Packing box

Abstract

To provide a packaging box that facilitates breakage along a break guide line and has good opening workability.SOLUTION: A packaging box has a body part 5 having a pair of front and rear side plates 11 and 12 and a pair of right and left end plates 13 and 14, a bottom plate 30, and a top plate 20. The top plate 20 includes a pair of right and left inner flaps 22 and 22 and a pair of front and rear outer flaps 21 and 21. The packaging box also has: a front outer tear support ruled line L25 provided on the front outer flap 21, extending in a right-left direction, and curved in an arc shape convex toward an edge of the front plate 11; a rear outer tear support ruled line L25 provided on the rear outer flap 21, extending in the right-left direction, and curved in an arc shape convex toward an edge of the rear plate 12; and inner tear support ruled lines L26 and L26 provided on both inner flaps 22 and 22 and curved in an arc shape along the front and rear outer tear support ruled lines L25 and L25.SELECTED DRAWING: Figure 1

Description

[Technical Field]

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

[0002] BACKGROUND ART Conventionally, packaging boxes are known that are used as transport boxes when transporting products and also used when displaying products in stores (see, for example, Patent Document 1). In the packaging box of Patent Document 1, the top plate can be separated by utilizing folding assist lines formed on the inner and outer flaps. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-210454 Summary of the Invention [Problem to be solved by the invention]

[0004] In the conventional packaging boxes described above, the top plate can be opened using the folding guide line, but because the shapes of the folding guide line differ between the inner flap and the outer flap, there is a problem that the breaking progress may deviate from the breaking guide line when opening, making the opening operation difficult.

[0005] SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems and to provide a packaging box that is easy to break along the break guide line and has good opening properties. [Means for solving the problem]

[0006] In order to solve the above problems, the packaging box of the present invention has a body portion having a pair of front and rear side plates and a pair of left and right end plates, a bottom plate closing a lower opening of the body portion, and a top plate closing an upper opening of the body portion. At least one of the bottom plate and the top plate has a pair of left and right inner flaps connected to the edges of the both end plates via at least one of end plate break guide lines and creases, and a pair of front and rear outer flaps connected to the edges of the both side plates via the side plate break guide lines and overlapped on the outer surfaces of the inner flaps. Furthermore, the packaging box of the present invention is provided with: a front outer break support crease provided on the front outer flap, extending in the left-right direction and curved in an arc that convexly forms toward the edge of the front side panel; a rear outer break support crease provided on the rear outer flap, extending in the left-right direction and curved in an arc that convexly forms toward the edge of the rear side panel; and inner break support creases provided on both inner flaps, curved in an arc that follows the front outer break support crease and the rear outer break support crease. At least one of the pair of left and right end plates has a tear-starting portion that serves as a starting point for opening, and a tear-guiding line for opening that is connected to the tear-starting portion. The inner tear-support crease passes through the edge of the end plate and extends to the tear-starting portion.

[0007] In the packaging box of the present invention, when the end plate break guide lines are cut open and, for example, the top plate is pulled up, a break progresses from at least one of the end plate break guide lines and the crease line to the side plate break guide lines of both side plates. This causes both outer flaps to bend at the front and rear outer break support lines, and both inner flaps to bend at the corresponding inner break support lines along these lines, causing both outer and inner flaps to bend in the same direction. This ensures that the break progresses along the side plate break guide lines of both side plates and prevents deviation from the side plate break guide lines. Furthermore, because the break progresses along the side plate break guide lines of both side plates, the break also progresses smoothly along the end plate break guide lines on the opposite side of the side plate break guide lines, allowing the top plate to be smoothly separated from the body. This makes it easy to open the top plate. Furthermore, when the tearing section is pulled up with the fingers starting from the tear initiation section, the end plate bends at the inner break support crease extending along the tearing section, allowing the tearing section to be smoothly opened along this inner break support crease. When the tearing section is opened, the break progresses from the tear guide line for opening to the side plate break guide lines of both side plates, and then the break progresses smoothly from the side plate break guide lines of both side walls to the opposite end plate break guide line and the tear guide line for opening. This allows the top plate to be more efficiently separated from the body section.

