Packing box

Abstract

To provide a packing box which can inhibit lifting of a lid part caused by a crease.SOLUTION: A packing box 3 has a first flap 62, a second flap 63, a third flap 64, and a fourth flap 65. The first flap 62 has an inserted part 70 which is a cutout. A second flap 23 has: an insertion piece 71 located adjacent to a slit 72; an insertion assisting polygonal line 37 which makes a mountain fold in the second flap 63; and correction pieces 38 each defined by a cut line formed so as to protrude from the insertion assisting polygonal line 37 to a tip side. In a state that the insertion piece 71 is inserted into the inserted part 70, the second flap 63 overlaps with outer surfaces of the first flap 62 and the third flap 64 in a portion excluding the insertion piece 71, and each correction piece 38 is pushed down and placed in contact with an edge of a removal hole 39 formed along a contour of the cut line by its restoring force while exerting a friction force to generate a correction force to correct a crease in the insertion assisting polygonal line 37 of the second flap 63.SELECTED DRAWING: Figure 12

Description

[Technical field]

[0001] The present invention relates to a packaging box. [Background technology]

[0002] A packaging box is known in which the upper and lower ends of four surrounding walls are closed by a number of flaps connected to each wall (Patent Document 1). An insertion receiving portion having a cut-and-raised structure is provided on both sides of a first flap, and an insertion portion to be inserted into the insertion receiving portion is provided on both sides of a second flap. An insertion assist fold line (lead crease) is provided on both end edges of the second flap. By bending the second flap along the insertion assist fold line, the tip of the insertion portion is directed toward the insertion receiving portion, making it easier to insert the insertion portion into the interior through the insertion receiving portion. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2005-8221 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the above-mentioned packaging box, the second flap may be lifted up due to a fold at the insertion auxiliary fold line (lead crease), and there is a risk that the insertion portion may be pulled out of the inserted portion due to vibration during transportation, for example, and the box may be opened.

[0005] In order to solve the above problem, the present invention provides a packaging box that can prevent a lid from floating up due to a crease. [Means for solving the problem]

[0006] In order to achieve the above-mentioned object, a packaging box of the present invention includes a peripheral wall formed into a cylindrical shape by alternately connecting a pair of first side walls and a pair of second side walls, and a lid portion connected to at least one of both ends in an axial direction of the peripheral wall and closing an opening of the peripheral wall, the lid portion having a first flap and a third flap connected to one end in the axial direction of the pair of first side walls and folded inwardly of the peripheral wall, and a second flap and a fourth flap connected to one end in the axial direction of the pair of second side walls and folded inwardly of the peripheral wall, the first flap having an insertion receiving portion formed in a state penetrating in a thickness direction, the second flap having an insertion piece formed on a tip side and inserted into the insertion receiving portion, an insertion auxiliary fold line formed on a base end side of the insertion piece and causing the second flap to mountain-fold when the insertion piece is inserted into the insertion receiving portion, and a fold line extending from the insertion auxiliary fold line to a tip side and a correction piece defined by a cutting line formed so as to protrude toward at least one of the base ends, wherein the insertion portion is a notch extending from the tip of the first flap toward the base end, and the insertion piece is formed as a part of the second flap adjacent to a slit cut from the tip of the second flap toward the base end, and when the first flap, the fourth flap, the third flap and the second flap are folded in this order toward the inside of the peripheral wall and the insertion piece is inserted into the insertion portion, the second flap overlaps with the outer surfaces of parts of the adjacent first flap and third flap except for the insertion piece, and the correction piece is pushed in and comes into frictional contact with the edge of the punch hole that follows the contour of the cutting line due to its own restoring force, generating a correction force that corrects the fold crease at the insertion auxiliary fold line of the second flap.

[0007] In this case, a finger hole may be cut out at the tip of the first flap and near the inserted portion, so that an operator can insert their finger to lift part of the first flap when inserting the insertion piece into the inserted portion.

[0008] In this case, a pressing portion is provided on the second flap closer to the first flap than the slit, and the insertion piece is provided on the opposite side of the pressing portion across the slit, and when the insertion piece is inserted into the inserted portion, the pressing portion overlaps with the outer surface of a portion of the first flap and clamps the first flap between the pressing portion and the insertion piece. Effect of the Invention

[0009] According to the present invention, it is possible to suppress lifting of the lid portion due to a crease. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a perspective view showing a packaging box according to a first embodiment of the present invention. [Diagram 2] FIG. 1 is a plan view showing a blank for a packaging box according to a first embodiment of the present invention. [Diagram 3] 1 is a plan view showing a portion of a first bottom flap and a second bottom flap of a packaging box according to a first embodiment of the present invention. FIG. [Figure 4] FIG. 2 is a perspective view illustrating a process of assembling the packaging box according to the first embodiment of the present invention. [Diagram 5] FIG. 2 is a plan view showing the right part of the packaging box according to the first embodiment of the present invention. [Figure 6] 6 is a cross-sectional view taken along line VI-VI of FIG. 5. [Figure 7] FIG. 7 is a cross-sectional view taken along line VII-VII of FIG. 5. [Figure 8] FIG. 11 is a plan view showing the right part of the packaging box according to a modified example of the first embodiment of the present invention. [Figure 9] FIG. 11 is a perspective view showing a packaging box according to a second embodiment of the present invention. [Figure 10] FIG. 11 is a plan view showing a blank for a packaging box according to a second embodiment of the present invention. [Figure 11] 10A to 10C are perspective views illustrating a process of assembling a packaging box according to a second embodiment of the present invention. [Figure 12] FIG. 11 is a perspective view showing a packaging box according to a third embodiment of the present invention. [Figure 13] FIG. 11 is a plan view showing a blank for a packaging box according to a third embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, an embodiment of the present invention will be described with reference to the attached drawings. Note that Fr, Rr, L, R, U, and D shown in the drawings indicate front, rear, left, right, top, and bottom. The front-rear direction (first direction), left-right direction (second direction), and up-down direction are mutually perpendicular. Terms indicating directions and positions are used in this specification, but these terms are used for convenience of explanation and do not limit the technical scope of the present invention. In addition, the terms indicating directions and positions are based on the directions and positions in the state in which the packaging box is assembled and used.

