Packing box

Abstract

To suppress breakage of a corner portion due to biting of a band in a packaging box.SOLUTION: There is provided a packaging box 1 having a corner portion 31 formed by bending two surface portions 11 and 13 connected to each other along a boundary line, the packaging box including a ridgeline 51 and a slit 61. The ridgeline 51 extends on the boundary line between the two surface portions 11 and 13 at the corner portion 31. The slit 61 is cut in a convex shape from the ridgeline 51 in either one of the two surface portions 11 and 13.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] This case relates to a packaging box that can be strapped. [Background technology]

[0002] Packaging boxes for packaging goods are sometimes wrapped with bands to prevent unintentional opening and to improve transportability. Packaging boxes wrapped with bands have the problem that the corners, where stress is concentrated due to the tightening force of the bands, are prone to tearing and crushing. In response to this problem, Patent Document 1 proposes a technique in which leaf-shaped lines (folds) are provided at the corners of a cardboard packaging box, and the areas surrounded by these lines are recessed inward of the packaging box. With the technique disclosed in Patent Document 1, the corners of the packaging box are made obtuse, which can prevent damage to the corners caused by the bands being applied. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Utility Model Application Publication No. 59-38224 Summary of the Invention [Problem to be solved by the invention]

[0004] However, simply providing a score line for folding the corners of the packaging box at an obtuse angle as described above may result in the corners not folding properly at the score line. If the corners are not properly obtuse, there is a risk that the corners may be damaged (unintended tearing or crushing) due to the band digging in. Therefore, there is room for improvement in the technology of Patent Document 1.

[0005] The packaging box of the present invention was invented in consideration of the above-mentioned problems, and one of its objectives is to prevent damage to the corners due to the band digging in. However, in addition to this objective, other objectives of the present invention include the effects and advantages derived from the various configurations shown in the "Mode for Carrying Out the Invention" below, which cannot be obtained with conventional technology. [Means for solving the problem]

[0006] The packaging box in this case is a packaging box in which two connected surfaces are folded along a boundary line to form a corner, and is characterized by having a ridge line extending on the boundary line at the corner, and a slit cut in a convex shape from the ridge line on one of the two surfaces. [Effects of the Invention]

[0007] According to the packaging box of the present invention, damage to the corners due to the band biting into the corners can be suppressed. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a perspective view showing a state in which a band is fastened to a packaging box according to an embodiment. [Figure 2] 2 is a side view (view of the packaging box from the width direction) showing a state in which the packaging box of FIG. 1 is being assembled. FIG. [Figure 3] 2 is a plan view illustrating a slit formed in the packaging box of FIG. 1. FIG. [Figure 4] FIG. 10 is a plan view (corresponding to FIG. 3) illustrating a slit according to a first modified example. [Figure 5] FIG. 10 is a plan view (corresponding to FIG. 3) illustrating a slit according to a second modified example. [Figure 6] FIG. 2 is a development view of the packaging box of FIG. [Figure 7] 2 is a schematic cross-sectional view (a cross-sectional view taken along the line AA in FIG. 1) illustrating the function of the packaging box of FIG. 1. [Figure 8] FIG. 10 is a development view of a packaging box according to a modified example. DETAILED DESCRIPTION OF THE INVENTION

[0009] The following describes embodiments for carrying out the present invention. The embodiments described below are merely examples, and are not intended to exclude various modifications or applications of techniques not explicitly stated herein. The configurations of the following embodiments can be modified in various ways without departing from the spirit of the invention. Furthermore, they can be selected or combined as needed.

[0010] [1. Configuration] [1-1. Packaging box] As shown in Fig. 1, the packaging box 1 of this embodiment has a three-dimensional shape with a space inside for storing items when assembled. Here, the packaging box 1 is a so-called Type A (0201 format) cardboard box (box) as an example.

[0011] The following describes the configuration of the packaging box 1, assuming that the assembled packaging box 1 is placed on a horizontal surface. In the following description, the side of the space inside the packaging box 1 is also referred to as the "inside," and the opposite side is also referred to as the "outside." In addition, the directions related to the packaging box 1 are defined as a depth direction D1, a length direction D2, and a width direction D3. The depth direction D1 is also the vertical direction (up-down direction, height direction), and the length direction D2 and width direction D3 are also horizontal directions. The depth direction D1, length direction D2, and width direction D3 are perpendicular to one another.