[0008] The packaging box of the present invention includes a body having a pair of front and rear side panels and a pair of left and right end panels, a bottom panel closing a lower opening of the body, and a top panel closing an upper opening of the body. At least one of the bottom panel and the top panel includes a pair of left and right inner flaps connected to the edges of the end panels via at least one of end panel break guide lines and creases, a pair of left and right inner flaps connected via the end panel break guide lines, and a pair of front and rear outer flaps connected to the edges of the side panels via the side panel break guide lines and overlapping the outer surfaces of the inner flaps. The packaging box of the present invention further includes an outer break support crease provided on the pair of front and rear outer flaps and extending in the left-right direction, and an inner break support crease provided on the pair of left and right inner flaps and extending in the left-right direction, the outer break support crease and the inner break support crease overlapping in the vertical direction. At least one of the pair of left and right end plates has a tear-starting portion that serves as a starting point for opening, and a tear-guiding line for opening that is connected to the tear-starting portion. The inner tear-support crease passes through the edge of the end plate and extends to the tear-starting portion.

[0009] In the packaging box of the present invention, when the end plate break guide lines are cut open and, for example, the top plate is pulled up, a break progresses from at least one of the end plate break guide lines and the crease line to the side plate break guide lines of both side plates. This causes both outer flaps to bend at the outer break support lines, and both inner flaps to bend at the overlapping inner break support lines, causing both outer and inner flaps to bend in the same direction. This ensures that the break progresses along the side plate break guide lines of both side plates and prevents deviation from the side plate break guide lines. Furthermore, because the break progresses along the side plate break guide lines of both side plates, the break also progresses smoothly at the end plate break guide lines on the opposite side of the side plate break guide lines, allowing the top plate to be smoothly separated from the body. This makes it easy to open the top plate. Furthermore, when the tearing section is pulled up with the fingers starting from the tear initiation section, the end plate bends at the inner break support crease extending along the tearing section, allowing the tearing section to be smoothly opened along this inner break support crease. When the tearing section is opened, the break progresses from the tear guide line for opening to the side plate break guide lines of both side plates, and then the break progresses smoothly from the side plate break guide lines of both side walls to the opposite end plate break guide line and the tear guide line for opening. This allows the top plate to be more efficiently separated from the body section. [Effects of the Invention]

[0012] The packaging box of the present invention is easy to break along the break guide line, and is easy to open. [Brief explanation of the drawings]

[0013] [Figure 1]1 is a perspective view showing a packaging box according to a first embodiment of the present invention. [Figure 2] 1 is a diagram showing a blank sheet for a packaging box according to a first embodiment of the present invention. [Figure 3] 3 is an enlarged view of the area around the opening portion of the left end plate of the blank sheet for the packaging box according to the first embodiment of the present invention, viewed from the inside. FIG. [Figure 4] 1 is a perspective view showing a state when the packaging box according to the first embodiment of the present invention is opened. [Figure 5] 10 is an enlarged view of the area around the opening portion of the left end plate of a blank sheet for a packaging box according to a modified example, viewed from the inside. FIG. [Figure 6] 10 is an enlarged view of the area around the opening portion of the left end plate of a blank sheet for a packaging box according to a second embodiment of the present invention, viewed from the inside. FIG. [Figure 7] FIG. 10 is an enlarged view of the area around the opening portion of the left end plate, viewed from the inside, of a blank sheet for a packaging box according to a modified example of the second embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0014] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail with reference to the accompanying drawings. In the following description, the front, back, left, and right directions are set for the convenience of describing the packaging box of each embodiment, and do not limit the configuration of the packaging box of the present invention. Note that in each embodiment, the same parts are given the same reference numerals, and detailed descriptions will be omitted.

