JP6084075B2 - Folding box - Google Patents

Description

  The present invention relates to a folding box used to store, store, or transport various articles.

  Folding boxes are widely used because the volume can be reduced in the absence of containment and the transportation cost and storage cost when not in use can be reduced. It is described in. The folding box described in Patent Document 1 is a folding box made of synthetic resin, and the top sides of a pair of first side walls that regulate the height are hinged to two opposite sides of the top frame. The other two opposite sides are hinged to the upper sides of a pair of second side walls that are foldable by hinges at the middle, and the lower sides of the second side walls are hinged to the two opposite sides of the bottom frame, respectively. It is a connected form.

  In the folding box, the use of a side wall that is foldable by hinge connection at the intermediate part, such as the second side wall, makes the structure of the intermediate hinge part complicated, and the intermediate hinge part is damaged by repeated use. It was easy to occur. Moreover, when using as a cold storage container, it cannot avoid that cold air leaks from the clearance gap formed in the said intermediate hinge part of a 2nd side wall, It was necessary to pay sufficient attention to temperature control.

  In the folding container described in Patent Document 2, the member corresponding to the second side wall is a bent portion that connects the upper partition portion and the lower partition portion, which are aligned in the vertical direction, and the upper partition portion and the lower partition portion. It consists of parts. And the thickness of the said bending part is made thinner than the thickness of the said upper division part and a lower division part. The second side wall of this form can be integrally molded, and durability can be improved by selecting a material. Moreover, since the clearance gap which acts as a ventilation path is not formed in the said bending part, compared with the side wall provided with the hinge connection part in the middle, heat insulation performance is also improved. Furthermore, the upper partition portion and the lower partition portion have a hollow portion, which also improves the heat insulating performance.

JP-A-9-188333 JP 2008-155983 A

  The second side wall in the folding box of the form described in Patent Document 1 is the second side wall of the form described in Patent Document 2, that is, the upper partition part and the lower partition part arranged in parallel in the vertical direction, and the above By replacing with a side wall composed of a bent portion that connects the upper compartment portion and the lower compartment portion, there is a possibility that a folding box having improved durability and improved heat insulation may be obtained.

  Since the thickness of the bent portion is thinner than the thickness of the upper and lower compartment portions, the bent portion is bent when the second side wall is bent, and the upper compartment portion and the lower compartment portion are bent. Folded so that the compartments overlap. At this time, a crease is usually formed at the center in the vertical direction of the bent portion, but a crease may be formed at an unintended portion shifted from the center. Depending on the position where the fold is formed, the durability of the bent portion may be reduced.

  Further, since the thickness of the bent portion is thinner than the thickness of the upper and lower compartment portions, the bent portion is relatively flexible, but the portion where the folds are generated is caused by repeated folding. There was a problem that the strength was likely to be lower than other portions due to whitening.

  This invention is made | formed in view of the above situations, and is provided with the bending part which connects an upper division part, a lower division part, the said upper division part, and a lower division part to a part of side wall. In the folding box using the side wall in a form in which the thickness of the bent portion is thinner than the thickness of the upper and lower compartment portions, the folding is further improved in which the durability of the bent portion is improved. It is an object to provide a box.

  One aspect of the folding box according to the present invention includes a top frame, a bottom frame, a pair of first side walls in which an upper side or a lower side is hinge-connected to any one of the top frame or the bottom frame, and the top side of the top frame. A folding box having a bottom frame hinged with a lower side hinged and a pair of second side walls that can stand upright, wherein the second side wall includes an upper partition part and a lower partition part arranged in parallel in the vertical direction; At least a bent portion connecting the upper partition portion and the lower partition portion, and the upper partition portion and the lower partition portion can be rotated toward the inside of the folding box when the bent portion is bent. The bent portion has a thickness that is thinner than the thickness of the upper partition portion and the lower partition portion, and a curved portion that protrudes toward the inside of the folding box at a part thereof has a full width in the lateral direction. It is formed over the range