[0012] [First embodiment] A packaging box 1 according to a first embodiment will be described with reference to Fig. 1 to Fig. 4. Fig. 1 is a perspective view showing the packaging box 1. Fig. 2 is a plan view showing a blank 5 of the packaging box 1. Fig. 3 is a plan view showing a part of the first bottom flap 22D and the second bottom flap 23D.

[0013] As shown in FIG. 1, the packaging box 1 includes a peripheral wall W formed in a substantially rectangular cylindrical shape, and lids 10U and 10D that are connected to both upper and lower ends of the peripheral wall W and close the openings at both upper and lower ends of the peripheral wall W. The lids 10U and 10D are held in a state in which the openings are closed without using adhesive tape or adhesives, as will be described in detail later. The lid 10D includes a pair of first lower flaps 22D that are folded inwardly of the peripheral wall W, and a pair of second lower flaps 23D that are folded inwardly of the peripheral wall W and overlapped on the outside of a part of the pair of first lower flaps 22D (see FIG. 2). The lid 10U includes a pair of first upper flaps 22U and a pair of second upper flaps 23U, similar to the lid 10D.

[0014] The packaging box 1 is formed by assembling blanks 5 shown in FIG. 2. The blanks 5 are formed by punching out a single piece of cardboard sheet made of paper using a die or the like. The cardboard sheet is, for example, a double-sided cardboard sheet in which a front liner 9B and a back liner 9C (see FIG. 6, etc.) are bonded to a corrugated core 9A. Note that FIGS. 2 and 3 show the front liner 9B side (the outer surface of the packaging box 1). In this specification, the direction parallel to the core 9A of the cardboard sheet is referred to as the "corrugation direction," and the direction perpendicular to the corrugation direction is referred to as the "flow direction." In the drawings, "X" indicates the "corrugation direction," and "Y" indicates the "flow direction."

[0015] [blank] 2, the blank 5 includes a pair of first side walls 20, a pair of second side walls 21, a pair of first lower flaps 22D, a pair of second lower flaps 23D, a pair of first upper flaps 22U, and a pair of second upper flaps 23U. Since the pair of portions have substantially the same shape, hereinafter, unless otherwise specified, only one portion will be described.

[0016] <First side wall, second side wall> A pair of first side walls 20 and a pair of second side walls 21 are alternately connected from one side to the other in the flow direction via a first fold line L1. The first side walls 20 and the second side walls 21 are formed in a substantially rectangular shape. In detail, the first side walls 20 are formed in a substantially rectangular shape that is longer in the flow direction than the second side walls 21. A joint piece 24 is connected to one end of the first side walls 20 in the flow direction via the first fold line L1.

[0017] <First lower flap, second lower flap> The first lower flap 22D is connected to one end (lower end) of the first side wall 20 in the step direction via the second fold line L2. The first lower flap 22D is formed in a substantially rectangular shape, and its dimension in the step direction (extension dimension) is set to be slightly longer than half the dimension in the flow direction of the second side wall 21. A step-destroyed portion 25 is formed at the tip side (free end side) of the first lower flap 22D by depressing the core 9A from the back liner 9C side to make it thinner (see the hatched portion in FIG. 2). The second lower flap 23D is connected to one end (lower end) of the second side wall 21 in the step direction via the second fold line L2. The second lower flap 23D is formed in a substantially rectangular shape, and its extension dimension is substantially the same as the extension dimension of the first lower flap 22D.

[0018] <First lower flap, second lower flap> The first upper flap 22U is connected to the other end (upper end) in the step direction of the first side wall 20 via the third fold line L3. The second upper flap 23U is connected to the other end (upper end) in the step direction of the second side wall 21 via the third fold line L3. The first upper flap 22U has approximately the same shape as the first lower flap 22D, and the second upper flap 23U has approximately the same shape as the second lower flap 23D.

[0019] The first to third fold lines L1 to L3 are general-purpose creases formed by crushing the cardboard sheet in the thickness direction from the back liner 9C side. The general-purpose creases have the function of folding the cardboard sheet so that the back liner 9C faces inward (forward folding). The first to third fold lines L1 to L3 are not limited to general-purpose creases, and may be any structure for folding the cardboard sheet, such as perforation lines formed with multiple cuts at predetermined intervals or lead creases formed with perforation lines on general-purpose creases.

[0020] [Lock structure] Both the upper and lower lids 10U and 10D are provided with lock structures 26U and 26D for keeping the opening of the peripheral wall W closed. Since the upper and lower lock structures 26U and 26D have the same structure, the following description will focus on the lower lock structure 26D. For convenience of explanation, the description common to the upper and lower lock structures 26U and 26D will be given with Arabic numerals only. For convenience of explanation, the description common to the first upper flap 22U and the first lower flap 22D will be given with Arabic numerals only. For convenience of explanation, the description common to the first upper flap 22U and the first lower flap 22D will be given with Arabic numerals only. The description common to the second upper flap 23U and the second lower flap 23D will be given with Arabic numerals only.

[0021] As shown in FIG. 2, the lock structure 26 has two pairs of insertion receiving portions 30, two pairs of insertion pieces 35, a pair of pressing portions 36, a pair of insertion auxiliary fold lines 37, and a pair of correction pieces 38. The two pairs of insertion receiving portions 30 are formed on both sides of the pair of first flaps 22 in the flow direction. The two pairs of insertion pieces 35 and the pair of pressing portions 36 are formed on the tip side (free end side) of the pair of second flaps 23 in the step direction. The pair of insertion auxiliary fold lines 37 and the pair of correction pieces 38 are formed in the middle part (proximal end side of the insertion pieces 35) of the pair of second flaps 23 in the step direction. Note that the tip side of the insertion auxiliary fold lines 37 of each second flap 23 in the step direction is formed narrower in the flow direction than the proximal end side. For this reason, a step portion is formed at both ends of the second flap 23 in the flow direction.

[0022] Since the two inserted portions 30 formed on each first flap 22 are formed symmetrically with respect to a line that bisects the first flap 22 in the flow direction, the following description will focus on one inserted portion 30 with reference to Fig. 3. Also, since the two pairs of insertion pieces 35, the pair of pressing portions 36, the pair of insertion auxiliary fold lines 37, and the pair of correction pieces 38 formed on the pair of second flaps 23 have the same shape, the following description will focus on the pair of insertion pieces 35, the pressing portions 36, the insertion auxiliary fold lines 37, and the correction pieces 38 formed on one second flap 23 with reference to Fig. 3.

