JP7501231B2 - Packaging box - Google Patents

Description

The present invention relates to a box-shaped packaging box for storing items.

Conventionally, there are packaging boxes that can be assembled into a box shape by folding a single cardboard sheet to accommodate an item to be contained. For example, the following Patent Document 1 discloses a cardboard packaging box in which a pair of inner flaps arranged opposite each other have tongues formed on a pair of outer flaps arranged opposite each other, which are inserted into insertion holes formed on each of the inner flaps to connect the two and form a bottom. In this case, the inner and outer flaps have inclined edges formed on the tongues to prevent the tongues from slipping out of the insertion holes, and the tip edges of the protrusions formed in the insertion holes are each inclined with respect to the grain direction of the core, which is perpendicular to the direction in which the corrugations of the core of the cardboard sheet are formed.

JP 2009-149332 A

However, in the packaging box described in Patent Document 1, the inclination angle of the tip edge of the protrusion formed in the insertion hole is small and is essentially parallel to the grain direction of the core, so there is a problem that the strength of the protrusion is low and the function of preventing the tongue from falling out is not fully exerted over a long period of time. In this case, in the packaging box described in Patent Document 1, the inclination angle of the inclined edge formed on the tongue relative to the grain direction is large, so the strength of the inclined edge is extremely high compared to the strength of the protrusion, which is also one of the factors that damage the protrusion.

The present invention has been made to address the above problem, and aims to provide a packaging box that can effectively prevent the insertion part inserted into the insertion opening from falling out over a long period of time.

In order to achieve the above object, the present invention is characterized in that a packaging box made of a cardboard sheet includes a tubular body portion having a pair of side walls and a pair of end walls, and a closing surface portion closing at least one opening of the body portion, the closing surface portion including a pair of inner flaps connected to each edge portion of the pair of side walls, and a pair of outer flaps connected to each edge portion of the pair of end walls and overlapping each outer surface of the pair of inner flaps, the pair of outer flaps each having a pair of insertion portions, the pair of inner flaps each having a pair of insertion openings into which the insertion portions are respectively inserted, the pair of insertion openings each having an opening side engagement edge at an end edge on the pull-out direction side of the insertion portions respectively inserted into the insertion openings, and the pair of insertion The insertion portion has an insertion portion side engaging edge on part of its outer peripheral edge which contacts the opening side engaging edge when the insertion portion is inserted into the insertion opening, and the opening side engaging edge and the insertion portion side engaging edge each extend at an angle of 30° or more and 50° or less with respect to the grain direction of the core of the cardboard sheet, and the insertion opening has a front end edge formed by extending in a direction perpendicular to the insertion direction at the front side of the insertion portion's inner peripheral edge in the insertion direction, and an opening flap provided within the insertion opening and connected to the inner flap, and which can be tilted in and out of the insertion opening using the part connected to the inner flap as a fulcrum, and the opening side engaging edge is formed directly connected to the end of the part of the inner flap to which the opening flap is connected and the front end edge, respectively.

According to the features of the present invention configured as described above, the packaging box has an opening side engaging edge and an insertion side engaging edge for preventing the insertion part from slipping out of the insertion opening, each extending at an angle of 30° or more and 50° or less with respect to the grain direction of the core perpendicular to the corrugation direction of the core of the cardboard sheet, so that the insertion part and the insertion opening can be prevented from being damaged by being pressed against each other with a strong force. As a result, the packaging box can effectively prevent the insertion part of the outer flap inserted into the insertion opening formed in the inner flap from slipping out for a long period of time. Also, according to this configuration, the packaging box has both ends of the opening side engaging edge directly connected to the front end edge formed by extending in a direction perpendicular to the insertion direction of the insertion part at the inner peripheral edge of the insertion opening and the end of the opening flap that can be tilted in and out of the insertion opening with the part connected to the inner flap as a fulcrum, so that the insertion opening can be configured compactly and simply.

Another feature of the present invention is that in the packaging box, the opening side engagement edge and the insertion side engagement edge are each formed to extend within an angle range of 45°±5° relative to the grain direction of the core.

According to the features of the present invention configured in this way, the packaging box is formed with the opening side engagement edge and the insertion part side engagement edge each extending within an angle range of 45°±5° relative to the grain direction of the core, and according to experiments conducted by the inventors, damage to the insertion part and the insertion opening which are pressed against each other is effectively suppressed, and the insertion part can be effectively prevented from falling out for a long period of time.

Another feature of the present invention is that the opening side engagement edge of the packaging box extends at an angle so that the end on the outer periphery side of the packaging box is located forward of the inner end of the packaging box in the insertion direction into the insertion opening of the insertion part.

According to the features of the present invention configured in this way, the packaging box is formed to extend at an angle so that the end of the outer periphery of the packaging box at the opening side engagement edge is located further forward in the insertion direction of the insertion part into the insertion opening than the inner end of the packaging box, so that the insertion part can be inserted in a sufficiently inclined position (lying down position) from a position separated from the insertion opening, making the insertion operation easier.

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Another feature of the present invention is that in the packaging box, the outer flap has a notch formed by cutting out a part of its outer periphery in a concave shape, and the insertion part side engagement edge is formed in a state exposed within the notch.

