Packaging box

Abstract

To provide a packaging box that can be folded compactly.SOLUTION: A box body 3 of a packaging box is deformed between a folded form and an assembled form. The box body 3 includes: a pair of first side walls 11 connected to both ends of a bottom wall 10 in a front-rear direction via a first lower fold line 21A; and a pair of second side walls 12 connected to both ends of the bottom wall 10 in a left-right direction via a second lower fold line 22A, wherein the first side wall 11 has a first upper fold line 21B formed parallel to the first lower fold line 21A with a first interval 27, the second side wall 12 has a second upper fold line 22B formed parallel to the second lower fold line 22A at a second interval 28 wider than the first interval 27, and when the box body 3 is folded, the first side wall 11 is folded inward along the first fold line 21 and is laminated on the bottom wall 10, and the second side wall 12 is folded inward along the second fold line 22 and is laminated on the bottom wall 10 with the first side wall 11 interposed therebetween.SELECTED DRAWING: Figure 2

Description

[Technical field]

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

[0002] For example, a packaging box is known in which both side surfaces, the front surface, and the back surface are each connected to the four sides of the bottom surface via a single fold line (Patent Document 1). Such a packaging box is distributed in an unfolded state in which both side surfaces, the front surface, and the back surface are flush with the bottom surface, and is assembled when the packaged item is to be housed. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2004-196401 A Summary of the Invention [Problem to be solved by the invention]

[0004] The above-mentioned packaging box occupies a very large area when unfolded, which makes it difficult to secure storage space and transport. If the packaging box could be folded compactly by folding both sides, the front and the back side approximately 180 degrees so that they overlap on the bottom, the above-mentioned problem could be solved. However, when the side or the like is folded 180 degrees along a single fold line, a tear occurs along the fold line on the outer surface of the side or the like due to bending stress (folding load), or the side or the like opens up due to the repulsive force around the fold line. In other words, the above-mentioned packaging box could not be folded compactly due to its structure.

[0005] In consideration of the above circumstances, the present invention provides a packaging box that can be folded compactly. [Means for solving the problem]

[0006] The present invention provides a packaging box including a box body that can be transformed between a folded state in which the box body is folded flat and an assembled state in which an object can be stored, the box body including a bottom wall formed in a polygonal shape having at least four sides, a pair of first side walls that are connected to both ends of the bottom wall in a first direction via a first lower fold line, and a pair of second side walls that are connected to both ends of the bottom wall in a second direction perpendicular to the first direction via a second lower fold line, the first side walls having a first upper fold line that is formed parallel to the first lower fold line at a first interval, The second side wall has a second upper fold line formed parallel to the second lower fold line at a second interval wider than the first interval, and when the box body is in the folded form, the first side wall is folded inwardly along the first lower fold line and the first upper fold line to be stacked on the bottom wall, and the second side wall is folded inwardly along the second lower fold line and the second upper fold line to be stacked on the bottom wall with the first side wall in between, and when the box body is in the assembled form, the first side wall and the second side wall are erected relative to the bottom wall.

[0007] In this case, the box body further includes two pairs of inner folding pieces connected to both ends in the second direction of the pair of first side walls excluding the first gap via one-sided fold lines, and at least one pair of folding pieces connected to at least one of the pair of first side walls or to two inner folding pieces located diagonally between at least the pair of first side walls via an inclined fold line formed diagonally so as to cut lower corners of the inner folding pieces, the folding pieces being formed to protrude downward and fill the first gap, and when the box body is folded into the folded form, the folding pieces are folded inward along the inclined fold line and stacked on the inner surface of the inner folding piece, and the inner folding piece is folded inward along the one-sided fold line. and stacked on the inner surface of the first side wall, the first side wall is stacked on the bottom wall with the inner folding piece sandwiched therebetween, and the second side wall is stacked on the bottom wall with the first side wall sandwiched therebetween; when the box body is put into the assembled form, the folding pieces folded at the inclined fold line are returned, a pair of the first side walls are erected at both ends of the bottom wall in the first direction, and two pairs of the inner folding pieces extend from both ends of the pair of first side walls in the second direction toward a center in the first direction and are connected at a center part in the first direction and erected at both ends of the bottom wall in the second direction, so that lower ends of the folding pieces are pressed against the bottom wall to push up the pair of first side walls, and the pair of second side walls are erected to cover outer surfaces of the two pairs of the inner folding pieces.

[0008] In this case, the pair of folding pieces are connected to a pair of the inner folding pieces connected to one of the pair of first side walls, or to two of the inner folding pieces located diagonally between the pair of first side walls, a lower interlocking groove cut from above to below is formed in the folding piece, and an upper interlocking groove cut from below to above is formed in the other inner folding piece opposite the folding piece, and in the process of bringing the box body into the assembled form, when the two pairs of the inner folding pieces are connected at the center in the first direction, the lower interlocking groove of the pair of the folding pieces and the upper interlocking groove of the pair of the inner folding pieces interlock with each other.

[0009] In this case, the box body further includes a pair of fold pieces connected to the upper ends of the pair of second side walls via fold lines, and in the process of putting the box body into the assembled form, the pair of second side walls are erected so as to cover the outer surfaces of the two pairs of inner fold pieces, and the pair of fold pieces are folded inwardly along the fold lines while pulling up the pair of second side walls, and are fixed in a state in which the two pairs of inner fold pieces are sandwiched between the pair of second side walls.

