Packaging box

Abstract

To provide a packaging box whose bottom can be easily and reliably assembled and whose load-bearing capacity on the bottom can be increased.SOLUTION: A packaging box 1 includes a bottom part 30 having front and rear end flaps 31, 31 and left and right side flaps 32, 32. A protruding part 35 that protrudes toward the tip side is formed at one corner part of the tip of the side flap 32, and an insertion part 36 that is inserted into a connecting hole 33 of the end flap 31 is formed at the other corner part of the tip of the side flap 32. At the tip of the side flap 32, an inclined part 37 protruding toward the tip side as it moves from the protruding part 35 side toward the insertion part 36 side is formed between the protruding part 35 and the insertion part 36. The protruding part 35 of one side flap 32 enters the inner surface side of the inclined part 37 of the other side flap 32.SELECTED DRAWING: Figure 3

Description

[Technical field]

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

[0002] The bottom of a cardboard packaging box has front and rear end flaps and left and right side flaps, with insertion portions protruding from the side edges of the side flaps being inserted into connecting holes in the end flaps and protruding portions protruding from the tip edges of the side flaps fitting into the inner surface of the tip of the other side flap (see, for example, Patent Document 1).

[0003] When assembling the bottom of the above-mentioned packaging box, the side flaps are overlapped on the outer surfaces of the end flaps, the side flaps and the end flaps are tilted toward the inside of the body, and then the side flaps and the end flaps are returned to flat. In this way, the insertion parts of the side flaps are inserted into the connection holes of the end flaps, and the protruding parts of the side flaps enter the inner sides of the tips of the other side flaps, thereby connecting the both end flaps and both side flaps to assemble the bottom. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Publication number 05-011141 Summary of the Invention [Problem to be solved by the invention]

[0005] In the conventional packaging boxes described above, the area over which the protruding portions of the side flaps overlap with the inner surfaces of the other side flaps is small, resulting in low load-bearing capacity at the bottom and problems with the protruding portions of the side flaps easily coming off the other side flaps when assembling the bottom.

[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 bottom can be easily and reliably assembled and whose load-bearing capacity can be increased. [Means for solving the problem]

[0007] In order to solve the above problems, the present invention provides a packaging box comprising a cylindrical body having front and rear end walls and left and right side walls, and a bottom provided at an opening on the lower side of the body. The bottom has front and rear end flaps respectively connected to the lower edges of both end walls, and left and right side flaps respectively connected to the lower edges of both side walls and overlapped on the outer surfaces of the both end flaps. A protrusion protruding toward the tip side is formed at one corner of the tip of the side flap, and an insertion portion is formed at the other corner of the tip of the side flap. At the tip of the side flap, between the protrusion and the insertion portion, an inclined portion is formed protruding toward the tip side as it moves from the protrusion side toward the insertion portion side. The insertion portion is inserted into a connecting hole formed in the end flap. The protrusion of one of the side flaps extends into the inner surface of the inclined portion of the other of the side flaps, and the protrusion of the other of the side flaps extends into the inner surface of the inclined portion of one of the side flaps.

[0008] When assembling the bottom of the packaging box of the present invention, the side flaps are overlapped on the outer surfaces of the end flaps, and the end flaps and both side flaps are pushed into the inside of the body to be inclined, and then the end flaps and both side flaps are returned to flat. In this way, the insertion parts of the side flaps are naturally inserted into the connecting holes of the end flaps, and the protruding parts of the side flaps naturally enter the inner sides of the inclined parts of the other side flaps. Therefore, the bottom of the packaging box of the present invention can be easily and reliably assembled.

[0009] In the packaging box of the present invention, the inclined portion of the side flap juts out toward the tip as it approaches the insertion portion, so that the area where the protruding portion of one side flap overlaps the inner surface of the inclined portion of the other side flap becomes large. This makes it difficult for the protruding portion of one side flap to come off from the other side flap when assembling the bottom.

