Packing box

Abstract

To provide a packing box than can be easily made although corner portions of a trunk part thereof are increased.SOLUTION: A packing box 1 comprises a cylindrical trunk part 10, and blocking parts 20 blocking either of two open ends 10a of the trunk part 10. The trunk part 10 has a pair of first side plates 11 opposing to each other and a pair of second side plates 12 connected with the pair of first side plates 11 through fold lines (a) of the trunk part. The blocking parts 20 have flaps 21 connected to the first side plates 11 through flap fold lines (b1) and folded inward at the flap fold lines (b1). Additional fold lines (c) extending in the same direction as the fold lines (a) of the trunk part are formed in at least either of the pair of first side plates. Flaps 21 have force receiving parts 21a that receive force from one site of the packing box 1 accompanying change of relative positions or relative attitudes of parts of the packing box 1 in a making procedure. The additional fold lines (c) are folded back when the force receiving parts 21a receive the force.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a packaging box for storing various items. [Background technology]

[0002] Conventionally, grooved packaging boxes for storing various items have been in widespread use, which are made (assembled) by folding a blank sheet with multiple grooves (slits) cut from one end. This grooved packaging box is configured such that a tubular body is formed by gluing a joint provided at an end of the blank sheet where no grooves are formed to the opposite end, and at least one of the open ends at both axial ends of the body is closed by folding a flap formed by cutting the grooves.

[0003] Such grooved packaging boxes generally have a square tubular (rectangular) body folded at four places, but there are also ones with an octagonal or hexagonal tubular body (see, for example, Patent Document 1). In this way, by forming the body into an octagonal tubular shape or the like and increasing the number of corners (folded parts), it is possible to increase resistance to buckling in the axial direction (the direction connecting the two open ends of the body).

[0004] In addition, by increasing the number of corners in the body, it is possible to shorten the circumference of the body while maintaining the same storage efficiency for items. For example, by chamfering the square-shaped body into an octagonal tube, it is possible to shorten the circumference of the body while reducing the dead space near the corners. This allows the packaging box to have the same storage efficiency, but with a reduced area of ​​blank sheets, which reduces material costs. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2017-61341 A Summary of the Invention [Problem to be solved by the invention]

[0006] However, when the number of corners of the body is increased to form an octagonal tube shape, etc., there is a problem that box making becomes difficult. Specifically, when the body is a typical rectangular tube shape, the four side panels of the body that face each other are maintained approximately parallel to each other, so it is easy to maintain the appropriate state in which the four corners are bent at approximately right angles, but when the number of corners is increased, the degree of freedom of the posture of each side panel increases, so it is necessary to bend each corner at an appropriate angle (an angle other than a right angle) and maintain that state, which makes box making time-consuming and labor-intensive.

[0007] In this regard, the packaging box described in Patent Document 1 is supported by the side edges of the inner flaps so that the shape of the body after box making is maintained as an octagonal tube or the like. However, when folding the inner flaps during box making, it is necessary to keep the body in a suitable octagonal tube or the like shape so that the inner flaps enter the inside of the body and the side edges come into contact with the inner surface, which does not make box making easier.

[0008] In view of the above circumstances, the present invention aims to provide a packaging box that can be easily manufactured while increasing the number of corners of the body. [Means for solving the problem]

[0009] The packaging box of the present invention has a cylindrical body and a closing portion that closes one of the two open ends of the body, wherein the body has a pair of first side panels facing each other and a pair of second side panels that are connected to the pair of first side panels via a body fold line, the closing portion has a flap that is connected to the first side panels via a flap fold line and is folded inward at the flap fold line, at least one of the pair of first side panels is provided with an additional fold line extending in the same direction as the body fold line, the flap has a force receiving portion that receives force from other parts of the packaging box as the relative position or relative posture of each part of the packaging box changes during the box-making procedure, and the additional fold line is folded when the force receiving portion receives force.

[0010] According to the packaging box of the present invention, by appropriately setting the dimensions or shape of the flaps, it is possible to utilize the relative positions or relative postures of the various parts of the packaging box that change during normal box-making procedures to fold the additional fold lines in a mountain fold (so that the front side is convex) and increase the number of corners in the body. In other words, according to the packaging box of the present invention, while increasing the number of corners in the body, there is no need to provide a separate procedure for forming the additional corners, and the box can be easily made using approximately the same procedure as when the body is a rectangular tube.

[0011] In addition, in the packaging box of the present invention, it is preferable that the closing portion has a pair of the flaps whose tips abut against each other, and the force receiving portion is provided at the tips of the flaps. By appropriately setting the distance from the flap fold line to the tips of the flaps, when the flaps are folded at the flap fold line to form the closing portion during box making, the tips of the pair of flaps can be butted against each other to push the pair of first side panels in a direction away from each other. In other words, when forming the closing portion, simply by folding the pair of flaps at the flap fold line with their tips butted against each other, the additional fold line can be folded in a mountain fold, and a corner can be added to the body.

[0012] In the packaging box of the present invention, it is also preferable that the flap has an engagement portion that engages with another portion of the packaging box, and the force receiving portion is provided on the engagement portion. With this, even if the closing portion is configured with an American lock in which multiple flaps engage with each other, the additional fold line can be folded in a mountain fold when the closing portion is formed, and a corner portion can be added to the body portion.

[0013] In the packaging box of the present invention, it is also preferable that the flap has an adhesive part that is adhered to another part of the packaging box, and the force-receiving part is composed of the adhesive part. With this, even if the closing part is composed of a bottom lock where a plurality of flaps are adhered to each other, the additional fold line can be folded in a mountain fold when the closing part is formed, and a corner part can be added to the body part.

[0014] In the packaging box of the present invention, it is preferable that the additional crease line has a portion that is not parallel to the body crease line. This makes it possible to easily form the additional crease line that is less prone to bending than the body crease line, thereby preventing the additional crease line from accidentally bending when the body crease line is folded, and facilitating box making.

[0015] In the packaging box of the present invention, it is preferable that the additional fold line is provided along a line that protrudes toward the center of the first side plate.

[0016] Conventionally, in packaging boxes in which the body is formed into an octagonal tube shape by providing inclined surfaces such as chamfered four corners of the body, there was a problem that when compressive force in the axial direction (the direction connecting the two open ends of the body) is applied by stacking them up and down, the side panels between the inclined surfaces are likely to buckle so as to be recessed inward. In response to this, by providing the additional fold line along a line that is convex toward the center of the first side panel, when the additional fold line is folded, the area between the additional fold lines in the first side panel can be made to bulge slightly outward and tensile stress in the axial direction can be generated on the surface side of the area. In other words, with this configuration, it is possible to create in advance a state exactly opposite to the state in which the first side panel is buckled so as to be recessed inward due to axial compressive force, and therefore the buckling of the first side panel can be suppressed.