[0010] In this case, when the box body is in the assembled form, it is provided with a lid body that opens and closes a top opening surrounded by the upper edges of a pair of the first side walls and a pair of the second side walls, and the lid body has a top wall formed in a polygonal shape that can close the top opening, and a tubular lid portion that hangs downward from the peripheral edge of the top wall, and the box body in the folded form is accommodated in the area surrounded by the top wall and the tubular lid portion. Effect of the Invention

[0011] According to the present invention, the packaging box can be folded compactly. [Brief description of the drawings]

[0012] [Figure 1] 1 is a perspective view showing a packaging box according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a plan view showing a blank for a box body of a packaging box according to one embodiment of the present invention. [Diagram 3] FIG. 2 is a plan view showing a blank for a lid body of a packaging box according to one embodiment of the present invention. [Figure 4] 1 is a perspective view showing a state in which a folding piece of a box body of a packaging box according to one embodiment of the present invention is folded back. FIG. [Diagram 5] 1 is a perspective view showing a state in which an inner folding piece of a box body of a packaging box according to one embodiment of the present invention is folded back. FIG. [Figure 6] 1 is a perspective view showing a state in which a front first side wall of a box body of a packaging box according to one embodiment of the present invention is folded back. [Figure 7]1 is a perspective view showing a state in which a pair of first side walls of a box body of a packaging box according to one embodiment of the present invention are folded back. FIG. [Figure 8] 1 is a perspective view showing a state in which a second left side wall of a box body of a packaging box according to one embodiment of the present invention is folded back. FIG. [Figure 9] 1 is a perspective view of a packaging box according to an embodiment of the present invention, showing a box body in a folded state. [Figure 10] 1 is a perspective view of a packaging box according to an embodiment of the present invention, showing a state in which a box body in a folded form is housed in a lid body. [Figure 11] 1 is a perspective view showing a state in which a pair of first side walls of a box body of a packaging box according to one embodiment of the present invention are erected. FIG. [Figure 12] 1 is a perspective view showing a state in which two pairs of inner folding pieces of a box body of a packaging box according to one embodiment of the present invention are connected together. FIG. [Figure 13] 1 is a perspective view showing a state in which a pair of second side walls of a box body of a packaging box according to one embodiment of the present invention are erected. FIG. [Figure 14] 1 is a perspective view showing a part of a packaging box according to an embodiment of the present invention, in an assembled form; [Figure 15] FIG. 11 is a perspective view showing a box body of a packaging box according to a modified example of an embodiment of the present invention. [Figure 16] FIG. 11 is a perspective view of a packaging box according to a modified example of an embodiment of the present invention, showing a box body in a folded state. [Figure 17] FIG. 11 is a plan view showing a blank for a box body of a packaging box according to a modified example of an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Hereinafter, an embodiment of the present invention will be described with reference to the attached drawings. Note that Fr, Rr, L, R, U, and D shown in the drawings indicate front, rear, left, right, top, and bottom. The front-back direction (first direction), left-right direction (second direction), and up-down direction are mutually perpendicular. Terms indicating directions and positions are used in this specification, but these terms are used for convenience of explanation and do not limit the technical scope of the present invention. In addition, the terms indicating directions and positions are based on the directions and positions in the assembled state of the packaging box.

[0014] An example of a packaging box 1 according to an embodiment will be described with reference to Fig. 1 to Fig. 3. Fig. 1 is a perspective view showing the packaging box 1. Fig. 2 is a plan view showing a blank 3A of a box body 3 of the packaging box 1. Fig. 3 is a plan view showing a blank 5A of a lid body 5 of the packaging box 1.

[0015] As shown in FIG. 1, the packaging box 1 includes a tray-shaped box body 3 and a lid body 5 that opens and closes an upper opening 6 of the box body 3, and has an overall appearance of a substantially rectangular parallelepiped. As will be described in detail later, the box body 3 is deformed between a folded form F1 in which it is folded flat and an assembled form F2 in which it is capable of accommodating contents (not shown). The box body 3 and the lid body 5 are assembled from blanks 3A and 5A (paper corrugated cardboard sheets), respectively. The corrugated cardboard sheet is, for example, a double-sided corrugated cardboard sheet in which liners are attached to both the front and back sides of a corrugated core 9A. Note that FIGS. 2 and 3 show the front side (outer surface). In this specification, the direction parallel to the core 9A of the corrugated cardboard sheet is referred to as the "corrugation direction" (symbol "X"), and the direction perpendicular to the corrugation direction is referred to as the "flow direction" (symbol "Y").

[0016] [Box body blank] As shown in Fig. 2, the blank 3A of the box body 3 includes a bottom wall 10, a pair of first side walls 11, a pair of second side walls 12, two pairs of inner folding pieces 13A and 13B, a pair of folding pieces 14, and a pair of turn-up pieces 15. In Fig. 2, the pair of first side walls 11 are shaped to be line-symmetrical in the row direction (front-rear direction) with the bottom wall 10 as the center, so this specification will mainly describe one first side wall 11. In addition, the pair of second side walls 12, the pair of inner folding pieces 13A, the pair of inner folding pieces 13B, the pair of folding pieces 14, and the pair of turn-up pieces 15 are shaped to be line-symmetrical in the flow direction (left-right direction) with the bottom wall 10 as the center, so this specification will mainly describe one second side wall 12, one inner folding piece 13A, one inner folding piece 13B, one folding piece 14, and one turn-up piece 15. Furthermore, in this specification, in the description common to the first side wall 11 and the second side wall 12, they are simply referred to as "side walls 11, 12." In the description common to the front inner folding piece 13A and the rear inner folding piece 13B, only Arabic numerals are used as reference characters.

[0017] <Bottom wall, first side wall, second side wall> The bottom wall 10 is formed in a substantially rectangular shape with the flow direction as the long side. The pair of first side walls 11 are connected to both ends of the bottom wall 10 in the step direction (first direction) via a first lower fold line 21A. The pair of second side walls 12 are connected to both ends of the bottom wall 10 in the flow direction (second direction) via a second lower fold line 22A. The first side wall 11 and the second side wall 12 are formed in a substantially rectangular shape that have substantially the same height when the box main body 3 is assembled. The dimension (height) of the first side wall 11 in the step direction and the dimension (height) of the second side wall 12 in the flow direction are slightly shorter than the dimension of the bottom wall 10 in the step direction (front-rear direction). In addition, the second side wall 12 is cut with a substantially U-shaped handle cutout 30, and by folding the area defined by the handle cutout 30 at a pair of handle fold lines 23, a handle hole (not shown) into which a user carrying the box main body 3 can insert his / her hand is opened.