[0012] The packaging box 1 of this embodiment has a rectangular parallelepiped shape. The packaging box 1 has four vertical surface portions 11, 12 arranged along a depth direction D1 and four horizontal surface portions 13, 14 arranged along horizontal directions (length direction D2 and width direction D3). All of these surface portions 11 to 14 have a rectangular shape.

[0013] The vertical surface portions 11, 12 are subdivided into a pair of long surface portions 11 arranged along the depth direction D1 and the length direction D2, and a pair of short surface portions 12 arranged along the depth direction D1 and the width direction D3. The pair of long surface portions 11 are arranged spaced apart from each other in the width direction D3, and the pair of short surface portions 12 are arranged spaced apart from each other in the length direction D2. These vertical surface portions 11, 12 form a rectangular cylindrical shape. The dimensions of the vertical surface portions 11, 12 in the depth direction D1 are equal to each other. The dimension of the long surface portion 11 in the length direction D1 is also greater than the dimension of the short surface portion 12 in the width direction D3. However, the various dimensions of the vertical surface portions 11, 12 are not limited to those exemplified here.

[0014] The horizontal surface portions 13, 14 are subdivided into a pair of top surface portions 13 each connected to the upper edges of the pair of long surface portions 11, and a pair of bottom surface portions 14 each connected to the lower edges of the pair of long surface portions 11. The pair of top surface portions 13 are each bent from the pair of long surface portions 11 in directions approaching each other and are arranged on the same plane. Similarly, the pair of bottom surface portions 14 are each bent from the pair of long surface portions 11 in directions approaching each other and are arranged below the pair of top surface portions 13 and on the same plane.

[0015] The long surface portion 11 and the top surface portion 13 (two surfaces) that are connected to each other are bent along the boundary line between them to form a corner portion 31. Similarly, the long surface portion 11 and the bottom surface portion 14 (two surfaces) that are connected to each other are bent along the boundary line between them to form a corner portion 32. Hereinafter, the corner 31 formed by the long surface portion 11 and the top surface portion 13 is also referred to as the "upper corner 31," and the corner 32 formed by the long surface portion 11 and the bottom surface portion 14 is also referred to as the "lower corner 32." Furthermore, the upper corner 31 and the lower corner 32 are also collectively referred to as the "corner 3." In this embodiment, the corners 3 are all approximately right angles.

[0016] 2 is a side view of the packaging box 1 in the middle of assembly as seen from the width direction D3, showing the state before the top surface 13 is folded from the long surface 11. As shown in FIG. 2, the packaging box 1, which is an A-type box, further has a pair of top inner surfaces 15 connected to the upper edges of the pair of short surface portions 12, and a pair of bottom inner surfaces 16 connected to the lower edges of the pair of short surface portions 12, respectively.

[0017] The pair of top inner surfaces 15 are folded from the pair of short surface portions 12 in directions approaching each other and then arranged horizontally. Then, the top surface portion 13 is placed over the top inner surfaces 15. Similarly, the pair of bottom inner surfaces 16 are folded from the pair of short surface portions 12 in directions approaching each other and then arranged horizontally. Then, the bottom surface portion 14 is placed over the bottom inner surfaces 16. Therefore, in the assembled packaging box 1 (see FIG. 1 ), the top surface portion 13 and the bottom surface portion 14 cover the top inner surfaces 15 and the bottom inner surfaces 16, respectively.

[0018] In this embodiment, corrugator creases 4 that guide folding are provided at the boundary between the long surface portion 11 and the top surface portion 13 and at the boundary between the short surface portion 12 and the top inner surface portion 15. Similarly, corrugator creases 4 are provided at the boundary between the long surface portion 11 and the bottom surface portion 14 and at the boundary between the short surface portion 12 and the bottom inner surface portion 16. The corrugator creases 4 are creases (grooves) processed on the surface (inner surface) that will become the inside of the packaging box 1. The long surface portion 11 and the top surface portion 13 are folded along the corrugator creases 4 provided at the boundary between them to form the upper corner portion 31. Similarly, the long surface portion 11 and the bottom surface portion 14 are folded along the corrugator creases 4 provided at the boundary between them to form the lower corner portion 32.

