Sumitomo Metal Industries, Inc.

Sumitomo Pipe & Tube Co., Ltd.

Nsk Corporation

Nsk Steering Systems Co., Ltd.

H-one Co., Ltd.

Nippon Steel Sumitomo Metal Corporation

Toyoda Iron Works Co., Ltd.

Mitsutoshi Uchida

Atsushi Tomizawa

Saburo Inoue

Fumihiko Kikuchi

Yoshitaka Hattori

Kenji Moroi

Yasushi Watanabe

Mitsutoshi Kano

Masayasu Kojima

Shoichi Abe

Yoshikatsu Iino

Kazumi Shimoii

To form a through hole at one portion of a side wall, of an expanded portion made by plastically deforming one part of a metal tube radially outward, in a portion where the plate thickness gradually changes, a slide tool is withdrawn from inside a punch hole while applying hydraulic pressure to the inside of the side wall. At the instant of commencing withdrawal of the slide tool, the degree of progress in the shearing for the portions of the side wall matching with the two side edges of the punch hole is made different. Then, the timing for moving from shearing to rupture is made to coincide, so that of the side wall, the portions matching with the punch hole, are made reliably into a blank, and are extracted from the side wall.

Manufacturing method for metal member with through hole

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

An impact absorber for a vehicle, which has a tubular shape and which is to be disposed between a side member and a bumper beam of the vehicle, so as to be crushed like an accordion in an axial direction thereof upon application of a compressive load thereto, for absorbing an impact energy. (a) The impact absorber has a tubular main body and a pair of attachment plates that are welded to be fixed to respective axially opposite end portions of the tubular main body. (b) The main body has a thin plate portion having a plate thickness smaller than 1.4 mm and constituting an axially intermediate portion of the main body, and a pair of thick plate portions having a plate thickness not smaller than 1.4 mm and provided integrally on axially opposite sides of the thin plate portion, the thick plate portions being arc-welded to be fixed to the respective attachment plates while being held in contact with the respective attachment plates.

Shock absorbing member for vehicle

According to the hydroforming method by the invention, when slots with the aspect ratio of 3 or more are pierced onto the bulge-formed portion made by the hydroforming, even the piercing can be carried out within a series of processing steps in the hydroforming, thereby eliminating the piercing operation by means of the cumbersome machining process such as milling and ensuring an excellent slot configuration. Thus, the hydroformed parts by the invention are best suited for the automobile parts etc. where various piercing operations are required, and the mold used for the hydroforming method by the invention can be widely employed for processing the automobile parts etc., whereby the invention can be applied for processing the parts in automobiles and industrial machineries as well.

Hydroforming method and mold used for the hydroforming method

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.

Metal tube for reinforcing car body and car body reinforcement therewith

A sheet hydroforming method is disclosed wherein two stacked metallic sheets are clamped between a pair of upper and lower dies and a fluid is introduced and pressurized between mating surfaces of the metallic sheets, causing the metallic sheets to bulge into a space defined by die cavities and A thru-hole for introducing the fluid is formed in one of the dies so as to lead to a holding surface of the die, while a pierced hole for introducing the fluid is formed in one of the metallic sheets in a portion of the one metallic sheet which portion is in contact with a holding surface ( ) of one of the dies, the pierced hole being positioned with the thru-hole then the fluid is introduced in a pressurized state between mating surfaces of the metallic sheets from the thru-hole through the pierced hole, thereby causing the metallic sheets to bulge. According to this method, a pressurized fluid can be introduced between the mating surfaces of blanks easily without leakage of the fluid. Not only the efficiency of the sheet hydroforming method but also the dent resistance of a formed part can be improved.

Metallic sheet hydroforming method, forming die, and formed part

Growing community of inventors

Amagasaki, Japan

Mitsutoshi Uchida