[0023] <Inserted part> The inserted portion 30 is formed in a state penetrating the first flap 22 in the thickness direction. Specifically, the inserted portion 30 has a cut and raised structure in which the pushing piece 31 is cut along the pushing cut line 32 while being folded at the pushing fold line 31A. The pushing fold line 31A (e.g., a general-purpose crease) extends parallel to the row direction at the end side in the flow direction of the first flap 22. The pushing cut line 32 is formed in a mountain shape so as to connect both ends of the pushing fold line 31A. The pushing piece 31 is formed in a range surrounded by the pushing fold line 31A and the pushing cut line 32.

[0024] The pressing cut line 32 has a straight cut portion 32A, an inclined cut portion 32B, and a bent cut portion 32C. The straight cut portion 32A extends parallel to the flow direction from one end of the pressing fold line 31A, which is the base end side of the first flap 22, toward the center of the first flap 22 in the flow direction. The inclined cut portion 32B is inclined toward the base end side of the first flap 22 from the other end of the pressing fold line 31A, which is the tip side of the first flap 22, toward the center of the first flap 22 in the flow direction. The bent cut portion 32C connects the tips of the straight cut portion 32A and the inclined cut portion 32B, and is formed in a crank shape in which the tip side of the first flap 22 protrudes toward the center of the first flap 22 in the flow direction. The pressing piece 31 is divided into the pressing fold line 31A and the pressing cut line 32 and is formed in a substantially L-shape (substantially rectangular shape).

[0025] Although details will be described later, by pushing in the pushing piece 31 and cutting a part of the first flap 22 along the pushing cutting line 32, an insertion hole 33 having a shape complementary to the pushing piece 31 is opened in the first flap 22. An inclined edge 33B is formed in the insertion hole 33 at the position cut along the inclined cutting portion 32B. Also, a one-side pressing portion 34 that protrudes inward of the insertion hole 33 is formed on the base end side of the first flap 22.

[0026] <Insert piece> The pair of insertion pieces 35 are formed on both sides in the flow direction at the tip side of the second flap 23. The insertion piece 35 is formed in a substantially rectangular shape with the corners on the tip side chamfered. The pair of insertion pieces 35 have a pair of protrusions 35A protruding so as to approach each other. As will be described in detail later, the pair of insertion pieces 35 are inserted into the above-mentioned inserted portion 30 (insertion hole 33). When the insertion piece 35 is inserted into the insertion hole 33, the protrusions 35A intersect with the inclined edge 33B of the insertion hole 33 and interfere with the inside of the inclined edge 33B.

[0027] <Pressing part> The pressing portion 36 is provided between the pair of insertion pieces 35 at the tip side of the second flap 23. The pressing portion 36 is formed in a generally trapezoid shape that gradually narrows in the flow direction toward the tip side. The dimension (extension) of the pressing portion 36 in the step direction is set to be slightly shorter than the dimension (extension) of the insertion piece 35 in the step direction. At the boundary between the pressing portion 36 and the pair of insertion pieces 35, a pair of cuts 36A are formed along a pair of oblique sides of the trapezoid. The base end of the cuts 36A is curved into a generally semicircular shape.

[0028] <Insertion auxiliary fold line> The insertion auxiliary fold line 37 is, for example, a general-purpose crease, and is formed parallel to the flow direction in the middle of the step direction of the second flap 23. The insertion auxiliary fold line 37 extends from a correction piece 38 (described later) to both ends in the flow direction of the second upper flap 23U. Although details will be described later, the insertion auxiliary fold line 37 causes the second flap 23 to make a mountain fold when the insertion piece 35 is inserted into the insertion receiving portion 30.

[0029] <Correction piece> The correction piece 38 is partitioned by a cutting line 38A formed so as to protrude from the insertion auxiliary broken line 37 toward the tip side of the second flap 23 at the middle part in the flow direction of the insertion auxiliary broken line 37. The correction piece 38 (cutting line 38A) is formed in a substantially trapezoidal shape that gradually widens in the flow direction toward the tip side of the second flap 23 (as it moves away from the insertion auxiliary broken line 37). The correction piece 38 is formed at an interval from the base end side of the pressing part 36. Although details will be described later, by pushing in the correction piece 38 and cutting a part of the second flap 23 along the cutting line 38A, a punched hole 39 having a shape complementary to that of the correction piece 38 opens in the second flap 23.

[0030] [Assembly of the packaging box] Next, with reference to FIGS. 1, 4 to 7, the assembly process of the packaging box 1 will be described. FIG. 4 is a perspective view for explaining the process of assembling the packaging box 1. FIG. 5 is a plan view showing the right part of the packaging box 1. FIG. 6 is a cross-sectional view taken along line VI-VI of FIG. 5. FIG. 7 is a cross-sectional view taken along line VII-VII of FIG. 5. Note that the packaging box 1 may be assembled manually by an operator or automatically or semi-automatically by an automatic box-making machine (not shown). Here, as an example, the case where an operator manually assembles the packaging box 1 will be described. Also, as an initial state before assembling the packaging box 1, the first side wall 20 and the second side wall 21 located on both outer sides in the flow direction of the blank 5 are bent along the first bending line L1, and the replacement piece 24 is adhered to the inner surface of the second side wall 21 on the opposite side, and it is assumed that the packaging box 1 is folded double (not shown).

[0031] The operator bends the pair of first side walls 20 and the pair of second side walls 21 at a substantially right angle along the first bending line L1. The pair of first side walls 20 face each other in the front-rear direction (first direction), the pair of second side walls 21 face each other in the left-right direction (second direction), and a peripheral wall W having openings at both upper and lower ends is formed (see FIGS. 1 and 4).

[0032] Next, the worker closes the lower opening of the peripheral wall W with the lid portion 10D. Note that the lid portion 10D (first lower flap 22D, second lower flap 23D) forms the bottom of the packaging box 1, but is directed upward in consideration of workability during assembly.

[0033] As shown in FIG. 4, the worker folds inward the pair of first lower flaps 22D connected to the pair of first side walls 20 at the second fold line L2. The pair of first lower flaps 22D overlap at the step-flattened portion 25 on the tip side. Next, the worker folds inward the pair of second lower flaps 23D connected to the pair of second side walls 21 at the second fold line L2 and overlaps the pair of first lower flaps 22D on both the left and right surfaces. At this time, the worker fixes the pair of second lower flaps 23D to the pair of first lower flaps 22D using the lock structure portion 26D. Note that the fixing procedure for the pair of second lower flaps 23D is the same, so the following description will be mainly focused on one second lower flap 23D.

