METHOD AND APPARATUS FOR FORMING RECTANGULAR PLATE

PURPOSE:To obtain rectangular plates having highly accurate rectangular wave height and pitch at high mass productivity by pressing a corrugated plate made by preforming a beltlike metallic plate to a corrugated form by gears by a shaping punch. CONSTITUTION:The beltlike metallic plate 6 is inserted into an engaging part of gears 12, 13 rotating in directions A, B to form a corrugated plate 14. The developed length of one wave of the plate 14 is made equal to that of one wave of the rectangular plate to be formed finally. On the other hand, the corrugated plate 14 is inserted into the latter of upper and lower cases 15, 16 containing a shaping section in which shaping punches 17, 18 are supported by a supporting rod 19 and a spring 22 of a shaping device alternately, and the former is superposed on the latter so that the upper punch 17 engages with the lower punch 18. T-shaped punches 17, 18 are fitted to a T-shaped groove of cases 15, 16 and positioning is performed. Further, adjustment is made to make pitch P1 of the punch 17 equal to the pitch of the plate 14 by the length of the spring 22. By applying downward load to the case 15, the spring 22 is contracted, and a rectangular plate having pitch smaller than the pitch p1 is obtained.