Blank, box, and blank assembly jig

Abstract

To provide a blank which can be very easily assembled, can stand by itself as a box body in a temporarily assembled state in which a first surface plate and a second surface plate are both folded, and has good storage efficiency, and to provide an assembly jig which can efficiently assemble the blank as the box body in the temporarily assembled state.SOLUTION: At least one locking structure configured to form a double-sided plate coupling structure when the first surface plate and the second surface plate are folded together with respect to the bottom plate, the locking structure comprises a flap part connected to an edge of the first surface plate via a flap fold line, and a hook-shaped slit part disposed in the second surface plate, and when the second surface plate is folded with respect to the bottom plate, the slit part opens to form the gap part and the second surface plate pressing part, when the flap part is folded back and the first surface plate is folded back, the tip of the flap part is inserted into the slit part and the gap part, and pressed by the second surface plate pressing part to form a connection structure.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a blank for a box body and an assembly jig for the blank, and more particularly to a blank for forming a box body (packaging box) and an assembly jig for assembling the blank into a self-standing state as a pre-assembled box body. [Background technology]

[0002] BACKGROUND ART Various blanks have been proposed for assembling packaging containers such as packaging boxes made of sheet-like materials such as corrugated cardboard and paperboard. Among them, for example, Patent Document 1, filed by the present applicant, discloses a blank having a rectangular bottom panel, first and second panels foldably connected to two adjacent sides of the bottom panel, a first flap foldably connected to an edge of the first panel and having an engaging portion, and a second flap foldably connected to an edge of the second panel and having a space into which the first flap is inserted and an engaged portion with which the engaging portion engages, and a locking structure configured so that when the double-sided panels are folded together, the connecting structure of the double-sided panels is simultaneously formed at all points on the vertices of the bottom panel. Patent Document 1 also discloses that this blank does not require skill in assembly and can be easily and quickly assembled even by a person unfamiliar with assembly work, and that the blank can stand on its own as a box in a pre-assembled state, allowing storage of items in this state, thereby improving work efficiency.

[0003] Patent Document 1 also discloses an assembly jig that includes a jig main body into which the blank is loaded and a pressing tool that presses the bottom plate of the blank from above into the jig main body, the jig main body including a first flap guide plate that folds the first flap, a second flap guide plate that folds the second flap, a first panel guide that folds the first panel, and a second panel guide that has a gentler inclination angle than the first panel guide surface and folds the second panel prior to the first panel, and is equipped with a connecting structure forming mechanism that simultaneously forms connecting structures between the first panel and the second panel at all points on the vertices of the bottom panel. Patent Document 1 discloses that this assembly jig can make the blank self-standing as a box in a pre-assembled state by the simple operation of pressing the bottom plate of the blank loaded into the jig main body from above with the pressing tool, thereby enabling the blank to be assembled efficiently. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2020-093846 Summary of the Invention [Problem to be solved by the invention]

[0005] Incidentally, the technology disclosed in Patent Document 1 certainly eliminates the skill and labor required when assembling conventional blanks on-site, and also reduces the time required for assembly, allowing even those without particular skill to assemble the blanks quickly with simple work, thereby improving the ease of assembling the blanks. Furthermore, the blank disclosed in Patent Document 1 can stand on its own as a box in a pre-assembled state in which both the first and second panels are folded. Therefore, the pre-assembled box can be stably placed on a flat surface, and multiple boxes can also be stacked for storage. That is, the blank disclosed in Patent Document 1 has both the feature of being extremely easy to assemble and the feature of being able to stand on its own as a box in a partially assembled state.

[0006] However, in the blank disclosed in Patent Document 1, the flaps that make up the locking structure are provided on each of the first and second panels that sandwich the apex of the bottom panel, and in the box in a pre-assembled state, the connecting structure formed by the engagement of the two flaps is provided on the inside of the first and second panels. As a result, the flaps that make up the connecting structure protrude inward by the amount of their thickness, narrowing the opening of the box in a pre-assembled state. As a result, when the boxes in a pre-assembled state are stacked for storage, the apex of the bottom panel of the upper box in a pre-assembled state hits the inner flaps that make up the connecting structure of the lower box in a pre-assembled state, causing the upper box in a pre-assembled state to be placed at an angle or the bottom panels of the upper and lower boxes in a pre-assembled state to be placed apart, resulting in low storability and storage efficiency and leaving room for improvement.

[0007] Therefore, there was a need for a blank that could be assembled extremely easily, could stand on its own as a box in a pre-assembled state, and had improved storage properties and storage efficiency when assembled as a box in a pre-assembled state. Furthermore, since the assembly jig disclosed in Patent Document 1 is dedicated to the blank disclosed in Patent Document 1, there was a demand for an assembly jig dedicated to blanks that not only has the above-mentioned ease of assembly and self-standing ability, but also has improved storage ability and storage efficiency.

[0008] The present invention aims to solve the problems of the prior art described above, and to provide a blank that can be assembled extremely easily, that can stand on its own as a box in a pre-assembled state in which both the first panel and the second panel are folded, and that has good storage efficiency, and an assembly jig that can efficiently assemble this blank into a box in a pre-assembled state. [Means for solving the problem]

[0009] In order to achieve the above object, a blank according to a first aspect of the present invention is a blank for forming a box, which has a polygonal bottom panel, a first panel connected to one of two adjacent sides of the bottom panel with a vertex therebetween in a bendable manner, and a second panel connected to the other side in a bendable manner, and which has at least one locking structure configured so that when the first panel and the second panel are both folded, a connecting structure between the first panel and the second panel is formed at the vertex of the bottom panel, The box has a first top panel fold line that is spaced a predetermined distance outward from and parallel to a first fold line that is provided between the bottom panel and the first panel, a first side panel portion that is provided between the first fold line and the first top panel fold line and forms a side panel of the box, and a first top panel portion that is continuous with the first side panel portion and is provided outward from the first top panel fold line and forms a part of the top panel of the box, and the second panel is a second top panel that is spaced a predetermined distance outward from and parallel to a second fold line that is provided between the bottom panel and the second panel. a fold line, a second side panel portion that is provided between the second fold line and the second top panel fold line and forms a side panel of the box body, and a second top panel portion that is continuous with the second side panel portion and is provided outward from the second top panel fold line and forms a part of the top panel of the box body, and the locking structure portion is a flap portion that is provided on the edge of the first side panel portion and connected via a flap fold line that extends in a direction perpendicular to the first fold line, and a flap portion that is provided within the second panel on the edge side of the second panel, inside the edge of the second panel, and extends from the second side panel portion to the second fold line and a hook-shaped slit portion extending outward (further extending parallel to the second fold line), and when the second panel is folded along the second fold line relative to the bottom panel, the slit portion opens to form a gap and a second panel pressing portion, and when the flap portion is folded back at the flap fold line and the first panel is folded back, the tip of the flap portion is inserted into the slit portion and the gap and is pressed by the second panel pressing portion to form a connecting structure.

[0010] Here, it is preferable that the first panel is folded back toward the front surface, the second panel is pressed from the back surface side and bent at the second fold line relative to the bottom panel, the flap portion is folded back toward the front surface at the flap fold line, the tip of the flap portion is formed so as to be inserted into the slit portion and the void portion on the back surface side of the second panel, and the locking structure portion is configured so that the connecting structure between the first panel and the second panel is formed on the back surface side of the two panels at the apex of the bottom panel. Preferably, two locking structures are provided, and more preferably, four are provided. Preferably, the slit portion is disposed outward from a position spaced outward from the second fold line, and the second fold line extends from one edge to the other edge of the second panel.

[0011] Furthermore, the slit portion is positioned outward from a position on the second fold line, and in addition to the second fold line provided on the edge side of the second panel, there is a third fold line (provided parallel to the second fold line) between the bottom panel and the second panel inward from the position where the slit portion is provided, and the second panel is pressed from the back side and bent relative to the bottom panel at the second fold line and the third fold line, and it is preferable that the third fold line is formed in a position farther from the bottom panel than the second fold line. Preferably, the second panel further has a notch at the outer end of the slit. It is preferable that the tip of the flap portion is covered by the second panel when the first panel and the second panel are folded. It is preferable that the flap portion has a notch formed at the tip on the side farther from the edge of the second panel, and it is also preferable that the flap portion has a notch formed at the tip on the side closer to the edge of the second panel.

[0012] In order to achieve the above object, an assembly jig of a second aspect of the present invention is the blank assembly jig of the first aspect of the present invention, and comprises a jig body into which a blank is loaded, and a pressing tool that presses the bottom plate of the blank from the front side to force it into the jig body, and the jig body has a first panel guide mechanism that presses the first panel of the blank from the back side of the blank to fold it along the first fold line when the pressing tool presses the bottom plate of the blank from the front side to force it into the jig body, a second panel guide mechanism that presses the second panel of the blank from the back side to fold it along the second fold line, and a flap guide mechanism that presses the flap portion of the blank from the back side to fold it along the flap fold line, and the second panel guide mechanism is configured to form a gap portion that becomes a space between the second panel and the second panel guide mechanism when pressing the second panel, and The bottom panel of the blank placed on the jig is pressed from the front side with a pressing tool and forced into the jig body, so that first the second panel guide mechanism presses the second panel to bend it along the second fold line (forming a gap) and opens a slit to form a void and a second panel pressing section, and at the same time the flap guide mechanism presses the flap section to bend it relative to the first panel along the flap fold line, and then the first panel guide mechanism presses the first panel to bend it along the first fold line, causing the flap section bent at the flap fold line (edge ​​of the first panel) to rotate along the second panel, and the tip of the flap section is inserted into the slit and void through the gap, and then pressed from the back side by the second panel pressing section to form a connecting structure between the first panel and the second panel at the apex of the bottom panel.

[0013] Here, it is preferable that the pressing tool has a protrusion on its side surface for forming a larger gap. [Effects of the Invention]

[0014] According to the first aspect of the present invention, a blank can be provided that is extremely easy to assemble, can stand on its own as a box body in a provisionally assembled state in which both the first panel and the second panel are folded, and can be easily stacked when storing the provisionally assembled box body, resulting in excellent storability (stackability). Furthermore, according to the second aspect of the present invention, it is possible to provide an assembly jig that can efficiently assemble such blanks into a box body in a pre-assembled state. [Brief explanation of the drawings]

[0015] [Figure 1] FIG. 1 is a plan view showing an example of a blank according to an embodiment of the present invention. [Figure 2] FIG. 2 is an enlarged view of a lock structure portion of the blank shown in FIG. [Figure 3] 3 is a schematic diagram showing an example of an open state of an open slit portion of the lock structure portion shown in FIG. 2 and a state of a flap portion before insertion. FIG. [Figure 4] 3 is a schematic diagram showing an example of a state in which a flap portion of a lock structure portion of the blank shown in FIG. 2 is inserted into a slit portion to form a connecting structure. FIG. [Figure 5] 3 is a schematic diagram showing another example of a state in which a flap portion of a lock structure portion of the blank shown in FIG. 2 is inserted into a slit portion to form a connecting structure. FIG. [Figure 6] FIG. 2 is a schematic perspective view showing a provisionally assembled state of the blank shown in FIG. 1. [Figure 7] 3A and 3B are schematic diagrams showing the opening state of the slit portion of the lock structure portion shown in FIG. 2 when the second panel of the blank shown in FIG. 1 is raised, where (a) is a schematic diagram when the second panel is raised only slightly, and (b) is a schematic diagram when the second panel is raised more. [Figure 8] 4(a) and 4(b) are plan views showing other examples of the flap portion of the blank of the present invention. [Figure 9] FIG. 10 is a plan view showing another example of a blank according to an embodiment of the present invention. [Figure 10] FIG. 11 is an enlarged view of the locking structure of the blank shown in FIG. 10. [Figure 11] 11 is a schematic diagram showing an example of a state in which a flap portion of a lock structure portion of the blank shown in FIG. 10 is inserted into a slit portion to form a connecting structure, as viewed from the inside. FIG. [Figure 12] 13 is a schematic diagram showing the formed state of the connecting structure of the lock structure portion of the blank shown in FIG. 12, as viewed from the outside. FIG. [Figure 13] 10 is an enlarged plan view showing a modified example of a lock structure portion applied to the blank shown in FIG. 9. FIG. [Figure 14] 10 is an enlarged plan view showing another modified example of the lock structure portion applied to the blank shown in FIG. 9. FIG. [Figure 15] 10 is an enlarged plan view showing another modified example of the lock structure portion applied to the blank shown in FIG. 9. FIG. [Figure 16] 10 is an enlarged plan view showing another modified example of the lock structure portion applied to the blank shown in FIG. 9. FIG. [Figure 17] 10 is an enlarged plan view showing another modified example of the lock structure portion applied to the blank shown in FIG. 9. FIG. [Figure 18] 10 is an enlarged plan view showing another modified example of the lock structure portion applied to the blank shown in FIG. 9. FIG. [Figure 19] 10 is an enlarged plan view showing another modified example of the lock structure portion applied to the blank shown in FIG. 9. FIG. [Figure 20] FIG. 2 is a plan view showing an example of a configuration of a jig body of an assembly jig according to an embodiment of the present invention. [Figure 21] 21 is a plan view showing an example of a configuration of a pressing tool used to configure an assembly jig in combination with the jig main body shown in FIG. 20. FIG. [Figure 22] FIG. 21 is a front view of the jig body shown in FIG. 20. [Figure 23] FIG. 21 is a side view of the jig body shown in FIG. 20. [Figure 24] FIG. 22 is a front view of the pressing tool shown in FIG. 21. [Figure 25] FIG. 22 is a side view of the pressing tool shown in FIG. 21. [Figure 26] 21 is a plan view showing a state in which the blank shown in FIG. 1 is set (loaded) in the jig body shown in FIG. 20. FIG. [Figure 27] 21 is a schematic diagram showing the state of the flap portion before insertion into the slit portion of the lock structure portion of the blank shown in FIG. 1 in contact with the second panel guide mechanism of the jig body shown in FIG. 20. DETAILED DESCRIPTION OF THE INVENTION

