Packaging box

Abstract

To provide a packaging box whose top part can be easily and reliably assembled.SOLUTION: A top part 20 of a packaging box 1 has front and rear end flaps 50 and 50 and left and right side flaps 60 and 60, with a central opening 62 formed between the side flaps 60 and 60. The end flap 50 has a base end part 51 overlapping the upper surfaces of the side flaps 60 and 60, and a folded-back part 53 inserted into a trunk pat 10 through the central opening 62 and folded back around the base end part 51. The folded part 53 has a tip end part 54 connected to the base end part 51, and left and right protrusion parts 55 and 55 connected to the left and right edge parts of the tip end part 54 and extending outward in the left-right direction beyond the central opening 62. The protrusion part 55 is connected to the tip end part 54 via a cut line.SELECTED DRAWING: Figure 1

Description

[Technical field]

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

[0002] An example of a cardboard packaging box is one that has a rectangular cylindrical body, a bottom that closes the lower opening of the body, and a top that is formed at the upper opening of the body, with a central opening formed in the center of the top. The top of the above-mentioned packaging box has an end flap connected to the upper edge of the body, and this end flap has a folded portion that is inserted into the body through a central opening and folded back toward the base end (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 4024183 Summary of the Invention [Problem to be solved by the invention]

[0004] The folded portion of the conventional packaging box described above has a tip portion connected to the base end portion, and left and right protrusion portions connected to the left and right edges of the tip portion, respectively, and the protrusion portions extend outward in the left-right direction beyond the central opening. In the above-mentioned conventional packaging box, the fold line between the tip of the folded-back portion and the protruding portion is a crease formed when the blank sheet is manufactured, and is formed on the same surface as the other fold lines.

[0005] When assembling the top of the conventional packaging box described above, before passing the folded portion through the central opening, both protruding portions can be folded in a mountain fold when viewed from above relative to the tip portions at the fold line to narrow the width of the folded portion. In the conventional packaging boxes described above, both protruding portions are manually folded toward the tip, and then the folded portion is passed through the central opening while keeping the width of the folded portion narrowed by hand, which creates a problem in that the assembly work at the top is cumbersome.

[0006] SUMMARY OF THE PRESENT EMBODIMENT An object of the present invention is to solve the above-mentioned problems and to provide a packaging box whose top can be easily and reliably assembled. [Means for solving the problem]

[0007] In order to solve the above problem, the present invention provides a packaging box, comprising a cylindrical body having front and rear end walls and left and right side walls, a bottom closing the lower opening of the body, and a top formed at the upper opening of the body. The top has front and rear end flaps connected to the upper edges of the front and rear end walls, and left and right side flaps connected to the upper edges of the left and right side walls, and a central opening is formed between the both side flaps. The end flaps have a base end overlapped on the upper surface of the both side flaps, and a folded back portion inserted into the body through the central opening and folded back against the base end. The folded back portion has a tip end connected to the base end, and a protruding portion connected to at least one of the left and right edges of the tip end and extending outward in the left and right direction from the central opening. The protruding portion is connected to the tip end via a cut line. The cut line is a cut formed on a virtual line indicating the boundary between the tip portion and the protruding portion, and the number of cuts is not limited; multiple cuts may be formed intermittently, or the cut line may be formed by a single cut.

[0008] In the packaging box of the present invention, the base ends of the end flaps and the folded-back portions sandwich the side flaps. Also, in the packaging box of the present invention, the protruding portions of the folded-back portions extend outward in the left-right direction beyond the central opening, making it difficult for the folded-back portions to slip out of the central opening. Therefore, in the packaging box of the present invention, the end flaps at the top and the side flaps can be reliably connected.

[0009] When assembling the top of the packaging box of the present invention, the end flaps are folded against the end walls, and the base ends are placed on the upper surfaces of the side flaps. Then, the tips of the folded-back portions are pushed into the central opening, and the protruding portions are pressed against the upper surfaces of the side flaps, forming a valley fold relative to the tips when viewed from above. In this way, when the tips of the folded-back portions are pushed into the central opening, the width of the folded-back portions narrows, and the folded-back portions pass through the central opening. The folded portion is then inserted into the body through the central opening, and folded back onto the base end portion, while the protruding portion opens left and right to increase the width of the folded portion, thereby connecting the end flaps to the side flaps. Therefore, in the packaging box of the present invention, the folded-back portion, which is wider than the central opening, can be easily passed through the central opening to assemble the top.

