JP7382693B2 - Folding lock structure of packaging box - Google Patents

Description

The present invention relates to a technique for improving the stackability of discarded packaging boxes by maintaining them in a folded state.

Conventionally, for example, as shown in Patent Document 1, when a packaging box made of thick paper such as used cardboard is folded, the folded state is maintained to reduce the bulk and improve the stackability. The technology is known.

In Patent Document 1, in a packaging box consisting of a rectangular cylindrical main body formed by four body panels and a flap that seals the opening surface of the main body, adjacent body panels with ruled lines in between are Two cutting lines or easy-to-cut lines are cut across the ruled line, and between the cutting lines or easy-to-cut lines, folding lock pieces are formed facing each other with the ruled line in between, and A configuration is disclosed in which a cutting line or an easy-to-cut line that partitions one or both of the opposing edges of the folding lock pieces is cut at a position offset with respect to the ruled line.

Patent No. 4715050 specification

In the configuration of Patent Document 1, when the packaging box is dismantled for disposal, the flap is first opened to form a cylindrical state, then folded along the two ruled lines, and then locked by folding the lock piece. It is something that

However, when the direction of the cylindrical axis of the cylinder is defined as the depth direction, and the direction perpendicular to the depth direction is defined as the width direction, the lock pieces are located at both ends in the width direction.

For this reason, the body panels located in the center of the width and facing each other are not particularly locked together, and a gap remains, making it difficult to tie multiple packaging boxes together with string. Instead, when disposing of the packaging box individually, the widthwise center of the packaging box tends to open, making handling inconvenient.

In view of the above-mentioned problems, the present invention proposes a packaging box with a novel configuration that is easy to handle even as a single unit and has excellent stackability by locking body panels that face each other in a folded state. It is something.

The problem to be solved by the present invention is as described above, and next, means for solving this problem will be explained.

According to one aspect of the invention,
A folding lock structure of a packaging box for locking body panels facing each other in a folded state,
A pair of lock pieces are formed in the plane of each of the body panels to face each other in a folded state,
One lock piece is raised in the direction away from the other lock piece to form a through hole,
The other lock piece is inserted into the formed through hole and locked in the through hole.
The packaging box has a folding lock structure.

Further, according to one aspect of the present invention,
It is assumed that two pairs of lock pieces are provided, and each pair is arranged at a position close to both ends in the long side direction of each body panel.

Further, according to one aspect of the present invention,
The body panel includes a front plate, a rear plate facing the front plate, and a first side plate and a second side plate, each forming a side surface. , the first side plate part, the rear plate part, and the second side plate part are arranged in this order, and the front plate part and the lock pieces provided on the rear plate portion are opposed to each other.

According to the configuration of the present invention, since the locking piece is locked within the plane of the body panel, the body panels can be engaged with each other at the widthwise central portion of the folded packaging box. The occurrence of a gap in the center can be suppressed, and it is possible to prevent the bag from opening easily and making it inconvenient to handle.

In addition, the folded state can be maintained more reliably since it is locked at two locations in the long side direction.

Furthermore, it is possible to fold the device in two, and in the folded state, the lock piece can be placed in the center portion in the lateral direction.

(A) is a perspective view of the appearance of the packaging box according to Example 1, and (B) is a perspective view of the packaging box according to Example 1 in a usage state. 3 is a developed view of a packaging box according to Example 1. FIG. (A) is a diagram illustrating a portion of the opening lid, and (B) is a diagram illustrating a state in which the opening lid is opened. It is a figure explaining the structure which fixes an opening lid. (A) is a perspective view of the appearance of a packaging box according to Example 2, and (B) is a perspective view of the packaging box according to Example 2 in a usage state. FIG. 3 is a developed view of a packaging box according to Example 2. (A) is a diagram illustrating a portion of the opening lid, and (B) is a diagram illustrating a state in which the opening lid is opened. It is a figure explaining the structure which fixes an opening lid. It is a figure explaining the structure of a thin part. It is a figure explaining the structure of a lock piece. It is a figure explaining the state where a packaging box is folded. (A) is a diagram illustrating a locked state, and (B) is a diagram illustrating a state in which (A) is viewed from an angle.

Embodiments of the present invention will be described below using examples.