[0017] In the packaging box of the present invention, it is preferable that the additional fold line has a portion located closer to the center of the first side plate than both ends of the flap fold line. This makes it possible to support the first side plate with the flap so that the additional fold line is less likely to bend, and therefore makes it possible to easily configure the additional fold line to be less likely to bend than the body fold line, thereby preventing the additional fold line from being accidentally bent when the body fold line is folded. Effect of the Invention

[0018] According to the packaging box of the present invention, it is possible to obtain the excellent effect that the box can be easily manufactured while increasing the number of corners of the body. [Brief description of the drawings]

[0019] [Figure 1] 1 is a schematic perspective view of a packaging box according to one embodiment of the present invention. [Diagram 2] FIG. [Diagram 3] 1A to 1C are schematic perspective views showing a procedure for manufacturing a packaging box. [Figure 4] 1A to 1C are schematic perspective views showing a procedure for manufacturing a packaging box. [Diagram 5]11A to 11C are schematic diagrams showing modified examples of the packaging box. [Figure 6] 11A to 11C are schematic diagrams showing modified examples of the packaging box. [Figure 7] 11A to 11C are schematic diagrams showing modified examples of the packaging box. [Figure 8] 11A to 11C are schematic diagrams showing modified examples of the packaging box. [Figure 9] FIG. 11 is a schematic diagram showing a modified example of the packaging box. [Figure 10] 13A and 13B are schematic diagrams showing modified examples of the packaging box. [Figure 11] FIG. 11 is a schematic diagram showing a modified example of the packaging box. [Figure 12] 13A and 13B are schematic diagrams showing modified examples of the packaging box. [Figure 13] FIG. 11 is a schematic diagram showing a modified example of the packaging box. [Figure 14] 13A and 13B are schematic diagrams showing modified examples of the packaging box. [Figure 15] FIG. 11 is a schematic diagram showing a modified example of the packaging box. [Figure 16] 13A and 13B are schematic diagrams showing modified examples of the packaging box. [Figure 17] 13A and 13B are schematic diagrams showing modified examples of the packaging box. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings. Fig. 1 is a schematic perspective view of a packaging box 1 according to one embodiment of the present invention, and Fig. 2 is a development view of the packaging box 1, showing the surface of a blank sheet 1x before the packaging box 1 is made into a box.

[0021] The packaging box 1 of this embodiment is a grooved type also called A type, and is made of double-sided corrugated cardboard consisting of a front liner, a back liner, and a core. The packaging box 1 is made (assembled) into a box shape by folding a flat blank sheet 1x formed by groove-cutting and scoring the double-sided corrugated cardboard.

[0022] 1, the packaging box 1 is composed of an octagonal cylindrical body 10 and two closing portions 20 that close two open ends 10a at both axial ends (the vertical direction in FIG. 1) of the body 10. In this embodiment, since the axial direction of the body 10 (the direction connecting the two open ends 10a) is the vertical direction, the two closing portions 20 form the top plate 1a and the bottom plate 1b of the packaging box 1, respectively.

[0023] The body 10 is composed of a pair of opposing long side plates 11 (first side plates of the present invention) and a pair of opposing short side plates 12 (second side plates of the present invention). Therefore, the pair of short side plates 12 connect the pair of long side plates 11 at both ends in the circumferential direction, and the pair of long side plates 11 connect the pair of short side plates 12 at both ends in the circumferential direction. The long side plates 11 and the short side plates 12 are each formed into a rectangular plate shape with different dimensions in the circumferential direction of the body 10.

[0024] The body 10 is configured into an octagonal cylindrical shape by providing two additional corners 14 on each of the two long side plates 11 in addition to the four corners 13 between the long side plates 11 and the short side plates 12. Therefore, in the packaging box 1 after box making, the short side plates 12 are approximately flat, while the long side plates 11 are folded in two places.

[0025] In this embodiment, the additional corners 14 are formed along a V-shaped line with a bent middle portion so as to be convex toward the center of the long side panel 11. As a result, the long side panel 11 has a region between the two additional corners 14 that bulges outward slightly, and a region between the corners 13 and the additional corners 14 that is recessed inward slightly.

[0026] The closure section 20 is composed of a pair of long flaps 21 (flaps of the present invention) and a pair of short flaps 22 overlapped inside the pair of long flaps 21. The long flaps 21 and the short flaps 22 are each configured as a rectangular plate having different dimensions in the circumferential direction of the body section 10, and in this embodiment, the long flaps 21 are so-called outer flaps, and the short flaps 22 are so-called inner flaps.

[0027] The closing portion 20 is configured so that the entire open end 10a is closed by closing the pair of long flaps 21 with their tips 21a (force receiving portions of the present invention) abutting against each other. The closing portion 20 has an octagonal outer shape that matches the shape of the body portion 10 by appropriately deforming the peripheries of both circumferential ends on the base end side of the long flaps 21.

[0028] As shown in Fig. 2, in the blank sheet 1x, the long side plates 11 and the short side plates 12 are arranged alternately in the X direction (left-right direction in Fig. 2), which is the circumferential direction of the body 10. In this embodiment, the long side plates 11 and the short side plates 12 are arranged in the following order from the left in Fig. 2: long side plate 11, short side plate 12, long side plate 11, short side plate 12, and a joint 15 is arranged to the left of the leftmost long side plate 11. This joint 15 is to be bonded to the rightmost short side plate 12 to form the cylindrical body 10.

[0029] The long flaps 21 are arranged on both sides (upper and lower sides in FIG. 2) of the blank sheet 1x in the Y direction (upper and lower directions in FIG. 2) perpendicular to the X direction with respect to the long side plate 11. The short flaps 22 are arranged on both sides of the blank sheet 1x in the Y direction with respect to the short side plate 12. Therefore, a pair of long flaps 21 and a pair of short flaps 22 constituting the closure portion 20 are arranged on both sides of the blank sheet 1x in the y direction.

[0030] Adjacent long side panels 11, short side panels 12, and seams 15 are connected to each other via a body fold line a. The long flap 21 is connected to the long side panel 11 via a long flap fold line b1, and the short flap 22 is connected to the short side panel 12 via a short flap fold line b2. The long flap 21 and the short flap 22 are also divided in the X direction by slit-like grooves 23 cut into the blank sheet 1x at three locations on both ends in the y direction so as to extend in the y direction.