According to the features of the present invention configured in this way, the packaging box has a notch cut into a part of the outer peripheral edge of the outer flap, and the insertion part side engagement edge is formed in a state where it is exposed within the notch. Therefore, the insertion part side engagement edge can be easily positioned opposite the opening side engagement edge, and by placing a finger in the notch, the insertion part can be easily lifted up and removed from the insertion opening.

Another feature of the present invention is that in the packaging box, the insertion portion side engagement edge is formed by a linear cut that extends inward from the outer peripheral edge of the outer flap and is covered by a portion that faces this cut.

According to the features of the present invention configured in this way, the insertion part side engagement edge of the packaging box is formed by a linear cut extending inward from the outer peripheral surface of the outer flap and is covered by the portion facing this cut, so that the contact portion between the insertion part side engagement edge and the opening side engagement edge is prevented from being exposed, and the insertion part side engagement edge can be effectively prevented from coming off the opening side engagement edge. Also, by preventing the contact surface between the insertion part side engagement edge and the opening side engagement edge from being exposed, the packaging box eliminates unevenness around the insertion part side engagement edge, and can prevent objects facing the inner and outer flaps from getting caught.

Another feature of the present invention is that in the packaging box, the cut is formed such that the inner tip portion of the outer flap is bent and extended along a curve to form a relief portion.

According to the features of the present invention configured in this manner, the packaging box has a relief portion formed at the tip of the notch that extends and bends in a curve, so that when the engagement edge on the insertion portion side comes into contact with the engagement edge on the opening side and the notch opens, it is possible to prevent the tip of the notch from cracking and splitting .

1 is a perspective view showing an outline of the external configuration of a packaging box according to the present invention, as viewed from the lid side. 2 is a perspective view showing the outline of the external configuration of the packaging box shown in FIG. 1 as viewed from the bottom side. FIG. 2 is a plan view showing the external configuration of a packaging box-forming sheet body obtained by unfolding the cardboard sheet that constitutes the packaging box shown in FIG. 1 . FIG. FIG. 4 is a perspective view showing a schematic external configuration of the packaging box forming sheet body shown in FIG. 3 . 4 is a partially enlarged plan view showing details of the insertion opening and an engagement edge on the opening side shown in FIG. 3. [0023] FIG. 4 is a partially enlarged plan view showing details of the insertion portion and an engagement edge on the insertion portion side shown in FIG. 3 . FIG. 5 is a perspective view showing a state in which an assembly process has progressed for the packaging box forming sheet body shown in FIG. 4. FIG. 8 is a perspective view showing a state in which an assembly process has progressed for the packaging box forming sheet body shown in FIG. 7. FIG. (A) and (B) show the assembly process of the sheet body for forming the packaging box shown in Figure 3, where (A) is a partial plan view that shows, in outline, the state just before the bottom outer flap is inserted into the bottom inner flap, and (B) is a partial plan view that shows in outline the state after the bottom outer flap has been inserted into the bottom inner flap. FIG. 11 is a partial plan view showing the external configuration of a packaging box forming sheet body according to a modified example of the present invention in an unfolded state. (A) and (B) show bottom inner flaps in a sheet body for forming a packaging box according to a modified example of the present invention, where (A) is a partial plan view showing generally the external configuration of the bottom outer flap, and (B) is a partial plan view showing generally the state in which the bottom outer flap is inserted into the bottom inner flap.

Hereinafter, an embodiment of the packaging box according to the present invention will be described with reference to the drawings. FIG. 1 is a perspective view showing an outline of the external configuration of the packaging box 100 according to the present invention as viewed from the lid 103 side. FIG. 2 is a perspective view showing an outline of the external configuration of the packaging box 100 shown in FIG. 1 as viewed from the bottom 101 side. FIG. 3 is a plan view showing the external configuration of the packaging box forming sheet body 105 in which the cardboard sheet constituting the packaging box 100 shown in FIG. 1 is unfolded. FIG. 4 is a perspective view showing a schematic external configuration of the packaging box forming sheet body 105 shown in FIG. 3. In addition, in each of the drawings referred to in this embodiment and each of the modified examples, the folds in the unfolded state are shown by dashed lines. In addition, in each of the drawings referred to in this embodiment and each of the modified examples except FIG. 3, only the main symbols are attached to facilitate understanding, and other symbols are appropriately omitted.

This packaging box 100 is a container that holds various products, parts, materials, food, and other items (not shown) for transport or storage, and is mainly composed of a rectangular parallelepiped with one bottom 101, four outer peripheral walls 102, and one lid 103. In this case, the bottom 101 is the part on which the item is placed, and is formed in a rectangular shape in a plan view. The outer peripheral walls 102 are parts that stand up from the outer edge of the bottom 101 and surround the periphery of the item, and are each formed in a rectangular shape. The lid 103 is the part that covers the item, and is formed in a rectangular shape in a plan view.

This packaging box 100 is assembled by folding a packaging box forming sheet body 105, which is made of a single cardboard sheet, in mountain or valley folds to form a box body that is rectangular in plan view and has a low height. Note that this packaging box 100 may have shapes other than a rectangular parallelepiped, such as a cube, or various polygonal shapes such as a hexagon in plan view, a circle (including an oval), a sector shape, or various irregular shapes.

(Configuration of packaging box 100)
The sheet body 105 for forming a packaging box is composed of a single cardboard sheet extending in a strip shape, and mainly includes a pair of side walls 111, 112, a pair of end walls 114, 115, a pair of bottom inner flaps 120, 130, a pair of bottom outer flaps 140, 150, a pair of lid inner flaps 161, 162 and a pair of lid outer flaps 163, 164.