FIG. 1(A) is a perspective view of the appearance of the packaging box 2 according to the first embodiment, and FIG. 1(B) is a perspective view of the packaging box 2 according to the first embodiment in a usage state. FIG. 2 is a developed view of the packaging box 2 according to the first embodiment. FIG. 3(A) is a diagram illustrating a portion of the opening lid 40, and FIG. 3(B) is a diagram illustrating a state in which the opening lid 40 is opened. FIG. 4 is a diagram illustrating a structure for fixing the opening lid 40. As shown in FIG. In the following description, for convenience, the vertical direction of the paper surface in FIG. 2 will be referred to as the vertical direction or the height direction, and the horizontal direction of the paper surface will be described as the left-right direction, horizontal direction, or lateral direction.

As shown in FIGS. 1(A) and 1(B), the packaging box 2 is configured in the shape of a rectangular parallelepiped, and accommodates a plurality of PET bottles 3, which are beverage containers. The front plate part 11, which is the front side of the packaging box 2, is provided with an opening lid 40 defined by breaking a cut line (perforation), and the opening lid 40 can be flipped up. In this case, an outlet 50 is formed.

FIG. 2 shows a blank corresponding to the unfolded packaging box 2. This blank is made of a corrugated cardboard sheet, and includes a front plate part 11 that is on the front side in use, and a rear plate part opposite to the front plate part 11. 12, and side plate portions 13 and 14, each forming a side surface. A passage 15 is continuously provided on the outer edge of one side plate portion 14 . Furthermore, flaps 11a, 11b, 12a, . . . are provided in succession on both ends of each plate portion in the longitudinal direction.

As shown in FIGS. 2 and 3(A), a score line 4 for forming an opening lid 40 is continuously provided on one longitudinal end of the front plate portion 11 and on the flap 11a. . The score lines 4 are defined by vertical lines 4a and 4b (FIG. 3A) that extend vertically at intervals in the horizontal direction within the front plate portion 11, and from the lower end of each vertical line 4a and 4b into the flap 11a. It has curved lines 4c and 4d (FIG. 3A) that curve toward each other and a horizontal line 4e (FIG. 2) that connects the lower ends of the curved lines 4c and 4d within the flap 11a.

As shown in FIGS. 2 and 3A, the upper ends of the vertical lines 4a and 4b are connected by a ruled line 5a, which is a valley fold line. Furthermore, a ruled line 5b exists between the front plate portion 11 and the flap 11a, and a score line 4 (curved line 4c, 4d (FIG. 3(A))) is formed so as to straddle this ruled line 5b.

By breaking the cut line 4 configured as described above, the opening lid 40 as shown in FIG. 4 is formed, and by folding it along the ruled line 5a and flipping it up, the outlet 50 is formed.

As shown in FIG. 4, a locking hole 11m into which the locking piece 40a of the opening lid 40 is inserted is provided in the front plate portion 11 at a position above the ruled line 5a. As shown in FIG. 3(A), this locking hole 11m breaks the horizontal cut line 6a provided in the front plate part 11 and the diagonal cut lines 6b, 6b at both ends thereof, and The opening is made by mountain-folding the paper 6a along a parallel line 6c below the paper 6a.

As shown in FIGS. 2 and 4, the locking piece 40a of the opening lid 40 is a part that existed on the flap 11a, and is a part that is bent along the ruled line 5b.

As described above, as shown in FIG. 4, a fixing structure is formed by the locking piece 40a of the opening lid 40 and the locking hole 11m, and the opening lid 40 is flipped up to lock the locking piece 40a. When inserted into the hole 11m, the opening lid 40 can be kept open as shown in FIG. 3(B).

By maintaining the opening lid 40 in an open state in this way, the opening lid 40 is not opened halfway and a troublesome situation such as holding the opening lid 40 by hand can be avoided. It is possible to always easily take out the plastic bottle 3 that is being stored.

In addition, by flipping up the opening lid 40, the opening lid 40 can be stored along the front plate portion 11, and the opening lid 40 will not become half-open and become a hindrance.

If the opening lid 40 were to be lowered toward the front, the opening lid 40 would protrude to the front of the packaging box 2 and become a hindrance, but since it can be flipped up as described above, It doesn't get in the way. Furthermore, even when the opening lid 40 is opened and the PET bottle 3 is arbitrarily taken out from the packaging box 2, the opening lid 40 does not protrude, increasing the flexibility of the installation space and allowing for a space-saving configuration. realizable.