[0019] As shown in FIG. 1, a strip-shaped band 7 is wrapped around the packaging box 1. The band 7 is a so-called PP band made of plastic. The band 7 is arranged to fasten the long surface portion 11, the top surface portion 13, and the bottom surface portion 14 from the outside, and prevents the top surface portion 13 and the bottom surface portion 14 from being unintentionally opened. Note that FIG. 1 illustrates a packaging box 1 wrapped with two bands 7, but the number of bands 7 wrapped around the packaging box 1 is not particularly limited. Furthermore, instead of a configuration in which a band 7 is wrapped around one packaging box 1 as in this embodiment, a common band 7 may be wrapped around multiple packaging boxes 1, thereby integrating the multiple packaging boxes 1.

[0020] The packaging box 1 has a ridge line 5 that extends along the boundary line (i.e., corrugator crease 4) between the two surfaces at a corner 3 formed by the two surfaces, and a slit 6 that is cut in a convex shape from the ridge line 5 at one of the two surfaces that form the corner 3. In this embodiment, since the corner 3 includes an upper corner 31 and a lower corner 32, the ridge line 5 includes an upper ridge line 51 and a lower ridge line 52, and the slit 6 includes an upper slit 61 and a lower slit 62.

[0021] The upper ridge line 51 extends on the boundary line between the long surface portion 11 and the top surface portion 13. On the other hand, the lower ridge line 52 extends on the boundary line between the long surface portion 11 and the bottom surface portion 14. In this embodiment, all of the ridge lines 5 extend linearly along the longitudinal direction D2 and overlap with the corrugator creases 4.

[0022] The upper slit 61 is cut in a convex shape from the upper ridge line 51 on either the long surface portion 11 or the top surface portion 13. The upper slit 61 in this embodiment is provided on the top surface portion 13, but not on the long surface portion 11. On the other hand, the lower slit 62 is cut in a convex shape from the lower ridge line 52 on either the long surface portion 11 or the bottom surface portion 14. The lower slit 62 in this embodiment is provided on the bottom surface portion 14, but not on the long surface portion 11. As such, the slits 6 in this embodiment are all provided on the horizontal surface portions 13, 14, but not on the vertical surface portions 11, 12.

[0023] Here, an example is shown in which two upper slits 61 are provided for each upper ridge line 51 at an interval in the length direction D2, and two lower slits 62 are provided for each lower ridge line 52 at an interval in the length direction D2. The upper slits 61 and the lower slits 62 are formed at positions corresponding to each other. Specifically, the positions of the upper slits 61 and the lower slits 62 are aligned with each other in the length direction D2. A belt 7 overlaps the outside of each slit 6.

[0024] The number and arrangement of the slits 6 may be appropriately determined depending on the number and arrangement of the bands 7 wound around the packaging box 1. For example, in a packaging box 1 around which one band 7 is wound, one upper slit 61 may be provided near the center of each upper ridge line 51 in the length direction D2, and one lower slit 62 may be provided near the center of each lower ridge line 52 in the length direction D2. Furthermore, in two upper and lower packaging boxes 1 integrated with at least one band 7, at least one upper slit 61 may be provided for each upper ridge line 51 of the upper packaging box 1, and at least one lower slit 62 may be provided for each lower ridge line 52 of the lower packaging box 1. In other words, in this case, the lower slit 62 may be omitted from the upper packaging box 1, and the upper slit 61 may be omitted from the lower packaging box 1.

[0025] Fig. 3 is a plan view showing the periphery of the slit 6 when the two surfaces forming the corner 3 are arranged along the same plane. Fig. 3 and Figs. 4 and 5 described below illustrate an upper slit 61 when the long surface 11 and the top surface 13 are arranged along the same plane, but the lower slit 62 is also formed in a similar manner (vertically symmetrical). Note that in Figs. 3 to 5, the top surface 13 is not bent from the long surface 11, so the portion corresponding to the upper ridge line 51 is shown with a virtual line.

[0026] As shown in FIG. 3, the slit 6 is a linear cut formed in at least one of the two surfaces forming the corner 3. Both end portions 6a of the slit 6 overlap the ridge line 5. Furthermore, the middle portion 6b connecting the both end portions 6a of the slit 6 defines a protruding portion 8 together with the ridge line 5. The protruding portion 8 is a flap-shaped portion separated by the slit 6 in at least one of the two surfaces forming the corner 3. The protruding portion 8 bends toward the inside of the packaging box 1 when a tightening force is applied from the belt 7.