  In the folding box of the above aspect, the second side wall includes a bent portion, and the thickness of the bent portion is made thinner than the thickness of the upper partition portion and the lower partition portion connected to the upper and lower sides thereof. The upper partition portion is hinged to the top frame and the lower partition portion is hinged to the bottom frame so that it can be rotated inside the folding box. Therefore, when the folding box is folded, the first side wall is turned so as to be tilted to the inside of the folding box, and the top frame and the bottom frame are brought close to each other, so that the upper partition portion of the second side wall The lower partition portion is rotated so as to fall inside the folding box, and the bent portion between the upper partition portion and the lower partition portion is bent and bent so as to protrude toward the inner side of the folding box. As a result, the second side wall is bent toward the inner side of the folding box, and the upper compartment part and the lower compartment part are folded to fold the folding box.

  At this time, since a curved portion that protrudes in advance toward the inner side of the folding box is formed across the entire width in a part of the folded portion, the folded portion is easily bent at the curved portion. . That is, when a bending stress that bends the bent portion toward the inside of the folding box is applied to the bent portion, the bent portion is easier to bend than the other portions of the bent portion. Therefore, the bent portion is always bent at the curved portion when the second side wall is bent, and an unintended portion of the bent portion is prevented from being bent.

  In addition, since the bending part is easier to bend than other parts of the bent part, the bending part relaxes the stress when the bent part is bent, so that the local stress on the other part is reduced. Concentration is avoided. Further, even when the bent portion is repeatedly bent, the bending portion is less likely to be deteriorated due to bending than the other portions of the bent portion. Therefore, a decrease in strength due to whitening due to repeated bending of the bent portion is prevented, and durability of the bent portion is improved.

  In the folding box of the above aspect, the bent portion may be curved so that the whole is convex toward the inner side of the folding box. In this way, by bending the entire bent portion in advance to the inside of the folding box, it becomes easy to bend the bent portion to be convex toward the inner side of the folding box.

  Moreover, the folding box of said aspect WHEREIN: The said bending part may be provided with the said some bending part in the up-down direction. As a result, a plurality of easily bent portions are formed in the bent portion, and local stress concentration on portions other than the bent portion of the bent portion can be avoided more reliably.

  Further, in the folding box of the above aspect, the second side wall has a thickness of the bent portion that is smaller than a thickness of the upper compartment portion and the lower compartment portion when the second side wall is raised, and is located on the side of the bent portion. A spacer for filling the space to be formed may be provided. Thus, when a load from above acts on the second side wall, the load is received by the spacer. Thereby, it can avoid that a bending part deform | transforms carelessly and can prevent that a 2nd side wall deform | transforms. Further, the area where the bent portion comes into contact with the outside air can be reduced by the presence of the spacer, and the heat insulation performance is also improved. Thereby, a folding box having improved durability and high heat insulation can be obtained.

  ADVANTAGE OF THE INVENTION According to this invention, the more improved folding box which improved the durability of the bending part can be provided.

The perspective view which shows the state in which each side wall in one embodiment of the folding box by this invention stood up. Sectional drawing which follows the II-II line | wire of FIG. Sectional drawing which follows the III-III line of FIG. (A) is a figure which shows the folding middle of the folding box shown in FIG. 1, (b) is a figure which shows after folding. The perspective view which shows the 1st side wall of the folding box shown in FIG. (A) is a front view which shows the state which the 2nd side wall of the folding box shown in FIG. 1 stood up, (b) is a side view. (a) is an enlarged side view of the bent part which shows the state which the 2nd side wall stood up, (b) is an enlarged side view of the bent part which shows the state by which the 2nd side wall was bent. (A) And (b) is an enlarged side view of the 1st modification of a bending part. (A) is an enlarged side view of the 2nd modification of a bending part, (b) is an enlarged side view of the 3rd modification of a bending part. It is a figure which shows the folding box of a comparative example, (a) is an enlarged side view corresponding to Fig.7 (a), (b) is an enlarged side view corresponding to FIG.7 (b).

