To prevent buckling of waves even in corrugating with press forming after forming waves in a metal plate by inserting an elastic back-up material of the thickness approximately equal to the wave width into a folding part until it abutts to waves and applying pressing with a male and female type die.
When the elastic back-up material 14 of the thickness approximately equal to the wave width into the folding part, in case of corrugating, buckling of waves is prevented while the back-up material 14 is deformed according to the deformation of the metal plate 13. By this way, waves 6 and 7 of the metal plate 13 are kept in a given width after corrugating. And when the back-up material 14 is made of an elastic material, it is taken out and used again after corrugating. Also, the width of the back-up material 14 is preferably specified to be wider than that of engaging bands 4 and 5 in order that the engaging bands 4 and 5 are prevented from bending on the way of its width. A rubber plate is recommended as a preferable back-up material 14.
IIZUKA YUICHI
SAWANO YOSHIO
YAMADA KK
Next Patent: PRESSING METHOD AND DEVICE THEREFOR