause the molten resin to flow so as to break through the side wall portion 56 of the core layer 51 of the hollow structure 50, and the molten resin enters the cell S. The first surplus resin portion 37 formed integrally with the corner body portion 31 enters the internal space of the cell S, so that the corner member 30 is firmly fixed to the side wall portion 11 of the container body 10 in a non-dislodging state.

[0046] 3 and 4, the resin reservoir 39 is formed on the outer surface 21b side of the side wall 21 of the frame member 20 at the position of the arc portion 36a of the restricting portion 36. In the container 1 of this embodiment, when the frame member 20 is attached to the container body 10, the resin reservoir 39 is formed on the outer surface 21b side of the side wall 21 located on the outside.

[0047] 3, the resin reservoir 39 is formed in a square shape when viewed from the front. The length of the side of the resin reservoir 39 is longer than the diameter of the arc portion 36a of the restricting portion 36 and longer than the diameter of the arc portion 25 of the recess 24 of the side wall 21 of the frame member 20. Therefore, the resin reservoir 39 prevents the side wall 21 of the frame member 20 from moving in a direction away from the side wall portion 11 of the container body 10.

[0048] <About the bottom corner member 40> 6, the bottom corner member 40 is attached to the lower edge 15 of the side wall portion 11 and the bottom wall portion 12 at a corner portion on the bottom wall portion 12 side of the container body 10 so as to straddle the adjacent side wall portions 11 and bottom wall portions 12. The bottom corner member 40 is integrally molded by injection molding in the second molding step in the manufacturing method of the container 1, which will be described later.

[0049] 1 and 6, the bottom corner member 40 is provided on both the outer surface side and the inner surface side of the container body 10. Since it is integrally molded by injection molding, it has a similar structure to the first excess resin portion 37 of the corner member 30 (not shown). As a result, the bottom corner member 40 is firmly fixed to the side wall portion 11 and the bottom wall portion 12 of the container body 10 in a non-dislodging state.

[0050] 6, the outer surface side of the bottom corner member 40 has a pair of side walls 41 and a bottom wall 42. The side walls 41 and the bottom wall 42 are triangular plate-shaped. A leg portion 43 extending along the extension direction of the side wall 41 is formed on the outer surface (bottom surface) of the bottom wall 42.

[0051] As shown in FIG. 9, the distance between the outer edge of the leg 43 of the bottom corner member 40 and the outer surface of the side wall 41 is slightly smaller than the distance between the outer surface 32b of the inner wall 32 of the corner member 30 and the inner surface 35a of the abutment wall 35. Therefore, when multiple containers 1 are stacked, the bottom wall 42 of the bottom corner member 40 of the upper container 1 is placed on the connecting wall 34 of the corner member 30 of the lower container 1. At this time, the side wall 41 of the bottom corner member 40 of the upper container 1 abuts or nearly abuts the abutment wall 35 of the corner member 30 of the lower container 1. In addition, the leg 43 of the bottom corner member 40 of the upper container 1 enters the inner surface of the inner wall 32 of the corner member 30 of the lower container 1. The abutment wall 35 of the corner member 30 and the leg 43 of the bottom corner member 40 stabilize the stacked state.

[0052] <About the manufacturing method of container 1> Next, a method for manufacturing the container 1 will be described together with the function of the container 1. The manufacturing method of the container 1 includes a container body forming step of forming the container body 10, an attachment step of attaching the frame member 20, a first molding step of injection molding the corner member 30, and a second molding step of injection molding the bottom corner member 40. The following description will focus on the first molding step.

[0053] In the container body forming process, the container body 10 is formed by bending the hollow structure 50 cut into a predetermined shape. For example, the container body 10 is cut into an unfolded shape in which the four side walls 11 are connected to the four sides of the bottom wall 12. The four side walls 11 in the unfolded shape have excess portions that serve as glue margins at positions that correspond to the sides of the side walls 11 extending in the up-down direction in the container body 10. The hollow structure 50 cut into the unfolded shape is heat bent at the boundaries between the four side walls 11 and the bottom wall 12, and the heat-compressed excess portions are heat welded to the sides of the adjacent side walls 11.

