JP3070395U - Product packaging support frame having buffer polyurethane film welding surface - Google Patents

Abstract

(57)【要約】 （修正有） 【課題】 製品を梱包する際、従来支持するのが困難で
あった重量、寸法の大きい製品や損傷しやすい電子、精
密機器等を収容しても、屈折、損傷する事なくポリウレ
タンフイルムの緩衝作用に対応する強度を有する支持枠
体の提供。 【解決手段】 折込み角部８を両端に有する前後外壁部
２と前後壁上面部４と、連結切込み１３、連結部底片１
１、連結部上片１２を有する前後連結壁部６を両端に設
けた前後中壁５を連続させ、各部を内側に折り曲げて対
向前後側壁Ａを構成すると共に、相互の前後連結部６の
連結切込み１３により連結させて左右側壁の内壁を構成
し、両端が前記折込み角部８に接続する左右外壁３と左
右挿込み片１４を両端に設けた左右上面部７を連続させ
ると共に、折込み角部８を内側に屈折させて各部を内側
に折り曲げ、左右壁上面部７を前後壁上面部４上に重ね
合わせて、対向左右側壁Ｂを構成する事を特徴としてい
る。 (57) [Summary] (Modifications required) [Problem] When packing a product, it is bent even if it accommodates a product with large weight and dimensions, easily damaged electronics, precision equipment, etc., which was conventionally difficult to support. Provided is a supporting frame having a strength corresponding to a buffering action of a polyurethane film without being damaged. SOLUTION: The front and rear outer wall portions 2 and the front and rear wall upper surface portions 4 each having a bent corner portion 8 at both ends, a connection cut 13 and a connection portion bottom piece 1 are provided.
1. A front and rear middle wall 5 having a front and rear connection wall portion 6 having a connection portion upper piece 12 at both ends is made continuous, and each portion is bent inward to form opposed front and rear side walls A, and a connection between the front and rear connection portions 6 is formed. The inner walls of the left and right side walls are connected by the cuts 13, the left and right outer walls 3 having both ends connected to the bent corners 8 and the left and right upper surfaces 7 provided with the left and right insertion pieces 14 at both ends are connected, and the bent corners are formed. 8 is bent inward and each part is bent inward, and the left and right wall upper surface portions 7 are overlapped on the front and rear wall upper surface portions 4 to form opposed left and right side walls B.

Description

【考案の詳細な説明】[Detailed description of the invention]

【０００１】 ［産業上の利用分野］ 本考案は、製品を梱包する際、ダンボール箱内に嵌合させて使用するポリウレ タンフイルム張りの製品梱包支持枠体に関し、一枚のダンボール材を簡単に組立 てて断面筒状の枠体に構成し、従来支持するのが困難であった重量、寸法の大き い製品や損傷しやすい電子機器、精密機器等を収容しても、緩衝ポリウレタンフ イルムの緩衝作用に対応して製品を損傷させない強度を有する支持枠体である。[0001] The present invention relates to a polyurethane film-lined product packing support frame which is used by being fitted into a cardboard box when packing a product. It is assembled into a cylindrical frame with a cross-sectional shape, and even if it accommodates products that are difficult to support conventionally, such as weight and size products, easily damaged electronic equipment, precision equipment, etc., the cushioning polyurethane film can be used. It is a supporting frame having a strength corresponding to a buffering action and not damaging a product.

