Hitachi, Ltd.

Isao Funyuu

Kinya Aota

Masakuni Ezumi

Yasuo Ishimaru

Hisanori Okamura

Akihiro Satou

Akihiro Satuo

Disclosed is a friction stir welding technique which avoids occurrence of a dent, in a joining region, extending to a level beneath the joined surfaces. At end portions of the frame members to be joined, at the joining region, thickened parts which project toward the rotary body joining tool are provided. Two adjoining thickened parts, of adjacent members to be joined, can form a trapezoid shape. The rotary body joining tool has a small-diameter tip portion and a larger diameter portion. The rotary body joining tool is inserted in the thickened parts. In a state where the rotary body joining tool has been inserted small-diameter tip end first, to a level where the larger diameter portion of the rotary body joining tool overlaps the thickened part but does not extend below the upper surface of the non-thickened surfaces of the members joined, the rotary body is rotated and moved along the joining region. Even when a gap exists between two thickened parts, a desirable joining can be carried out. After the joining, the remaining parts of the thickened parts can be machined so as to form a smooth surface.

Friction stir welding method, frame members used therein, and product formed thereby

The friction stir welding technique disclosed avoids occurrence of a dent in adjoining region extending to a level beneath the joined surfaces. At end portions of the frame members to be joined, thickened parts, which project toward the rotary body joining tool, are provided. The Two adjoining thickened parts form a trapezoid shape. The rotary body joining tool has a small-diameter tip portion and a larger diameter portion, and is inserted in the thickened parts. When the rotary body joining tool has been inserted small-diameter tip end first to a level where the larger diameter portion of the rotary body joining tool overlaps the thickened part, the rotary body is rotated and moved along the joining region. Even when a gap exists between two thickened parts, a desirable joining can be carried out. After the joining, the remaining parts of the thickened parts can be machined to form a smooth surface.

Extruded frame member for use in friction stir welding

In a railway car, extruded frame members of an aluminum base alloy containing Si of 0.4-0.9 wt % and Mg of 0.4-1.2 wt % are welded according to a friction stir welding method. In a structure, an aluminum base alloy plate containing Si of 0.4-0.9 wt % and Mg of 0.4-1.2 wt % is prepared, to one face of the aluminum base alloy plate a rib is formed, and the aluminum base alloy plate is an extruded frame member. Accordingly, a railway car having a low welding distortion and a structure having a low welding distortion can be obtained.

Structure and railway car

Disclosed is a friction stir welding technique which avoids occurrence of a dent, in adjoining region, extending to a level beneath the joined surfaces. At end portions of the frame members to be joined, at the joining region, thickened parts which project toward the rotary body joining tool are provided. Two adjoining thickened parts, of adjacent members to be joined, can form a trapezoid shape. The rotary body joining tool has a small-diameter tip portion and a larger diameter portion. The rotary body joining tool is inserted in the thickened parts. In a state where the rotary body joining tool has been inserted small-diameter tip and first, to a level where the larger diameter portion of the rotary body joining tool overlaps the thickened part but does not extend below the upper surface of the non-thickened surfaces of the members joined, the rotary body is rotated and moved along the joining region. Even when a gap exists between two thickened parts, a desirable joining can be carried out. After the joining, the remaining parts of the thickened parts can be machined so as to form a smooth surface.

Structural body formed by friction stir welding

Frame member used in friction stir welding

Disclosed is a friction stir welding technique which avoids occurrence of a dent, in adjoining region, extending to a level beneath the joined surfaces, structural body formed. At end portions of the frame members to be joined, at the joining region, thickened parts which project toward the rotary body joining tool are provided. The rotary body joining tool has a small-diameter tip portion and a larger diameter portion. The rotary body joining tool is inserted in the thickened parts. In a state where the rotary body joining tool has been inserted small-diameter tip end first, to a level where the larger diameter portion of the rotary body joining tool overlaps the thickened part but does not extend below the upper surface of the non-thickened surfaces of the members joined, the rotary body is rotated and moved along the joining region.

Friction stir welding method using members which overlap and have protrusion at the weld location prior to the welding

Structural body formed by friction stir welding method

Structural body formed by friction stir welding two members, one of which has a protruding portion

Method of forming structural body using friction stir welding, and structural body formed

Friction stir welding method including positioning of rotary tool, and structural body formed thereby

Friction stir welding method including removal of protruding portion, and structural body formed thereby

A friction stir welding technique which avoids occurrence of a dent, in a joining region, extending to a level beneath the joined surfaces. At end portions of the frame members to be joined, at the joining region, thickened parts which project toward the rotary body joining tool are provided. Two adjoining thickened parts, of adjacent members to be joined, can form a trapezoid shape. The rotary body joining tool has a small-diameter tip portion and a larger diameter portion. The rotary body joining tool is inserted in the thickened parts. In a state where the rotary body joining tool has been inserted small-diameter tip end first, to a level where the larger diameter portion of the rotary body joining tool overlaps the thickened part but does not extend below the upper surface of the non-thickened surfaces of the members joined, the rotary body is rotated and moved along the joining region. Even when a gap exists between two thickened parts, a desirable joining can be carried out. After the joining, the remaining parts of the thickened parts can be machined so as to form a smooth surface.

Growing community of inventors

Takahagi, Japan

Isao Funyuu