Abstract: In a friction spot joint structure, a first plate member is pressed against a second plate member by using a rotary tool and a receiving member. A concave portion is formed by a rotating pin portion of the rotating tool, with an interface between the first plate member and the second plate member remained. In this time, the first and second plate members are allowed to plastic-flow, so that an annular bulging portion of the second plate member raised into the first plate member is formed around the concave portion.

Abstract: An aluminum plate and a steel plate are lapped. A rotating tool is placed on the aluminum plate, and then a pressing force and a rotational force around a pressing axis of the rotating tool are applied to the aluminum plate and the steel plate. A zinc plating layer having oxidation-prevention function is formed on the surface of the steel plate in advance. When joining the both plates, an oxidation film formed on the aluminum plate is destroyed and the zinc plating layer is pushed out outward from a joining portion, by applying the above pressing force and frictional heat and plastic flow due to the rotation of the rotating tool. Thereby, respective new uncovered surfaces of the both plates are directly contacted.

Abstract: In a friction spot joint structure, a first plate member is pressed against a second plate member by using a rotary tool and a receiving member. A concave portion is formed by a rotating pin portion of the rotating tool, with an interface between the first plate member and the second plate member remained. In this time, the first and second plate members are allowed to plastic-flow, so that an annular bulging portion of the second plate member raised into the first plate member is formed around the concave portion.

Abstract: In a friction spot joint structure, a first plate member is pressed against a second plate member by using a rotary tool and a receiving member. A concave portion is formed by a rotating pin portion of the rotating tool, with an interface between the first plate member and the second plate member remained. In this time, the first and second plate members are allowed to plastic-flow, so that an annular bulging portion of the second plate member raised into the first plate member is formed around the concave portion.

Abstract: An aluminum plate and a steel plate are lapped. A rotating tool is placed on the aluminum plate, and then a pressing force and a rotational force around a pressing axis of the rotating tool are applied to the aluminum plate and the steel plate. A zinc plating layer having oxidation-prevention function is formed on the surface of the steel plate in advance. When joining the both plates, an oxidation film formed on the aluminum plate is destroyed and the zinc plating layer is pushed out outward from a joining portion, by applying the above pressing force and frictional heat and plastic flow due to the rotation of the rotating tool. Thereby, respective new uncovered surfaces of the both plates are directly contacted.

Abstract: A spot joining device comprises a joining tool, an induction motor for rotating the joining tool, a servo motor for vertically moving the joining tool along an axis of the joining tool, and a receiving member placed opposite to the joining tool. The joining tool includes a short-column shaped shoulder and a pin protruded downwardly along the axis from a central portion of a lower face of the shoulder at a tip end portion thereof. Two works such as aluminum alloy plates are lapped and placed on a receiving member. When the joining tool is rotated and moved downwardly, a joint spot of the works is heated and softened due to friction heat generated by the rotating pin. Thereby, plastic flow occurs in the vicinity of the joint spot. The vicinity of the joint spot is stirred and the works are fused at the joint spot. Thus, the works are spot-joined.

Abstract: At least two materials are superposed and a rotary tool 1 is pressed on a first material W1 at an outermost surface, whereby metal texture between the superposed first and second materials W1, W2 is agitated by frictional heat in a melting condition to join the materials.

Abstract: A spot joining device comprises a joining tool, an induction motor for rotating the joining tool, a servo motor for vertically moving the joining tool along an axis of the joining tool, and a receiving member placed opposite to the joining tool. The joining tool includes a short-column shaped shoulder and a pin protruded downwardly along the axis from a central portion of a lower face of the shoulder at a tip end portion thereof. Two works such as aluminum alloy plates are lapped and placed on a receiving member. When the joining tool is rotated and moved downwardly, a joint spot of the works is heated and softened due to friction heat generated by the rotating pin. Thereby, plastic flow occurs in the vicinity of the joint spot. The vicinity of the joint spot is stirred and the works are fused at the joint spot. Thus, the works are spot-joined.

Abstract: At least two materials are superposed and a rotary tool 1 is pressed on a first material W1 at an outermost surface, whereby metal texture between the superposed first and second materials W1, W2 is agitated by frictional heat in a melting condition to join the materials.