【０００２】 ［従来の技術］ 従来、ダンボール材を折り曲げて構成した製品梱包用の支持枠体は、図８に例 示する通り、中央部にフイルム張り穴１０を設けたフイルム溶着面１の四囲を折 り曲げて、前後対向側壁２１と左右対向側壁２２を形成し、上面は開口させた構 造であり、フイルム張り穴１０を覆ってフイルム溶着面１に緩衝用樹脂フイルム を溶着していた。このように構成された従来の支持枠体は、使用の際には、緩衝 用樹脂フイルム面を向かい合わせた状態で重ね合わせ、図７に例示する通り、緩 衝用樹脂フイルム面の間に梱包製品を収納し、緩衝用樹脂フイルムの強靭性とス パンデックス特性により梱包製品に対する緩衝効果を維持させていた。しかしな がら、梱包製品が大型化し重量が増加すると、緩衝用樹脂フイルムが強靭である 程各側壁への荷重が増大するため、輸送中の荷動きで側壁が屈折、倒壊して製品 を損傷する危険が生じる欠点があった。従って、梱包製品の安全確保上、その用 途は小型、軽量の製品の梱包支持枠体に限られていた。2. Description of the Related Art Conventionally, a support frame for packing a product, which is formed by bending a corrugated cardboard material, surrounds a film welding surface 1 provided with a film hole 10 in the center as shown in FIG. Is bent to form the front and rear opposing side walls 21 and the left and right opposing side walls 22, and the upper surface has an open structure. The buffer resin film is welded to the film welding surface 1 so as to cover the film stretch hole 10. . In use, the conventional support frame constructed as described above is overlaid with the buffer resin film surfaces facing each other, and is packed between the cushioning resin film surfaces as illustrated in FIG. The product was stored, and the buffering effect for the packaged product was maintained by the toughness and spandex characteristics of the buffer resin film. However, when the size and weight of the packaged product increase, the load on each side wall increases as the cushioning resin film becomes tougher, and the risk of damage to the product due to bending and collapse of the side wall due to the load movement during transportation. There is a drawback that occurs. Therefore, in order to ensure the safety of packaged products, their use was limited to small and lightweight product packaging support frames.

【０００３】 ［考案が解決しようとする課題］ 従来のダンボール材で構成する梱包支持枠体は強度に乏しく、梱包製品を損傷 させる危険があるので、小型、軽量な製品への使用に限られ、大型及び重量大な る製品や揺動で損傷しやすい電子機器、精密機器等の梱包支持枠体としての使用 には構造的強度に問題があり不適であった。[Problem to be Solved by the Invention] The conventional packaging support frame made of cardboard material has poor strength and has the danger of damaging the packaged product. Therefore, it is limited to use for small and lightweight products. It was unsuitable for use as a packaging support frame for large and heavy products, electronic equipment, precision equipment, etc., which were easily damaged by swinging.

【０００４】 ［課題を解決するための手段］ 本考案は、従来の問題点を解決するために、支持枠体を断面筒状に構成して鋼 性を高め強度を増大し、従来、対応できなかった各種の製品の梱包支持枠体とし て広く使用する事ができものであり、かつ、一枚のダンボール材を無駄無く仕様 し、組立ても簡単な構造である。[Means for Solving the Problems] In order to solve the conventional problems, the present invention provides a support frame body having a cylindrical cross section to enhance the steel properties and increase the strength. It can be widely used as a packaging support frame for various products that did not exist, and it has a simple structure that uses one piece of cardboard material without waste and assembles it.

【０００５】 即ち、本考案は、ダンボール材で構成し、四角形のフイルム溶着面に設けたフ イルム張り穴の対向前後辺に、前後内壁挿込み片を突出させた前後内壁部９を形 成する。折り目を設けた折込み角部８を両端に有する前後外壁部と、左右上面用 挿込み穴及び前後内壁用挿込み穴を設けた前後壁上面部と、連結切込み、連結部 下片、連結部上片を有する前後連結壁部を両端に設けた前後中壁を連続させ、前 記各部を内側に折り曲げて対向前後側壁Ａを構成すると共に、相互の前後連結部 の連結切込みにより連結させて左右側壁の内壁を構成する。又、両端が前記折込 み角部に接続する左右外壁と左右挿込み片を両端に設けた左右上面部を、連続さ せると共に、折込み角部を内側に屈折させて各部を内側に折り曲げ、前記左右挿 込み片を前記左右上面用挿込み穴に挿込み、左右壁上面部を前後壁上面部上に重 ね合わせて、対向左右側壁Ｂを構成する支持枠体である。That is, in the present invention, the front and rear inner wall portions 9 are formed by corrugated cardboard material, and the front and rear inner wall insertion pieces are protruded from the front and rear sides opposite to the film extending holes provided on the square film welding surface. . Front and rear outer wall portions having a folding corner portion 8 provided with a fold at both ends, front and rear wall upper surface portions provided with left and right upper surface insertion holes and front and rear inner wall insertion holes, a connection cut, a connection portion lower piece, and a connection portion upper portion The front and rear middle walls provided at both ends with front and rear connecting wall portions are connected, and the respective portions are bent inward to form opposed front and rear side walls A, and the left and right side walls are connected to each other by connecting cuts of the front and rear connecting portions. Configure the inner wall of. Also, the left and right outer walls, both ends of which are connected to the bent corner, and the left and right upper surfaces provided with left and right insertion pieces at both ends are made continuous, and the bent corner is bent inward to bend each part inward. A support frame body for forming opposed left and right side walls B by inserting left and right insertion pieces into the left and right upper surface insertion holes and overlapping the left and right wall upper surfaces on the front and rear wall upper surfaces.

