Packaging box

Abstract

To provide a packaging box capable of suppressing outward swelling of a bottom surface and a top surface.SOLUTION: A packaging box comprises a square cylindrical trunk part, a bottom surface, and a top surface. The trunk part is composed of first to fourth trunk pieces. The bottom surface and the top surface are each constituted by first to fourth flaps. The first to fourth flaps are connected to the first to fourth trunk pieces through folds, respectively. The first flap and the third flap are overlapped from the outside relative to the second flap and the fourth flap. The first flap and the third flap respectively comprise a first thin wall part and a third thin wall part on a side opposite to the folds that are thinner than sides on the folds. The second flap and the fourth flap comprise a second thin wall part and a fourth thin wall part, respectively, on the sides of the folds.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a packing box.

Background Art

[0002] Conventionally, packing boxes have been used to package articles. A packing box is disclosed in Patent Document 1. The packing box includes a rectangular tube-shaped body, a bottom surface, and a top surface. The body is composed of four body pieces. To each of the four body pieces, a flap is connected via a fold line. The flaps are provided below and above the body pieces, respectively. When the packing box is assembled, the four lower flaps form the bottom surface. Also, the four upper flaps form the top surface.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Of the four flaps on the bottom surface or the top surface, let two opposing flaps be Flaps A and B. Let the other two flaps be Flaps C and D. When forming the bottom surface or the top surface of the packing box, first, fold Flaps A and B inward. Next, fold Flaps C and D inward. At this time, Flaps C and D overlap Flaps A and B from the outside. The fold line for folding Flaps A and B and the fold line for folding Flaps C and D are in the same plane.

[0005] Flaps C and D receive reaction forces from flaps A and B and are easy to open outward. When flaps C and D open outward, the bottom surface or the top surface bulges outward. When the packaging box is placed on a flat surface, if the bottom surface bulges outward, the posture of the packaging box is unstable and it will shake. Also, when a plurality of packaging boxes are stacked vertically, if the bottom surface and the top surface bulge outward, the stacked packaging boxes will tilt or fall over.

[0006] In one aspect of the present disclosure, it is preferable to provide a packaging box capable of suppressing the bottom surface and the top surface from bulging outward.

Means for Solving the Problems

[0007] One aspect of the present disclosure is a packaging box. The packaging box includes a rectangular tube-shaped body portion, a bottom surface, and a top surface. The body portion includes a first body piece, a second body piece adjacent to the first body piece, a third body piece adjacent to the second body piece, and a fourth body piece adjacent to the third body piece and the first body piece.

[0008] The bottom surface and the top surface each include a first flap connected to the first body piece via a first fold line, a second flap connected to the second body piece via a second fold line, a third flap connected to the third body piece via a third fold line, and a fourth flap connected to the fourth body piece via a fourth fold line.

[0009] The first flap and the third flap are overlapped on the second flap and the fourth flap from the outside. The first flap includes a first thin portion having a smaller thickness on the side opposite to the first fold line than on the side of the first fold line. The second flap includes a second thin portion having a smaller thickness on the side of the second fold line than any portion of the second flap. The third flap includes a third thin portion having a smaller thickness on the side opposite to the third fold line than on the side of the third fold line. The fourth flap includes a fourth thin portion having a smaller thickness on the side of the fourth fold line than any portion of the fourth flap.

[0010] In one aspect of the present disclosure, the packaging box can suppress the bottom surface and the top surface from bulging outward.

Brief Description of the Drawings

[0011]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Modes for Carrying Out the Invention

[0012] Exemplary embodiments of the present disclosure will be described with reference to the drawings. <First Embodiment> 1. Basic Configuration of Packaging Box 1 The basic configuration of the packaging box 1 will be described based on FIGS. 1 to 3. As shown in FIG. 1, when assembled, the packaging box 1 has a rectangular parallelepiped shape. The packaging box 1 is made of, for example, cardboard. The packaging box 1 includes a rectangular tube-shaped body portion 3, a bottom surface 5, and a top surface 7.

[0013] As shown in FIGS. 1 and 2, the body portion 3 includes a first body piece 11, a second body piece 12, a third body piece 13, and a fourth body piece 14. The first body piece 11 is adjacent to the second body piece 12 and the fourth body piece 14 via creases respectively. The second body piece 12 is adjacent to the first body piece 11 and the third body piece 13 via creases respectively. The third body piece 13 is adjacent to the second body piece 12 and the fourth body piece 14 via creases respectively. The fourth body piece 14 is adjacent to the third body piece 13 and the first body piece 11 via creases respectively.

