Kobe Steel, Ltd.

Takeo Sakurai

Yoshihaya Imamura

Masatoshi Yoshida

Haruyuki Konishi

Hiroshi Tanimoto

Noritaka Eguchi

Yasuo Takaki

Kwangjin Lee

Disclosed is an Al&#x2014;Mg&#x2014;Si aluminum alloy sheet that can prevent ridging marks during press forming and has good reproducibility even with stricter fabricating conditions. In an Al&#x2014;Mg&#x2014;Si aluminum alloy sheet of a specific composition, hot rolling is performed on the basis of a set relationship between the rolling start temperature Ts and the rolling finish temperature Tf&#xb0; C., whereby the relationship of the cube orientation distribution profile in the horizontal direction of the sheet with the cube orientation alone or another crystal orientation distribution profile at various locations in the depth direction of the sheet is made more uniform, suppressing the appearance of ridging marks that develop during sheet press forming.

Aluminum alloy sheet with excellent post-fabrication surface qualities and method of manufacturing same

The invention provides a press forming method of an aluminum alloy sheet and a press device capable of forming a large panel which is an automobile body outer panel such as a luggage outer panel and the like and is of a shape difficult in forming. In a method of press forming of the aluminum alloy sheetinto a formed product panel having non-contact outer peripheral partsnot contacting the punch for forming the center part of the panel until the vicinity of the bottom dead point, the first punch forming the center partof the panel and the second punchcapable of shifting independently with respect to the first punch are provided, and these punches are interlocked with each other so that the second punchis made contact the non-contact outer peripheral partsof the sheet with the relative position of the second punchwith respect to the first punchbeing shifted to the diceside.

Press forming method for aluminum alloy sheet and pressing device

A metal mold is disposed adjacent to the outer circumference of a base ring, and has a molding face in the inner circumference and a plurality of grooves for forming beads on the molding face along the circumferential direction. A coil for electromagnetic forming is disposed adjacent to the inner circumference of the base ring. When a momentary large current is applied to the coil in this arrangement, the diameter of the base ring is expanded by pressing the base ring toward the molding face of the metal mold such that the base ring is molded into a shape corresponding to the molding face by electromagnetic forming. Improvements such as a metal mold capable of degassing, a separable metal mold, roll-correcting after electromagnetic forming, application of momentary large current over several times, a metal mold with a cutting blade, use of a base ring with a large number of holes, and a metal mold with positioning means are then added. With these improvements, a highly accurate cylindrical ring with beads can be produced at low cost and with high productivity.

Process for producing tubular ring with beads and die for use therein

Growing community of inventors

Moka, Japan

Takeo Sakurai