[0031] In other words, the long side panel 11, the short side panel 12, the seam 15, the long flap 21 and the short flap 22 are defined by the body fold line a, the long flap fold line b1, the short flap fold line b2 and the groove 23 provided in the blank sheet 1x.

[0032] The body fold line a is folded during box making to form the corner 13. The body fold line a is provided on a straight line extending in the Y direction so as to connect the inner ends of the grooves 23 adjacent to each other in the Y direction.

[0033] The long flap fold line b1 and the short flap fold line b2 are for folding the long flap 21 and the short flap 22 during box making to form the closure portion 20. The long flap fold line b1 and the short flap fold line b2 are provided on a straight line extending in the X direction so as to connect the inner ends of the grooves 23 adjacent to each other in the X direction.

[0034] In this embodiment, the long flap fold line b1 and the short flap fold line b2 are arranged on the same straight line on each side in the Y direction, but they may be arranged offset in the Y direction, taking into account the thickness of the material when overlapped.

[0035] In this embodiment, the body fold line a, the long flap fold line b1 and the short flap fold line b2 are composed of pressed lines provided on the back surface of the blank sheet 1x (the surface that will become the inner surface of the packaging box 1), similar to a typical grooved packaging box.

[0036] Two additional fold lines c are provided in the long side panel 11 near the body fold line a. These additional fold lines c are for forming additional corners 14, and are provided so as to extend in the Y direction, i.e., in the same direction as the body fold line a. In addition, both ends of the additional fold line c are connected to the long flap fold line b1.

[0037] In this embodiment, the additional fold line c is formed along a V-shaped line with a bent middle portion so as to be convex toward the center of the long side panel 11. Therefore, the additional fold line c in this embodiment has a portion that is not parallel to the body fold line a, and also has a bent portion.

[0038] In this way, by providing the additional fold line c with a portion that is not parallel to the body fold line a, or by providing a bent or curved portion, the additional fold line c can be configured to be more difficult to bend than the body fold line a. And, as will be described in detail later, by configuring the additional fold line c to be more difficult to bend than the body fold line a, it becomes possible to prevent the additional fold line c from accidentally bending when the body fold line a is folded during box making, thereby facilitating box making.

[0039] Furthermore, in this embodiment, the additional fold line c is provided closer to the center of the long side panel 11 than both ends of the long flap fold line b1, making it more difficult to bend. By providing the additional fold line c in this manner, the connecting range (range in the X direction) of the long side panel 11 and the long flap 21 can be set to a range straddling the additional fold line c. This makes it possible for both side portions (both sides in the X direction) of the long side panel 11 sandwiching the additional fold line c to be supported by the long flap 21 that does not have a fold line, making it more difficult to bend the additional fold line c.

[0040] However, if the additional fold line c is too difficult to bend, it becomes difficult to form the additional corner 14 by bending the additional fold line c. Therefore, in this embodiment, the additional fold line c is formed from a half-cut line (a cut line that does not penetrate the material in the thickness direction) provided on the back surface of the blank sheet 1x, thereby appropriately adjusting the difficulty of the additional fold line c, thereby achieving both the difficulty of bending when bending the body fold line a and the ease of bending when forming the additional corner 14. Specifically, in this embodiment, the additional fold line c is formed from a perforated half-cut line that is provided with intermittent cuts that penetrate only the back liner of the cardboard. Note that by forming the additional fold line c from a half-cut line provided on the back surface and preventing cuts, grooves, etc. from occurring on the surface, the appearance of the packaging box 1 can be prevented from being impaired.

[0041] Two auxiliary fold lines d (deformation inducing portions of the present invention) are provided on the long flap 21 on the long flap fold line b1 side. The auxiliary fold lines d are provided to induce deformation corresponding to the bending of the additional fold line c around themselves by bending themselves. The auxiliary fold lines d are provided along straight lines extending from one end of the additional fold line c toward the side end 21c closer to the additional fold line c so as to gradually move away from the long flap fold line b1.

[0042] In other words, the auxiliary fold line d is provided so as to branch off obliquely from the long flap fold line b1. The auxiliary fold line d is also connected to the additional fold line c. As a result of providing the auxiliary fold line d close to the long flap fold line b1 in this manner, the area between them is more easily deformed than other areas.

[0043] In this embodiment, the auxiliary fold line d is also provided to adjust the difficulty of bending the additional fold line c. Also, by providing the auxiliary fold line d, the bending of the long flap fold line b1 is not hindered even if the additional fold line c is provided closer to the center of the long side panel 11 than both ends of the long flap fold line b1.

[0044] In this embodiment, the auxiliary fold line d is composed of a pressed line provided on the back surface of the blank sheet 1x (the surface that will become the inner surface of the packaging box 1), but the auxiliary fold line d may also be composed of other lines, such as a half-cut line continuing from the additional fold line c.

[0045] The distance L1 from the long flap fold line b1 to the tip 21a of the long flap 21 is set to be greater than 1 / 2 the distance L2 from the body fold line a to the body fold line a of the short side panel 12, because the long side panel 11 is folded at the additional fold line c. In other words, the sum of the distances L1 to the tips 21a of the long flaps 21 in the pair of long flaps 21, i.e., twice L1, is set to be greater than the distance L2.

[0046] Next, there will be described a procedure for manufacturing the packaging box 1. Figures 3A to 3C and Figures 4A to 4C are schematic perspective views showing the procedure for manufacturing the packaging box 1.

[0047] In the manufacturing process of the packaging box 1, first, adhesive is applied to the surface of the joint 15, and then the long side plate 11 and the short side plate 12 at both ends in the X direction are folded along the body crease line a, and the joint 15 is adhered to the back surface of the short side plate 12, forming a cylindrical body 1y in a folded state in two layers as shown in Fig. 3A. This operation is usually performed by machine, along with printing, scoring, and grooving. The subsequent operations may be performed manually or by machine.

[0048] Next, the folded tubular body 1y is opened by moving the long side panels 11 apart, and as shown in Fig. 3B, the four body crease lines a are folded at approximately right angles to form a square tubular body 10 having four corners 13. As described above, the additional crease lines c are configured to be less likely to bend than the body crease lines a, so that only the body crease lines a can be easily folded at approximately right angles and maintained in that state without the need for special procedures.