[0016] The blank and the blank assembly jig according to the present invention will be described in detail below. The following description of the components will be given based on a representative embodiment of the present invention, but the present invention is not limited to such an embodiment. The blank of the first embodiment of the present invention is a blank for forming a box (packaging box), and has a polygonal bottom panel, a first panel foldably connected to one of two adjacent sides sandwiching the vertex of the bottom panel, and a second panel foldably connected to the other side, and has at least one locking structure portion configured so that when the first panel and the second panel are both folded, a connecting structure between the first panel and the second panel is formed at the vertex of the bottom panel.

[0017] Here, the first panel has a first top panel fold curve that is arranged parallel to and spaced a predetermined distance outward from the first fold curve that is arranged between the bottom panel and the first panel, a first side panel portion that is arranged between the first fold curve and the first top panel fold curve and forms a side panel of the box body, and a first top panel portion that is arranged contiguous with the first side panel portion and outward from the first top panel fold curve and forms part of the top panel of the box body. The second panel also has a second top panel fold curve that is arranged parallel to and spaced a predetermined distance outward from the second fold curve that is arranged between the bottom panel and the second panel, a second side panel portion that is arranged between the second fold curve and the second top panel fold curve and forms a side panel of the box body, and a second top panel portion that is arranged contiguous with the second side panel portion and outward from the second top panel fold curve and forms part of the top panel of the box body.

[0018] The locking structure is composed of a flap portion provided on the edge of the first side panel portion and connected via a flap fold line extending perpendicular to the first fold line, and a hook-shaped slit portion provided within the second panel, on the edge side of the second panel, inside the edge of the second panel, and extending from the second side panel portion outward relative to the second fold line. When the second panel is folded along the second fold line relative to the bottom panel, the slit portion opens to form a gap portion and a second panel pressing portion, and when the flap portion is folded back at the flap fold line and the first panel is folded back, the tip of the flap portion is inserted into the slit portion and the gap portion and pressed by the second panel pressing portion to form a connecting structure.

[0019] The blank of the present invention may have any other specific configuration as long as it has the above-mentioned configuration. The material constituting the blank of the present invention can be selected from various paper materials such as cardboard and thick paper, but the paper quality can be any, and it can also be coated with various types of material or made from resins other than paper. Furthermore, the type of box formed from the blank of the present invention may be any type, as long as it can be assembled so that an engagement structure is formed between two adjacent face plates that stand upright on a bottom face plate, and may be, for example, a Yakko type (tataou type), a C type, an N type, etc. Furthermore, the structure of the lid that forms the top surface of the box is not particularly limited, and may be one that employs a structure such as an A type or a B type. In the following, a blank according to a first embodiment of the present invention will be described taking as an example a blank made of a corrugated cardboard sheet capable of forming a folding-type packaging box having a rectangular bottom panel.

[0020] The blank assembly jig of the second embodiment of the present invention is the blank assembly jig of the first embodiment of the present invention, and comprises a jig body into which the blank is loaded and a pressing tool that presses the bottom panel of the blank from the front side and pushes it into the jig body. Here, the jig body has a first panel guide mechanism that presses the first panel of the blank from the back side of the blank to bend it along the first fold line when the pressing tool presses the bottom panel of the blank from the front side and pushes it into the jig body, a second panel guide mechanism that presses the second panel of the blank from the back side to bend it along the second fold line, and a flap guide mechanism that presses the flap portion of the blank from the back side to bend it along the flap fold line. Furthermore, the second panel guide mechanism is configured to form a gap portion that serves as a space between the second panel and the second panel guide mechanism when the second panel is pressed.

[0021] Then, the bottom panel of the blank placed on the jig body is pressed from the front side with a pressing tool and pushed into the jig body, whereby first the second panel guide mechanism presses the second panel to bend it along the second fold line, preferably forming a gap portion and opening a slit portion to form a void portion and a second panel pressing portion, and then the flap guide mechanism presses the flap portion to bend it against the first panel along the flap fold line. Next, the bottom panel is further pressed with the pressing tool to push it further into the jig body, and the first panel guide mechanism presses the first panel to bend it along the first fold line, causing the flap portion bent at the flap fold line (edge ​​of the first panel) to rotate along the second panel, inserting the tip of the flap portion into the slit portion and void portion through the gap portion, and pressing with the second panel pressing portion from the back side, forming a connecting structure between the first panel and the second panel at the vertex of the bottom panel.

[0022] Using an assembly jig configured as described above, simply by pressing a blank bottom panel into the jig body with a pressing tool, one of the second panel panels adjacent to one vertex of the bottom panel and the flap section of the locking structure section are bent and raised, and the slit section of the locking structure section is opened to form a gap and a second panel pressing section. Next, by bending and raising the other first panel panel at one vertex of the bottom panel, the folded flap section is rotated and inserted into the gap in the slit section, and the flap section inserted into the gap is pressed with the second panel pressing section, a solid connecting structure is formed by the flap section and the slit section, and it can be assembled extremely easily as a box in a pre-assembled state that is self-standing and has good storability.

[0023] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A blank and an assembly jig for the blank according to the present invention will be described in detail below with reference to preferred embodiments shown in the accompanying drawings. (blank) FIG. 1 is a plan view schematically showing a first example, which is an example of a blank according to a first embodiment of the present invention. The blank 10 of the present invention shown in FIG. 1 is configured to have a cross shape within a planar region. The blank 10 has a rectangular bottom panel 12, a pair of first panels 14 (14a, 14b) connected outward from each of a pair of opposing sides of the bottom panel 12, and a pair of second panels 16 connected outward from each of the other pair of opposing sides of the bottom panel 12. Here, the first panels 14a and 14b are simply referred to as the first panels 14 unless otherwise specified. In the present invention, the side toward the center is referred to as the inside, and the side away from the center is referred to as the outside. For example, in the blank 10, the side toward the bottom panel 12 is referred to as the inside or inner side, and the side away from the bottom panel 12 is referred to as the outside or outward side.

[0024] In the present invention, as shown in FIG. 1, it is preferable that the shape of the bottom panel 12 is rectangular, i.e., oblong. However, the present invention is not limited to this as long as it has a first panel and a second panel that are shaped to form a packaging box. For example, it may be a simple square, an octagon, or another polygon. The blank 10 further has four locking structure portions 22, each comprising four flap portions 18 connected to the edge of each of the first panel 14a and 14b on both sides, and four slit portions 20 provided in the second panel 16 corresponding to the four flap portions 18, respectively.

[0025] A total of two first fold lines 24 are formed between the first panel 14 and the bottom panel 12, i.e., on each of two sides of one of the bottom panels 12. The first panel 14 is connected to the sides of the bottom panel 12 via the first fold lines 24 so as to be foldable. Between the second panel 16 and the bottom panel 12, i.e., on the other two sides of the bottom panel 12, a total of four second fold lines 26 are formed on both end edge sides (outsides) of the second panel 16, and a total of two third fold lines 28 are formed on the center side of the second panel 16. Here, the second fold lines 26 are formed slightly closer to the bottom panel 12 than the third fold lines 28. The reason for this will be described later. Therefore, the other side of the bottom panel 12 is not in a straight line, but the second panel 16 is connected to the side of the bottom panel 12 via a second fold line 26 and a third fold line 28 so as to be foldable.

[0026] A flap fold line 30 is formed between the flap portion 18 and one edge of the first panel 14 that extends in a direction perpendicular to the first fold line 24 . The ends of the first fold lines 24 are the ends of one side of the bottom plate 12, and therefore form vertices 32 of the bottom plate 12. Therefore, the two end portions of the two first fold lines 24 form four vertices 32 of the bottom plate 12. The four flap portions 18 are adjacent to the four vertices 32 of the bottom panel 12, respectively.

[0027] Here, the first fold line 24, the second fold line 26, the third fold line 28, and the flap fold line 30 are arranged so that the angles they form with respect to the grain direction of the cardboard sheet (indicated by the striped pattern within the circle in FIG. 1) are, for example, 45°. The grain direction of the cardboard sheet is not particularly limited, and the first fold line 24, the second fold line 26, the third fold line 28, and the flap fold line 30 may be arranged so that they are perpendicular to the grain direction of the cardboard sheet. By arranging the first fold line 24, the second fold line 26, and the third fold line 28 so that the angles they form with respect to the grain direction of the cardboard sheet are 45°, the foldability can be improved. In addition, the first fold line 24 and the third fold line 28 may have linear folds or perforations formed except on both end sides of each, and by reducing rigidity, the first panel 14 and the second panel 16 can be easily folded relative to the bottom panel 12. In addition, the second fold line 26 and the flap fold line 30 are creased to reduce rigidity, making it easier for the second panel 16 and the flap portion 18 to bend relative to the bottom panel 12, respectively.

[0028] One of the first panels 14a has a rectangular (first) side panel 34 that forms a side panel of the packaging box, and a roughly rectangular outer (first) top panel 36a that forms part of the top panel of the packaging box. Here, the top panel has the same shape as the bottom panel 12. The side panel 34 and the outer top panel 36a are continuous via an outer (first) top panel fold line 38 that extends parallel to the first fold line 24. In the first panel 14a, the side panel 34 and the inner side of the outer top panel 36a (the side closer to the side panel 34) have the same width as the adjacent side of the bottom panel 12, but the outer side of the outer top panel 36a (the side farther from the side panel 34) is narrower than the side of the bottom panel 12, making it easier to assemble the packaging box. The shape of the first panel 14a may be any shape as long as it can be assembled into a packaging box. An insertion piece 40 protrudes from the center of the tip of the outer top plate 36a and can be bent freely along an insertion piece fold line 42. Recesses 40a are formed at the base of both sides of the insertion piece 40, with protruding pieces 40b on the outside of the recesses 40a. In addition, mountain-shaped opening perforations 44 are formed on the side plate 34 and the outer top plate 36a from both edges of the outer top plate 36a toward the side plate 34 so that the packaging box can be opened by cutting it after it has been formed into a packaging box.

[0029] The other first panel 14b has a rectangular side panel 34 that forms the side panel of the packaging box and an outer top panel 36b that forms part of the top panel. The side panel 34 and the outer top panel 36b are continuous via an outer top panel fold line 38 that extends parallel to the first fold line 24. The insides of the side panel 34 and the outer top panel 36b (the sides closer to the side panel 34) of the first panel 14b are the same width as the sides of the adjacent bottom panel 12, while the outsides of the outer top panel 36b (the sides farther from the side panel 34) are narrower than the sides of the bottom panel 12, facilitating assembly into a packaging box. The outermost long sides of the rectangular outer top panel 36b bulge outward in a mountain-like shape. The shape of the first panel 14b may be any shape as long as it can be assembled into a packaging box. A cutout 46 into which the insertion piece 40 of one of the first panel panels 14a is inserted is formed in the outer central portion of the outer top surface portion 36b. The cutout 46 has a width on the inside that allows the protruding pieces 40b on both sides of the insertion piece 40 to pass through, and the cutout on the outside is narrow enough that the recessed portions 40a on both sides can pass through but the protruding pieces 40b on both sides get caught and cannot pass through. In the following description, the outer top panel portions 36a and 36b will be simply referred to as the outer top panel portion 36 unless a distinction is particularly needed between them.