[0054] In the attachment process, frame members 20 are attached to each of the upper edges 14 of the side wall portions 11 of the container body 10. The length of the frame members 20 is about 5 mm shorter than the upper edges 14 of the side wall portions 11. The frame members 20 are attached to the upper edges 14 at positions offset by the same length from both side edges of the side wall portions 11. In other words, with the frame members 20 attached, areas of the upper edges 14 of the side wall portions 11 where the frame members 20 are not attached are formed at both end edges of the same length.

[0055] In the first molding step, a mold for injection molding is attached to the container 1 at a position where the corner member 30 is to be provided, and injection molding is performed. 10, the mold is composed of an inner mold 61 and an outer mold 62. The inner mold 61 has a recess 63 formed therein to form cavities for molding the inner wall 32, the outer wall 33, and the connecting wall 34. Also, a protrusion 64 formed therein to form a cavity for molding the contact wall 35 is formed.

[0056] The outer mold 62 is formed with a recess 65 that forms a cavity for molding the inner wall 32, the outer wall 33, and the connecting wall 34. Also, a recess 66 that forms a cavity for molding the abutment wall 35 is formed. Furthermore, the recess 65 is formed with a recess 67 that forms the resin reservoir 39. And, the recess 66 is formed with a resin gate 68 that supplies resin into the cavity.

[0057] As shown in Fig. 11(a), in the first molding step, first, an inner mold 61 and an outer mold 62 are prepared. Then, as shown in Fig. 11(b), the container body 10 to which the frame member 20 is attached is set in the outer mold 62. At this time, the frame member 20 is aligned so as to be fitted into the recess 65 of the outer mold 62. After alignment, the inner mold 61 is clamped.

[0058] In the clamped state, in the region where the frame member 20 is attached between the recess 63 of the inner mold 61 and the recess 65 of the outer mold 62, there is almost no gap between the frame member 20 and the inner surfaces of the recess 63 and the recess 65. In the region of the container body 10 where the frame member 20 is not attached, cavities for molding the inner wall 32, the outer wall 33, and the connecting wall 34 of the corner member 30 are formed between the recess 63 and the recess 65. In addition, a cavity for molding the abutment wall 35 of the corner member 30 is formed between the protrusion 64 and the recess 66.

[0059] 11(c) and 12, molten polypropylene resin that has been heated and turned to a molten state is supplied from the resin gate 68 of the clamped outer mold 62. The amount of polypropylene resin supplied is set to be slightly larger than the volume of the cavity.

[0060] The molten resin supplied from the resin gate 68 is supplied into the recesses 63 and 65, and fills the area where the frame member 20 is not attached. On the other hand, in the area where the frame member 20 is attached, there is almost no gap between the frame member 20 and the inner surfaces of the recesses 63 and 65. Therefore, the flow of the molten resin stops at the position of the edge 21c of the side wall 21 of the frame member 20 and the position of the edge 22c of the connecting wall 22.

[0061] On the other hand, the recess 24 formed in the frame member 20 is formed in a shape cut out from the edge 21c of the frame member 20, so that the molten resin from the cavity is supplied to the recess 24 of the frame member 20. Also, since the outer die 62 has a recess 67 for forming the resin reservoir 39 of the corner member 30, the molten resin supplied to the recess 24 of the frame member 20 is supplied to the recess 67.

[0062] The amount of molten resin is set to be slightly larger than the volume of the cavity, so that the supply pressure causes the molten resin to enter the gap between the inner surface 21a of the side wall 21 of the frame member 20 and the inner surface of the connecting wall 22 (see FIG. 5). The molten resin also breaks through the skin layer 52 and upper wall portion 54 of the core layer 51, the skin layer 53 and lower wall portion 55 of the core layer 51, and the side wall portion 56 of the hollow structure 50, and enters the internal space of the cell S.

[0063] 11(d), the mold is cooled after molten resin is supplied from resin gate 68. When the mold is opened after cooling, corner member 30 is attached to the upper end of side wall portion 11.