In this case, the side walls 111, 112, end walls 114, 115, bottom inner flaps 120, 130, bottom outer flaps 140, 150, lid inner flaps 161, 162, and lid outer flaps 163, 164 are formed in a single cardboard sheet constituting the packaging box forming sheet body 105 so that the grain direction of the core (not shown ) constituting the cardboard sheet extends in the vertical direction of the packaging box 100 (horizontal direction in FIG. 3 ). Here, the grain direction of the core is the width direction of the cardboard sheet that is perpendicular to the direction in which the flutes (wave shape) of the cardboard sheet are formed (vertical direction in FIG. 3). In FIG. 3 , the circle C drawn on the side wall 111 indicates the grain direction of the cardboard sheet constituting the packaging box forming sheet body 105 (similar to FIGS. 7 to 9).

The pair of side walls 111, 112, together with the pair of end walls 114, 115, constitute the outer peripheral wall 102 of the packaging box 100. When the packaging box 100 is assembled, the pair of side walls 111, 112 are provided in an upright state at positions facing each other on the bottom 101, which is formed in a rectangular shape when viewed from the bottom of the packaging box 100. The side walls 111 and 112 are formed to have the same shape, so the following description will mainly focus on the side wall 111.

The side wall 111 is one of the four outer walls 102 of the packaging box 100, and is formed in a rectangular shape in a plan view. More specifically, the side wall 111 is one of the two outer walls 102 that form the long side of the packaging box 100, which is formed in a rectangular parallelepiped shape. The side wall 111 is formed with a joint piece 113, an end wall 114, a bottom inner flap 120, and a lid inner flap 161, each of which is formed via lines 111a, 111b, 111c, and 111d.

The lines 111a, 111b, 111c, and 111d are formed in a linear manner to facilitate accurate folding of the joint piece 113, the end wall 114, the bottom inner flap 120, and the lid inner flap 161 relative to the side wall 111. In this case, the line 111a is formed between the side wall 111 and the joint piece 113. The line 111b is formed in a position opposite the line 111a and is formed between the side wall 111 and the end wall 114. The line 111c is formed between the side wall 111 and the bottom inner flap 120. The line 111d is formed in a position opposite the line 111c and is formed between the side wall 111 and the lid inner flap 161.

The joining piece 113 is a portion for joining the side wall 111 to the end wall 115, and is formed by protruding from the end face of the side wall 111. More specifically, the joining piece 113 protrudes from the end face of the side wall 111 by the same width, and is formed by extending so as to face a part of the bottom inner flap 120 and a part of the lid inner flap 161, respectively.

The side wall 112 that forms a pair with this side wall 111 has end walls 114, 115, bottom inner flaps 130, and lid inner flaps 162 formed via lines 112a, 112b, 112c, and 112d, respectively.

The pair of end walls 114, 115, together with the pair of side walls 111, 112, constitute the outer peripheral wall 102 of the packaging box 100. The pair of end walls 114, 115 are provided in an upright state at opposing positions on the bottom 101, which is formed in a rectangular shape when viewed from the bottom of the packaging box 100, when the packaging box 100 is assembled. The end walls 114 and 115 are formed in the same shape, so the following description will focus mainly on the end wall 114.

The end wall 114 is one of the four outer peripheral walls 102 of the packaging box 100, and is formed in a rectangular shape in a plan view. More specifically, the end wall 114 is one of the two outer peripheral walls 102 that form the short side of the packaging box 100, which is formed in a rectangular parallelepiped shape. A bottom outer flap 140 and a lid outer flap 163 are formed on this end wall 114 via lines 114a and 114b, respectively.

The lines 114a and 114b are formed to extend linearly and are intended to facilitate accurate folding of the bottom outer flap 140 and the lid outer flap 163 relative to the end wall 114. In this case, the line 114a is formed between the end wall 114 and the bottom outer flap 140. The line 114b is formed at a position opposite the line 114a and is formed between the end wall 114 and the lid outer flap 163.

The end wall 115 that pairs with this end wall 114 has a bottom outer flap 150 and a lid outer flap 164 formed by lines 115a and 115b, respectively.

The pair of bottom inner flaps 120, 130, together with the pair of bottom outer flaps 140, 150, constitute the bottom 101 on which the contents are placed. In this case, the bottom inner flap 120 and the bottom inner flap 130 are formed to have the same shape, so the description will be mainly focused on the bottom inner flap 120.

The bottom inner flap 120 is a part that forms half of the bottom 101 of the packaging box 100, and is formed in a rectangular shape in a plan view. In this case, the shape of the bottom inner flap 120 is appropriately determined according to the shape of the packaging box 100. A pair of insertion openings 121, 124 are respectively formed in this bottom inner flap 120. In this case, the pair of insertion openings 121, 124 are formed line-symmetrically with respect to each other, so the insertion opening 121 will be mainly described.

As shown in FIG. 5, the insertion opening 121 is a portion into which the insertion portion 141 described later is inserted to hold the bottom outer flap 140, and is configured as a long-hole-shaped through hole extending in the short side direction perpendicular to the long side of the bottom inner flap 120. That is, the insertion opening 121 is formed as a long hole extending parallel to the grain direction L of the core of the cardboard sheet that constitutes the packaging box forming sheet body 105. This insertion opening 121 is mainly configured to have a front end edge 121a, an opening side engagement edge 122, and an opening flap 123.