[0027] The slit 6 in this embodiment is cut in a parenthetical shape (arc shape) that convexly extends from the ridge line 5 on one of the two surfaces that form the corner 3. Here, an upper slit 61 is shown as an example, cut in a parenthetical shape that convexly extends from the upper ridge line 51 on the top surface 13. The lower slit 62 is cut in a parenthetical shape that convexly extends from the lower ridge line 52 on the bottom surface 14. The convex portion 8 defined by the parenthetical slit 6 and the ridge line 5 forms a bow shape surrounded by the arc described by the slit 6 and the chord described by the ridge line 5.

[0028] However, the shape of the slit 6 is not limited to the round bracket shape as described above. For example, as shown in Fig. 4, the slit 6 may be cut into a tortoiseshell-shaped shape that protrudes from the ridge line 5 on one of the two surfaces forming the corner 3. The tortoiseshell-shaped slit 6 has a parallel portion 6c that extends linearly parallel to the ridge line 5, and a pair of slanted portions 6d that extend obliquely from both ends of the parallel portion 6c to the ridge line 5 so as to be spaced apart. The protrusion 8 defined by such tortoiseshell-shaped slit 6 and the ridge line 5 forms a trapezoid in which the slit 6 corresponds to the upper base and legs and the ridge line 5 corresponds to the lower base.

[0029] Alternatively, as shown in Fig. 5, the slit 6 may be cut in a wave-like shape. The wave-like slit 6 has a parenthesized main portion 6e that protrudes from the ridge line 5 on one of the two surface portions forming the corner portion 3, and a pair of parenthesized auxiliary portions 6f that are connected to both ends of the main portion 6e and that protrude from the ridge line 5 on the other of the two surface portions. Fig. 5 shows an example of an upper slit 61 that has a parenthesized main portion 6e that protrudes from the upper ridge line 51 on the top surface portion 13, and a pair of parenthesized auxiliary portions 6f that protrude from the upper ridge line 51 on the long surface portion 11.

[0030] The protrusions 8 defined by such wave-shaped slits 6 and ridge lines 5 include a main protrusion 8a defined by the main portion 6e and ridge line 5, and a pair of auxiliary protrusions 8b defined by the auxiliary portion 6f and ridge line 5. The main protrusion 8a forms a bow shape surrounded by the arc described by the main portion 6e and the chord described by the ridge line 5. Furthermore, each auxiliary protrusion 8b forms a bow shape surrounded by the arc described by the auxiliary portion 6f and the chord described by the ridge line 5. Figure 5 shows an example of a slit 6 in which the dimension of the main portion 6e is larger than the dimension of each auxiliary portion 6f in the length direction D2, which is the extension direction of the ridge line 5.

[0031] [1-2. Sheet material] The packaging box 1 of this embodiment is formed from one sheet material 2 shown in Fig. 6. Here, the sheet material 2 is a cardboard sheet as an example. Below, the configuration of the sheet material 2 will be described assuming that the sheet material 2 extends along a plane. In other words, the sheet material 2 described below corresponds to the state in which the packaging box 1 is unfolded into a plane.

[0032] In the following description, a horizontal direction Dx and a vertical direction Dy are defined as directions relating to the sheet material 2. The horizontal direction Dx and the vertical direction Dy are perpendicular to each other in the plane in which the sheet material 2 extends. In the sheet material 2 assembled into an A-type cardboard box, the hollow portion formed by the corrugated core of the cardboard sheet extends along the vertical direction Dy.

[0033] In the sheet material 2, four panels 21, 22 are arranged in the horizontal direction Dx, and flaps 23 to 26 are provided to protrude from both sides of the panels 21, 22 in the vertical direction Dy. Vertical surface portions 11, 12 of the packaging box 1 are formed by the panels 21, 22 of the sheet material 2. Furthermore, horizontal surface portions 13, 14 of the packaging box 1 are formed by the flaps 23 to 26 of the sheet material 2.

[0034] The panels 21, 22 are further divided into a pair of long panels 21 that form the long surface portions 11 of the packaging box 1, and a pair of short panels 22 that form the short surface portions 12 of the packaging box 1. The flaps 23 to 26 are further divided into four outer flaps 23, 24 that form the top surface portion 13 and the bottom surface portion 14 of the packaging box 1, and four inner flaps 25, 26 that form the top inner surface portion 15 and the bottom inner surface portion 16 of the packaging box 1. The outer flaps 23, 24 protrude from both sides of the long panel 21 in the longitudinal direction Dy, and the inner flaps 25, 26 protrude from both sides of the short panel 22 in the longitudinal direction Dy.