[0064] 13 is a diagram showing the internal state of the mold, with the inner mold 61 and one of the frame members 20 omitted. By injection molding the corner member 30, the corner member 30 is formed without any gaps up to the positions of the edge 21c of the side wall 21 of the frame member 20 and the edge 22c of the connecting wall 22. In addition, the molten resin enters the recess 24 of the frame member 20, thereby forming a restricting portion 36 in the corner member 30. Since the recess 24 is formed in the central portion of the frame member 20 in the up-down direction, the side wall 21 of the frame member 20 exists below the restricting portion 36.

[0065] The molten resin that has entered the gap between the inner surface 21a of the side wall 21 of the frame member 20 and the inner surface of the connecting wall 22 becomes the second surplus resin portion 38, and the molten resin that has entered the internal space of the cell S becomes the first surplus resin portion 37 (see Figure 4).

[0066] Next, in the second molding step, a mold for injection molding is attached to the container 1 at a position where the bottom corner member 40 is to be provided, and injection molding is performed. Through the above steps, the container 1 can be manufactured.

[0067] In the injection-molded corner member 30, the side wall 21 of the frame member 20 exists below the restricting portion 36. In other words, in the vertical direction of the corner member 30, the restricting portion 36 is provided closer to the upper edge 14 of the side wall portion 11 of the container body 10 than the frame member 20. Therefore, the upward movement of the frame member 20 is restricted by the restricting portion 36 of the corner member 30 fixed to the container body 10. The restricting portion 36 formed on the corner member 30 has the effect of restricting the movement of the frame member 20 in the vertical direction.

[0068] Furthermore, the resin reservoir 39 formed in the recess 67 of the outer mold 62 presses the frame member 20 from the outer surface 21b of the side wall 21 of the frame member 20. Therefore, the movement of the frame member 20 is further restricted.

[0069] Furthermore, the first surplus resin portion 37 that has entered the cell S exerts an anchor effect, and the corner member 30 is firmly fixed to the container body 10. As a result, the frame member 20 is also more firmly fixed to the container body 10.

[0070] According to the container 1 and the manufacturing method thereof of this embodiment, the following effects can be obtained. (1) The container 1 comprises a container body 10 having a side wall portion 11 and a bottom wall portion 12, a frame member 20 attached along an upper edge 14 of the side wall portion 11, and a corner member 30 fixed so as to straddle a pair of adjacent side wall portions 11 at the upper edge 14 to which the frame member 20 is attached. The corner member 30 is integrally provided with a restricting portion 36 that restricts the relative movement of the frame member 20 in the up-down direction.

[0071] Therefore, there is no need for fixing members such as rivets for fixing the frame member 20. This reduces the number of parts, reduces costs, and improves workability during assembly. Recyclability is also improved.

[0072] (2) The container body 10 is formed of a hollow plate-like hollow structure 50. The corner member 30 is integrally formed with a first excess resin portion 37 that enters the internal space of the side wall portion 11 of the container body 10.

[0073] Therefore, the corner member 30 is firmly fixed to the container body 10. Fixing members such as rivets for fixing the corner member 30 are not required. The number of parts can be further reduced, which leads to cost reduction and improved workability during assembly. Recyclability is also improved.

[0074] (3) The recess 24 of the frame member 20 in which the restricting portion 36 is provided is formed in the vertical center portion of the frame member 20. In other words, the restricting portion 36 is provided on the upper edge 14 side of the frame member 20 in the vertical direction of the corner member 30.

[0075] Therefore, the upward movement of the frame member 20 can be restricted by the restricting portion 36 of the corner member 30 fixed to the container body 10. The movement of the frame member 20 can be restricted with a simple structure.

[0076] (4) The frame member 20 has a side wall 21 extending along the main surface 11a of the side wall portion 11 of the container body 10. The restricting portion 36 has a resin reservoir 39 that abuts against the outer surface 21b of the side wall 21 formed integrally therewith.

[0077] Therefore, the outer surface 21b of the side wall 21 of the frame member 20 is held down by the resin pool 39. This makes it possible to prevent the side wall 21 of the frame member 20 from peeling off from the side wall portion 11 of the container body 10. The movement of the frame member 20 is more firmly restricted.