The front edge 121a is a portion formed forward in the insertion direction of the insertion portion 141 that is inserted into the insertion opening 121, and is formed in a straight line extending parallel to the grain direction L of the core of the cardboard sheet. One end side of this front edge 121a extends further forward in the insertion direction of the insertion portion 141, and then connects to the opening flap 123 via a lateral escape portion 121b that extends in an arc shape backward in the insertion direction (the direction in which the insertion portion 141 is pulled out). The other end side of the front edge 121a is connected to the opening side engagement edge 122.

The opening side engagement edge 122 is a portion that prevents the insertion portion 141 from coming out of the insertion opening 121 by contacting and facing the insertion portion side engagement edge 142 of the insertion portion 141 inserted into the insertion opening 121. This opening side engagement edge 122 is formed to extend linearly at an angle α of 45° with respect to the grain direction L of the core of the cardboard sheet so as to face the direction in which the insertion portion 141 is pulled out. The opening side engagement edge 122 has an end opposite to the end connected to the front edge 121a at both ends that is connected to the opening flap 123.

The opening flap 123 is a part that covers the insertion opening 121 so as to be freely opened and closed, and is formed in the same shape as the planar shape of the insertion opening 121. This opening flap 123 is connected to the bottom inner flap 120 via the connecting part 123a at the part that faces the front edge 121a of the insertion opening 121. In other words, the opening flap 123 is supported by the bottom inner flap 120 so as to tilt inward and outward of the insertion opening 121 with the connecting part 123a as a fulcrum.

The insertion opening 121 is formed at a position facing the insertion portion 141 of the bottom outer flap 140 when the packaging box forming sheet body 105 is assembled into the packaging box 100. The insertion opening 124 that forms a pair with this insertion opening 121 has a front edge 124a that is line-symmetrical with the front edge 121a, the side escape portion 121b, the opening side engagement edge 122, the opening flap 123, and the connecting portion 123a, a side escape portion 124b, the opening side engagement edge 125, the opening flap 126, and the connecting portion 126a, and is formed at a position facing the insertion portion 144 of the bottom outer flap 140 when the packaging box forming sheet body 105 is assembled into the packaging box 100. The insertion portion 151 described later is inserted into this insertion opening 124.

The bottom inner flap 130, which forms a pair with this bottom inner flap 120, is configured with an insertion opening 121, a front edge 121a, a side clearance 121b, an opening side engagement edge 122, an opening flap 123, a connecting portion 123a, an insertion opening 124, a front edge 124a, a side clearance 124b, an opening side engagement edge 125, an opening flap 126, and a connecting portion 126a, which are linearly symmetrical with the insertion opening 131, a front edge 131a, a side clearance 131b, an opening side engagement edge 132, an opening flap 133, a connecting portion 133a, an insertion opening 134, a front edge 134a, a side clearance 134b, an opening side engagement edge 135, an opening flap 136, and a connecting portion 136a.

In this case, the insertion opening 131 is formed at a position opposite the insertion portion 144 of the bottom outer flap 140 when the packaging box forming sheet body 105 is assembled into the packaging box 100. Also, the insertion opening 134 is formed at a position opposite the insertion portion 154 of the bottom outer flap 150 when the packaging box forming sheet body 105 is assembled into the packaging box 100.

The pair of bottom outer flaps 140, 150, together with the pair of bottom inner flaps 120, 130, constitute the bottom 101 on which the contents are placed. In this case, the bottom outer flap 140 and the bottom outer flap 150 are formed to have the same shape, so the description will be mainly focused on the bottom outer flap 140.

The bottom outer flap 140 is a portion that covers a portion of each of the bottom inner flaps 120, 130 that constitute the bottom 101 of the packaging box 100, and is formed in a shape that is close to a rectangle in a plan view. In this case, the shape of the bottom outer flap 140 is appropriately determined according to the shape of the packaging box 100. This bottom outer flap 140 is formed with a pair of insertion portions 141, 144, a central recess 147, and a line 148. In this case, the pair of insertion portions 141, 144 are formed line-symmetrically with respect to each other, so the insertion portion 141 will be mainly described.

The insertion portion 141 is a portion that connects the bottom outer flap 140 to the bottom inner flaps 120 and 130 by being inserted into the insertion opening 121 described above, and is formed to protrude forward in the insertion direction of the insertion portion 141 on one side of both ends of the free end side of the bottom outer flap 140. In this case, the insertion portion 141 is formed so that the tip portion 141a extends in a straight line parallel to the direction perpendicular to the grain direction L of the core of the cardboard sheet (the direction in which the flutes are formed). The corner portion of one end of the insertion portion 141 is rounded in an arc shape, and the insertion portion side engagement edge 142 and the cutout portion 143 are connected to each other. In addition, the other end of both ends of the insertion portion 141 is connected to the central recess 147.

As shown in FIG. 6, the insertion part side engagement edge 142 is a portion that prevents the insertion part 141 from slipping out of the insertion opening 121 by contacting the opening side engagement edge 122 formed in the insertion opening 121 while facing it, and is formed to extend inward from the side end face of the bottom outer flap 140. More specifically, the insertion part side engagement edge 142 is formed to extend linearly at an angle β of 45° with respect to the grain direction L of the core of the cardboard sheet so as to be exposed on the front side in the pull-out direction of the insertion part 141. In this case, the insertion part side engagement edge 142 is formed to be approximately the same length as the opening side engagement edge 122.