[0010] The folding (folding direction) of the creases (pressed creases) on the sheet has a directional characteristic depending on the surface on which the creases are made, and the sheet is likely to bend in a valley fold when viewed from the surface on which the creases are made (the processing direction). The corners of the packaging box are all mountain folds when viewed from the outside, so all the creases are made on one side of the sheet (the side that becomes the inner surface of the packaging box). In contrast, in the packaging box of the present invention, when assembling the top, the overhanging portion is folded in a valley shape relative to the tip as viewed from the outside. In other words, the overhanging portion is folded in a direction opposite to the way the corners of the packaging box are folded in a valley shape relative to the tip at the crease. If the overhanging portion is to be folded in a valley shape relative to the tip as viewed from the outside at the crease, it is necessary to process the crease on the other side of the sheet (the side that will become the outer surface of the packaging box), and since the crease is to be processed on both sides of the sheet, the manufacturing efficiency of the blank sheet is reduced. On the other hand, the cut line between the tip and the overhang in the present invention is easier to fold than the crease and has no directional tendency, so the overhang can be easily folded in a valley shape when viewed from the outside relative to the tip. The cut line can be cut from the same side of the sheet as the crease that will become the fold line, at the same time as the fold line is being processed. This makes it unnecessary to turn the sheet over for the processing machine, and allows the blank sheet to be manufactured efficiently.

[0011] In the packaging box described above, it is preferable that the cut line be formed along a line formed on the inner surface of the folded-back portion, so that the protruding portion can be easily folded in a valley fold relative to the tip portion when viewed from the outside.

[0012] In the above-mentioned packaging box, it is preferable that the left and right protruding portions of the folded portion are connected to the left and right edge portions of the tip portion via the cut line, respectively. In this configuration, since both protruding portions of the folded portion extend to both the left and right sides of the central opening, the folded portion is less likely to slip out of the central opening. Even if the folded portion has left and right protruding portions, the folded portion can be easily inserted into the central opening by pushing the tip of the folded portion into the central opening.

[0013] In the above-mentioned packaging box, it is preferable that an engagement recess is formed on the front-to-rear edge of the central opening, and the left-to-right width of the intermediate portion between the base end and the tip end is made the same as or larger than the left-to-right width of the engagement recess. When the intermediate portion is fitted into the locking recess, the intermediate portion can be held in the locking recess, thereby preventing the tip portion from reverting back to a flat state relative to the base portion and allowing the shape of the top portion to be maintained even when the body is empty. Effect of the Invention

[0014] In the packaging box of the present invention, the folded portion, which is wider than the central opening, can be passed through the central opening by pushing the tip of the folded portion into the central opening, making it possible to assemble the top easily and reliably. [Brief description of the drawings]

[0015] [Figure 1] 1 is a perspective view of a packaging box according to an embodiment of the present invention, viewed from the upper left front side. [Diagram 2] FIG. 2 is a diagram showing a blank sheet for a packaging box according to an embodiment of the present invention. [Diagram 3]1 is a side cross-sectional view showing a packaging box according to an embodiment of the present invention. [Figure 4] FIG. 13 is a perspective view showing a procedure for assembling the packaging box according to the embodiment of the present invention, showing the stage when the side flaps are folded. [Diagram 5] FIG. 13 is a perspective view showing the assembly procedure of the packaging box according to the embodiment of the present invention, showing the stage when the end flaps are folded. [Figure 6] FIG. 13 is a perspective view showing a procedure for assembling the packaging box according to the embodiment of the present invention, illustrating the stage in which the folded-back portion is folded back onto the base end portion. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail with reference to the accompanying drawings. In the following description, the front, rear, left and right directions are set for the sake of convenience in describing the packaging box of this embodiment, and do not limit the configuration or usage state of the packaging box.

[0017] 1, the packaging box 1 of this embodiment includes a body 10 formed in a rectangular cylindrical shape, a bottom 30 closing the lower opening of the body 10, and a top 20 formed at the upper opening of the body 10. Although the contents that can be stored in the packaging box 1 of this embodiment are not limited, in this embodiment, a packaging box 1 for storing multiple green onions will be described.

