PACKAGING BOX

Abstract

The present invention relates to a packaging box, of which a cubic body can be assembled without the use of packaging tape, twine, or separate portable holder clips, wherein the cubic body, after being completely assembled, can be used in holding and easily transporting various kinds of heavy objects such as daily necessities, without the concern of the box being untied from a fastened state by heavy loads.

Claims

1. A packaging box comprising: a quadrangular box main body; and bottom forming parts each formed to extend from a lower end portion of the quadrangular box main body and bent inward to form a bottom, wherein the bottom forming parts include a front side bottom plate and a rear side bottom plate that are formed to extend from a front side of the lower end portion of the quadrangular box main body and a rear side of the lower end portion, respectively, toward a lower portion of the quadrangular box main body to have ends touching each other when bent inward from the quadrangular box main body and that have a one-side slit and an other-side slit formed at one side and the other side, respectively, in a horizontal direction; and a one-side bottom plate and an other-side bottom plate that are formed to extend from one side of the lower end portion of the quadrangular box main body and the other side of the lower end portion, respectively, toward the lower portion of the quadrangular box main body to be bent inward from the quadrangular box main body and that have a front side cutting line and a rear side cutting line formed at a front side and a rear side, respectively, in the horizontal direction and a front side wing part and a rear side wing part respectively formed on a front side portion downward of the front side cutting line and a rear side portion downward of the rear side cutting line, and in a process in which the front side bottom plate and the rear side bottom plate are each bent inward from the quadrangular box main body, and then the one-side bottom plate and the other-side bottom plate are bent inward from the quadrangular box main body, the front side wing part and the rear side wing part are secured inside the quadrangular box main body in a state in which the front side wing part and the rear side wing part pass through the one-side slit and the other-side slit, respectively.

2. The packaging box of claim 1, wherein a left-right width of the one-side slit and a left-right width of the other-side slit of the front side bottom plate and the rear side bottom plate are the same as an up-down width of the front side wing part and an up-down width of the rear side wing part of the one-side bottom plate and the other-side bottom plate.

3. The packaging box of claim 1, wherein: a one-side cutting line and an other-side cutting line, each formed of a first horizontal cutting line and a first vertical cutting line extending a predetermined length upward from the first horizontal cutting line from each of one side and the other side of the first horizontal cutting line, are formed at one side and the other side of the front side bottom plate and one side and the other side of the rear side bottom plate; and as a portion of the front side bottom plate and a portion of the rear side bottom plate in a direction inward from the one-side cutting line and a direction inward from the other-side cutting line are folded inward from the quadrangular box main body, the one-side slit and the other-side slit are formed inside of the one-side cutting line and inside of the other-side cutting line, respectively.

4. The packaging box of claim 1, wherein a perforated line extending in an up-down direction of the front side wing part and an up-down direction of the rear side wing part is formed at each of a rear side of the front side wing part and a front side of the rear side wing part.

5. The packaging box of claim 1, wherein: an upper cutting line in a vertical direction and a lower cutting line in the vertical direction are formed at an upper portion of a front side of the front side wing part and a lower portion of the front side; an upper securing wing and a lower securing wing that are foldable to be orthogonal to the front side wing part are formed at each of a portion of the front side wing part that is forward from the upper cutting line and a portion of the front side wing part that is forward from the lower cutting line; and a through-hole through which the upper securing wing and the lower securing wing, which are in a folded state, pass is formed at a rear side of the rear side wing part.

6. The packaging box of claim 1, wherein: an upper cutting line in a vertical direction and a lower cutting line in the vertical direction are formed at an upper portion of a front side of the rear side wing part and a lower portion of the front side; an upper securing wing and a lower securing wing that are foldable to be orthogonal to the rear side wing part are formed at each of a portion of the rear side wing part that is rearward from the upper cutting line and a portion of the rear side wing part that is rearward from the lower cutting line; and a through-hole through which the upper securing wing and the lower securing wing, which are in a folded state, pass is formed at a front side of the front side wing part.