[0018] <Details of the first side wall> The first side wall 11 has a first top fold line 21B formed at a position close to the bottom wall 10 (lower side). The first top fold line 21B is formed parallel to the first bottom fold line 21A with a first interval 27A, 27B therebetween. The first side wall 11 is connected to the bottom wall 10 via a double line of the first bottom fold line 21A and the first top fold line 21B. The first side wall 11 is divided into a first frame portion 11A and a first main body portion 11B by the first top fold line 21B. The first frame portion 11A is formed between the first bottom fold line 21A and the first top fold line 21B, and is connected to the bottom wall 10 via the first bottom fold line 21A. The first main body portion 11B is connected to the first frame portion 11A via the first top fold line 21B. The first frame portion 11A (first interval 27B) on one side in the row direction (rear) is formed wider than the first frame portion 11A (first interval 27A) on the other side in the row direction (front). As an example, the front first frame portion 11A (first interval 27A) has a width equivalent to about two cardboard sheets, and the rear first frame portion 11A (first interval 27B) has a width equivalent to about five cardboard sheets. In this specification, in the explanation common to the first intervals 27A and 27B, only Arabic numerals are used as the symbols.

[0019] <Details of the second side wall> The second side wall 12 has a second top fold line 22B formed at a position close to the bottom wall 10 (lower side). The second top fold line 22B is formed parallel to the second bottom fold line 22A with a second interval 28A, 28B between them. The second side wall 12 is connected to the bottom wall 10 via a double line of the second bottom fold line 22A and the second top fold line 22B. The second side wall 12 is divided into a second frame portion 12A and a second main body portion 12B by the second top fold line 22B. The second frame portion 12A is formed between the second bottom fold line 22A and the second top fold line 22B, and is connected to the bottom wall 10 via the second bottom fold line 22A. The second main body portion 12B is connected to the second frame portion 12A via the second top fold line 22B. The second frame portion 12A (second interval 28B) on one side (right side) in the flow direction is formed wider than the second frame portion 12A (second interval 28A) on the other side (left side) in the flow direction. As an example, the left second frame portion 12A (second interval 28A) has a width of about six cardboard sheets, and the right second frame portion 12A (second interval 28B) has a width of about seven cardboard sheets. In addition, the second intervals 28A, 28B (minimum value) are set wider than the first intervals 27A, 27B (maximum value). In this specification, in the explanation common to the second intervals 28A, 28B, only Arabic numerals are used as the symbols.

[0020] <Inner folding piece> The two pairs of inner folding pieces 13A, 13B are connected to both ends of the pair of first side walls 11 in the flow direction (second direction) excluding the first intervals 27A, 27B via the one-sided folding line 24. That is, the two pairs of inner folding pieces 13A, 13B are connected only to the pair of first main body parts 11B and extend from the pair of first main body parts 11B to both sides in the flow direction. The inner folding pieces 13 are formed in a roughly rectangular shape, and a handle recess 31 is recessed at the tip side of the inner folding pieces 13 in the flow direction (extension direction). The handle recess 31 coincides with the handle hole (handle cut 30) of the second side wall 12 when the box body 3 is in the assembly form F2. An engagement hole 32 is drilled along the one-sided folding line 24 on the tip side (upper side) of the center of the first side wall 11 in the step direction. The engagement hole 32 is a generally rectangular hole that is elongated in the step direction (vertical direction), and more specifically, is formed so as to slightly bite into the inner folding piece 13B and divide the one-sided folding line 24. Note that the engagement hole 32 is not limited to a generally rectangular hole, and may be, for example, a simple cut (slit) (not shown).

[0021] A grooved portion 33 having a width equivalent to the first interval 27A is formed at the boundary between the front inner folded piece 13A and the second side wall 12. A missing page portion 34 having a width equivalent to the first interval 27B is formed at the boundary between the rear inner folded piece 13B and the second side wall 12. As described above, since the rear first interval 27B is wider than the front first interval 27A, the missing page portion 34 is a groove (hole) wider than the grooved portion 33. The lower sides of the inner folded pieces 13A and 13B (the side facing the second side wall 12 across the grooved portion 33 and the missing page portion 34) are formed substantially in the same straight line as the first upper fold line 21B.

[0022] Moreover, a hook portion 35 is provided on the front inner folded piece 13A so as to protrude outward from the tip in the flow direction (extension direction). The hook portion 35 is formed in a substantially L-shape bent downward (toward the second side wall 12). Moreover, the front inner folded piece 13A is formed with an upper interlocking groove 36 cut from the inside (lower) to the outside (upper) in the step direction. In other words, the hook portion 35 is bent in a substantially L-shape so as to form the upper interlocking groove 36 with the lower side open.

[0023] <Folding piece> The pair of folding pieces 14 are connected to a pair of inner folding pieces 13B connected to the rear first side wall 11. The folding pieces 14 are connected via an inclined fold line 25 formed obliquely so as to cut the lower corners (corners on the boundary side with the second side wall 12) of the inner folding pieces 13B. The inclined fold line 25 is inclined from the corner of the missing page portion 34 toward the outside of the flow direction toward the outside of the column direction (upward). The inclined fold line 25 is inclined at about 45 degrees with respect to a vertical line parallel to the column direction, for example. The folding pieces 14 are formed in a substantially rectangular shape that protrudes downward (toward the second side wall 12) and fills the first gap 27B. The folding pieces 14 protrude so as to create a step between the inner folding pieces 13B and the missing page portion 34 (first gap 27B), and the tip (lower end) of the folding piece 14 abuts against the side of the second side wall 12 (second main body portion 12B). Further, a lower interlocking groove 37 is formed in the folded piece 14, which is cut from the outside (upper) to the inside (lower) in the row direction. To be precise, the lower interlocking groove 37 is a cut that opens upward and is formed along the boundary between the folded piece 14 and the inner folded piece 13B. The inclined fold line 25 is formed so as to connect the corner of the missing page portion 34 and the lower end of the lower interlocking groove 37.

[0024] <Folded piece> The folded piece 15 is formed in a substantially rectangular shape and is connected to the outer end (upper end) of the second side wall 12 in the flow direction via a pair of folding lines 26. The pair of folding lines 26 are formed in parallel with an interval of about two cardboard sheets. A pair of engagement protrusions 38 are provided on the leading end side of the folded piece 15 in the flow direction and on both ends in the step direction, protruding outward in the step direction. The engagement protrusions 38 are provided so as to be able to fit into the engagement holes 32 opening in the first side wall 11. A handle inner hole 39 is drilled on the leading end side of the folded piece 15 in the flow direction. The handle inner hole 39 is formed to coincide with the handle hole (handle cutout 30) of the second side wall 12 when the box body 3 is in the assembly form F2 (see FIG. 1 and FIG. 13, etc.).