[0015] (First embodiment) As shown in Figures 1 and 2, the packaging box 1 of this embodiment is an A-type box and has a rectangular parallelepiped shape with a left-right length greater than a front-to-back length. The packaging box 1 includes a bottom plate 30, side plates 11 and 12 connected to the front and rear edges of the bottom plate 30, end plates 13 and 14 connected to the left and right edges of the bottom plate 30, and a top plate 20 facing the bottom plate 30. The front and rear side plates 11 and 12 and the left and right end plates 13 and 14 form a rectangular cylindrical body 5, and the top plate 20 closes an upper opening of the body 5. The packaging box 1 is used as a shipping box for transporting products, and, as described below, can also be used as a box for displaying products in stores by opening the top plate 20.

[0016] The packaging box 1 is formed by mountain or valley folding a blank sheet S1 cut out from a single sheet of cardboard at each crease, as shown in Fig. 2. The blank sheet S1 shown in Fig. 2 is arranged so that the inner side is visible. Each crease (fold line) on the blank sheet S1 is a linear groove (pressed crease) formed by pressing the surface of the blank sheet S1. Note that notches (half-cut lines, etc.) may be formed on the crease lines, which makes it easier to fold the blank sheet S1 at the crease lines.

[0017] The side plates 11, 12 (front side plate 11, rear side plate 12) and end plates 13, 14 (left end plate 13, right end plate 14) that constitute the body 5 are each rectangular plates. A left end plate 13 is connected to the left edge of the front plate 11 via a crease. A right end plate 14 is connected to the right edge of the front plate 11 via a crease. A rear plate 12 is connected to the rear edge of the left end plate 13 via a crease. A strip-shaped joint piece 15 is connected to the right edge of the rear plate 12 via a crease. The joint piece 15 is bonded to the inner surface of the right end plate 14 by an adhesive such as hot melt.

[0018] Then, when the blank sheet S1 (see FIG. 2) is folded along each of the lines, the front plate 11, rear plate 12, left end plate 13, and right end plate 14 form a rectangular cylindrical body portion 5.

[0019] The top plate 20 includes a pair of front and rear upper outer flaps 21, 21 connected to the upper edges of the front plate 11 and the rear plate 12, and a pair of left and right upper inner flaps 22, 22 connected to the upper edges of the left end plate 13 and the right end plate 14. The upper outer flaps 21, 21 are overlapped on the upper surfaces (outer surfaces) of the left and right upper inner flaps 22, 22. The leading ends of the upper outer flaps 21, 21 butt together in the center in the front-to-rear direction. In this embodiment, the top plate 20 is sealed by applying adhesive tape T from the left end plate 13, through the butted portion between the upper outer flaps 21, 21, and to the right end plate 14.

[0020] The bottom plate 30 includes a pair of front and rear lower outer flaps 31, 31 connected to the lower edges of the front plate 11 and the rear plate 12, and a pair of left and right lower inner flaps 32, 32 connected to the lower edges of the left end plate 13 and the right end plate 14. The pair of front and rear lower outer flaps 31, 31 are superimposed on the outer surfaces of the pair of left and right lower inner flaps 32, 32 and are adhered to the pair of left and right lower inner flaps 32, 32 with an adhesive such as hot melt. As with the top plate 20, the bottom plate 30 may be sealed by applying adhesive tape T.

[0021] Next, the top plate 20 will be described in detail. The front upper outer flap 21 constituting the top plate 20 is a rectangular flat plate that extends rearward from the upper edge of the front side plate 11. The front upper outer flap 21 closes the front half of the upper opening of the body 5. The rear upper outer flap 21 is a rectangular flat plate that extends forward from the upper edge of the rear panel 12. The rear upper outer flap 21 closes the rear half of the upper opening of the body 5.

[0022] The left upper outer flap 21 is connected to the upper edge of the front plate 11 via a front plate breaking guide line L21. The front plate breaking guide line L21 is for separating the front upper outer flap 21 from the front plate 11, and is formed along the entire upper edge of the front plate 11 (the front edge of the front upper outer flap 21). The front plate breaking guide line L21 is a perforated line with intermittent slits. The spacing and shape of the slits in the front plate breaking guide line L21 are not limited.