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  The illustrated folding box A has a rectangular shape in plan view, and includes a top frame 10 and a bottom frame 20, a pair of first side walls 30 and 30, and a pair of second side walls 40 and 40. .

  The top frame 10 includes short side frames 11 and 11 facing each other and long side frames 12 and 12 facing each other, and the top surface is an open surface 13. An appropriate number (two in the illustrated example) of first hinge convex pieces 14 are integrally formed in the vicinity of the upper end on the inner side of each short side frame 11, and the vicinity of the lower end on the inner side of the long side frame 12. An appropriate number (three in the illustrated example) of second hinge convex pieces 15 are also integrally formed at positions. Preferably, the top frame 10 is integrally formed by injection molding using a resin such as polyolefin resin.

  The bottom frame 20 has the same dimensions as the top frame 10, and also has short side frames 21 and 21 facing each other and long side frames 22 and 22 facing each other, and the bottom surface thereof is closed by a bottom plate 23. . In the example shown in the drawing, a convex portion 24 is integrally formed at a substantially central portion inside each short side frame 21. In addition, a bulging portion 25 is formed on the longitudinal side frame 22 over almost the entire length, and a second hinge formed inside the longitudinal side frame 12 of the top frame 10 in the bulging portion 25. A recess 26 for receiving a hinge convex piece 43 formed at the lower end of the lower partition portion 40B of the second side wall 40 to be described later is formed at a location facing the convex piece 15 for use. As shown in the drawing, in this example, the bottom plate 23 is positioned lower than the lower ends of the short side frame 21 and the long side frame 22, and an appropriate cushion material is filled in the stepped portion. Preferably, the bottom frame 20 is integrally molded by an injection molding method using a resin such as a polyolefin resin.

  As shown in FIG. 5, the first side wall 30 includes a side wall body 31 and two sets of hinge convex pieces 32 that are integrally formed on the upper end surface thereof by insert molding. The lateral width W <b> 1 of the side wall main body 31 is substantially equal to the distance between the insides of the long side frames 12, 12 facing the top frame 10 (the distance between the insides of the long side frames 22, 22 of the bottom frame 20 facing each other). The height H <b> 1 is ½ of the distance between the short side frames 11, 11 of the top frame 10 facing each other (the distance between the short side frames 21, 21 of the bottom frame 20 facing each other). In the range which does not exceed, it sets suitably according to the height which the folding box A to obtain obtains. The thickness may be arbitrary.

  The two pairs of hinge convex pieces 32, 32 are formed at positions corresponding to the first hinge convex pieces 14, 14 formed on the inner side of the short side frame 11 of the top frame 10. As shown in the drawing, 32 is fitted (or fitted) between the first hinge convex pieces 14. A recessed portion 33 is formed at the lower end portion of the side wall main body 31 at a position facing the convex portion 24 formed inside the short side frame 21 of the bottom frame 20. The first side wall 30 may be formed of a foamed resin plate of a resin such as a polystyrene resin or a polyolefin resin, and using a resin such as a polyolefin resin, a blow molding method (or an insert) as shown in the figure. The hollow portion 34 may be formed inside by a blow molding method. The hinge convex piece 32 is preferably a non-foamed molded product of a resin such as polyolefin resin.