[0030] Each of the second panels 16 has the same configuration and includes a (second) side panel 48 that forms a side panel of the packaging box, and an inner (second) top panel 50 that forms part of the top panel of the packaging box. In the second panel 16, the insides (sides closer to the side panel 48) of the side panel 48 and the inner top panel 50 are narrower than the sides of the adjacent bottom panel 12, making it easier to assemble the packaging box. The outside of the inner top panel 50 (side farther from the side panel 48) becomes even narrower, and a circular notch is provided at the outer apex. The side plate portion 48 is composed of side plate end portions 48a provided on both outer sides and bent by the second fold line 26, and a side plate central portion 48b provided in the central portion between the slit portions 20 on both sides of the second panel 16 and bent by the third fold line 28. The side panel end portions 48a on both outer sides of the side panel portion 48 and the inner top panel portion 50 are continuous via an inner (second) top panel fold line 52a that extends parallel to the second fold line 26. The side panel central portion 48b on the inner side of the side panel portion 48 and the inner top panel portion 50 are continuous via an inner top panel fold line 52b that extends parallel to the third fold line 28 and is provided between the slit portions 20. As described above, the second fold line 26 is formed slightly closer to the bottom panel 12 than the third fold line 28, and therefore it is preferable that the inner top panel fold line 52a is also formed slightly closer to the bottom panel 12 than the inner top panel fold line 52b.

[0031] In addition, perforations are formed in the outer top panel fold line 38 and the inner top panel fold line 52b, which reduces rigidity and makes it easier to bend the outer top panel portions 36a and 36b relative to the side panel portion 34, and the inner top panel portion 50 relative to the side panel central portion 48b. In addition, the insertion piece fold line 42 and the inner top plate fold line 52a are each provided with creases to reduce rigidity, making it easier to bend the insertion piece 40 relative to the outer top plate portion 36a and the inner top plate portion 50 relative to the side plate end portion 48a.

[0032] The blank 10 shown in Figure 1 has a locking structure portion 22 at the vertex 32 of the bottom panel 12 that is configured to form a connecting structure between the first panel 14 and the second panel 16 when the first panel 14 and the second panel 16 that sandwich the vertex 32 of the bottom panel 12 are both folded so that they stand upright relative to the bottom panel 12. In the present invention, whether the bottom panel 12 is rectangular and has four vertices, as in the illustrated example, or another polygonal shape and has multiple vertices, the locking structure 22 only needs to be located at at least one vertex 32 of the bottom panel 12 so that the connecting structure between the first panel 14 and the second panel 16 is formed at at least one vertex 32 of the bottom panel 12. In this case, the other vertices may not have the locking structure 22 that forms the connecting structure between the first panel 14 and the second panel 16, or may have another locking structure. In that case, the first panel 14 and the second panel 16 may be joined using a joining means such as adhesive or tape, or may be joined using another locking structure.

[0033] In the present invention, it is preferable that two lock structures 22 are arranged, one at each of the two vertices, and it is more preferable that four lock structures 22 are arranged, one at each of the four vertices. 1, when the bottom panel 12 is a rectangle having four vertices, it is most preferable that the lock structures 22 be placed at all four vertices. In this case, when the first panel 14 and the second panel 16 are both folded upright relative to the bottom panel 12, the lock structures 22 at the four vertices simultaneously form connecting structures between the first panel 14 and the second panel 16 at all four vertices 32 of the bottom panel 12.

[0034] The locking structure 22 is composed of a flap portion 18 connected via a flap fold line 30 to the edge of the first panel 14 extending from one vertex 32 in a direction perpendicular to the first fold line 24, and a hook-shaped slit portion 20 provided within the second panel 16 on the edge side of the second panel 16, inside the edge of the second panel 16 extending in a direction perpendicular to the second fold line 26, and positioned outward from a position on the second fold line 26. 2, the flap portion 18 is connected to the side plate portion 34, which is provided between the first fold line 24 and the outer top plate fold line 38, via a flap fold line 30. The flap portion 18 has a flap base portion 18a that has the same width as the side plate portion 34, and a flap tip portion 18b that is narrowed by notches on both sides.

[0035] Preferably, flap tip 18b has a notch 18c formed on the side farther from second panel 16, the notch 18c being cut deeper toward second panel 16 on the base end side than on the tip side, giving the tip a slightly pointed shape. As a result, even if first panel 14 returns due to a reaction force after flap tip 18b is inserted into gap 54, notch 18c reliably engages with the upper side of slit 20 (particularly second cut portion 20b), and first panel 14 with the return formed can open more, i.e., be opened, relative to bottom panel 12, improving stackability of the box (package) in a pre-assembled state. On the other hand, flap tip portion 18b may have cutout portion 18d formed on the side closer to second panel 16, the cutout portion 18d being parallel to the edge of flap base portion 18a. This makes it easier for first panel 14 and flap tip portion 18b to fall toward second panel 16, thereby making it possible to enlarge gap 54 after flap tip portion 18b is inserted. As a result, flap tip portion 18b can be smoothly inserted into gap 54. As a result, cutout portion 18d has the same effect as cutout portion 18c on the side farther from second panel 16.

[0036] Meanwhile, the slit portion 20 is configured in a hook shape from a first cut portion 20a that rises from the end of the second fold line 26 on the third fold line 28 side toward the outside of the second panel 16, and a second cut portion 20b that is continuous with the first cut portion 20a, bends at a substantially right angle, and extends toward the inner top panel fold line 52b. The second cut portion 20b is on the same line as the inner top panel fold line 52b, and forms the end of the inner top panel fold line 52b. When the second panel 16 is bent and raised relative to the bottom panel 12 at the second fold line 26 and the third fold line 28, the surface of the hook-shaped portion of the slit section 20 surrounded by the first cut portion 20a and the second cut portion 20b is pressed from the inside (front surface side) to the outside (back surface side), thereby opening the slit section 20 as shown in FIG. 3. That is, the hook-shaped portion of the slit section 20 moves toward the back surface side, opening the first cut portion 20a and the second cut portion 20b, thereby opening the slit section 20 on the back surface side of the blank 10 and separating it from the side panel end portion 48a and the inner top panel portion 50, forming a gap portion 54 and a second panel pressing portion 56. Details will be described later; for example, if an assembly jig 60 (described later) is used, the surface of the hook-shaped portion of the slit section 20 is pressed from the inside (front surface side) by the protrusion 86 of the pressing tool 64.

[0037] When the first panel 14 bends at the first fold line 24 and rises up, the flap tip 18b of the flap portion 18 rotates toward the second panel 16 and is inserted into the gap 54 formed in the slit portion 20 from the back side (outside) of the second panel 16. In this way, as shown in Figure 4, when the first panel 14 and the second panel 16 rise vertically from the bottom panel 12, the flap tip 18b passes through the back side of the side panel end 48a and is completely inserted into the slit portion 20, and the connecting structure between the first panel 14 and the second panel 16 when assembled into a box is formed at the vertex 32 of the bottom panel 12 on the back side of the second panel 16 of the blank 10. On the other hand, the second panel pressing portion 56 is a hook-shaped portion surrounded by the first cut portion 20a and the second cut portion 20b of the opened slit portion 20, and because it is opened, a force acts to return to its original shape due to the rigidity of the material of the blank 10, so that it can press the flap tip portion 18b inserted into the gap portion 54 from the back surface side. When the pressing force from the protrusion 86 of the pressing tool 64 is released, the pressing force on the flap tip portion 18b by the second panel pressing portion 56 becomes stronger. As a result, the flap tip portion 18b of the flap portion 18 and the slit portion 20 are securely locked together.

[0038] In order for the flap tip 18b to be inserted into the slit portion 20 and its gap 54, as shown in Figure 2, when the width of the flap tip 18b is A, the length of the flap portion 18 is B, the distance from the third fold line 28 to the second cut portion 20b of the slit portion 20 (the height of the slit portion 20) is C, and the distance from the first fold line 24 to the end of the inside (the inner top panel fold line 52b side) of the first cut portion 20a of the slit portion 20 is D, the following formula (1) must be satisfied. C≧A D≧B ………(1)

[0039] In the blank 10, the width A of the flap tip portions 18b is narrower than the height C of the slit portions 20, so when the force pressing the first panel 14 and the second panel 16 from the back side to raise them vertically is removed, a reaction force acts from the front side to the back side of the first panel 14 and the second panel 16, causing them to open slightly. In this case, as shown in Figure 5, the flap tip portions 18b inserted into the gap 54 rotate slightly upward, but they do not come out of the slit portions 20 because they engage with the end of the second cut portion 20b of the slit portions 20 that constitute the gap 54 on the inner top panel portion 50 side. Furthermore, on the side of flap tip 18b farther from second panel 16, a notch 18c is formed in which the base end is cut deeper toward second panel 16 than the tip side, and the tip has a slightly pointed shape on the side farther from second panel 16. Therefore, when inserted into gap 54, the side of flap tip 18b farther from second panel 16 faces upward, and the slightly pointed notch 18c of flap tip 18b strongly engages with the end of second cut portion 20b on the inner top panel 50 side, causing it to spread slightly outward relative to bottom panel 12.

[0040] As described above, by inserting the flap tip portion 18b of the flap portion 18 that constitutes the locking structure portion 22 into the gap portion 54 of the slit portion 20, a connection can be formed between the first panel 14 and the second panel 16. Therefore, assembly does not require skill, and even someone unfamiliar with assembly work can assemble it easily and quickly. Thus, as shown in Figure 6, the blank 10 of the present invention can stand on its own as a box in a slightly open, pre-assembled state in which the first panel 14 and the second panel 16 stand vertically upright from the bottom panel 12. As a result, the blank 10 of the present invention can be used in this state to store articles, thereby improving work efficiency.

[0041] Furthermore, in the blank 10 of the present invention, the connecting structure between the first panel 14 and the second panel 16 is formed on the back side of the blank 10 by inserting the flap portion 18 provided on the first panel 14 into the gap 54 of the slit portion 20 provided in the second panel 16, so that the boxes in the pre-assembled state can be easily stacked when they are stored. In the connecting connection of the locking structure portion 22 of the blank 10 of the present invention, the flap portion 18 is inserted into the gap 54 of the slit portion 20, so that the connecting and connecting members such as the flap portion 18 and the slit portion 20 do not protrude either inside or outside the pre-assembled box, and the first panel 14 and the second panel 16 are set upright while spreading outward relative to the bottom panel 12, creating a sliding effect that allows the next pre-assembled box to be smoothly placed on top of the pre-assembled box below, allowing them to be stacked.

[0042] In the blank 10 of the present invention, the second fold line 26 formed between the side panel end portion 48a of the second panel 16 and the bottom panel 12 is formed slightly, for example, about 2 mm closer to the bottom panel 12 than the third fold line 28 formed between the side panel center portion 48b of the second panel and the bottom panel 12, as described above. 7(a), when the second panel 16 is not raised much, for example at about 15°, the third fold line 28 is positioned slightly, for example 2 mm outward (upward in the figure), from the second fold line 26. Therefore, when the second panel 16 is raised and the side panel end portion 48a is bent at the second fold line 26 and the side panel central portion 48b is bent at the third fold line 28 relative to the bottom panel 12, the side panel end portion 48a is bent closer to the front side (toward the viewer in the figure) relative to the side panel central portion 48b. As a result, a space (gap portion 54) is easily generated, and a second panel pressing portion 56 is formed.

[0043] Furthermore, as shown in FIG. 7(b), when the second panel 16 rises even more, for example to about 30°, the side panel end 48a bends further toward the front (toward the viewer in the figure) relative to the side panel center 48b, thereby further expanding the space (void portion 54) and increasing the pressing force of the second panel pressing portion 56. As a result, after the flap tip 18b is inserted into the gap 54, the reaction force causes the first panel 14, which has a return, to open more, i.e., be open, relative to the bottom panel 12, thereby improving the stackability of the box (packaging body) in a pre-assembled state.