[0023] The rear upper outer flap 21 is connected to the upper edge of the rear plate 12 via a rear plate breaking guide line L22. The rear plate breaking guide line L22 is for separating the rear upper outer flap 21 from the rear plate 12, and is formed along the entire upper edge of the rear plate 12 (the rear edge of the rear upper outer flap 21). The rear plate breaking guide line L22 is a perforated line with intermittent slits. The spacing and shape of the slits in the rear plate breaking guide line L22 are not limited.

[0024] As shown in Figures 1 and 2, a pair of front and rear outer break support creases L25, L25 are formed on the front and rear upper outer flaps 21, 21 so as to extend across the entire left-right direction of the upper outer flaps 21, 21. As will be described later, the outer break support creases L25, L25 assist the progression of breakage of the top plate 20 along the front plate break guide line L21 and the rear plate break guide line L22 when the packaging box 1 is opened. Each outer break support crease L25 is formed on the inner surface of each upper outer flap 21. Specifically, each outer break support crease L25 is a linear groove (pressed crease) formed by pressing the inner surface. Therefore, each outer break support crease L25 does not appear on the outer surface of the packaging box 1.

[0025] The outer break support creases L25, L25 are formed symmetrically with respect to a butt line L27 (see FIG. 1 ) formed at the butt portion of the upper outer flaps 21, 21 as a reference line, and have a smooth arc shape. The front outer break support crease L25 is a line that curves in an arc convex toward the upper edge of the front side plate 11, and the rear outer break support crease L25 is a line that curves in an arc convex toward the upper edge of the rear side plate 12. As a result, the front outer break support crease L25 is formed so that the distance between it and the rear outer break support crease L25 increases from the left edge of the front upper outer flap 21 toward the center of the top plate 20 in the left-right direction or from the right edge of the front upper outer flap 21 toward the center of the top plate 20 in the left-right direction. The outer break support creases L25, L25 may be of various shapes such as arc shapes, parabolic shapes, U shapes, etc.

[0026] The left upper inner flap 22 is a rectangular flat plate that extends rightward from the upper edge of the left end plate 13. The left upper inner flap 22 partially covers the left portion of the upper opening of the body 5. The right upper inner flap 22 is a rectangular flat plate that extends leftward from the upper edge of the right end plate 14. The right upper inner flap 22 partially covers the right portion of the upper opening of the body 5.

[0027] The left upper inner flap 22 is connected to the upper edge of the left end plate 13 via a left end plate breakage guide line L23. The left end plate breakage guide line L23 is for separating the left upper inner flap 22 from the left end plate 13 and is formed on the front upper edge and rear upper edge of the left end plate 13. The front and rear left end plate breakage guide lines L23, L23 are connected by a ruled line L23a (see Figure 2) formed on the upper edge of the left end plate 13. The left end plate breakage guide lines L23, L23 are perforated lines with intermittent slits. The spacing and shape of the slits in the left end plate breakage guide lines L23, L23 are not limited.

[0028] The right upper inner flap 22 is connected to the upper edge of the right end plate 14 via a right end plate breakage guide line L24. The right end plate breakage guide line L24 is intended to separate the right upper inner flap 22 from the right end plate 14, and is formed on the front upper edge and rear upper edge of the right end plate 14. The front and rear right end plate breakage guide lines L24, L24 are connected by ruled lines L24a (see Figure 2) formed on the upper edge of the right end plate 14. The right end plate breakage guide lines L24, L24 are perforated lines with intermittent slits. The spacing and shape of the slits in the right end plate breakage guide lines L24, L24 are not limited.