  The hinge convex pieces 32, 32 formed on the upper end surface of the first side wall 30 are internally fitted to the first hinge convex pieces 14, 14 formed on the inner side of the short side frame 11 of the top frame 10 (or 3), the first side wall 30 is hinged to the short side frame 11 side of the top frame 10 by connecting the two with pins P, and as shown by the phantom line in FIG. The hinge connecting portion can be rotated in the range of 90 degrees inside the folding box A with the hinge as a fulcrum. In the vertical posture, the lower end surface of the bottom frame 20 is brought into contact with the bottom frame 20, and the convex portion 24 formed inside the short side frame 21 of the bottom frame 20 enters the recessed portion 33 formed in the lower end. It becomes. Accordingly, the first side wall 30 regulates the height of the folding box A and stabilizes the standing posture. At the time of folding, as shown in FIG. 4 (b), the first side wall 30 is accommodated in the upper region of the side walls 11, 12 of the top frame 10 by turning upward to the horizontal position inside the folding box A. The Note that the second hinge convex piece 15 formed on the inner side of the longitudinal side wall 12 of the top frame 10 is more than the first side wall 30 in a state where the first side wall 30 is housed in the top frame 10 in a horizontal posture. Is also formed at a lower position.

  Next, the second side wall 40 will be described. As shown in FIG. 6, the second side wall 40 has a rectangular shape in side view as a whole, and includes an upper partition portion 40A and a lower partition portion 40B arranged in parallel in the vertical direction, and these upper partition portion 40A and lower partition portion 40B. And a bent portion 60 connecting the two. The upper partition portion 40A and the lower partition portion 40B have the same dimensions, and both are rectangular in a side view. The upper partition portion 40A and the lower partition portion 40B may be a foamed resin plate made of a resin such as a polystyrene resin or a polyolefin resin. Is formed to have a hollow portion.

  At the time of molding, the bent portion 60 is integrally molded at a position displaced to one side in the thickness direction of the upper partition portion 40A and the lower partition portion 40B. The thickness of the bent portion 60 is made thinner than the thickness of the upper partition portion 40A and the lower partition portion 40B so that the bending is easy. A bent portion 61 that is convex toward the inner side of the folding box A is formed in a part of the bent portion 60 in the lateral direction, that is, over the entire width of the second side wall 40 (see FIG. 1). The bending portion 61 will be described in detail later.

  Three sets of hinge convex pieces 42 are integrally formed on the upper end surface of the upper partition portion 40A by insert molding, and three sets of hinge convex pieces 43 are integrally formed on the lower end surface of the lower partition portion 40B by insert molding. Has been. The hinge convex pieces 42 and 43 are preferably non-foamed molded products of a resin such as polyolefin resin.

  The lateral width W2 of the second side wall 40 is the distance between the short side frames 11, 11 facing the top frame 10 (the distance between the short side frames 21, 21 facing the bottom frame 20). Is almost equal to As shown in FIG. 6, the height H2 of the second side wall 40 is such that the hinge convex piece 42 formed on the upper end surface of the upper partition portion 40A has a top frame when the first side wall 30 is in a standing posture. 10 is located at the position of the second hinge convex piece 15 formed in 10, and the hinge convex piece 43 formed on the lower end surface of the lower partition portion 40 </ b> B enters the recess 26 formed in the bottom frame 20. It is said that it can be taken. Then, the pin P is inserted into the hinge convex piece 42 and the second hinge convex piece 15 to be hinged, and the pin P is inserted between the hinge convex piece 43 and the side wall of the recess 26 to be hinged. By connecting, the second side wall 40 is hinged to the top frame 10 on the upper end side and the bottom frame 20 on the lower end side, depending on the distance between the top frame 10 and the bottom frame 20. The bent portion 60 is in a bent posture with the inside.

  In the second side wall 40, the thickness of the bent portion 60 is thinner than the thickness of the upper partition portion 40 </ b> A and the lower partition portion 40 </ b> B. A space S having a required depth is formed. In order to fill the space S, the second side wall 40 is provided with a spacer 50. The vertical thickness of the spacer 50 is substantially equal to the vertical height of the space S when the second side wall 40 is in the standing posture, and the lateral width of the spacer 50 is substantially equal to the lateral width of the space S. In the example shown in the figure, the spacer 50 is composed of two divided spacers 50A and 50A whose lateral width is half of the lateral width of the space S. A single spacer may cover the entire width of the space S, or two or more divided spacers 50A may cover the entire width of the space S. Preferably, the spacer 50 is a non-foamed molded product of a resin such as a polyolefin-based resin, and is an integrally molded product by injection.