7. The packaging box of claim 5, wherein a perforated line extending in a left-right direction of the upper securing wing and a left-right direction of the lower securing wing is formed at a lower portion of the upper securing wing and an upper portion of the lower securing wing.

8. The packaging box of claim 5, wherein: a rear side auxiliary cutting line, formed of a first vertical auxiliary cutting line and a first horizontal auxiliary cutting line extending a predetermined length forward from the first vertical auxiliary cutting line from each of an upper portion and a lower portion of the first vertical auxiliary cutting line, is formed at the rear side of the rear side wing part; and as a portion of the rear side wing part that is in a direction inward from the rear side auxiliary cutting line is folded to be orthogonal to the rear side auxiliary cutting line, the through-hole is formed inside of the rear side auxiliary cutting line.

9. The packaging box of claim 6, wherein: a front side auxiliary cutting line, formed of a first vertical auxiliary cutting line and a first horizontal auxiliary cutting line extending a predetermined length rearward from the first vertical auxiliary cutting line from each of an upper portion and a lower portion of the first vertical auxiliary cutting line, is formed at the front side of the front side wing part; and as a portion of the front side wing part that is in a direction inward from the front side auxiliary cutting line is folded to be orthogonal to the front side auxiliary cutting line, the through-hole is formed inside of the front side auxiliary cutting line.

10. The packaging box of claim 1, wherein: a through-hole is formed at a front side of the front side wing part; a rear side auxiliary cutting line, formed of a first vertical auxiliary cutting line and a first horizontal auxiliary cutting line extending a predetermined length rearward from the first vertical auxiliary cutting line from each of an upper portion and a lower portion of the first vertical auxiliary cutting line, is formed at a rear side of the rear side wing part; and a portion of the rear side wing part that is in a direction inward from the rear side auxiliary cutting line is secured after passing through the through-hole of the front side wing part and being caught in and fixed to the through-hole.

11. The packaging box of claim 1, wherein: a through-hole is formed at a rear side of the rear side wing part; a front side auxiliary cutting line, formed of a first vertical auxiliary cutting line and a first horizontal auxiliary cutting line extending a predetermined length forward from the first vertical auxiliary cutting line from each of an upper portion and a lower portion of the first vertical auxiliary cutting line, is formed at a front side of the front side wing part; and a portion of the front side wing part that is in a direction inward from the front side auxiliary cutting line is secured after passing through the through-hole of the rear side wing part and being caught in and fixed to the through-hole.

12. The packaging box of claim 6, wherein a perforated line extending in a left-right direction of the upper securing wing and a left-right direction of the lower securing wing is formed at a lower portion of the upper securing wing and an upper portion of the lower securing wing.

Description

DESCRIPTION OF DRAWINGS

[0009] FIG. 1 is a development view schematically illustrating a packaging box according to one embodiment of the present invention.

[0010] FIGS. 2 to 4 are cutaway perspective views sequentially illustrating a typical process of assembling bottom forming parts and a process of closing an upper portion of a quadrangular box main body using tape.

[0011] FIG. 5 is a perspective view schematically illustrating a state in which the quadrangular box main body is flipped upside down.

[0012] FIG. 6 is a perspective view schematically illustrating a state in which the bottom forming parts of the upside-down quadrangular box main body are unfolded.

[0013] FIG. 7 is a perspective view schematically illustrating a state in which a front side bottom plate and a rear side bottom plate are bent inward from the upside-down quadrangular box main body.

[0014] FIGS. 8 to 10 are perspective views sequentially illustrating a process in which, as a one-side bottom plate and an other-side bottom plate are bent inward from the upside-down quadrangular box main body, a front side wing part of one example and a rear side wing part of one example pass through a one-side slit and an other-side slit.

[0015] FIGS. 11 to 14 are cutaway perspective views sequentially illustrating a process in which the front side wing part of one example and the rear side wing part of one example are secured inside the quadrangular box main body.