[0029] 1 and 2, a pair of front and rear inner break support creases L26, L26 are formed on the left and right upper inner flaps 22, 22 so as to extend across the entire left-right direction of the upper inner flaps 22, 22. The inner break support creases L26, L26 overlap in the up-down direction with the outer break support creases L25, L25 of the upper outer flaps 21, 21. In other words, the inner break support creases L26, L26 are formed symmetrically with respect to the abutment line L27 (see FIG. 1) between the upper outer flaps 21, 21 as a reference line, and are curved in an arc that overlaps with the outer break support creases L25, L25.

[0030] The inner break support creases L26, L26, together with the outer break support creases L25, L25, help ensure that the progression of the break in the top plate 20 follows the front plate break guide line L21 and the rear plate break guide line L22 of the upper outer flaps 21, 21 when the packaging box 1 is opened. Each inner break support crease L26 is formed on the inner surface of each upper inner flap 22. Specifically, each inner break support crease L26 is a linear groove (pressed crease) formed by pressing into the inner surface.

[0031] The left end plate 13 and the right end plate 14 are provided with tear-off portions 40, 40. The tear-off portion 40 of the left end plate 13 is provided on the top of the left end plate 13 at the center in the front-to-back direction of the left end plate 13. The tear-off portion 40 of the right end plate 14 is provided on the top of the right end plate 14 at the center in the front-to-back direction of the right end plate 14. The tear-off portions 40, 40 function as trigger portions when peeling off the adhesive tape T, and also serve as starting points when opening the top plate 20. The tear-off portions 40, 40 correspond to the attachment positions of both ends T1, T1 of the adhesive tape T. The tearing portion 40 of the left end plate 13 and the tearing portion 40 of the right end plate 14 have the same configuration except that they are arranged in reverse left and right. Therefore, the tearing portion 40 of the left end plate 13 will be described below.

[0032] As shown in Fig. 3, the tearing portion 40 has an upper tearing portion 41 and a lower tearing portion 42 that are separated by a tearing guide line L40. The tearing guide line L40 is a line formed by intermittently forming slits. When the adhesive tape T is pulled and peeled off, the tearing portion 40 is separated from the left end plate 13 together with the adhesive tape T (end T1).

[0033] The upper breaking portion 41 has an inverted trapezoidal shape when viewed from the left. The upper ends of the left and right breaking guide wires L40, L40 that form the upper breaking portion 41 are connected to the ends of the end plate breaking guide wires L23, L23. The lower breaking portion 42 is continuous with the lower side of the upper breaking portion 41 and has a generally oval shape. A finger hook 43 is formed at the lower end of the lower breaking portion 42. In addition, in the tearing portion 40, the end T1 of the adhesive tape T is attached in a state in which the upper tearing portion 41 is almost entirely hidden while a part of the lower tearing portion 42 is exposed, as shown in FIG.

[0034] Next, the action of opening the top plate 20 will be described. When opening, the finger grip 43 of the tearing portion 40 is pushed open, a finger is inserted, and the lower tearing portion 42 is grasped with the fingers and pulled upward. Then, as shown in Figure 4, the upper tearing portion 41 is separated from the left end plate 13 together with the adhesive tape T along the tearing guide line L40, and tearing progresses from the tearing guide lines L40, L40 to the left and right left end plate tearing guide lines L23, L23, which are then cut open to the left and right. This separates the upper inner flap 22 from the upper edge of the left end plate 13.

[0035] Next, when the tearing portion 40 is further pulled up, the fracture progresses from the left end plate fracture guide lines L23, L23 to the front side plate fracture guide line L21 and the rear side plate fracture guide line L22, and then to the right end plate fracture guide line L24 on the right side, causing the top plate 20 to be separated from the upper edge of the body portion 5. As the fracture progresses in this manner, the two upper outer flaps 21, 21 bend at the outer fracture support creases L25, L25, and the two upper inner flaps 22 bend at the inner fracture support creases L26, L26, so that the two upper outer flaps 21, 21 and the two upper inner flaps 22, 22 bend in the same direction. This causes the fracture to progress along the front plate fracture guiding line L21 and the rear plate fracture guiding line L22, preventing it from deviating from the front plate fracture guiding line L21 and the rear plate fracture guiding line L22. Furthermore, because the fracture progresses along the front plate fracture guiding line L21 and the rear plate fracture guiding line L22, the fracture also progresses smoothly from the front plate fracture guiding line L21 and the rear plate fracture guiding line L22 to the right end plate fracture guiding line L24.