[0025] The first bottom fold line 21A, the first top fold line 21B, the second bottom fold line 22A, the second top fold line 22B, the handle fold line 23, the one-sided fold line 24, the inclined fold line 25, and the fold-back line 26 are general-purpose creases that dent the cardboard sheet from the back surface (inner surface). The general-purpose creases mainly function to fold the cardboard sheet so that the back surface faces inward (forward folding). The above-mentioned first bottom fold line 21A and the like are not limited to general-purpose creases, and may be any lines for folding the cardboard sheet in a desired direction. In this specification, the first bottom fold line 21A and the first top fold line 21B are referred to as the "first fold line 21" in a description common to both the first bottom fold line 21A and the first top fold line 21B, and only Arabic numerals are used as the symbols. Similarly, the second bottom fold line 22A and the second top fold line 22B are referred to as the "second fold line 22" in a description common to both the second bottom fold line 22A and the second top fold line 22B, and only Arabic numerals are used as the symbols. Furthermore, in the description common to the first fold line 21 and the second fold line 22, they will simply be referred to as "fold lines 21, 22."

[0026] [Lid blank] As shown in FIG. 3, the blank 5A of the cover 5 includes a top wall 40, a pair of first top side walls 41, a pair of second top side walls 42, and four top fold-in pieces 43. In FIG. 3, the pair of first top side walls 41 are symmetrical in the flow direction (front-rear direction) with the top wall 40 as the center, so this specification mainly describes one first top side wall 41. In addition, the pair of second top side walls 42 are symmetrical in the row direction (left-right direction) with the top wall 40 as the center, so this specification mainly describes one second top side wall 42. In addition, the four top fold-in pieces 43 are shaped by rotating 90 degrees each around the centroid (center) of the top wall 40, so this specification mainly describes one top fold-in piece 43.

[0027] The top wall 40 is substantially rectangular with the long side in the step direction, and is formed to be slightly larger than the bottom wall 10 of the box body 3. The pair of first top side walls 41 are connected to both ends of the top wall 40 in the flow direction via the first top folding line 51. The pair of second top side walls 42 are arranged at both ends of the top wall 40 in the step direction. The second top side wall 42 has a second outer wall 42A connected to the end of the top wall 40 in the step direction via the second top folding line 52, and a second inner wall 42B connected to the tip of the second outer wall 42A via a pair of second folding lines 53. Four lid engagement holes 44 are drilled in the top wall 40 along the pair of second top folding lines 52, and four lid engagement protrusions 45 are protruded from the tips of the pair of second inner walls 42B. The four top fold pieces 43 are connected to both ends of the pair of first top side walls 41 in the row direction via top fold lines 54. Note that the first top fold line 51, the second top fold line 52, the second fold back line 53 and the top fold line 54 are general-purpose lines, but are not limited thereto and may be any lines for folding the cardboard sheet in a desired direction.

[0028] [Assembly of the lid] The lid body 5 is assembled by folding the blank 5A at appropriate positions in a predetermined order. Specifically, the first top side wall 41 is folded generally at a right angle along the first top folding line 51, and the top folding piece 43 is folded generally at a right angle inward along the top folding line 54. Next, the second outer wall 42A is folded generally at a right angle along the second top folding line 52, and the second inner wall 42B is folded back along a pair of second folding lines 53 to sandwich the top folding piece 43 between the second outer wall 42A and the top folding piece 43. The top folding piece 43 is enclosed in the second top side wall 42, and the lid engagement protrusion 45 protruding from the second inner wall 42B fits into the lid engagement hole 44 drilled in the top wall 40. The pair of first top side walls 41 and the pair of second top side walls 42 form a lid tube portion 46 (see FIG. 1) that is suspended downward from the peripheral portion of the top wall 40. Through the above steps, a tray-shaped lid body 5 with an open bottom is completed (see FIG. 1).

[0029] [Folded form] Next, a procedure for folding the unfolded box body 3 (blank 3A) into the folded form F1 will be described with reference to Figs. 4 to 10. Fig. 4 is a perspective view showing a state in which the folding piece 14 is folded back. Fig. 5 is a perspective view showing a state in which the inner folding piece 13 is folded back. Fig. 6 is a perspective view showing a state in which the front first side wall 11 is folded back. Fig. 7 is a perspective view showing a state in which the pair of first side walls 11 are folded back. Fig. 8 is a perspective view showing a state in which the left second side wall 12 is folded back. Fig. 9 is a perspective view showing the box body 3 in the folded form F1. Fig. 10 is a perspective view showing a state in which the box body 3 in the folded form F1 is housed in the lid 5.

[0030] The unfolded box body 3 (blank 3A) is oriented with the back surface (inner surface) facing upward, and is folded in a predetermined manner at appropriate places to become a folded form F1. Here, as an example, a case where a worker transforms the blank 3A of the box body 3 into the folded form F1 will be described.

[0031] When the box body 3 is folded into the folding form F1, as shown in FIG. 4, the folding piece 14 is folded inward along the inclined fold line 25 (folded approximately 180 degrees forward) and stacked on the inner surface of the inner folding piece 13B. Then, as shown in FIG. 5, the four inner folding pieces 13A, 13B are folded inward along the one-sided fold line 24 (folded approximately 180 degrees forward) and stacked on the inner surface of the first side wall 11. To be precise, each inner folding piece 13 is stacked on the inner surface of the first main body portion 11B, and is not stacked on the inner surface of the first frame portion 11A. Therefore, the first frame portion 11A (first lower fold line 21A, first upper fold line 21B) is exposed. At this time, the rear inner folding piece 13B is stacked on the inner surface of the first side wall 11 with the folding piece 14 sandwiched therebetween.

[0032] 6, the front first side wall 11 is folded inward along the first lower fold line 21A and the first upper fold line 21B and stacked on the bottom wall 10 with the inner fold piece 13 sandwiched between them. In detail, the front first frame portion 11A is folded at a substantially right angle along the first lower fold line 21A and stands upright relative to the bottom wall 10, and the front first main body portion 11B is folded at a substantially right angle along the first upper fold line 21B and becomes substantially horizontal, covering substantially the entire bottom wall 10.

