Packaging cartons

Abstract

To provide a paper packaging box which has a double-wall structure with a frame, but reinforces the strength of the corners of the box, and can be manufactured by an automatic box-making device. [Solution] The paper packaging box 1 of the present invention has four extension portions 50LB that extend from both the front and rear sides 123SLB of the left and right inner walls 23L, using these sides 123SLB as fold lines. The extension portions 50LB are folded toward the back side at the fold line at the boundary 123SLB between the left and right inner walls 23L and the inner wall opposing portion 51LB and the fold line at the boundary 53DLB between the front and rear outer wall attachment portion 54LB and the outer wall opposing portion 53LB, respectively. The extension portions 50LB are also folded toward the front side at the parallel fold lines 52D1LB, 52D2LB on both sides of the side wall intervening portion 52LB, and exist between the front and rear outer walls 31B and the front and rear inner walls 33B, so that the side wall intervening portion 52LB functions as a spacer between the front and rear outer walls 31B and the front and rear inner walls 33B.

Description

[Technical Field]

[0001] The present invention relates to a packaging carton, and in particular to a double-walled packaging carton with a so-called frame. [Background technology]

[0002] Conventionally, there are paper packaging boxes that are formed into a tray shape by folding four side walls connected to a rectangular bottom plate. In order to protect the contents and give the box a luxurious and heavy appearance, the side walls have a double-wall structure consisting of inner and outer walls, and the inner and outer walls have frames at their upper ends (see, for example, Patent Document 1 and Patent Document 2).

[0003] Such framed double-walled paper packaging boxes are often designed for manual assembly, making them difficult to manufacture using box-making machines. Furthermore, attempts to manufacture them using box-making machines often result in loose corners and deformation. For this reason, various innovations have been made, but no paper packaging box has been developed that combines high corner strength with high productivity. For example, Patent Document 1 discloses a technology in which a rattle-preventing flap, slightly narrower than the frame width P, is completely embraced by the frame, side walls, and inner walls to prevent movement, and a protrusion on the tip of the inner wall is inserted into an opening in both adjacent inner walls to lock it in place. The technology described in Patent Document 1 is said to provide a framed double-walled paper box that can be easily assembled without adhesives or other adhesives and prevents loose corners. Patent Document 2 also discloses a box-making machine for boxes with frame pieces. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2006-282265 [Patent Document 2] Patent Publication No. 2021-008064 Summary of the Invention [Problem to be solved by the invention]

[0005] However, when attempting to manufacture boxes using an automatic box-making machine to increase productivity, rattles tend to form at the corners of the boxes, and the boxes tend to lose their shape. Therefore, gluing the flaps is an option, but the box manufacturing process is basically unidirectional, and the areas to be glued need to extend in one direction. For example, in the framed paper double box described in Patent Document 1, even if you try to glue the inner wall tip flaps (reference numerals 14 to 17) that extend in two perpendicular directions, you cannot glue them efficiently, and it is difficult to increase productivity by using an automatic box-making machine for the framed paper double box described in Patent Document 1.

[0006] Furthermore, in Patent Documents 1 and 2, there is a cavity between the inner and outer walls of the frame, and it is difficult to fix this gap, so even if you try to attach a flap to the frame, it is not sufficiently attached, and it is difficult to maintain a stable shape in a double-walled packaging paper box with a frame. Even if you try to glue the inner wall by providing some kind of separate reinforcing member between the inner and outer walls, it will not be stable due to the cavity between the inner and outer walls, and it will also be difficult to attach the reinforcing member to the inner wall, especially when manufacturing using an automatic box-making machine.

[0007] Therefore, an object of the present invention is to provide a paper packaging box that has a framed double-wall structure, but has reinforced corner strength, and can be manufactured using an automatic box-making machine. [Means for solving the problem]

[0008] The above object can be achieved by the following aspects of the present invention. That is, the aspects of the present invention are as follows. <1> A paper packaging box comprising a rectangular bottom plate having four edges on the left, right, front and rear sides, and four side walls extending from the left, right and front and rear edges of the bottom plate, and which is open at the top, and which is formed by folding and pasting a sheet-like unfolded body having a single front and back surface, so that the surface of the unfolded body becomes the inner surface of the bottom plate, The left and right side walls each have left and right outer walls connected to the bottom plate, left and right inner walls facing the left and right outer walls, left and right upper walls connecting the left and right outer walls and the left and right inner walls at their upper sides, and left and right bottom plate attachment portions connected to the lower sides of the left and right inner walls and facing the inner surface of the bottom plate, extending in a direction away from the left and right outer walls and attached to the inner surface of the bottom plate, the front and rear side walls each include a front and rear outer wall connected to the bottom plate, a front and rear inner wall facing the front and rear outer wall, and a front and rear upper wall connecting the front and rear outer wall and the front and rear inner wall at an upper side, The deployment body is a bottom plate equivalent portion corresponding to the bottom plate; Left and right outer wall equivalent portions corresponding to the left and right outer walls and connected to the left and right edges of the bottom plate equivalent portion as fold lines; Left and right upper wall equivalent portions corresponding to the left and right upper walls and connected to the left and right of the left and right outer wall equivalent portions with boundaries as fold lines; Left and right inner wall equivalent portions corresponding to the left and right inner walls and connected to the left and right of the left and right upper wall equivalent portions with boundaries as fold lines; Left and right bottom plate attaching portions corresponding to the left and right bottom plate attaching portions, which are connected to the left and right of the left and right inner wall corresponding portions with the boundaries as fold lines and extend in the front-to-rear direction; A front and rear outer wall equivalent portion corresponding to the front and rear outer walls and connected to the front and rear edges of the bottom plate equivalent portion as fold lines; A front and rear upper wall equivalent portion corresponding to the front and rear upper wall and connected to the front and rear of the front and rear outer wall equivalent portion with the boundary as a fold line; Front and rear inner wall equivalent portions corresponding to the front and rear inner walls and connected to the front and rear of the front and rear upper wall equivalent portions with boundaries as fold lines; The left and right sides of the left and right outer wall equivalent parts and the left and right sides of the front and rear outer wall equivalent parts are connected as fold lines, and the corners of the edges of the bottom plate equivalent parts are used as base points to divide the parts at an angle of 45°. Four connecting parts, Four extension portions extending from both the front and rear sides of the left and right inner wall corresponding portions, using these sides as fold lines; Equipped with In the deployed body, each of the extension portions comprises an inner wall opposing portion connected to the left and right inner wall equivalent portions, a side wall intervening portion connected to the inner wall opposing portion and perpendicular to the extension line of the dividing line of the adjacent connecting portion, and sandwiched between two fold lines spaced at a distance substantially the same as or slightly narrower than the distance between the front and rear outer walls and the front and rear inner walls, an outer wall opposing portion connected to the side wall intervening portion, and front and rear outer wall attaching portions connected to the outer wall opposing portion at a fold line that is on the same line as or parallel to the fold line between the adjacent left and right inner wall equivalent portions and the left and right bottom plate attaching portion equivalent portions, and extending on the extension line of the position where the adjacent left and right bottom plate attaching portions extend, the four side walls are erected from the bottom plate by folding along fold lines between the bottom plate equivalent and the left and right outer wall equivalents, between the left and right outer wall equivalents and the left and right upper wall equivalents, between the left and right upper wall equivalents and the left and right inner wall equivalents, between the bottom plate equivalent and the front and rear outer wall equivalents, between the front and rear outer wall equivalents and the front and rear upper wall equivalents, and between the front and rear upper wall equivalents and the front and rear inner wall equivalents, and along fold lines at the attachment portion boundaries to the back side, the left and right bottom plate attachment portions and the front and rear outer wall attachment portions are attached to the positions of the bottom plate equivalent portions and the rear outer wall equivalent portions that come into contact when the deployed body is folded back to the front surface along the fold lines between the left and right outer wall equivalent portions and the left and right upper wall equivalent portions, The front and rear inner wall corresponding portions are attached to the inner wall opposing portions of the adjacent extension portions with regions in the vicinity of both the front and rear left and right sides thereof as glue tabs, The extension portions are folded toward the back side at the fold lines at the boundaries between the left and right inner wall corresponding portions and the inner wall opposing portions and the fold lines at the boundaries of the pasted portions, and are present between the front and rear outer walls and the front and rear inner walls in a state where they are folded toward the front side at parallel fold lines on both sides of the side wall intervening portion, the connecting portion is folded toward the front surface at the fold lines of the boundaries between the front and rear outer wall corresponding portions and the left and right outer wall corresponding portions, and is folded back toward the back surface at the dividing line, and is surrounded by the inner wall opposing portion, the side wall intervening portion, and the outer wall opposing portion in the extension portion, The paper packaging box, wherein the side wall intervening portions function as spacers between the front and rear outer walls and the front and rear inner walls.