[0014] The shapes of the first body piece 11, the second body piece 12, the third body piece 13, and the fourth body piece 14 are all rectangles. The shape and size of the first body piece 11 are equal to those of the third body piece 13. The shape and size of the second body piece 12 are equal to those of the fourth body piece 14. The first body piece 11 and the third body piece 13 are, for example, wider than the second body piece 12 and the fourth body piece 14.

[0015] The packaging box 1 includes a first flap 21, a second flap 22, a third flap 23, and a fourth flap 24. The first flap 21 is connected to the first body piece 11 via a first crease 31. The second flap 22 is connected to the second body piece 12 via a second crease 32. The third flap 23 is connected to the third body piece 13 via a third crease 33. The fourth flap 24 is connected to the fourth body piece 14 via a fourth crease 34.

[0016] The first crease 31, the second crease 32, the third crease 33, and the fourth crease 34 are on one plane. Also, in the developed view of the packaging box 1 shown in FIG. 2, the first crease 31, the second crease 32, the third crease 33, and the fourth crease 34 are on a straight line.

[0017] The shapes of the first flap 21, the second flap 22, the third flap 23, and the fourth flap 24 are each rectangular. The shape and size of the first flap 21 are equal to the shape and size of the third flap 23. The shape and size of the third flap 23 are equal to the shape and size of the fourth flap 24. For example, the first flap 21 and the third flap 23 are wider than the second flap 22 and the fourth flap 24.

[0018] As shown in FIG. 1, the first flap 21, the second flap 22, the third flap 23, and the fourth flap 24 form the top surface 7 when the packaging box 1 is assembled. When assembling the packaging box 1, as shown in FIG. 3, from the state where the first flap 21, the second flap 22, the third flap 23, and the fourth flap 24 are open, first, the second flap 22 and the fourth flap 24 are bent inward to the state shown in FIG. 1. Next, the first flap 21 and the third flap 23 are bent inward to the state shown in FIG. 1. The first flap 21 and the third flap 23 are overlapped on the second flap 22 and the fourth flap 24 from the outside.

[0019] As shown in FIGS. 1 and 2, the packaging box 1 includes a first flap 41, a second flap 42, a third flap 43, and a fourth flap 44. The first flap 41 is connected to the first body piece 11 via the first fold line 51. The second flap 42 is connected to the second body piece 12 via the second fold line 52. The third flap 43 is connected to the third body piece 13 via the third fold line 53. The fourth flap 44 is connected to the fourth body piece 14 via the fourth fold line 54.

[0020] The first fold line 51, the second fold line 52, the third fold line 53, and the fourth fold line 54 are on one plane. Also, in the developed view of the packaging box 1 shown in FIG. 2, the first fold line 51, the second fold line 52, the third fold line 53, and the fourth fold line 54 are on a straight line.

[0021] The first fold line 51 is located on the side opposite to the first fold line 31 with respect to the first body piece 11. The second fold line 52 is located on the side opposite to the second fold line 32 with respect to the second body piece 12. The third fold line 53 is located on the side opposite to the third fold line 33 with respect to the third body piece 13. The fourth fold line 54 is located on the side opposite to the fourth fold line 34 with respect to the fourth body piece 14.

[0022] The shapes and sizes of the first flap 41, the second flap 42, the third flap 43, and the fourth flap 44 are the same as the shapes and sizes of the first flap 21, the second flap 22, the third flap 23, and the fourth flap 24, respectively.

[0023] As shown in FIG. 1, the first flap 41, the second flap 42, the third flap 43, and the fourth flap 44 form the bottom surface 5 when the packaging box 1 is assembled. When assembling the packaging box 1, first, the second flap 42 and the fourth flap 44 are bent inward to the state shown in FIG. 1. Next, the first flap 41 and the third flap 43 are bent inward to the state shown in FIG. 1. The first flap 41 and the third flap 43 are overlapped on the second flap 42 and the fourth flap 44 from the outside.