FIG. 5(A) is a perspective view of the appearance of the packaging box 2 according to the second embodiment, and FIG. 5(B) is a perspective view of the packaging box 2 according to the second embodiment in a usage state. FIG. 6 is a developed view of the packaging box 2 according to the second embodiment. FIG. 7(A) is a diagram illustrating a portion of the opening lid 40, and FIG. 7(B) is a diagram illustrating a state in which the opening lid 40 is opened. FIG. 8 is a diagram illustrating a structure for fixing the opening lid 40. As shown in FIG. In the following description, for convenience, the vertical direction of the paper surface in FIG. 5 will be referred to as the vertical direction or the height direction, and the horizontal direction of the paper surface will be described as the left-right direction, horizontal direction, or lateral direction.

As shown in FIGS. 5A and 5B, the packaging box 20 has a rectangular parallelepiped box shape, and accommodates a plurality of PET bottles 3, which are beverage containers. The front plate part 21, which is the front side of the packaging box 20, is provided with an opening lid 60 defined by breaking a cut line (perforation), and the opening lid 60 can be flipped up. In this case, an outlet 70 is formed.

FIG. 6 shows a blank corresponding to the unfolded packaging box 20. This blank is made of a corrugated cardboard sheet, and includes a front plate part 21 which becomes the front side in the use state, and a rear plate part facing the front plate part 21. 22, and side plate portions 23 and 24, each forming a side surface. A passage 25 is continuously provided on the outer edge of one side plate portion 24 . Moreover, flaps 21a, 21b, 22a, . . . are provided in succession on both ends of each plate portion in the longitudinal direction.

As shown in FIGS. 6 and 7(A), a score line 64 for forming an opening lid 60 is continuously provided at one longitudinal end of the front plate portion 21. As shown in FIGS. As shown in FIG. 7(A), the score line 64 is formed by forming vertical lines 64a and 64b that extend vertically at intervals in the horizontal direction within the front plate portion 21, and mutually starting from the lower end of each vertical line 64a and 64b. Diagonal lines 64c and 64d that spread diagonally downward, horizontal lines 64e and 64f that spread toward each other from the lower ends of diagonal lines 64c and 64d, and a horizontal line 64g that connects the lower ends of horizontal lines 64e and 64f. have

As shown in FIGS. 6 and 7(A), the upper ends of the vertical lines 64a and 64b are connected by a ruled line 25a, which is a valley fold line. Furthermore, arc-shaped ruled lines 25b and 25c are formed between the lower ends of the vertical lines 64a and 64b and both ends of the horizontal line 64g.

By breaking the cut line 64 configured as described above, the opening lid 60 as shown in FIG. 8 is formed, and by folding it along the ruled line 25a and flipping it up, the outlet 70 is formed.

As shown in FIG. 8, locking holes 21m and 21n for inserting locking pieces 60a and 60b of the opening lid 60 are provided at positions above the ruled line 25a in the front plate portion 21 with an interval in the lateral direction. provided. Each locking hole 21m, 21n has a substantially V-shaped ruled line 26a provided on the front plate part 21, an arc-shaped score line 26b connecting both ends of the ruled line 26a, and a V-shape of the ruled line 26a from the center of the score line 26b. It has a straight cut line 26c extending to the corner of the character. When the cut lines 26b and 26c are cut, a pair of locking pieces 27 and 27 are formed, and locking holes 21m and 21n are opened. In addition, in FIG. 8, the locking hole 21m on the left side is in an open state, and the locking hole 21n on the right side is shown in an open state.

As shown in FIG. 8, the locking pieces 60a and 60b of the opening lid 60 are parts that are bent along ruled lines 65b and 65c.

As described above, as shown in FIG. 8, a fixing structure is formed by the locking pieces 60a, 60b of the opening lid 60 and the locking holes 21m, 21n, and the locking pieces 60a, 60b of the opening lid 60 are flipped up. When 60a and 60b are inserted into the locking holes 21m and 21n, the opening lid 60 can be kept open as shown in FIG. 7(B).

Furthermore, by inserting the locking pieces 60a, 60b into the locking holes 21m, 21n and placing them on the back side of the locking pieces 27, 27, the locking pieces 60a, 60b can be held down by the locking pieces 27, 27 from the outside. This prevents the locking pieces 60a, 60b from being pulled out from the locking holes 21m, 21n.

With the above configuration, it is possible to realize the packaging box 20 in the second embodiment as well, which has the same effects as in the first embodiment.

Next, a configuration related to improving the ease of taking out the container will be described.
As shown in FIG. 2, when the packaging box 2 is used in an upright position, the flaps 13a and 14a that form the bottom are constructed of thinner parts 13c and 14c, where the portions closer to the outlet 50 are thinner. There is.