  As shown in FIG. 6A, the split spacer 50 </ b> A includes a rod-shaped main body portion 51 and a locking portion 52 that rises from two locations of the main body portion 51. The height of the main body portion 51 is substantially equal to the height of the space S, and the lateral width is approximately ½ of the lateral width of the space S. The width in the front-rear direction of the main body portion 51 is substantially equal to the depth of the space S, that is, the distance from the front surface of the upper partition portion 40A (lower partition portion 40B) to the apex of the curved portion 61 of the bent portion 60 described above. Further, four concave portions 45 are formed in the front surface portion on the lower end side of the upper partition portion 40A, and the locking portions 52 of the divided spacers 50A enter the concave portions 45, respectively. The thickness of the locking portion of the divided spacer 50A in the front-rear direction is substantially the same as the depth of the recessed portion 45, and the height thereof is substantially equal to the height of the recessed portion 45. The split spacer 50A is fixed to the upper partition portion 40A by the locking portion 52 being locked by an appropriate locking structure 46 of the recessed portion 45.

  Hereinafter, the bent portion 60 and the curved portion 61 will be described in detail. The bent portion 60 connecting the upper partition portion 40A and the lower partition portion 40B of the second side wall 40 is formed with a curved portion 61 shown in FIG. The bending portion 61 is formed by locally bending the center portion in the vertical direction of the bent portion 60 so as to protrude toward the inner side of the folding box A shown in FIG. The curved portion 61 is formed over the entire width W2 of the second side wall 40 shown in FIG. 6A, and the thickness thereof is equal to the thickness of other portions of the bent portion 60. Yes.

  By forming the curved portion 61 in a part of the bent portion 60, a groove-shaped space U having a U-shape in a side view partially surrounded by the curved portion 61 is formed outside the folding box A. . The space U opens toward the outside of the folding box A. The bent part 60 is divided into two parts, an upper part 62 and a lower part 63, by a curved part 61.

  The bent portion 60 is curved so that the whole is convex toward the inner side of the folding box A. The curvature radius of the overall curvature of the bent portion 60 is larger than the curvature radius of the local curvature of the curved portion 61. That is, the bent portion 60 is gently curved as a whole and bulges out so as to protrude toward the inner side of the folding box A. And the curved part 61 is formed in the intermediate part of the up-down direction corresponding to the vertex of the curve, and it curves stepwise so that it may curve locally in the curved part 61, and it may become one step further toward the folding box A inner side. Bulges.

  As shown in FIGS. 7A and 7B, the upper partition portion 40A is freely 180 degrees using the bent portion 60 with respect to the lower partition portion 40B in a state where the spacer 50 is fixed. It is possible to bend up to the angle. Further, when the upper partition portion 40A and the lower partition portion 40B are in a vertically rising posture, the gap between the upper partition portion 40A and the lower partition portion 40B, that is, the thickness of the bent portion 60 is increased by the spacer 50. The space S formed on the side of the bent portion 60 because it is thinner than the thickness of the portion 40A and the lower partition portion 40B is filled with almost no gap between the upper and lower sides.

  Next, the posture at the time of use and folding of the folding box A according to the present invention will be described. 2 and 3 show the state in use. In this state, the pair of first side walls 30, 30 rises vertically with the hinge connecting portion on the short side frame 11, 11 side of the top frame 10 as a fulcrum, and the lower end thereof is the short side of the bottom frame 20. The bottoms of the side frames 21 and 21 are reached. The pair of second side walls 40, 40 are hinge-connected at the upper end side to the hinge connecting portion on the long-side frame 12, 12 side of the top frame 10, and the lower end side is on the long-side frame 22, 22 side of the bottom frame 20. Standing vertically with the hinge connected to the hinge connecting part. The posture of the second side wall 40 in this state is shown in FIG. The user accommodates an appropriate article in the folding box A in this posture, and covers the top frame 10 with a lid (not shown) as necessary for storage or transportation of the article.