[0024] 2. Configuration of Each Flap As shown in FIG. 2, the first flap 21 includes a first thin portion 61. The first thin portion 61 is the portion of the first flap 21 on the side opposite to the first fold line 31. The first thin portion 61 is a portion with a smaller thickness compared to the portion of the first flap 21 on the side of the first fold line 31 (i.e., the portion that is not the first thin portion 61).

[0025] When the thickness of the portion of the first flap 21 on the side of the first fold line 31 is 100, the thickness of the first thin portion 61 is, for example, 40 or more and 85 or less. When the total area of the first flap 21 is 100, the area of the first thin portion 61 is, for example, 20 or more and 60 or less.

[0026] The basic form of the first thin part 61 is a strip shape extending parallel to the first fold line 31. However, at both ends of the first thin part 61 in the longitudinal direction of the first fold line 31, it protrudes toward the first fold line 31. The first thin part 61 can be formed, for example, by crushing the portion of the first flap 21 corresponding to the first thin part 61.

[0027] The first flap 41 also includes the first thin part 61, similar to the first flap 21. However, in the first flap 41, the first thin part 61 is the part on the side opposite to the first fold line 51. As shown in FIG. 2, the second flap 22 includes a second thin part 63, an outer thin part 65, and an inner grid line 67 of the second flap.

[0028] The second thin part 63 is the part of the second flap 22 on the side of the second fold line 32. The second thin part 63 is a part with a smaller thickness compared to the part that is neither the second thin part 63 nor the outer thin part 65 in the second flap 22 (hereinafter referred to as the normal part 69).

[0029] When the thickness of the normal part 69 is set to 100, the thickness of the second thin part 63 is, for example, 50 or more and 80 or less. When the total area of the second flap 22 is set to 100, the area of the second thin part 63 is, for example, 25 or more and 75 or less.

[0030] The form of the second thin part 63 is a strip shape extending parallel to the second fold line 32. The second thin part 63 can be formed, for example, by crushing the portion of the second flap 22 corresponding to the second thin part 63.

[0031] The outer thin part 65 is the part of the second flap 22 on the side opposite to the second fold line 32. The outer thin part 65 is a part with a smaller thickness compared to the normal part 69. When the thickness of the normal part 69 is set to 100, the thickness of the outer thin part 65 is, for example, 40 or more and 85 or less. When the total area of the second flap 22 is set to 100, the area of the outer thin part 65 is, for example, 20 or more and 60 or less.

[0032] The shape of the outer thin part 65 is a strip shape extending parallel to the second fold line 32. The outer thin part 65 can be formed, for example, by crushing the portion of the second flap 22 corresponding to the outer thin part 65.

[0033] The normal part 69 is located between the second thin part 63 and the outer thin part 65. The shape of the normal part 69 is a strip shape extending parallel to the second fold line 32. The second flap inner ruled line 67 is provided at the boundary between the second thin part 63 and the normal part 69. The second flap inner ruled line 67 extends parallel to the second fold line 32. The second flap inner ruled line 67 reaches from one end of the second flap 22 to the opposite end.

[0034] The second flap 42 also includes a second thin part 63, an outer thin part 65, and a second flap inner ruled line 67, similar to the second flap 22. However, in the second flap 42, the second thin part 63 is the part on the side of the second fold line 52. Also, in the second flap 42, the outer thin part 65 is the part on the side opposite to the second fold line 52.

[0035] As shown in FIG. 2, the third flap 23 includes a third thin part 71. The third thin part 71 is the part of the third flap 23 on the side opposite to the third fold line 33. The third thin part 71 is a part with a smaller thickness compared to the part of the third flap 23 on the side of the third fold line 33 (that is, the part that is not the third thin part 71).

[0036] When the thickness of the part of the third flap 23 on the side of the third fold line 33 is set to 100, the thickness of the third thin part 71 is, for example, 50 or more and 80 or less. When the total area of the third flap 23 is set to 100, the area of the third thin part 71 is, for example, 25 or more and 75 or less.

[0037] The basic form of the third thin-walled portion 71 is a strip-shaped form extending parallel to the third fold line 33. However, at both ends of the third thin-walled portion 71 in the longitudinal direction of the third fold line 33, it protrudes toward the third fold line 33. The third thin-walled portion 71 can be formed, for example, by crushing the portion corresponding to the third thin-walled portion 71 in the third flap 23.