[0078] (5) The corner member 30 has the second excess resin portion 38 formed integrally therewith and inserted between the side wall portion 11 of the container body 10 and the frame member 20 . Therefore, the frame member 20 is fixed to the side wall portion 11 by the second surplus resin portion 38. The movement of the frame member 20 is more firmly restricted. Also, the gap between the frame member 20 and the container body 10 is filled. The rattling of the frame member 20 is suppressed, and the mounting state is stabilized.

[0079] (6) The corner member 30 is formed by injection molding, and a molten resin slightly larger than the volume of the cavity is supplied. Therefore, it is possible to minimize the gap between the frame member 20 and the corner member 30. Also, the corner member 30 can be formed without a gap even if the dimensions of the frame member 20 are not strictly determined. Also, even if there is a dimensional difference in the frame member 20, the corner member 30 can be injection molded to match the dimensions of the frame member 20.

[0080] The above embodiment can be modified as follows: The above embodiment and the following modified examples can be applied in combination with each other to the extent that there is no technical contradiction. The frame member 20 and the corner member 30 are attached to the upper edge 14 of the side wall portion 11 of the container body 10, but are not limited to this. They may be attached to the lower edge 15. In this case, it is considered that the lower edge 15 of the side wall portion 11 may have a shape that protrudes downward from the lower surface of the bottom wall portion 12.

[0081] The shape of the restricting portion 36 is not limited to that in the above embodiment. 14, the side wall 21 of the frame member 20 is longer in the downward direction, and the inner wall 32 and the outer wall 33 of the corner main body portion 31 of the corner member 30 are shorter in the downward direction. In this case, the horizontal end portion of the corner member 30 becomes the restricting portion 36d. The restricting portion 36d is provided closer to the upper edge 14 of the side wall portion 11 than the frame member 20 in the vertical direction of the corner member 30, and the movement of the frame member 20 in the vertical direction is restricted.

[0082] 15, the lower portion of the longitudinal end of the frame member 20 may protrude in the longitudinal direction, and the inner wall 32 and the outer wall 33 of the corner main body portion 31 of the corner member 30 may protrude at the upper portion of the horizontal end. In this case as well, the protruding portion of the corner member 30 serves as the restricting portion 36e.

[0083] The restricting portion 36 does not have to be formed of the arc portion 36a and the shaft portion 36b. Like the restricting portion 36f shown in Fig. 16, the shaft portion 36b does not have to be provided. The restricting portion 36f may be semicircular.

[0084] As shown in FIG. 17, the restriction portion 36g may be a straight cutout. The bottom corner member 40 may be omitted. The legs 43 of the bottom corner member 40 may be omitted.

[0085] The bottom corner member 40 in the above embodiment is attached to the lower edge 15 of the side wall portion 11 and the bottom wall portion 12 so as to straddle the adjacent side wall portions 11 and bottom wall portions 12, but is not limited to this. The bottom corner member 40 may be provided only on the bottom wall portion 12, rather than straddling the side wall portions 11. In this case, if legs 43 are formed on the bottom wall 42, the legs 43 of an upper container 1 can be fitted into the corner member 30 of a lower container 1 when multiple containers 1 are stacked.

[0086] The core layer 51 does not have to be formed through a folding process in which the embossed sheet material 100 is folded. The hollow structure 50 can be made of any hollow plate material known in the art.

[0087] Prior to the first molding step, holes may be formed in the hollow structure 50 at the portion where the corner member 30 is to be injection molded. In this case, the molten resin fills the hole during injection molding, and the molten resin acts as an anchor. This anchor effect makes it possible to attach the corner member more firmly.

[0088] Although the container body 10 is formed of the hollow structure 50, it does not have to be such a hollow plate material. It may be formed of a solid plate material that does not have a hollow space formed inside. In the manufacturing method of the container 1 of the above embodiment, in the container body forming step, the hollow structure 50 cut into an unfolded shape is folded to form the container body 10. In the portion that will become the side edge extending in the vertical direction of the side wall portion 11, the excess portion is crushed, bent, and heat-sealed, so that the internal space of the cells S of the core layer 51 is sealed by the excess portion. On the other hand, in the portion that will become the upper edge 14 of the container body 10, the internal space of the cells S of the core layer 51 is exposed. In order to prevent the core layer 51 from being exposed in this portion, for example, an end face sealing process may be performed when the container body 10 is cut into an unfolded shape. The end face sealing process can be performed, for example, by attaching a thin sheet to the portion that will become the upper edge 14.

