JP6476032B2 - Packaging box - Google Patents

Description

  The present invention relates to a packaging box used for packaging products.

  Conventionally, packaging boxes made of cardboard, cardboard, or the like have been used for packaging products in stores, and Patent Document 1 discloses a packaging box formed by folding a sheet material. The packaging box of such a form is widely used because it can be folded and stored in a non-bulky state until just before use, and can be easily formed into a box shape at the time of packaging.

  The packaging box disclosed in Patent Document 1 includes a rectangular tube-shaped body portion including a front plate, a rear plate, and two side plates, a bottom plate that closes a lower opening of the body portion, and two sheets that close an upper opening. The two cover plates are connected to each other by a folding plate connected to the upper end of the side plate. The folding plate includes a folding plate having an isosceles right triangle with the upper end of the side plate as a base, and a pair of overlapping plates connected to the side end of the lid plate and connected to each other via a diagonal line. When packaging the product, close the lower opening of the body with the bottom plate, then store the product and close the lid plate. At this time, fold the folding plate along the diagonal line, Are folded and folded from the upper end of the side plate, and the tip of the triangle is inserted into a notch provided in the side plate and fixed. Thereby, the cover plate is fixed in a state of closing the upper opening of the trunk portion.

Japanese Utility Model Publication No. 1-76409

  In the packaging box disclosed in Patent Document 1, the folding plate that is bent in a diagonal line and formed into a triangular shape is easily lifted and protrudes in the horizontal direction simply by folding from the upper end of the side plate and pointing the tip downward. And the cover plate may open. Therefore, it is necessary to insert the triangle tip of the folding plate into the notch and fix it as described above, or to fix the triangle tip of the folding plate to the front plate and the rear plate with a tape or a seal. It was complicated. Further, even when the triangular tip of the folding plate is inserted into the notch, there is a possibility that the leading plate may come off from the notch and the folding plate may be lifted by the force with which the folding plate is lifted. In addition, when a tape, a seal, or the like is applied, there is a problem that it takes time and effort to peel off the tape or the seal at the time of opening.

  An object of the present invention is to provide a packaging box that can be easily packaged and opened and that is difficult to open.

The present invention is formed by bending a sheet material, and includes two side wall plates and two end wall plates that form a rectangular tube-shaped body, a bottom plate that closes a lower opening of the body, and the two Two lid plates respectively connected to the upper ends of the side wall plates, and two connecting plates connected to the side ends of the two lid plates and the upper ends of the end wall plates,
The connecting plate is composed of a receiving portion connected to the upper end of the end wall plate and two overlapping portions connected to the side ends of the lid plate,
The lid plate is folded inward at the lower end to close the upper opening of the body portion, and at the same time, the overlapping portion of the connecting plate is folded inward at the boundary with the receiving portion, and the receiving portion is folded outward at the lower end. At the same time, it is a packaging box that folds down the connecting plate by bending the overlapping portion at the side end,
The boundary between the receiving portion and the overlapping portion, Ri angle formed der 47 ° or less than the 45 ° of the lower end of the receiving portion,
When the overlapping portion is folded at the boundary with the receiving portion, the two overlapping portions of the connecting plate each have a region that partially overlaps,
In the overlapping region of the overlapping portion, a protruding piece that is cut in a substantially U shape from a side end of the lid plate and protrudes from the side end, and a protruding side edge of the protruding piece is a part of the opening end. And a cutout is formed,
When two sheets of the overlapped portion of the connecting plate are overlapped with each other, the projecting pieces formed in each of the said cutouts and said overlap with Rukoto each other.

Moreover, in this invention, the following structure is included as a preferable aspect.
When the connecting plate is folded downward, the receiving portion warps in a curved shape so that the boundary between the receiving portion and the overlapping portion is stressed in a direction approaching the end wall plate with the upper end of the end wall plate as a fulcrum. Receive.
An angle formed by a boundary between the receiving portion and the overlapping portion and a lower end of the receiving portion is 46 ° or greater and 47 ° or less.
The receiving portion has a trapezoidal shape with a lower end at the bottom .
1mm~3mm in the direction along the side edge of the front Symbol cover plate, the distance from the lower end of the receiving portion to the center of the cut-out and the projecting piece, than half the length of the upper end of the end wall plate short.
The substantially U-shaped cutting line forming the protruding piece extends from the connecting plate side to the lid plate side so that both ends thereof are located in the lid plate beyond the side edge of the lid plate. Is formed.