[0044] In the illustrated example of the blank 10, the flap tip 18b of the flap portion 18 has notches 18c and 18d on both sides in the width direction of the flap portion 18, making its width narrower than the width of the flap base 18a. This makes it easier to insert the flap tip 18b into the gap 54 of the slit portion 20, and also makes it difficult for the flap tip 18b to slip out of the slit portion 20 by engaging with the slit portion 20. However, the present invention is not limited to this. 8(a) may be used instead of the flap portion 18. This flap portion 18A has a shape in which the notch 18c on the side of the flap base 18a of the flap portion 18 farther from the second panel 16 remains as it is, and the notch 18d on the side closer to the second panel 16 is eliminated.

[0045] 8(b) may be used instead of the flap portion 18. This flap portion 18B does not have the notches 18c and 18d on both sides of the flap portion 18, and has a shape with the same width overall. Here, it goes without saying that both flap portion 18A and flap portion 18B must satisfy the above formula (1) when the width of their tip portions is A. By satisfying the above formula (1), the tip portions of flap portions 18A and 18B can be inserted into gap portion 54 of slit portion 20, and are engaged with slit portion 20 to prevent them from slipping out of slit portion 20.

[0046] In the illustrated example, the flap portion 18 is inserted from the back side of the second panel 16 into the gap 54 of the slit portion 20 provided in the second panel 16, thereby forming a connecting structure on the back side of the second panel 16. However, the present invention is not limited to this, and conversely, the flap portion 18 may be inserted from the front side of the second panel 16 into the gap 54 of the slit portion 20 provided in the second panel 16, thereby forming a connecting structure on the front side of the second panel 16. In this case, the second fold line 26 formed between the side panel end portion 48a of the second panel 16 and the bottom panel 12 needs to be formed slightly farther from the bottom panel 12 than the third fold line 28 formed between the side panel center portion 48b of the second panel and the bottom panel 12. Furthermore, in the illustrated example of blank 10, flap portion 18 is provided on first panel 14 and slit portion 20 is provided on second panel 16, but the present invention is not limited to this, and conversely, flap portion 18 may be provided on second panel 16 and slit portion 20 may be provided on first panel 14. In other words, first panel 14 of blank 10 in the illustrated example may be the second panel, and second panel 16 may be the first panel. In addition, in the blank 10 shown in FIG. 1, the shapes of the first panel 14 and the second panel 16 may be changed as appropriate depending on the contents to be packaged inside.

[0047] Next, a second example of the blank according to the first embodiment of the present invention will be described. FIG. 9 is a plan view schematically showing a second example, which is another example of the blank according to the first embodiment of the present invention. The blank 11 of the present invention shown in Figure 9 differs from the blank 10 of the present invention shown in Figure 1 in that the shapes of the components are different, and therefore different reference symbols are used for the same components. However, apart from the differences in the lock structure and its surrounding structure and function, the blanks have basically the same configuration and function, and therefore detailed explanations of the components will be omitted. The blank 11 shown in Figure 9 has a rectangular bottom panel 13, a pair of first panel panels 15 connected to the outside of a pair of opposing sides of the bottom panel 13, and a pair of second panel panels 17 connected to the outside of the other pair of opposing sides of the bottom panel 13. The blank 11 further has four locking structure portions 23, each of which has four flap portions 19 connected to the edge of each of the pair of first panel members 15 on both sides, and four slit portions 21 provided in the second panel member 17 corresponding to the four flap portions 19, respectively.

[0048] A total of two first fold lines 25 are formed between the first panel 15 and the bottom panel 13, i.e., on each of two sides of one of the bottom panels 13. The first panel 15 is connected to the sides of the bottom panel 13 via the first fold lines 25 so as to be foldable. Between the second panel 17 and the bottom panel 13, that is, on the other two sides of the bottom panel 13, second fold lines 27 are formed. On one side of the second panel 17 of the bottom panel 13, a mountain-shaped opening 41 is formed from the center of the second fold line 27 toward the other side of the second panel 17 so that the packaging box can be opened by cutting it after it has been formed into a packaging box. The center of the second fold line 27 that forms the edge of this opening 41 is also formed as a perforation line 41a, and a perforation line 41b is also formed on the edge of the mountain-shaped opening 41 that faces the other side of the second panel 17. In addition, a crease is made on the side of the opening 41 toward the other second panel 17, forming an opening fold line 41c, which makes it easy to cut the opening 41 from the perforation lines 41a and 41b and open the packaging box.

[0049] A flap fold line 31 is formed between the flap portion 19 and one edge of the first panel 15 that extends in a direction perpendicular to the first fold line 25 . The ends of the first fold lines 25 are the ends of one side of the bottom plate 13, and therefore form vertices 33 of the bottom plate 13. Therefore, both end portions of the two first fold lines 25 form four vertices 33 of the bottom plate 13. The four flap portions 19 are adjacent to the four vertices 33 of the bottom panel 13, respectively.

[0050] 1, the second fold line 27 and the flap fold line 31 are arranged so as to be perpendicular to the grain direction 43 of the cardboard sheet (shown by the stripes in the circle in FIG. 9), and the first fold line 25 is arranged so as to be parallel to the grain direction 43 of the cardboard sheet. As mentioned above, the grain direction of the cardboard sheet is not particularly limited, but by arranging the second fold line 27 and the flap fold line 31 so as to be perpendicular to the grain direction 43 of the cardboard sheet, there is a strong repulsive force when the second panel 17 is folded at the second fold line 27 and when the flap portion 19 is folded at the flap fold line 31, so that the slit portion 21 is easily opened, the gap portion 55 (see FIG. 12) can be widened, and the flap portion 19 can be easily inserted into the slit portion 21, improving insertability.

[0051] The two first panels 15 have similar configurations and include a rectangular (first) side panel 35 that forms a side panel of the packaging box, and a roughly rectangular outer (first) top panel 37 that forms part of the top panel of the packaging box. Here, the top panel has the same shape as the bottom panel 13. The side panel 35 and the outer top panel 37 are continuous via an outer (first) top panel fold line 39 that extends parallel to the first fold line 25. In the first panel 15, the insides of the side panel 35 and the outer top panel 37 (the sides closer to the side panel 35) have the same width as the adjacent sides of the bottom panel 13, but the outsides of the outer top panel 37 (the sides farther from the side panel 35) are narrower than the sides of the bottom panel 13, facilitating assembly into a packaging box. The first panel 15 may have any shape as long as it can be assembled into a packaging box. Although the side panel portions 35 of the two first panel members 15 and the two outer top panel portions 37 have the same shape, the two outer top panel portions 37 may have any shape as long as they can form a top panel, and as shown in Figure 9, they may each have the shape of half a top panel, or one may have a larger shape so that they overlap each other to form a top panel.

[0052] Each of the second panels 17 has the same configuration and includes a (second) side panel portion 49 that forms a side panel of the packaging box, and an inner (second) top panel portion 51 that forms part of the top panel of the packaging box. In the second panel 17, the insides (sides closer to the side panel portion 49) of the side panel portion 49 and the inner top panel portion 51 are narrower than the sides of the adjacent bottom panel 13, making it easier to assemble the packaging box. The outside of the inner top panel portion 51 (side farther from the side panel portion 49) becomes even narrower, and a circular notch is formed at the outer apex. The side plate portions 49 are composed of side plate end portions 49a provided on both outer sides, and a side plate center portion 49b provided in the center portion between the slit portions 21 on both sides of the second panel 17. Both outer side panel end portions 49a of the side panel portion 49 are continuous with the inner top panel portion 51 via an inner (second) top panel fold line 53a that extends parallel to the second fold line 27, and are formed by bending the second fold line 27 and the inner top panel fold line 53a. Meanwhile, the inner side panel central portion 49b of the side panel portion 49 is continuous with the inner top panel portion 51 via an inner (second) top panel fold line 53b that extends parallel to the second fold line 27 and is formed between the slit portions 21, and is formed by bending the second fold line 27 and the inner top panel fold line 53b. The inner top panel fold line 53a may be formed slightly closer to the bottom panel 13 than the inner top panel fold line 53b, or may be formed on the same line.

[0053] In addition, outer top panel fold line 39, inner top panel fold line 53a, and inner top panel fold line 53b may have fold lines or perforations formed therein. If perforations are formed, each may have perforations formed therein, and by reducing the rigidity, outer top panel 37 is easier to fold relative to side panel 35, and inner top panel 51 is easier to fold relative to side panel 49 (side panel end portion 49a and side panel center portion 49b). Incidentally, since inner top panel fold line 53a is short, the perforations therein are shorter in length and spacing than the perforations on outer top panel fold line 39 and inner top panel fold line 53b.

[0054] The blank 11 shown in Figure 9 has a locking structure 23 at the vertex 33 of the bottom panel 13, which is configured so that a connecting structure between the first panel 15 and the second panel 17 is formed when the first panel 15 and the second panel 17, which sandwich the vertex 33 of the bottom panel 13, are both folded so as to stand upright relative to the bottom panel 13, as is the case with the locking structure 22 of the blank 10 shown in Figure 2. The locking structure 23 is composed of a flap portion 19 connected via a flap fold line 31 to the edge of the first panel 15 extending from one vertex 33 in a direction perpendicular to the first fold line 25, and a hook-shaped slit portion 21 provided within the second panel 17 on the edge side of the second panel 17, inside the edge of the second panel 17, and extending from the second fold line 27 in a side panel portion 49 outward relative to the second fold line 27. Here, the locking structure 23 is arranged outward from a position spaced outward from the second fold line 27.

[0055] 10, the flap portion 19 is connected to the side plate portion 35, which is provided between the first fold line 25 and the outer top plate fold line 39, via a flap fold line 31. The flap portion 19 has a flap base portion 19a having the same width as the side plate portion 35, and a flap tip portion 19b that is narrowed by notches on both sides. On the side of flap tip 19b farther from second panel 17, notch 19c is formed, which is cut deeper toward second panel 17 on the base end side than on the tip side, giving the tip a slightly pointed shape. As a result, even if first panel 15 returns due to a reaction force after flap tip 19b is inserted into gap 55, notch 19c reliably engages with the upper side of slit 21 (first cut portion 21a and second cut portion 21b), and first panel 15 with the return formed can open more, i.e., be opened, relative to bottom panel 12, improving stackability of the box (package) in a partially assembled state.

[0056] That is, when the first panel 15 is bent along the first fold line 25 and not completely closed, the flap tip 19b on which the notch 19c is formed engages with the first cut portion 21a and / or the second cut portion 21b of the slit portion 21, which will be described later, thereby tilting the first panel 15. By tilting the first panel 15 in this manner, stackability can be improved. Furthermore, when the first panel 15 and the second panel 17 are closed, the flap tip 19b on which the notch 19c is formed is covered by the first panel 15 and the second panel 17. This ensures that the flap 19 is securely locked by the first panel 15 and the second panel 17 and can be securely locked by the locking structure 23. The second panel 17 can embrace, or restrain, the flap tip 19b whether or not it is bent. Meanwhile, a recess 19d is formed in the edge of the flap base 19a of the flap tip 19b, closer to the second panel 17. The recess 19d is recessed parallel to the flap fold line 31 on the flap base 19a side, and is recessed at an angle toward the tip on the flap tip 19b side. When the flap portion 19 is inserted into a slit 21 (described later), the recess 19d of the flap portion 19 and a fishhook-shaped bent portion 21d at the lower end of the first cut portion 21a of the slit 21 engage with (contact with) each other. Note that the presence of the recess 19d in the flap portion 19 eliminates the need for contact. The recess 19d in the flap portion 19 reduces the cut area in the flap portion 19, allowing the flap portion 19 to be inserted into the slit 21 and securely locked in the slit 21 without reducing the strength of the flap portion 19.

[0057] Meanwhile, the slit portion 21 is configured in a hook shape from a position slightly inward from the end of the second fold line 27, slightly outward (outside) from the second fold line 27, tilting slightly upward and to the right in FIG. 10 toward the outside of the second panel 17, to a position on the extension of the inner top fold line 53b, and consisting of a first cut portion 21a having a fishhook-shaped bent portion 21d at its lower end, and a second cut portion 21b continuing from the first cut portion 21a, bending at a substantially right angle from its upper end in a hook shape toward the inner top fold line 53b. The slit portion 21 may further be configured with a third cut portion 21c that tilts upward and to the left in FIG. 10 from the end of the center of the second cut portion 21b. The second cut portion 21b is substantially collinear with the inner top fold line 53b and forms the end of the inner top fold line 53b. 10 may have a short cut portion (hereinafter referred to as a vertical cut portion) 21b' at the tip on the center side that slopes slightly downward at a right angle toward the second fold line 27. By having the vertical cut portion 21b', the slit portion 21 can form a bending line from the vertical cut portion 21b' in a direction perpendicular to the second fold line 27, i.e., in the vertical direction in FIG. 10, when the flap tip portion 19b is inserted. This allows the gap 55 to be formed wider.