[0035] In this embodiment, a sheet material 2 is illustrated in which one long panel 21, one short panel 22, the other long panel 21, and the other short panel 22 are arranged in this order from one side to the other in the horizontal direction Dx (from left to right in FIG. 6). A bonding piece 27 is connected to one long panel 21 to connect the one long panel 21 to the other short panel 22 when the sheet material 2 is assembled into a packaging box 1. The bonding piece 27 protrudes from the one long panel 21 to one side in the horizontal direction Dx (in a direction away from the one short panel 22).

[0036] In the sheet material 2, corrugator creases 4 that define the boundary between the panels 21, 22 and the flaps 23 to 26 extend along the horizontal direction Dx. In addition, the sheet material 2 has vertical creases 9 that define the boundary between the panels 21, 22 and the bonding piece 27, extending along the vertical direction Dy. The vertical creases 9 are creases (grooves) similar to the corrugator creases 4, and serve to guide folding when the sheet material 2 is assembled into a packaging box 1. However, in sheet materials 2 that are assembled into A-type boxes, the corrugator creases 4 are processed more strongly (deeper) than the vertical creases 9. The sheet material 2 is assembled so that the processed surface of the corrugator creases 4 and the vertical creases 9 faces the inside (inner surface) of the packaging box 1. In other words, both the corrugator creases 4 and the vertical creases 9 are processed for inward folding.

[0037] The slits 6 are cut in a convex shape from the corrugator crease 4 toward at least one side in the longitudinal direction Dy. Here, parenthesized slits 6 that convex from the corrugator crease 4 toward the outside in the longitudinal direction Dy are shown as an example in the outer flaps 23, 24. As such, the slits 6 in this embodiment are provided in the outer flaps 23, 24, and not in the panels 21, 22.

[0038] [2. Actions and Effects] (1) In the packaging box 1, a slit 6 is provided that is cut in a convex shape from the ridge line 5 of the corner 3 formed by the two surfaces. This allows the convex portion 8 surrounded by the slit 6 and the ridge line 5 to swing freely. As a result, as shown in FIG. 7 , when a tightening force is applied to the packaging box 1 from the band 7 wrapped around the outside of the slit 6, the convex portion 8 on one of the two surfaces that form the corner 3 overlaps with another portion. This ensures that the corner 3 can be folded diagonally (at an obtuse angle). In the packaging box 1 of this embodiment, the convex portion 8 surrounded by the upper slit 61 and the upper ridge line 51 overlaps with another portion on the top surface 13, causing the upper corner 31 to bend diagonally. While FIG. 7 illustrates the upper corner 31 of the packaging box 1, the lower corner 32 is similar (vertically symmetrical).

[0039] In this way, the swingable protrusion 8 overlaps with other parts to form a slope at the corner 3, thereby preventing the band 7 from biting into the corner 3. This more reliably prevents damage to the corner 3 due to the band 7 biting into it. In FIG. 7, the two edges separated by the upper slit 61 are each marked with the symbol "61(6)."

[0040] (2) In general, when an A-type box is unfolded, the corrugator crease 4, which forms the boundary between the panels 21, 22 and the flaps 23 to 26, is deeper than the other creases, making it difficult to fold any part other than the corrugator crease 4. In contrast, the packaging box 1 is provided with the slits 6, so even if the ridge line 5 of the corner 3 formed by the long surface portion 11 and the horizontal surface portions 13, 14 overlaps with the corrugator crease 4, the convex portion 8 surrounded by the slits 6 and the ridge line 5 overlaps with other parts, as described above, so that the corner 3 can be reliably folded diagonally. Therefore, even in the A-type packaging box 1, damage to the corner 3 due to the band 7 digging in can be more reliably prevented.

[0041] (3) By providing upper slits 61 cut convexly from the upper ridge line 51 on either the long surface portion 11 or the top surface portion 13, and lower slits 62 cut convexly from the lower ridge line 52 on either the long surface portion 11 or the bottom surface portion 14, both the upper corners 31 and the lower corners 32 can be reliably folded diagonally. Therefore, damage to both the upper corners 31 and the lower corners 32 due to the band 7 biting into them can be more reliably prevented.

