But expanding wrapping bag

The utility model provides a but expanding wrapping bag, is including the bag body and lie in this internal distraction device of bag, distraction device includes two arc framves and two connecting rods of mirror symmetry, two arc frame one end is articulated each other, two the connecting rod one end articulated other end is each other all connected on the arc frame that corresponds. Connecting rod length is 1.4 with the radius length ratio of arc frame. Two all be equipped with long pivot in the middle of the arc frame, long pivoted joint connecting rod for connecting rod and the support of the articulated of arc frame with the bag body. 种可撑开式包装袋，包括袋本体及位于袋本体内的撑开装置，所述撑开装置包括镜像对称的两根弧形架及两根连杆，两根所述弧形架端相互铰接，两根所述连杆端相互铰接另端均连接在对应的弧形架上。所述连杆长度与弧形架的半径长度比值为1.4。两根所述弧形架中间均设有长枢轴，所述长枢轴连接连杆，用于连杆与弧形架的铰接与袋本体的支撑。