  According to the present invention, since the folded connection plate naturally faces downward by shifting the boundary between the receiving portion and the overlapping portion of the connection plate from the conventional position, the connection plate is fixed to the end wall plate. Even if it does not do, it becomes difficult to lift the connecting plate. Furthermore, a connection piece can be hold | maintained in the state along the end wall board by providing a protrusion piece and a cut-out in the overlap part of a connection board, and fixing the overlap parts which mutually overlap. Therefore, according to the present invention, it is possible to provide a packaging box in which the lid body is not easily opened by a simple packaging operation and the opening operation is easy.

It is an expanded view of one Embodiment of the packaging box of this invention. It is a perspective view which shows the state which shape | molded the packaging box of FIG. It is the figure which looked at the packaging box of FIG. 2 from the downward direction. FIG. 3 is a top view of the periphery of a connecting plate in a state in which a cover plate of the packaging box of FIG. It is a perspective view which shows the connection board periphery of the state which folded down the connection board of the packaging box of FIG. It is the elements on larger scale of the connection board of the expanded view of FIG. FIG. 3 is a top view of the periphery of the connecting plate in a state in which the receiving portion and the overlapping portion in the connecting plate of the packaging box of FIG. In embodiment which shifted the protrusion piece provided in the two overlap part of the connection board, and the position of a cutout, it is a top view of the connection board periphery of the state which closed the cover board. It is the elements on larger scale of the cover board of the expanded view of FIG. It is a top view of the state which closed the cover plate of the packaging box of FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings, but the present invention is not limited to the following embodiments. In the drawings referred to below, the same reference numerals denote the same components.

  FIG. 1 is a developed view of a preferred embodiment of the packaging box of the present invention, and FIG. 2 is a perspective view showing a state in which the packaging box of FIG. The broken line and the alternate long and short dash line in the figure are fold lines, the broken line indicates a mountain fold line, and the alternate long and short dash line indicates a valley fold line.

  The packaging box of the present invention is basically formed by bending a sheet material. Examples of the sheet material used in the present invention include conventionally used paperboard, cardboard, cardboard, and plastic sheet.

  The packaging box of the present invention includes two side wall plates 10 and 10, two end wall plates 20 and 20 that form a rectangular tube-shaped body 100, and a bottom plate 30 that closes a lower opening of the body 100, Two cover plates 40, 40 connected to the upper end 11 of the side wall plate 10, and two connection plates 50, 50 connected to the side end 41 of the cover plate 40 and the upper end 21 of the end wall plate 20. Have. The connecting plates 50 and 50 are connected by being sandwiched between the side ends 41 and 41 of the two cover plates 40, respectively.

  In the present invention, first, the rectangular tubular body 100 is formed by bending the boundary between the side wall plate 10 and the end wall plate 20 of the sheet material of FIG. In this example, since the sticking plate 73 is connected to one side end of the one end wall plate 20 on the left side of the paper surface, the sticking plate 73 is bonded and fixed to the side wall plate 10 on the right side of the paper surface with an adhesive. To do. In addition, a sticking plate 74 is connected to one side end of the one connecting plate 50 on the left side of the paper surface, and the sticking plate 74 is bonded and fixed to the one lid plate 40 on the right side of the paper surface with an adhesive. .

  Next, the bottom plate 30 is bent 90 ° from the lower end 12 of the one side wall plate 10 to which the bottom plate 30 is connected to close the lower opening of the trunk portion 100. In this example, since the reinforcing plate 32 is connected to the end 31 of the bottom plate 30 opposite to the end 12 connected to the side wall plate 10, the reinforcing plate 32 is bent 90 ° at the end 31. The other side wall plate 10 is placed along the inside. In this example, a reinforcing plate 62 is connected to the lower end 22 of one end wall plate 20, and an adhesive plate 72 is connected to the reinforcing plate 62 via a folding line. By adhering 72 to the bottom plate 30 with an adhesive, the bottom plate 30 is connected to the end wall plate 20 via the reinforcing plate 62 and reinforced.