[0018] The packaging box 1 of this embodiment is formed by mountain-folding a blank sheet S cut out from a cardboard sheet along each fold line, as shown in Fig. 2. The blank sheet S shown in Fig. 2 is arranged so that the inner side is visible. The fold lines of the blank sheet S are creases (pressed creases) formed by linearly pressing the surface of the blank sheet S. Note that the creases may be formed with intermittent cuts. In this way, it becomes easier to fold the blank sheet S at the fold lines. Alternatively, the folded line may be formed by forming a half-cut slit only on the surface of the sheet or a slit penetrating the sheet in an intermittent linear fashion.

[0019] 1, the body 10 is formed in a rectangular cylindrical shape, and includes a pair of front and rear end walls 11, 11 and a pair of left and right side walls 12, 12. The body 10 of this embodiment is formed so that the length in the front-rear direction is greater than the length in the left-right direction.

[0020] A left side wall 12 is connected to the left edge of the front end wall 11 via a folding line. The left side wall 12 is formed perpendicular to the front end wall 11. The rear end wall 11 is connected to the rear edge of the left side wall 12 via a folding line. The rear end wall 11 is formed perpendicular to the left side wall 12. A right side wall 12 is connected to the right edge of the front end wall 11 via a folding line. The right side wall 12 is formed perpendicular to the front end wall 11. A joint piece 13 is connected to the rear edge of the right side wall 12 via a folding line (see FIG. 2). The joint piece 13 is formed in a strip shape along the rear edge of the right side wall 12.

[0021] By folding the blank sheet S (see Figure 2) at each fold line and joining the joining piece 13 to the inner surface of the rear end wall 11, a rectangular cylindrical body 10 is formed by the front end wall 11, the left side wall 12, the rear end wall 11 and the right side wall 12.

[0022] The bottom 30 has a pair of front and rear inner flaps 31, 31 connected to the lower edges of the front and rear end walls 11, 11 via fold lines, and a pair of left and right outer flaps 32, 32 connected to the lower edges of the left and right side walls 12, 12 via fold lines, respectively. The bottom portion 30 is formed by overlapping both outer flaps 32, 32 on the lower surfaces of both inner flaps 31, 31 and connecting both outer flaps 32, 32 with an adhesive means such as tape.

[0023] The top 20 is provided with a pair of front and rear end flaps 50, 50 connected to the upper edges of the front and rear end walls 11, 11 respectively via fold lines, and a pair of left and right side flaps 60, 60 connected to the upper edges of the left and right side walls 12, 12 respectively via fold lines.

[0024] 4, the side flaps 60 are folded perpendicularly toward the inside of the upper opening relative to the side walls 12. The leading edge portions of the left and right side flaps 60, 60 are disposed in the middle of the upper opening in the left-right direction. In this embodiment, the leading edges of the both side flaps 60, 60 are butted against each other, but the leading edges of the left and right side flaps 60, 60 may be spaced apart in the left-right direction.

[0025] An opening recess 61 is formed in the center of the tip edge of the side flap 60. A substantially rectangular central opening 62 is formed between the left and right side flaps 60, 60 by the opening recess 61 of the left side flap 60 and the opening recess 61 of the right side flap 60. In this way, a substantially rectangular central opening 62 is formed in the center of the top 20.

[0026] Front and rear locking recesses 63, 63 are formed in the center of the front and rear edges of the central opening 62. The left half of the locking recess 63 is formed in the left side flap 60, and the right half of the locking recess 63 is formed in the right side flap 60.

[0027] As shown in FIG. 1, the rear end flap 50 has a base end portion 51 connected to the rear end wall 11, an intermediate portion 52 connected to the base end portion 51, and a folded portion 53 connected to the intermediate portion 52.

[0028] The base end 51 is connected to the upper edge of the rear end wall 11 via a fold line. The base end 51 is formed in a rectangular shape. The base end 51 is bent vertically toward the inside of the upper opening relative to the end wall 11, and is overlapped on the upper surfaces of the rear ends of the side flaps 60, 60. The length of the base end 51 in the front-to-rear direction is such that the center of the tip edge (front edge) of the base end 51 overlaps with the bottom (rear edge) of the locking recess 63 formed on the rear edge of the central opening 62.