[0033] 7, the rear first side wall 11 is folded inward along the first lower fold line 21A and the first upper fold line 21B. In detail, the rear first frame portion 11A is folded at a substantially right angle at the first lower fold line 21A to stand up against the bottom wall 10, and the rear first main body portion 11B is folded at a substantially right angle at the first upper fold line 21B to become substantially horizontal and cover substantially the entire front first main body portion 11B stacked on the bottom wall 10. The rear first main body portion 11B is stacked on the front first main body portion 11B with the folding piece 14 and the inner folding piece 13 sandwiched therebetween. As described above, since the rear first frame portion 11A (first interval 27B) is wider than the front first frame portion 11A (first interval 27A) (see FIG. 2), the rear first upper fold line 21B is located higher than the front first side wall 11 (first main body portion 11B) stacked on the bottom wall 10. Therefore, the rear first main body portion 11B is folded along the first upper fold line 21B without interfering with the front first main body portion 11B stacked on the bottom wall 10.

[0034] Next, as shown in FIG. 8, the left second side wall 12 is folded inward along the second lower fold line 22A and the second upper fold line 22B, and is stacked on the bottom wall 10 with the pair of folded first side walls 11 in between. In detail, the left second frame portion 12A is folded at a substantially right angle along the second lower fold line 22A to stand up against the bottom wall 10, and the left second main body portion 12B (including the folded back piece 15) is folded at a substantially right angle along the second upper fold line 22B to become substantially horizontal and cover substantially the entire rear first main body portion 11B. As described above, since the left second frame portion 12A (second interval 28A) is wider than the rear first frame portion 11A (second interval 28B) (see FIG. 2), the left second upper fold line 22B is located above the pair of first side walls 11 (first main body portion 11B) stacked on the bottom wall 10. Therefore, the left second main body portion 12B is folded along the second upper folding line 22B without interfering with the pair of stacked first main body portions 11B.

[0035] 9, the right second side wall 12 is folded inward along the second lower fold line 22A and the second upper fold line 22B. In detail, the right second frame portion 12A is folded at a substantially right angle at the second lower fold line 22A to stand up against the bottom wall 10, and the right second main body portion 12B (including the folded back piece 15) is folded at a substantially right angle at the second upper fold line 22B to become substantially horizontal and cover substantially the entire left second main body portion 12B. As described above, since the right second frame portion 12A (second interval 28B) is wider than the left second frame portion 12A (second interval 28A) (see FIG. 2), the right second upper fold line 22B is located above the stacked left second side wall 12 (second main body portion 12B). Therefore, the right second main body portion 12B is folded along the second upper fold line 22B without interfering with the stacked left second main body portion 12B.

[0036] As described above, the pair of first side walls 11 are folded back in the order of narrowest width of the first frame portions 11A (first gaps 27A, 27B), and then the pair of second side walls 12 are folded back in the order of narrowest width of the second frame portions 12A (second gaps 28A, 28B), thereby completing the box body 3 transformed into the folding form F1 (see Figure 9).

[0037] 10, the box body 3 in the folded form F1 is stored in an area surrounded by the top wall 40 and the tubular lid portion 46. That is, the box body 3 in the folded form F1 is fitted into the lid 5. At this time, the box body 3 is stored in a position in which the second right side wall 12 (the second body portion 12B and the folded-back piece 15) faces (contacts) the inner surface of the top wall 40 and the bottom wall 10 is exposed. In this way, the packaging box 1 is folded as a whole to approximately the same size as the lid 5, and is distributed in this form.

[0038] In the packaging box 1 (box body 3) according to the present embodiment described above, the side walls 11, 12 are connected to the bottom wall 10 via two parallel fold lines 21, 22 (see FIG. 2). With this configuration, the side walls 11, 12 can be folded at two fold lines 21, 22 (two locations) at approximately 90 degrees each, so that the bending stress (bending load) is distributed to two locations, and the repulsive force around the fold lines 21, 22 can be weakened. This suppresses the occurrence of tears along the fold lines 21, 22, and also suppresses the side walls 11, 12 from opening due to the repulsive force. As a result, the box body 3 can be folded compactly, and the folded state (folded form F1) of the box body 3 can be properly maintained.

[0039] Incidentally, in order to ensure the compressive strength of the box body 3 in the assembly form F2 described later, it is preferable that the lower ends of the inner folding pieces 13 and the folding pieces 14 abut against the bottom wall 10. If the grooved portion 33 and the missing page portion 34 are omitted in order to abut the lower ends of the inner folding pieces 13 and the folding pieces 14 against the bottom wall 10, when the inner folding pieces 13 and the like are folded back and stacked on the inner surface of the first side wall 11, the inner folding pieces 13 and the folding pieces 14 cross the first upper fold line 21B and cover a part of the first frame portion 11A. Then, the inner folding pieces 13 and the folding pieces 14 get in the way, making it impossible to fold the first side wall 11 (first main body portion 11B) at the first upper fold line 21B. Therefore, in the packaging box 1 (box body 3) according to this embodiment, the inner folding piece 13 is connected only to the first main body portion 11B, and the grooved portion 33 and the missing page portion 34 corresponding to the first frame portion 11A are configured to be open (see FIG. 2). In addition, the folding piece 14 is configured to be folded back at the inclined fold line 25 and overlap the inner surface of the inner folding piece 13B (see FIG. 4). With this configuration, the folded back inner folding piece 13 and the folding piece 14 do not cross the first upper fold line 21B and overlap the first frame portion 11A, and the two first fold lines 21 and the first frame portion 11A can be exposed (see FIG. 5). This allows the first side wall 11 to be folded appropriately along the two first fold lines 21.

[0040] Furthermore, with the packaging box 1 according to this embodiment, the box body 3 in the folded form F1 is stored in the lid body 5 and integrated with the lid body 5, so that the entire packaging box 1 can be made roughly the same size as the lid body 5 (see FIG. 10). This makes it easier to secure a storage space and to transport the box.

[0041] [Assembly form] Next, a procedure for transforming the box body 3 from the folded form F1 to the assembled form F2, in other words, a procedure for assembling the box body 3 and using the packaging box 1, will be described with reference to Fig. 1 and Fig. 11 to Fig. 14. Fig. 11 is a perspective view showing a state in which a pair of first side walls 11 are erected. Fig. 12 is a perspective view showing a state in which two pairs of inner folding pieces 13 are connected. Fig. 13 is a perspective view showing a state in which a pair of second side walls 12 are erected. Fig. 14 is a perspective view showing a part of the box body 3 in the assembled form F2.