  Further, in this example, a reinforcing plate 60 is connected to the lower end 12 of the other side wall plate 10, and the reinforcing plate 60 is bent at 90 ° at the lower end 12 to partially cover the outside of the bottom plate 30. The face plate 30 is reinforced. In this example, the reinforcing plate 61 is connected to the lower end 22 of the other end wall plate 20, and the reinforcing plate 61 is connected to the reinforcing plate 61 via a folding line. The reinforcing plate 60 is connected to the other end wall plate 20 via the reinforcing plate 61 by adhering to the adhesive plate 60 with an adhesive, and the reinforcing plate 60 itself is reinforced.

  As described above, the rectangular tubular body 100 is formed and the lower opening of the body 100 is closed, so that the form shown in FIG. 2 can be obtained. FIG. 3 is a view as seen from below in this state, and the bottom portion with high strength is formed by inserting the lower right corner of the reinforcing plate 60 into the gap between the bottom plate 30 and the reinforcing plate 62. .

  In the present invention, it can be folded into a flat plate shape from the state of FIG. That is, one end wall plate 20 on the left side of FIG. 1 is bent at the boundary between the reinforcing plate 61 and the sticking plate 71, the boundary between the reinforcing plate 62 and the sticking plate 72, and the folding line in the bottom plate 30. By folding one side wall plate 10 and the other end wall plate 20 on the right side of the paper on the other side wall plate 10 so as to overlap each other and closing the opening of the body portion 100, can do.

  When the product is stored in the body 100 from the state of FIG. 2 and the cover plates 40 and 40 are closed, the cover plate 40 is bent 90 ° inward at the lower end, that is, the upper end 11 of the side wall plate 10. At this time, the connecting plates 50 and 50 are folded inward at the boundary 53 with the receiving portion 51 and overlapped with each other, and the receiving portion 51 is bent 90 ° outward at the lower end, that is, the upper end 21 of the end wall plate 20. In this state, the connecting plate 50 projects in the horizontal direction as shown in FIG.

  Further, the receiving portion 51 is further bent 90 ° at the lower end 21, and the overlapping portion 52 is bent 90 ° at the side end, that is, the side end 41 of the lid plate 40, thereby folding the connecting plate 50 downward. This state is shown in FIG.

  Here, in the present invention, the connecting plate 50 folded downward is difficult to lift upward. This will be described with reference to FIGS.

  In the present invention, the angle θ1 formed by the boundary 53 between the receiving portion 51 and the overlapping portion 52 of the connecting plate 50 and the lower end 21 of the receiving portion 51 is more than 45 ° and not more than 47 °. Therefore, the angle θ2 formed by the boundary 53 between the receiving portion 51 and the overlapping portion 52 of the connecting plate 50 and the side end 41 of the overlapping portion 52 is 43 ° or more and less than 45 °.

  Conventionally, the connecting plate 50 has been bent at the boundary of θ1 = θ2 = 45 ° so that the lower end 21 of the receiving portion 51 and the side end 41 of the overlapping portion 52 coincide and overlap when bent. In the present invention, by making θ1 slightly larger than θ2, an action that causes the connecting plate 50 to face downward can be obtained. When θ1> θ2, the distance L1 from the boundary 53 to the lower end 21 of the receiving portion 51 is slightly longer than the distance L2 from the boundary 53 to the side end 41 of the overlapping portion 52 at an arbitrary position of the boundary 53. Therefore, when the receiving portion 51 and the overlapping portion 52 are separated at the boundary 53 and are overlapped so that the side end 41 of the overlapping portion 52 and the lower end 21 of the receiving portion 51 coincide with each other, as shown in FIG. The position 53 is displaced.

  In the present invention, when the connecting plate 50 is folded down, the center of the receiving portion 51 is separated from the overlapped portion 52 due to such a deviation, that is, curved in a convex shape toward the end wall plate 20. Since the restoring force acts on the receiving portion 51 in a direction to eliminate the bending, the boundary 53 between the receiving portion 51 and the overlapping portion 52 is applied to the end wall plate 20 with the upper end 21 of the end wall plate 20 as a fulcrum by the restoring force. It receives stress in the approaching direction. Therefore, according to the present invention, even if the connecting plate 50 folded downward is not fixed to the end wall plate 20, the downwardly facing state is maintained, the tip is inserted into the notch, and a tape or a seal is applied. There is no need to fix it.

