A temperature sensor is provided inside the protrusion portion of the welding tool, and when welding is performed, the control device controls a rotation speed, a movement speed, or both rotation speed and movement speed of the welding tool, and thus the temperature detected by the temperature sensor is managed so as to fall within the predetermined management temperature range, and welding quality is equalized.

The invention relates to a device and to a method for homogeneously welding two-dimensionally bent structures by friction stir welding.

A method of joining heat-treatable aluminum alloy members by friction stir welding, including the steps of: a T4-treatment-performing step of performing a T4 treatment on heat-treatable aluminum alloy members so as to impart T4 temper to the heat-treatable aluminum alloy members; a joining step of joining the heat-treatable aluminum alloy members with T4 temper by friction stir welding to provide a joined product; and a reversion-treatment-performing step of performing a reversion treatment, the reversion-treatment-performing step being carried out prior to or after the joining step.

A method of fabricating a metal pipeline by friction stir welding (FSW) along a circumferential interface includes spinning first and second FSW tools about respective axes of rotation in contact with a pipe wall to heat, plasticize, and stir respective zones of plasticized metal at the interface. The zone of plasticized metal produced by the second FSW tool extends deeper into the pipe wall than the zone of plasticized metal produced by the first FSW tool. Relative circumferential movement of the FSW tools along the interface is controlled such that the second FSW tool following the first FSW tool enters the zone of plasticized metal produced by the first FSW tool while the metal in that zone remains plastic.

A friction stir welding method for steel sheets includes inserting a rotating tool into an unwelded portion where two or more steel sheets are overlapped or butted together; moving the rotating tool along portions to be welded while rotating the tool so that a softened portion is formed in the steel sheets by friction heat generated between the rotating tool and the steel sheets, and the steel sheets are welded together by utilizing a plastic flow generated by the softened portion being stirred; and preheating the unwelded portion before welding by the rotating tool by a pair of heating devices disposed over and under the unwelded portion and ahead of the rotating tool in the advancing direction to enable high speed welding without the risk of generation of welding defects and damage to the welding tool.

A method of manufacturing a liquid-cooled jacket, includes a preparation step which includes placing a sealing body on a stepped portion to allow a step side surface and a sealing-body side surface of the sealing body to butt each other, and a primary joining step which includes allowing a primary joining rotary tool to move once around the sealing body, while moving the rotary tool along a butted portion formed in the preparation step, to carry out friction stir welding. The primary joining step includes employing the primary joining rotary tool provided with a stirring pin having a length dimension greater than a thickness dimension of the sealing body, and carrying out friction stirring with only the stirring pin being brought into contact with a jacket body and the sealing body.

A method of manufacturing a liquid-cooled jacket, includes a preparation step which includes placing a sealing body on a stepped portion to allow a step side surface and a sealing-body side surface of the sealing body to butt each other, and a primary joining step which includes allowing a primary joining rotary tool to move once around the sealing body, while moving the rotary tool along a butted portion formed in the preparation step, to carry out friction stir welding. The primary joining step includes employing the primary joining rotary tool provided with a stirring pin having a length dimension greater than a thickness dimension of the sealing body, and carrying out friction stirring with only the stirring pin being brought into contact with a jacket body and the sealing body.

A friction stir welding device includes a friction stir welding tool equipped with a fixed shoulder on an outer periphery of a probe on a proximal end side, a main shaft positioning mechanism which relatively moves the friction stir welding tool with respect to a corner portion between workpieces a control device thereof, and a filler supply unit which supplies a filler to a stirring region in which the workpieces are stirred by the probe at the time of friction stir welding. When the probe is immersed into the corner portion to perform the friction stir welding, the fixed shoulder is maintained at a position separated by a gap from the surfaces of the workpieces with the control device.

A friction stir welding apparatus that includes a rotary tool and a heating device. The heating device is placed in front of the rotary tool to heat steel sheets that are used as a workpiece. The rotary tool is moved in the welding direction so that steel sheet is softened by frictional heat. Additionally, the surface temperature, the area, and the position of the heated region during the heating process are strictly controlled. The heating of the steel sheets by the welding apparatus provides sufficient strength and good welding workability by advantageously eliminating plastic flow defects generated due to insufficient heating of workpieces.

An objective of the present invention is to provide a friction stir welding device with which the temperature in the proximity of a weld part on a member to be welded can be intermittently measured by enabling the temperature of a plurality of sites in a rotary tool (4) used for friction stir welding to be ascertained in real-time when welding. This rotary tool (4) for a friction stir welding device comprises: a hollow channel (26a) that extends from the upper end of a shoulder part (4c) to the proximity of the lower end of a probe (4d), and that is on substantially the same axis as the axis of rotation of the shoulder part (4c); and a hollow, outer periphery channel (26b) that is apart from the axis of rotation of the shoulder part (4c) in the radial direction and in proximity of the outer periphery of the shoulder part (4c), and that extends from the upper end of the shoulder part to the proximity of the lower end thereof. A temperature measurement element (5a) is respectively disposed in the proximity of the lower end of the hollow channel and of the outer periphery channel.