The cutout portion 143 is a portion for forming a space in front of the insertion portion side engaging edge 142, and is composed of the insertion portion side engaging edge 142 and a cutout facing surface 143a that is linearly symmetrical with respect to the insertion portion side engaging edge 142. As a result, the cutout portion 143 is formed in a shape that is cut out in a substantially triangular shape in a plan view on the side end surface of the bottom outer flap 140.

The insertion portion 144, which forms a pair with the insertion portion 141, has a tip portion 141a, an insertion portion side engagement edge 142, and a tip portion 144a that is linearly symmetrical with the notch portion 143, an insertion portion side engagement edge 145, a notch portion 146, and a notch portion facing surface 146a, and is formed on the other side of both ends of the free end side of the bottom outer flap 140.

The central recess 147 is a portion formed between the pair of insertion portions 141 and 144 and recessed in a concave shape relative to the insertion portions 141 and 144. In this embodiment, the central recess 147 is recessed in a rectangular shape in a plan view.

The line 148 is a linear portion that is formed to temporarily fold the bottom outer flap 140 when inserting the pair of insertion portions 141, 144 into the insertion openings 121, 131, to facilitate inserting the insertion portions 141, 144 into the insertion openings 121, 131. The line 148 is formed in the portion of the bottom outer flap 140 between the line 114a and the cutout portion 146.

The bottom outer flap 150, which forms a pair with the bottom outer flap 140, is formed with insertion portions 151, 154, which are linearly symmetrical with the insertion portions 141, 144, tip portions 141a, 144a, insertion portion side engagement edges 142, 145, notches 143, 146, central recess 147, and line 148, tip portions 151a, 154a, insertion portion side engagement edges 152, 155, notches 153, 156, notch portion facing surfaces 153a, 156a, central recess 157, and line 158.

The pair of inner lid flaps 161, 162, together with the pair of outer lid flaps 163, 164, constitute the lid 103 of the packaging box 100. In this case, the inner lid flap 161 and the inner lid flap 162 are formed to have the same shape, so the description will be mainly focused on the inner lid flap 161.

The lid inner flap 161 is a part that forms half of the lid 103 of the packaging box 100, and is formed in a rectangular shape in a plan view. In this case, the shape of the lid inner flap 161 is determined appropriately according to the shape of the packaging box 100. In this embodiment, the lid inner flap 161 is formed in the same outer peripheral shape as the bottom inner flap 120. The lid inner flap 162 that forms a pair with this lid inner flap 161 is disposed adjacent to the side wall 112 via the ruled line 112d.

The pair of outer lid flaps 163, 164, together with the pair of inner lid flaps 161, 162, constitute the lid 103 of the packaging box 100. In this case, the outer lid flap 163 and the outer lid flap 164 are formed to have the same shape, so the following description will mainly focus on the outer lid flap 163.

The lid outer flap 163 is a portion that covers a portion of each of the lid inner flaps 161, 162 that constitute the lid 103 of the packaging box 100, and is formed in a rectangular shape in a plan view. In this case, the shape of the lid outer flap 163 is appropriately determined according to the shape of the packaging box 100. In this embodiment, the lid outer flap 163 is formed in the same outer peripheral shape as the bottom outer flap 150. The lid outer flap 164 that forms a pair with this lid outer flap 163 is disposed adjacent to the end wall 115 via the line 115b.

(Operation of the Packaging Box 100)
Next, the operation of the packaging box 100 configured as described above will be described. First, a user of the packaging box 100 prepares a packaging box forming sheet body 105. Specifically, the user can use a known cutting device that cuts a plate-like corrugated cardboard sheet into any shape to form a pair of side walls 111, 112, a pair of end walls 114, 115, a pair of bottom inner flaps 120, 130, a pair of bottom outer flaps 140, 150, a pair of lid inner flaps 161, 162, and a pair of lid outer flaps 163, 164 on one cardboard sheet.

Next, the user assembles the packaging box forming sheet body 105 into the packaging box 100. Specifically, as shown in FIG. 7, the user folds the lines 111a, 111b, 112a, and 112b, and attaches the joining pieces 113 formed on the side walls 111 to the ends of the end walls 115 using adhesive (not shown) to form the packaging box forming sheet body 105 into a cylindrical shape. In this case, the user also attaches the parts of the joining pieces 113 that protrude toward the bottom outer flap 150 and the lid outer flap 164 to the bottom outer flap 150 and the lid outer flap 164, respectively.

Next, the user forms the bottom portion 101. In this case, the user may form the bottom portion 101 without forming the lid portion 103, but forming the bottom portion 101 after forming the lid portion 103 (see FIG. 1) can make the work of forming the bottom portion 101 easier. Therefore, in this embodiment, the lid portion 103 is formed before the work of forming the bottom portion 101.

Specifically, the user folds lines 111d and 112d to butt lid inner flap 161 and lid inner flap 162 together, and then folds lines 114b and 115b to place lid outer flap 163 and lid outer flap 164 opposite each other on lid inner flap 161 and lid inner flap 162. This allows the user to form lid 103. Note that when forming lid 103, the relationship between lid inner flaps 161 and 162 and lid outer flaps 163 and 164 can be reversed. That is, after folding lines 114b and 115b to place lid outer flap 163 and lid outer flap 164 opposite each other, fold lines 111d and 112d to place lid inner flap 161 and lid inner flap 162 opposite each other on lid outer flap 163 and lid outer flap 164.