As shown in FIG. 9, since the side closer to the outlet 50 is configured with a thin portion 13c having a smaller thickness, a step 13e is formed between the thin portion 13c and the thick portion 13d. Note that the method for forming the thinner portion 13c is not particularly limited, and for example, by pressing the flaps 13a and 14a of the blank packaging box 2 with a roller or a press, the thinner portion 13c may be formed more than other portions. It is possible to reduce the thickness.

By forming this step 13e, the plastic bottle 3 is guided to fall toward the thinner portion 13c, and can be moved to the side closer to the outlet 50.

Further, the plastic bottle 3 that has been moved once does not return to the corner 2s of the packaging box 2 due to the step 13e, and remains on the side closer to the outlet 50.

As described above, by guiding the PET bottle 3 to the outlet 50 without letting it stay in the corner 2s of the packaging box, it is possible to prevent the PET bottle 3 from remaining in the corner 2s and becoming difficult to take out. It is possible to prevent this and achieve excellent retrieval performance.

In order to realize the above, for example, the distance W from the step 13e (starting part 13m of the step) to the corner 2s of the packaging box 2 must be 2/3 or more of the radius R of the plastic bottle 3. , the radius R or less. By making the radius R or less, the PET bottle 3, which is no longer supported from the side when another PET bottle is taken out, can be immediately moved to the thin portion 13c by its own weight. Further, by setting the radius R to ⅔ or more, it is possible to restrict the PET bottle 3 once moved to the thin portion 13c from moving only to the distance W position from the corner portion 2s.

Next, a configuration for locking the body panels facing each other in the folded state will be described.
FIG. 10 is a diagram illustrating the structure of the lock piece. FIG. 11 is a diagram illustrating the folded state of the packaging box. FIG. 12(A) is a diagram illustrating a locked state, and FIG. 12(B) is a diagram illustrating a state viewed diagonally from FIG. 12(A).

As shown in FIG. 2, in this embodiment, the blank includes a front plate part 11 which becomes the front side in the use state, a rear plate part 12 which faces the front plate part 11, side plate parts 13 which constitute the side surfaces, respectively. 14, and each of these plate portions functions as a body panel.

A pair of locking pieces 81 and 82 are provided on the front plate part 11 and the rear plate part 12 at positions facing each other when the packaging box 2 is folded. In this embodiment, two sets of lock pieces, that is, sets of lock pieces 81 and 82 and lock pieces 83 and 84 are arranged with their positions shifted in the vertical direction, and are assumed to be locked at two locations. There is.

As shown in FIG. 2, each lock piece 81, 82 is arranged within the plane of the front plate part 11 and the rear plate part 12, that is, the lock pieces 81, 82 are arranged in the plane of the front plate part 11 and the rear plate part 12. , the flaps 11a, 11b, 12a..., the ruled lines (9a, 9b...) that form the boundary with the passage 15, and even the front plate part 11 and the rear plate without straddling the outer peripheral edge 9z. It is arranged inside the surface of the section 12.

As shown in FIG. 10, the lock piece 81 provided on the front plate part 11 has a crosscut line 81a extending in the horizontal direction, and diagonal cut lines 81b and 81c extending diagonally upward and away from each other from both ends of the crosscut line 81a. and a ruled line 81d extending in the horizontal direction so as to connect the upper ends of the diagonal score lines 81b and 81c. It is configured.

As shown in FIG. 10, the lock piece 82 provided on the rear plate part 12 has a crosscut line 82a extending in the horizontal direction, and diagonal cut lines 82b and 82c extending diagonally downward from both ends of the crosscut line 82a toward each other. and a ruled line 82d extending in the horizontal direction so as to connect the lower ends of the diagonal cut lines 82b and 82c. It is configured.

Then, as shown in FIG. 11, the used packaging box 2 is disassembled and folded so that the front plate part 11 and the rear plate part 12 overlap, and first, as shown in FIGS. 12(A) and (B), , the lock piece 82 is bent and raised to form a through hole 82k. Next, while bending the lock piece 81 so as to insert it into the through hole 82k, the tip of the lock piece 81 is made to protrude from the through hole 82k.

In this way, the lock piece 81 is pressed and locked against the edge of the through hole 82k, preventing the lock piece 81 from being pulled out from the through hole 82k, and causing the front plate part 11 and the rear plate part 12 to overlap. The current state is maintained.