[0058] By arranging the slit portion 21 outward from a position spaced apart from the second fold line 27, the flap tip portion 19b is locked by the lower end of the first cut portion 21a and the bent portion 21d when inserted into the slit portion 21. This prevents the flap tip portion 19b from collapsing onto the bottom plate 13, and allows the side plate portions 35 and 49 to be installed approximately perpendicular to the bottom plate 13. This prevents a reduction in the storage space of the box when assembled into a box. When the second panel 17 is bent at the second fold line 27 relative to the bottom panel 13 and raised up, if the surface of the hook-shaped portion surrounded by the first cut portion 21a and the second cut portion 21b of the slit portion 21, or the third cut portion 21c is further included, the surface of the hook-shaped portion surrounded by these and the third cut portion 21c is pressed from the inside (the front side) to the outside (the back side) in Fig. 11, thereby opening the slit portion 21 as shown in Fig. 11 and Fig. 12. That is, the hook-shaped portion of the slit portion 21 moves to the back side, and the first cut portion 21a and the second cut portion 21b, or in addition to these, the third cut portion 21c, open, thereby opening the slit portion 21 on the back side of the blank 11, and the slit portion 21 is separated from the side panel end portion 49a and the inner top panel portion 51, forming a gap portion 55 and a second panel pressing portion 57. For example, if an assembly jig 60 described later is used, the surface of the hook-shaped portion of the slit portion 21 is pressed from the inside (surface side) by the protrusion 86 of the pressing tool 64.

[0059] When the first panel 15 is bent at the first fold line 25 and rises up, the flap tip 19b of the flap portion 19 rotates toward the second panel 17 and is inserted into the gap 55 formed in the slit 21 from the back side (outside) of the second panel 17. In this way, as shown in Figure 11, when the first panel 15 and the second panel 17 rise vertically from the bottom panel 13, the flap tip 19b passes through the back side of the side panel end 49a and is completely inserted into the slit 21, and the connecting structure between the first panel 15 and the second panel 17 when assembled into a box is formed at the vertex 33 of the bottom panel 13 on the back side of the second panel 17 of the blank 11. On the other hand, the second panel pressing portion 57 is a hook-shaped portion surrounded by the first cut portion 21a and the second cut portion 21b of the opened slit portion 21, or a hook-shaped portion surrounded by these and also by the third cut portion 21c, and because it is opened, a force acts to return to its original shape due to the rigidity of the material of the blank 11, so that it can press from the back surface side against the flap tip portion 19b inserted into the gap portion 55. When the pressing force from the protrusion 86 of the pressing tool 64 is released, the pressing force from the second panel pressing portion 57 against the flap tip portion 19b becomes stronger. Thus, in the locking structure 23, the flap tip 19b of the flap portion 19 is inserted into the gap 55 of the slit portion 21 and engaged with its second cutting portion 21b, and the flap portion 19 and the slit portion 21 are securely locked together by the pressure applied to the flap tip 19b by the second panel pressing portion 57 of the slit portion 21. The conditions for inserting the flap tip 19b into the slit portion 21 and its gap portion 55 are the same as the conditions for inserting the flap tip 18b into the slit portion 20 and its gap portion 54 described above, so detailed explanations will be omitted.

[0060] In the examples shown in Figures 9 to 12, the slit portion 21 is composed of the first cut portion 21a, the second cut portion 21b, and the third cut portion 21c, but the present invention is not limited to this, and the slit portion 21 may be composed of the first cut portion 21a and the second cut portion 21b, and may not include the third cut portion 21c. When the third cut portion 21c is provided in the slit portion 21, the third cut portion 21c is formed outward (outside) from the inner top panel folding line 53b and in the upper left in Fig. 10, so that the slit portion 21 can be opened starting from the first cut portion 21a, the second cut portion 21b, the third cut portion 21c, and the bent portion 21d. Also, the flap portion 19 is inserted into the slit portion 21 so as to rotate from the top in Fig. 10 starting from the vertex 33. The third cut portion 21c is located outward (outside) from the inner top panel folding line 53b and in the upper left in Fig. 10, which allows the opening area of ​​the first cut portion 21a and the third cut portion 21c to be widened. This makes it easier to insert the flap portion 19 into the slit portion 21 compared to when the third cut portion 21c is not present.

[0061] Next, the second example of the blank according to the first embodiment of the present invention is basically configured as described above, but the locking structure portion is not limited to the configuration of the locking structure portion 23 shown in Figures 9 to 12, and may be modified in various ways depending on the required functions. First, a modified example of the lock structure applied to the second embodiment of the blank of the present invention will be described. Note that, in the following, the same components are given the same numbers and their description will be omitted. FIG. 13 is an enlarged plan view showing a modified example (first modified example) of the lock structure part applied to the blank of the present invention shown in FIG. The lock structure 23A shown in FIG. 13 is composed of a flap portion 19A and a slit portion 21. Flap portion 19A has flap base 19a and flap tip 19e. Unlike flap tip 19b of flap portion 19 shown in Fig. 10, flap tip 19e has a flat tip, but like flap tip 19b, it has notch 19c and recess 19d, and therefore provides similar functions and effects. In addition, since the tip of flap tip 19e of flap portion 19A is flat, it can be easily inserted into slit portion 21. On the other hand, the slit portion 21 has a first cutting portion 21a, a second cutting portion 21b, and a third cutting portion 21c, similar to the case of the flap portion 19, and has the same action and effect as the lock structure portion 23 (see Figure 10) when the slit portion 21 has the third cutting portion 21c. That is, in the locking structure portion 23A, the flap tip portion 19e of the flap portion 19A is inserted into the gap portion (not shown) of the slit portion 21 and engaged with its second cutting portion 21b, and the flap tip portion 19e is pressed against it by the second panel pressing portion 57 of the slit portion 21, thereby reliably locking the flap portion 19A and the slit portion 21 together. Furthermore, as shown in Figure 13, the slit portion 21 may have a vertical notch 21b' at the tip of the second cutting portion 21b, similar to the slit portion 21 shown in Figure 10, and exhibits the same action and effect as the second embodiment shown in Figures 10 to 12.

[0062] Next, FIG. 14 is an enlarged plan view showing another modified example (second modified example) of the lock structure part applied to the blank of the present invention shown in FIG. The lock structure 23B shown in FIG. 14 is composed of a flap portion 19B and a slit portion 21A. The flap portion 19B has a flap base 19a and a flap tip 19f. Note that the flap tip 19f has a protrusion 19g that protrudes from the end of the flap base 19a in a direction parallel to the flap fold line 31 on the side farther from the second panel 17, and has a recessed portion 19d on the side closer to the second panel 17, similar to the flap tip 19e shown in FIG. 13. Therefore, it can be said that the flap tip 19f does not have the notch 19c of the flap tip 19e shown in FIG. 13, but has a protrusion 19g instead. Note that the base of the protrusion 19g has a protrusion fold line 19h that is parallel to the end of the flap base 19a. On the other hand, like the first cut portion 21a of the slit portion 21 shown in Figure 13, the slit portion 21A is configured in a hook shape from the end of the second fold line 27 and a position slightly outward (outside) from the second fold line 27, and rises outward (outside) of the second panel 17, sloping slightly to the upper right in Figure 14 and beyond the extension of the inner top panel fold line 53b, and has a fishhook-shaped bent portion 21d at its lower end, a second cut portion 21f that rises sloping to the upper left in Figure 14 from the apex of the first cut portion 21e, and a third cut portion 21g that extends from the apex of the second cut portion 21f parallel to the inner top panel fold line 53b toward the center of the second panel 17 and has the fishhook-shaped bent portion 21d at its tip.

[0063] In the slit portion 21A, openings are formed starting from the lower end of the first cut portion 21e and the tip of the third cut portion 21g, which is the upper end, to form gaps (not shown). Therefore, the opening area (gap) can be made wider compared to the slit portion 21 shown in FIGS. 10 and 13. In this way, in slit portion 21A, first cut portion 21e and second cut portion 21f rise beyond the extension line of inner top panel fold line 53b and are close to the end face of second panel 17, making it possible to make slit portion 21A easy to open even if protrusion 19g of flap portion 19B is large. As a result, second panel pressing portion 57A of slit portion 21A can be efficiently pressed by pressing tool 64 of assembly jig 60, which will be described later, to provide a wide opening area for slit portion 21A. Therefore, the flap portion 19B having the protrusion 19g can be properly inserted into the slit portion 21A. Furthermore, protrusion 19g of flap portion 19B can be securely locked in slit portion 21A. Thus, because protrusion 19g is provided on flap portion 19B, when first panel 15 and second panel 17 are folded, respectively, flap portion 19B is inserted into slit portion 21A, and inner top panel 51 of second panel 17 is folded along inner top panel fold line 53b, protrusion 19g also folds along protrusion fold line 19h, and thus protrusion 19g bends approximately perpendicular to flap portion 19B inserted into slit portion 21A. This locks protrusion 19g into slit portion 21A, preventing flap portion 19B from slipping out of slit portion 21A. As a result, in the locking structure portion 23B, the flap tip portion 19f of the flap portion 19B is inserted into the gap portion (not shown) of the slit portion 21A and engaged with its third cut portion 21g, and the flap tip portion 19f is pressed by the second panel pressing portion 57A of the slit portion 21A, thereby securely locking the flap portion 19B and the slit portion 21A together. The second cut portion 21f of the slit portion 21A curves and connects the first cut portion 21e, which is approximately perpendicular to the second fold line 27, and the third cut portion 21g, which is approximately parallel to the second fold line 27, and is not particularly limited to this, and may be of any type as long as it can connect the two.

[0064] Next, FIG. 15 is an enlarged plan view showing another modified example (third modified example) of the lock structure part applied to the blank of the present invention shown in FIG. The lock structure 23C shown in FIG. 15 is composed of a flap portion 19C and a slit portion 21A. The flap portion 19C has a flap base 19a and a flap tip 19i, and has a recess 19k parallel to the flap fold line 31 between the flap base 19a and the flap tip 19i on the side closer to the second panel 17. Note that, like the flap tip 19e shown in FIG. 13, the upper tip of the flap tip 19i is flat and parallel to the flap fold line 31, so that it protrudes toward the side closer to the second panel 17 and forms a semicircular protrusion 19n at its protruding end. A notch 19j is formed on the side of the flap tip 19i farther from the second panel 17. In other words, the protruding flap tip 19i is formed to be approximately horizontal.

[0065] Therefore, the edge of the recessed portion 19k at the flap tip portion 19i can be engaged with the lower end of the slit portion 21A, i.e., the lower side of the first cut portion 21e, and the bent portion 21d, and the protrusion portion 19n can increase the contact area with the second panel pressing portion 57A. In this way, the area where the flap portion 19C is caught in the slit portion 21A can be increased, and the flap portion 19C can be prevented from slipping out of the slit portion 21A. In this way, because the protrusion 19n of the flap tip 19i is formed substantially horizontally, when the flap portion 19C rotates from the first fold line 25, the flap portion 19C is inserted substantially vertically into the first cut portion 21e of the slit portion 21A, which is formed substantially vertically. As a result, the protrusion 19n of the flap tip 19i is brought into wide contact with the lower end of the slit portion 21A, i.e., the lower side of the first cut portion 21e, and is widely pressed against the second panel pressing portion 57A. As a result, in the locking structure portion 23C, the flap portion 19C and the slit portion 21A (the first cut portion 21e thereof) are securely engaged, and the flap portion 19C and the slit portion 21A are securely locked together by the pressure on the flap tip portion 19i by the second panel pressing portion 57A of the slit portion 21A.

[0066] Next, FIG. 16 is an enlarged plan view showing another modified example (fourth modified example) of the lock structure part applied to the blank of the present invention shown in FIG. A lock structure 23D shown in FIG. 16 is composed of a flap portion 19D, a slit portion 21A, and an internal folding line 51a formed above the slit portion 21A. Here, flap portion 19D has flap base 19a and flap tip 19m. Note that flap tip 19m can be said to be formed by attaching protrusion 19g of flap portion 19B of lock structure portion 23B of the second modified example shown in Fig. 14 to notch 19j of flap tip 19i, which includes protrusion 19n of flap portion 19C of lock structure portion 23C of the third modified example shown in Fig. 15. In other words, flap tip 19m has protrusions 19n and 19g on both sides. In addition, the slit portion 21A, together with the flap portion 19C as shown in FIG. 15, constitutes the lock structure portion 23C of the third modified example, and, together with the flap portion 19B as shown in FIG. 14, constitutes the lock structure portion 23B of the second modified example. Therefore, the lock structure 23D, which is composed of the flap portion 19D having the flap tip 19m and the slit portion 21A, has the same functions and effects as those obtained by the combination of the protruding flap tip 19i and the slit portion 21A in the third modified example, and the combination of the protruding portion 19g and the slit portion 21A in the second modified example. These functions and effects are described in detail in each modified example, so a detailed description thereof will be omitted here.