Next, the user forms the bottom 101. Specifically, as shown in FIG. 8, the user folds the lines 111c and 112c, respectively, and butts the bottom inner flap 120 and the bottom inner flap 130 together to form a part of the bottom 101. Next, as shown in FIG. 9(A) and (B), the user folds the line 114a, respectively, and inserts the insertion portions 141 and 144 of the bottom outer flap 140 into the insertion opening 121 of the bottom inner flap 120 and the insertion opening 131 of the bottom inner flap 130, respectively. In this case, the user can easily insert the insertion portions 141 and 144 into the insertion openings 121 and 131, respectively, by folding the bottom outer flap 140 at the line 148.

The user also inserts the insertion portions 141, 144 from the connecting portions 123a, 133a of the insertion openings 121, 131, pushing down the opening flaps 123, 133 that close the insertion openings 121, 131 to open the insertion openings 121, 131. The user then inserts the insertion portions 141, 144 into the insertion openings 121, 131 until the insertion portion side engagement edges 142, 145 of the insertion portions 141, 144 face the opening side engagement edges 122, 132 of the insertion openings 121, 131, respectively. As a result, the bottom outer flap 140 is connected to the bottom inner flaps 120 and 130 without coming off because the insertion side engagement edges 142 and 145 are pressed against the opening side engagement edges 122 and 132, respectively, by the restoring force of the bent crease 114a.

Next, the user folds the crease 115a and inserts the insertion sections 151, 154 of the bottom outer flap 150 into the insertion opening 124 of the bottom inner flap 120 and the insertion opening 134 of the bottom inner flap 130, respectively. In this case, the worker inserts the insertion sections 151, 154 into the insertion openings 124, 134, respectively, in the same manner as the insertion section 141, 144 is inserted into the insertion openings 121, 131 described above. As a result, the bottom outer flap 150 is connected to the bottom inner flaps 120, 130 without coming off because the insertion section side engagement edges 152, 155 are pressed against the opening side engagement edges 125, 135, respectively, by the restoring force of the bent crease 115a. This allows the user to form the bottom 101 and complete the packaging box 100 (see Figures 1 and 2).

Next, the user can use the packaging box 100 as a container. Specifically, the user opens the lid portion 103 by opening the lid portion outer flaps 163, 164 upward with the bottom 101 side facing downward and the lid portion 103 facing upward, and then opening the lid portion inner flaps 161, 162 upward to open the lid portion 103. The user can then place an object to be contained in the packaging box 100 and close the lid portion inner flaps 161, 162 and the lid portion outer flaps 163, 164 again to form the lid portion 103. This allows the user to transport or store the packaging box 100 containing the object to be contained. In this case, the shape of the bottom 101 of the packaging box 100 is maintained by the insertion portion side engagement edges 142, 145 and the opening side engagement edges 122, 132 coming into close contact with each other, and the insertion portion side engagement edges 152, 155 coming into close contact with the opening side engagement edges 125, 135.

Next, the user can disassemble the packaging box 100. Specifically, the user can unfold the packaging box 100 and return it to the packaging box forming sheet body 105 by reversing the procedure used to assemble the packaging box 100 from the packaging box forming sheet body 105. In this case, the user can pull out the insertion parts 141, 144 from the insertion openings 121, 131, respectively, by disengaging the insertion part side engagement edges 142, 145 upward from the opening side engagement edges 122, 132, and separate the bottom outer flap 140 from the bottom inner flaps 120, 130, respectively.

The user can also pull the insertion sections 151, 154 out of the insertion openings 124, 134 by disengaging the insertion section side engagement edges 152, 155 upward from the opening side engagement edges 125, 135, respectively, and separate the bottom outer flap 150 from the bottom inner flaps 120, 130, respectively.

As can be understood from the above operation description, according to the above embodiment, the packaging box 100 has opening side engagement edges 122, 125, 132, 135 and insertion portion side engagement edges 142, 145, 152, 155 which are formed to extend at angles α and β of 45° respectively with respect to the grain direction L of the core which is perpendicular to the direction in which the waves of the core of the cardboard sheet are formed, in order to prevent the insertion portions 141, 144, 151, 154 from slipping out of the insertion openings 121, 124, 131, 134. Therefore, damage to each other can be suppressed even when the insertion portions 141, 144, 151, 154 and the insertion openings 121, 124, 131, 134 are pressed against each other with a strong force. As a result, the packaging box 100 can effectively prevent the insertion portions 141, 144, 151, and 154 of the bottom outer flaps 140 and 150, which are inserted into the insertion openings 121, 124, 131, and 134 formed in the bottom inner flaps 120 and 130, respectively, from falling out for a long period of time.

Furthermore, the present invention is not limited to the above-described embodiment, and various modifications are possible without departing from the purpose of the present invention. In the description of each modification, the same parts as those in the above-described embodiment are given the same reference numerals.