[0034] The worker folds the second lower flap 23D at the insertion auxiliary fold line 37, and aligns the tips of the pair of insertion pieces 35 with the pair of inserted parts 30 (the pair of pushing pieces 31) provided on the pair of first lower flaps 22D. The worker pushes the pair of pushing pieces 31 into the inside of the peripheral wall W from above the pair of insertion pieces 35 (see the right side of FIG. 4). The pair of pushing pieces 31 are hollowed out from the first lower flap 22D along the pushing cutting line 32 while bending at the pushing fold line 31A, and a pair of insertion holes 33 are opened at the site where the pair of pushing pieces 31 are hollowed out. When the second lower flap 23D is folded at the insertion auxiliary fold line 37, the correction piece 38 is hollowed out along the cutting line 38A and protrudes outward.

[0035] The worker inserts the pair of insertion pieces 35 into the pair of insertion holes 33 (see the left side of FIG. 4) while folding the second lower flap 23D at the second fold line L2 and returning the second lower flap 23D that has been mountain-folded at the insertion auxiliary fold line 37 to a flat state. As shown in FIG. 4 and FIG. 5, the pair of insertion pieces 35 slide into the backside of the pair of one-side pressing portions 34, and the pair of one-side pressing portions 34 overlap the surfaces of the pair of insertion pieces 35. In addition, the pressing portions 36 overlap the surfaces of the tip sides (step-flattened portions 25) of the pair of first lower flaps 22D.

[0036] In this state, as shown in FIG. 6, the pair of first lower flaps 22D are sandwiched between the pair of insertion pieces 35 and the pressing portion 36. Also, as shown in FIG. 7, the insertion piece 35 is sandwiched between the pressing piece 31 and the pressing portion 34. Furthermore, as shown in FIG. 5, the protrusion 35A of the insertion piece 35 intersects with the inclined edge 33B (more precisely, the extension line of the inclined edge 33B) of the insertion hole 33 and overlaps with the back surface of the first lower flap 22D. These structures prevent the insertion piece 35 from being easily pulled out of the insertion hole 33. Note that the inclined edge 33B intersects with the protrusion 35A does not require that the protrusions 35A always intersect when the insertion piece 35 is inserted into the insertion hole 33, but means that the protrusions 35A intersect with the inclined edge 33B during the process of inserting (pulling out) the insertion piece 35 into the insertion hole 33.

[0037] Next, as shown in FIG. 6, the worker folds the correction piece 38 at the boundary located on the same straight line as the insertion auxiliary fold line 37, and pushes it in the direction of pressing it against the first lower flap 22D (see the solid arrow in FIG. 6). In the second lower flap 23D, a punching hole 39 is opened at the mark where the correction piece 38 was punched. In addition, the pushed-in correction piece 38 is located one step lower than the surface of the second lower flap 23D (pressing part 36), and the correction piece 38 contacts the edge of the punching hole 39 along the contour of the cutting line 38A with a frictional force (see the dashed arrow in FIG. 6) due to its own restoring force (elastic force in the opposite direction to the pushing direction). In other words, the outer edge of the correction piece 38 slides against the inner edge of the punching hole 39. As the straightening piece 38 is pressed in and a frictional force acts on the edge of the punch hole 39, a straightening force is generated that presses the base portion of the straightening piece 38 (near the insertion auxiliary fold line 37) against the first bottom flap 22D (see the white arrow in FIG. 6). This straightening force relatively presses the insertion auxiliary fold line 37, so that the fold at the insertion auxiliary fold line 37 of the second bottom flap 23D is straightened.

[0038] As described above, the lower opening of the peripheral wall W is closed by the lid portion 10D (first lower flap 22D, second lower flap 23D). That is, the bottom of the packaging box 1 is formed. The worker places a product (not shown) inside the peripheral wall W (places the product on the bottom).

[0039] The worker closes the upper opening of the peripheral wall W with the lid part 10U (first upper flap 22U, second upper flap 23U) in the same manner as the lid part 10D (see FIG. 1). Note that the procedure for closing the upper opening of the peripheral wall W with the lid part 10U is similar to the procedure for closing the lower opening with the lid part 10D, and therefore the explanation thereof will be omitted.

[0040] This completes the assembly of the packaging box 1 (see FIG. 1). The packaging box 1 is sealed without using adhesive tape, glue, etc. To open (or disassemble) the packaging box 1, the above assembly steps can be reversed.

[0041] According to the packaging box 1 according to the first embodiment described above, the pushed-in correction piece 38 is caught on the edge of the punch hole 39 by the elastic force, and a correction force is generated to return the second flap 23 to a flat state, so that the fold at the insertion auxiliary fold line 37 of the second flap 23 can be corrected. This makes it possible to suppress the second flap 23 from floating up due to the fold. As a result, the insertion piece 35 is prevented from being pulled out due to vibration during transportation, etc., and unintentional opening can be prevented. In addition, when multiple packaging boxes 1 are stacked, the raised second flap 23 does not get in the way, and the boxes can be stacked appropriately.

[0042] Furthermore, since the inserted portion 30 (push-in piece 31) has a cut-and-raised structure, the insertion piece 35 can be sandwiched between the push-in piece 31 and the piece pressing portion 34. This makes it possible to further strengthen the prevention of the insertion piece 35 from falling out. Furthermore, since the portion that the tip of the insertion piece 35 abuts against when inserting the insertion piece 35 is the push-in piece 31, the tip of the insertion piece 35 does not come into direct contact with the internal merchandise, and damage to the merchandise can be minimized.

[0043] Furthermore, according to the packaging box 1 according to the first embodiment, the correcting piece 38 is formed wide in the insertion direction, which prevents the correcting piece 38 from being pulled out from the hole 39. The pushed-in correcting piece 38 also becomes an obstacle, which increases the resistance to the insertion piece 35 being pulled out. This effectively prevents unintentional opening.

[0044] Furthermore, according to the packaging box 1 of the first embodiment, a protrusion 35A is provided on the insertion piece 35, and the inclined edge 33B of the insertion hole 33 is formed so as to intersect with the protrusion 35A (inserted into the insertion hole 33). Therefore, even if a force is applied to the insertion piece 35 in the pulling-out direction, the protrusion 35A interferes with the inclined edge 33B, thereby preventing the insertion piece 35 from coming out.