[0016] FIG. 15 is a cross-sectional view along A-A of FIG. 14.

[0017] FIG. 16 is a development view schematically illustrating a packaging box according to another embodiment of the present invention.

[0018] FIG. 17 is a perspective view schematically illustrating a state in which a front side bottom plate, a rear side bottom plate, a one-side bottom plate, and an other-side bottom plate, on which a front side wing part of another example and a rear side wing part of another example are formed, are unfolded.

[0019] FIGS. 18 to 20 are cutaway perspective views sequentially illustrating a process in which the front side wing part of another example and the rear side wing part of another example are secured inside a quadrangular box main body.

[0020] FIG. 21 is a cross-sectional view along B-B of FIG. 20.

MODES OF THE INVENTION

[0021] Hereinafter, preferred embodiments of the present invention will be described in more detail based on the accompanying drawings. Of course, the scope of rights of the present invention is not limited to the following embodiments, and the present invention may be modified in various ways by those of ordinary skill in the art within the scope not departing from the technical gist of the present invention.

[0022] FIG. 1 is a development view schematically illustrating a packaging box according to one embodiment of the present invention, and FIGS. 2 to 4 are cutaway perspective views sequentially illustrating a typical process of assembling bottom forming parts and a process of closing an upper portion of a quadrangular box main body using tape.

[0023] As shown in FIGS. 1 and 2, the packaging box according to one embodiment of the present invention mainly includes a quadrangular box main body 10 and a bottom forming part 20.

[0024] First, an upper portion of the quadrangular box main body 10 may be completely open.

[0025] Alternatively, an upper portion forming part 11 for opening or closing the upper portion of the quadrangular box main body 10 may be formed at the upper portion of the quadrangular box main body 10.

[0026] For example, as shown in FIG. 2, the upper portion forming part 11 may mainly include a front side upper plate 111, a rear side upper plate 112, a one-side upper plate 113, and an other-side upper plate 114.

[0027] The front side upper plate 111 and the rear side upper plate 112 may be formed to vertically extend from a front side of an upper end portion of the quadrangular box main body 10 and a rear side of the upper end portion, respectively, toward the upper portion of the quadrangular box main body 10.

[0028] For an upper end portion of the front side upper plate 111 and an upper end portion of the rear side upper plate 112 to touch each other, the front side upper plate 111 and the rear side upper plate 112 may each be horizontally bent upward inside the quadrangular box main body 10.

[0029] The one-side upper plate 113 and the other-side upper plate 114 may be formed to vertically extend from one side of the upper end portion of the quadrangular box main body 10 and the other side of the upper end portion, respectively, toward the upper portion of the quadrangular box main body 10.

[0030] The one-side upper plate 113 and the other-side upper plate 114 may each be horizontally bent upward inside the quadrangular box main body 10.

[0031] In a state in which the front side upper plate 111 and the rear side upper plate 112 are each horizontally bent upward inside the quadrangular box main body 10 after the one-side upper plate 113 and the other-side upper plate 114 are each horizontally bent upward inside the quadrangular box main body 10, as shown in FIG. 4, packaging tape 3 may be attached at a predetermined length from one side toward the other side of the upper portion forming part 11 at a middle portion of the upper portion forming part 11.

[0032] Next, as shown in FIG. 2, the bottom forming part 20 may mainly include a front side bottom plate 21, a rear side bottom plate 22, a one-side bottom plate 23, and an other-side bottom plate 24.

[0033] The front side bottom plate 21 and the rear side bottom plate 22 may be formed to vertically extend a predetermined length from a front side of a lower end portion of the quadrangular box main body 10 and a rear side of the lower end portion, respectively, toward a lower portion of the quadrangular box main body 10.

[0034] For a lower end portion of the front side bottom plate 21 and a lower end portion of the rear side bottom plate 22 to touch each other, the front side bottom plate 21 and the rear side bottom plate 22 may each be horizontally bent inward from the quadrangular box main body 10.