Note that the lock piece 83 shown in FIG. 10 is the lock piece 81 upside down, and the lock piece 84 is the lock piece 82 upside down. The set of lock pieces 83 and 84 also has the same configuration as the set of lock pieces 81 and 82, and performs the same function, so a description thereof will be omitted.

The present invention can be realized as described above.
That is, as shown in FIGS. 1 to 4,
A beverage container packaging box 2 in which an opening 50 is formed in a front plate part 11 by opening an opening lid 40 formed by breaking a score line 4,
The opening lid 40 is opened by flipping up.
has a fixing structure for fixing the opening lid 40 in an open state;
This is a beverage container packaging box 2.

As a result, the opening lid 40 is maintained in an open state, so that the opening lid 40 is not opened halfway and a troublesome situation such as holding the opening lid 40 by hand can be avoided. It is possible to always easily take out the plastic bottle 3 that is being stored.

In addition, as shown in FIGS. 1 to 4,
The fixing structure includes a locking piece 40a provided on the opening lid 40,
11 m of locking holes provided in the front plate part 11 in which the outlet is formed;
It shall consist of:

Thereby, the present invention can be realized with a simple configuration.

Moreover, as shown in FIGS. 5 to 8,
The fixing structure includes locking pieces 60a and 60b provided at two laterally separated locations on the opening lid 60;
Locking holes 21m and 21n provided at two locations on the front plate portion 21 where the outlet is formed;
It shall consist of:

Thereby, the opening lid 60 can be securely fixed at two locations.

Further, as shown in FIGS. 1(A) and 1(B), the beverage container packaging box 2 is installed vertically so that the PET bottle 3 serving as the beverage container is laid down on its side, and the outlet 50 is located at the lower part of the front plate portion 11. The beverage container is taken out by being pulled out laterally.

Thereby, the opening lid 40 can be housed along the front plate part 11, and the opening lid 40 will not be half-open and become a hindrance. If the opening lid 40 were to be lowered toward the front, the opening lid 40 would protrude to the front of the packaging box 2 and get in the way, but since it can be flipped up as described above, it does not get in the way at all. It never becomes. Furthermore, even when the opening lid 40 is opened and the PET bottle 3 is arbitrarily taken out from the packaging box 2, the opening lid 40 does not protrude, increasing the flexibility of the installation space and allowing for a space-saving configuration. realizable.

Further, as shown in FIGS. 2 and 9, the outlet 50 is formed at the center in the left-right direction of the beverage container packaging box 2 in the use state, and the inner bottom surface of the beverage container packaging box 2 is It is composed of flaps 13a and 14a extending from the corners 2s of the left and right ends of the beverage container packaging box 2 toward the outlet 50, respectively, and a thinner part 13c is provided on the side of the flaps 13a and 14a closer to the outlet 50. It is intended to be established.

Thereby, by guiding the PET bottle 3 to the outlet 50 without having it remain in the corner 2s of the packaging box, it is possible to prevent the PET bottle 3 from remaining in the corner 2s and becoming difficult to take out. It is possible to achieve excellent retrieval performance.

Moreover, as shown in FIGS. 2 and 11,
A folding lock structure of a packaging box 2 for locking body panels (front plate part 11 and rear plate part 12) facing each other in a folded state,
A pair of lock pieces 81 and 82 are formed in the plane of each body panel (front plate part 11 and rear plate part 12), respectively, so as to face each other in the folded state.
One lock piece 82 is raised in a direction away from the other lock piece 81 to form a through hole 82k,
The other lock piece 81 is inserted into the formed through hole 82k and is locked in the through hole 82k.
The structure is as follows.

In this configuration, since the locking pieces 81 and 82 are locked within the plane of the body panel, the body panels can be engaged with each other at the widthwise central portion of the packaging box 2 in the folded state. The occurrence of a gap in the center can be suppressed, and it is possible to prevent the bag from opening easily and making it inconvenient to handle. After folding, it can be easily handled and stacked as a single unit.

Moreover, as shown in FIGS. 2 and 11,
Two sets of the pair of lock pieces 81 and 82 are provided, and each set is arranged at a position close to both ends in the long side direction of each body panel (front plate part 11 and rear plate part 12). It is something to do.

As a result, it is locked at two locations in the long side direction, making it possible to maintain the folded state more reliably.

Further, as shown in FIG. 2, the body panel includes a front plate part 11, a rear plate part 12 facing the front plate part 11, and a first side plate part 13 and a second side plate part forming side surfaces, respectively. 14, and are arranged in this order: the front plate part 11, the first side plate part 13, the rear plate part 12, and the second side plate part 14. By bending the plate part 12 along the ruled line 9b at the boundary, the lock pieces 81 and 82 provided on the front plate part 11 and the rear plate part 12, respectively, are configured to face each other.