For example, in the above embodiment, the opening side engagement edges 122, 125, 132, 135 and the insertion side engagement edges 142, 145, 152, 155 are formed to extend at angles α and β of 45° with respect to the grain direction L of the core of the cardboard sheet that constitutes the packaging box 100. However, the angles α and β of the opening side engagement edges 122, 125, 132, 135 and the insertion side engagement edges 142, 145, 152, 155 may be formed to extend at angles of at least 30° and no more than 50° with respect to the grain direction L of the core of the cardboard sheet.

In this case, the opening side engaging edges 122, 125, 132, 135 and the insertion side engaging edges 142, 145, 152, 155 are preferably formed to extend within angles α and β of 45°±5° relative to the grain direction of the core of the cardboard sheet. In these cases, the angle α of the opening side engaging edges 122, 125, 132, 135 and the angle β of the insertion side engaging edges 142, 145, 152, 155 may be formed at different inclination angles, but it is preferable that they are formed parallel to each other at the same inclination angle.

In addition, in the above embodiment, the opening side engagement edges 122, 125, 132, 135 are formed to extend at an angle so that the end on the outer periphery side of the packaging box 100 is located forward of the inner end of the packaging box 100 in the insertion direction of the insertion parts 141, 144, 151, 154 into the insertion openings 121, 124, 131, 134. This allows the packaging box forming sheet body 105 to be inserted in a sufficiently inclined position (lying down position) from a position spaced apart from the insertion parts 141, 144, 151, 154 relative to the insertion openings 121, 124, 131, 134, facilitating the insertion work.

However, as shown in FIG. 10, the opening side engagement edges 122, 132 can also be formed to extend at an incline so that the end on the outer periphery side of the packaging box 100 is located further rearward in the insertion direction of the insertion sections 141, 144 into the insertion openings 121, 131 than the inner end of the packaging box 100. In this case, the insertion section side engagement edges 142, 145 are formed to extend at an incline so that the end on the outer periphery side of the packaging box 100 is located further rearward in the insertion direction of the insertion sections 141, 144 than the inner end of the packaging box 100.

The opening side engaging edges 125, 135 and the insertion side engaging edges 152, 155 can be configured similarly to the opening side engaging edges 122, 132 and the insertion side engaging edges 142, 145 shown in Figure 10. Note that in Figure 10, the side walls 112, end walls 115, bottom inner flap 130, bottom outer flap 150, lid inner flap 162, and lid outer flap 164 are not shown.

In the above embodiment, one end of each of the opening side engaging edges 122, 125, 132, 135 is directly connected to the front edge 121a, 124a, 131a, 134a, and the other end is directly connected to the connecting portion 123a, 126a, 133a, 136a. This allows the packaging box forming sheet body 105 to have a compact and simple insertion opening 121, 124, 131, 134. However, it is also possible to configure one end of each of the opening side engaging edges 122, 125, 132, 135 so that it is not directly connected to the front edge 121a, 124a, 131a, 134a, and it is also possible to configure the other end so that it is not directly connected to the connecting portion 123a, 126a, 133a, 136a.

In addition, in the above embodiment, the insertion openings 121, 124, 131, and 134 are configured with opening flaps 123, 126, 133, and 136, respectively. However, the insertion openings 121, 124, 131, and 134 can also be configured to be always open by omitting the opening flaps 123, 126, 133, and 136.

In the above embodiment, the insertion portion side engaging edges 142, 145, 152, 155 are formed as part of the inner wall surface of the cutout portions 143, 146, 153, 156. This allows the insertion portion side engaging edges 142, 145, 152, 155 of the packaging box forming sheet body 105 to be easily positioned opposite the opening side engaging edges 122, 125, 132, 135, and the insertion portions 141, 144, 151, 154 can be easily lifted up and removed from the insertion openings 121, 124, 131, 134 by placing fingers on the cutout portions 143, 146, 153, 156.

However, as shown in Figures 11(A) and (B), the insertion side engagement edges 142, 145 can be formed by linear cuts extending inward from the outer peripheral surface of the bottom outer flap 140, and can also be configured to be covered by the portion facing this cut. In this way, when the insertion side engagement edges 142, 145 are in contact with the opening side engagement edges 122, 132, the contact portion is covered by the bottom outer flap 140 and prevented from being exposed to the outside, so that the insertion side engagement edges 142, 145 can be effectively prevented from coming off the opening side engagement edges 122, 132.

In addition, the packaging box forming sheet body 105 prevents the contact surface between the insertion part side engaging edges 142, 145 and the opening side engaging edges 122, 132 from being exposed, eliminating unevenness around the insertion part side engaging edges 142, 145 and preventing objects facing the bottom inner flap 120 and bottom outer flap 140 from getting caught. The insertion part side engaging edges 152, 155 and the opening side engaging edges 125, 135 can also be configured in the same way as the insertion part side engaging edges 142, 145 and the opening side engaging edges 122, 132 shown in Figures 11 (A) and (B), respectively.

In these cases, the leading ends of the insertion part side engaging edges 142, 145 formed by the cuts may be provided with relief portions 142a, 145a that extend in a curved line. In this way, even if the insertion part side engaging edges 142, 145 come into contact with the opening side engaging edges 122, 132 and the cuts that constitute the insertion part side engaging edges 142, 145 are opened, the relief portions 142a, 145a can prevent the leading ends of the cuts from cracking and splitting . The insertion part side engaging edges 152, 155 can also be formed as relief portions similar to the relief portions 142a, 145a of the insertion part side engaging edges 142, 145 shown in Figures 11(A) and 11(B), respectively. Also, Figures 11(A) and 11(B) show only the bottom outer flap 140.