[0038] The third flap 43 also includes the third thin-walled portion 71, similar to the third flap 23. However, in the third flap 43, the third thin-walled portion 71 is the portion on the side opposite to the third fold line 53. As shown in FIG. 2, the fourth flap 24 includes a fourth thin-walled portion 73, an outer thin-walled portion 75, and a fourth flap inner grid line 77.

[0039] The fourth thin-walled portion 73 is the portion of the fourth flap 24 on the side of the fourth fold line 34. The fourth thin-walled portion 73 is a portion with a smaller thickness compared to the portion that is neither the fourth thin-walled portion 73 nor the outer thin-walled portion 75 in the fourth flap 24 (hereinafter referred to as the normal portion 79).

[0040] When the thickness of the normal portion 79 is 100, the thickness of the fourth thin-walled portion 73 is, for example, 50 or more and 85 or less. When the total area of the fourth flap 24 is 100, the area of the fourth thin-walled portion 73 is, for example, 25 or more and 75 or less.

[0041] The form of the fourth thin-walled portion 73 is a strip-shaped form extending parallel to the fourth fold line 34. The fourth thin-walled portion 73 can be formed, for example, by crushing the portion corresponding to the fourth thin-walled portion 73 in the fourth flap 24.

[0042] The outer thin-walled portion 75 is the portion of the fourth flap 24 on the side opposite to the fourth fold line 34. The outer thin-walled portion 75 is a portion with a smaller thickness compared to the normal portion 79. When the thickness of the normal portion 79 is 100, the thickness of the outer thin-walled portion 75 is, for example, 40 or more and 85 or less. When the total area of the fourth flap 24 is 100, the area of the outer thin-walled portion 75 is, for example, 20 or more and 60 or less.

[0043] The shape of the outer thin-walled portion 75 is a strip shape extending parallel to the fourth fold line 34. The outer thin-walled portion 75 can be formed, for example, by crushing a portion corresponding to the outer thin-walled portion 75 in the fourth flap 24.

[0044] The normal portion 79 is located between the fourth thin-walled portion 73 and the outer thin-walled portion 75. The shape of the normal portion 79 is a strip shape extending parallel to the fourth fold line 34. The fourth flap inner ruled line 77 is provided at the boundary between the fourth thin-walled portion 73 and the normal portion 79. The fourth flap inner ruled line 77 extends parallel to the fourth fold line 34. The second flap inner ruled line 67 reaches from one end of the fourth flap 24 to the opposite end.

[0045] The fourth flap 44 also includes a fourth thin-walled portion 73, an outer thin-walled portion 75, and a fourth flap inner ruled line 77, similar to the fourth flap 24. However, in the fourth flap 44, the fourth thin-walled portion 73 is the portion on the side of the fourth fold line 54. Also, in the fourth flap 44, the outer thin-walled portion 75 is the portion on the side opposite to the fourth fold line 54.

[0046] 3. Effects of the packaging box 1 (1A) As shown in FIG. 1, the first flap 21 and the third flap 23 overlap the second thin-walled portion 63 provided in the second flap 22 from the outside. Also, the first flap 21 and the third flap 23 overlap the fourth thin-walled portion 73 provided in the fourth flap 24 from the outside.

[0047] Since the second thin-walled portion 63 and the fourth thin-walled portion 73 are portions with a small thickness, the first flap 21 and the third flap 23 are less likely to receive a reaction force from the outside. Therefore, the first flap 21 and the third flap 23 are less likely to bulge outward. As a result, the top surface 7 is less likely to bulge outward.

[0048] Also, the first flap 41 and the third flap 43 overlap the second thin-walled portion 63 provided in the second flap 42 from the outside. Also, the first flap 41 and the third flap 43 overlap the fourth thin-walled portion 73 provided in the fourth flap 44 from the outside.

[0049] Since the second thin-walled portion 63 and the fourth thin-walled portion 73 are portions with a small thickness, the first flap 41 and the third flap 43 are less likely to receive a reaction force outward. Therefore, the first flap 41 and the third flap 43 are less likely to bulge outward. As a result, the bottom surface 5 is less likely to bulge outward.

