Abstract: A friction stir spot welder includes a pin, a shoulder, a rotary driver, an advance-retract driver, and circuitry. When a preset and predetermined first period of time has elapsed in a state where a speed of the rotating shoulder in an axial direction or a speed of the pin in the axial direction is a preset and predetermined first speed, the circuitry determines that the tip of the shoulder or the tip of the pin has reached a contact surface of a second workpiece which is in contact with a first workpiece.

Abstract: A friction stir spot welding apparatus includes a pin member formed in a solid cylindrical shape, a shoulder member formed in a hollow cylindrical shape, the pin member being inserted in the shoulder member, a rotary actuator that rotates the pin member and the shoulder member on an axis that is in agreement with an axial center of the pin member, and a linear actuator that linearly moves each of the pin member and the shoulder member along the axis. A tip-end part of the shoulder member is formed in a tapered shape.

Abstract: A joining system (100) of the present invention is for joining a joining target (W) including first, second, and third members (W1), (W2), (W3), and includes a welder (101), a friction stir welding machine (102), and a controller (110) that: (A) causes the welder (101) to weld the second and third members (W2), (W3); (B), after (A), causes the joining target (W) to be placed at the friction stir welding machine (102) so that the first member (W1) is opposed to a distal end of a tool (10); and (C), after (B), controls a linear motion driver (7) and a rotation driver (8) so as to, while pressing the distal end of the tool (10) to the joining target (W), rotate the tool (10) around an axis, so that the softened second and third members (W2), (W3) intrude into the softened first member (W1), thus joining the joining target (W).

Abstract: A friction stir joining device includes a tool, a rotary driver, a linear-movement driver, and a control device. The control device is adapted to (A) dispose so that a first member opposes to the tool, and the first member, a second member and a third member are located in this order, (B) control the linear-movement driver and the rotary driver so that a tip-end part of the tool presses a joined part of a to-be-joined object while the tool is rotated, (C) control the linear-movement driver and the rotary driver so that the third member softened extends above an upper surface of the second member, and the tip-end part of the tool reaches a first position, and (D) control the linear-movement driver and the rotary driver so that the tool is drawn out from the joined part while the tool is rotated.

Abstract: A friction welding apparatus is provided, which includes a tool, a rotary driver, a linear driver, and a control device. The control device controls the linear driver and the rotary driver so that the tool is rotated while a tip-end part thereof is pressed against a to-be-joined part of a to-be-joined object to increase a temperature of the to-be-joined part at or above an A1 transformation point, the tip-end part of the tool reaches a given first position so that a softened second member sticks into a softened first member, and the tool is drawn out from the to-be-joined part while the tool is rotated.

Abstract: A canopy (23) is provided to rise in an upper revolving structure (3) for covering an upper side of an operator's seat (19). A bend portion (25B) extending in the left-right direction and projecting upward is provided in a front end side of a roof plate (25) in the canopy (23). A plate-shaped left front lifting bracket (26) is provided in a left front connecting portion (24J), and a plate-shaped right front lifting bracket (27) is provided in a right front connecting portion (24L). The left and right front lifting brackets (26, 27) sandwich the bend portion (25B) from both sides in the left-right direction. Further, the left and right front lifting brackets (26, 27) are provided with lifting holes (26A, 27A) and also discharging notches (26B, 27B).

Abstract: A canopy (23) is provided to rise in an upper revolving structure (3) for covering an upper side of an operator's seat (19). A bend portion (25B) extending in the left-right direction and projecting upward is provided in a front end side of a roof plate (25) in the canopy (23). A plate-shaped left front lifting bracket (26) is provided in a left front connecting portion (24J), and a plate-shaped right front lifting bracket (27) is provided in a right front connecting portion (24L). The left and right front lifting brackets (26, 27) sandwich the bend portion (25B) from both sides in the left-right direction. Further, the left and right front lifting brackets (26, 27) are provided with lifting holes (26A, 27A) and also discharging notches (26B, 27B).