Aisin Seiki Kabushiki Kaisha

Kawasaki Steel Corporation

Yoshitomi Onoda

Masami Ishii

Hitoshi Sugimoto

Mitsuhiro Ozawa

Takaaki Toyooka

Akio Ejima

Eiichi Yokoyama

A roll stand used for a cold forming apparatus wherein a body of the roll stand has a slant surface on which a pair of non-driving rolls are installed so as to press sheet metal therebetween. The angle between the slant surface of the body and a base on which the body is installed is adjustable by rotating the body, thereby twisting the sheet metal.

Roll stand for a cold forming apparatus

A roll forming apparatus for forming a flat strip material into a channel shape. This apparatus is composed of a first driving station, a second driving station, and at least two forming stations disposed between the both driving stations. Each driving station respectively contains a pair of driving rolls. The driving rolls of the second driving station is thus constructed to pull the strip at the higher speed than those of the first driving station. Therefore, to the portion of the strip between the first and second driving stations is applied a tensile stress while the strip is sent to the second driving station from the first driving station. At least two forming stations are disposed and respectively contain a pair of forming rolls which are rotated by the moving strip. At the same time, the strip is formed by the forming rolls. As the forming roll used in the present apparatus is a driven roll, maintenance such as adjusting the rotating speed of each station is not necessary. Also insofar as uniform tensile stress is applied to the strip while forming, the resulted strip seldom has an abnormal deformation or twisting. Thus a formed product with high dimensional accuracy can be obtained.

Roll forming apparatus

In a method of forming an electric welded steel tube, wherein a hot-rolled sheet is formed into a cylindrical shape, with the central portion thereof being lowered as the forming progresses, and thereafter, subjected to reduction in the circumferential direction of the tube by means of tandem type fin-pass rolls to be finished into the tube, the proper forming condition ranges capable of eliminating occurrence of edge waves in the tube seam edge portion and/or of cambers in the longitudinal direction of the tube by three forming conditions factors including the downhill value D.sub.H (downhill coefficient .eta.) of the hot-rolled sheet, the fin-pass total reduction R of the tandem type fin-pass rolls and the distribution of the fin-pass reduction (the distribution ratio .delta. of the first fin-pass reduction).

Method of forming electric welded steel tube

Growing community of inventors

Kofu, Japan

Yoshitomi Onoda