[0045] [Variations] In the packaging box 1 according to the first embodiment, the straightening piece 38 is in close contact with the edge of the punch hole 39 with almost no gap, so that it is difficult to pull out the pushed-in straightening piece 38. Therefore, as a modified example, as shown in FIG. 8, the second flap 23 may be formed with a release opening 27 for pulling out the pushed-in straightening piece 38. The release opening 27 is formed at a position adjacent to the straightening piece 38 of the second flap 23. The release opening 27 is a cutout with a substantially semicircular shape that is large enough for an operator's finger to enter. According to this configuration, an operator can insert his / her finger into the release opening 27 to pull out the pushed-in straightening piece 38. The release opening 27 may be formed in the straightening piece 38, or may be formed in both the second flap 23 and the straightening piece 38 (not shown). The shape of the release opening 27 is not limited to a semicircular shape and may be freely changed.

[0046] In the packaging box 1 according to the first embodiment (including modified examples, the same applies below), two pairs of protrusions 35A are formed on the two pairs of insertion pieces 35, but the present invention is not limited to this. It is sufficient that a pair of protrusions 35A is formed on at least one pair of the two pairs of insertion pieces 35. In this case, the inclined edge 33B does not need to be formed on all of the insertion holes 33, but only needs to be formed on the insertion holes 33 corresponding to the insertion pieces 35 having the protrusions 35A. In addition, the protrusions 35A of the insertion pieces 35 and the inclined edge 33B of the insertion holes 33 may be omitted (not shown). Furthermore, the insertion holes 33 are formed in a mountain shape, but may be formed in a square shape, for example (not shown). In addition, the push-in pieces 31 (pushing fold lines 31A) may be omitted, and the insertion holes 33 may be open from the beginning (not shown).

[0047] In addition, in the packaging box 1 according to the first embodiment, the pair of first lower flaps 22D (the pair of first upper flaps 22U) are configured to overlap at the stepped portion 25 on the leading end side, but the present invention is not limited to this. The pair of first lower flaps 22D (the pair of first upper flaps 22U) may be configured to omit the stepped portion 25 and have leading ends butted together, or the leading ends may be spaced apart from each other (not shown).

[0048] In addition, in the packaging box 1 according to the first embodiment, the lids 10U, 10D are provided at the upper and lower ends of the peripheral wall W, but the present invention is not limited to this. For example, only the lower opening of the peripheral wall W may be closed by the lid 10D, and the upper opening of the peripheral wall W may be open. In other words, it is sufficient that the lid is connected to at least one of the axial ends of the peripheral wall W.

[0049] [Second embodiment] Next, a packaging box 2 according to a second embodiment will be described with reference to Fig. 9 to Fig. 11. Fig. 9 is a perspective view showing the packaging box 2. Fig. 10 is a plan view showing a blank 6 of the packaging box 2. Fig. 11 is a perspective view explaining the process of assembling the packaging box 2. In the following explanation, the same reference numerals are used for the same or corresponding configurations as those of the packaging box 1 according to the first embodiment, and explanations of the same or corresponding components will be omitted.

[0050] 9 and 10, the packaging box 2 according to the second embodiment includes a peripheral wall W and lids 11U and 11D that close the openings at the upper and lower ends of the peripheral wall W. The lid 11D is a so-called one-touch bottom. The lid 11U has a first flap 43 and a second flap 44 that are connected to a pair of first side walls 20 that face each other in the front-to-rear direction (first direction) of the peripheral wall W.

[0051] [blank] 10, the blank 6 of the packaging box 2 includes a pair of first side walls 20, a pair of second side walls 21, a pair of first bottom walls 40, a pair of second bottom walls 41, a pair of inner flaps 42, a first flap 43, and a second flap 44. Note that since a pair of portions have substantially the same shape, hereinafter, only one portion will be described unless otherwise specified.

[0052] <First bottom wall> The pair of first bottom walls 40 are connected to one end (lower end) of the first side wall 20 in the step direction via the second fold line L2. The first bottom wall 40 is formed in a generally rectangular shape, and its dimension in the step direction (extension dimension) is set to be slightly longer than half the dimension in the flow direction of the second side wall 21. An interlocking recess 40A is cut out in a generally V-shape at the tip side of the first bottom wall 40. A hook portion 40B is connected to one side of the interlocking recess 40A via an interlocking fold line 40C. An inclined fold line 40E is formed obliquely from the interlocking recess 40A toward the base end corner of the first bottom wall 40 at the other side in the flow direction (the side of the second bottom wall 41). A generally triangular bottom adhesive portion 40D is defined in the corner region of the first bottom wall 40 by the inclined fold line 40E.

[0053] <Second bottom wall> The pair of second bottom walls 41 are connected to one end (lower end) in the step direction of the second side wall 21 via the second folding line L2. The second bottom wall 41 is formed in a generally trapezoidal shape that gradually narrows from the base end to the tip. The dimension (extension dimension) of the second bottom wall 41 in the step direction is set to be slightly shorter than the extension dimension of the first bottom wall 40.

[0054] The interlocking fold line 40C is a general-purpose crease, and the inclined fold line 40E is a reverse crease that is crushed in the thickness direction from the side of the front liner 9B. The reverse crease has the function of folding (reverse folding) the cardboard sheet so that the front liner 9B faces inward. The interlocking fold line 40C and the inclined fold line 40E are not limited to general-purpose creases or reverse creases, and may be any lines for folding the cardboard sheet, such as perforation lines or lead creases.

[0055] <Inner flap> The pair of inner flaps 42 are connected to the other end (upper end) in the step direction of the second side wall 21 via the third fold line L3. The inner flap 42 is formed in a substantially rectangular shape, and the dimension in the step direction (extension dimension) is set to be slightly shorter than half the dimension in the flow direction of the first side wall 20.

[0056] <First flap, second flap> The first flap 43 is connected to the other end (upper end) in the step direction of one of the first side walls 20 via the third fold line L3. The first flap 43 is formed in a substantially rectangular shape, and its dimension in the step direction (extension dimension) is substantially the same as the extension dimension of the inner flap 42. The second flap 44 is connected to the other end (upper end) in the step direction of the other first side wall 20 via the third fold line L3. The second flap 44 is formed in a substantially rectangular shape, and its maximum dimension in the step direction (extension dimension) is substantially the same as the extension dimension of the inner flap 42. Step-flattened portions 45 are formed on both sides in the flow direction of the tip sides (free ends) of the first flap 43 and the second flap 44 (see the hatched portions in FIG. 10).