【０００６】 ［作用］ 本考案は、、図３に例示する通り、前後内壁部９に突出させた前後内壁挿込み 片１７が、フイルム溶着面１に接続して折り込まれた前後中壁部５の上部の前後 内壁用挿込み穴１５に挿し込まれるので、前後外壁部２と前後内壁部９は一定の 間隔をあけた状態で保持されて筒状になり、対向前後側壁Ａの強度は増大する。 又、図４図及び図５に示す通り、前後中壁部５の両端の前後連結部６が左右側壁 Ｂ側に屈折され、図６に示す通り相互の連結切込み１３が噛み合って連結する事 により、左右側壁Ｂの内壁を構成する。この際、図３及び図６に示す通り、連結 下片１１と連結上片１２が左右外壁部３と左右壁上面部７を支持し、左右外壁３ と内壁となる前後連結壁部６及び、フイルム溶着面１と左右壁上面部７の間隔を 保持して筒状となり、枠体としての対向左右側壁Ｂの強度を増大する。[Operation] As shown in FIG. 3, the present invention is characterized in that the front and rear inner wall insertion pieces 17 protruding from the front and rear inner wall parts 9 are connected to the film welding surface 1 and folded into the front and rear middle wall parts 5. Since the front and rear inner wall portions 9 and the front and rear inner wall portions 9 are inserted into the front and rear inner wall insertion holes 15 at a predetermined interval, the front and rear inner wall portions 9 and the front and rear inner wall portions 9 are cylindrical, and the strength of the opposing front and rear side walls A is increased. I do. Also, as shown in FIGS. 4 and 5, the front and rear connecting portions 6 at both ends of the front and rear middle wall portions 5 are bent toward the left and right side walls B, and as shown in FIG. , The inner walls of the left and right side walls B. At this time, as shown in FIGS. 3 and 6, the connecting lower piece 11 and the connecting upper piece 12 support the left and right outer wall portions 3 and the left and right wall upper surface portions 7, and the front and rear connecting wall portions 6 serving as the left and right outer walls 3 and the inner wall, The space between the film welding surface 1 and the left and right wall upper surface portions 7 is maintained to be cylindrical, and the strength of the opposed left and right side walls B as a frame is increased.

【０００７】 又、左右壁上面部７と左右外壁部３を内側に折り込む際、四隅を構成するため 折り目を設けた折込み角部８が、図６に示す通り、一辺が前後外壁部２、他辺が 左右外壁部３に連続した状態で折り込まれ、左右外壁部３と前後連結部６の間に 入り込むので、四隅の強度が増大し、前後外壁部２と左右外壁部３の連結は強固 となる。更に、左右側壁Ｂの左右壁上面部７の両端に突出する左右挿込み片１４ が、前後壁上面部４の左右上面用挿込み穴１６に挿し込まれるので、対向前後側 壁Ａと対向左右側壁Ｂは完全に連結されて一体化し、支持枠体としての強度は著 しく向上する。When folding the left and right wall upper surface 7 and the left and right outer wall 3 inward, a fold corner 8 provided with folds to form four corners has one side as shown in FIG. Since the side is folded in a state of being continuous with the left and right outer wall portions 3 and enters between the left and right outer wall portions 3 and the front and rear connecting portions 6, the strength of the four corners is increased, and the connection between the front and rear outer wall portions 2 and the left and right outer wall portions 3 is firm. Become. Furthermore, since the left and right insertion pieces 14 projecting from both ends of the left and right wall upper surface portions 7 of the left and right side walls B are inserted into the left and right upper surface insertion holes 16 of the front and rear wall upper surface portions 4, the left and right opposed front and rear side walls A are left and right. The side walls B are completely connected and integrated, and the strength as the support frame is remarkably improved.