[0050] (1B) As shown in FIGS. 2 and 4, the first flap 21 includes the first thin-walled portion 61. Also, the third flap 23 includes the third thin-walled portion 71. The first thin-walled portion 61 is located near the center of the top surface 7 and is a portion with a small thickness. The third thin-walled portion 71 is located near the center of the top surface 7 and is a portion with a small thickness. Therefore, as shown in FIG. 4, the surface near the center of the top surface 7 is less likely to bulge outward compared to the virtual surface 81 of the top surface 7 when it is assumed that the first thin-walled portion 61 and the third thin-walled portion 71 do not exist.

[0051] Also, the first flap 41 includes the first thin-walled portion 61. Also, the third flap 43 includes the third thin-walled portion 71. The first thin-walled portion 61 is located near the center of the bottom surface 5 and is a portion with a small thickness. The third thin-walled portion 71 is located near the center of the bottom surface 5 and is a portion with a small thickness. Therefore, the surface near the center of the bottom surface 5 is less likely to bulge outward compared to the virtual surface 83 of the bottom surface 5 when it is assumed that the first thin-walled portion 61 and the third thin-walled portion 71 do not exist.

[0052] (1C) FIG. 5 shows the configuration of a packaging box 101 that has basically the same configuration as the packaging box 1 but does not include the second flap inner ruled line 67 and the fourth flap inner ruled line 77. FIG. 5 shows a state in which the packaging box 101 is divided into two along a cross-section parallel to the first body piece 11 and the third body piece 13.

[0053] When the packaging box 101 is placed on the ground with the bottom surface 5 facing downwards and a downward force F is applied to the top surface 7, the portion of the second flap 42 on the side of the second fold line 52 is pushed downwards. As a result, a force that causes the second flap 42 to rise upwards U is generated. Also, the portion of the fourth flap 44 on the side of the fourth fold line 54 is pushed downwards. As a result, a force that causes the fourth flap 44 to rise upwards U is generated.

[0054] Figure 6 shows a state in which the product 103 is accommodated in the packaging box 101, and an upward U-shaped lifting force is generated on the second flap 42 and the fourth flap 44. For example, when the center of gravity of the product 103 is on the side of the second flap 42, the second flap 42 does not rise due to the weight of the product 103. On the other hand, the fourth flap 44 rises. As a result, the product 103 tilts.

[0055] In contrast, as shown in FIG. 7, the packaging box 1 includes a second flap inner grid line 67 and a fourth flap inner grid line 77. The second flap 42 easily bends at the second flap inner grid line 67. The fourth flap 44 easily bends at the fourth flap inner grid line 77. Note that FIG. 7 shows a state in which the packaging box 1 is divided into two by a cross section parallel to the first body piece 11 and the third body piece 13.

[0056] Figure 8 shows a state in which the product 103 is accommodated in the packaging box 1. There is a bias in the center of gravity of the product 103. An upward U-shaped lifting force is generated on the second flap 42 and the fourth flap 44. Even in this case, by bending the second flap 42 at the second flap inner grid line 67 and bending the fourth flap 44 at the fourth flap inner grid line 77, it is possible to suppress the tilting of the product 103.

[0057] 4. Test for Confirming the Effect of the Packaging Box 1 (4-1) Measurement of Compressive Strength and Bending Strength For the packaging box 1, the compressive strength and the flexural strength were measured. The method for measuring the compressive strength was in accordance with the method specified in JIS Z0212. The method for measuring the flexural strength was in accordance with the method specified in JCS T0001. In Table 1, "Upper flexural strength" means the average value of the measured values of the flexural strength at the first fold 31, the second fold 32, the third fold 33, and the fourth fold 34. In Table 1, "Lower flexural strength" means the average value of the measured values of the flexural strength at the first fold 41, the second fold 42, the third fold 43, and the fourth fold 44. In Table 1, "Positive" means the flexural strength when folding inward the packaging box 1. In Table 1, "Negative" means the flexural strength when folding outward the packaging box 1. The measurement results are shown in Table 1.

[0058]

Table 1

[0059] Also, the same measurements were performed on the packaging boxes R1 and R2. The packaging box R1 basically has the same form as the packaging box 1. However, the packaging box R1 does not include the first thin part 61, the second thin part 63, the outer thin part 65, the second flap inner ruled line 67, the third thin part 71, the fourth thin part 73, the outer thin part 75, and the fourth flap inner ruled line 77.