[0036] According to the packaging box 1 of this embodiment described above, when the top plate 20 is opened, the outer break support creases L25, L25 and the inner break support creases L26, L26 bend in the same direction, so that the break progresses along the front plate break guide line L21 and the rear plate break guide line L22, and the top plate 20 is smoothly separated from the body 5. This makes it easy to open the top plate 20.

[0037] 5 is an enlarged view of the left end plate 14 (see FIG. 1) and the surrounding area of ​​the opening portion of the left end plate 14 in a blank sheet for a packaging box according to a modified example, viewed from the inside. Although not shown, the right end plate 14 (see FIG. 1) may also be configured in a similar manner. In this modified example, as shown in Figure 5, the left and right left end plate breakage guide lines L23, L23 are connected by an auxiliary breakage guide line L23b. The auxiliary breakage guide line L23b is a perforated line with intermittent slits. The spacing and shape of the slits of the auxiliary breakage guide line L23b are not limited.

[0038] According to this modification, the tearing portion 40 can be separated from the upper inner flap 22 (top plate 20) by the auxiliary breaking guide line L23b. This allows a relatively large opening to be formed at the top of the left end plate 13 for inserting fingers. In this modified example, the opening can be used to firmly grasp the left end of the top plate 20 with the fingers when opening, making the top plate 20 easier to open.

[0039] (Second embodiment) A packaging box according to a second embodiment will be described with reference to Fig. 6. Fig. 6 is an enlarged view of the area around the opening portion of the left end plate of a blank sheet for a packaging box according to the second embodiment of the present invention, viewed from the inside. Although not shown, the right end plate 14 (see Fig. 1) may also be configured in a similar manner. The upper outer flap 21 and the upper inner flap 22 are joined by an adhesive such as hot melt. The same reference numerals are used to designate parts that are the same as those in the first embodiment.

[0040] As shown in Fig. 6, an inverted trapezoidal tearing portion 40A that functions as a product removal opening is formed in the left end plate 13. The tearing portion 40A is defined from the left end plate 13 by a tear initiation portion 43A and front and rear slanted tear guide lines L40A, L40A that extend from the tear initiation portion 43A and serve as tear guide lines for opening. The tear initiation portion 43A is defined by the tear guide line L43A and has a wide fan shape in the front-to-rear direction.

[0041] The front-side oblique break guide line L40A starts from the front portion of the break initiation portion 43A and extends to the front upper corner of the left end plate 13, with its extended end connected to the front plate break guide line L21 of the front plate 11. The rear-side oblique break guide line L40A starts from the rear portion of the break initiation portion 43A and extends to the rear upper corner of the left end plate 13, with its extended end connected to the rear plate break guide line L22 of the rear plate 12. As a result, the inner flap 22 is configured to be connected via the ruled line L41 formed on the upper edge of the left end plate 13. The break guide line L43A and the oblique break guide lines L40A, 40A are perforated lines with intermittent slits. The spacing and shape of the slits in the break guide line L43A and the oblique break guide lines L40A, 40A are not limited.

[0042] A pair of front and rear tear support creases L26a, L26a are formed in the tear portion 40A. The tear support creases L26a, L26a are formed by passing the inner tear support creases L26, L26 of the upper inner flap 22 through the upper edge of the left end plate 13 and extending into the plane of the tear portion 40A. The tear support creases L26a, L26a help ensure that the tearing of the tear portion 40A follows the slanted tear guide lines L40A, 40A. Each slanted tear guide line L40A is a linear groove (pressed crease) formed by pressing the inner surface. Therefore, each slanted tear guide line L40A does not appear on the outer surface of the left end plate 13.

