Hitachi, Ltd.

Masakuni Ezumi

Akihiro Satou

Kinya Aota

Yasuo Ishimaru

Kazushige Fukuyori

Hisanori Okamura

Kazusige Fukuyori

Isao Funyuu

Takeshi Kawasaki

Tetsuya Matsunaga

Toshiaki Sagawa

Yoshihiko Ina

Masahiko Sakamoto

Akihiro Sato

Masaki Yono

Isao Funyu

Masaaki Shigeyama

Tsuyoshi Mizusaki

Kouichi Watanabe

Koji Hamada

Ryooji Ishida

Tsuyoshi Fujii

Ryoji Ishida

Masami Ogata

Akihiro Satuo

The purpose of the present invention is to provide a method that can be easily applied to friction stir welding where the thickness of face plates at one welding portion is different from the thickness of face plates at another welding portion. Three shape membershaving two butt joint portions are mounted on a jigThe face plateof shape memberis thick and the face plateof shape memberis thin. The protruded height of projectionis greater at portion B where surface platesbeing welded are thin than the protruded height of projection A where surface platesare thick. The depths for inserting rotary tools to shape membersfor friction stir welding are the same. Friction stir welding is facilitated since the size and insertion depth of all the rotary tools being applied can be the same.

Friction stir welding method and group of shape members for friction stir welding

Face platesandof a hollow shape memberare abutted against face platesandof a hollow shape member. Groovesformed to said face platesandat the abutted region receive projectionsformed to said face platesand. A connecting plateorthogonal to said face platesandis provided to the hollow shape member. There is no connecting plate orthogonal to face platesanddisposed on the end of the hollow shape member. Friction stir welding heat causes the face plate() to move toward the thickness direction of hollow shape membersand, but such movement is suppressed by the grooveand projection. Thereby, the abutted region is welded flatly. Since the hollow shape memberrequires no connecting plate corresponding to plate, the welded members are light in weight.

Friction stir welding method, and hollow shape member for friction stir welding

The purpose of the present invention is to provide a method that can be easily applied to friction stir welding where the thickness of face plates at one welding portion is different from the thickness of face plates at another welding portion. Three shape membershaving two butt joint portions are mounted on a jig. The face plateof shape memberis thick and the face plateof shape memberis thin. The protruded height of projectionis greater at portion B where surface platesbeing welded are thin than the protruded height of projection A where surface platesare thick. The depths for inserting rotary tools to shape membersfor friction stir welding are the same. Friction stir welding is facilitated since the size and insertion depth of all the rotary tools being applied can be the same.

The end of a hollow memberis abutted against the end of a hollow member. The end of a face plateis supported on a protrusion. A small-diameter portionof a rotary toolis inserted into the abutted area, and the toolis moved along the abutted region while being rotated in a clockwise direction as observed from the large-diameter potion. Thus, the pressure of mobilized metal is greater on the right side of the axial center of the rotary tool. The thickness of the member from the tip of the inserted small-diameter portionto the hollow areasandis thicker at the right side where the pressure is higher, thus preventing metal from flowing out into the hollow region

Friction stir welding method

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

Two membersandare butted against each other, and the butted portion is cut with a cutterto form a slitthereto, and a filler memberis inserted to slitusing rollersand. Then, friction stir welding is performed to weld filler memberand two memberanddisposed on both sides thereof using a rotary tool, and the position of a gap formed between an end of filler memberat the upstream side in the rotating direction of rotary tooland one memberat the upstream side in the rotating direction is detected using an optical sensor. Then, half the width of filler memberis added to the detected position, and the calculated position is set as the position of the rotary tool

A cutting toolcuts along the butted portion between two members. A filling materialis inserted to the gapformed by said cutting, and a rollerpresses protrusionsandto crimp said protrusionsandso as to fix said filling material to position. Next, friction stir welding is performed to the protrusionsand the filling materialusing a rotary tool. In another example, instead of cutting, the filling material can be welded and filled to the gap. In yet another example, cutting can be performed so as to approximate the two members before performing the friction stir welding step.

Friction stir welding method, and method for manufacturing car body

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

Grooves formed to face plates and of a hollow shape member at an abutted region with hollow shape member receive projections formed to face plates and of member . A connecting plate orthogonal to the face plates and is provided to the hollow shape member . There is no connecting plate orthogonal to face plates and disposed on the end of the hollow shape member . Friction stir welding heat causes the face plate ( ) to wove toward the thickness direction of hollow shape members and , but such movement is suppressed by the groove and projection . Thereby, the abutted region is welded flatly.

On a main shaft of a numeric control type machine tool, a rotary tool is installed. The main shaft is not inclined in the machine tool. A first member and a second member to be subjected to friction stir welding are fixed on a table . Relative to an axial center of the rotary tool , a non-linear welding portion of the first member and the second member is inclined by inclining the table . Then, by rotating the table and relatively moving the portion to be welded into contact with the rotary tool , welding of the first member to the second member is carried out according to friction stir welding. The above-stated inclination is the inclination required for the friction stir welding. In this way, welding along a path of ring shape or circular shape (including a circular arc) using friction stir welding can be carried out easily.

A rotary tool ( ) having on the end surface of a large-diameter portion ( ) facing a small-diameter portion ( ) grooves ( ) formed in arc-like shapes, and performing friction stir weld by inserting the end surface of the large-diameter portion ( ) and the small-diameter portion to members and rotating the tool ( ). By the rotation, the metal of the members moves along the grooves ( ) to the center axis direction of the rotary tool ( ). The arc-shaped grooves ( )are formed to curve toward the direction of rotation. Since the metal material of the members is moved toward the center, a good weld is realized even when only one of the members to be welded has a projection, or when a large gap is formed therebetween.

Friction stir welding method and rotary tool

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 rim member forming an entrance and a plate ( ) are friction stir welded by moving a rotary tool along the rim member . The rotary tool is tilted along the direction of movement. Welding is started at right block R, and when the tool reaches corner portion P between the right block R and a center block C, the tool is pulled out of the rim member and plate ( ). Next, the tool is tilted toward the direction of movement along center block C. Thereafter, the tool is lowered and inserted to position, and friction stir welding is restarted. According to the invention, the direction of the rotary tool is not changed while the tool is inserted to the rim member . This prevents generation of excessive friction heat, and thereby realizes a good weld.

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

Plural extrusion members , each having plural ribs formed on one surface of a face plate , are mounted on a frame with the surface not having the ribs facing downward, and with the end regions of the adjacent members being butted to each other. Then, the end regions of said members are welded using friction stir welding from the upper direction with a rotary body , and then a hairline finish is applied to said surface not having the ribs, which constitutes the exterior surface of the vehicle body. In this way, there is substantially no need to cut off the joint bead, which improves the appearance of the vehicle body and reduces the manufacturing cost.

Growing community of inventors

Kudamatsu, Japan

Masakuni Ezumi