  After use, fold to reduce storage space. FIG. 4A shows a state in the middle of folding. First, the pair of first side walls 30 and 30 are rotated around the hinge connecting portion of the top frame 10 as a fulcrum, and are placed in a horizontal posture inside the folding box A. Jump up to. In parallel with the flip-up operation, the middle part of the pair of second side walls 40, 40 is pushed toward the inner side of the folding box A. The state is shown in FIG. As the second side wall 40 bends, the upper partition portion 40A and the lower partition portion 40B rotate so as to fall inside the folding box A, and the top frame 10 and the bottom frame 20 gradually approach the distance. The state shown in FIG. In this state, the upper partition portion 40A and the lower partition portion 40B of the second side wall 40 are folded, and the first side walls 30 and 30 are on the folded upper partition portion 40A. The volume of the folding box A is smaller than that in use.

  Hereinafter, the operation of the folding box A of the present embodiment will be described in comparison with the folding box of the comparative example shown in FIG. In the folding box of the comparative example, as shown in FIG. 10A, the bent portion 600 that connects the upper partition portion 400A and the lower partition portion 400B is formed in a straight line shape, that is, in a planar shape in a side view. In this case, when shifting from the upright state shown in FIG. 10 (a) to the folded state shown in FIG. 10 (b), a fold is formed at an unintended portion 601 that is displaced from the central portion in the vertical direction of the bent portion 600. Sometimes. When a crease is formed in the unintended part 601 in this way, non-uniform and unexpected stress acts on the part 601 and the part 601 is repeatedly bent so that the durability of the bent part 600 is lowered. There is a risk of doing.

  On the other hand, the folding box A of the present embodiment bulges out so that the curved portion 61 protrudes in advance toward the inner side of the folding box A, as shown in FIG. The second side wall 40 is formed across the entire width in the lateral direction, and a space U is formed inside the curved portion 61. As a result, when the upper partition portion 40A and the lower partition portion 40B shift from the upright state shown in FIG. 7A to the folded state shown in FIG. The bent portion 60 is easily bent at the curved portion 61 by elastic deformation more easily. Therefore, when the second side wall 40 is bent, the bent portion 60 is always bent at the curved portion 61, and an unintended portion of the bent portion 60 is prevented from being bent. Therefore, according to the folding box A of this embodiment, the fall of durability of the bending part 60 can be prevented.

  Further, the portion 601 that is repeatedly bent in the folding portion 600 of the folding box of the comparative example is close to 180 degrees when shifting from the upright state shown in FIG. 10 (a) to the folded state shown in FIG. 10 (b). It is bent to an angle. As described above, since the amount of deformation due to bending is large, the bent portion 600 of the comparative example has a problem that the strength of the bent portion 601 is likely to be lower than that of other portions due to whitening of the repeatedly bent portion 601.

  On the other hand, the folding box A of the present embodiment is curved so that the curved portion 61 of the folding portion 60 is convex in advance to the inner side of the folding box A, as shown in FIGS. 7 (a) and (b). Therefore, the amount of deformation caused by bending of the bent portion 60 is reduced. Therefore, even when the bending portion 61 is repeatedly bent, the bending portion 61 is hardly deteriorated. Therefore, according to the folding box A of the present embodiment, even if the bent portion 60 is repeatedly bent by repeated use, the strength is prevented from being lowered due to whitening of the bent portion 60, and durability is improved compared to the conventional case. Can be improved.