[0010] In the packaging box of the present invention, both corners of the tip of the side flap fit into the inner surface of the bottom, and the area over which the protruding portions of the side flaps overlap with the other side flaps is increased, thereby increasing the load-bearing capacity of the bottom.

[0011] The inclined portion may be formed in the entire area between the protruding portion and the insertion portion at the tip of the side flap of the packaging box, or the protruding portion may be formed in a band shape extending in the front-rear direction. In this way, it is preferable to increase the load-bearing capacity of the bottom by increasing the area where the protruding portion of one side flap overlaps with the inclined portion of another side flap. Effect of the Invention

[0012] In the packaging box of the present invention, the side flaps are less likely to come apart when assembling the bottom. Also, in the packaging box of the present invention, the overlapping area of ​​the side flaps is large, so that the bottom can be easily and reliably assembled and the load-bearing capacity of the bottom can be increased. [Brief description of the drawings]

[0013] [Figure 1] 1 is a perspective view of a packaging box according to an embodiment of the present invention, viewed from the lower 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] FIG. 2 is a bottom view showing the packaging box according to the embodiment of the present invention. [Figure 4] FIG. 2 is a bottom view of the packaging box according to the embodiment of the present invention with the side flaps open. [Diagram 5] 2 is a cross-sectional view taken along line VV of FIG. 1 showing the bottom of the packaging box according to the embodiment of the present invention. [Figure 6] 1 is a bottom view showing a state in the middle of assembling the bottom of the packaging box according to the embodiment of the present invention. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] 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.

[0015] As shown in FIG. 1, the packaging box 1 of this embodiment has a cylindrical body 10, a top 20 provided at an upper opening of the body 10, and a bottom 30 provided at a lower opening of the body 10.

[0016] The packaging box 1 of this embodiment is formed by mountain-folding or valley-folding a blank sheet S cut out from a cardboard sheet at 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.

[0017] As shown in Fig. 1, the body 10 has a pair of front and rear end walls 11, 11 and a pair of left and right side walls 12, 12. The end walls 11 and the side walls 12 are formed in a rectangular shape. The body 10 of this embodiment is formed in a rectangular cylindrical shape in a plan view (see Fig. 5).

[0018] 2, the top 20 includes a pair of front and rear inner flaps 21, 21 connected to the upper edges of the front and rear end walls 11, 11, respectively, and a pair of left and right outer flaps 22, 22 connected to the lower edges of the left and right side walls 12, 12, respectively. The top 20 is formed by overlapping the outer surfaces (top surfaces) of the inner flaps 21, 21 with the outer flaps 22, 22.

[0019] 1, the bottom 30 has front and rear end flaps 31, 31 connected to the lower edges of both end walls 11, 11, respectively, and left and right side flaps 32, 32 connected to the lower edges of both side walls 12, 12, respectively. The both side flaps 32, 32 are overlapped on the outer surfaces (lower surfaces) of the both end flaps 31, 31.

[0020] The end flap 31 of the bottom 30 is formed in a rectangular shape as shown in Fig. 4. A connecting hole 33 is formed in the end flap 31. In the front end flap 31, the connecting hole 33 is disposed to the left of the center in the left-right direction. The connecting hole 33 is a substantially trapezoidal opening. The right edge L33 of the connecting hole 33 of the front end flap 31 is inclined away from the left edge of the front end flap 31 from the front end (the end on the front end wall 11 side) toward the rear end. The connecting hole 33 is closed by a cover plate 34. The cover plate 34 of the front end flap 31 is connected to the left edge of the connecting hole 33 via a fold line L34.

[0021] The connecting hole 33 of the rear end flap 31 is formed point-symmetrically with respect to the connecting hole 33 formed in the front end flap 31. That is, in the rear end flap 31, the connecting hole 33 is disposed to the right of the center in the left-right direction, and the left edge L33 of the connecting hole 33 is inclined away from the right edge of the rear end flap 31 as it moves from the rear end to the front end.