[0060] Also, in the packaging box R1, as shown in FIG. 9, the second fold 32 and the fourth fold 34 are in positions shifted in the X direction compared to the first fold 31 and the third fold 33. The X direction is the direction toward the center of the packaging box R1. Also, the second fold 52 and the fourth fold 54 are in positions shifted in the Y direction compared to the first fold 51 and the third fold 53. The Y direction is the direction toward the center of the packaging box R1.

[0061] The packaging box R2 basically has the same form as the packaging box 1. However, the packaging box R2 does not include the first thin part 61, the second thin part 63, the outer thin part 65, the second flap inner ruled line 67, the third thin part 71, the fourth thin part 73, the outer thin part 75, and the fourth flap inner ruled line 77. The packaging box 1 had a higher compressive strength than the packaging box R1.

[0062] (4-2) Inclination Test As shown in Fig. 10, four packaging boxes 1 were stacked on a horizontal floor 105. The lowermost packaging box 1 is designated as packaging box 1_1. The second packaging box 1 from the bottom is designated as packaging box 1_2. The third packaging box 1 from the bottom is designated as packaging box 1_3. The fourth packaging box 1 from the bottom is designated as packaging box 1_4. The orientations of packaging boxes 1_1 to 1_4 were such that the bottom surface 5 was on the lower side and the top surface 7 was on the upper side, respectively.

[0063] In Fig. 10, in each of the packaging boxes 1_1 to 1_4, the fourth body piece 14 is located on the front side. The right side in Fig. 10 is designated as the right side R, and the left side is designated as the left side L. The gap between packaging box 1_3 and packaging box 1_4 on the left side L is designated as C_34L. The gap between packaging box 1_2 and packaging box 1_3 on the left side L is designated as C_23L. The gap between packaging box 1_1 and packaging box 1_2 on the left side L is designated as C_12L. The average value of C_34L, C_23L, and C_12L is designated as C_aveL.

[0064] The gap between packaging box 1_3 and packaging box 1_4 on the right side R is designated as C_34R. The gap between packaging box 1_2 and packaging box 1_3 on the right side R is designated as C_23R. The gap between packaging box 1_1 and packaging box 1_2 on the right side R is designated as C_12R. The average value of C_34R, C_23R, and C_12R is designated as C_aveR.

[0065] Let the average value of C_34L, C_23L, C_12L, C_34R, C_23R, and C_12R be C_ave. Let the height of the top surface 7 of the packaging box 1_4 on the left side L be the four - level stacking height_L. Let the height of the top surface 7 of the packaging box 1_4 on the right side R be the four - level stacking height_R. The definition of the inclination in Table 2 is as follows. When the four packaging boxes 1 are tilted as a whole to the right side R, the horizontal distance between the end on the right side R of the top surface 7 of the packaging box 1_4 and the end on the right side R of the bottom surface 5 of the packaging box 1_1 is defined as the inclination. When the four packaging boxes 1 are tilted as a whole to the left side L, the horizontal distance between the end on the left side L of the top surface 7 of the packaging box 1_4 and the end on the left side L of the bottom surface 5 of the packaging box 1_1 is defined as the inclination. The measurement results of each numerical value are shown in Table 2.

[0066]

Table 2

[0067] Also, the packaging boxes R1 and R2 were measured in the same way respectively. The packaging box 1 had smaller C_ave and inclination compared to the packaging box R2. Note that the larger the bottom surface 5 and the top surface 7 bulge outwards, the larger the C_ave and the inclination. Therefore, the bottom surface 5 and the top surface 7 of the packaging box 1 did not bulge outwards compared to the packaging box R2.

[0068] (4 - 3) Knock - down test As shown in Fig. 10, the position on the left side L and above of the packaging box 1_4 was set as P_4L. A force to the right side R was applied to P_4L, and the magnitude of the force was gradually increased. The magnitude of the force when any one of the packaging boxes 1_1 - 1_4 fell or skidded sideways was set as F_4L.

[0069] The position on the right side R and above of the packaging box 1_4 was set as P_4R. A force to the left side L was applied to P_4R, and the magnitude of the force was gradually increased. The magnitude of the force when any one of the packaging boxes 1_1 - 1_4 fell or skidded sideways was set as F_4R.

[0070] The position on the left side L and above in the packaging box 1_2 was designated as P_2L. A force to the right side R was applied to P_2L, and the magnitude of the force was gradually increased. The magnitude of the force when any one of the packaging boxes 1_1 to 1_4 toppled or slid sideways was designated as F_2L.