【０００８】 ［実施例］ 図１の展開図に示す通り、ダンボール材の中央部を四角形のフイルム溶着面１ とし、このフイルム溶着面１に四角形のフイルム張り穴１０を設け、その対向前 後辺に折り目をつけて、前後内壁挿込み片１７を突出させた前後内壁部９を内側 へ突出させる。フイルム溶着面１の対向前後辺には、折り目を設けた折込み角部 ８を両端に有する前後外壁部２と、折り目に左右上面用挿込み穴１６及び前後内 壁用挿込み穴１５を設けた前後壁上面部４と、連結切込み１３を有し、外方に連 結部下片１１、内方に連結部上片１２を有する前後連結壁部６を両端に設けた前 後中壁部５を、それぞれ折り目を設けて外側方向に連続させる。フイルム溶着面 １の対向左右辺には、両端が前記折込み角部８の一辺に接続する左右外壁部３と 、左右挿込み片１４を両端に設けた左右上面部７を、折り目を設けて外側方向に 連続させる。[0008] [Example] As shown in the development of FIG. 1, the central part of the cardboard material is a square film welding surface 1, and the film welding surface 1 is provided with a square film hole 10 and the front and rear sides thereof are opposed to each other. Then, the front and rear inner wall portions 9 with the front and rear inner wall insertion pieces 17 protruding are made to protrude inward. On the front and rear sides opposite to the film welding surface 1, front and rear outer wall portions 2 each having a folding corner portion 8 provided with a fold at both ends, and insertion holes 16 for left and right upper surfaces and insertion holes 15 for front and rear inner walls are provided at the fold. A front / rear middle wall portion 5 having a front and rear wall upper surface portion 4, a connection notch 13, a front and rear connection wall portion 6 having a connection portion lower piece 11 on the outside and a connection portion upper piece 12 on the inside is provided at both ends. , Each of which is provided with a fold so as to be continuous in the outward direction. The left and right outer wall portions 3 having both ends connected to one side of the folding corner portion 8 and the left and right upper surface portions 7 having left and right insertion pieces 14 provided at both ends are provided on the opposite left and right sides of the film welding surface 1 by folds. Continue in the direction.

【０００９】 折り曲げて組み立てる時は、先ず、対向前後側壁Ａを構成する前後外壁部２、 前後壁上面部４、前後中壁部５の順次、内側に折り曲げ、前記前後挿込み片１７ を前記前後内壁用挿込み穴１５に挿し込んで図３及び図４に示す通り、断面筒状 に形成し、対向前後側壁Ａを構成する。この後、、前後連結部６を直角方向に折 り曲げて相互の連結切込み１３を噛み合わせ連結させて対向左右側壁Ｂの内壁を 構成する。次に対向左右側壁Ｂを構成する左右内壁部３、左右壁上面部７を内側 に折り曲げ、折込み角部８を折り目により内側に屈折させて対向左右側壁Ｂを構 成する前後連結部６と左右外壁部３の間に嵌入させた後、前記左右挿込み片１４ を左右上面用挿込み穴１６に挿し込み、左右壁上面部７を前後壁上面部４上に重 ね合わせて、対向左右側壁Ｂを構成する。When bending and assembling, first, the front and rear outer wall portions 2, the front and rear wall upper surface portions 4, and the front and rear middle wall portions 5, which constitute the opposing front and rear side walls A, are sequentially bent inward, and the front and rear insertion pieces 17 are moved forward and backward. As shown in FIGS. 3 and 4, it is inserted into the insertion hole 15 for the inner wall and formed into a cylindrical cross section to form the opposed front and rear side walls A. Thereafter, the front and rear connecting portions 6 are bent at right angles, and the connecting cuts 13 are engaged with each other so as to form an inner wall of the opposed left and right side walls B. Next, the left and right inner wall portions 3 and the left and right wall upper surface portions 7 constituting the opposed left and right side walls B are bent inward, and the bent corner portions 8 are bent inward by the folds to form the front and rear connecting portions 6 which constitute the opposed left and right side walls B. After being fitted between the outer wall portions 3, the left and right insertion pieces 14 are inserted into the left and right upper surface insertion holes 16, and the right and left wall upper surface portions 7 are overlapped on the front and rear wall upper surface portions 4 to face the opposite left and right side walls. Construct B.