[0067] Next, the internal fold line 51a is a fold line that rises perpendicularly from the tip of the third cut portion 21g of the slit portion 21A to the inner top fold line 53b within the inner top plate portion 51 and reaches the outer edge of the inner top plate portion 51. In this way, the internal fold line 51a is formed above the slit portion 21A, and therefore the slit portion 21A can be made to open further. Here, when the second panel 17 is bent starting from the second fold line 27, the stress applied to the second fold line 27 is concentrated on the internal fold line 51a, so that the internal fold line 51a is easily bent, and the slit portion 21A opens starting from the internal fold line 51a and the end of the first cut portion 21e of the slit portion 21A. By folding the inner folding lines 51a inward, the opening area of ​​the slit portion 21A, that is, the opening areas of the first cut portion 21e, the second cut portion 21f, and the third cut portion 21g can be widened. As a result, even flap portion 19D having flap tip portion 19m with two protrusions 19n and 19g can be reliably inserted into slit portion 21A, and flap portion 19D and slit portion 21A (first cut portion 21e) are reliably locked together. Thus, in lock structure portion 23D, flap portion 19D and slit portion 21A are reliably locked together by the pressing of flap tip portion 19m by second face plate pressing portion 57A of slit portion 21A.

[0068] Next, FIG. 17 is an enlarged plan view showing another modified example (fifth modified example) of the lock structure part applied to the blank of the present invention shown in FIG. The locking structure portion 23E shown in Figure 17 is composed of a flap portion 19E, a slit portion 21B, an internal fold line 51a formed above the slit portion 21A, and a V-shaped recess (V cut) 51b formed at the outer end of the second panel 17 (the upper end in Figure 17). The flap portion 19E has a flap base 19a and a flap tip 19o. On the side closer to the second panel 17, a recess 19p is formed between the flap base 19a and the flap tip 19o, and is inclined (toward the lower left in the figure) so as to approach the flap fold line 31 toward the side closer to the second panel 17. As a result, flap tip 19o has, on the side closer to second panel 17, protrusion 19q that is inclined (toward the lower left in the figure) so as to approach flap fold line 31, and, on the side farther from second panel 17, protrusion 19g that protrudes parallel to flap fold line 31. Here, protrusion 19q has a configuration similar to protrusion 19n of flap portion 19C of lock structure 23C of the third modified example shown in FIG. 15 and protrusion 19n of flap portion 19D of lock structure 23D of the fourth modified example shown in FIG. 16, and has the same action and effect. Note that protrusion 19g is the same as protrusion 19g of flap portion 19B of lock structure 23B of the second modified example shown in FIG. 14 and protrusion 19g of flap portion 19D of lock structure 23D of the fourth modified example shown in FIG. 16, and therefore description thereof will be omitted.

[0069] On the other hand, slit portion 21B, like first cut portion 21e of slit portion 21A shown in FIG. 16, is configured in a hook shape from a first cut portion 21h that starts at the end of second fold line 27 and is slightly away from second fold line 27, and rises at an angle toward the outside (outside) of second panel 17 and toward the center (upper left in FIG. 17), then reverses before reaching the extension of inner top panel fold line 53b and slopes away from the center (upper right in FIG. 17), rising beyond the extension of inner top panel fold line 53b, and has fishhook-shaped bent portion 21d at its lower end, second cut portion 21f that rises at an angle toward the upper left in FIG. 17 from the apex of first cut portion 21h, and third cut portion 21g that extends from the apex of second cut portion 21f parallel to inner top panel fold curve 53b toward the center of second panel 17 and has fishhook-shaped bent portion 21d at its tip. The internal fold line 51a is the same as the internal fold line 51a shown in FIG. The V-cut 51b is formed at the outer end (upper end in FIG. 17) of the inner top panel portion 51 of the second panel 17, starting from the outer end (upper end in FIG. 17) of the inner fold line 51a.

[0070] In the lock structure 23E, the flap tip 19o of the flap portion 19E is inserted so as to abut against the slit portion 21B and the second face plate pressing portion 57B. In this way, the inclined recess 19p of the flap portion 19E fits into the inclined portion at the lower end of the first cut portion 21h of the slit portion 21B, and the flap tip 19o is hooked onto the lower end of the first cut portion 21h. In this way, the flap portion 19E can be securely locked into the slit portion 21B. 17, even if a return force is generated when the flap portion 19E rotates about the first fold line 25, the flap tip portion 19o is engaged with the lower end of the first cut portion 21h of the slit portion 21B as a return. When opening the slit portion 21B, the slit portion 21B of the second panel 17 is pressed by a pressing tool 64 of the assembly jig 60, which will be described later, to open the slit portion 21B easily. Furthermore, the pressing force of the pressing tool 64 of the assembly jig 60 (described later) on the second panel 17 acts to bend the second panel 17 starting from the second fold line 27. When the pressing force of the pressing tool 64 presses the second panel pressing portion 57B of the slit 21B, the respective forces are applied to the internal fold line 51a via the V-cut 51b. Thus, the internal fold line 51a facilitates the widening of the slit 21B. Furthermore, the V-cut 51b, which concentrates stress on the V-cut 51b, facilitates the folding of the internal fold line 51a. This widens the slit 21B, making it easier to insert the flap 19E into the slit 21B. After insertion, it becomes difficult for the flap 19E to slip out, as described above. That is, the V-cut 51b facilitates the opening of the slit 21B, making it easier to insert the flap 19E into the opened slit 21B. Therefore, in the locking structure portion 23E, the flap tip portion 19o of the flap portion 19E is inserted into the slit portion 21B and engaged with its first cutting portion 21h, and the flap tip portion 19o is pressed by the second panel pressing portion 57B of the slit portion 21B, thereby reliably locking the flap portion 19E and the slit portion 21B together.

[0071] Next, FIG. 18 is an enlarged plan view showing another modified example (sixth modified example) of the lock structure part applied to the blank of the present invention shown in FIG. The locking structure portion 23F shown in Figure 18 is composed of a flap portion 19F, a slit portion 21C, an internal fold line 51a formed above the slit portion 21C, and a V-shaped recess (V cut) 51b formed at the outer end of the second panel 17 (the upper end in Figure 18). Here, the flap portion 19F has a flap base 19a and a flap tip 19r. The flap portion 19F has a configuration substantially similar to that of the flap portion 19C shown in Fig. 15, and has a recess 19s parallel to the flap fold line 31 between the flap base 19a and the flap tip 19r. The flap tip 19r has a protrusion 19t that protrudes from the side closer to the second panel 17, and a notch 19j on the side farther from the second panel 17. In other words, the protruding flap tip 19r is formed to be substantially horizontal. Here, the flap base 19a, flap tip 19r, recess 19s, protrusion 19t, and notch 19j of flap portion 19F correspond to the flap base 19a, flap tip 19i, recess 19k, protrusion 19n, and notch 19j of flap portion 19C shown in Figure 15, although there are slight differences in shape.

[0072] On the other hand, slit portion 21C, like first cut portion 21e of slit portion 21A shown in Figure 15, is configured in a hook shape from the end of second fold line 27 and a position slightly outward (outside) from second fold line 27, and unlike first cut portion 21a, rises outward (outside) of second panel 17 in a direction approximately perpendicular to inner top panel fold line 53b, beyond the extension of inner top panel fold line 53b, and has fishhook-shaped bent portion 21d at its lower end, second cut portion 21f rises from the apex of first cut portion 21i at an angle to the upper left in Figure 14, and third cut portion 21g rises from the apex of second cut portion 21f parallel to inner top panel fold line 53b toward the center of second panel 17 and has fishhook-shaped bent portion 21d at its tip. It is preferable that the first cut portion 21i is formed in a direction approximately perpendicular to the top panel fold line 53b, but this is not particularly limiting, and it is sufficient that the lower end of the first cut portion 21i, which is on the side of the second fold line 27 (lower side in Figure 18) than the top panel fold line 53b, is formed in a direction approximately perpendicular.

[0073] Due to this configuration, the flap tip 19r of the flap portion 19F is inserted while abutting against the lower end of the slit portion 21C, that is, the first cutting portion 21i or its lower end, and the second face plate pressing portion 57C. When flap portion 19F rotates from first fold line 25 (baseline portion) as a starting point, first cut portion 21i is formed toward the outside of second panel 17 in a direction substantially perpendicular to inner top panel fold line 53b, and recessed portion 19s is formed parallel to flap fold line 31, so that flap tip portion 19r of flap portion 19F can be easily inserted while abutting against the lower end (first cut portion 21i or its lower end) of slit portion 21C, allowing for effective insertion and locking. As a result, ease of insertion and retention of flap portion 19F into slit portion 21C can be balanced, and the ease of insertion and difficulty of removal required for assembly of flap portion 19F and slit portion 21C can be maintained at a moderate level. The internal fold line 51a and the V-shaped recess (V cut) 51b have been described in detail in the description of the lock structure 23D shown in FIG. 16 and the lock structure 23E shown in FIG. 17, so their description will be omitted. Thus, in the locking structure portion 23F, the flap tip portion 19r of the flap portion 19F is inserted into the slit portion 21C and engaged with its first cutting portion 21i, and the flap tip portion 19r is pressed by the second panel pressing portion 57C of the slit portion 21B, thereby reliably locking the flap portion 19F and the slit portion 21C together. The second cut portions 21f of the slit portions 21A to 21C shown in FIGS. 15 to 18 are similar to the second cut portion 21f of the slit portion 21A shown in FIG.

[0074] Next, FIG. 19 is an enlarged plan view showing another modified example (seventh modified example) of the lock structure part applied to the blank of the present invention shown in FIG. A lock structure 23G shown in FIG. 19 is composed of a flap portion 19G and a slit portion 21D. The flap portion 19G has a flap base 19a and a flap tip 19u. In the flap tip 19u, a notch 19v is formed on the side farther from the second panel 17, and a notch 19w is formed on the side closer to the second panel 17. Therefore, the width of the part of the flap tip 19u, which is the middle part of the flap portion 19G and is close to the flap base 19a, is formed shorter than the width of the flap base 19a. Here, the notch 19w is formed so that the side of the notch 19w closer to the second panel 17 and the side of the flap base 19a closer to the second panel 17 are substantially parallel to each other. As a result, the flap portion 19G can be easily inserted into the slit portion 21D.

[0075] On the other hand, the slit portion 21D is located at a position slightly inside the center from the end of the second fold line 27, and starts from a position slightly outward (outside) from the second fold line 27, and rises toward the outside (outside) of the second panel 17, slanting slightly to the right and right in Figure 19, to a position on the extension of the inner top panel fold line 53b, and is composed of a first cut portion 21a having a fishhook-shaped bent portion 21d at its lower end, a short second cut portion 21j that is continuous with the first cut portion 21a, bends at an approximately right angle from its upper end in a hook-like shape, and extends in the same line as the inner top panel fold line 53b, a third cut portion 21k that is continuous with the second cut portion 21j and forms a step down on the side of the second fold line 27 and extends toward the inner top panel fold curve 53b, and a fourth cut portion 21m that is continuous with the third cut portion 21k and rises one step toward the inner top panel fold curve 53b in the same line as the second cut portion 21j. The second cut portion 21j and the fourth cut portion 21m are spaced apart by a predetermined distance and are positioned on the same line as the inner top panel folding line 53b.

[0076] When inner top panel 51 of second panel 17 is not closed, flap tip 19u where cutouts 19v and 19w are located is locked in third cut portion 21k that forms the center end of slit 21D. Therefore, when a box is constructed from blank 11 of the present invention, third cut portion 21k is positioned lower in Fig. 19 (toward second fold line 27) than second cut portion 21j and fourth cut portion 21m. Therefore, when flap portion 19G is inserted into and locked in slit 21D, the opening formed by first panel 15 and second panel 17 can be opened without being too wide, improving the stackability of the box. Furthermore, after flap tip 19u with cutouts 19v and 19w is inserted into third cutout 21k constituting the center end of slit 21D, when inner top panel 51 of second panel 17 is closed about inner top panel fold line 53a and inner top panel fold line 53b, flap tip 19u, which attempts to turn around about first fold line 25, is covered and securely locked by third cutout 21k. Therefore, flap 19G is securely locked to side panel 49 of second panel 17, and locking structure 23G can securely lock flap 19G to slit 21D by the second panel pressing portion 57D of slit 21D pressing flap tip 19u. As a result, return of first panel 15 and second panel 17 can be prevented.