[0042] The box body 3 in the folded form F1 is taken out (separated) from the lid 5 and folded at appropriate places in a predetermined procedure to be brought into the assembled form F2. Here, as an example, a case where a worker transforms the box body 3 from the folded form F1 to the assembled form F2 will be described.

[0043] When the box body 3 is put into the assembled form F2, the above-mentioned procedure for transforming the blank 3A into the folded form F1 is reversed to unfold the box body 3. That is, the pair of second side walls 12, the pair of first side walls 11, and the two pairs of inner folding pieces 13 are unfolded in order, and the folding pieces 14 folded at the inclined folding lines 25 are returned (see FIG. 2).

[0044] 11, a pair of first side walls 11 are erected on both ends in the front-rear direction of the bottom wall 10. The lower part of the first side wall 11 has creases formed by two first folding lines 21, and is bent in two stages. Therefore, the first side wall 11 does not assume an upright position.

[0045] 11 and 12, the two pairs of inner folding pieces 13A, 13B are folded inward at a substantially right angle along the one-side folding line 24, and are extended from both ends of the pair of first side walls 11 in the left-right direction toward the center in the front-rear direction, and are connected at the center in the front-rear direction. Specifically, the upper interlocking groove 36 formed in the front inner folding piece 13A facing the rear folding piece 14 is interlocked from above with the lower interlocking groove 37 formed in the folding piece 14. At this time, it is preferable that the hook portion 35 of the front inner folding piece 13A and the rear folding piece 14 are crossed so as to be positioned outside each other. By crossing in this manner, the front hook portion 35 is brought into close contact with the outer surface of the rear inner folding piece 13B, and the rear folding piece 14 is straightened from the fold at the inclined folding line 25, and its inner surface is brought into close contact with the outer surface of the front inner folding piece 13A. It is also possible to reduce the range in which the hook portion 35 and the folding piece 14 are exposed inside the box body 3. The tips of the pair of front and rear inner folding pieces 13A, 13B overlap each other.

[0046] Since the folding pieces 14 protrude downward by an amount corresponding to the first interval 27B, the two pairs of inner folding pieces 13A, 13B are connected at the center in the front-rear direction and erected at both ends in the left-right direction of the bottom wall 10, so that the lower ends of the pair of folding pieces 14 are pressed against (the upper surface of) the bottom wall 10 (see FIG. 12). When the lower ends of the pair of folding pieces 14 are pressed against the bottom wall 10, the pair of first side walls 11 are pushed up (see the dashed arrows in FIG. 14). As a result, the folds formed by the two first fold lines 21 at the lower part of the first side wall 11 are straightened, and the first side wall 11 is in a substantially upright position (see FIG. 14). The lower ends of the inner folding pieces 13A, 13B do not contact the upper surface of the bottom wall 10, and a groove cut portion 33 and a missing page portion 34 are opened between the lower ends of the inner folding pieces 13A, 13B and the upper surface of the bottom wall 10 (see FIG. 12).

[0047] 13, a pair of second side walls 12 are erected on both left and right ends of the bottom wall 10 so as to cover the outer surfaces of the two pairs of inner folding pieces 13. The lower part of the second side wall 12 has a crease caused by two second folding lines 22, and is bent in two stages. Therefore, the second side wall 12 does not assume an upright position.

[0048] Next, the folded piece 15 is folded inward along the pair of folding lines 26 while pulling up the second side wall 12 (see FIG. 1). Since the height of the second side wall 12 is substantially the same as the height of the inner folded piece 13 including the first side wall 11 and the folding piece 14, the connection portion (between the pair of folding lines 26) between the second side wall 12 and the folded piece 15 is pressed against the upper ends of the pair of front and rear inner folded pieces 13A, 13B. Then, the second side wall 12 is pulled up (see the dashed arrow in FIG. 14), the folds formed by the two second folding lines 22 at the lower part of the second side wall 12 are straightened, and the second side wall 12 assumes a substantially upright position (see FIG. 14). In addition, when the folded piece 15 is folded back along the pair of folding lines 26, the pair of engaging protrusions 38 of the folded piece 15 are fitted into the engaging holes 32 opened in the pair of first side walls 11 (see FIGS. 1 and 14). As a result, the folded piece 15 folded back at the pair of folding lines 26 is fixed between the second side wall 12 (the upper part thereof) and the pair of front and rear inner folded pieces 13A, 13B in a sandwiched state.

[0049] Through the above steps, the box body 3 transformed into the assembled form F2 is completed (see Figs. 1 and 14). The box body 3 in the assembled form F2 is formed in a tray shape with a pair of first side walls 11 and a pair of second side walls 12 standing on the peripheral portion of the bottom wall 10 (see Fig. 1). In this state, an upper opening 6 is formed in the area surrounded by the upper edges of the pair of first side walls 11 and the pair of second side walls 12 (Fig. 1). The lid 5 is placed on the top of the box body 3 so as to close the upper opening 6.

[0050] In the packaging box 1 according to the present embodiment described above, when the box body 3 is transformed from the folded form F1 to the assembled form F2, the lower end of the folding piece 14 is pressed against the bottom wall 10 to push up the pair of first side walls 11, and the folded-back piece 15 is folded back to cover the pair of front and rear inner folded pieces 13, thereby pulling up the second side wall 12. This configuration makes it possible to straighten out the folds (warping) at the lower parts of the side walls 11, 12 (see FIG. 14). This allows the side walls 11, 12 to be in a substantially upright position, and the box body 3 in the assembled form F2 can be made into a substantially rectangular parallelepiped shape with little warping. In other words, the appearance (beauty) of the box body 3 can be maintained in a good condition.

[0051] Furthermore, in the packaging box 1 according to this embodiment, when the two pairs of inner folding pieces 13A, 13B are connected at the center in the front-rear direction, the lower interlocking grooves 37 of the pair of folding pieces 14 and the upper interlocking grooves 36 of the pair of inner folding pieces 13A are interlocked with each other. With this configuration, the front inner folding piece 13A is supported by the rear folding piece 14, and the lower end of the folding piece 14 is pressed against the bottom wall 10, thereby pushing up both the front and rear first side walls 11. As a result, for example, it is only necessary to form the folding piece 14 at the rear, so that the structure of the box body 3 can be simplified and the work of deforming the box body 3 can be made easier.