[0057] [Lock structure] The upper cover portion 11U (first flap 43, second flap 44) is provided with a lock structure 46 for keeping the upper opening of the peripheral wall W closed. The lock structure 46 has an insertion portion 50, an insertion piece 51, an insertion assist fold line 37, and three correction pieces 52.

[0058] <Inserted part> The insertion portion 50 is a slit-like hole formed at the tip side in the step direction of the first flap 43. The insertion portion 50 opens in the middle part of the first flap 43 in the flow direction (between the pair of step-flattened parts 45). To be precise, the insertion portion 50 has an elongated insertion hole 50A in the flow direction, and a pair of insertion cuts 50B cut outward from both ends of the insertion hole 50A in the flow direction. The center part of the insertion hole 50A in the flow direction is formed in a substantially fan-like (arc-like) shape.

[0059] <Insert piece> The insertion piece 51 is formed on the tip side (free end side) in the step direction of the second flap 44. The insertion piece 51 is provided to protrude from the middle part (between the pair of step flattened parts 45) in the flow direction of the second flap 44 toward the tip side. The insertion piece 51 is formed in a substantially rectangular shape with the corners on the tip side chamfered. A pair of cuts 51A are cut in the base end part of the insertion piece 51 in a direction approaching each other.

[0060] <Insertion auxiliary folding line, correction piece> The insertion auxiliary fold line 37 is formed parallel to the flow direction in the middle of the second flap 44 in the step direction, except for the three straightening pieces 52. The three straightening pieces 52 are provided at approximately equal intervals at approximately the center and both sides of the insertion auxiliary fold line 37 in the flow direction. The straightening piece 52 in the center in the flow direction is divided by a cutting line 52A formed to protrude from the insertion auxiliary fold line 37 toward the tip side of the second flap 44. The two straightening pieces 52 on both sides in the flow direction are divided by cutting lines 52A formed to protrude from the insertion auxiliary fold line 37 toward the base end side of the second flap 44. The three straightening pieces 52 (cutting lines 52A) are each formed in an approximately rectangular shape. When the three straightening pieces 52 are pressed in, three punch holes 53 are opened in the second flap 44.

[0061] [Assembly of packaging boxes] Next, the assembly process of the packaging box 2 will be described with reference to Fig. 9 and Fig. 11. Here, as an example, a case where an operator manually assembles the packaging box 2 will be described. The initial state of the packaging box 2 is folded twice (not shown) like the initial state of the packaging box 1 according to the first embodiment. The first bottom wall 40 and the second bottom wall 41 are folded back inward along the third fold line L3, and the bottom adhesive portion 40D of the first bottom wall 40 is folded back at the inclined fold line 40E and adhered to the front liner 9B of the second bottom wall 41.

[0062] The worker bends the pair of first side walls 20 and the pair of second side walls 21 at a substantially right angle to form the peripheral wall W. In conjunction with the formation of the peripheral wall W, the folded-back first bottom wall 40 and the second bottom wall 41 are pushed out until they are substantially parallel to each other while flattening the reverse-folded bottom adhesive portion 40D (not shown). The hook portions 40B of the pair of first bottom walls 40 enter the opposing interlocking recesses 40A while bending at the interlocking fold lines 40C, and are interlocked with each other (not shown).

[0063] As a result of the above, the lower opening of the peripheral wall W is closed by the lid portion 11D (first bottom wall 40, second bottom wall 41). The worker stores the product inside the peripheral wall W (places the product on the bottom).

[0064] 11, the worker closes the upper opening of the peripheral wall W with the lid portion 11U (the first flap 43 and the second flap 44). Specifically, the worker folds the pair of inner flaps 42 inwardly along the third fold line L3, and then folds the first flap 43 inwardly along the third fold line L3 to overlap the first flap 43 on the surface of the pair of inner flaps 42.

[0065] Next, the worker fixes the second flap 44 to the first flap 43 using the lock structure 46. Specifically, the worker folds the second flap 44 at the insertion auxiliary fold line 37, and aligns the tip of the insertion piece 51 with the insertion receiving portion 50 opened in the first flap 43. The worker inserts the insertion piece 51 into the insertion receiving portion 50 while folding the second flap 44 at the third fold line L3 and returning the second flap 44, which has been mountain-folded at the insertion auxiliary fold line 37, to a flat state. The insertion piece 51 slides into the back side of the first flap 43, and the pair of step-flattened portions 45 of the second flap 44 overlap the surface of the step-flattened portion 45 of the first flap 43. The insertion piece 51 is held by the pair of insertion cuts 50B of the insertion receiving portion 50, and is not easily pulled out of the insertion hole 50A.

[0066] Next, as shown in Fig. 9, the worker pushes the three straightening pieces 52 inward to open the three punch holes 53. The pushed-in straightening pieces 52 come into contact with the edge of the punch hole 53 with a frictional force due to their own restoring force. As each straightening piece 52 is pushed in and a frictional force acts on the edge of the punch hole 53, a straightening force is generated that presses the root portion of each straightening piece 52 against the first flap 43. The insertion auxiliary fold line 37 is pushed in by this straightening force, and the fold crease at the insertion auxiliary fold line 37 of the second flap 44 is straightened.

[0067] In this manner, the upper opening of the peripheral wall W is closed, and the assembly of the packaging box 2 is completed. The packaging box 2 is sealed without using adhesive tape, glue, or the like. When the packaging box 2 is used for mail order purposes, a shipping slip may be attached so that it covers both the first flap 43 and the second flap 44. To open (or disassemble) the packaging box 2, the assembly steps described above are carried out in reverse.

[0068] The packaging box 2 according to the second embodiment described above can provide the same advantages as the packaging box 1 according to the first embodiment, such as preventing the second flap 44 from floating up due to creases.

[0069] In the packaging box 2 according to the second embodiment, the stepped portions 45 are formed in the first flap 43 and the second flap 44, but the stepped portions 45 may be omitted.