[0077] Incidentally, the third cut portion 21k of the slit portion 21D of the lock structure portion 23G shown in Fig. 19 may be provided in the second cut portion 21b of the slit portion 21 of the lock structure portion 23 shown in Fig. 10 and the lock structure portion 23A shown in Fig. 13. In other words, the second cut portion 21b of the slit portion 21 may be changed to a configuration consisting of the second cut portion 21j, the third cut portion 21k, and the fourth cut portion 21m. Incidentally, the flap tip 19b of the flap portion 19 of the locking structure portion 23 shown in FIG. 10 and the flap tip 19e of the flap portion 19A of the locking structure portion 23A shown in FIG. 13 are locked by being inserted into the slit portion 21 and by being locked by the first cutting portion 20a and pressed by the second panel pressing portion 57, but in this case, the flap tip portions 19b and 19e cannot be covered.

[0078] In contrast, by providing a third cutting portion 21k in the second cutting portion 21b of the slit portion 21, the lock structure portion 23 shown in Figure 10 and the lock structure portion 23A shown in Figure 13 can obtain not only the respective actions and effects but also actions and effects similar to those of the third cutting portion 21k. In addition, in the flap tip portion 19b of the flap portion 19 of the locking structure portion 23 shown in Figure 10, the flap tip portion 19e of the flap portion 19A of the locking structure portion 23A shown in Figure 13, and the flap tip portion 19r of the flap portion 19G of the locking structure portion 23G shown in Figure 19, the side farther from the second panel 17 is a notch, and the notch portion 19c shown in Figures 10 and 13 is similar to the notch portion 19v shown in Figure 19. Therefore, by providing a third cut portion 21k in the slit portion 21, when the flap tip portions 19b and 19e having the notch portion 19c are inserted into the third cut portion 21k that forms the central end portion of the slit portion 21, and the inner top plate portion 51 of the second panel 17 is closed starting from the inner top plate fold curve 53a and the inner top plate fold curve 53b, the flap tip portions 19b and 19e that attempt to invert starting from the first fold curve 25 are covered and securely locked by the third cut portion 21k. The blank of the first embodiment of the present invention is basically configured as described above.

[0079] (Blank assembly jig) As described above, the blanks 10 and 11 of the first embodiment of the present invention can be assembled manually by a worker without requiring auxiliary materials or automated machinery, but can be assembled more efficiently by using a dedicated assembly jig. Below, a method for assembling the blank 10 having the above configuration will be described using a method using an assembly jig as a representative example. Figure 20 is a plan view schematically showing an example of a jig body of a blank assembly jig according to the second embodiment of the present invention, and Figure 21 is a plan view schematically showing an example of a pressing tool of a blank assembly jig according to the second embodiment of the present invention. The blank assembly jig of the present invention is used by combining the jig body shown in FIG. 20 with the pressing tool shown in FIG. 22 and 23 are respectively a front view and a side view of the jig main body shown in Fig. 20. Fig. 24 and 25 are respectively a front view and a side view of the pressing tool shown in Fig. 21. Fig. 26 is a plan view showing the state in which the blank shown in Fig. 1 is set (loaded) in the jig main body shown in Fig. 20.

[0080] The assembly jig 60 of the present invention comprises a jig body 62 into which the blank 10 is loaded, and a pressing tool 64 that presses the bottom plate 12 of the loaded blank 10 from above and pushes it into the jig body 62. The jig body 62 shown in Figure 20 is equipped with a connecting structure forming mechanism that bends the first panel 14 and the second panel 16 so that they stand upright relative to the bottom panel 12, thereby simultaneously forming a connecting structure between the first panel 14 and the second panel 16 at all points on the vertices of the bottom panel 12.

[0081] The connecting structure forming mechanism includes a flap guide mechanism 66 configured to fold the flap portion 18 at the flap fold line 30 when the bottom panel 12 of the blank 10 is pressed from the front side by the pressing tool 64 and pushed into the jig body 62, a first panel guide mechanism 68 that folds the first panel 14 at the first fold line 24, and a second panel guide mechanism 70 that folds the second panel 16 at the second fold line 26 and the third fold line 28 ahead of the first panel 14. The jig body 62 shown in Fig. 20 includes a substantially rectangular base plate 74 having a central opening 72 formed therein, the central opening 72 having an opening shape (rectangular) that fits the shape of the bottom plate 12 of the blank 10. The jig body 62 also includes four flap guide mechanisms 66 provided at the four upper corners of the base plate 74, two first panel guide mechanisms 68 provided between two adjacent flap guide mechanisms 66 in one direction (the up-down direction in Fig. 20), and four second panel guide mechanisms 70 provided adjacent to each flap guide mechanism 66 on the inside in a direction (the left-right direction in Fig. 20) perpendicular to the one direction.

[0082] As shown in Figures 20 to 22, each flap guide mechanism 66 is located on the second panel guide mechanism 70 side of four support pillars 76 that are arranged to stand at the four corners of the base plate 74, and has a flat flap support surface 66a that is arranged on the upper side of the support pillars 76 and supports each flap portion 18 from the lower surface, and a flap guide surface 66b that is arranged inside the flap support surface 66a (towards the central opening 72) and is inclined inward to slide and guide each flap portion 18 so that it is folded along the flap fold line 30. Each second panel guide mechanism 70 includes a second panel guide member 78 provided inside each flap guide mechanism 66 so as to stand on the base plate 74 . The second panel guide member 78 has a flat second panel support surface 78a on the upper surface above the support column 76, which supports one side portion of the second panel 16 from the lower surface, and a second panel guide surface 78b that is provided inside the second panel support surface 78a and is inclined inward to slide and guide one side portion of the second panel 16 so as to bend the second panel 16 at the second fold line 26 and the third fold line 28. Each flap portion 18 and each second panel 16 are folded approximately simultaneously by the flap guide mechanism 66 and the second panel guide member 78, respectively.

[0083] On the other hand, as shown in FIGS. 20 to 22, each first face plate guide mechanism 68 is composed of five cylinders 68a, 68b, 68c, 68d, and 68e that are provided between two support columns 76 arranged in the vertical direction so as to bridge the two columns. That is, both ends of the five cylinders 68a to 68e are supported by two support columns 76. As shown in FIG. 22, cylinder 68a is disposed at a height approximately midway on the inner plane of support column 76, along the outer edge of substrate 74 that is farthest from the central opening 72. Cylinder 68b is disposed at a height slightly lower than cylinder 68a, and closer to the central opening 72 of substrate 74. The three cylinders 68c, 68d, and 68e are disposed at equal intervals along the edge of central opening 72 between a position slightly lower than cylinder 68b and the position of substrate 74. As a result, the five cylinders 68a to 68e are arranged so as to be inclined inward (toward the central opening 72), and can sequentially come into contact with the surface of the first panel 14, sliding to guide the first panel 14 so as to bend it along the first fold line 24.

[0084] 21 has a substantially rectangular outer shape that fits the shape of the bottom plate 12 of the blank 10. The pressing tool 64 is configured by connecting a frame body 64b having an opening 64a therein with a connecting member 64c at the center. Note that the pressing tool 64 in the illustrated example is a frame body to reduce weight, but the present invention is not limited to this and may be a rectangular parallelepiped. As shown in Figures 21, 24, and 25, the pressing tool 64 has a substantially rectangular pressing bottom surface 80 on the pressing side, a side surface 82 on the first panel 14 side, a side surface 84 on the second panel 16 side, and a protrusion 86 provided in the central portion of the side surface 84.

[0085] The pressing bottom surface 80 must have a shape that is slightly smaller than the bottom plate 12 of the blank 10, but it is preferable that it has approximately the same shape. The side surface 82 is inclined upward with respect to the pressing bottom surface 80 so that the first panel 14 can be easily bent at the first folding line 24 and does not come into contact with the first panel 14 . The side surface 84 has a protrusion 86 so that it is perpendicular to the bottom pressing surface 80 . The protruding portion 86 presses the side plate central portion 48b between the slit portions 20 on both sides so that when the second panel 16 of the blank 10 is bent and raised, the slit portions 20 of the second panel 16 open to form the gap portion 54 and the second panel pressing portion 56. For this reason, the protruding portion 86 has a length corresponding to the length of the side plate central portion 48b between the slit portions 20 on both sides. The assembly jig 60 according to the second embodiment of the present invention is configured as described above.

[0086] Next, a method of assembling the blank 10 shown in FIG. 1 using an assembly jig 60 consisting of a jig body 62 shown in FIG. 20 and a pressing tool 64 shown in FIG. 21 will be described. When assembling the blank 10 using the assembly jig 60, first, the blank 10 is loaded (set) horizontally into the jig body 62, as shown in Fig. 26. Specifically, the four flap portions 18 are positioned on the flat flap support surfaces 66a of the four flap guide mechanisms 66, and the two opposing second panel plates 16 are supported by the flat second panel support surfaces 78a of the four second panel guide members 78. With the blank 10 loaded in the jig body 62, the bottom plate 12 of the blank 10 is pressed from above by a pressing tool 64 having a pressing bottom surface 80 with substantially the same planar shape as the bottom plate 12 of the blank 10.

[0087] 22 , the second panel 16 is first guided by contacting it against the second panel guide surface 78b of the second panel guide member 78, and then the second panel 16 is bent at the second fold line 26 and the third fold line 28 by the action of the inclined surface of the second panel guide surface 78b. Next, the second panel 16 is bent so as to stand perpendicular to the bottom panel 12 by the action of the tip surface of the second panel guide surface 78b and the side surface of the second panel guide member 78. At this time, the protrusions 86 on both side surfaces 84 of the pressing tool 64 press the side panel central portions 48b of the two second panels 16, opening the slit portions 20 on both sides of the side panel central portions 48b and forming the gap portion 54 and the second panel pressing portion 56. Meanwhile, at the same time, the flap portion 18 is brought into contact with the flap guide surface 66b of the flap guide mechanism 66 and guided therein, and then the flap portion 18 is bent along the flap folding line 30 by the action of the inclined surface of the flap guide surface 66b and the side surfaces of the support posts 76 that constitute the flap guide mechanism 66. Next, the flap portion 18 is bent so as to stand perpendicular to the first panel 14 by the action of the tip end surface of the flap guide surface 66b.

[0088] Next, the pressing tool 64 continues to press against the gap 54 and the slit portion 20 that forms the second panel pressing portion 56, and the bottom panel 12 is pressed down to the position of the column 68a of the first panel guide mechanism 68, causing the back surface of the first panel 14 to abut against the column 68a, and the first panel 14 begins to bend along the first fold line 24. Thereafter, the pressing tool 64 continues to press further, causing the back surface of the first panel 14 to abut against the column 68a, then against the column 68b, and then against the column 68c, that is, by the action of the first panel guide mechanism 68, the first panel 14 is bent along the first fold line 24 as shown in FIG. 3. At this time, as shown in FIG. 3, the flap portion 18 that was bent perpendicular to the first panel 14 rotates about the first fold line 24 and approaches the gap 54 of the opened slit portion 20.

[0089] Figure 27 shows the slit portion 20 of the second panel 16 in contact with the second panel guide member 78 of the second panel guide mechanism 70 and the flap portion 18 before insertion, viewed from the back side of the second panel 16. 27, the second panel guide member 78 contacts the second panel 16 on its side, and has a recess 88 formed in a concave shape below the contact surface. Therefore, this recess 88 makes it possible to form a gap 90 between the second panel guide member 78 and the rear surface of the second panel 16 near the slit portion 20 of the second panel 16. The flap portion 18 rotates around the first fold line 24 in response to the rising of the first panel 14, and thus enters the gap 90 formed between the second panel guide member 78 and the back surface of the second panel 16, and approaches the gap 54 of the opened slit portion 20. Furthermore, by positioning the cylinders 68a, 68b, 68c, 68d, and 68e of the first panel guide mechanism 68 below the second panel guide surface 78b of the second panel guide member 78 in the vertical direction of the assembly jig 60, the first panel 14 can be bent while rotating after the second panel 16.

