Hitachi, Ltd.

Kazusige Fukuyori

Masakuni Ezumi

Akihiro Satou

Takeshi Kawasaki

Tetsuya Matsunaga

Yoshihiko Ina

Abutted portions of face plates and of frame members and are friction stir welded. With the abutting, a projecting portion of an end portion of the face plate of the frame member is inserted into a recessed portion of an end portion of the face plate of the frame member . By this engagement, the outer face on one face side of the face plates and form a smooth surface, so that there is no step at the joined edges. Next, a rotary tool is inserted into the gap between the abutted plates, from the side of the raised portions and of the face plates and , while the other faces and of the face plates and are supported flatly on a bed during the friction stir welding. Accordingly, the welding of the engaged plates can be carried out without any step-wise difference.

Frame member for friction stir welding

A raised portion is provided on an upper face of an end portion of a plate which forms one side of a frame member . An end portion of a plate of another frame member is abutted with the plate of the frame member . The frame members and are aluminum alloy extruded frame members and the directions of extrusion of the two frame members are orthogonal. A welding padding is carried on an upper face of the plate of the frame member . Under this condition, a rotary tool is inserted from above and a friction stir welding is carried out. Accordingly, the padding serves the same function on the plate as the raised portion on the plate , so that a good welding can be carried out.

Structural body formed by friction stir welding

Car body formed by friction stir welding

End portions of face plates and of a frame member are connected by a rib A. To protrusion chips and end portions of face plates and of another frame member are overlapped. The corners between the rib A and the rear faces of the face plates and are in the form of a convex circular arc which protrudes into a hollow portion of the frame member . Both end portions of the circular arc are connected to the rib A and the face plates and by two smooth recessed circular arcs and . Accordingly, since a flow-out of metal does not occur from this portion, the cross-section can be small and a light weight structure an be obtained. A structural body formed of hollow frame members which are joined by friction stir welding provides a light weight structure.

Hollow extruded frame member for friction stir welding and structure body formed therefrom

The rotary tools are disposed to weld along two spaced welding lines. The two rotary tools are inserted into respective welding joints and moved at the same time along the respective welding lines. At a position P of a portion of a window one rotary tool is withdrawn from the welding joint to that the friction stir welding on that welding joint is stopped although the welding tool continues to move. At a position P , the rotary tools are gradually withdrawn from their respective welding joints while they continue to move along the welding line. At a position P , the movement of the rotary tools along the respective welding lines is stopped, the rotary tools are completely withdrawn and the welding is stopped. Next, the rotary tools are inserted into the respective welding joints once again and movement thereof is started again. An insertion amount of the rotary tools at this time is larger than the insertion amount thereof prior to the stopping of the movement of these rotary tools.

Method of manufacture of a structural body

The rotary tools are disposed to weld along two spaced welding lines. The two rotary tools are inserted into respective welding joints and moved at the same time along the respective welding lines. At a position P of a portion of a window one rotary tool is withdrawn from the welding joint so that the friction stir welding on that welding joint is stopped although the welding tool continues to move. At a position P the rotary tools are gradually withdrawn from their respective welding joints while they continue to move along the welding line. At a position P the movement of the rotary tools along the respective welding lines is stopped, the rotary tools are completely withdrawn and the welding is stopped. Next, the rotary tools are inserted into the respective welding joints once again and movement thereof is started again. An insertion amount of the rotary tools at this time is larger than the insertion amount thereof prior to the stopping of the movement of these rotary tools.

End portions of face plates and of a frame member are connected by a rib A. To protrusion chips and end portions of face plates and of another frame member are overlapped. The corners between the rib A and the rear faces of the face plates and are in the form of a convex circular arc which protrudes into a hollow portion of the frame member . Both end portions of the circular arc are connected to the rib A and the face plates and by two smooth recessed circular arcs and . Accordingly, since a flow-out of metal does not occur from this portion, the cross-section can be small and a light weight structure can be obtained. A structural body formed of hollow frame members which are joined by friction stir welding provides a light weight structure.

Hollow extruded frame member for friction stir welding

Abutted portion of face plates and of frame members and are friction stir welded. With the abutting, a projecting portion of an end portion of the face plate of the frame member is inserted into a recessed portion of an end portion of the face plate of the frame member . By this engagement, the outer faces on one face side of the face plates and form a smooth surface, so that at the joined edges there is no step. Next, a rotary tool is inserted into the gas between the abutted plates from the side of the raised portions and side of the face plates and , while the other faces and of the face plates and , are supported flatly on a bed during the friction stir welding. Accordingly, the welding of the engaged plates can be carried out without any step-wise difference.