In the above embodiment, the packaging box forming sheet body 105 has the insertion openings 121, 124, 131, 134 formed in the bottom inner flaps 120, 130, respectively, and the insertion sections 141, 144, 151, 154 formed in the bottom outer flaps 140, 150, respectively. That is, the bottom inner flaps 120, 130 correspond to the inner flaps according to the present invention, and the bottom outer flaps 140, 150 correspond to the outer flaps according to the present invention. However, the packaging box forming sheet body 105 can also have the insertion openings 121, 124, 131, 134 and the insertion sections 141, 144, 151, 154 formed in the outer peripheral wall 102 and the lid section 103 of the packaging box 100, respectively.

In the above embodiment, the packaging box forming sheet body 105 is made of a plate-shaped cardboard sheet. However, the packaging box forming sheet body 105 can be made of a plate-shaped body that can be bent by hand. Therefore, the packaging box forming sheet body 105 can also be made of a paper material other than cardboard sheet (e.g., cardboard) or a resin material (e.g., plastic cardboard).

C: circle showing grain direction of cardboard sheet; L: grain direction of core; α: angle of engagement edge on opening side; β: angle of engagement edge on insertion side;
100: packaging box, 101: bottom, 102: outer wall, 103: lid,
105...packaging box forming sheet body 111...side wall, 111a to 111d...ruled lines,
112...side wall, 112a to 112d...ruled lines,
113... Joint piece,
114... end wall, 114a, 114b... creases,
115... end wall, 115a, 115b... creases,
120: bottom inner flap; 121, 124: insertion opening; 121a, 124a: front end edge; 121b, 124b: side escape portion; 122, 125: opening side engagement edge; 123, 126: opening flap; 123a, 126a: connecting portion;
130: bottom inner flap; 131, 134: insertion opening; 131a, 134a: front end edge; 131b, 134b: side escape portion; 132, 135: opening side engagement edge; 133, 136: opening flap; 133a, 136a: connecting portion;
140: bottom outer flap; 141, 144: insertion portion; 141a, 144a: tip portion; 142, 145: insertion portion side engagement edge; 142a, 145a: escape portion; 143, 146: notch portion; 143a, 146a: notch portion facing surface; 147: central recess; 148: ruled line;
150: bottom outer flap; 151, 154: insertion portion; 151a, 154a: tip portion; 152, 155: insertion portion side engagement edge; 153, 156: notch portion; 153a, 156a: notch portion facing surface; 157: central recess; 158: ruled line;
161, 162...Inner flap of lid portion,
163, 164...Outer flaps of lid.

Claims (6)

A packaging box made of a corrugated cardboard sheet,
a cylindrical body portion having a pair of side walls and a pair of end walls;
a blocking surface portion that blocks at least one opening of the body portion,
The blocking surface portion is
A pair of inner flaps respectively connected to the edge portions of the pair of side walls;
a pair of outer flaps respectively connected to the edge portions of the pair of end walls and respectively overlapping the outer surfaces of the pair of inner flaps;
The pair of outer flaps each have a pair of insertion portions,
The pair of inner flaps each have a pair of insertion openings into which the insertion portions are respectively inserted,
The pair of insertion openings are:
a part of the inner periphery of the insertion opening, and an opening side engagement edge at an end edge on the side in the direction of removal of the insertion portion inserted into the insertion opening;
The pair of insertion portions are
a part of the outer periphery of the insertion portion has an insertion portion side engaging edge that comes into contact with the opening side engaging edge when the insertion portion is inserted into the insertion opening,
The opening side engagement edge and the insertion portion side engagement edge are
Each extends at an angle of 30° or more and 50° or less with respect to the grain direction of the core of the cardboard sheet,
The insertion opening is
a front end edge formed by extending in a direction perpendicular to the insertion direction of the insertion portion at the inner circumferential edge of the insertion portion;
an opening flap provided within the insertion opening and connected to the inner flap, the opening flap being tiltable inward and outward of the insertion opening with a portion connected to the inner flap as a fulcrum;
The opening side engagement edge is
A packaging box, characterized in that the end of the portion of the inner flap where the opening flap is connected is directly connected to the front end edge.
The packaging box according to claim 1,
The opening side engagement edge and the insertion portion side engagement edge are
A packaging box characterized in that the cores are formed so that each extends at an angle range of 45°±5° relative to the grain direction of the core. The packaging box according to claim 1 or 2,
The opening side engagement edge is
A packaging box characterized in that the end portion on the outer periphery of the packaging box extends at an angle so as to be positioned further forward in the insertion direction of the insertion portion into the insertion opening than the inner end portion of the packaging box. The packaging box according to any one of claims 1 to 3 ,
The outer flap is
A part of the outer periphery of the plate has a recessed cutout portion.
The insertion portion side engagement edge is
A packaging box characterized in that it is formed in an exposed state within the cutout portion. The packaging box according to any one of claims 1 to 3 ,
The insertion portion side engagement edge is
A packaging box characterized in that the outer flap is formed by a linear cut extending inward from the outer peripheral edge of the outer flap and is covered by a portion facing this cut. The packaging box according to claim 5,
The incision is
The packaging box is characterized in that the inner tip portion of the outer flap is formed with a relief portion that extends by bending along a curve.

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