The present invention is to improve the appearance of the coffin by eliminating the occurrence of bulges in the outer and inner Tsumaita, providing a prefabricated corrugated coffin that can be widely ensure the receiving space of the can. A cardboard coffin 10 includes a bottom plate 12A made of reinforced cardboard, and the side plate 12B, and Tsumaita 12C. The end of the front and rear of the bottom plate 12A and the side plate 12B, as well as the left and right ends of the Tsumaita 12C, bottom plate frame member 15A made of wood or resin, the side plate frame member 15B, Tsumaita frame member 15C each bottom plate 12A, side plates 12B and Tsumaita 12C and is attached to continuous on substantially the same plane. The end surfaces facing each other of the side plates frame member 15B and Tsumaita frame member 15C engaging groove 16b and the engaging projection 16a is provided in the height direction. When Tsumaita 12C is dropped into the ends of the front and rear of the bottom plate 12A, the engaging protrusion 16b is slid inserted from above into the engaging groove 16a, expansion of the left and right side plates 12B are locked.BACKGROUND 3【課題】妻板の外側および内側に出っ張りが生じるのを解消することで棺の見た目を良好にし、棺内の収納空間を広く確保することが可能な組立式段ボール棺を提供する。【解決手段】段ボール棺10は、強化段ボールからなる底板12Aと、側板12Bと、妻板12Cとを備える。底板12Aおよび側板12Bの前後の端部、並びに妻板12Cの左右の端部には、木材または樹脂からなる底板枠材15A、側板枠材15B、妻板枠材15Cがそれぞれ底板12A、側板12Bおよび妻板12Cとほぼ同一平面上に連なるように取り付けられる。側板枠材15Bと妻板枠材15Cとの互いに向き合う端面には係合溝16bおよび係合突起16aが高さ方向に設けられる。妻板12Cが底板12Aの前後の端部に落とし込まれるとき、係合溝16aに係合突起16bが上方からスライド挿入されることにより、左右の側板12Bの展開がロックされる。【選択図】図3
