Sumitomo Pipe & Tube Co., Ltd.

Nippon Steel Sumitomo Metal Corporation

Sumitomo Metal Industries, Inc.

H-one Co., Ltd.

Nippon Steel & Sumikin Pipe Co., Ltd.

Fumihiko Kikuchi

Atsushi Tomizawa

Shinjiro Kuwayama

Saburo Inoue

Mitsutoshi Uchida

Yoshitaka Hattori

Kenji Moroi

Yoshikatsu Iino

Naoki Shimada

A method for three-dimensionally bending a workpiece comprises feeding the workpiece by a feeding unit provided at an upstream side of the workpiece, supporting the workpiece by a supporting unit at a downstream side of the feeding unit, processing the workpiece by clamping the workpiece with a three-dimensionally movable unit that is provided downstream of the supporting unit, heating a local part of the workpiece in a temperature range which allows quenching to be performed, applying a bending moment to the heated local part of the workpiece by the three-dimensionally movable unit in association with the supporting position and/or the moving speed of the workpiece after the heating step, and rapidly quenching the heated portion. Even when a high-strength workpiece is bent, it is possible to effectively obtain a product having excellent shape fixability and uniform hardness distribution at low costs for wide application for bending sophisticated automobile parts.

Method for three-dimensionally bending workpiece and bent product

A three-dimensionally bending machine comprises a supporting unit to support a workpiece and a feeding unit to feed the workpiece from an upstream side of the workpiece. A heating and cooling unit, provided around the outer circumference of a portion of the workpiece downstream of said supporting unit heats the portion of workpiece in a temperature range for plastic deformation and quenches and rapidly cools the deformed workpiece. A three-dimensionally movable unit, provided downstream of said heating and cooling unit, supports the metal material and controls the supporting position and/or the moving speed of the metal material to apply the bending moment in association with a feed amount, a heating amount, and a cooling amount of the workpiece. Even when a high-strength workpiece is bent, a workpiece having excellent shape fixability and uniform hardness distribution can be made, especially for application to sophisticated automobile parts.

Three-dimensionally bending machine, bending-equipment line, and bent product

Using as a vehicle body reinforcing member a bent tube with mixed bends of inward and outward projection according to the present invention makes it possible, during a vehicle body collision, to absorb more energy than and exhibit better impact resistance than a vehicle body reinforcing member that uses one of a known straight tube and a curved tube of radius R entirely. Thus the dimensions (outside diameter, wall thickness) of the steel tube that is used as the vehicle body reinforcing member can be reduced, and the tube shape can be modified, while impact resistance is maintained. Modifying the shape in this manner makes it possible to provide the ever higher required level of vehicle body impact resistance at the same time that it reduces the weight of the vehicle body and lowers the cost. The present invention can therefore be widely used as an occupant protection technology.

Vehicle body reinforcing member

A product intermittently having a bent portion which curves three-dimensionally and a quenched portion is manufactured by performing bending downstream of a support means while feeding a metal material which is supported by the support means from an upstream side towards a downstream side. A portion of the metal material is heated by a heating means downstream of the support means. A bending moment is imparted to the portion of the metal material heated by the heating means to three-dimensionally change the position of a movable roller die which is disposed downstream of the heating means and has a plurality of rolls which feed the heated metal material in the axial direction, and the metal material is quenched by spraying a cooling medium at the portion of the metal material which was heated by a cooling means disposed between the heating means and the movable roller die.

Method of manufacturing a bent product and an apparatus and a continuous line for manufacturing the same

A metal tube for reinforcing car body, and a car body reinforcement according to the invention have a curved portion extending over the entire longitudinal length or a local longitudinal length, wherein, when the reinforcement is assembled such that the outer periphery of the curved portion is aligned substantially in the direction of impact applied to the car body, the load ramp gradient, the maximum load and the absorbed energy are all enhanced in case of a car body collision. Particularly, an increase in the load ramp gradient as for the load property at the start of deformation provides an excellent crash capacity in reinforcing the car body. Moreover, the metal tube and the reinforcement according to the invention are capable of satisfying the current requirements for much more crash capacity of the car body, along with both a weight reduction of the car body and a reduced manufacturing cost, and therefore they are applicable in a wide field for protecting occupants in an automobile.

Growing community of inventors

Tokyo, Japan

Fumihiko Kikuchi