  Furthermore, in the folding box of the comparative example, as shown in FIGS. 10A and 10B, it is necessary to apply a relatively large force in order to bend the portion 601 of the bent portion 600 near 180 degrees. Therefore, the bent portion 600 of the comparative example is not only subjected to a large bending stress on the bent portion 601 but also compared to the connection portion 602 with the upper partition portion 400A and the connection portion 603 with the lower partition portion 400B. A large bending stress acts.

  In contrast, the folding box A of the present embodiment acts on the upper portion 62 and the lower portion 63 of the bent portion 60 because the bending portion 61 is easily elastically deformed when the bent portion 60 is bent. The bending stress is relieved by the curved portion 61. Therefore, when shifting from the upright state shown in FIG. 7A to the folded state shown in FIG. 7B, it acts on the connection portion between the upper portion 62 of the bent portion 60 and the upper partition portion 40A and its vicinity. The bending stress is relieved by the curved portion 61. Similarly, bending stress acting on the connection portion between the lower portion 63 of the bent portion 60 and the lower partition portion 40 </ b> B and its vicinity is relieved by the curved portion 61. Further, the bending stress acting on the connection portion between the upper portion 62 and the lower portion 63 with the curved portion 61 is also relaxed. Therefore, the durability of the bent portion 60 is improved.

  Furthermore, in the folding box A of the present embodiment, the entire bent portion 60 is curved so as to be convex toward the inner side of the folding box A. Therefore, it becomes easy to bend the bent portion 60 so as to be convex toward the inner side of the folding box A. Further, when the second side wall 40 is bent, the bent portion 60 is prevented from being bent so as to protrude outward from the folding box A. Further, the bending strength of the upper portion 62 and the lower portion 63 of the bent portion 60 is improved by the bending. Further, since the bent portion 60 is curved in advance toward the inner side of the folding box A, the bending amount when the bent portion 60 is bent is also reduced. Therefore, the durability of the bent portion 60 is improved.

  2 and 3, when the second side wall 40 is in an upright posture, the upper partition portion 40A and the lower partition portion 40B constituting the second side wall 40 are bent portions 60 thereof. Are connected in a state without an air passage. Furthermore, as shown to Fig.7 (a), the space S between the lower end of 40 A of upper division parts formed by the bending part 60, and the upper end of the lower division part 40B was attached to the lower end of 40 A of upper division parts. The spacer 50 fills almost the entire area. Therefore, the heat insulation performance of the 2nd side wall 40 can be improved compared with the side wall with which the conventional intermediate part is hinge-connected. Furthermore, when a large load is applied from above, the load can be received by the spacer 50, so that the second side wall 40 can be prevented from being unnecessarily deformed.

  In the folding box A of the present embodiment, the bent portion 60 has the same thickness at the curved portion 61 and other portions. Therefore, the strength of the curved portion 61 can be maintained and the durability of the bent portion 60 can be improved. In addition, the thickness of the bending portion 61 may be made thinner than other portions of the bent portion 60 to further increase the flexibility of the bending portion 61. Further, the thickness of the bending portion 61 may be made thicker than other portions of the bent portion 60 to further improve the strength of the bending portion 61.

  In the folding box A of the present embodiment, a gap G is formed between the upper partition portion 40A and the lower partition portion 40B in the folding posture shown in FIG. Therefore, as shown in FIGS. 7A and 7B, the bending angle of the bent portion 60 can be made smaller than 180 degrees to improve the durability of the bent portion 60. It should be noted that even if the upper partition part 40A and the lower partition part 40B are brought into close contact with each other in the folding posture shown in FIG. The durability of the bent portion 60 can be improved by the action.