[0035] A one-side slit 211 and an other-side slit 212 horizontally extending a predetermined length to the left and right may be formed from one side toward the other side of the front side bottom plate 21 and from one side toward the other side of the rear side bottom plate 22 at a one-side middle portion and an other-side middle portion of the front side bottom plate 21 and a one-side middle portion and an other-side middle portion of the rear side bottom plate 22.

[0036] The one-side bottom plate 23 and the other-side bottom plate 24 may be formed to vertically extend a predetermined length from one side of the lower end portion of the quadrangular box main body 10 and the other side of the lower end portion, respectively, toward the lower portion of the quadrangular box main body 10 and may each be horizontally bent inward from the quadrangular box main body 10.

[0037] A front side cutting line 231 and a rear side cutting line 232 that horizontally extend to a predetermined height in a front-rear direction of the one-side bottom plate 23 and in a front-rear direction of the other-side bottom plate 24 may be formed at a front side and a rear side of the one-side bottom plate 23 and a front side and a rear side of the other-side bottom plate 24.

[0038] In addition, a front side wing part 234 may be formed at a front side portion of the one-side bottom plate 23 and a front side portion of the other-side bottom plate 24 downward from the front side cutting line 231.

[0039] A rear side wing part 235 may be formed at a rear side portion of the one-side bottom plate 23 and a rear side portion of the other-side bottom plate 24 downward from the rear side cutting line 232.

[0040] For example, first, as shown in FIG. 3, the one-side bottom plate 23 and the other-side bottom plate 24 are each horizontally bent inward from the quadrangular box main body 10, and then, as shown in FIG. 4, the front side bottom plate 21 and the rear side bottom plate 22 may each be horizontally bent inward from the quadrangular box main body 10.

[0041] FIG. 5 is a perspective view schematically illustrating a state in which the quadrangular box main body is flipped upside down, and FIG. 6 is a perspective view schematically illustrating a state in which the bottom forming parts of the upside-down quadrangular box main body are unfolded.

[0042] Meanwhile, in particular, in order to enable the quadrangular box main body 10 to be assembled in a state in which the lower portion of the quadrangular box main body 10 is easily closed without using packaging tape, string, or a separate portable holder clip, first, as shown in FIGS. 5 and 6, the front side bottom plate 21, the rear side bottom plate 22, the one-side bottom plate 23, and the other-side bottom plate 24, each horizontally bent inward from the quadrangular box main body 10, may be unfolded back to a vertical state.

[0043] FIG. 7 is a perspective view schematically illustrating a state in which a front side bottom plate and a rear side bottom plate are bent inward from the upside-down quadrangular box main body.

[0044] In this state, as shown in FIG. 7, the front side bottom plate 21 and the rear side bottom plate 22 may each be horizontally bent inward from the quadrangular box main body 10.

[0045] FIGS. 8 to 10 are perspective views sequentially illustrating a process in which, as a one-side bottom plate and an other-side bottom plate are bent inward from the upside-down quadrangular box main body, a front side wing part of one example and a rear side wing part of one example pass through a one-side slit and an other-side slit.

[0046] In addition, as shown in FIGS. 8 to 10, in a process in which the one-side bottom plate 23 and the other-side bottom plate 24 are horizontally bent inward from the quadrangular box main body 10, the front side wing part 234 and the rear side wing part 235 may vertically pass through the one-side slit 211 and the other-side slit 212, respectively, while bent toward the one-side slit 211 and the other-side slit 212, respectively.

[0047] Here, for the front side wing part 234 and the rear side wing part 235 to more easily and stably vertically pass through the one-side slit 211 and the other-side slit 212, respectively, preferably, a left-right width (W.sub.1 of FIG. 1) of the one-side slit 211 and a left-right width (W.sub.1 of FIG. 1) of the other-side slit 212 may be the same as an up-down width (W.sub.2 of FIG. 1) of the front side wing part 234 and an up-down width (W.sub.2 of FIG. 1) of the rear side wing part 235.