[0009] <2> The left-right position of the boundary of the attachment portion is located on the side farther from the side wall interposition portion than the folding line between the left-right inner wall corresponding portion and the left-right bottom plate attachment corresponding portion. <1> The packaging paper box described in .

[0010] <3> In the deployable body, each of the connecting portions is provided with a protruding piece protruding from a side opposite to a boundary between the left and right outer wall equivalent portions, and the side opposite to the boundary between the left and right outer wall equivalent portions is a fold line, The protruding pieces are folded back at fold lines at the boundaries between the left and right inner wall portions and abut against the lower surfaces of the front and rear upper walls. <1> The packaging paper box described in .

[0011] <4> At least a portion of the contact surface of each of the protruding pieces with the lower surface of the front and rear upper wall is attached. <3> The packaging paper box described in .

[0012] <5> The left and right inner walls and the front and rear inner walls are lower than the left and right outer walls and the front and rear outer walls. <1> The packaging paper box described in . [Effects of the Invention]

[0013] According to the present invention, it is possible to provide a paper packaging box that has a framed double-wall structure, but has reinforced corner strength, and can be manufactured using an automatic box-making machine. [Brief explanation of the drawings]

[0014] [Figure 1] 1 is a perspective view of a paper packaging box according to a first embodiment which is an exemplary aspect of the present invention. FIG. [Figure 2] FIG. 1 is a plan view showing an unfolded paper packaging box according to a first embodiment. [Figure 3] 3 is a plan view of the deployable body 101' shown in FIG. 2 in a state where the deployable body is folded back to the front side along the folding lines of boundaries 121DL and 121DR. FIG. [Figure 4] FIG. 4 is a partially enlarged perspective view of the connecting portion 40LB, the extension portion 50LB, and their surroundings, showing the state in which they are being folded from the deployed body shown in FIG. 3 toward the front side along the fold line between the bottom plate equivalent portion 110 and the rear outer wall equivalent portion 131B (edge 11B). [Figure 5] FIG. 4 is a partially enlarged perspective view of the connecting portion 40LB, the extension portion 50LB, and their surroundings, showing the state in which the deployed body shown in FIG. 3 is folded up toward the front side along the fold line between the bottom plate equivalent portion 110 and the rear outer wall equivalent portion 131B (edge 11B). [Figure 6] 2 is an enlarged cross-sectional view of the CC section in FIG. 1, showing a state in which a rear wall and a left wall are erected from the bottom plate. [Figure 7] FIG. 6 is a partially enlarged perspective view of a typical framed double-walled paper packaging box in the middle of being assembled, at the same stage as in FIG. 5, and from the same position and angle. [Figure 8] FIG. 11 is a partially enlarged perspective view of the connecting portion 40LB, the extension portion 50LB, and their surroundings, showing the state in which the unfolded body of the packaging paper box according to the modified example has been folded up toward the front side along the fold line between the bottom plate equivalent portion 110 and the rear outer wall equivalent portion 131B (edge 11B). [Figure 9] FIG. 1 is a perspective view of a paper packaging box according to a second embodiment which is an exemplary aspect of the present invention. [Figure 10] FIG. 10 is a plan view showing an unfolded paper packaging box according to the second embodiment. [Figure 11] FIG. 10 is a partially enlarged cross-sectional view of the paper packaging box according to the second embodiment, taken along the line FF in FIG. 9. [Figure 12] FIG. 11 is a partially enlarged perspective view of the connecting portion 40′LB, the extension portion 50LB, and their surroundings, showing the state in which they are being folded from the deployed body shown in FIG. 10 toward the front side along the fold line between the bottom plate equivalent portion 160 and the rear outer wall equivalent portion 181B (edge 61B). DETAILED DESCRIPTION OF THE INVENTION

[0015] Hereinafter, a paper packaging box according to an embodiment, which is one exemplary aspect of the present invention, will be described with reference to FIGS.

[0016] [First embodiment] Fig. 1 is a perspective view of a paper packaging box 1 according to the first embodiment. As shown in Fig. 1, the paper packaging box 1 according to this embodiment comprises a rectangular bottom plate 10 having four edges (11L, 11R, 11F, and 11B in the unfolded body 101 in Fig. 2, which will be described later) on the left, right, front, and rear sides, and four side walls 20L, 20R, 30F, and 30B erected from the left, right, front, and rear edges (same as above) of the bottom plate 10, and is open at the top.

[0017] In the present invention and this embodiment, the left-right, front-rear, and up-down directions are used to indicate relative positional relationships on the paper packaging box, and do not represent the left-right, front-rear, and up-down directions in actual manufacturing or use situations. Furthermore, the letter L at the end of the reference numeral attached to each component indicates the left component, R indicates the right component, F indicates the front component, and B indicates the rear component. Furthermore, when a component is attached with the letters LRFB indicating these positional relationships but does not have the letters LRFB indicating the positional relationships, it is considered to represent all of the left-right, front-rear, both the left and right, or both the front and rear. The rules for the alphabets and other elements used to indicate positional relationships apply not only to this embodiment but also to the modified examples and embodiments described below.

[0018] The paper packaging box 1 according to this embodiment is, in principle, symmetrical from left to right and from front to back, with the left and right side walls 20L, 20R, 30F, and 30B being symmetrical from left to right, and the front and rear side walls 30F, 30B being symmetrical from front to back, all having the same longitudinal length, i.e., the upper opening is square. When describing the left, right, and front / rear side walls individually, the left, right, and front / rear side walls are written with the word "side" (for walls other than the side walls) at the beginning to indicate their direction, such as left wall 20L, right wall 20R, front wall 30F, and rear wall 30B. This rule also applies to this embodiment, as well as to the modifications and embodiments described below.

[0019] Furthermore, when symmetrical left and right or front and rear side walls are represented as a set, the alphabets L, R, F, B indicating the positional relationship at the end of the reference numeral are removed and the set is represented as left and right side walls 20 or front and rear side walls 30 (they may also be represented without reference numerals (e.g., in the claims)). The same rule applies hereinafter to each part constituting the side walls 20L, 20R, 30F, 30B and to each corresponding part in the deployable body described later. This rule also applies to this embodiment as well as to the modified examples and embodiments described below.

[0020] The left and right side walls 20L, 20R (left and right side walls 20) each have left and right outer walls 21 continuing to the bottom plate 10, left and right inner walls 23 facing the left and right outer walls 21, left and right upper walls 22 connecting the left and right outer walls 21 and the left and right inner walls 23 at the upper side, and left and right bottom plate attachment portions 24 continuing to the lower sides of the left and right inner walls 23. The left and right bottom plate attachment portions 24 face the inner surface of the bottom plate 10 and extend in a direction away from the left and right outer walls 21, and are attached to the inner surface of the bottom plate 10.

[0021] The front and rear side walls 30F, 30B (front and rear side walls 30) each have a front and rear outer wall 31 continuing to the bottom plate 10, a front and rear inner wall 33 facing the front and rear outer wall 31, a front and rear upper wall 32 connecting the front and rear outer wall 31 and the front and rear inner wall 33 at the upper side, and a front and rear bottom plate facing portion 34 continuing to the lower side of the front and rear inner wall 33. The front and rear bottom plate facing portion 34 faces the inner surface of the bottom plate 10 and extends in a direction away from the front and rear outer wall 31.

[0022] FIG. 2 is a plan view showing the unfolded body 101 of the paper packaging box 1 according to the first embodiment. The plan view shown in FIG. 2 is generally referred to as a developed view. The paper packaging box 1 according to this embodiment is formed by folding and pasting a single sheet-like unfolded body 101 having a front and back surface, so that the front surface of the unfolded body 101 becomes the inner surface of the bottom plate 10. Note that in this invention and this embodiment, the front and back surfaces of the unfolded body 101 are expressions used to distinguish between paper surfaces and are unrelated to the so-called front and back surfaces of the paper itself. In this invention and this embodiment, the side that becomes the inner surface of the bottom plate 10 is the front surface, and corresponds to the surface shown in FIG. 2.

[0023] The unfolded body 101 of the paper packaging box 1 according to this embodiment includes a bottom plate equivalent portion 110 corresponding to the bottom plate 10, left and right outer wall equivalent portions 121 corresponding to the left and right outer walls 21, left and right upper wall equivalent portions 122 corresponding to the left and right upper walls 22, left and right inner wall equivalent portions 123 corresponding to the left and right inner walls 23, left and right bottom plate attaching portion equivalent portions 124 corresponding to the left and right bottom plate attaching portion 24, front and rear outer wall equivalent portions 131 corresponding to the front and rear outer walls 31, and left and right upper wall equivalent portions 132 corresponding to the front and rear upper walls 32. The panel is provided with front and rear upper wall equivalent portions 132, front and rear inner wall equivalent portions 133 corresponding to the front and rear inner walls 33, front and rear bottom plate opposing portions 134 corresponding to the front and rear bottom plate opposing portions 34, four connecting portions 40LB, 40LF, 40RB, 40RF connecting the left and right outer wall equivalent portions 121 and the front and rear outer wall equivalent portions 131 in the left and right, front and rear directions, and four extending portions 50LB, 50LF, 50RB, 50RF extending front and rear from the left and right inner wall equivalent portions 123.