[0042] (4) If the slits 6 are provided on the vertical surfaces 11 and 12, there is a risk of a decrease in the compressive strength of the packaging box 1 in the depth direction D1. In contrast, if the slits 6 are provided on the horizontal surfaces 13 and 14 but not on the vertical surfaces 11 and 12, it is possible to maintain the compressive strength of the packaging box 1 in the depth direction D1 while suppressing damage to the corners 3 due to the bands 7 biting into them. Therefore, it is possible to prevent a decrease in the reliability of the packaging box 1.

[0043] (5) As shown in Figure 3, the slit 6 is cut in a round bracket shape that protrudes from the ridge 5, and the entire slit 6 forms a curve, which makes it easier to avoid stress concentration. This further reduces damage to the corner 3 due to the band 7 biting into it.

[0044] (6) As shown in Fig. 4, the slits 6 cut in a tortoiseshell shape protruding from the ridge line 5 make it easier to ensure the size of the protrusions 8 surrounded by the slits 6 and the ridge line 5 in the direction of extension of the ridge line 5 (the length direction D2 in this embodiment). This makes it possible to more reliably prevent damage to the corners 3 due to the band 7 biting into them in the direction of extension of the ridge line 5.

[0045] (7) As shown in Figure 5, the slit 6 cut in a wave shape has a parenthesized main portion 6e that protrudes from the ridge line 5 on one of the two surfaces forming the corner 3, and a pair of parenthesized auxiliary portions 6f that protrude from the ridge line 5 on the other of the two surfaces. Therefore, the main protrusion 8a surrounded by the main portion 6e and the ridge line 6f overlaps with other portions, ensuring that the corner 3 can be folded diagonally. At the same time, the pair of auxiliary portions 6f distributes the fastening force from the band 7, mitigating stress concentration at both ends of the main portion 6e. This further reduces damage to the corner 3 due to the band 7 biting into it.

[0046] [3. Modifications] The above-described arrangement of the slits 6 is one example. The slits 6 may be cut in a convex shape from a ridge line extending on the boundary line between two surfaces forming a corner of the packaging box 1. For example, the slits 6 may be cut in a convex shape from a ridge line extending on the boundary line between the long surface 11 and the short surface 12 forming the corner. That is, the slits 6 are not limited to a ridge line extending horizontally in the packaging box 1, but may also be cut in a convex shape from a ridge line extending in the depth direction D1. In either case, a packaging box 1 having the slits 6 can more reliably prevent damage to the corners due to the band 7 wrapped around the outside of the slits 6 biting into it, as described above.

[0047] The slits 6 may be provided on the long surface portions 11, and may not be provided on the top surface portion 13 or the bottom surface portion 14. Alternatively, the slits 6 may be provided across the long surface portions 11 and the top surface portion 13 or the bottom surface portion 14, as in the wave-shaped slits 6 illustrated in FIG.

[0048] The packaging box 1 may be formed of a sheet material other than a corrugated cardboard sheet. Furthermore, the packaging box 1 is not limited to the above-described type A box. As shown in FIG. 8, the packaging box 1 may be formed of a main body sheet piece 2A that is assembled to a tray-shaped (square cylindrical with a bottom) main body, and a lid sheet piece 2B that is assembled to a lid that covers the main body. In the modified example shown in FIG. 8, both the main body sheet piece 2A and the lid sheet piece 2B are made of corrugated cardboard sheets.

[0049] The main body sheet piece 2A has a rectangular bottom panel 44 that becomes the bottom surface (horizontal surface) when assembled to the main body, and four rectangular side panels 41, 42 that become side surfaces (vertical surface portions) when assembled. The side panels 41, 42 are subdivided into a pair of first side panels 41 that face each other when assembled, and a pair of second side panels 42 that face each other when assembled and are arranged at right angles to the first side panel 41.

[0050] In the assembled state, the side panels 41, 42 are folded up from the bottom panel 44, so that the bottom panel 44 and each side panel 41, 42 form corners (lower corners). Therefore, the boundary lines 45 between the bottom panel 44 and each side panel 41, 42 become ridge lines (lower ridge lines) in the assembled state. In this modified example, the bottom panel 44 is provided with slits 6 (lower slits 62) that are cut in a convex shape from the boundary lines 45 between the bottom panel 44 and each first side panel 41.