[0029] An intermediate portion 52 is connected to the center of the tip of the base end portion 51 via a bent line. As shown in FIG. 1, the intermediate portion 52 is bent downward with respect to the base end portion 51 (see FIG. 3) and fitted into the locking recess 63. The vertical length of the intermediate portion 52 is the same as the thickness of the side flap 60. The left-right width of the intermediate portion 52 is formed to be the same as or slightly larger than the left-right width of the locking recess 63. As shown in Fig. 5, when the base end 51 is placed on the upper surfaces of the side flaps 60, 60, and then the middle portion 52 is folded downward relative to the base end 51 as shown in Fig. 1, the middle portion 52 is pushed into the locking recess 63. As a result, the middle portion 52 is held in the locking recess 63.

[0030] As shown in FIG. 5, a folded portion 53 is provided adjacent to the tip edge of the intermediate portion 52. The folded portion 53 is formed with a tip portion 54 connected to the intermediate portion 52, and left and right protruding portions 55, 55 connected to the left and right edges of the tip portion 54, respectively.

[0031] The tip portion 54 is connected to the tip edge portion of the intermediate portion 52 via a folding line. In the end flap 50 of this embodiment, the tip portion 54 is connected to the base end portion 51 via the intermediate portion 52. The tip portion 54 is formed in a quadrangle, and the left-right width is greater than the left-right width of the intermediate portion 52. In addition, the left-right width of the tip portion 54 is equal to or less than the left-right width of the central opening 62. In this embodiment, the left-right width of the tip portion 54 is slightly smaller than the left-right width of the central opening 62.

[0032] The fold line between the tip portion 54 and the intermediate portion 52 is disposed forward of the base end edge (rear edge) of the folded-back portion 53. In other words, the intermediate portion 52 extends further toward the tip side than the base end edge of the folded-back portion 53. In addition, in the state of the blank sheet S shown in Figure 2, slits extending in the front-rear direction are formed in the left and right edges of the intermediate portion 52, and the left and right edges of the intermediate portion 52 are separated from the folded-back portion 53.

[0033] 3, the tip portion 54 is inserted into the body portion 10 through the central opening 62 and is bent backward with respect to the lower edge (tip edge) of the intermediate portion 52. When the tip portion 54 is bent backward with respect to the base end portion 51, the tip portion 54 is disposed behind the central opening 62.

[0034] 5, the protruding portion 55 is connected to the left and right edges of the tip portion 54. The protruding portion 55 is formed in a quadrangle shape and extends outward in the left-right direction beyond the central opening 62. In this manner, the left-right width of the entire folded portion 53 is greater than the left-right width of the central opening 62.

[0035] In this embodiment, as shown in FIG. 1, when the folded-back portion 53 is folded back toward the base end portion 51, the left and right edges of the folded-back portion 53 are configured to abut against the inner surface of the side wall 12. However, the left and right edges of the folded-back portion 53 do not have to abut against the inner surface of the side wall 12. In addition, in this embodiment, as shown in FIG. 3, when the folded-back portion 53 is folded back toward the base end portion 51, the tip edge portion of the folded-back portion 53 is configured to abut against the inner surface of the end wall 11, but the tip edge portion of the folded-back portion 53 does not have to abut against the inner surface of the end wall 11.

[0036] In the folded portion 53 of this embodiment, as shown in Fig. 2, left and right protruding portions 55, 55 are connected to the left and right edges of the tip portion 54 via cut lines L1, L1, respectively. The cut line L1 is a straight line with multiple cuts formed intermittently. Although each cut of the cut line L1 in this embodiment penetrates the sheet (so-called full cut line), it may also be one that does not penetrate the sheet but cuts it halfway (so-called half cut line). In the present embodiment, the cut lines L1 are cut along the lines formed on the inner surface of the blank sheet S (so-called lead lines), but it is not necessary to form lines.

[0037] 1, the front end flap 50 is configured symmetrically to the rear end flap 50. The folded-back portion 53 of the front end flap 50 is folded back toward the front with respect to the base end portion 51.