  In addition, the boundary 53 between the overlapped portion 52 and the receiving portion 51 and the lower end 21 of the receiving portion 51 are preliminarily creased or can be easily bent by a half cut or a perforation described later. Since the side end 41 of the overlapping portion 52 is already bent at 90 ° and has a crease at the time of molding, the overlapping portion 52 naturally overlaps with the receiving portion 51 when the lid plates 40 and 40 are closed, and is connected. The plate 50 is bent downward, and the packaging operation itself is facilitated.

  In the present invention, the above action is obtained when θ1 exceeds 45 °, and it is preferably 46 ° or more in order to reliably obtain such an action. Further, if θ1 exceeds 47 °, the difference from θ2 becomes too large, and conversely, the connecting plate 50 tends to be difficult to be folded down, so θ1 is 47 ° or less.

  When the state in which the connecting plate 50 is folded downward is maintained, the lid plate 40 is pulled between the both side ends 41 and 41 because the side end 41 is connected to the connecting plate 50, and is difficult to open. Become. Further, since the folded connection plate 50 is not fixed, the lid plate 40 can be easily opened simply by pulling the lower tip, that is, the upper end of the overlapping portion 52 in the development view of FIG. be able to.

  In addition, in this example, although the receiving part 51 is made into the trapezoid shape which makes the lower end 21 the lower base, a shape is not specifically limited in the range in which the overlapping parts 52 and 52 are not connected mutually. For example, it is good also as an isosceles triangle which makes the intersection on the extension line of the boundaries 53 and 53 a vertex, and makes the lower end 21 of the receiving part 51 a base.

  In the present invention, as described above, by adjusting the angle formed between the boundary 53 between the receiving portion 51 and the overlapping portion 52 and the lower end 21 of the receiving portion 51, the folded connecting plate 50 has an effect of facing downward. In addition, by providing the overlapping portion 52 with the protruding piece 52a and the cutout 52b, it is possible to reliably suppress the floating of the folded connection plate 50. This will be described with reference to FIGS.

  In the packaging box of this example, the length W2 of the side end 41 of the overlap portion 52 is longer than ½ of the length W1 of the upper end 21 of the end wall plate 20, and the overlap portion 52 is bent at the boundary 53 to receive. When overlapped with the portion 51, the two overlapping portions 52, 52 of the connecting plate 50 have regions that overlap each other. In this example, a protruding piece 52a and a cutout 52b are provided in this overlapping region. The protruding piece 52a is formed by being cut into a substantially U-shape from the side end 41 of the overlapping portion 52. In a preferred form in this example, the protruding piece 52a extends beyond the side end 41 of the cover plate 40. 40 is formed from within. The cutout 52b is formed adjacent to the protruding side of the protruding piece 52a with the protruding side edge of the protruding piece 52a as a part of the opening end. The protruding piece 52a and the cutout 52b are formed to face the two overlapping portions 52 and 52, respectively.

  In this example, when the overlapping portion 52 is folded at the boundary 53 and overlapped with the receiving portion 51, when one overlapping portion 52 is overlapped on the other overlapping portion 52, as shown in FIG. The protruding piece 52a and the other protruding piece 52a, and one cutout 52b and the other cutout 52b overlap each other. In this state, when the receiving portion 51 is bent at the lower end 21 and the overlapping portion 52 is bent at the side end 41 and the connecting plate 50 is folded down, the protruding piece 52a continues to the lid plate 40 as shown in FIG. Then, the overlapping portion 52 other than the protruding piece 52a is folded downward in a state protruding in the horizontal direction. At this time, the other projecting piece 52a located below protrudes into the opening opened by the other projecting piece 52a located above and is fitted into the opening, and the two overlapping portions 52, 52 are mutually connected. At the same time, the connecting plate 50 is unlikely to rise upward due to friction between the other protruding piece 52a and the opening end of the opening into which the protruding piece 52a is fitted.

  In this example, the length t1 in the protruding direction of the protruding piece 52a is 3 mm to 5 mm. If it is less than 3 mm, the fitting is easily disengaged, and if it exceeds 5 mm, the effect does not change, and the protruding piece 52 a protruding in the reverse direction may interfere. In addition, when the protruding piece 52a is formed from the cover plate 40 beyond the side end 41 of the cover plate 40 as in this example, the length t2 on the cover plate 40 side is formed to be 1 mm to 2 mm. . In this case, t1-t2 = t3 is adjusted to be 2 mm or more. When the protruding piece 52a is formed from the lid plate 40 beyond the side end 41 of the lid plate 40 as in this example, the cut end portion (the U-shaped end portion) of the protruding piece 52a is inside the lid plate 40. Since the protruding portion 52a is bent by the overlapping portion 52 when the overlap portion 52 is bent at the side end 41, the cut end portion is cut off. There is no risk of inconvenience.