[0071] The position on the right side R and above in the packaging box 1_2 was designated as P_2R. A force to the left side L was applied to P_2R, and the magnitude of the force was gradually increased. The magnitude of the force when any one of the packaging boxes 1_1 to 1_4 toppled or slid sideways was designated as F_2R.

[0072] The measurement results of F_4L, F_4R, F_2L, and F_2R are shown in Table 3. Also, the states of the packaging boxes 1_1 to 1_4 when any one of F_4L, F_4R, F_2L, and F_2R was applied are shown in Table 3. Also, the average values of F_4L and F_4R, and the average values of F_2L and F_2R are shown in Table 3.

[0073]

Table 3

[0074] Also, the packaging boxes R1 and R2 were similarly measured. For the packaging box 1, the values of F_4L, F_4R, F_2L, and F_2R were larger than those of the packaging box R2. Note that the larger the bottom surface 5 and the top surface 7 bulge outward, the smaller the values of F_4L, F_4R, F_2L, and F_2R. Therefore, for the packaging box 1, the bottom surface 5 and the top surface 7 did not bulge outward as much as those of the packaging box R2. <Other Embodiments> As described above, the embodiments of the present disclosure have been described. However, the present disclosure is not limited to the above-described embodiments and can be implemented with various modifications.

[0075] (1) The packaging box 1 may not include the outer thin-walled portions 65 and 75. (2) The material of the packaging box 1 may be a material other than cardboard. (3) In each of the above embodiments, the functions of one component may be shared among a plurality of components, or the functions of a plurality of components may be exerted by one component. Also, a part of the configuration of each of the above embodiments may be omitted. Further, at least a part of the configuration of each of the above embodiments may be added to, replaced with, etc., the configuration of other above embodiments.

[0076] (4) In addition to the packaging box 1 described above, the present disclosure can also be realized in various forms such as a system including the components of the packaging box 1, a method for manufacturing the packaging box, etc.

Explanation of Reference Numerals

[0077] 1... Packaging box, 3... Barrel part, 5... Bottom surface, 7... Top surface, 11... First barrel piece, 12... Second barrel piece, 13... Third barrel piece, 14... Fourth barrel piece, 21, 41... First flap, 22, 42... Second flap, 23, 43... Third flap, 24, 44... Fourth flap, 31, 51... First fold line, 32, 52... Second fold line, 33, 53... Third fold line, 34, 54... Fourth fold line, 61... First thin part, 63... Second thin part, 65, 75... Outer thin part, 67... Inner grid line of the second flap, 69, 79... Normal part, 71... Third thin part, 73... Fourth thin part, 77... Inner grid line of the fourth flap, 81, 83... Virtual surface

Claims

1. A packaging box comprising a rectangular tube-shaped body, a bottom surface, and a top surface, wherein the body comprises a first body piece, a second body piece adjacent to the first body piece, a third body piece adjacent to the second body piece, and a fourth body piece adjacent to the third body piece and the first body piece, and the bottom surface and the top surface each comprise a first flap connected to the first body piece via a first fold line, a second flap connected to the second body piece via a second fold line, a third flap connected to the third body piece via a third fold line, and a fourth flap connected to the fourth body piece via a fourth fold line, and the first flap and the third flap are overlapped on the second flap and the fourth flap from the outside, the first flap has a first thin portion on the side opposite to the first fold line and having a smaller thickness than the side of the first fold line, the second flap has a second thin portion on the side of the second fold line and having a smaller thickness than any portion of the second flap, the third flap has a third thin portion on the side opposite to the third fold line and having a smaller thickness than the side of the third fold line, and the fourth flap has a fourth thin portion on the side of the fourth fold line and having a smaller thickness than any portion of the fourth flap, a packaging box.

2. The packaging box according to Claim 1, wherein the second flap has a second flap inner grid line extending along the second fold line, and the fourth flap has a fourth flap inner grid line extending along the fourth fold line, a packaging box.

3. The packaging box according to Claim 1 or 2, wherein the first thin portion has a shape protruding in the direction of the first fold line on the sides of both ends of the first fold line, and the third thin portion has a shape protruding in the direction of the third fold line on the sides of both ends of the third fold line, a packaging box.

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