【００１０】 このように予め設けた折り目を順次折り込み組み立てる事により、図２に示し た通りの製品梱包支持枠体が完成する。この支持枠体は従来の支持枠体と同様に 、フイルム張り穴１０を覆ってフイルム溶着面１に緩衝用のポリウレタンフイル ム１８を溶着しておく。使用に際しては図７に例示する通り、緩衝用のポリウレ タンフイルム１８面を向かい合わせ、相互のポリウレタンフイルム１８の間に梱 包製品２０を収納して、外装の梱包用ダンボール箱１９内に嵌入させる。従って 、梱包製品２０は強靭性とスパンデックス性に富むポリウレタンフイルム１８に より支持されるので、外部からの衝撃が緩和される。[0010] By sequentially folding and assembling the folds provided in advance in this way, a product packaging support frame as shown in FIG. 2 is completed. As in the case of the conventional support frame, this support frame has a buffer polyurethane film 18 welded to the film welding surface 1 so as to cover the film tension hole 10. At the time of use, as illustrated in FIG. 7, the surfaces of the cushioning polyurethane film 18 face each other, the packaged product 20 is stored between the polyurethane films 18, and is fitted into the outer packaging cardboard box 19. . Accordingly, since the packaged product 20 is supported by the polyurethane film 18 which is rich in toughness and spandex, the impact from the outside is reduced.

【００１１】 本明細書において、各部分の名称に「前後」又は「左右」を付しているが、添 付図面における名称であるから、９０度方向転換すれば「前後」と「左右」が入 れ替わることは周知の通りである。In this specification, “front and rear” or “left and right” is added to the name of each part, but since it is the name in the attached drawing, if the direction is changed by 90 degrees, “front and rear” and “left and right” are changed. It is well known that this is replaced.

【００１２】 ［考案の効果］ 本考案は、使用後の再生可能なダンボール材一枚を簡単に折り曲げて組立る事 により、強固な構造の梱包支持枠体を構成することができるものである。従って 、生産コストの低減となり、断面筒状に構成される枠体は、四囲の側壁及び各側 壁とポリウレタンフイルム溶着面とが強固に連結されているので、溶着したポリ ウレタンフイルムの強靭性とスパンデックス性との相乗効果により、大型、重量 物の製品や衝撃で損傷を受けやすい電子機器、精密機器等の梱包に用いる梱包支 持枠体としての緩衝機能があり、顕著な実効を有するものである。[Effects of the Invention] In the present invention, it is possible to construct a packing support frame having a strong structure by simply bending and assembling a single reusable cardboard material after use. Therefore, the production cost is reduced, and the side wall and each side wall of the frame having a cylindrical cross section are firmly connected to the polyurethane film welding surface, so that the toughness of the welded polyurethane film is reduced. Due to the synergistic effect with spandex properties, it has a cushioning function as a packing support frame used for packing large and heavy products, electronic equipment and precision equipment that are easily damaged by impact, and has a remarkable effect. is there.

【図面の簡単な説明】[Brief description of the drawings]

【図１】本考案に係る梱包支持枠体の実施例の展開図で
ある。FIG. 1 is a development view of an embodiment of a packing support frame according to the present invention.

【図２】図１に示す実施例を組立た梱包支持枠体の完成
斜視図である。FIG. 2 is a completed perspective view of the packing support frame assembled with the embodiment shown in FIG. 1;

【図３】図２に示す組立後の枠の断面を示す斜視図であ
る。FIG. 3 is a perspective view showing a cross section of the frame after assembly shown in FIG. 2;

【図４】図１に示す枠材において、一方の対向側壁の組
立状態を示す斜視図である。FIG. 4 is a perspective view showing an assembled state of one opposing side wall in the frame member shown in FIG. 1;

【図５】図１に示す枠材において、他方の対向側壁の組
立状態を示す斜視図である。FIG. 5 is a perspective view showing an assembled state of the other opposing side wall in the frame member shown in FIG. 1;

【図６】図５に示す組立の際における、角部の組立状態
を示す部分拡大斜視図である。FIG. 6 is a partially enlarged perspective view showing a state of assembling a corner portion at the time of assembling shown in FIG. 5;

【図７】本考案に係る梱包支持枠体を製品梱包に使用し
た状態の断面を示す一部切開正面図である。FIG. 7 is a partially cutaway front view showing a cross section in a state where the packing support frame according to the present invention is used for packing products.

【図８】従来の梱包支持枠体の一例を示す斜視図であ
る。FIG. 8 is a perspective view showing an example of a conventional packing support frame.