[0024] When referring to all four connecting portions 40LB, 40LF, 40RB, and 40RF, the alphabetic characters are removed from the reference numerals and the reference numerals are written as "connecting portion 40." Similarly, when referring to all four extending portions 50LB, 50LF, 50RB, and 50RF, the alphabetic characters are removed from the reference numerals and the reference numerals are written as "extending portion 50." The same rules for the reference numerals apply to the respective portions constituting connecting portion 40 and extending portion 50, which will be described later. Furthermore, the same rules apply not only to this embodiment but also to the modified examples and embodiments described below.

[0025] The left and right outer wall equivalent portions 121 are connected to the left and right edges 11L, 11R of the bottom plate equivalent portion 110 as fold lines, the left and right upper wall equivalent portions 122 are connected to the left and right sides of the left and right outer wall equivalent portions 121 at left and right boundaries 121D, the left and right inner wall equivalent portions 123 are connected to the left and right sides of the left and right upper wall equivalent portions at left and right boundaries 122D, and the left and right bottom plate attachment equivalent portions 124 are connected to the left and right sides of the left and right inner wall equivalent portions 123 at left and right boundaries 123D. The left and right bottom plate attachment equivalent portions 124 extend in the front-to-rear direction.

[0026] The "fold lines" are formed by pressing or cutting into parts of the deployable body 101, and are formed to make it easier to fold the specified positions of the deployable body 101. After folding, the "fold lines" become so-called "creases."

[0027] The front and rear outer wall equivalent portions 131 are connected to the front and rear edges 11F, 11B of the bottom plate equivalent portion 110 as fold lines, the front and rear upper wall equivalent portions 132 are connected to the front and rear of the front and rear outer wall equivalent portions 131 as fold lines at the front and rear boundary 131D, the front and rear inner wall equivalent portions 133 are connected to the front and rear of the front and rear upper wall equivalent portions 132 as fold lines at the front and rear boundary 132D, and the front and rear bottom plate opposing portion equivalent portions 134 are connected to the front and rear of the front and rear inner wall equivalent portions 133 as fold lines at the front and rear boundary 133D.

[0028] In this embodiment, the widths of the left and right outer wall equivalent portions 121 (i.e., the left-right lengths of the left and right outer wall equivalent portions 121, symbol a in FIG. 2) and the widths of the front and rear outer wall equivalent portions 131 (i.e., the front-rear length of the front and rear outer wall equivalent portions 131, symbol c in FIG. 2) are approximately the same. Also, the widths of the left and right inner wall equivalent portions 123 (i.e., the left-right lengths of the left and right inner wall equivalent portions 123, symbol b in FIG. 2) and the widths of the front and rear inner wall equivalent portions 133 (i.e., the front-rear length of the front and rear inner wall equivalent portions 133, symbol d in FIG. 2) are approximately the same. Also, the widths (a) of the left and right outer wall equivalent portions 121 and the widths (b) of the left and right inner wall equivalent portions 123 are approximately the same, but strictly speaking, the former is longer by about the thickness of a piece of paper (α). Furthermore, the width (c) of the front and rear outer wall equivalent portion 131 and the width (d) of the front and rear inner wall equivalent portion 133 are also almost the same, but each may be slightly different taking into account the thickness of the paper and the wrapping structure.

[0029] The connecting portion 40 connects the front and rear edges 121SLF, 121SLB, 121SRF, 121SRB of each of the left and right outer wall equivalent portions 121 (i.e., the left outer wall equivalent portion 121L and the right outer wall equivalent portion 121R) to the front and rear edges 131SLF, 131SLB, 131SRF, 131SRB of each of the front and rear outer wall equivalent portions 131 (i.e., the front outer wall equivalent portion 131F and the rear outer wall equivalent portion 131B), using these edges as fold lines.

[0030] Furthermore, the connecting portion 40 is provided with fold lines at division lines 41LF, 41LB, 41RF, and 41RB that divide the connecting portion 40 at an angle of 45° (θ in FIG. 2) starting from corners 12CLF, 12CLB, 12CRF, and 12CRB of edges 11L, 11R, 11F, and 11B of the bottom plate equivalent portion 10. Note that notches 42LF, 42LB, 42RF, and 42RB are provided at the end of the connecting portion 40 opposite corner 12 of division line 41 to make it easier to fold along the fold of division line 41.

[0031] The extension portions 50 extend from both front and rear sides 123SLF, 123SLB, 123SRF, and 123SRB of the left and right inner wall corresponding portions 123 (i.e., the left outer wall corresponding portion 123L and the right outer wall corresponding portion 123R), using these sides as folding lines. The extension portions 50 respectively include inner wall facing portions 51LF, 51LB, 51RF, and 51RB connected to the left and right inner wall corresponding portions 123, side wall intervening portions 52LF, 52LB, 52RF, and 52RB connected to the inner wall facing portions 51, outer wall facing portions 53LF, 53LB, 53RF, and 53RB connected to the side wall intervening portion 52, and front and rear outer wall attached portions 54LF, 54LB, 54RF, and 54RB connected to the outer wall facing portion 53.

[0032] The side-wall interposed portion 52 is perpendicular to an extension of the dividing line 41 (dividing line 41LB) of the adjacent connecting portion 40 (connecting portion 40LB in the case of the side-wall interposed portion 52LB), and is sandwiched between two folding lines 52D1LF, 52D1LB, 52D1RF, and 52D1RB and two folding lines 52D2LF, 52D2LB, 52D2RF, and 52D2RB. Since the distance between folding lines 52D1 and 52D2 is the width of the side-wall interposed portion 52, it is preferable that the distance be approximately the same as or slightly narrower than the distance between the front and rear outer walls 31 and the front and rear inner walls 33, taking into account the actions and effects described below.

[0033] The attachment portion boundaries 53DLF, 53DLB, 53DRF, 53DRB, which are the boundaries between the outer wall facing portion 53 and the front and rear outer wall attachment portions 54, are fold lines and are on the same line as the fold line 123D (fold line 123DL in the case of attachment portion boundary 53DLB) between the adjacent left and right inner wall equivalent portions 123 and the left and right bottom plate attachment portion equivalent portions 124. Therefore, the front and rear outer wall attachment portions 54 extend on extension lines of the positions where the adjacent left and right bottom plate attachment portions 124 extend (left and right bottom plate attachment portions 124L in the case of front and rear outer wall attachment portions 54LB).

[0034] The left and right bottom plate attachment portions 124 have first overlap portions 125L, 125R extending in the front-rear direction. The front and rear outer wall attachment portions 54 have second overlap portions 55LF, 55LB, 55RF, 55RB extending in the front-rear direction. The first overlap portion 125 and the second overlap portion 55 are positioned on a straight line. The front and rear inner wall equivalent portions 133 have third overlap portions 135LF, 135LB, 135RF, 135RB in areas extending in the front-rear direction near both left and right edges (133SLF, 133SLB, 133SRF, 133SRB) of the front and rear inner wall equivalent portions 133F and 133B, respectively (i.e., the front inner wall equivalent portion 133F and the rear inner wall equivalent portion 133B).

[0035] The paper packaging box 1 according to this embodiment is formed by folding and pasting the unfolded body 101 as described above. At this time, preferably an automatic box-making device is used to convey the unfolded body 101 in a fixed direction while applying adhesive to predetermined locations on the unfolded body 101 and weaving in the predetermined locations to manufacture the paper packaging box 1. Of course, the unfolded body may also be manufactured manually without using an automatic box-making device. Below, the manufacturing process for the paper packaging box 1 will be explained, focusing on the case where an automatic box-making device is used. The unfolded body 101 is conveyed in the front-to-rear direction (for example, the direction of arrow X in Figures 2 and 3) by the automatic box-making device (not shown), and the following operations are performed during this conveyance.

[0036] First, the automatic box making device applies adhesive to the first glue tab 125 and the second glue tab 55 of the deployable body 101. When applying adhesive to the deployable body 101 by the automatic box making device, adhesive is appropriately discharged from a discharge port (not shown) directed toward the deployable body 101, so that one line of adhesive is applied from one discharge port to the deployable body 101 during transportation.