[0070] [Third embodiment] Next, a packaging box 3 according to a third embodiment will be described with reference to Fig. 12 and Fig. 13. Fig. 12 is a perspective view showing the packaging box 3. Fig. 13 is a plan view showing a blank 7 of the packaging box 3. In the following description, the same reference numerals are used for configurations that are the same as or correspond to those of the packaging box 1 according to the first embodiment, and descriptions of the same or corresponding components will be omitted.

[0071] As shown in Fig. 12 and Fig. 13, the packaging box 3 according to the third embodiment is an approximate A-type box that is sealed by closing the openings at the upper and lower ends of the peripheral wall W with the lids 12U and 12D. The lid 12D has a pair of lower inner flaps 60 connected to a pair of second side walls 21 that face each other in the left-right direction of the peripheral wall W, and a pair of lower outer flaps 61 connected to a pair of first side walls 20 that face each other in the front-rear direction of the peripheral wall W. The lid 12U has a first flap 62 and a third flap 64 connected to a pair of first side walls 20 that face each other in the front-rear direction (first direction) of the peripheral wall W. The lid 12U also has a second flap 63 and a fourth flap 65 connected to a pair of second side walls 21 that face each other in the left-right direction (second direction) of the peripheral wall W.

[0072] [blank] 13, the blank 7 of the packaging box 3 includes a pair of first side walls 20, a pair of second side walls 21, a pair of lower inner flaps 60, a pair of lower outer flaps 61, and first to fourth flaps 62 to 65. Note that since a pair of portions have substantially the same shape, hereinafter, only one portion will be described unless otherwise specified.

[0073] <Lower inner flap, lower outer flap> The pair of lower inner flaps 60 are connected to one end (lower end) in the step direction of the first side wall 20 via the second fold line L2. The pair of lower outer flaps 61 are connected to one end in the step direction of the second side wall 21 via the second fold line L2. The lower inner flaps 60 and the lower outer flaps 61 are formed in a substantially rectangular shape, and their dimension in the step direction (extension dimension) is set to approximately half the dimension in the flow direction of the second side wall 21.

[0074] <1st to 4th flaps> The first flap 62 and the third flap 64 are connected to the other end (upper end) in the step direction of the first side wall 20 via the third fold line L3. The second flap 63 and the fourth flap 65 are connected to the other end (upper end) in the step direction of the second side wall 21 via the third fold line L3. The first to fourth flaps 62 to 65 are formed in a substantially rectangular shape, and their dimensions in the step direction (extension dimensions) are substantially the same as the extension dimensions of the lower inner flap 60, etc.

[0075] [Lock structure] The upper cover portion 12U (first to fourth flaps 62 to 65) is provided with a lock structure 66 for keeping the upper opening of the peripheral wall W closed. The lock structure 66 has an insertion portion 70, an insertion piece 71, an insertion assist fold line 37, and a correction piece 38.

[0076] <Inserted part> The inserted portion 70 is a notch extending from the tip to the base end in the step direction of the first flap 62. The inserted portion 70 is cut out in a substantially triangular shape on the side of the second flap 63 adjacent to the first flap 62. Near the inserted portion 70 of the first flap 62, a substantially semicircular finger hole 70A is cut out.

[0077] <Insert piece> The insertion piece 71 is formed at the tip end of the second flap 63 in the step direction. In detail, a slit 72 is cut from the tip end to the base end of the second flap 63, and a pressing portion 73 is provided on the first flap 62 side of the slit 72. The insertion piece 71 is provided on the opposite side of the pressing portion 73 with the slit 72 in between. The insertion piece 71 is formed by a part of the second flap 63 adjacent to the slit 72.

[0078] <Insertion auxiliary folding line, correction piece> The insertion auxiliary fold line 37 is formed parallel to the flow direction in the intermediate portion in the step direction of the second flap 63, except for the correction piece 38. The correction piece 38 is formed so as to protrude from the insertion auxiliary fold line 37 toward the tip side of the second flap 63 at approximately the center of the insertion auxiliary fold line 37 in the flow direction.

[0079] [Assembly of packaging boxes] Next, the assembly process of the packaging box 3 will be described with reference to Fig. 12. Here, as an example, a case where an operator manually assembles the packaging box 3 will be described. Note that the initial state of the packaging box 3 is folded twice (not shown), similar to the initial state of the packaging box 1 according to the first embodiment.

[0080] The worker folds the pair of first side walls 20 and the pair of second side walls 21 at a substantially right angle to form the peripheral wall W. Next, although not shown, the worker folds the pair of lower inner flaps 60 inward at the second fold line L2, and then folds the pair of lower outer flaps 61 inward at the second fold line L2. The pair of lower outer flaps 61 are overlapped on the surfaces of the pair of lower inner flaps 60, and the tips of the pair of lower outer flaps 61 are butted against each other. The worker attaches an adhesive tape (not shown) along the butted portion of the pair of lower outer flaps 61. Note that instead of the adhesive tape, an adhesive may be used to adhere the pair of lower outer flaps 61 to the pair of lower inner flaps 60.

[0081] As described above, the lower opening of the peripheral wall W is closed by the lid portion 12D (the lower inner flap 60, the lower outer flap 61), forming the bottom of the packaging box 3 (not shown). The worker stores the product inside the peripheral wall W (places the product on the bottom).

[0082] Next, the worker closes the upper opening of the peripheral wall W with the lid portion 12U (the first to fourth flaps 62 to 65). Specifically, the worker folds the first flap 62, the fourth flap 65, the third flap 64 and the second flap 63 in this order toward the inside of the peripheral wall W, and uses the lock structure 66 to fix the second flap 63 to the first flap 62.

[0083] Specifically, the worker folds the second flap 63 at the insertion auxiliary fold line 37, and aligns the tip of the insertion piece 71 with the insertion receiving portion 70 cut out in the first flap 62. The worker inserts his / her finger into the finger hole 70A to lift a part of the first flap 62, and while folding the second flap 63 at the third fold line L3 and returning the second flap 63, which has been mountain-folded at the insertion auxiliary fold line 37, to a flat state, inserts the insertion piece 71 into the insertion receiving portion 70. The insertion piece 71 slides into the back side of the first flap 62, and the second flap 63 overlaps with the surfaces (outer surfaces) of the adjacent first flap 62 and third flap 64 at the portion excluding the insertion piece 71. The insertion piece 71 and the pressing portion 73 hold the first flap 62, so that the insertion piece 71 cannot be easily pulled out of the insertion receiving portion 70.

