BLANKING METHOD FOR STEEL PLATE RAW MATERIAL FOR MANUFACTURING ELBOW AND ELBOW MANUFACTURED FROM STEEL PLATE RAW MATERIAL

摘要

PURPOSE:To improve the yield by alternately disposing a bending outside member and an inside member forming split steel plate raw material, with the opening surface outside and opening surface inside half forming edges thereof adjacent to each other. CONSTITUTION:A bending outside member forming split steel plate raw material 2 of a required elbow presenting the substantially oblong rectangle as the whole and an inside member forming split steel plate raw material 3 of a required elbow presenting the substantially hand drum shape as the whole are alternately disposed on a steel plate 1 of a fixed width, with the opening surface outside half forming edge portion (b) and the opening surface inside half forming edge (d) thereof adjacent to each other and blanking is performed. An elbow is formed by coinciding and depositing a bending outside member 2a and a bending inside member 3a which are respectively obtained by press-molding the bending outside member forming split steel plate raw material 2 and the bending inside member forming split steel plate raw material 3 at joining edges (a), (a) and (c), (c) thereof. Thus, the production of residual material can be remarkably decreased and saving of used material can be accomplished.