[0037] The first and second overlap portions 125L and 55L, and the first and second overlap portions 125R and 55R are positioned in a straight line in the front-to-rear direction, i.e., the conveying direction, so adhesive can be applied appropriately to the first and second overlap portions 125 and 55 by turning on and off the discharge from the two discharge ports. The application of adhesive to the third overlap portion (glue portion) 135 uses two discharge ports different from the two discharge ports used to apply adhesive to the first and second overlap portions 125 and 55. The third overlap portion (glue portion) 135 also extends in the front-to-rear direction, i.e., the conveying direction, so adhesive can be applied by turning on and off the discharge from the discharge ports. Therefore, adhesive can be easily applied using an automatic box-making device.

[0038] Next, the automatic box making device folds the side including the left and right inner wall equivalents 123 toward the front side along the fold line at the left and right boundary 121D between the left and right outer wall equivalents 121 and the left and right upper wall equivalents 122. In this invention and this embodiment, "folding toward the front side" means that the folds face toward the front side, which corresponds to a so-called "valley fold" when the unfolded body 101 shown in FIG. 2 is used as a reference. Therefore, "folding toward the back side" also corresponds to a "mountain fold." Furthermore, "folding back" means changing the orientation of the folds by 180 degrees so that the pieces of paper overlap. Furthermore, "folding up" means changing the orientation of the folds by 90 degrees so that they stand up approximately vertically from the original paper surface.

[0039] When folding the unfolded body 101 using an automatic box-making device, a pair of rollers (not shown) provided on the automatic box-making device is used to move the unfolded body 101 in the direction of arrow X, while folding each fold line (here, the left and right boundaries 121D) of the unfolded body 101 inward from both sides in the direction of arrow Y.

[0040] Fig. 3 is a plan view of the deployable body 101 shown in Fig. 2 folded back to the front side along the fold lines of the left and right boundaries 121DL, 121DR. In the deployable body 101 shown in Fig. 3, the surfaces of the left and right bottom plate attachment parts 124 abut against left and right regions of the surface of the bottom plate equivalent part 110, and the surfaces of the front and rear outer wall attachment parts 54 abut against left and right regions of the surface of the front and rear outer wall equivalent parts 131.

[0041] Because adhesive is applied to the first overlap portions 125 on the surfaces of the left and right bottom plate attachment portions 124 and the second overlap portions 55 on the surfaces of the front and rear outer wall attachment portions 54, the left and right bottom plate attachment portions 124 and the bottom plate equivalent portions 110, and the front and rear outer wall attachment portions 54 and the front and rear outer wall equivalent portions 131 are adhered at their contact portions. At this time, the automatic box making device functions to press the areas of the first overlap portions 125 of the left and right bottom plate attachment portions 124 and the areas of the second overlap portions 55 of the front and rear outer wall attachment portions 54 from above in the plan view shown in Figure 3, thereby firmly adhering them.

[0042] The left and right outer wall equivalent portions 121, the left and right upper wall equivalent portions 122 and the left and right inner wall equivalent portions 123, which are folded back at the left and right boundaries 121D, are folded toward the front side at the fold lines between the bottom plate equivalent portion 110 and the left and right outer wall equivalent portions 121 (edges 11L, 11R), between the left and right upper wall equivalent portions 122 and the left and right inner wall equivalent portions 123 (left and right boundary 122D), and between the left and right outer wall equivalent portions 121 and the connecting portion 40 (side 121S), and toward the back side at the fold lines between the left and right inner wall equivalent portions 123 and the left and right bottom plate attachment portion equivalent portions 124 (left and right boundary 123D), and between the outer wall opposing portion 53 and the front and rear outer wall attachment portion 54 (attachment portion boundary 53D). At this time, the fold lines (left and right boundaries 121D) between the left and right outer wall equivalent portions 121 and the left and right upper wall equivalent portions 122, which have already been folded back, are folded back in the opposite direction. These fold lines form folds at approximately right angles, and the left and right side walls 20 are erected from the bottom plate 10.

[0043] When viewed from the state of the unfolded body 101, the left and right side walls 20 are folded upright from the bottom plate 10 at fold lines between the bottom plate equivalent portion 110 and the left and right outer wall equivalent portions 121 (edges 11L, 11R), between the left and right outer wall equivalent portions 121 and the left and right upper wall equivalent portions 122 (left and right boundary 121D), and between the left and right upper wall equivalent portions 122 and the left and right inner wall equivalent portions 123 (left and right boundary 121D), respectively, toward the front side, and at fold lines between the left and right inner wall equivalent portions 123 and the left and right bottom plate attachment equivalent portions 124 (left and right boundary 123D), respectively. In this way, folds can be formed along the predetermined fold lines of the unfolded body 101.

[0044] Next, the automatic box making device applies adhesive to the third glue tab 135 of the unfolded body 101 after folding it back to the state shown in Figure 3. Note that depending on the automatic box making device, adhesive may also be applied to the third glue tab 135 when, or before or after, applying adhesive to the first glue tab 125 and the second glue tab 55. Furthermore, depending on the automatic box making device and configuration, the left and right side walls may be folded up without providing a step for setting the fold lines.

[0045] Furthermore, the automatic box making device folds the box toward the front side along the fold lines between the bottom plate equivalent portion 110 and the front and rear outer wall equivalent portion 131 (edges 11F, 11B), between the front and rear outer wall equivalent portion 131 and the front and rear upper wall equivalent portion 132 (front and rear boundary 131D), between the front and rear upper wall equivalent portion 132 and the front and rear inner wall equivalent portion 133 (front and rear boundary 132D), and between the front and rear outer wall equivalent portion 131 and the connecting portion 40 (side 131S), and toward the back side along the fold line between the front and rear inner wall equivalent portion 133 and the front and rear bottom plate opposing portion equivalent portion 134 (front and rear boundary 133D), and then folds it back toward the back side along the dividing line 41, so that the front and rear side walls 30 are erected from the bottom plate 10. At this time, the left and right side walls 20 are again in an upright state, and the connecting portions 40 and the extension portions 50 are folded between the front and rear outer walls 31 and the front and rear inner walls 33. The automatic box-making device pushes the unfolded body 101 into a formwork (not shown) and folds each fold line, thereby folding each side wall simultaneously. Note that, depending on the automatic box-making device and its configuration, the side walls may be folded sequentially. These processes will be described in detail using Figures 4 to 6.

[0046] 4 to 6, the left rear pair of connecting portion 40LB and extension portion 50LB will be described as a representative example of the four pairs of connecting portion 40 and extension portion 50 (left, right, front, and rear). When the left side wall corresponding portion (left outer wall corresponding portion 121L and left inner wall corresponding portion 123L) is folded up, the rear connecting portion 40LB and extension portion 50LB as well as the front connecting portion 40LF and extension portion 50LF are similarly folded and attached, symmetrically from front to back; however, the following description will only refer to the rear side. When the right side wall corresponding portion (right outer wall corresponding portion 121R and right inner wall corresponding portion 123R) is folded up, the right connecting portions 40RB, 40RF and extension portions 50RB, 50RF are similarly folded and attached, symmetrically, and therefore will not be described here.

[0047] 4 is a partially enlarged perspective view of the connecting portion 40LB, the extension portion 50LB, and their surroundings, showing a state in which the deployable body 101 shown in FIG. 3 is being folded up toward the front side along the fold line (edge 11B) between the bottom plate portion 110 and the rear outer wall portion 131B. At this time, as described above, the left and right side walls 20 are folded again between the bottom plate portion 110 and the left outer wall portion 121L (edge 11L), and the fold lines of the left boundary 121DL, the left boundary 121DL, and the left boundary 123DL, which have creases, are folded up together with edge 11L. In the following description using FIGS. 4 to 6, reference to the re-erecting of the left and right side walls 20 may be omitted.

[0048] When the rear outer wall portion 131B is folded from the deployed body 101 toward the front side (direction of arrow A) along the fold line of the edge 11B, the extension portion 50LB is folded toward the rear side along the fold line at the boundary (side 123SLB) between the left inner wall portion 123L and the inner wall facing portion 51LB and the fold line at the attachment portion boundary 53DLB, and is also folded toward the front side along parallel fold lines 52D1LB and 52D2LB on both sides of the side wall intervening portion 52. Simultaneously, the connecting portion 40LB is folded toward the front side along the fold line at the boundary 131SLB, 121SLB between the rear outer wall portion 131B and the left outer wall portion 121L and is also folded toward the rear side along the parting line 41LB. As the folding progresses, the connecting portion 40LB protrudes so as to be sandwiched between the inner wall facing portion 51LB and the outer wall facing portion 53LB.

[0049] Fig. 5 is a partially enlarged perspective view of the connecting portion 40LB and the extension portion 50LB and their surroundings, showing a state in which the deployed body 101 shown in Fig. 3 has been folded toward the front side along a fold line (edge 11B) between the bottom plate equivalent portion 110 and the rear outer wall equivalent portion 131B, after passing through the state shown in Fig. 4. As shown in Fig. 4, the extension portion 50LB is folded toward the front side along a fold line (side 123SLB) at the boundary between the left inner wall equivalent portion 123L and the inner wall facing portion 51LB and a fold line at the attachment portion boundary 53DLB, and is also folded toward the back side along parallel fold lines 52D1LB and 52D2LB on both sides of the side wall intervening portion 52.