[0048] In addition, in order to efficiently prevent some daily necessities stored inside the quadrangular box main body 10 from passing through the one-side slit 211 and the other-side slit 212 and falling outward through the lower portion of the quadrangular box main body 10, as shown in FIG. 2, a one-side cutting line 213 and an other-side cutting line 214, each having a rectangular shape with an open top, may be formed at a one-side middle portion and an other-side middle portion of the front side bottom plate 21 and a one-side middle portion and an other-side middle portion of the rear side bottom plate 22.

[0049] For example, the one-side cutting line 213 and the other-side cutting line 214 may each be mainly formed of a first horizontal cutting line 201 and a first vertical cutting line 202.

[0050] The first horizontal cutting line 201 may be formed at a predetermined height while horizontally extending to the left and right from one side toward the other side of the front side bottom plate 21 and from one side toward the other side of the rear side bottom plate 22 at a one-side middle portion and an other-side middle portion of the front side bottom plate 21 and a one-side middle portion and an other-side middle portion of the rear side bottom plate 22.

[0051] The first vertical cutting line 202 may be formed to vertically extend a predetermined length upward from the first horizontal cutting line 201 at each of one side and the other side of the first horizontal cutting line 201.

[0052] A portion of the front side bottom plate 21 and a portion of the rear side bottom plate 22 in a direction inward from the one-side cutting line 213 and a direction inward from the other-side cutting line 214 may close the one-side slit 211 and the other-side slit 212 at ordinary times.

[0053] In addition, as the portion of the front side bottom plate 21 and the portion of the rear side bottom plate 22 in the direction inward from the one-side cutting line 213 and the direction inward from the other-side cutting line 214 are folded inward from the quadrangular box main body 10, the one-side slit 211 and the other-side slit 212, through which the front side wing part 234 and the rear side wing part 235 are able to vertically pass, may be formed.

[0054] Next, for the front side wing part 234 and the rear side wing part 235 to be easily bent toward the one-side slit 211 and the other-side slit 212, respectively, as shown in FIGS. 8 to 10, preferably, a perforated line 29 extending in an up-down direction of the front side wing part 234 and an up-down direction of the rear side wing part 235 may be formed at each of a rear side of the front side wing part 234 and a front side of the rear side wing part 235 as shown in FIGS. 2 and 7.

[0055] Next, for example, as shown in FIG. 2, based on the one-side bottom plate 23, an upper cutting line 203 in the vertical direction and a lower cutting line 204 in the vertical direction may be formed at an upper portion of a front side of the front side wing part 234 and a lower portion of the front side.

[0056] An upper securing wing 25 and a lower securing wing 26 that are foldable to be orthogonal to the front side wing part 234 may be formed at each of a portion of the front side wing part 234 that is forward from the upper cutting line 203 and a portion of the front side wing part 234 that is forward from the lower cutting line 204.

[0057] In addition, a through-hole 236 through which the upper securing wing 25 and the lower securing wing 26, which are in a folded state, pass may be formed at a rear side of the rear side wing part 235.

[0058] In another example, the upper securing wing 25 and the lower securing wing 26 may be formed at portions of the rear side wing part 235, and a through-hole 237 may be formed at a portion of the front side wing part 234.

[0059] For example, as shown in FIG. 2, based on the other-side bottom plate 24, the upper cutting line 203 in the vertical direction and the lower cutting line 204 in the vertical direction may be formed at an upper portion of the front side of the rear side wing part 235 and a lower portion of the front side.

[0060] The upper securing wing 25 and the lower securing wing 26 that are foldable to be orthogonal to the rear side wing part 235 may be formed at each of a portion of the rear side wing part 235 that is rearward from the upper cutting line 203 and a portion of the rear side wing part 235 that is rearward from the lower cutting line 204.

[0061] The through-hole 237 through which the upper securing wing and the lower securing wing, which are in a folded state, pass may be formed at the front side of the front side wing part 234.