[0084] Next, the worker pushes in the correction piece 38, so that the fold at the insertion auxiliary fold line 37 of the second flap 63 is corrected.

[0085] In this manner, the upper opening of the peripheral wall W is closed, completing the assembly of the packaging box 3. To open (or disassemble) the packaging box 3, the above-described assembly steps can be carried out in reverse order.

[0086] The packaging box 3 according to the third embodiment described above can achieve the same effects as the packaging box 1 according to the first embodiment, such as preventing the second flap 63 from floating up due to folds.

[0087] In the packaging box 1 according to the first embodiment, the locking structures 26U, 26D are provided on both the upper and lower sides of the peripheral wall W, and in the packaging boxes 2, 3 according to the second and third embodiments, the locking structures 46, 66 are provided only above the peripheral wall W, but the present invention is not limited to this. It is sufficient that the locking structures are provided on at least one of the upper and lower sides of the peripheral wall W.

[0088] In addition, in the packaging boxes 1 and 3 according to the first and third embodiments, one straightening piece 38 is provided protruding from the insertion auxiliary fold line 37 toward only the tip side of the second flaps 23 and 63, and in the packaging box 2 according to the second embodiment, three straightening pieces 52 are provided protruding from the insertion auxiliary fold line 37 toward both the tip side and the base side of the second flap 44, but the present invention is not limited to this. It is sufficient that the straightening piece is provided protruding from the insertion auxiliary fold line 37 toward at least one of the tip side and the base side of the second flaps 23, 44, and 63.

[0089] In addition, in the packaging boxes 1 to 3 according to the first to third embodiments, the straightening pieces 38, 52 are formed in a substantially trapezoidal or rectangular shape, but the present invention is not limited thereto. For example, the shape of the straightening pieces 38, 52 may be any shape, such as a triangular shape, a polygonal shape other than a quadrangle, a semicircular shape, or a shape that combines these (not shown). In addition, the cutting lines 38A, 52A that divide the straightening pieces 38, 52 may be cut with a straight blade, or may be cut, for example, in a wavy shape in order to increase the frictional force with the straightening pieces 38, 52 (not shown).

[0090] In addition, in the packaging boxes 1 to 3 according to the first to third embodiments, the insertion auxiliary fold line 37 is a general-purpose crease, but it is not limited to this and may be any line for folding a cardboard sheet, such as a perforation line or a lead crease (not shown). In addition, the insertion auxiliary fold line 37 is formed approximately parallel to the second and third fold lines L2, L3, but it is not limited to this and may be formed at an angle to the second and third fold lines L2, L3 (not shown).

[0091] In addition, the packaging boxes 1 to 3 according to the first to third embodiments are formed from a double-sided corrugated cardboard sheet made of paper, but the present invention is not limited to this. The packaging boxes 1 and 2 may be formed from single-sided corrugated cardboard, double-sided corrugated cardboard, triple-double-sided corrugated cardboard, etc., or may be formed from cardboard, a resin plate (sheet), etc.

[0092] The above embodiment is merely an example of the packaging box of the present invention, and the technical scope of the present invention is not limited to the above embodiment. The technical scope of the present invention is not limited to the above embodiment. The present invention may be modified, substituted, or altered in various ways without departing from the spirit of the technical idea, and the claims include all embodiments that may be included within the scope of the technical idea. [Explanation of symbols]

[0093] 1,2,3 Packaging box W Peripheral wall 10U,10D,11U,12U Lid 20 First side wall 21 Second side wall 22D 1st lower flap (1st flap) 22U 1st upper flap (1st flap) 23D 2nd lower flap (2nd flap) 23U 2nd upper flap (2nd flap) 27 Release opening 30,50,70 Inserted part 33 Insertion hole 33B Sloped edge 35,51,71 Insert 35A protrusion 37 Insertion auxiliary fold line 38,52 Orthodontic piece 38A,52A cutting line 39,53 Hole 43,62 First flap 44,63 Second flap 64 3rd flap 65 4th flap 70A pointing hole 72 Slit 73 Pressing part

Claims

1. A peripheral wall (W) formed in a cylindrical shape by alternately connecting a pair of first side walls (20) and a pair of second side walls (21); a cover portion (12U) connected to at least one of both axial ends of the peripheral wall and closing an opening of the peripheral wall; The lid portion is a first flap (62) and a third flap (64) connected to one end of the pair of first side walls in the axial direction and folded inwardly of the peripheral wall; a second flap (63) and a fourth flap (65) connected to one end of the pair of second side walls in the axial direction and folded inwardly of the peripheral wall, The first flap has an insertion portion (70) formed in a state penetrating in a thickness direction, The second flap is An insertion piece (71) formed on the tip side and inserted into the inserted portion; An insertion auxiliary fold line (37) is formed on the base end side of the insertion piece and causes the second flap to fold in a mountain shape when the insertion piece is inserted into the insertion portion; and a correction piece (38) partitioned by a cutting line (38A) formed so as to protrude from the insertion auxiliary folding line toward at least one of the tip side and the base side, the insertion portion is a notch extending from a tip end of the first flap toward a base end thereof, The insertion piece is formed as a part of the second flap adjacent to a slit (72) cut from the tip end to the base end of the second flap, a first flap, a fourth flap, a third flap, and a second flap are folded inwardly of the peripheral wall in this order, and the insertion piece is inserted into the receiving portion, and the second flap overlaps with the outer surfaces of the adjacent first and third flaps at a portion excluding the insertion piece, and the straightening piece is pressed in and comes into frictional contact with the edge of a punch hole (39) that follows the contour of the cutting line due to its own restoring force, generating a straightening force that straightens the fold at the insertion auxiliary fold line of the second flap.

2. The packaging box according to claim 1, characterized in that a finger hole (70A) is cut out at the tip of the first flap and near the insertion portion, through which an operator can insert his or her finger to lift a portion of the first flap when inserting the insertion piece into the insertion portion.

3. The second flap is provided with a pressing portion (73) on the first flap side relative to the slit, and the insertion piece is provided on the opposite side of the pressing portion across the slit, The packaging box according to claim 1 or 2, characterized in that when the insertion piece is inserted into the receiving portion, the pressing portion overlaps with the outer surface of a portion of the first flap, clamping the first flap between the insertion piece and the pressing portion.

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