| 摘要 |
<p>PURPOSE:To enable improvement of deformation strength due to the external pressure and reduction of the thickness of a utilized stock by making boundary ridge lines and cross parts relatively projecting to the outside of the can in comparison with structural unit surfaces in a polyhedral wall of a part of a can shell which has the structural unit surfaces, the boundary ridge lines and their cross parts. CONSTITUTION:The main part of the can shell provides the structural unit surfaces 20 of surface symmetry in the horizontal direction and bent in the axial direction, the boundary ridge lines 30 through which the structural unit surfaces come in contact with each other and the cross parts through which the boundary ridge lines cross each other. The boundary ridge lines and the cross parts are relatively projecting to the outside of the can in comparison with the structural unit surfaces. The can-axial arrangement of the structural unit surfaces adjoined makes a phase difference an this polyhedral wall is formed by engaging the cylindrical can shell forcedly with a forming die controlling at least one of the inside or the outside of the structural unit surface or the boundary ridge line. In this way, the deformation strength due to the external pressure is improved unexpectedly and the can wall can be made thin.</p> |