[0062] Next, for each of the upper securing wing 25 and the lower securing wing 26 to be more smoothly foldable, as shown in FIG. 2, a perforated line 27 extending a predetermined length to the left and right from one side toward the other side of the upper securing wing 25 and a perforated line 27 extending a predetermined length to the left and right from one side toward the other side of the lower securing wing 26 may be formed at a lower portion of the upper securing wing 25 and an upper portion of the lower securing wing 26, respectively.

[0063] Next, in order to efficiently prevent some daily necessities stored inside the quadrangular box main body 10 from passing through the through-holes 236 and 237 and falling outward through the lower portion of the quadrangular box main body 10, first, as shown in FIG. 2, based on the one-side bottom plate 23, a rear side auxiliary cutting line 30 having a rectangular shape with an open right side may be formed at the rear side of the rear side wing part 235.

[0064] For example, the rear side auxiliary cutting line 30 may be mainly formed of a first vertical auxiliary cutting line 301 and a first horizontal auxiliary cutting line 302.

[0065] The first vertical auxiliary cutting line 301 may be formed to extend a predetermined length in the up-down direction of the rear side wing part 235 from a middle portion of the rear side of the rear side wing part 235.

[0066] The first horizontal auxiliary cutting line 302 may be formed to horizontally extend a predetermined length in a forward direction of the first vertical auxiliary cutting line 301 from each of an upper portion and a lower portion of the first vertical auxiliary cutting line 301

[0067] A portion of the rear side wing part 235 that is inward of the rear side auxiliary cutting line 30 may close the through-hole 236 at ordinary times.

[0068] As the portion of the rear side wing part 235 that is inward of the rear side auxiliary cutting line 30 is folded to be orthogonal to the rear side auxiliary cutting line 30, the through-hole 236 may be formed inside of the rear side auxiliary cutting line 30.

[0069] In addition, as shown in FIG. 2, based on the other-side bottom plate 24, a front side auxiliary cutting line 32 having a rectangular shape with an open left side may be formed at the front side of the front side wing part 234.

[0070] The front side auxiliary cutting line 32 may be formed of a first vertical auxiliary cutting line 321 and a first horizontal auxiliary cutting line 322.

[0071] The first vertical auxiliary cutting line 321 may be formed to extend a predetermined length in the up-down direction of the front side wing part 234 from a middle portion of the front side of the front side wing part 234.

[0072] The first horizontal auxiliary cutting line 322 may be formed to horizontally extend a predetermined length in a rearward direction of the first vertical auxiliary cutting line 321 from each of an upper portion and a lower portion of the first vertical auxiliary cutting line 321.

[0073] A portion of the front side wing part 234 that is inward of the front side auxiliary cutting line 32 may close the through-hole 237 at ordinary times.

[0074] As the portion of the front side wing part 234 that is inward of the front side auxiliary cutting line 32 is folded to be orthogonal to the front side auxiliary cutting line 32, the through-hole 237 may be formed inside of the front side auxiliary cutting line 32.

[0075] FIGS. 11 to 14 are cutaway perspective views sequentially illustrating a process in which the front side wing part of one example and the rear side wing part of one example are secured inside the quadrangular box main body, and FIG. 15 is a cross-sectional view along A-A of FIG. 14.

[0076] As shown in FIGS. 11 to 14, the upper securing wing 25 and the lower securing wing 26 located inside the quadrangular box main body 10 may, while folded to be orthogonal to the front side wing part 234 and the rear side wing part 235, respectively, pass through the through-holes 236 and 237, respectively, and be unfolded back to a horizontal state.

[0077] In this way, as shown in FIGS. 14 and 15, the front side wing part 234 and the rear side wing part 235, which vertically pass through the one-side slit 211 and the other-side slit 212, respectively, may be secured inside the quadrangular box main body 10 and form the bottom forming part 20 of the quadrangular box main body 10.