  Moreover, as for the length t4 of the direction along the side end 41 of the protrusion piece 52a, 10 mm-40 mm are preferable. If t4 is too short, the strength is inferior, and if it is too long, the region left in the overlapped portion 52 becomes narrow, and the strength of the overlapped portion 52 decreases.

  Further, the cutout 52b is provided so that the protruding piece 52a positioned below easily protrudes into the opening through which the protruding piece 52a positioned above is removed, but the length t5 in the direction along the side end 41 is the protruding piece. The length t4 is preferably the same as the length t4 of 52a, or about 0.5 mm to 1 mm spreading across the protruding piece 52a. The length t6 in the direction perpendicular to the side end 41 of the cutout 52b is 5 to 30 mm.

  In this example, in the direction along the side edge 41 of the cover plate 40, the distance W3 from the lower end 21 of the receiving portion 51 to the center of the protruding piece 52a is ½ of the length W1 of the lower end 21 of the receiving portion 51. If they are equal, the protruding pieces 52a and 52a and the cutouts 52b and 52b of the two overlapping portions 52 and 52 overlap with each other when they are bent at the boundary 53 with the receiving portion 51. In this example, the protruding pieces 52a and 52a and the cutouts 52b and 52b of the two overlapping portions 52 and 52 may be shifted.

  Specifically, in the direction along the side edge 41 of the cover plate 40, the distance W3 from the lower end 21 of the receiving portion 51 to the center of the protruding piece 52a is 1 / W of the length W1 of the upper end 21 of the end wall plate 20. The positions of the protruding piece 52a and the cutout 52b are adjusted so as to be 1 to 3 mm shorter than 2. In this case, when the overlapping portion 52 is bent at the boundary 53 with the receiving portion 51, as shown in FIG. 8, the protruding pieces 52a, 52a and the cutouts 52b, 52b of the two overlapping portions 52, 52 are In the direction along the side edge 41 of the lid plate 40, the displacement occurs. Therefore, by pushing the boundaries 53 and 53 between the receiving portion 51 and the overlapping portion 52 in the direction approaching each other (the direction indicated by the arrow A in FIG. 8), the lower protruding piece 52a is changed to the upper protruding piece 52a. The connecting plate 50 is folded down in a completely overlapped state, and the lower protruding piece 52a is fitted into the opening from which the upper protruding piece 52a has been removed to obtain the state shown in FIG.

  In this case, in the state of FIG. 5, the overlapping portions 52 and 52 are stressed in a direction away from each other, and the lower protruding piece 52a is pressed by the opening end of the opening through which the upper protruding piece 52a is removed, and from the opening. It becomes difficult to come off. Further, by pushing the boundaries 53, 53 between the receiving portion 51 and the overlapping portion 52 in the direction approaching each other, the receiving portion 51 is more curved, so that the action of directing the connecting plate 50 downward is provided as described above. Become stronger. Therefore, in this example, the state in which the folded connection plate 50 faces downward is better maintained, and there is no possibility that the cover plate 40 opens.

  As described above, in this example, the protruding portion 52a and the cutout 52b are provided in the overlapping portion 52 to fix the two overlapping portions 52 and 52 to each other, and the positions of the protruding piece 52a and the cutout 52b are two. By being shifted by the overlapping portions 52, 52, the state in which the folded connecting plate 50 faces downward is favorably maintained. At the time of opening, the cover plate 40 can be easily opened by simply pulling the tip of the folded connection plate 5 facing downward with a finger and lifting it upward, so that the fitted protruding piece 52a can be easily removed. be able to.