  FIGS. 8A and 8B show a first modification of the bent portion 60 described above. The bent portion 60A of the first modified example is different from the bent portion 60 described above in that three curved portions 61 are provided in the vertical direction. The other points are the same, and the curved portion 61 is formed across the entire width of the bent portion 60A. In the bent portion 60A of the first modified example, the curved portion 61 is provided in the vicinity of the upper end, in the vicinity of the intermediate portion, and in the lower end. Thus, the bent portion 60A is divided into four parts, ie, a first part 62, a second part 63, a third part 64, and a fourth part 65, from the upper partition part 40A toward the lower partition part 40B.

  Thus, by providing the curved portion 61 also in the vicinity of the upper end and the lower end of the bent portion 60A, the bent portion 60A is not only between the second portion 63 and the third portion 64 in the center, but also the first portion. Bending is also facilitated between 62 and the second portion 63 and between the third portion 64 and the fourth portion 65. As a result, the bending stress acting on the first portion 62 at the upper end and the fourth portion 65 at the lower end of the bent portion 60A can be further relaxed. Further, the bending stress acting on the second portion 63 and the third portion 64 can be further relaxed.

  In addition, it is preferable that the number of the curved parts 61 provided in the up-down direction of the bending part 60A is an odd number of 3 or more. Thereby, it is possible to provide the bending portion 61 at the center in the up-down direction of the bent portion 60A, and to arrange the same number of bending portions 61 symmetrically above and below the bending portion 61. When the number of the curved portions 61 of the bent portion 60A is an even number of 2 or more, for example, a plurality may be provided close to the central portion in the vertical direction, or the upper partition portion 40A and the lower partition portion after folding may be provided. Two may be provided at an interval equal to the gap G of 40B.

  FIGS. 9A and 9B show second and third modified examples of the bent portion 60 described above. The bent portion 60B of the second modified example shown in FIG. 9A is not curved as a whole, and is formed in a straight line shape, that is, a planar shape in a side view, so that the bent portion 60 of the above-described embodiment is formed. Is different. Similarly, the bent portion 60C of the third modified example shown in FIG. 9B is not curved as a whole, and is formed in a straight line shape, that is, a planar shape as viewed from the side. It is different from the bent portion 60A. Thus, by forming the bent portions 60B and 60C in a planar shape, the bent portions 60B and 60C can be easily manufactured.

  The embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration is not limited to this embodiment, and even if there is a design change or the like without departing from the gist of the present invention. These are included in the present invention.

A ... folding box, 10 ... top frame, 20 ... bottom frame, 30 ... first side wall, 40 ... second side wall, 40A ... upper partition part, 40B ... lower partition part, 60, 60A, 60B, 60C ... folding Curved portion, 61 ... curved portion, 50 ... spacer, S ... space

Claims (4)

A top frame, a bottom frame, a pair of first side walls hinged to either the top frame or the bottom frame and an upper side or a lower side of the top frame, and a bending in which the upper side is hinged to the bottom frame and the bottom side is hinged And a pair of second side walls that can stand upright, and a folding box comprising:
The second side wall is integrally formed of a polyolefin-based resin, and includes at least an upper partition portion, a lower partition portion, and a bent portion connecting the upper partition portion and the lower partition portion, which are arranged in parallel in the vertical direction. By bending the bent portion, the upper partition portion and the lower partition portion are rotatable toward the inside of the folding box,
The bent portion has a thickness smaller than that of the upper partition portion and the lower partition portion, and when the second side wall is in an upright posture, the thickness direction of the upper partition portion and the lower partition portion is A folding box characterized in that it is formed at a position displaced outward from the folding box, and a curved portion that is convex toward the inner side of the folding box is formed over the entire width in the lateral direction.   The folding box according to claim 1, wherein the bent portion is curved so that the entire bent portion is convex toward the inside of the folding box.   The folding box according to claim 1 or 2, wherein the bent portion includes a plurality of the curved portions in a vertical direction.   The second side wall is a spacer for filling a space formed on the side of the bent portion by the thickness of the bent portion being thinner than the upper and lower compartment portions when standing upright. The folding box according to any one of claims 1 to 3, further comprising:

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