[0022] The side flaps 32 are formed along the lower edge of the side wall 12. The bases of the side flaps 32 are formed so that their width in the front-to-rear direction narrows from the base end (the end on the side wall 12 side) toward the tip end. A protrusion 35 is formed at the rear corner of the tip of the left side flap 32, protruding further toward the tip side than the reference line L. The reference line L is an imaginary line parallel to the base end edge of the side flap 32 (the lower edge of the side wall 12). The protrusion 35 is formed in a band shape extending in the front-rear direction along the lower edge of the side wall 12.

[0023] An insertion portion 36 is formed at the front corner of the tip portion of the left side flap 32 to be inserted into the connecting hole 33 of the end flap 31 (see FIG. 3). The front edge of the insertion portion 36 is formed perpendicular to the side wall 12. In addition, the tip edge of the insertion portion 36 is inclined so as to approach the side wall 12 as it approaches the protruding portion 35. As a result, the angle formed by the straight portion of the front edge of the insertion portion 36 and the straight portion of the tip edge is an acute angle.

[0024] At the tip of the side flap 32, an inclined portion 37 is formed in the entire region between the protruding portion 35 and the tip of the insertion portion 36, protruding toward the tip side from the reference line L. The inclined portion 37 is a triangular region that protrudes toward the tip side as it moves from the protruding portion 35 side toward the insertion portion 36 side. In this embodiment, the insertion portion 36 and the inclined portion 37 are formed continuously.

[0025] The right side flap 32 is formed point-symmetrically with respect to the left side flap 32. That is, a protrusion 35 is formed at the front corner of the tip of the right side flap 32, and an insertion portion 36 is formed at the rear corner of the tip of the right side flap 32.

[0026] In the assembled state of the bottom 30 of this embodiment, as shown in Figures 3 and 5, the insertion portion 36 of the left side flap 32 is inserted from the outside into the connecting hole 33 of the front end flap 31 and fits into the inner surface of the front end flap 31. In addition, the protrusion 35 of the left side flap 32 fits into the inner surface of the inclined portion 37 of the right side flap 32. The insertion portion 36 of the right side flap 32 is inserted from the outside into the connecting hole 33 of the rear end flap 31 and fits into the inner surface of the rear end flap 31. In addition, the protrusion 35 of the right side flap 32 fits into the inner surface of the inclined portion 37 of the left side flap 32.

[0027] When assembling the bottom 30 of this embodiment, as shown in Figure 6, the both side flaps 32, 32 are overlapped on the outer surfaces of the both end flaps 31, 31, and then the both end flaps 31, 31 and the both side flaps 32, 32 are pushed toward the inside of the body 10 and inclined. At this time, the insertion portion 36 of the side flap 32 overlaps with the connecting hole 33 of the end flap 31, and the end flaps 31, 31 and both side flaps 32, 32 are inclined to a position where the protrusion 35 of the side flap 32 does not come into contact with the tip edge of the inclined portion 37 of the other side flap 32.

[0028] Thereafter, when the end flaps 31, 31 and the side flaps 32, 32 start to be returned to their flat state, the insertion portion 36 of the side flap 32 is naturally inserted into the connecting hole 33 of the end flap 31. The insertion portion 36 is inserted into the connecting hole 33 while pushing the cover plate 34 into the inside of the body 10. Furthermore, when the end flaps 31, 31 and the side flaps 32, 32 begin to return to their flat state, the protruding portion 35 of one side flap 32 naturally fits into the inner surface of the inclined portion 37 of the other side flap 32.

[0029] In the packaging box 1 of this embodiment, when the end flaps 31, 31 and the side flaps 32, 32 begin to be returned to a flat state, the timing at which the insertion portion 36 of the side flap 32 begins to be inserted into the connecting hole 33 of the end flap 31 and the timing at which the protrusion 35 of the side flap 32 begins to penetrate into the inner surface of the inclined portion 37 of the other side flap 32 are approximately simultaneous.