【符号の説明】[Explanation of symbols]

Ａ． 対向前後側壁 Ｂ． 対向左右側壁 １． フイルム溶着面 ２． 前後外壁部 ３． 左右外壁部 ４． 前後壁上面部 ５． 前後中壁部 ６． 前後連結壁部 ７． 左右壁上面部 ８． 折込み角部 ９． 前後内壁部 １０． フイルム張り穴 １１． 連結部下片 １２． 連結部上片 １３． 連結切込み １４． 左右挿込み片 １５． 前後内壁用挿込み穴 １６． 左右上面用挿込み穴 １７． 前後内壁挿込み片 １８． ポリウレタンフイルム １９． 梱包用ダンボール箱 ２０． 梱包製品 ２１． 従来の前後対向側壁 ２２， 従来の左右対向側壁 A. Opposite front and rear side walls B. Opposing left and right side walls 1. 1. Film welding surface Front and rear outer walls 3. Left and right outer walls 4. 4. Front and rear wall tops Front and rear middle walls 6. 6. Front and rear connecting wall 7. Left and right wall tops 8. Corner of insert Front and rear inner walls 10. Film tension hole 11. Lower part of connecting part 12. 12. Upper part of connection part Concatenation cut 14. 14. Left and right insertion pieces Insertion holes for front and rear inner walls 16. Right and left upper surface insertion holes 17. Front and rear inner wall insertion pieces 18. Polyurethane film 19. Packing cardboard box 20. Packaging products 21. Conventional front and rear facing side walls 22, Conventional left and right facing side walls

Claims (1)

【実用新案登録請求の範囲】[Utility model registration claims] 【請求項１】 ダンボール材で構成する梱包用支持枠体
において、四角形のフイルム溶着面１に設けたフイルム
張り穴１０の対向前後辺に、前後内壁挿込み片１７を突
出させた前後内壁部９を形成し、折り目を設けた折込み
角部８を両端に有する前後外壁部２と、折り目に左右上
面用挿込み穴１６及び前後内壁用挿込み穴１５を設けた
前後壁上面部４と、連結切込み１３を有し、外方に連結
部下片１１、内方に連結部上片１２を有する前後連結壁
部６を両端に設けた前後中壁５を、折り目を設けて外側
方向に連続させ、前記各部を内側に折り曲げ、前記前後
内壁挿込み片１７を前記前後内壁用挿込み穴１５に挿込
んで、対向前後側壁Ａを構成すると共に、前後連結部６
を直角方向に折り曲げて相互の連結切込み１３を噛み合
わせ連結させて左右側壁の内壁を構成し、両端が前記折
込み角部８に接続する左右外壁３と、左右挿込み片１４
を両端に設けた左右上面部７を、折り目を設けて外側方
向に連続させると共に、折込み角部８を内側に屈折させ
て各部を内側に折り曲げ、前記左右挿込み片１４を前記
左右上面部用挿込み穴１６に挿し込み、左右壁上面部７
を前後壁上面部４上に重ね合わせて対向左右側壁Ｂを構
成する事を特徴とする緩衝用ポリウレタンフイルム溶着
面を有する製品梱包支持枠体。1. A front and rear inner wall portion 9 in which a front and rear inner wall insertion piece 17 protrudes from opposite front and rear sides of a film extending hole 10 provided in a square film welding surface 1 in a packing support frame made of a cardboard material. And the front and rear outer wall portions 2 having the folding corner portions 8 provided with folds at both ends and the front and rear wall upper surface portions 4 having the left and right upper surface insertion holes 16 and the front and rear inner wall insertion holes 15 at the folds. A front and rear middle wall 5 having a notch 13 and a front and rear connection wall portion 6 having a connection portion lower piece 11 on the outer side and a connection portion upper piece 12 on the inner side at both ends is provided with a fold to be continued in the outer direction, The respective portions are bent inward, and the front and rear inner wall insertion pieces 17 are inserted into the front and rear inner wall insertion holes 15 to form opposed front and rear side walls A, and the front and rear connection portions 6 are formed.
Are bent at right angles to form the inner walls of the left and right side walls by meshing and connecting the mutual connecting cuts 13, and the left and right outer walls 3, both ends of which are connected to the bent corners 8, and the left and right insertion pieces 14.
The left and right upper surfaces 7 provided at both ends are provided with folds so as to be continuous in the outward direction, and the bent corners 8 are bent inward to bend each portion inward, so that the left and right insertion pieces 14 are used for the left and right upper surfaces. It is inserted into the insertion hole 16 and
Are laminated on the front and rear wall upper surface 4 to form opposed left and right side walls B.