[0050] 5, the cover 10 is folded toward the front surface (in the direction of arrow B) along the fold lines between the rear outer wall portion 131B and the rear upper wall portion 132B (rear boundary 131DB) and between the rear upper wall portion 132B and the rear inner wall portion 133B (rear boundary 132DB). At this time, the cover 10 is folded toward the back surface along the fold line between the rear inner wall portion 133B and the rear bottom plate facing portion 134B (rear boundary 133DB). These fold lines are folded until the cover 10 is folded upright, with the rear wall 30 standing upright from the bottom plate 10.

[0051] Fig. 6 is an enlarged cross-sectional view of cross section CC in Fig. 1, showing the rear side wall 30 and the left side wall 20 standing upright from the bottom plate 10. Fig. 6 shows the state of the unfolded body 101 in the middle of assembly, and since the shape is the same in the final state of the paper packaging box 1, the reference numerals of the unfolded body 101 shown in Fig. 2 and the reference numerals of the paper packaging box 1 in Fig. 1 are both shown, and hereinafter, either one will be used as appropriate in the description.

[0052] 6, in the deployable body 101, the outer wall facing portion 53LB and the rear outer wall equivalent portion 131LB face to face and abut against each other, and the inner wall facing portion 51LB and the rear inner wall equivalent portion 133LB face to face and abut against each other. Also, the rear bottom plate facing portion equivalent portion 134B and the bottom plate equivalent portion 110 face to face and abut against each other.

[0053] In this way, the extension portion 50LB is present between the rear outer wall equivalent portion 131LB and the rear inner wall equivalent portion 133LB, as shown in Figures 4 to 6. The outer wall facing portion 53LB faces the rear outer wall equivalent portion 131LB, with a portion of the outer wall facing portion 53LB being in contact with the rear outer wall equivalent portion 131LB, and the outer wall facing portion 53LB and the inner wall facing portion 51LB are spaced apart by the interposition of the side wall interposed portion 52LB.

[0054] 4 to 6, the connecting portion 40LB is folded back toward the front side at the fold lines at the boundaries 131SLB, 121SLB between the rear outer wall corresponding portion 131B and the left outer wall corresponding portion 121L, and is also folded back toward the back side at the division line 41LB. The connecting portion 40LB is surrounded by the inner wall facing portion 51LB, the side wall intervening portion 52LB, and the outer wall facing portion 53LB of the extending portion 50LB.

[0055] Then, the automatic box making device applies a press from the back surface side to the area of the third glue tab 135LB in the rear inner wall equivalent part 133B as shown by the arrow D in Fig. 6, and the rear inner wall equivalent part 133B is affixed to the inner wall facing part 51LB of the extension part 50LB, which is the adjacent extension part 50. At this time, the side wall inner intervening part 52LB functions as a spacer between the rear outer wall 31B and the rear inner wall 33B, so that the pressing by the automatic box making device can be supported from behind the rear inner wall 33B (the front surface side of the deployable body 101, the interior side of the rear wall 30B), and the adhesion of the third glue tab 135LB can be strengthened.

[0056] Figure 7 shows a partially enlarged perspective view of a typical paper packaging box with a framed double-wall structure, taken from the same position and angle as Figure 5, at the same stage as Figure 5, during the assembly process. This shows the state of assembling a paper packaging box from the developments shown in, for example, Patent Document 1 and Patent Document 2. In Figure 7, only the components necessary for explanation are labeled, but the box is the same as Figure 5 except for the differences explained below. Also, in Figure 7, the alphabets of the symbols indicating positions have been omitted.

[0057] 7, reference numeral 531 denotes a portion corresponding to the outer wall, reference numeral 533 denotes a portion corresponding to the inner wall, reference numeral 540 denotes a connecting portion, reference numeral 550 denotes an extending portion, reference numeral 551 denotes a portion facing the inner wall, and reference numeral 553 denotes a portion facing the outer wall. In the example shown in FIG. 7, as the assembly progresses, the extending portion 550 comes to be present between the portion corresponding to the outer wall 531 and the portion corresponding to the inner wall 533, and the connecting portion 540 comes to be present between the portion facing the inner wall 551 and the portion facing the outer wall 553 of the extending portion 550.

[0058] 7, however, the inner wall facing portion 551 and the outer wall facing portion 553 are directly connected, and there is no portion corresponding to a spacer such as the side wall interposed portion 52 in this embodiment, so even if an attempt is made to bond the inner wall corresponding portion 533 and the inner wall facing portion 551 together as in this embodiment, it is not possible to support the inner wall corresponding portion 533 from behind. In other words, the inner wall corresponding portion 551, to which the inner wall corresponding portion 533 is to be attached, is in a wobbly state in the front-to-rear direction, and the inner wall corresponding portion 533 and the inner wall facing portion 551 cannot be firmly bonded together.

[0059] The above problems in the example shown in Figure 7 become more apparent when attempting to attach the boxes using the press function of an automatic box-making machine, but manual assembly either does not result in a strong bond or requires time and effort to achieve a strong bond.

[0060] In contrast, according to this embodiment, the side wall interposition portion 52 functions as a spacer, so it can withstand pressure from an automatic box-making machine or manual pressing, and strong adhesion can be achieved with a simple operation. Therefore, even though it has a framed double-wall structure, the strong adhesion reinforces the strength of the box's corners. Furthermore, in the paper packaging box 1 according to this embodiment, the side wall interposition portion 52 maintains a constant distance between the front and rear outer walls 31 and the front and rear inner walls 33 within the front and rear side walls 30, so the structure itself contributes to reinforcing the strength of the box corners and enables the box as a whole to achieve high shape retention.

[0061] In addition, in this embodiment, the areas that become the glue tabs (left and right bottom plate attachment portions 24, front and rear outer wall attachment portions 54, and third glue tab 135) extend in one direction (the front-to-rear direction), which makes the box suitable for manufacturing using an automatic box making machine. However, the third glue tab 135 does not necessarily have to extend, and if it is in the form of a spot, for example, it still has excellent suitability for manufacturing using an automatic box making machine.

[0062] [Variations] Next, a modified example of the first embodiment will be described. Although the features of this modified example appear in the deployable body 101 shown in Figures 2 and 3, the first embodiment is described as an example that does not have these features. Therefore, this modified example will be described using Figures 2 and 3 as deployment views, as in the first embodiment. However, in this modified example, the deployable body will be denoted by the reference numeral 101'.

[0063] In this modified example, in the unfolded body 101′ shown in FIG. 2 , another fold line is provided in each of the extension sections 50 parallel to the fold line of the boundary 53D, and this fold line becomes the attachment section boundaries 56LB, 56LF, 56RB, and 56RF. Meanwhile, the line designated by the reference numeral 53D, which was the attachment section boundary in the first embodiment, becomes a fold line (crease) along with the left and right boundaries 123D, and is therefore referred to as an "auxiliary fold line" in this modified example. The areas between the attachment section boundary 56 and the auxiliary fold line 53D are referred to as wedge portions 57LF, 57LB, 57RF, and 57RB. The distance between the attachment section boundary 56 and the auxiliary fold line 53D (i.e., the width of the wedge portion 57) may be appropriately set while considering the action and effect described below.

[0064] In this modified example, a paper packaging box is manufactured using the same manufacturing process as in the first embodiment. However, a characteristic effect of this modified example is achieved when folding the paper packaging box toward the front side along the fold line (edge 11B) between the bottom plate equivalent portion 110 and the rear outer wall equivalent portion 131B, as explained in the first embodiment using Fig. 4. Hereinafter, as in the explanation using Fig. 4, the following explanation will be given by taking as a representative example the connecting portion 40LB and the extension portion 50LB, which are the rear left pair of the four connecting portions 40 and extension portions 50 (left, right, front, and rear).

[0065] In this modified example, when the rear outer wall portion 131B is folded toward the front surface along the fold line of the edge 11B, the fold line of the attachment portion boundary 56 and the auxiliary fold line 53LB are also folded toward the front surface. Figure 8 is a partially enlarged perspective view of the connecting portion 40LB and the extension portion 50LB and their surroundings, showing the state in which the deployable body 101' of this modified example is folded toward the front surface along the fold line (edge 11B) between the bottom plate portion 110 and the rear outer wall portion 131B. Note that at this time, the left and right side walls 20 are re-erected as described in the first embodiment, but in the following description using Figure 8, reference to the re-erecting of the left and right side walls 20 may be omitted.