Friction stir welding method

A welding bead is formed along to a jointing potion using friction stir welding on a first frame member and a second frame member , each of which is a hollow extruded molded base member made of an aluminum alloy A6N01 material. When a defect exists in this welding bead 50, the welding bead including this defect is moved by a grinding processing and then a mending zone is formed. In this mending zone, a mending bead is formed using TIG welding. The welding rod used in this TIG welding is made of the same material as the base member of the frame member, and so the composition of the welding bead is formed homogeneously. In the friction stir welding portion, a hairline processing is performed, so that a surface having a beautiful appearance, in which a boundary between the frame members and traces of the defect are inconspicuous, can be obtained. In a case of manufacture of a structural body, such as a railway car, in which an aluminum alloy material is subjected to a friction stir welding, an improvement of the method of mending the friction stir welding portion can be achieved.

Method of mending a friction stir welding portion

The rotary tools are disposed to weld along two spaced welding lines. The two rotary tools are inserted into respective welding joints and moved at the same time along the respective welding lines. At a position P,of a portion of a window one rotary tool is withdrawn from the welding joint so that the friction stir welding on that welding joint is stopped although the welding tool continues to move. At a position P,, the rotary tools are gradually withdrawn from their respective welding joints while they continue to move along the welding line. At a position P,, the movement of the rotary tools along the respective welding lines is stopped, the rotary tools are completely withdrawn and the welding is stopped. Next, the rotary tools are inserted into the respective welding joints once again and movement thereof is started again. An insertion amount of the rotary tools at this time is larger than the insertion amount thereof prior to the stopping of the movement of these rotary tools.

A raised portion,is provided on an upper face of an end portion of a plate,which forms one side of a frame member,An end portion of a plate,of another frame member,is abutted with the plate,of the frame member,The frame members,and,are aluminum alloy extruded frame members and the direction of extrusion of the two frame members are orthogonal. A welding padding is carried on an upper face of the plate,of the frame member,Under this condition, a rotary tool is inserted from above and a friction stir welding is carried out. Accordingly, the padding serves the same function on the plate,the raised portion,on the plate,so that a good welding can be carried out.

A friction stir welding apparatus,comprises members,and,to be subjected to a friction stir welding which members are fixed on a table,, and a joining welding head,which moves in an arrow mark A direction along the table,. A rotary tool,performs the friction stir welding so that a welding bead,is formed. A sensor,irradiates a light beam,on the area to be welded and detects edge portions,and,of the members, and the welding head,is moved and controlled to follow the center of the welded joint. A burr removing cutting means,of the rotary tool,operates to cut off the burr from the weld, causing chips,to be formed. An air jet J injected from an air nozzle is discharged to the outside from a cover,, whereby entry of the chips,into the area of the sensor,can be prevented. In a friction stir welding apparatus, the entry of chips into the area of the sensor,for detecting a center position where the welding joint is located can be prevented.

Manufacturing method of a structure body and a manufacturing apparatus of a structure body

Rotary tools,A and,B are disposed to weld along two joining lines. For this purpose spaced welding lines the two rotary tools are inserted and into respective welding joints moved at the same time along their respective welding lines. At a position P1 of a portion of a window,, the rotary tool,A is retreated from the welding joint so that the tool,A continues to move friction stir welding on that welding joint is stopped although the welding. At a position P3, the rotary tools,B are gradually withdrawn from their respective welding joints while they continue to move along the welding line. At a position P4, the moves of the rotary tools,A and,B is stopped, the rotary tool,B is made to retreat and the joining is made to stop. Next, the rotary tools,A and,B are inserted and the move are started again. An insertion amount of the rotary tool,B is larger than an insertion amount during the stop of the move of the rotary tool. In a case where plural line joining lines are carried out the friction stir joining and in a case of a portion which is unnecessary to carry out the friction stir joining, the good friction stir joining can be obtained.

Manufacturing method of a structural body

End portions of face plates,and,of a frame member,are connected by a rib,A. To protrusion chips,and,end portions of face plates,and,of another frame member,are overlapped. The corners between the rib,A and the rear face of the face plates,and,are in the form of the corners circular arc,which protrudes into a hollow portion,of the frame member,. Both end portions of the circular arc,are connected to the rib,A and the face plates,and,by two smooth recessed circular arcs,and,. Accordingly, since a flow-out of metal does not occur from this portion, the cross-section can be small and a light weight structure can be obtained. A structural body formed of hollow frame members which are joined by friction stir welding provides a light weight structure.

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Kudamatsu, Japan

Kazusige Fukuyori