[0049] Next, the closing portion 20 constituting the bottom plate 1b is formed. In forming the closing portion 20, first, the pair of short flaps 22 on the bottom plate 1b side are folded inward at the short flap fold line b2 so that the short flap fold line b2 is folded at a substantially right angle. Next, the pair of long flaps 21 on the bottom plate 1b side are folded inward at the short flap fold line b2 so that the tips 21a are butted against each other (contacted) as shown in FIG. 3C.

[0050] Then, with the tips 21a facing each other (contacting each other), the pair of long flaps 21 are folded until the long flap fold lines b1 form a substantially right angle, and the long flaps 21 are fixed to the body 10 or the short flaps 22 with adhesive tape, glue, or the like (not shown). This forms the closure portion 20 that constitutes the bottom plate 1b.

[0051] In addition, by folding the pair of long flaps 21 until the long flap crease line b1 is at a substantially right angle with the tips 21a facing each other, as shown in FIG. 4A, the pair of long flaps 21 receive a force that pushes against each other at the tips 21a, and as a result, the bottom plate 1b side of the pair of long side plates 11 is pushed in a direction away from each other. Since both ends of the pair of long side plates 11 in the circumferential direction are connected by the short side plates 12, approximately half of the bottom plate 1b side of the additional crease line c is folded in a mountain fold, and the additional corner portion 14 is partially formed. As described above, the additional crease line c is composed of a half-cut line, so that when the long side plate 11 is pushed by the bending of the long flap 21, it is smoothly bent. In addition, by folding the bottom plate 1b side of the additional crease line c, the bottom plate 1b side of the pair of short side plates 12 is drawn toward each other.

[0052] In addition, the auxiliary fold line d is bent in a mountain fold in conjunction with the bending of the long flap fold line b1 and the additional fold line c, so that the area around the auxiliary fold line d is bent in a mountain fold and the area around the adjacent long flap fold line b1 is bent in a valley fold, inducing a deformation in which the bottom plate 1b is crushed in an S-shape. As a result, the outer shape of the bottom plate 1b becomes an octagon corresponding to the formation of the additional corner portion 14.

[0053] In this embodiment, the auxiliary fold line d connected to the additional fold line c is provided to branch off from the long flap fold line b1 as described above, so that the auxiliary fold line d bends smoothly in conjunction with the bending of the long flap fold line b1 and the additional fold line c, and deformation corresponding to the bending of the additional fold line c occurs. In addition, the long side panel 11 is connected to and supported by the long flap 21 between the body fold line a and the additional fold line c, so that the bent state of the additional corner portion 14 is stably maintained.

[0054] By forming the closing portion 20 constituting the bottom plate 1b, the cylindrical body 1y becomes an open box 1z capable of accommodating contents (not shown). After the contents are accommodated in the open box 1z, the closing portion 20 constituting the top plate 1a is formed in the same manner as the closing portion 20 constituting the bottom plate 1b.

[0055] That is, as shown in Fig. 4B, the pair of short flaps 22 on the table top 1a side are folded along the short flap fold line b2, and then the pair of long flaps 21 on the table top 1a side are folded along the long flap fold line b1 to butt the tips 21a together. Then, the pair of long flaps 21 are folded in this state until the long flap fold line b1 forms a substantially right angle, and are fixed to the body 10 or the short flaps 22.

[0056] This forms the closing portion 20 that constitutes the top plate 1a. The top plate 1a sides of the pair of long side plates 11 are pushed in a direction away from each other, and the unfolded portion of the top plate 1a side of the additional fold line c is folded in a mountain fold, and the top plate 1a sides of the pair of short side plates 12 are pulled toward each other. This forms the additional corners 14 as a whole, and the octagonal tubular body 10 is formed. The deformation induced by the bending of the auxiliary fold line d also causes the outer shape of the top plate 1a to become octagonal. As a result, the packaging box 1 is completed as shown in FIG. 4C.

[0057] In this way, the packaging box 1 of this embodiment can be easily manufactured in a manner similar to that of a typical grooved packaging box having a rectangular cylindrical body, even though the body 10 is configured to be an octagonal cylindrical shape. In particular, the additional fold line c is folded as the closing portion 20 is formed, and the additional corner portion 14 appears, so that the box can be easily manufactured either manually or by machine.

[0058] The completed packaging box 1 has four additional corners 14 in addition to the four corners 13, and thus has a higher axial (vertical) compressive strength than a general packaging box having only four corners 13. In particular, in this embodiment, the long side panels 11 and the long flaps 21 are connected even between the body fold line a and the additional fold line c, so that the axial compressive strength is higher than that of a general packaging box having an octagonal cylindrical body. Furthermore, the packaging box 1 has four additional corners 14 in addition to the four corners 13, and thus the circumferential length of the body 10 is shortened to reduce material costs, while the reduction in volume is limited to the reduction in dead space, so that the same storage efficiency as a general packaging box having only four corners 13 is maintained.

[0059] Furthermore, in this embodiment, the additional fold line c that forms the additional corner portion 14 is arranged along a curved L-shaped line that is convex toward the center of the long side panel 11, thereby eliminating the problems that arise when the body portion 10 is configured into an octagonal cylindrical shape.

[0060] Specifically, in a packaging box in which the body is formed into an octagonal cylindrical shape by providing inclined surfaces, as if chamfered, on the four corners of the body, when the boxes are stacked one on top of the other and compressive force is applied in the axial direction (the direction connecting the two open ends of the body), the side panels between the inclined surfaces tend to buckle and sink inward, which is a problem that is particularly noticeable when the axial dimension of the body is long.

[0061] In contrast, in this embodiment, the additional corners 14 are formed along the additional fold lines c that are bent in a dogleg shape so as to be convex toward the center of the long side panels 11, so that the areas between the additional corners 14 in the long side panels 11 bulge slightly outward and generate axial (vertical) tensile stress on the surface side of the areas, as shown in Fig. 4C. This allows the stresses generated in the long side panels 11 when axial compressive force is applied to the packaging box 1 to be appropriately balanced, effectively preventing buckling of the long side panels 11.

[0062] That is, the packaging box 1 of this embodiment can be manufactured in the same manner as a typical grooved packaging box while certainly achieving the effect of making the body 10 into an octagonal tube shape. In particular, in this embodiment, since the box can be folded separately on the bottom plate 1b side and the top plate 1a side, it can be easily folded even at the bent additional fold line c.

[0063] Next, there will be described modified examples of the packaging box 1. FIGS.

[0064] 5A-C and 6A-C are schematic perspective views showing modified examples of the additional fold line c. The type of line along which the additional fold line c runs is not particularly limited, and various straight lines, curved lines, and combinations thereof can be used. For example, as shown in FIG. 5A, the additional fold line c may run along a curved line in an arc, or may run along a line that is a combination of a straight line parallel to the body fold line a and a straight line (or curve) that is not parallel to the body fold line a.