[0089] In the hollow structure 50 of the above embodiment, the cells S having a hexagonal columnar shape are defined and formed inside the core layer 51, but the shape of the cells S is not limited to this. For example, the cells S may have a polygonal columnar shape such as a square columnar shape or an octagonal columnar shape, or a cylindrical shape.

[0090] At least one of the skin layers 52, 53 joined to the hollow structure 50 may have a multi-layer structure instead of a single layer structure. For example, it may have a multi-layer structure including a low melting point film layer, a decorative layer with a printed pattern, a nonwoven fabric layer, etc.

[0091] The skin layers 52, 53 may be made of a metal surface material. At least one of the skin layers 52, 53 may be omitted. The thermoplastic resin constituting the core layer 51 and the skin layers 52 and 53 may contain various functional resins. For example, flame retardancy can be improved by adding a flame retardant resin to the thermoplastic resin. It is also possible to use thermoplastic resins containing various functional resins for all of the core layer 51 and the skin layers 52 and 53, or to use a functional resin for at least one of the core layer 51 and the skin layers 52 and 53.

[0092] In the above embodiment, the hollow structural body 50 and the corner member 30 are made of polypropylene resin. The material is not limited to this. They may be the same resin material or different resin materials. It is preferable that the hollow structural body 50, the frame member 20, the corner member 30, and the bottom corner member 40 are made of the same material.

[0093] The material of each member can be appropriately selected. For example, the hollow structural body 50, the corner members 30, and the bottom corner members 40 may be made of a resin material, and the frame member 20 may be made of a metal material.

[0094] Technical matters that can be understood from the above embodiment and each modified example will be described below. (i) A container comprising a container body having side wall portions and a bottom wall portion, a frame member attached along at least one of the upper and lower edges of the side wall portions, and a corner member fixed so as to straddle a pair of adjacent side wall portions at the edge to which the frame member is attached, wherein the corner member is integrally provided with a regulating portion for regulating the relative movement of the frame member in the vertical direction.

[0095] (b) The container described in (a) above, characterized in that the container body is formed of a hollow plate-like hollow structure, and the corner member is integrally formed with a first excess resin portion that penetrates into the internal space of the hollow structure.

[0096] (C) The container according to (A) or (B) above, wherein the regulating portion is provided on the edge side of the corner member in the up-down direction of the corner member relative to the frame member. (ii) A container described in any one of (i) to (iii) above, characterized in that the frame member has a side wall extending along a main surface of the side wall portion, and the regulating portion has a resin reservoir integrally formed therewith that abuts against an outer surface of the side wall.

[0097] (e) A container described in any one of (a) to (d) above, characterized in that a second excess resin portion is integrally formed with the corner member and is inserted between the side wall portion and the frame member. [Explanation of symbols]

[0098] 10...Container body 11...Side wall 12...Bottom wall 14…Top edge 15…Lower edge 20...Frame member 30…Corner parts 36…Regulation Department 37…First excess resin part 38…Second excess resin part 50...Hollow structure

Claims

1. A container body having a side wall portion and a bottom wall portion; a frame member attached along at least one of an upper end edge and a lower end edge of the side wall portion; a corner member fixed to the edge where the frame member is attached so as to straddle a pair of adjacent side wall portions; Equipped with A container according to claim 1, wherein the corner member is integrally provided with a restricting portion for restricting the frame member from moving up and down relative to the corner member.

2. The container body is formed of a hollow plate-like hollow structure, 2. The container according to claim 1, wherein a first excess resin portion that fills the internal space of the hollow structure is integrally formed with the corner member.

3. 2. The container according to claim 1, wherein the restricting portion is provided on the edge side of the corner member relative to the frame member in the up-down direction.

4. The frame member includes a side wall extending along a main surface of the side wall portion, 2. The container according to claim 1, wherein the restricting portion is integrally formed with a resin reservoir that abuts against an outer surface of the side wall.

5. 3. The container according to claim 2, wherein a second excess resin portion is integrally formed with the corner member and is disposed between the side wall portion and the frame member.

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