[0052] In the packaging box 1 according to the present embodiment, the box body 3 is formed in a relatively deep tray shape in the assembled form F2 (see FIG. 1), and the pair of first side walls 11 and the like are stacked on the bottom wall 10 so as to overlap each other in the folded form F1 (see FIG. 9), but the present invention is not limited thereto. As shown in FIG. 15, as a packaging box 2 according to a modified example, the box body 4 in the assembled form F2 may be formed in a relatively shallow tray shape. As shown in FIG. 16, in the box body 4 in the folded form F1, the pair of first side walls 11 do not overlap each other on the bottom wall 10, and the pair of second side walls 12 do not overlap each other on the pair of first side walls 11. The tips of the pair of first side walls 11 and the tips of the pair of second side walls 12 are spaced apart from each other, but may be butted together. As shown in FIG. 17, in the box body 4 (blank 4A), the rear first frame portion 11A (first interval 27B) is formed wider than the front first frame portion 11A (first interval 27A), and the pair of second frame portions 12A (second intervals 28A, 28B) are formed to have the same width. Also, the inclined fold line 25 is formed so as to connect the corner of the missing page portion 34 and a position shifted upwardly of the lower meshing groove 37. According to the packaging box 2 according to the modified example, the pair of first side walls 11 can be folded back substantially simultaneously, and the pair of second side walls 12 can be folded back substantially simultaneously. This makes it possible to quickly transform the packaging box 2 into the folding form F1 without having to worry about the order of folding.

[0053] In the packaging boxes 1 and 2 according to the present embodiment (including modified examples, the same applies below), the pair of folding pieces 14 is provided only on the pair of inner folding pieces 13B located at the rear, but the present invention is not limited to this. For example, four folding pieces 14 may be connected to the four inner folding pieces 13 (not shown). Also, for example, the pair of front and rear inner folding pieces 13A, 13B (folding pieces 14) may be switched in one of the left and right directions, so that two folding pieces 14 are connected to two inner folding pieces 13 located diagonally between the pair of first side walls 11 (bottom wall 10) (not shown).

[0054] In addition, in the packaging boxes 1 and 2 according to the present embodiment, the inclined fold line 25 is inclined at about 45 degrees with respect to the vertical line, but the present invention is not limited to this. The inclined fold line 25 may be formed at an angle that allows the folding piece 14 to be folded back so that the folding piece 14 does not overlap the first frame portion 11A when the inner folding piece 13 is folded back.

[0055] In addition, in the packaging boxes 1 and 2 according to the present embodiment, the rear first frame portion 11A (first interval 27B) is formed wider than the front first frame portion 11A (first interval 27A), but this is not limited thereto, and for example, the pair of front and rear first frame portions 11A (first intervals 27A, 27B) may be formed to have the same width (not shown). Similarly, the pair of left and right second frame portions 12A (second intervals 28A, 28B) may be formed to have the same width (not shown).

[0056] In addition, in the packaging boxes 1 and 2 according to the present embodiment, the pair of front and rear inner folded pieces 13A and 13B are connected by engaging the lower interlocking groove 37 and the upper interlocking groove 36, but the present invention is not limited to this. For example, a convex portion may be formed at the tip of one of the inner folded pieces 13 in the front-rear direction, and a concave portion may be formed at the tip of the other inner folded piece 13 in the front-rear direction, and the pair of front and rear inner folded pieces 13A and 13B may be connected by fitting the convex portion into the concave portion (not shown). Alternatively, the pair of front and rear inner folded pieces 13A and 13B may be connected via an adhesive tape, adhesive, staples, or the like (not shown).

[0057] In addition, in the packaging boxes 1 and 2 according to the present embodiment, the folded piece 15 is connected to the upper end of the second side wall 12 via a pair of folding lines 26, but this is not limited thereto, and the folded piece 15 may be connected to the upper end of the second side wall 12 via a single folding line 26 (not shown). In addition, the folded piece 15 is fixed by engaging the engaging protrusion 38 with the engaging hole 32, but this is not limited thereto, and for example, the engaging protrusion 38 and the engaging hole 32 may be omitted, and the folded piece 15 may be press-fitted and fixed between the pair of first side walls 11, or may be adhered to the inner folded piece 13 (not shown).

[0058] In addition, in the packaging boxes 1 and 2 according to the present embodiment, the folding pieces 14 and the fold-back pieces 15 are provided in consideration of the aesthetic appearance of the box main bodies 3 and 4 in the assembled form F2, but the present invention is not limited thereto. For example, if the bending of the lower part of the second side wall 12 is permitted, the fold-back piece 15 (fold-back line 26) may be omitted (not shown). For example, if the bending of the lower part of the first side wall 11 is permitted, the folding piece 14 (inclined fold line 25) may be omitted (not shown). For example, if the aesthetic appearance of the box main bodies 3 and 4 in the assembled form F2 is not an issue, both the fold-back piece 15 and the folding piece 14 may be omitted (not shown). For example, the pair of front and rear inner fold-back pieces 13A and 13B may not be connected to each other and may be bonded to the inner surface of the second side wall 12 (not shown). Also, for example, two pairs of inner folding pieces 13 may be provided continuously at both ends in the front-rear direction of the pair of second side walls 12, and each inner folding piece 13 may be adhered to the inner surface of the first side wall 11 (not shown). Furthermore, for example, the inner folding pieces 13 may be omitted, and the first side wall 11 and the second side wall 12 may be connected with an adhesive tape or the like (not shown).

[0059] In addition, in the packaging boxes 1 and 2 according to the present embodiment, the bottom wall 10 of the box main body 3 and 4 is formed in a substantially rectangular shape (quadrilateral shape), but the present invention is not limited thereto. The bottom wall 10 may be formed in a polygonal shape having at least four sides, and may be formed in a substantially octagonal shape by cutting out the four corners obliquely (not shown). Similarly to the bottom wall 10, the top wall 40 of the lid body 5 may also be formed in a polygonal shape capable of closing the top opening 6 of the box main body 3 and 4 (not shown).