[0065] Additionally, the additional fold line c preferably has a portion that is not parallel to the body fold line a or a bent or curved portion, making it more difficult to bend than the body fold line a, but may be a straight line parallel to the body fold line a, as shown in Fig. 5C. Even in this case, it is possible to make the additional fold line c more difficult to bend than the body fold line a, for example, by providing the additional fold line c closer to the center of the long side panel 11 than both ends of the long flap fold line b1. Furthermore, when the axial dimension (vertical dimension) of the body 10 is relatively short, buckling of the long side panel 11 is also less likely to occur.

[0066] Although not shown in the figures, the additional fold line c may be composed of a wavy half-cut line provided along a predetermined curve or straight line, or an arc-shaped cut line provided intermittently along a predetermined curve or straight line. The additional fold line c may be provided along a straight line that is not parallel to the body fold line a. The additional fold line c may be composed of a pressed crease line, or may be composed of a full cut line (a cut line that penetrates the material in the thickness direction) if the appearance is not an issue.

[0067] The number and arrangement of the additional fold lines c are not particularly limited, and any number and arrangement may be adopted. For example, as shown in Fig. 6A, one additional fold line c may be provided on each of the pair of long side plates 11, and the body 10 may be configured into a hexagonal tube shape. Also, as shown in Fig. 6B, the additional fold line c may be provided on only one of the pair of long side plates 11.

[0068] 6C, the additional fold line c may be such that its end on the bottom plate 1b side (or top plate 1a side) connects to the body fold line a. In this case, only the sum of the distance L1 between the pair of long flaps 21 on the top plate 1a side (or top plate 1a side) may be made larger than L2. Although not shown, when an additional fold line c is provided whose end on the bottom plate 1b side (or top plate 1a side) connects to the long flap fold line b1, only the sum of the distance L1 between the pair of long flaps 21 on the top plate 1a side (or bottom plate 1b side) may be made larger than L2.

[0069] Although not shown in the drawings, the first side panel of the present invention on which the additional fold line c is provided may be the short side panel 12. The long flaps 21 may be so-called inner flaps, and the distance L1 between the pair of long flaps 21 may be different. The short flaps 22 may be omitted. The packaging box 1 may have only the bottom panel 1b.

[0070] 7A to 7C and 8A to 8C are schematic diagrams showing modified examples of the auxiliary fold line d, and show enlarged corners on the long flap fold line b1 side of the long side panel 11 and the long flap 21. The type of line along which the auxiliary fold line d follows is not particularly limited, and various straight lines, curves, and combinations thereof can be used.

[0071] The auxiliary fold line d may be along a line consisting of an arc-shaped portion that extends from one end of the additional fold line c in an arc-like shape and a straight portion that extends from the arc-shaped portion to the side end 21c approximately parallel to the long flap fold line b1, as shown in Fig. 7A for example. By making the auxiliary fold line d extend approximately continuously from one end of the additional fold line c in this way, it is possible to improve the interlocking between the bending of the additional fold line c and the bending of the auxiliary fold line d. In addition, by providing a straight portion that is approximately parallel to the long flap fold line b1 together with the arc-shaped portion, it is possible to ensure the interlocking between the bending of the long flap fold line b1 and the bending of the auxiliary fold line d while improving the interlocking of the additional fold line c.

[0072] Also, the auxiliary fold line d may be a straight line extending substantially parallel to the long flap fold line b1, as shown in Fig. 7B. In this case, the auxiliary fold line d may be bent in conjunction with the bending of the long flap fold line b1, and the ease of bending of the auxiliary fold line d may be adjusted by adjusting the length of the auxiliary fold line d. Furthermore, the auxiliary fold line d may be a combination of the example shown in Fig. 7A and the example shown in Fig. 7B, as shown in Fig. 7C.

[0073] Also, the auxiliary fold line d may be provided on the long side panel 11, as shown in FIG. 8A. In this example, the auxiliary fold line d is provided so as to branch diagonally from the long flap fold line b1 and extend to the body fold line a. In addition, the auxiliary fold line d in this example is connected to the additional fold line c. When the auxiliary fold line d is provided in this way, the auxiliary fold line d is bent into a valley fold in conjunction with the bending of the long flap fold line b1 and the additional fold line c, thereby inducing a deformation in which the periphery of the auxiliary fold line d is a valley fold and the periphery of the adjacent long flap fold line b1 is a mountain fold and is crushed so as to be folded into an S-shape.

[0074] 8B and 8C, an auxiliary full cut line d1 may be provided extending from one end of the long flap fold line b1 closer to the additional fold line c toward the long side panel 11, together with the auxiliary fold line d. Providing the auxiliary full cut line d1 makes it possible to partially release the constraint of the long side panel 11 by the short side panel 12, thereby appropriately increasing the degree of freedom of deformation of the long side panel 11 and the long flap 21. This facilitates deformation of the long flap 21 or the long side panel 11 in response to bending of the additional fold line c, and allows appropriate deformation to occur.

[0075] Furthermore, as shown in Fig. 8C, by providing the auxiliary fold line d so as to connect with the auxiliary full cut line d1, it is possible to link the bending of the auxiliary fold line d with the displacement deformation at the auxiliary full cut line d1. This makes it possible to more reliably cause the deformation of the long flap 21 or the long side panel 11 corresponding to the bending of the additional fold line c.

[0076] 8B and 8C, the auxiliary fold line d connected to the additional fold line c is provided to branch off obliquely from the long flap fold line b1, but other types of auxiliary fold lines d may be combined with the auxiliary full cut line d1. The direction in which the auxiliary full cut line d1 extends may be along the body fold line a or the long flap fold line b1, but from the viewpoint of preventing breakage starting from the auxiliary full cut line d1, it is preferable that the auxiliary full cut line d1 extend in an oblique direction between the body fold line a and the long flap fold line b1.

[0077] Although not shown in the figures, the auxiliary fold lines d may be provided in multiple numbers, and may be provided on both the long flaps 21 and the long side panels 11. The auxiliary fold lines d may not reach the side ends 21c, the body fold lines a, or the auxiliary full cut lines d1. Instead of the auxiliary fold lines d, the deformation induced portion may be formed from an area that has been subjected to step-flattening, or the deformation induced portion may be formed from the auxiliary fold lines d and an area that has been subjected to step-flattening.