[0066] In this modification, as in the first embodiment, outer wall facing portion 53LB and inner wall facing portion 51LB are spaced apart by side wall intervening portion 52LB. In this modification, by providing attachment portion boundary 56 as a folding line (farther from side wall intervening portion 52LB than the extension of left boundary 123DL), folding line 52D2LB is prevented from being pulled outward (toward left outer wall 21L), and the gap between side wall intervening portion 52LB can be formed with high precision.

[0067] Furthermore, in this modification, a wedge portion 57 formed by two fold lines, namely, attachment portion boundary 56 and auxiliary fold line 53D, extends approximately in the front-to-rear direction. Therefore, wedge portion 57 acts like a wedge that pushes connecting portion 40LB from the rear (direction of arrow E), thereby preventing side-wall interposed portion 52LB from being pushed toward rear outer wall 31B. Note that auxiliary fold line 53D does not necessarily have to be folded. For example, even if it has a curved surface, it can still have the effect of preventing fold line 52D2LB from being pulled outward and the effect of preventing side-wall interposed portion 52LB from being pushed toward rear outer wall 31B.

[0068] Above, the action and effect of positioning the attachment boundary 56 away from the side wall intervening portion 52 in the paper packaging box according to this modified example has been explained by taking as a representative the left rear pair of connecting portion 40LB and extension portion 50LB out of the four pairs of connecting portions 40 and extension portions 50 on the left, right, front and rear sides, but the same applies to the other three pairs of connecting portions 40LF, 40RF, 40RB and extension portions 50LF, 50RF, 50RB.

[0069] Therefore, according to this modification, in combination with the function of the side wall interposition portion 52 as a spacer, the box can firmly withstand pressing by an automatic box-making machine or manual pressing, and the adhesive can be made stronger with a simple operation. Therefore, even though it has a framed double-wall structure, the corners of the box are further reinforced by the strong adhesive. Furthermore, the paper packaging box according to this modification can form the corners with precision using the fold lines 56, and the side wall interposition portion 52 and the wedge portions 57 maintain a constant distance between the front and rear outer walls 31 and the front and rear inner walls 33 within the front and rear side walls 30. Therefore, the structure itself contributes to reinforcing the corners of the box, and the box as a whole can achieve better shape retention.

[0070] [Second embodiment] Fig. 9 is a perspective view of a paper packaging box 2 according to the second embodiment. As shown in Fig. 9, the paper packaging box 2 according to this embodiment comprises a rectangular bottom plate 60 having four edges (61L, 61R, 61F, and 61B in the unfolded body 201 in Fig. 10, which will be described later) on the left, right, front, and rear sides, and four side walls 70L, 70R, 80F, and 80B erected from the left, right, front, and rear edges (same as above) of the bottom plate 60, and is open at the top.

[0071] The paper packaging box 1 according to this embodiment is, in principle, symmetrical left-right and front-to-back, with the left and right side walls 70L, 70R being symmetrical left-right, and the front and rear side walls 80F, 80B being symmetrical front-to-back. However, unlike the first embodiment, in this embodiment, the longitudinal length of the front and rear side walls 80 is shorter than that of the left and right side walls 70, i.e., the upper opening is rectangular.

[0072] The left and right side walls 70 each have left and right outer walls 71 continuing to the bottom plate 10, left and right inner walls 73 facing the left and right outer walls 71, left and right upper walls 72 connecting the left and right outer walls 71 and the left and right inner walls 73 at the upper side, and left and right bottom plate attachment portions 74 continuing to the lower sides of the left and right inner walls 73. The left and right bottom plate attachment portions 74 face the inner surface of the bottom plate 60 and extend in a direction away from the left and right outer walls 71, and are attached to the inner surface of the bottom plate 60.

[0073] The front and rear side walls 80 each have a front and rear outer wall 81 that is continuous with the bottom plate 60, a front and rear inner wall 83 that faces the front and rear outer wall 81, a front and rear upper wall 82 that connects the front and rear outer wall 81 and the front and rear inner wall 83 at the upper side, and a front and rear bottom plate opposing portion 84 that is continuous with the lower side of the front and rear inner wall 83. The front and rear bottom plate opposing portion 84 faces the inner surface of the bottom plate 60 and extends in a direction away from the front and rear outer wall 81.

[0074] Fig. 10 is a plan view showing the unfolded body 201 of the paper packaging box 1 according to the first embodiment. The plan view shown in Fig. 10 is generally called a developed view. The paper packaging box 2 according to this embodiment is formed by folding and pasting a single sheet-like unfolded body 201 having a front and back surface, so that the front surface of the unfolded body 201 becomes the inner surface of the bottom plate 10. Note that in this embodiment, as in the first embodiment, the front and back surfaces of the unfolded body 201 are expressions used to distinguish between the paper surfaces, and are unrelated to the so-called front and back surfaces of the paper itself.

[0075] The unfolded body 201 of the paper packaging box 2 according to this embodiment includes a bottom plate equivalent portion 160 corresponding to the bottom plate 60, left and right outer wall equivalent portions 171 corresponding to the left and right outer walls 71, left and right upper wall equivalent portions 172 corresponding to the left and right upper walls 72, left and right inner wall equivalent portions 173 corresponding to the left and right inner walls 73, left and right bottom plate attachment equivalent portions 174 corresponding to the left and right bottom plate attachment portions 74, front and rear outer wall equivalent portions 181 corresponding to the front and rear outer walls 81, front and rear upper wall equivalent portions 182 corresponding to the front and rear upper walls 82, front and rear inner wall equivalent portions 183 corresponding to the front and rear inner walls 83, and front and rear bottom plate opposing equivalent portions 184 corresponding to the front and rear bottom plate opposing portions 84.

[0076] In this embodiment, the components designated by the reference numbers in the 60s, 70s, 80s, 160s, 170s, and 180s have basically the same configurations and functions as the components designated by the reference numbers in the 10s, 20s, 30s, 110s, 120s, and 130s, which are obtained by subtracting 5 from the tens digit. Explanations of the fact that the front-to-rear lengths of the components associated with the left and right side walls 70 designated by the reference numbers in the 70s and 170s are shorter than the left-to-right lengths of the components associated with the front and rear side walls 80 designated by the reference numbers in the 80s and 180s, as well as other differences based on the relationship of these lengths, will be omitted, and only the differences characteristic of this embodiment will be described below.

[0077] The unfolded body 201 of the paper packaging box 2 according to this embodiment also includes a connecting portion 40' and an extension portion 50, as in the first embodiment. The extension portion 50 in this embodiment has basically the same configuration as that in the first embodiment, and therefore the same reference numerals are used to designate components having the same configuration and function as the extension portion 50 and its constituent members in the first embodiment, and a detailed description thereof will be omitted. Furthermore, the connecting portion 40' in this embodiment has the same configuration as the connecting portion 40 in the first embodiment, with some exceptions, and therefore the same reference numerals are used to designate components having the same configuration and function as the connecting portion 40 and its constituent members in the first embodiment, and a detailed description thereof will be omitted.

[0078] In the developed body 201 of the paper packaging box 2 according to this embodiment, the widths of the left and right outer wall equivalents 171 (reference symbol e in FIG. 10) and the front and rear outer wall equivalents 181 (reference symbol g in FIG. 10) are substantially the same, as in the first embodiment. Also, the widths of the left and right inner wall equivalents 173 (reference symbol f in FIG. 10) and the front and rear inner wall equivalents 183 (reference symbol h in FIG. 10) are substantially the same, as in the first embodiment. However, the widths (e) of the left and right outer wall equivalents 171 and (f) of the left and right inner wall equivalents 173 are clearly shorter (e>f) even when taking into account the thickness of the paper and other factors, and the widths (g) of the front and rear outer wall equivalents 181 and (h) of the front and rear inner wall equivalents 183 are clearly shorter (g>h) even when taking into account the thickness of the paper and other factors.

[0079] In this embodiment, compared to the width (e) of the left and right outer wall equivalent portions 171 and the width (g) of the front and rear outer wall equivalent portions 181, the width (f) of the left and right inner wall equivalent portions 173 and the width (h) of the front and rear inner wall equivalent portions 183 are clearly shorter (e>f, g>h) even taking into account the thickness of the paper and other factors. Therefore, during the manufacturing process of the packaging paper box 2, when the sides including the left and right inner wall equivalent portions 173 and the front and rear inner wall equivalent portions 183 are folded back toward the front at fold lines 61L, 61R and fold lines 61F, 61B, the abutment positions of the surfaces of the left and right bottom plate attachment portion equivalent portions 174 and the front and rear bottom plate attachment portion equivalent portions 184 on the surface of the bottom plate equivalent portion 160 become closer to the edge (fold line) 61.

