PROBLEM TO BE SOLVED: To provide a springy core material having such properties as to, when a certain amount of force is applied thereto, while bending, move forward/backward in a specific direction (e.g., in a direction forward a reference line), however, even when the force is applied thereto, be less prone to move in the opposite direction (rearward the reference line).SOLUTION: A planar springy core material (1) molded integrally, includes left/right spiral parts (2 and 4) located apart from each other and a central bend part (3) located at a center of the left/right spiral parts (2 and 4). The winding directions of the left/right spiral parts (2 and 4) are inverse. A relationship between the height (a) of the left/right spiral parts (2 and 4) and the height b of the central bend part (3) is b≥a. The thickness of the left/right spiral parts (2 and 4) and the thickness of the central bend part (3) are the same, and the left/right spiral parts and the central bend part are located planarly and do not intersect with each other three-dimensionally.SELECTED DRAWING: Figure 1COPYRIGHT: (C)2018,JPO&INPIT【課題】 ある程度力を加えると特定の方向(例えば基準線よりも前方)へは屈曲しながら進退するが、その逆方向(同後方)には力を加えても動きにくい性質を有するバネ性芯材を提供する。【解決手段】 一体成形された平面状のバネ性芯材(1)である。離れて位置する左右渦巻部(2,4)と、前記左右渦巻部(2,4)の中央に位置する中央湾曲部(3)を有する。前記左右渦巻部(2,4)の渦の巻方向は逆である。前記左右渦巻部(2,4)の高さaと前記中央湾曲部(3)の高さbがb≧aの関係にある。前記左右渦巻部(2,4)の厚みと前記中央湾曲部(3)の厚みが同じであり、平面状に位置して、立体交差していない。【選択図】図1