[0078] Fig. 9 and Fig. 10A and B show an example of a case where the packaging box 1 is configured so as to be able to be assembled without using adhesive tape, adhesive, etc. Fig. 9 is a development view of the packaging box 1 of this example, and shows the surface of the blank sheet 1x before the packaging box 1 is assembled. Fig. 10A is a schematic diagram showing the top plate 1a of the packaging box 1, and Fig. 10B is a schematic diagram showing the bottom plate 1b of the packaging box 1.

[0079] The packaging box 1 in this example is for storing agricultural products such as vegetables, and is configured so that it can be easily made into a box by hand in a field, a warehouse, etc. As shown in Fig. 9, in this example, a substantially L-shaped insertion opening 21d is provided in the long flap 21, and an insertion piece 22a that is inserted into this insertion opening 21d is provided in the short flap 22.

[0080] Two insertion openings 21d are provided on each long flap 21, and are configured to open by folding a rocking piece 21e formed by a full cut line at a rocking crease line e and rocking it inward. Also, an orthogonal crease line f that is substantially perpendicular to the rocking crease line e is provided on the rocking piece 21e, and by folding the rocking piece 21e at this orthogonal crease line f, it is possible to make the rocking piece 21e easier to rock.

[0081] The insertion pieces 22a are provided on both sides in the X direction at the tip of the short flap 22, and are configured to have a trapezoidal shape with a narrow tip side. A pressing piece 22b having a trapezoidal shape with a narrow tip side is provided between the two insertion pieces 22a, and a clamping slit 22c consisting of a full cutting line cut so as to extend the side end of the pressing piece 22b is provided on the base end side of the pressing piece 22b.

[0082] Further, a fold line g for inclination that is substantially parallel to the fold line b2 for the short flap is provided at a substantially middle position in the Y direction of the short flap 22. This fold line g for inclination is intended to incline the tip side of the short flap 22 to facilitate insertion of the insertion piece 22a into the insertion port 21d.

[0083] In addition, in this example, the rear end portion of the groove 23 on the bottom plate 1b side is configured into a triangular shape whose width gradually increases toward the rear end, so that both ends or one end of the long flap fold line b1 on the bottom plate 1b side are positioned closer to the center of the long side panel 11 than the end of the additional fold line c on the bottom plate 1b side.

[0084] In this way, the auxiliary fold line d may be omitted as appropriate and a notch or the like may be provided instead to adjust the difficulty of bending the additional fold line c. Note that even in this case, the long side panel 11 is supported by the long flap 21 on the top panel 1a side where the auxiliary fold line d is provided, so that the additional fold line c is prevented from bending unintentionally. Also, in this example, the additional fold line c has a portion located closer to the center of the long side panel 11 than both ends of the long flap fold line b1 on the bottom panel 1b side, so that the long flap 21 on the bottom panel 1b side also prevents the additional fold line c from bending unintentionally.

[0085] In this example, an oval hand hole 16 is provided in the short side panel 12, and an oval or circular ventilation hole 24 is provided in the long flap 21 and the short flap 22. In this example, the seam 15 is extended in the Y direction via the additional flap fold line b3 so that it is also bonded to the short flap 22, and the area where the seam 15 is bonded is a stepped area CA that has been subjected to a stepped processing. In this example, a finger hook 25 cut into a U-shape or semicircular shape is provided at the tip 21a of the long flap 21 and the tip 22d of the short flap 22. The finger hook 25 is provided to facilitate the assembly and disassembly of the packaging box 1.

[0086] 10A and 10B, in this example, the long flap 21 is a so-called inner flap, and the short flap 22 is a so-called outer flap. Therefore, the insertion piece 22a is inserted into the insertion opening 21d when the short flap 22 is folded at the short flap crease line b2 after the long flap 21 is folded at the long flap crease line b1 to form the additional corner 14. By inserting the insertion piece 22a into the insertion opening 21d, the peripheral edge of the insertion opening 21d enters the clamping slit 22c, and the long flap 21 is clamped between the insertion piece 22a and the pressing piece 22b.

[0087] Therefore, in this example, it is possible to maintain the long flap 21 and the short flap 22 in an appropriate overlapping state without using adhesive tape, adhesives, etc. Also, the pressing piece 22b can prevent the long flap 21 from swinging so that the tip 21a moves away from the body 10, so that the bent state of the additional corner 14 can be properly maintained and the body 10 can be maintained in an appropriate shape.

[0088] Fig. 11 and Figs. 12A and B show an example in which an additional crease line c is provided on the short side panel 12, and an engaging portion of the short flap 22 that engages with the long flap 21 receives a force to fold the additional crease line c. Fig. 11 is a development view of the packaging box 1 of this example, and shows the front side of the blank sheet 1x before the packaging box 1 is made. Fig. 12A is a schematic diagram showing the bottom plate 1b side of the cylindrical body 1y in the middle of making the packaging box 1, and Fig. 12B is a schematic diagram showing the bottom plate 1b side of the open box body 1z in the middle of making the packaging box 1.

[0089] 9 and 10A and B, the packaging box 1 of this example has an insertion opening 21d provided in the long flap 21, and an insertion piece 22a, a pressing piece 22b, and a clamping slit 22c provided in the short flap 22. Also, in this example, an edge crease line h is provided for partially folding the edge of the insertion opening 21d to facilitate the insertion of the insertion piece 22a.

[0090] In this example, the short side panel 12 constitutes the first side panel of the present invention, and the short flap 22 constitutes the flap of the present invention. The insertion piece 22a, the pressing piece 22b, and the clamping slit 22c constitute the engagement portion of the present invention. The insertion piece 22a is inserted into the insertion port 21d, and the rear end 22c1 of the clamping slit 22c abuts against the stopper 21d1 provided on the edge of the insertion port 21d, so that the short flap 22 receives a force for folding the additional fold line c. That is, in this example, the rear end 22c1 of the clamping slit 22c constitutes the force receiving portion of the present invention.

[0091] Therefore, in this example, the distance L3 in the Y direction from the short flap fold line b2 to the inner end 22c1 of the clamping slit 22c is set to be greater than the distance L4 in the X direction from the body fold line a on the side where the insertion piece 22a is to be inserted to the stopper 21d1. Also, the distance L1 in the long flap 21 is set to a dimension relative to the distance L2 in the short side plate 12 that does not hinder the deformation of the body 10 when the additional corner 14 is formed.

[0092] In this example, the additional corner 14 is formed by abutting the inner end 22c1 of the clamping slit 22c against the stopper 21d1 as described above. Specifically, as shown in Fig. 12A, after the long flap 21 is folded at the long flap fold line b1, the inclination fold line g is folded to insert the insertion piece 22a into the insertion opening 21d, and the short flap 22 is folded at the short flap fold line b2.