[0043] According to this embodiment, when the tear initiation portion 43A is pinched with the fingers and the tear portion 40A is pulled upward, the tear portion 40A bends at each tear portion tear support crease L26a, allowing the tear portion 40A to be smoothly torn open along each sloping tear guide line L40A. After the tear portion 40A is torn open, tearing progresses from each sloping tear guide line L40A to the front side panel tear guide line L21 and the rear side panel tear guide line L22, and further to the right end panel tear guide line L24, separating the top plate 20 together with the tear portion 40A from the upper edge of the body 5. This facilitates the opening of the top plate 20.

[0044] In this embodiment, the openable portion 40A allows the left end panel 13 to be partially opened for display.

[0045] 7 is an enlarged view of the area around the opening portion of the left end plate, seen from the inside, of a blank sheet for a packaging box according to a modified example of the second embodiment. Although not shown, the right end plate 14 (see FIG. 1) may also be configured in a similar manner.

[0046] 7 is defined by a tear initiation portion 43A, a pair of front and rear linear tear guide lines L40C, L40C, and a pair of front and rear inclined tear guide lines L40B, L40B. The linear tear guide lines L40C, L40C and the pair of front and rear inclined tear guide lines L40B, L40B constitute tear guide lines for opening. The straight break induction wires L40C, L40C are connected to the break initiation portion 43A and extend laterally from the front and rear of the break initiation portion 43A, respectively. The front slanted break induction wire L40B is connected to an end of the front straight break induction wire L40C, passes through the front edge of the left end plate 13, and extends obliquely to the upper edge of the front side plate 11. The extended end of the front slanted break induction wire L40B is connected to the front side plate break induction wire L21 of the front side plate 11. The rear slanted break induction wire L40B is connected to an end of the rear straight break induction wire L40C, passes through the rear edge of the left end plate 13, and extends obliquely to the upper edge of the rear side plate 12. The extended end of the rear slanted break induction wire L40B is connected to the rear side plate break induction wire L22 of the rear side plate 12.

[0047] The tearing portion 40B has a pair of front and rear tearing portion breaking support creases L26a, L26a formed therein, similar to those described above.

[0048] According to a modification of this embodiment, when the tear initiation portion 43A is pinched with the fingers and the tear portion 40B is pulled upward, the tear portion 40B bends at each tear portion tear support crease L26a, allowing the tear portion 40B to be smoothly torn open along each slanted tear guide line L40B. In this case, after the tear initiation portion 43A is torn open, tearing progresses along the linear tear guide lines L40C to the front and rear slanted tear guide lines L40B, L40B. Furthermore, tearing progresses from the slanted tear guide lines L40B to the front side plate tear guide line L21 and the rear side plate tear guide line L22. Then, tearing progresses along the right end plate tear guide line L24, separating the top plate 20 together with the tear portion 40B from the upper edge of the body 5. This facilitates the top plate 20 opening operation.

[0049] Furthermore, in this embodiment, the tear-opening portion 40B reaches the front side panel 11 and the rear side panel 12, so a display mode with a larger opening can be achieved.

[0050] Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments and can be modified as appropriate within the scope of the invention. For example, the outer break support creases L25, L25 are shown formed symmetrically with respect to the butt line L27 as a reference line, but are not limited to this and may not be symmetric. Also, the outer break support creases L25, L25 are shown as being spaced apart from each other as they move toward the center in the left-right direction, but are not limited to this and may be spaced apart at a position offset in the left-right direction from the center in the left-right direction.

[0051] Furthermore, although the inner break support creases L26, L26 are shown overlapping the outer break support creases L25, L25 in the up-down direction, the present invention is not limited to this and may be slightly offset in the front-to-back or left-to-right direction, or may have an arc-shaped curve different from the shape of the outer break support creases L25, L25, or may have a shape that follows (corresponds to) the shape of the outer break support creases L25, L25. In this case as well, the inner break support creases L26, L26 extend in the left-to-right direction and have a shape that follows (corresponds to) the shape of the outer break support creases L25, L25, so that both outer flaps and both inner flaps bend in the same direction, and breaking proceeds smoothly along the front panel break guiding line L21 and the rear panel break guiding line L22.