[0078] Various kinds of heavy-duty objects, such as daily necessities purchased from supermarkets or the like, may be held in the assembled quadrangular box main body 10 and easily transported, and there is no concern about a secure state of the front side wing part 234 and the rear side wing part 235 coming undone due to the heavy-duty objects.

[0079] FIG. 16 is a development view schematically illustrating a packaging box according to another embodiment of the present invention, and FIG. 17 is a perspective view schematically illustrating a state in which a front side bottom plate, a rear side bottom plate, and a one-side bottom plate and an other-side bottom plate, on which a front side wing part of another example and a rear side wing part of another example are formed, are unfolded.

[0080] Next, as shown in FIGS. 16 and 17, a packaging box according to another embodiment of the present invention includes the quadrangular box main body 10 and the bottom forming part 20 like the packaging box according to one embodiment.

[0081] Yet, as shown in FIG. 17, in one example, based on the one-side bottom plate 23, a through-hole 34 may be formed at the middle portion of the front side of the front side wing part 234, and the rear side auxiliary cutting line 30 may be formed at the rear side of the rear side wing part 235.

[0082] The rear side auxiliary cutting line 30 may be formed of the first vertical auxiliary cutting line 301 and the first horizontal auxiliary cutting line 302.

[0083] The first vertical auxiliary cutting line 301 may be formed to extend a predetermined length in the up-down direction of the rear side wing part 235 from a middle portion of the rear side wing part 235.

[0084] The first horizontal auxiliary cutting line 302 may be formed to extend a predetermined length in a rearward direction of the first vertical auxiliary cutting line 301 from each of the upper portion and the lower portion of the first vertical auxiliary cutting line 301.

[0085] In another example, a through-hole 35 may be formed at the middle portion of the rear side of the rear side wing part 235, and the front side auxiliary cutting line 32 may be formed at the front side wing part 234.

[0086] For example, as shown in FIG. 17, based on the other-side bottom plate 24, the front side auxiliary cutting line 32 may be formed of the first vertical auxiliary cutting line 321 and the first horizontal auxiliary cutting line 322 as shown in FIG. 17.

[0087] The first vertical auxiliary cutting line 321 may be formed to extend a predetermined length in the up-down direction of the front side wing part 234 from a middle portion of the front side wing part 234.

[0088] The first horizontal auxiliary cutting line 322 may be formed to extend a predetermined length in a forward direction of the first vertical auxiliary cutting line 321 from each of the upper portion and the lower portion of the first vertical auxiliary cutting line 321.

[0089] FIGS. 18 to 20 are cutaway perspective views sequentially illustrating a process in which the front side wing part of another example and the rear side wing part of another example are secured inside a quadrangular box main body, and FIG. 21 is a cross-sectional view along B-B of FIG. 20.

[0090] As shown in FIGS. 18 to 21, the front side wing part 234 and the rear side wing part 235 may be folded while overlapping each other so that a portion of the rear side wing part 235 that is inward of the rear side auxiliary cutting line 30 is secured after passing through the through-hole 34 of the front side wing part 234 and being caught in and fixed to the through-hole 34 and a portion of the front side wing part 234 that is inward of the front side auxiliary cutting line 32 is secured after passing through the through-hole 35 of the rear side wing part 235 and being caught in and fixed to the through-hole 35.

INDUSTRIAL APPLICABILITY

[0091] According to the present invention, a front side wing part and a rear side wing part formed on a one-side bottom plate and an other-side bottom plate can be secured inside a quadrangular box main body in a state in which the front side wing part and the rear side wing part pass through a one-side slit and an other-side slit of a front side bottom plate and a rear side bottom plate, thereby forming a bottom forming part of the quadrangular box main body, and thus the quadrangular box main body can be assembled in a state in which a lower portion of the quadrangular box main body is easily closed without using packaging tape, string, or a separate portable holder clip, various kinds of heavy-duty objects, such as daily necessities, can be held inside the assembled quadrangular box main body and easily transported, and there is no concern about a secure state of the front side wing part and the rear side wing part coming undone due to the heavy-duty objects.