[0038] Next, a procedure for assembling the packaging box 1 of this embodiment will be described. As shown in FIG. 4, the body 10 is assembled, and with the bottom 30 open, the left and right side flaps 60, 60 are folded against the left and right side walls 12, 12. As a result, a central opening 62 is formed between the side flaps 60, 60, and front and rear locking recesses 63, 63 are formed on the front and rear edges of the central opening 62, respectively.

[0039] Next, as shown in FIG. 5, the front and rear end flaps 50, 50 are folded toward the front and rear end walls 11, 11, and overlapped on the upper surfaces of the side flaps 60, 60. As a result, the middle portion 52 of the end flap 50 is overlapped on the upper side of the locking recess 63. In addition, the tip portion 54 of the folded portion 53 is overlapped on the upper side of the central opening 62, and the left and right protruding portions 55, 55 are overlapped on the upper surfaces of the side flaps 60, 60, respectively.

[0040] 6, when the end flap 50 is placed on the upper surfaces of the side flaps 60, 60, the tip 54 of the folded-back portion 53 is pushed into the central opening 62, the overhanging portion 55 is pressed against the upper surface of the side flap 60. As a result, the overhanging portion 55 is folded at the cut line L1 in a valley fold relative to the tip 54 when viewed from above. Then, both overhanging portions 55, 55 are bent toward the tip portion 54, and the folded portion 53 passes through the central opening 62 in a state in which the width of the folded portion 53 in the left-right direction is narrowed.

[0041] As shown in FIG. 3, when folded portion 53 is inserted into body 10 through central opening 62 and folded back onto base end 51, protruding portion 55 returns to an open state in the left-right direction relative to tip end 54 due to a restoring force, and the width of folded portion 53 increases. 1, the folded-back portions 53, which are wider than the central opening 62, are disposed on the lower surfaces of the side flaps 60, 60. As shown in FIG. Furthermore, when the folded-back portion 53 is folded back onto the base end portion 51 , the intermediate portion 52 is pushed into the locking recess 63 and is held in the locking recess 63 .

[0042] In this manner, the folded portion 53 of the end flap 50 is inserted into the body portion 10 through the central opening 62, and the folded portion 53 is folded back onto the base end portion 51, thereby completing the top portion 20. After assembling the top 20, the body 10 is turned upside down, and the green onion is inserted into the body 10 from the lower opening of the body 10. Then, after assembling the bottom 30, the packaging box 1 is turned upside down, and the assembly work of the packaging box 1 is completed.

[0043] 1, in the packaging box 1 as described above, the side flaps 60, 60 are sandwiched between the base end 51 of the end flap 50 and the folded-back portion 53. In addition, in the packaging box 1 of this embodiment, the width of the folded-back portion 53 is larger than the width of the central opening 62, so that the folded-back portion 53 is unlikely to come out of the central opening 62. Therefore, in the packaging box 1 of this embodiment, the end flap 50 of the top portion 20 and the side flaps 60, 60 can be reliably connected to each other.

[0044] 6, when the tip 54 of the folded portion 53 is pushed into the central opening 62, the protruding portions 55, 55 are valley-folded at the cut lines L1, L1 relative to the tip 54 when viewed from above. This narrows the overall width of the folded portion 53, so that the folded portion 53 can be easily inserted into the central opening 62 to assemble the top 20.

[0045] In the packaging box 1 of this embodiment, the overhanging portion 55 is folded toward the tip portion 54 along the cut line L1 formed by a plurality of cuts, so that the overhanging portion 55 is valley-folded relative to the tip portion 54 when viewed from above. Furthermore, in this embodiment, the cut line L1 is formed along a ruled line formed on the inner surface of the folded-back portion 53, so that the overhanging portion 55 can be neatly folded toward the tip portion 54 at the cut line L1.

[0046] In the packaging box 1 of this embodiment, as shown in Fig. 1, the middle portion 52 of the end flap 50 is fitted and held in the locking recess 63 of the central opening 62. Also, in the packaging box 1 of this embodiment, as shown in Fig. 3, the tip edge of the folded portion 53 abuts against the inner surface of the end wall 11. This prevents the folded portion 53 from returning to a flat state relative to the base end 51, and allows the shape of the top portion 20 to be maintained even when the body portion 10 is empty.