[0060] In addition, in the packaging boxes 1 and 2 according to the present embodiment, the lid body 5 is configured as a separate body from the box main bodies 3 and 4, but the present invention is not limited to this. For example, a flap for opening and closing the top opening 6 may be provided continuously to the upper end of at least one of the pair of first side walls 11 (not shown). Also, for example, one of the pair of folded pieces 15 may be extended and used as a lid for opening and closing the top opening 6 (not shown). When the folded form F1 is used, the flap or lid for opening and closing the top opening 6 may be folded back so as to be stacked on the inner surface of the first side wall 11 or the second side wall 12, or may be left extended (not shown). Furthermore, the lid body 5 may be omitted, and the packaging box 1 according to the present embodiment may be configured only by the box main bodies 3 and 4 (not shown).

[0061] In addition, in the packaging boxes 1 and 2 according to the present embodiment, the box bodies 3 and 4 and the lid body 5 are formed from a double-sided corrugated cardboard sheet made of paper, but this is not limiting and they may be formed from a single-sided corrugated cardboard sheet, double-sided corrugated cardboard sheet, thick paper, a resin plate (sheet), etc. In addition, the box bodies 3 and 4 and the lid body 5 do not need to be formed from the same material and may be formed from different materials.

[0062] The above embodiment is merely an example of the packaging box of the present invention, and the technical scope of the present invention is not limited to the above embodiment. The present invention may be modified, substituted, or altered in various ways without departing from the spirit of the technical idea, and the claims include all embodiments that may be included within the scope of the technical idea. [Explanation of symbols]

[0063] 1, 2 packaging box 3, 4 Boxes 5 Lid 6 Top opening 10 Bottom wall 11 First side wall 12 Second side wall 13A,13B Inner fold piece 14 Folding piece 15 Folded piece 21A 1st lower fold line 21B 1st upper fold line 22A Second lower fold line 22B Second upper fold line 24 Piecewise fold line 25 Inclined fold line 26 Reversed fold line 27A, 27B First interval 28A, 28B Second interval 36 Upper meshing groove 37 Lower meshing groove 40 Top wall 46 Cover cylinder part F1 Folded form F2 Assembled form

Claims

1. A packaging box (1, 2) including a box body (3, 4) that is deformable between a folded state (F1) in which the box body is folded flat and an assembled state (F2) in which an item can be stored, The box body includes: A bottom wall (10) formed in a polygonal shape having at least four sides; A pair of first side walls (11) connected to both ends of the bottom wall in a first direction via a first lower fold line (21A); a pair of second side walls (12) connected to both ends of the bottom wall in a second direction perpendicular to the first direction via a second lower fold line (22A); The first side wall has a first upper fold line (21B) formed parallel to the first lower fold line with a first interval (27A, 27B) therebetween, The second side wall has a second upper fold line (22B) formed parallel to the second lower fold line at a second interval (28A, 28B) wider than the first interval, When the box body is in the folded form, the first side wall is folded inwardly along the first lower fold line and the first upper fold line and stacked on the bottom wall, and the second side wall is folded inwardly along the second lower fold line and the second upper fold line and stacked on the bottom wall with the first side wall therebetween, A packaging box, characterized in that, when the box body is in the assembled form, the first side wall and the second side wall are provided upright relative to the bottom wall.

2. The box body includes: Two pairs of inner folding pieces (13A, 13B) are connected to both ends of the pair of first side walls in the second direction excluding the first interval via one-sided folding lines (24); At least one pair of folded pieces (14) are connected to at least one of the pair of first side walls, or at least two of the inner folded pieces located at diagonal corners of the pair of first side walls, via an inclined fold line (25) formed obliquely so as to cut a lower corner of the inner folded piece, The folded piece is formed to protrude downward to fill the first gap, When the box body is folded into the folded form, the folding piece is folded inward along the inclined fold line and stacked on the inner surface of the inner folding piece, the inner folding piece is folded inward along the one fold line and stacked on the inner surface of the first side wall, the first side wall is stacked on the bottom wall with the inner folding piece in between, and the second side wall is stacked on the bottom wall with the first side wall in between.

2. The packaging box according to claim 1, wherein, when the box body is assembled, the folded pieces folded at the inclined fold lines are returned, a pair of the first side walls are erected on both ends of the bottom wall in the first direction, and two pairs of the inner folded pieces extend from both ends of the pair of the first side walls in the second direction toward a center in the first direction and are connected at a center portion in the first direction and erected on both ends of the bottom wall in the second direction, so that lower ends of the folded pieces are pressed against the bottom wall to push up the pair of first side walls, and a pair of the second side walls are erected to cover outer surfaces of the two pairs of the inner folded pieces.

3. The pair of folding pieces are connected to a pair of inner folding pieces connected to one of the pair of first side walls, or to two inner folding pieces located diagonally between the pair of first side walls, The folded piece is formed with a lower interlocking groove (37) cut downward from above, The other inner folded piece facing the folded piece has an upper interlocking groove (36) cut from below to above, 3. The packaging box according to claim 2, characterized in that, in the process of assembling the box body into the assembled form, when the two pairs of inner folding pieces are connected at the center in the first direction, the lower interlocking grooves of the pair of folding pieces and the upper interlocking grooves of the pair of inner folding pieces are interlocked with each other.

4. The box body further includes a pair of fold pieces (15) connected to the upper ends of the pair of second side walls via fold lines (26), 4. The packaging box according to claim 2 or 3, characterized in that, in the process of assembling the box body into the assembled form, a pair of the second side walls are erected so as to cover the outer surfaces of the two pairs of inner folding pieces, and the pair of folding pieces are folded inwardly along the folding lines while pulling up the pair of the second side walls, and are fixed in a state in which the two pairs of inner folding pieces are sandwiched between the pair of the second side walls.

5. a lid (5) for opening and closing a top opening (6) surrounded by upper edges of the pair of first side walls and the pair of second side walls when the box body is in the assembled form, The lid body is A top wall (40) formed in a polygonal shape capable of closing the upper surface opening; a tubular lid portion (46) extending downward from the peripheral edge of the top wall, 4. The packaging box according to claim 1, wherein the box body in the folded state is accommodated in an area surrounded by the top wall and the tubular lid portion.

Images