[0052] Furthermore, although the outer break support creases L25, L25 and the inner break support creases L26, L26 are shown as being curved in an arc, they are not limited to this and various shapes can be used, such as straight lines, broken lines, shapes containing straight lines and curves, dashed lines, etc., as long as the break progresses smoothly along the front panel break guiding lines L21 and the rear panel break guiding lines L22.

[0053] In each of the above-described embodiments, the tear-open portions 40, 40A, 40B are provided on the left end plate 13, etc., but this is not limitative, and the tear-open portions 40, 40A, 40B do not necessarily have to be provided.

[0054] Furthermore, in each of the above embodiments, the top plate 20 is shown to be opened, but this is not limited to this, and the bottom plate 30 may be opened, or both the top plate 20 and the bottom plate 30 may be opened.

[0055] Although the packaging box 1 in each of the above-described embodiments is made of corrugated cardboard, the packaging box may also be made of various known paperboards. [Explanation of symbols]

[0056] 1 packaging box 5. Torso 20 Top plate 30 Bottom plate 11 Front plate (side plate) 12 Rear plate (side plate) 13 Left end plate (end plate) 14 Right end plate (end plate) 21 Upper outer flap (outer flap) 22 Upper inner flap (inner flap) 27 Butt joint 40 Opening part 40A Opening section 40B opening part 43A Break start L21 Front side panel breakage guide wire L22 Rear panel breakage guide wire L23 Left end plate fracture guide wire L24 Right end plate fracture guide wire L25 outer break support crease L26 Inner break support crease L27 Butt line

Claims

1. a trunk portion having a pair of front and rear side plates and a pair of left and right end plates; a bottom plate closing a lower opening of the body; a top plate closing the upper opening of the body, At least one of the bottom plate and the top plate is A packaging box comprising a pair of left and right inner flaps connected to the edge portions of both end plates via at least one of end plate break guide lines and creases, and a pair of front and rear outer flaps connected to the edge portions of both side plates via side plate break guide lines and overlapped on the outer surfaces of the inner flaps, a front outer break support crease provided on the front outer flap, extending in the left-right direction, and curved in an arc shape that is convex toward the edge of the front side plate; a rear outer break support crease provided on the rear outer flap, extending in the left-right direction and curved in an arc shape that is convex toward the edge of the rear side panel; and inner break support creases provided on both inner flaps and curved in an arc along the front outer break support crease and the rear outer break support crease, At least one of the pair of left and right end plates is provided with a tear-starting portion that serves as a starting point when opening, and a tear-guiding wire for opening that is connected to the tear-starting portion, and The packaging box is characterized in that the inner break support crease passes through the edge of the end plate and extends to the opening portion.

2. a trunk portion having a pair of front and rear side plates and a pair of left and right end plates; a bottom plate closing a lower opening of the body; a top plate closing the upper opening of the body, At least one of the bottom plate and the top plate is A packaging box comprising a pair of left and right inner flaps connected to the edge portions of both end plates via at least one of end plate break guide lines and creases, and a pair of front and rear outer flaps connected to the edge portions of both side plates via side plate break guide lines and overlapped on the outer surfaces of the inner flaps, An outer break support crease is provided on the pair of front and rear outer flaps and extends in the left-right direction; an inner break support crease provided on the pair of left and right inner flaps and extending in the left-right direction; The outer break support crease and the inner break support crease overlap each other in the vertical direction, At least one of the pair of left and right end plates is provided with a tear-starting portion that serves as a starting point when opening, and a tear-guiding wire for opening that is connected to the tear-starting portion, and The packaging box is characterized in that the inner break support crease passes through the edge of the end plate and extends to the opening portion.

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