[0080] Fig. 11 is a partially enlarged cross-sectional view of the paper box 2 according to this embodiment, taken along the FF cross section in Fig. 9. As shown in Fig. 11, the width (f) of the left inner wall 73L is clearly short, so the contact position of the left bottom plate attachment portion 74 with the bottom plate 60 is closer to the edge 61, and the position of the left boundary 121DL is pulled downward (closer to the bottom plate 60). Therefore, as shown in Fig. 9, in the paper box 2 according to this embodiment, the left upper wall 72L is inclined so that the storage section side (the center side of the paper box 2) is lower. In other words, the left inner wall 73L is lower than the left outer wall 71L. This also applies to the width of the right inner wall 73R, the position of the right boundary 121DR, the inclination of the right upper wall 72R, and the height relationship between the right inner wall 73R and the right outer wall 71R (including symmetrical shapes).

[0081] 9, in the paper box 2 according to this embodiment, the left inner wall 73L is inclined so as to approach the left outer wall 71 as it approaches the bottom plate 60. Therefore, as shown in FIG. 10, the left side 183SLB of the rear inner wall equivalent part 183B is inclined so as to protrude towards the rear bottom plate opposing part equivalent part 184 so as to fit within the inclination of the left inner wall 73L.

[0082] 11 has been used to explain the shapes of the left and right side walls 70 of the paper packaging box 2 according to this embodiment, taking the left side wall 70L as an example, but the front wall 80F and the rear wall 80B also have similar shapes (including symmetrical shapes). That is, the relationship between the width of the front and rear inner wall 83FB, the position of the front and rear boundary 131DFB, the slope of the front and rear upper wall 82FB, and the height of the front and rear inner wall 83FB and the front and rear outer wall 81FB is similar (including symmetrical) to the relationship between the width of the left and right inner wall 73LR, the position of the left and right boundary 121DLR, the slope of the left and right upper wall 72LR, and the height of the left and right inner wall 73LR and the left and right outer wall 71LR.

[0083] In the unfolded body 201 of the paper packaging box 2 according to this embodiment, the connecting portion 40' is provided with protruding pieces 43LB, 43LF, 43RB, 43RF that protrude from sides 44LB, 44LF, 44RB, 44RF that face the boundaries (sides 171SLB, 171SLF, 171SRB, 171SRF) with the left and right inner wall equivalents 171. The boundaries (side 171S) between these protruding pieces 43 and the left and right inner wall equivalents 171 form fold lines. The protruding length of the protruding pieces 43 is approximately the same as the width of the front and rear upper walls 82FB (i.e., the length in the front-to-rear direction of the front and rear upper wall equivalents 182FB).

[0084] In the unfolded body 201 of the paper box 2 according to this embodiment, the third adhesive tab 185 does not remain within the area of the front and rear inner wall equivalents 183FB, but extends to the area of the front and rear upper wall equivalents 182FB. The third adhesive tab 185 in this embodiment is merely an extension of the area of the third adhesive tab 135 in the first embodiment, and still extends in the front-to-rear direction, so adhesive can be easily applied by an automatic box making device.

[0085] The unfolded body 201 is also folded appropriately in the same manner as in the first embodiment, and pasted appropriately to form the paper packaging box 2 according to this embodiment shown in Fig. 9. However, the process of folding the paper packaging box 2 according to this embodiment at the fold line (edge 61B) between the bottom plate portion 160 and the rear outer wall portion 181B differs from that of the first embodiment described using Fig. 4 due to the presence of the protruding piece 43, which is one of the characteristic features of this embodiment. As in the description using Fig. 4, the following description will be given using Fig. 12, taking as a representative example the rear left pair of connecting portion 40'LB and extension portion 50LB out of the four pairs of connecting portion 40' and extension portion 50 (left, right, front, and rear).

[0086] 12 is a partially enlarged perspective view of the connecting portion 40'LB, the extension portion 50LB, and their surroundings, showing the state in which they are being folded up from the deployable body 201 shown in FIG. 10 to the front side along the fold line (edge 61B) between the bottom plate equivalent portion 160 and the rear outer wall equivalent portion 181B. This is a perspective view taken at the same timing and from the same angle as FIG. 4 in the first embodiment. For ease of understanding, the protruding piece 43LB is shown folded at side 171SLB, but it is not yet folded at this timing.

[0087] 12, the bottom plate 60 is folded toward the front surface (in the direction of arrow G) along the fold lines between the rear outer wall equivalent 181B and the rear upper wall equivalent 182B (rear boundary 181DB) and between the rear upper wall equivalent 182B and the rear inner wall equivalent 183B (rear boundary 182DB). Then, each fold line, including the fold line of the side 44LB, is folded up until the rear wall 80B stands upright from the bottom plate 60. At this time, the protruding piece 43LB is folded toward the rear surface along the fold line of the side 44LB while being rolled up into the rear upper wall equivalent 182B, as shown in FIG. 12, and the upper surface of the protruding piece 43LB (the front surface side of the deployable body 201) comes into contact with the lower surface of the rear upper wall 82B (the front surface side of the deployable body 201, the inner side of the rear wall 80B). In FIG. 11, the protruding piece 43LB is shown by an imaginary line (dotted line) because it is hidden behind the rear upper wall 82B.

[0088] The third adhesive margin 185LB, which extends to the area of the rear upper wall equivalent 182B, is positioned on the lower surface of the rear upper wall 82B when the rear upper wall equivalent 182B becomes the rear upper wall 82B. Therefore, a part of the protruding piece 43LB that abuts on the lower surface of the rear upper wall 82B is affixed.

[0089] In this embodiment, as in the first embodiment, the outer wall facing portion 53LB and the inner wall facing portion 51LB are spaced apart by the side wall interposition portion 52LB. In this embodiment, the protruding piece 43LB overlaps the rear upper wall 82B to form a double layer, thereby reinforcing the area. Because the protruding length of the protruding piece 43LB is approximately the same as the width of the rear upper wall 82B (i.e., the length of the rear upper wall equivalent portion 182B in the front-to-rear direction), the protruding piece 43LB also functions to maintain a constant distance between the rear outer wall 31B and the rear inner wall 33B. Furthermore, because the protruding piece 43LB is attached to the rear upper wall 82L, the corners of the box are reinforced to a high degree, thereby achieving higher shape retention for the box as a whole.

[0090] The above has explained the action and effect of the protruding piece 43 in the paper packaging box 2 according to this embodiment by taking as a representative the left-rear pair of connecting portion 40'LB and extension portion 50LB out of the four pairs of connecting portion 40' and extension portion 50 on the left, right, front and rear sides, but the same applies to the other three pairs of connecting portions 40'LF, 40'RB, 40'RF and extension portions 50LF, 50RB, 50RF.

[0091] In this embodiment, an example is given in which the protruding length of the protruding piece 43 is approximately the same as the width of the front and rear upper wall 82FB (i.e., the length in the front-rear direction of the front and rear upper wall equivalent portion 182), but even if the distance is shorter than this, a reinforcing effect can be expected by overlapping with the front and rear upper wall 82 to form a double layer. Of course, it is preferable that the protruding length of the protruding piece 43 is approximately the same as the width of the front and rear upper wall 82FB (i.e., the length in the front-rear direction of the front and rear upper wall equivalent portion 182) as in this embodiment, in that a higher reinforcing effect can be achieved.

[0092] Furthermore, in this embodiment, an example is given in which the protruding piece 43 is attached to the rear upper wall 82, but even if the protruding piece 43 is not attached to this portion, the reinforcing effect can be expected due to the presence of the protruding piece 43. Of course, it is preferable that the protruding piece 43 is attached to the rear upper wall 82 as in this embodiment, as a higher reinforcing effect can be achieved.

[0093] The above-described embodiment and modifications are merely representative examples of the present invention, and the present invention is not limited to these embodiments. For example, the configuration of the second embodiment may also be combined with the configuration of the modification of the first embodiment.

[0094] In addition, while the above-described embodiment and modified examples all have front and rear bottom plate opposing portions (reference numerals 34, 84), the present invention is not limited to this, and it is also possible to have a configuration in which the front and rear inner walls are cut at their edges and these edges abut the bottom plate without having front and rear bottom plate opposing portions. However, from the viewpoint of the strength and stability of the front and rear side walls, and in turn the box as a whole, it is preferable to have front and rear bottom plate opposing portions.

[0095] Furthermore, in the above-described embodiments and modifications, examples have been given in which the left-right position of the attachment portion boundary, which is the boundary between the front and rear outer wall attachment portions and the outer wall opposing portions, is on the same line as the fold line between the connecting left and right inner wall equivalent portions and the left and right bottom plate attachment equivalent portions (first embodiment and second embodiment), and examples (modification) in which it is located on the side farther from the side wall internal interposition portion than the fold line, but in the present invention, it is also acceptable for it to be located on the side closer to the side wall internal interposition portion than the fold line. Of course, it is preferable for the left-right position of the attachment portion boundary to be on the same line as the fold line, and from the viewpoint of accurately manufacturing a box with a simple design, it is preferable for it to be located on the side farther from the side wall internal interposition portion.