[0047] In the packaging box 1 of this embodiment, as shown in Fig. 1, both overhanging portions 55, 55 of the end flap 50 abut against the inner surfaces of both side walls 12, 12, so the folded-back portion 53 does not rotate within the body portion 10. This prevents the folded-back portion 53 from damaging the green onions inside the body portion 10. In addition, because the overhanging portion 55 presses the body portion 10 from the inside, the shape of the packaging box 1 is well maintained and it is less likely to warp.

[0048] 6, when the folded-back portion 53 is inserted into the central opening 62, the protruding portion 55 is valley-folded at the cut line L1 relative to the tip portion 54 as viewed from above (outside). When the packaging box 1 of this embodiment is assembled, the other folded portions are mountain-folded as viewed from outside. In this manner, in the packaging box 1 of this embodiment, only the folding direction of the protruding portion 55 relative to the tip portion 54 is opposite to the folding direction of the other folding portions. In the packaging box 1 of this embodiment, when the blank sheet S shown in Fig. 2 is manufactured, each fold line is formed on the inner surface of the sheet. At this time, the cut line L1 between the tip portion 54 and the protruding portion 55 can also be formed by cutting from the inner surface side of the sheet. This eliminates the need to turn the sheet over for the processing machine, and allows each fold line and cut line L1 of the blank sheet S to be processed from the same direction, allowing the blank sheet S to be manufactured efficiently.

[0049] Although the embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and can be appropriately modified without departing from the spirit of the present invention. In the packaging box 1 of this embodiment, as shown in FIG. 1, the protruding portions 55, 55 are connected to both the left and right sides of the tip 54 of the folded portion 53, but the protruding portion 55 may be connected to only one of the left and right sides of the tip 54.

[0050] In the packaging box 1 of this embodiment, as shown in FIG. 5, the tip portion 54 of the folded portion 53 and both of the protruding portions 55, 55 are formed in a rectangular shape, but the shape is not limited thereto. In the packaging box 1 of this embodiment, an intermediate portion 52 is formed between the base end portion 51 and the folded-back portion 53 of the end flap 50, but the folded-back portion 53 may be connected to the base end portion 51 via a fold line without forming the intermediate portion 52 in the end flap 50.

[0051] The packaging box 1 of this embodiment is made of corrugated cardboard, but the packaging box may also be made of various known paperboards. [Explanation of symbols]

[0052] 1 packaging box 10. Torso 11 End Wall 12 Side wall 13 Joint piece 20 Top 30 bottom 31 Inner flap 32 Outer flap 50 End flap 51 Proximal end 52 Middle section 53 Turn-back section 54 Tip 55 Overhang 60 Side flap 61 Opening recess 62 Central opening 63 Locking recess L1 Cut line S Blank Sheet

Claims

1. A cylindrical body portion having front and rear end walls and left and right side walls; A bottom portion that closes a lower opening of the body portion; a top portion formed at an upper opening of the body portion, The top portion is front and rear end flaps connected to upper edge portions of the front and rear end walls; and left and right side flaps connected to upper edge portions of the left and right side walls, A central opening is formed between the side flaps; The end flaps include: a base end portion overlapping the upper surface of each of the side flaps; a folded portion that is inserted into the body portion through the central opening and folded back toward the base end portion; The folded portion has: A tip portion connected to the base end portion; a protruding portion that is connected to at least one of the left and right edges of the tip portion and extends outward in the left-right direction beyond the central opening, The packaging box is characterized in that the protruding portion is connected to the tip portion via a cut line.

2. The packaging box according to claim 1, The packaging box is characterized in that the cut line is formed along a line formed on the inner surface of the folded portion.

3. The packaging box according to claim 1, The folded portion has: The left and right protrusions are connected to the left and right edge portions of the tip portion via the cut lines, respectively.

4. The packaging box according to claim 1, A locking recess is formed on the front-rear edge of the central opening, a width in the left-right direction of an intermediate portion between the base end portion and the tip end portion is equal to or larger than a width in the left-right direction of the locking recess, The packaging box is characterized in that the intermediate portion is fitted into the locking recess and is held in the locking recess.

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