This makes it possible to fold it in two, and in the folded state, the locking pieces 81 and 82 can be arranged at the center in the lateral direction.

2 Packaging box 3 PET bottle 9b Ruled line 11 Front plate part 12 Back plate part 13 Side plate part 14 Side plate part 15 Passage 81 Lock piece 82 Lock piece 81a Cross cut line 81b Diagonal cut line 81c Diagonal cut line 81d Ruled line 82 Lock piece 82a Horizontal Score line 82b Diagonal score line 82c Diagonal score line 82d Ruled line 82k Through hole

Claims (2)

A folding lock structure of a packaging box for locking body panels facing each other in a folded state,
The body panel includes a front plate part, a rear plate part facing the front plate part, and a first side plate part and a second side plate part facing each other,
A pair of lock pieces are formed in the planes of the front plate part and the rear plate part, respectively, so as to face each other in a folded state,
One lock piece is raised in the direction away from the other lock piece to form a through hole,
The other lock piece is inserted into the formed through hole and locked in the through hole,
H-shaped cut lines are formed in the first side plate part and the second side plate part, and the front plate part, the rear plate part, the first side plate part, and the second side plate part are formed with an H-shaped cut line. By providing flaps on the side panels and, the packaging box is configured in a wrap-around format.
By bending and folding along the ruled line of the boundary between the first side plate part and the rear plate part, the lock pieces provided on the front plate part and the rear plate part respectively face each other,
One lock piece is arranged horizontally so as to connect a transverse line extending in the horizontal direction, a pair of diagonal cut lines extending diagonally downward from both ends of the cross line toward each other, and the lower ends of the pair of diagonal cut lines. Surrounded by a ruled line extending to
It is configured in a trapezoidal shape where the cross-grain lines are longer than the ruled lines,
The other lock piece is arranged horizontally so as to connect a transverse line extending in the horizontal direction, a pair of diagonal cut lines extending diagonally upward and away from each other from both ends of the cross line, and the upper ends of the pair of diagonal cut lines. It is configured in a trapezoidal shape, surrounded by ruled lines that extend into
One lock piece and the other lock piece are formed so that each other has a trapezoid upside down,
An edge portion is formed by cutting a wide cross-grain line portion in the through hole formed by one lock piece, and the wide ruled line side portion of the other lock piece engages with the edge portion. be stopped,
Folding lock structure of packaging box. A folding lock structure of a packaging box for locking body panels facing each other in a folded state,
The body panel includes a front plate part, a rear plate part facing the front plate part, and a first side plate part and a second side plate part facing each other,
A pair of lock pieces are formed in the planes of the front plate part and the rear plate part, respectively, so as to face each other in a folded state,
One lock piece is raised in the direction away from the other lock piece to form a through hole,
The other lock piece is inserted into the formed through hole and locked in the through hole,
H-shaped cut lines are formed in the first side plate part and the second side plate part, and the front plate part, the rear plate part, the first side plate part, and the second side plate part are formed with an H-shaped cut line. By providing flaps on the side panels and, the packaging box is configured in a wrap-around format.
Two pairs of locking pieces are provided, each pair being arranged at a position close to both ends in the longitudinal direction of the front plate part and the rear plate part, respectively ,
By bending and folding along the ruled line of the boundary between the first side plate part and the rear plate part, the lock pieces provided on the front plate part and the rear plate part respectively face each other,
One lock piece is arranged horizontally so as to connect a transverse line extending in the horizontal direction, a pair of diagonal cut lines extending diagonally downward from both ends of the cross line toward each other, and the lower ends of the pair of diagonal cut lines. Surrounded by a ruled line extending to
It is configured in a trapezoidal shape where the cross-grain lines are longer than the ruled lines,
The other lock piece is arranged horizontally so as to connect a transverse line extending in the horizontal direction, a pair of diagonal cut lines extending diagonally upward and away from each other from both ends of the cross line, and the upper ends of the pair of diagonal cut lines. It is configured in a trapezoidal shape, surrounded by ruled lines that extend into
One lock piece and the other lock piece are formed so that each other has a trapezoid upside down,
An edge portion is formed by cutting a wide cross-grain line portion in the through hole formed by one lock piece, and the wide ruled line side portion of the other lock piece engages with the edge portion. The folding lock structure of the packaging box.