[0096] Furthermore, the first embodiment and its modified examples may have a component equivalent to the protruding piece 43 in the second embodiment, or may have the slanted frame (the left and right upper walls 72 and the front and rear upper walls 82 are slanted) in the second embodiment but not have a component equivalent to the protruding piece 43.

[0097] In addition, those skilled in the art may implement various modifications in accordance with conventionally known knowledge without departing from the gist of the present invention. As long as such modifications still provide the configuration of the paper packaging box of the present invention, they are of course included in the scope of the present invention. [Explanation of symbols]

[0098] 1, 2: Paper packaging box, 10, 60: Bottom plate, 11, 61: Edge (fold line), 20, 70: Left and right side walls, 21, 71: Left and right outer walls, 22, 72: Left and right upper walls, 23, 73: Left and right inner walls, 24, 74: Left and right bottom plate attachment parts, 30, 80: Front and rear side walls, 31, 81: Front and rear outer walls, 32, 82: Front and rear upper walls, 33, 83: Front and rear inner walls, 34, 84: Front and rear bottom plate opposing parts, 40: Connection part, 41: Partition line, 42: notch, 43: protruding piece, 44: side, 50: extension portion, 51: inner wall facing portion, 52: side wall interposed portion, 52D: fold line, 53: outer wall facing portion, 53D: [first and second embodiments] attachment portion boundary (fold line), [variation example] auxiliary fold line, 54: front and rear outer wall attachment portion, 55:: second glue tab portion, 56: attachment portion boundary, 57: wedge portion, 101, 201: deployed body, 110, 160: equivalent to bottom plate part, 121, 171: parts corresponding to outer walls on the left and right sides, 121D, 122D, 123D, 171D, 172D, 173D: left and right boundaries (fold lines), 122, 172: parts corresponding to upper walls on the left and right sides, 123, 173: parts corresponding to inner walls on the left and right sides, 123S, 173S: sides, 124, 174: parts corresponding to bottom plate attachment parts on the left and right sides, 125, 175: first adhesive margin, 131, 181: parts corresponding to outer walls on the front and rear sides, 131D, 132D , 133D, 181D, 182D, 183D: front and rear boundaries, 131S, 181S: edges (fold lines), 132, 182: front and rear upper wall equivalent parts, 133, 183: front and rear inner wall equivalent parts, 134, 184: front and rear bottom plate opposing parts equivalent parts, 135, 185: third glue margin parts, 531: outer wall equivalent parts, 533: inner wall equivalent parts, 540: connecting parts, 550: extension parts, 551: inner wall opposing parts, 553: outer wall opposing parts

Claims

1. A paper packaging box comprising a rectangular bottom plate having four edges on the left, right, front and rear sides, and four side walls extending from the left, right and front and rear edges of the bottom plate, the box being open at the top, and formed by folding and attaching a sheet-like unfolded body having a single front and back surface so that the surface of the unfolded body becomes the inner surface of the bottom plate, The left and right side walls each have left and right outer walls connected to the bottom plate, left and right inner walls facing the left and right outer walls, left and right upper walls connecting the left and right outer walls and the left and right inner walls at their upper sides, and left and right bottom plate attachment portions connected to the lower sides of the left and right inner walls and facing the inner surface of the bottom plate, extending in a direction away from the left and right outer walls and attached to the inner surface of the bottom plate, the front and rear side walls each include a front and rear outer wall connected to the bottom plate, a front and rear inner wall facing the front and rear outer wall, and a front and rear upper wall connecting the front and rear outer wall and the front and rear inner wall at an upper side, The deployment body is a bottom plate equivalent portion corresponding to the bottom plate; Left and right outer wall equivalent portions corresponding to the left and right outer walls and connected to the left and right edges of the bottom plate equivalent portion as fold lines; Left and right upper wall equivalent portions corresponding to the left and right upper walls and connected to the left and right of the left and right outer wall equivalent portions with boundaries as fold lines; Left and right inner wall equivalent portions corresponding to the left and right inner walls and connected to the left and right of the left and right upper wall equivalent portions with boundaries as fold lines; Left and right bottom plate attaching portions corresponding to the left and right bottom plate attaching portions, which are connected to the left and right of the left and right inner wall corresponding portions with the boundaries as fold lines and extend in the front-to-rear direction; A front and rear outer wall equivalent portion corresponding to the front and rear outer walls and connected to the front and rear edges of the bottom plate equivalent portion as fold lines; A front and rear upper wall equivalent portion corresponding to the front and rear upper wall and connected to the front and rear of the front and rear outer wall equivalent portion with the boundary as a fold line; Front and rear inner wall equivalent portions corresponding to the front and rear inner walls and connected to the front and rear of the front and rear upper wall equivalent portions with boundaries as fold lines; Four connecting portions on which fold lines are provided on dividing lines that connect the left and right front and rear sides of the left and right outer wall equivalent portions and the left and right front and rear sides of the front and rear outer wall equivalent portions as fold lines, and divide the bottom plate equivalent portion at an angle of 45° with the corner of the edge as a base point; Four extension portions extending from both the front and rear sides of the left and right inner wall corresponding portions, respectively, along folding lines; Equipped with In the deployed body, each of the extension portions comprises an inner wall opposing portion connected to the left and right inner wall equivalent portions, a side wall intervening portion connected to the inner wall opposing portion and perpendicular to the extension line of the dividing line of the adjacent connecting portion, and sandwiched between two fold lines spaced at a distance substantially the same as or slightly narrower than the distance between the front and rear outer walls and the front and rear inner walls, an outer wall opposing portion connected to the side wall intervening portion, and front and rear outer wall attaching portions connected to the outer wall opposing portion at a fold line that is on the same line as or parallel to the fold line between the adjacent left and right inner wall equivalent portions and the left and right bottom plate attaching portion equivalent portions, and extending on an extension line of the position where the adjacent left and right bottom plate attaching portions extend, the four side walls are erected from the bottom plate by folding toward the front side along fold lines between the bottom plate equivalent portion and the left and right outer wall equivalent portions, between the left and right outer wall equivalent portions and the left and right upper wall equivalent portions, between the left and right upper wall equivalent portions and the left and right inner wall equivalent portions, between the bottom plate equivalent portion and the front and rear outer wall equivalent portions, between the front and rear outer wall equivalent portions and the front and rear upper wall equivalent portions, and toward the back side along fold lines between the left and right inner wall equivalent portions and the left and right bottom plate attachment equivalent portions, the left and right bottom plate attachment portions and the front and rear outer wall attachment portions are attached to the positions of the bottom plate equivalent portions and the rear outer wall equivalent portions that come into contact when the deployed body is folded back to the front surface along the fold lines between the left and right outer wall equivalent portions and the left and right upper wall equivalent portions, The front and rear inner wall corresponding portions are attached to the inner wall opposing portions of the adjacent extension portions with regions in the vicinity of both the front and rear left and right sides thereof as glue tabs, The extension portions are folded toward the back side at the fold lines at the boundaries between the left and right inner wall corresponding portions and the inner wall opposing portions and the fold lines at the boundaries of the pasted portions, and are present between the front and rear outer walls and the front and rear inner walls in a state where they are folded toward the front side at parallel fold lines on both sides of the side wall intervening portion, the connecting portion is folded toward the front surface at the fold lines of the boundaries between the front and rear outer wall corresponding portions and the left and right outer wall corresponding portions, and is folded back toward the back surface at the dividing line, and is surrounded by the inner wall opposing portion, the side wall intervening portion, and the outer wall opposing portion in the extension portion, The paper packaging box, wherein the side wall intervening portions function as spacers between the front and rear outer walls and the front and rear inner walls.

2. 2. The paper packaging box according to claim 1, wherein the boundary of the attachment portion is located on the left-right side farther from the side wall interposition portion than the fold line between the left and right inner wall corresponding portions and the left and right bottom plate attachment corresponding portions.

3. In the deployable body, each of the connecting portions is provided with a protruding piece protruding from a side opposite to a boundary between the left and right outer wall equivalent portions, and the side opposite to the boundary between the left and right outer wall equivalent portions is a fold line, 2. The paper packaging box according to claim 1, wherein the protruding pieces are folded back along fold lines at boundaries with the left and right inner wall portions, and abut against the lower surfaces of the front and rear upper walls.

4. The paper packaging box according to claim 3, wherein at least a portion of the contact surface of each of the protruding pieces that contacts the lower surface of the front and rear upper walls is attached.

5. The paper packaging box according to claim 1 , wherein the left and right inner walls and the front and rear inner walls are lower than the left and right outer walls and the front and rear outer walls.

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