[0093] 12B, even after the inner end 22c1 of the clamping slit 22c abuts against the stopper 21d1, the short flap 22 continues to be folded at the short flap fold line b2, so that the short flap 22 receives a force from the long flap 21, which pushes the short side panel 12 and bends the additional fold line c, forming the additional corner 14. The additional corner 14 is also formed on the top panel 1a side in the same manner as on the bottom panel 1b side.

[0094] When providing the additional fold line c on the short side panel 12, using the tip 22d of the short flap 22 as the force receiving part would increase the material cost, but by providing an engaging part on the short flap 22 that engages with another part of the packaging box 1 and providing a force receiving part on this engaging part, the material cost can be reduced. The engaging part on the short flap 22 may be one that engages with the long side panel 11, for example. Also, it goes without saying that when the additional fold line c is provided on the long side panel 11, an engaging part may be provided on the long flap 21.

[0095] Fig. 13 and Fig. 14A and B show an example in which the closing portion 20, which becomes the bottom plate 1b, is configured with an American lock. Fig. 13 is a development view of the packaging box 1 of this example, and shows the surface of the blank sheet 1x before the packaging box 1 is made. Fig. 14A is a schematic diagram showing the bottom plate 1b side of the cylindrical body 1y in the middle of making the packaging box 1, and Fig. 14B is a schematic diagram showing the bottom plate 1b side of the open box body 1z in the middle of making the packaging box 1.

[0096] The packaging box 1 of this example has substantially the same configuration as the example shown in Figures 1 to 4, except that the long flap 21 and short flap 22 on the bottom plate 1b side are shaped to conform to an American lock. The long flap 21 and short flap 22 on the bottom plate 1b side are each cut into a trapezoidal or rectangular shape to form an engagement portion 26 that engages with each other. The recessed corner portion 26a of the engagement portion 26 provided on the long flap 21 constitutes the force receiving portion of the present invention.

[0097] In this example, because an additional fold line c is provided on the long side panel 11, the distance L1 in the long flap on the top panel 1a side is set to be greater than half the distance L2 in the short side panel 12. On the bottom panel 1b side, the distance L5 in the Y direction from the long flap fold line b1 in the long flap 21 to the recessed corner 26a, and the distance L6 in the X direction from the body fold line a in the short flap 22 to the recessed corner 26a are set to be approximately the same as the distance L1.

[0098] In this example, the additional corner 14 on the bottom plate 1b side is formed by abutting the respective recessed corners 26a of the long flap 21 and the short flap 22. Specifically, as shown in Fig. 14A, the U-shaped long flap 21 is folded along the long flap fold line b1, and then the short flap 22 is folded along the short flap fold line b2, and finally the mountain-shaped long flap 21 is folded along the long flap fold line b1.

[0099] Then, the long flap 21 and the short flap 22 are further folded toward the inside of the packaging box 1 along the long flap fold line b1 and the short flap fold line b2 to position the tip of the mountain-shaped long flap 21 inside the U-shaped long flap 21, and then the long flap 21 and the short flap 22 are folded back to form the closure portion 20.

[0100] 14B, the recessed corner 26a of the mountain-shaped long flap 21 comes into contact with the recessed corner 26a of the U-shaped long flap 21, and the two long flaps 21 are subjected to a force pressing against each other. In addition, the recessed corner 26a of the U-shaped long flap 21 also comes into contact with the recessed corner 26a of the short flap 22, and therefore is subjected to a force from the short flap 22 in approximately the same direction.

[0101] As a result, the long side panel 11 is pushed and the additional fold line c is bent, forming the additional corner 14. Note that on the top panel 1a side, the tips 21a of the long flaps 21 are pushed against each other, forming the additional corner 14. In this way, even when the closure section 20 is configured with an American lock, by appropriately configuring each part of the long flaps 21 and short flaps 22, it is possible to facilitate box making while providing the additional corner 14.

[0102] 15, 16A and 16B, and 17A and 17B show an example in which the closing portion 20, which becomes the bottom plate 1b, is configured from a bottom lock. FIG. 15 is a development view of the packaging box 1 of this example, showing the surface of the blank sheet 1x before the packaging box 1 is made. FIG. 16A and 16B show the procedure for forming the cylindrical body 1y of the packaging box 1, and FIG. 16B shows the state of the inner long flap 21 and short flap 22 by partially cutting out the long side plate 11 and the short side plate 12 on the front side. FIG. 17A shows the positional relationship between the long flap 21 and the short flap 22 when the closing portion 20 is formed. FIG. 17B is a schematic view showing the bottom plate 1b side of the open box body 1z in the middle of making the packaging box 1.

[0103] The packaging box 1 of this example has substantially the same configuration as the example shown in Figures 1 to 4, except that the long flap 21 and short flap 22 on the bottom plate 1b side are shaped to conform to the bottom lock, the short flap 22 on the top plate 1a side is configured in a hexagonal shape, the seam 15 is extended toward the top plate 1a side, and two of the four auxiliary fold lines d on the bottom plate 1b side are provided on the long side plate 11.

[0104] The long flap 21 on the bottom plate 1b side has a triangular cutout at the tip side to form an engaging portion 26 for engaging with each other. The recessed corner 26a of the engaging portion 26 constitutes the force-receiving portion of the present invention. Therefore, the distance L5 in the Y direction from the long flap fold line b1 to the recessed corner 26a of the long flap 21 is set to be approximately the same as the distance L1 of the long flap on the top plate 1a side, and larger than 1 / 2 the distance L2 of the short side plate 12.

[0105] Also, an adhesive part 22g is provided on the surface of the short flap 22 on the bottom plate 1b side for adhering to the long flap 21 on the left side of the figure. A folding crease i for pre-folding a part of the long flap 21 before adhering to the short flap 22 is provided on the long flap 21 on the side of the short flap 22 to be adhered, and an adhesive part 21g is provided on the back side of the folding part 21f defined by the folding crease i.

[0106] In general, the folding crease line i is provided along a straight line that passes through an intersection point j where the body crease line a and the long flap crease line b1 are extended and intersect, and that forms an angle θ of 45° with the flap crease line b1. In contrast, in this example, the folding crease line i is provided along a straight line that does not pass through the intersection point j and that forms an angle θ of approximately 43°, so that the adhesive portion 21g constitutes a force-receiving portion.