[0090] After this, as pressure continues to be applied by the pressing tool 64, the first panel 14 rises further, and the flap portion 18 rotates further within the gap 90 around the first fold line 24, and is inserted into the void 54 of the slit portion 20 of the second panel 16. Furthermore, when pressure is continued with the pressing tool 64 and the first panel 14 is bent so that it stands upright relative to the bottom panel 12, the flap portion 18 is properly inserted into the gap 54 of the slit portion 20 of the second panel 16, as shown in Figure 4, and a connecting structure of the first panel 14 and the second panel 16 is formed by the lock structure portion 22 consisting of the flap portion 18 and the slit portion 20.

[0091] From this state, when further pressure is applied by the pressing tool 64, the blank 10 on which the connecting structure of the first panel 14 and the second panel 16 is formed is pushed downward from the central opening 72 of the base plate 74 of the jig body 62, and the blank 10 is released from the jig body 62. At this time, the first panel 14 tilts about the first fold line 24, and the second panel 16 tilts about the second fold line 26 and the third fold line 28, so that each of the first panel 14 and the second panel 16 returns to their original shape due to their own elasticity, and as a result, as shown in FIG. 5, the notched portion 18c of the flap tip 18b of the flap portion 18 engages with the upper side (the inner top panel portion 50 side) of the first cut portion 20a of the slit portion 20, preventing the flap tip 18b from coming out of the slit portion 20. In this way, a connecting and engaging structure is simultaneously formed between the first panel 14 and the second panel 16 at the four corners. In this way, a self-standing box (packaging box) in a partially assembled state, as shown in FIG. 6, can be formed.

[0092] In this way, in the box body in the pre-assembled state, as shown in Figure 6, each of the first panel 14 and each of the second panel 16 is in an expanded state with the tip extending outward, but the packaging box in the pre-assembled state is formed so that it can stand on its own with the bottom panel 12 in contact with the ground. Then, the inner top panel portion 50 of each second panel 16 is folded along the inner top panel fold lines 52a and 52b, and then the outer top panel portion 36a of one first panel 14a is folded along the outer top panel fold line 38, and the outer top panel portion 36b of the other first panel 14b is folded along the outer top panel fold line 38.Furthermore, the insertion piece 40 of one first panel 14a is inserted into the cutout portion 46 of the other first panel 14b, and the protruding piece 40b of the insertion piece 40 is engaged with the cutout portion 46, thereby obtaining a packaging box.

[0093] Thus, with the assembly jig 60 of the present invention, the connecting structure between the first panel 14 and the second panel 16 can be simultaneously formed at all points on the vertices of the bottom panel 12 by the simple operation of pressing the bottom panel 12 of the blank 10 loaded into the jig body 62 from above with the pressing tool 64, making it possible to make the blank 10 self-standing as a box in a pre-assembled state. Furthermore, because the blank 10 can be released from the jig body 62 through the central opening 72, the blank 10 can be assembled efficiently.

[0094] In addition, the jig body 62 is formed with a second panel guide member 78 that presses the blank 10 from the back side of the blank 10, and a gap portion 90 that is open as space is formed between the second panel 16 of the blank 10 and the second panel guide member 78. Therefore, by using the assembly jig 60 of the present invention, it is possible to open the slit portion 20 of the second panel 16 and form the gap portion 54 and the second panel pressing portion 56. This allows the flap tip portion 18b of the flap portion 18 to be inserted into the gap portion 54 and the slit portion 20 through the gap portion 90. As a result, the second panel pressing portion 56 presses the flap tip portion 18b inserted into the slit portion 20 from the back surface side, and the blank 10 can form a connecting structure that connects the first panel 14 and the second panel 16 with the locking structure portion 22. In this way, the blank 10 can form a connecting structure that connects the first panel 14 and the second panel 16 with the locking structure portion 22.

[0095] Furthermore, since the pressing tool 64 has a protrusion 86 formed on its side surface 84, it is possible to form a larger gap 54 in the slit portion 20. This makes it possible for the flap tip portion 18b to be easily inserted into the slit portion 20 and the gap 54. As a result, the first panel 14 can be more open relative to the bottom panel 12, which makes it possible to improve the stackability (ease of stacking) of the box body (packaging box) in a partially assembled state.

[0096] In the assembly jig 60 of the illustrated example, in order to reliably insert the flap portion 18 into the slit portion 20 from the back side of the second panel 16 in a blank 10 having a lock structure portion 22 on the back side of the second panel 16, a protrusion 86 is provided on the side surface 84 of the pressing tool 64 and a recess 88 is provided in the second panel guide member 78 of the jig body 62, thereby forming a gap 90 between the blank 10, but the present invention is not limited to this. When assembling a blank arranged with the lock structure portion 22 on the back side of the second panel 16, a protrusion may be provided on the second panel guide member 78 of the jig body 62 and a recess may be provided in the side surface 84 of the pressing tool 64 on the second panel side, opposite to the assembly jig 60 of the illustrated example, so as to form a gap between the blank 10.

[0097] The blank and blank assembly jig of the present invention have been described in detail above using embodiments, but the present invention is not limited to these embodiments, and various improvements or modifications may be made within the scope of the present invention. [Explanation of symbols]

[0098] 10, 11 blank 12, 13 Bottom plate 14, 14a, 14b, 15 First plate 16, 17 Second face plate 18, 18A, 18B, 19, 19A, 19B, 19C, 19D, 19E, 19F, 19G Flap section 18a, 19a Flap base 18b, 19b, 19e, 19f, 19i, 19m, 19o, 19r, 19u Flap tip 18c, 18d, 19c, 19j, 19v, 19w Notch 19d, 19k, 19p, 19s recess 19g, 19n, 19q, 19t protrusion 19h protruding curve 20, 21, 21A, 21B, 21C, 21D Slit section 20a, 21a, 21e, 21h, 21i 1st cutting section 20b, 21b, 21f, 21j 2nd cutting section 21b' Cut section (vertical cut section) 21c, 21g, 21k 3rd cutting section 21d Bend part 21m 4th cutting section 22, 23, 23A, 23B, 23C, 23D, 23E, 23F, 23G Lock structure 24, 25 1st folding curve 26, 27 2nd fold curve 28 3rd fold curve 30, 31 Flap fold curve 32, 33 Vertices 34, 35, 48, 49 Side plate part 36a, 36b, 37 Outer (first) top plate 38, 39 Outer (first) top panel fold curve 40 Insert 41 Opening 41a, 41b Cutting line 41c Opening fold curve 40a recess 40b Projecting piece 42 Insertion piece folding curve 43 Grain direction 44 Opening tear line 46 Notch 48a, 49a Side plate end 48b, 49b Center part of side plate 50, 51 Inner (second) top plate 51a Internal fold line 51b V-shaped recess (V cut) 52a, 52b, 53a, 53b (second) top board fold curve 54, 55 void area 56, 57, 57A, 57B, 57C, 57D 2nd face plate pressing part 60 Assembly jig 62 Jig body 64 Pressing tool 64a aperture 64b Frame 64c Connecting member 66 Flap guide mechanism 66a Flap support surface 66b Flap guide surface 68 First face plate guide mechanism 68a, 68b, 68c, 68d, 68e Cylinders 70 Second face plate guide mechanism 72 Central opening 74 PCB 76 Pillar 78 Second panel guide member 78a Second face plate support surface 78b Second panel guide surface 80 Pressing bottom surface 82, 84 Side 86 Protrusion 88 recess 90 Gap

Claims

1. A blank for forming a box body, comprising: a polygonal bottom plate; a first plate connected to one of two adjacent sides of the bottom plate so as to be bendable, and a second plate connected to the other side so as to be bendable; the bottom panel has at least one locking structure configured such that when the first panel and the second panel are folded together, a connection structure between the first panel and the second panel is formed at a vertex of the bottom panel; The first panel has a first top panel fold curve that is spaced a predetermined distance outward from and parallel to a first fold curve that is provided between the bottom panel and the first panel, a first side panel portion that is provided between the first fold curve and the first top panel fold curve and forms a side panel of the box body, and a first top panel portion that is continuous with the first side panel portion and is provided outward from the first top panel fold curve and forms a part of the top panel of the box body, The second panel has a second top panel fold curve that is spaced apart from and parallel to the second fold curve between the bottom panel and the second panel, a second side panel portion that is formed between the second fold curve and the second top panel fold curve and that forms a side panel of the box body, and a second top panel portion that is continuous with the second side panel portion and that is formed outward from the second top panel fold curve and that forms a part of the top panel of the box body, the locking structure is provided on an edge of the first side plate and is configured by a flap portion that is provided continuously in a direction along the first fold line, and a hook-shaped slit portion that is provided within the second panel on the edge side of the second panel, inside the edge of the second panel, and extends outward from the second side plate with respect to the second fold line; the slit portion is disposed outward from a position on the second fold line, Between the bottom panel and the second panel, in addition to the second fold line provided on the edge side of the second panel, there is a third fold line on the inside from the position where the slit portion is provided, the second panel is pressed from the rear surface side and bent relative to the bottom panel along the second fold line and the third fold line, The third fold line is formed at a position farther from the bottom plate than the second fold line, In a state in which the second panel is folded relative to the bottom panel along the second fold line and the third fold line, a portion of the second panel adjacent to the slit portion is pressed from the inside to the outside, thereby opening the slit portion, the opened portion becoming a gap portion, and the adjacent portion forming a second panel pressing portion, When the first panel is folded back, the flap portion is folded back, and the tip of the flap portion is inserted into the slit portion and the void portion, and is pressed by the second panel pressing portion to form the connecting structure.

2. The first panel is folded back toward the front surface, the second panel is pressed from the rear surface side and bent along the second folding line relative to the bottom panel, The flap portion is folded back toward the front surface along a flap fold line extending perpendicular to the first fold line, the flap portion is formed so that a tip end thereof is inserted into the slit portion and the gap portion on the back surface side of the second face plate, The blank according to claim 1 , wherein the locking structure portion is configured such that the connecting structure between the first panel and the second panel is formed on the back side of the second panel at the apex of the bottom panel.

3. The slit portion is disposed outward from a position spaced outward from the second fold line, 3. The blank according to claim 1, wherein the second fold line extends from one edge to the other edge of the second panel.

4. The blank according to any one of claims 1 to 3, wherein the second panel further has a cut portion at an outer end of the slit portion.

5. The blank according to any one of claims 1 to 4, wherein a tip of the flap portion is engaged by a part of the slit portion of the second panel when the first panel and the second panel are folded.

6. The blank according to any one of claims 1 to 5, wherein the flap portion has a notch formed at a tip end on a side farther from the edge of the second panel.

7. The blank according to any one of claims 1 to 6, wherein the flap portion has a notch formed at a tip thereof closer to the edge of the second panel.

8. An assembly jig for a blank according to any one of claims 1 to 7, a jig body into which the blank is loaded, and a pressing tool that presses the bottom plate of the blank from the front surface side into the jig body, The jig body has a first panel guide mechanism that presses the first panel of the blank from the back surface side of the blank to bend it along the first fold line when the pressing tool presses the bottom panel of the blank from the front surface side to push it into the jig body, a second panel guide mechanism that presses the second panel of the blank from the back surface side to bend it along the second fold line, and a flap guide mechanism that presses the flap portion of the blank from the back surface side to bend it along a flap fold line extending in a direction perpendicular to the first fold line, the second face plate guide mechanism is configured to form a gap portion serving as a space between the second face plate and the second face plate guide mechanism when pressing the second face plate, The bottom panel of the blank placed on the jig body is pressed from the front surface side by the pressing tool and pushed into the jig body, and first, the second panel guide mechanism presses the second panel to bend it along the second fold line and the third fold line, and then, in a state where the second panel guide mechanism presses the adjacent portion from the inside to the outside by the pressing tool, the slit portion is opened, and the opened portion becomes the gap portion, and the adjacent portion forms the second panel pressing portion, and at the same time, the flap guide mechanism presses the flap portion to bend it relative to the first panel along the flap fold line, Next, the first panel guide mechanism presses the first panel to bend it along the first fold line, thereby rotating the flap portion bent at the flap fold line along the second panel, inserting the tip of the flap portion into the slit portion and the void portion through the gap portion, and pressing with the second panel pressing portion from the back surface side, thereby forming the connecting structure between the first panel and the second panel at the apex of the bottom panel.

9. 9. The assembly jig according to claim 8, wherein the pressing tool has a protrusion on a side surface thereof for making the gap larger.

Images