[0030] Then, after the side flaps 32, 32 and the end flaps 31, 31 are once pushed toward the inside of the body 10, the end flaps 31, 31 and the side flaps 32, 32 can be returned to a flat position as shown in Figure 3, thereby making it easy to assemble the bottom 30.

[0031] In the packaging box 1 of this embodiment, the inclined portion 37 of the side flap 32 protrudes further toward the tip side than the reference line L as it moves from the protruding portion 35 side toward the insertion portion 36 side. In addition, in the packaging box 1 of this embodiment, an inclined portion 37 is formed at the tip of the side flap 32 over the entire area between the protrusion 35 and the tip of the insertion portion 36, and the protrusion 35 is formed in a band shape extending in the front-to-rear direction. As a result, in the packaging box 1 of this embodiment, the area where the protruding portion 35 of the side flap 32 overlaps with the inner surface of the inclined portion 37 of the other side flap 32 becomes large. As a result, compared to a case where the tip edge of the side flap 32 is formed at the position of the reference line L, the protruding portion 35 of the side flap 32 is less likely to come off from the other side flap 32 when the bottom 30 is assembled.

[0032] In the packaging box 1 of this embodiment, both corners of the tip of the side flap 32 fit into the inner surface of the bottom 30, and the area over which the protruding portion 35 of the side flap 32 overlaps with the inner surface of the other side flap 32 becomes larger, thereby increasing the load-bearing capacity of the bottom 30.

[0033] 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. 4, an inclined portion 37 is formed in the entire area between the protrusion 35 and the insertion portion 36 of the side flap 32, but in the area between the protrusion 35 and the insertion portion 36, an inclined portion may be formed only in the area on the side of the insertion portion 36.

[0034] 5, the packaging box 1 of this embodiment has a body 10 formed into a quadrangular tubular shape, but there is no limitation on the number of corners of the body 10. For example, an inclined wall may be provided between the end wall 11 and the side wall 12 to form the body 10 into a hexagonal or octagonal tubular shape.

[0035] In the packaging box 1 of this embodiment, as shown in FIG. 1, a top 20 is provided, but the box may be formed in a tray shape with an opening at the upper side of the body 10 without providing a top 20.

[0036] The packaging box 1 of this embodiment is made of corrugated cardboard, but the packaging box of the present invention can be formed from various known paperboards. [Explanation of symbols]

[0037] 1 packaging box 10. Torso 11 End Wall 12 Side wall 20 Top 21 Inner flap 22 Outer flap 30 bottom 31 End flap 32 Side flap 33 Connection hole 34 Lid plate 35 Protrusion 36 Insertion part 37 Slope S Blank Sheet

Claims

1. A cylindrical body portion having front and rear end walls and left and right side walls; A bottom portion is provided at an opening on the lower side of the body portion, The bottom portion is front and rear end flaps respectively connected to lower edge portions of both end walls; left and right side flaps respectively connected to the lower edge portions of the side walls and overlapping outer surfaces of the end flaps; A protrusion protruding toward the tip end is formed at one corner of the tip end of the side flap, An insert portion is formed at the other corner of the tip of the side flap, At the tip of the side flap, between the protruding portion and the insertion portion, an inclined portion is formed protruding toward the tip side as it moves from the protruding portion side toward the insertion portion side, The insert portion is inserted into a connecting hole formed in the end flap, The protruding portion of one of the side flaps is inserted into the inner surface side of the inclined portion of the other of the side flaps, A packaging box, characterized in that the protruding portion of the other side flap is recessed into the inner surface side of the inclined portion of one of the side flaps.

2. The packaging box according to claim 1, The packaging box according to claim 1, wherein the inclined portion is formed at the tip of the side flap over the entire area between the protrusion and the insertion portion.

3. The packaging box according to claim 1, The packaging box is characterized in that the protrusion is formed in a band shape extending in the front-rear direction.

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