[0107] When the closing portion 20 that becomes the bottom plate 1b is composed of a bottom lock, the cylindrical body 1y is formed by folding the long flap 21 and the short flap 22 on the bottom plate 1b side at the long flap crease line b1 and the short flap crease line b2 as shown in Fig. 16A, and folding the folding portion 21f at the folding crease line i as shown in Fig. 16B, folding the long side plate 11 and the short side plate 12 at both ends in the X direction at the body crease line a, and bonding the joint 15 to the short side plate 12 and the short flap 22 on the opposite side. Then, together with bonding the joint 15 to the short side plate 12, the bonding portions 21g and 22g that correspond to each other (adjacent to each other across the body crease line a to be folded) are bonded.

[0108] 16A, in the state where the long flap 21, the short flap 22, and the folding portion 21f are folded, the X-direction distance L7 between the adhesive portions 21g and 22g and the body fold line a near the fold line a to be folded when the tubular body 1y is formed is set to be approximately the same in the adhesive portions 21g and 22g corresponding to each other, and the Y-direction distance L8 between the adhesive portions 21g and 22g and the long flap fold line b1 or the short flap fold line b2 is set to be approximately the same in the adhesive portions 21g and 22g corresponding to each other. As a result, in the formed tubular body 1y, the positions of the adhesive portions 21g and 22g corresponding to each other are aligned, as shown in FIG.

[0109] It can also be said that one of the adhesive parts 21g and 22g is formed by applying adhesive to one of the long flap 21 and the short flap 22, and the other is formed by the adhesive being applied when the long flap 21 and the short flap 22 are adhered to each other. Even in this case, the distances L7 and L8 in the corresponding adhesive parts 21g and 22g are approximately the same.

[0110] The closure portion 20, which is made up of a bottom lock, is formed by folding back the folded long flaps 21 and short flaps 22 while engaging the engaging portions 26 with each other, while forming the rectangular tubular body portion 10. At this time, the folded portion 21f is also folded back.

[0111] When the body 10 is formed into a rectangular tube shape and the closing portion 20 is formed, the posture of the short flaps 22 relative to the long flaps 21 changes as shown in Fig. 17A, but the distance L7 from the body fold line a and the distance L8 from the short flap fold line b2 of the adhesive portion 22g are maintained. Meanwhile, the adhesive portion 21g moves from the position in the folded state of the folding portion 21f (the position shown by the two-dot chain line in the figure) to a position that is symmetrical with respect to the folding fold line i as the folding portion 21f is folded back.

[0112] In a normal bottom lock, the folding crease line i is set along a straight line that passes through the intersection j at an angle θ of 45°, so that the adhesive part 21g after folding back the folding part 21f moves to the same position as the adhesive part 22g, but in this example, the folding crease line i is set along a straight line that does not pass through the intersection j at an angle θ of about 43°, so that the position of the adhesive part 21g after folding back the folding part 21f is shifted from the position of the adhesive part 22g. This position shift of the adhesive part 21g causes the long flap 21 to receive a force from the short flap 22.

[0113] 17B, ​​the long side panel 11 is pushed and the additional fold line c is bent, forming the additional corner 14, due to the force that the adhesive portion 21g receives from the short flaps 22 and the force of the recessed corners 26a pushing against each other. Note that on the top panel 1a side, the tips 21a of the long flaps 21 push against each other, forming the additional corner 14. In this way, even when the closure portion 20 is configured with a bottom lock, by appropriately configuring each part of the long flaps 21 and short flaps 22, it is possible to facilitate box making while providing the additional corner 14.

[0114] The folding crease line i may be along a straight line passing through the intersection j if the angle θ is not 45°, or may be along a straight line not passing through the intersection j even if the angle θ is 45°. In either case, the position of the adhesive portion 21g after folding back the folded portion 21f can be shifted from the position of the adhesive portion 22g. The folding crease line i may be composed of a pressed crease line, a half-cut line, or the like.

[0115] Although the embodiment of the present invention has been described above, the packaging box of the present invention is not limited to the above-mentioned embodiment, and various modifications can be made within the scope of the present invention. For example, the type of the packaging box is not limited to the so-called Type A, and may be other types such as the so-called Type B. In addition, the material of the packaging box is not particularly limited, and may be various types of cardboard other than double-sided cardboard, thick paper, various types of resin cardboard, resin board, etc. In addition, it goes without saying that the posture of the packaging box 1 is not particularly limited.

[0116] Furthermore, the actions and effects shown in the above-described embodiments are merely a list of the most preferable actions and effects resulting from the present invention, and the actions and effects of the present invention are not limited to these. [Explanation of symbols]

[0117] 1 packaging box 10. Torso 10a open end 11 Long side plate 12 Short side plate 20 Occlusion 21 Long flap 21a Tip of long flap 21g Long flap adhesive 22 Short flap 22a Insert 22b Clamp 22c Clamping slit 22c1 Back end of clamping slit 26 Engagement part 26a Recessed corner a Body fold line b1 Long flap fold line b2 Short flap fold line c Additional crease line

Claims

1. A packaging box having a cylindrical body and a closing part that closes one of two open ends of the body, the body portion has a pair of first side plates facing each other, and a pair of second side plates connected to the pair of first side plates via body fold lines to connect the pair of first side plates, The closing portion has a flap that is connected to the first side panel via a flap fold line and is folded inward at the flap fold line, At least one of the pair of first side plates is provided with an additional fold line extending in the same direction as the body fold line, The flap has a force receiving portion that receives a force from another portion of the packaging box in accordance with a change in the relative position or relative posture of each portion of the packaging box during a box-making procedure, The packaging box is characterized in that the additional fold line is folded when the force receiving portion receives a force.

2. The packaging box according to claim 1, The closing portion has a pair of flaps whose tips abut against each other, The packaging box is characterized in that the force receiving portion is provided at the tip of the flap.

3. The packaging box according to claim 1, The flap has an engagement portion that engages with another portion of the packaging box, The packaging box according to claim 1, wherein the force receiving portion is provided on the engagement portion.

4. The packaging box according to claim 1, The flap has an adhesive portion that is adhered to another portion of the packaging box, The packaging box is characterized in that the force-receiving portion is composed of the adhesive portion.

5. The packaging box according to claim 1, A packaging box, wherein the additional fold line has a portion that is not parallel to the body fold line.

6. The packaging box according to claim 1, The packaging box is characterized in that the additional fold line is provided along a line that protrudes toward the center of the first side panel.

7. The packaging box according to claim 1, The packaging box according to claim 1, wherein the additional fold line has a portion located closer to the center of the first side panel than both ends of the flap fold line.

Images