[0051] The lid sheet piece 2B has a rectangular top panel 43 that becomes the top surface (horizontal surface) when assembled to the lid, and a pair of rectangular overlapping panels 46 that become side surfaces (vertical surfaces) when assembled. In the assembled state, the overlapping panels 46 are folded down from the top panel 43, so that the top panel 43 and each overlapping panel 46 form corners (upper corners). Therefore, the boundary line 47 between the top panel 43 and each overlapping panel 46 becomes a ridge line (upper ridge line) when assembled. In this modified example, the top panel 43 has a slit 6 (upper slit 61) that is cut in a convex shape from the boundary line 47 between the top panel 43 and each overlapping panel 46.

[0052] In the packaging box formed of the main body sheet piece 2A and the lid sheet piece 2B of this modified example, the top panel 43 is disposed above the side panels 41, 42 so as to face the bottom panel 44, and a pair of overlapping panels 46 are placed on the outside of the pair of first side panels 41. Since the slit 6 is provided in this packaging box as well, similar to the above embodiment, the corners can be reliably folded diagonally (at an obtuse angle) when a tightening force is applied from a band wrapped around the outside of the slit 6. Therefore, damage to the corners due to the band 7 biting into them can be more reliably prevented. Furthermore, the packaging box of this modified example achieves the same functions and effects as the above embodiment, due to the same configuration. [Explanation of symbols]

[0053] 1 packaging box 2 Sheet material 2A Main body sheet piece 2B Lid sheet piece 3 Corner 4 Corrugator Crease 5 Ridgeline 6 Slits 6a Both ends 6b Middle part 6c Parallel part 6d Oblique 6e Main part 6f Auxiliary part 7 bands 8 Convex part 8a Main convex part 8b Auxiliary protrusion 9 Vertical lines 11 Long surface (vertical surface) 12 Short surface (vertical surface) 13 Top section (horizontal section) 14 Bottom part (horizontal part) 15 Top surface 16 Bottom inner surface 21 Long Panel (Panel) 22 Short Panel (Panel) 23,24 Outer flap (flap) 25,26 Inner flap (flap) 27 Pasting piece 31 Upper corner 32 Lower corner 41 First side panel 42 Second side panel 43 Top panel 44 Bottom Panel 45 Borderline 46 Polymerized Panel 47 Borderline 51 Upper Ridge 52 Lower Ridge 61 Upper slit 62 Lower slit D1 Depth direction (vertical direction) D2 Length direction (horizontal direction) D3 width direction (horizontal direction) Dx horizontal direction Dy Vertical direction

Claims

1. A packaging box in which two connected surfaces are folded along a boundary line to form a corner, a ridge line extending on the boundary line at the corner; a slit cut in a convex shape from the ridge line on one of the two surfaces; a flap-shaped convex portion defined by the ridge line and the slit; A packaging box characterized by:

2. An A-type box having, when unfolded in a plane, four panels arranged in a horizontal direction, flaps protruding from both sides of the panels in a vertical direction, and corrugator creases forming boundary lines between the panels and the flaps extending along the horizontal direction, the two surface portions are a vertical surface portion disposed along the vertical direction and formed by the panel, and a horizontal surface portion disposed along the horizontal direction and formed by the flap, The ridge line overlaps with the corrugator crease.

2. The packaging box according to claim 1.

3. the two surface portions are a vertical surface portion disposed along the vertical direction and a horizontal surface portion disposed along the horizontal direction, The horizontal surface portion includes a top surface portion connected to an upper edge of the vertical surface portion and a bottom surface portion connected to a lower edge of the vertical surface portion, the ridge line includes an upper ridge line extending on a boundary line between the vertical surface portion and the top surface portion, and a lower ridge line extending on a boundary line between the vertical surface portion and the bottom surface portion, The slits include upper slits cut in a convex shape from the upper ridge line on either the vertical surface portion or the top surface portion, and lower slits cut in a convex shape from the lower ridge line on either the vertical surface portion or the bottom surface portion.

3. The packaging box according to claim 1 or 2.

4. the two surface portions are a vertical surface portion disposed along the vertical direction and a horizontal surface portion disposed along the horizontal direction, The slits are provided on the horizontal surface portion and not on the vertical surface portion. The packaging box according to any one of claims 1 to 3.

5. The slit is cut in a round bracket shape that protrudes from the ridge line on one of the two surfaces. The packaging box according to any one of claims 1 to 4.

Images