  In the present invention, as described above, the state where the lid plate 40 is not easily opened is maintained, but the minimum width W4 of the lid plate 40 shown in FIG. 9 is set to the upper end 21 of the end wall plate 20 shown in FIG. When the cover plate 40 is closed, the pair of cover plates 40 and 40 are overlapped with each other when the cover plate 40 is closed by making it longer than ½ of the length W1, thereby preventing the entry of foreign matter from the outside. it can. Further, when the lower end of the cover plate 40, that is, the upper end 11 of the side wall plate 10 is long, even if the pair of cover plates 40 and 40 overlap each other, the upper end of the lower end 11 of the cover plate 40 is at the center in the length direction. The lid plate 40 floats and a gap is easily formed between the lid plate 40 and the lower lid plate 40. Therefore, as shown in FIG. 9, when the projection 42 a is provided at the center of the upper end 43 of the lid plate 40, the notch 42 b is provided at a position corresponding to the projection 42 a, and the lid plate 40 is closed, As shown in FIG. 10, it is preferable that the protruding portion 42a of the cover plate 40 positioned above is inserted and fixed to the cut portion 42b of the cover plate 40 positioned below.

  As shown in FIG. 1, in the present invention, the pair of connecting plates 50 and 50 have the same configuration and are symmetric in shape. Further, the pair of cover plates 40, 40 has the same configuration and a symmetrical shape. Thereby, it can package similarly even if any of the side wall board 10 and 10 is foreground.

  In the packaging box of the present invention, in order to facilitate the folding at the valley fold line and the mountain fold line shown in the development view of FIG. You may take measures.

  10: side wall plate, 11: upper end of side wall plate, lower end of lid plate, 12: lower end of side wall plate, 20: end wall plate, 21: upper end of end wall plate, lower end of receiving portion, 22: lower end of end wall plate , 30: bottom plate, 31: edge of the bottom plate, 32: reinforcing plate, 40: lid plate, 41: side edge of the lid plate, side edge of the overlapping portion, 42a: protruding portion of the lid plate, 42b: notch, 43: upper end of cover plate, 50: connecting plate, 51: receiving portion, 52: overlapping portion, 52a: protruding piece, 52b: cutout, 53: boundary between receiving portion and overlapping portion, 60, 61, 62: reinforcing plate , 71, 72, 73, 74: sticking plate, 100: trunk

Claims (6)

Two side wall plates and two end wall plates that are formed by bending a sheet material to form a rectangular tube-shaped body, a bottom plate that closes a lower opening of the body, and the two side wall plates Two lid plates respectively connected to the upper ends of the two lid plates, and two connecting plates connected to the side ends of the two lid plates and the upper ends of the end wall plates,
The connecting plate is composed of a receiving portion connected to the upper end of the end wall plate and two overlapping portions connected to the side ends of the lid plate,
The lid plate is folded inward at the lower end to close the upper opening of the body portion, and at the same time, the overlapping portion of the connecting plate is folded inward at the boundary with the receiving portion, and the receiving portion is folded outward at the lower end. At the same time, it is a packaging box that folds down the connecting plate by bending the overlapping portion at the side end,
The boundary between the receiving portion and the overlapping portion, Ri angle formed der 47 ° or less than the 45 ° of the lower end of the receiving portion,
When the overlapping portion is folded at the boundary with the receiving portion, the two overlapping portions of the connecting plate each have a region that partially overlaps,
In the overlapping region of the overlapping portion, a protruding piece that is cut in a substantially U shape from a side end of the lid plate and protrudes from the side end, and a protruding side edge of the protruding piece is a part of the opening end. And a cutout is formed,
Two when the overlapping portions are overlapped with each other, the packaging box in which the projecting piece formed respectively with the cut-out is characterized by heavy for Rukoto each other of said connecting plate.   When the connecting plate is folded downward, the receiving portion warps in a curved shape so that the boundary between the receiving portion and the overlapping portion is stressed in a direction approaching the end wall plate with the upper end of the end wall plate as a fulcrum. The packaging box according to claim 1, wherein the packaging box is received.   The packaging box according to claim 1 or 2, wherein an angle formed between a boundary between the receiving portion and the overlapping portion and a lower end of the receiving portion is 46 ° or more and 47 ° or less.   The packaging box according to any one of claims 1 to 3, wherein the receiving portion has a trapezoidal shape with a lower end as a bottom. In the direction along the side edge of the lid plate, the distance from the lower end of the receiving portion to the center of the protruding piece and the cutout is 1 mm to 3 mm shorter than ½ of the length of the upper end of the end wall plate. The packaging box according to any one of claims 1 to 4, wherein the packaging box is provided. The substantially U-shaped cutting line forming the protruding piece extends from the connecting plate side to the lid plate side so that both ends thereof are located in the lid plate beyond the side edge of the lid plate. packaging box according to any one of claims 1 to 5, characterized in that it is formed by.

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