Abstract: A tool driving section of a friction stir spot welding device is configured to advance and retract each of a pin member and a shoulder member. A tool driving control section is configured to control the tool driving section such that an absolute value of a tool average position Tx is small, wherein Tx is defined by a following equation: Ap·Pp+As·Ps=Tx, where Ap is a cross-section area of a front end surface of the pin member, As is a cross-section area of a front end surface of the shoulder member, Pp is a press-fit depth of the pin member press-fitted from a front surface of an object to be welded, and Ps is a press-fit depth of the shoulder member press-fitted from the front surface of the object to be welded. Thus, especially in a double-acting friction stir spot welding, excellent welding quality can be accurately achieved according to welding conditions, and an internal cavity defect can be prevented or suppressed.

Abstract: A tool driving section of a friction stir spot welding device is configured to advance and retract each of a pin member and a shoulder member. A tool driving control section is configured to control the tool driving section such that an absolute value of a tool average position Tx is small, wherein Tx is defined by a following equation: Ap·Pp+As·Ps=Tx, where Ap is a cross-section area of a front end surface of the pin member, As is a cross-section area of a front end surface of the shoulder member, Pp is a press-fit depth of the pin member press-fitted from a front surface of an object to be welded, and Ps is a press-fit depth of the shoulder member press-fitted from the front surface of the object to be welded. Thus, especially in a double-acting friction stir spot welding, excellent welding quality can be accurately achieved according to welding conditions, and an internal cavity defect can be prevented or suppressed.

Abstract: A tool driving section of a friction stir spot welding device is configured to advance and retract each of a pin member and a shoulder member. A tool driving control section is configured to control the tool driving section such that an absolute value of a tool average position Tx defined by a following equation: Ap·Pp+As·Ps=Tx, where Ap is a cross-section area of a front end surface of the pin member, As is a cross-section area of a front end surface of the shoulder member, Pp is a press-fit depth of the pin member press-fitted from a front surface of an object to be welded, and Ps is a press-fit depth of the shoulder member press-fitted from the front surface of the object to be welded, is small.

Abstract: A dissimilar material joint is formed by arranging a plurality of joint segments consecutively in a longitudinal direction. Each joint segment is formed by joining and integrating together a first member, an intermediate member, and a second member by explosive welding. A groove is formed in a joint end face of each joint segment, the joint end face being joined to another one of the segments, the groove spacing apart an end face of the first member and an end face of the second member from each other in a stacking direction. In the dissimilar material joint, the end faces of the respective first members of the joint segments that are adjacent to each other are joined together by welding, and the end faces of the respective second members of the joint segments that are adjacent to each other are joined together by welding.

Abstract: A tool driving section of a friction stir spot welding device is configured to cause each of a pin member and a shoulder member to advance and retract, and is controlled by a tool driving control section. A press-fit reference point setting section sets a position where the pin member or the shoulder member contacts an object to be welded as a press-fit reference point, and the tool driving control section controls the position of the pin member with respect to the shoulder member on the basis of the press-fit reference point, thereby controlling the press-fit depth of a rotating tool press-fitted from the surface of the object to be welded. This achieves the excellent welding quality at suitable precision according to welding conditions especially in a double-acting friction stir spot welding method.

Abstract: A friction stir welding method in which a welding tool rotating around an axis is pressed against a welding target portion of workpieces supported by a backing member so that frictional heat is generated and the friction heat softens the welding target portion. The welding tool is at least partially inserted into the softened welding target portion and stirs the softened welding target portion so that the welding target portion is stir welded in a solid phase state. The friction stir welding method includes detecting a temperature of a temperature measurement point provided in the backing member, and calculating an estimated temperature of the welding tool from the detected temperature of the temperature measurement point, based on a predefined correlation between a temperature of the welding tool and a temperature of the backing member.

Abstract: A dissimilar material joint is formed by arranging a plurality of joint segments consecutively in a longitudinal direction. Each joint segment is formed by joining and integrating together a first member, an intermediate member, and a second member by explosive welding. A groove is formed in a joint end face of each joint segment, the joint end face being joined to another one of the segments, the groove spacing apart an end face of the first member and an end face of the second member from each other in a stacking direction. In the dissimilar material joint, the end faces of the respective first members of the joint segments that are adjacent to each other are joined together by welding, and the end faces of the respective second members of the joint segments that are adjacent to each other are joined together by welding.

Abstract: A tool driving section of a friction stir spot welding device is configured to cause each of a pin member and a shoulder member to advance and retract, and is controlled by a tool driving control section. A press-fit reference point setting section sets a position where the pin member or the shoulder member contacts an object to be welded as a press-fit reference point, and the tool driving control section controls the position of the pin member with respect to the shoulder member on the basis of the press-fit reference point, thereby controlling the press-fit depth of a rotating tool press-fitted from the surface of the object to be welded. This achieves the excellent welding quality at suitable precision according to welding conditions especially in a double-acting friction stir spot welding method.

Abstract: A tool driving section of a friction stir spot welding device is configured to advance and retract each of a pin member and a shoulder member. A tool driving control section is configured to control the tool driving section such that an absolute value of a tool average position Tx defined by a following equation: Ap·Pp+As·Ps=Tx, where Ap is a cross-section area of a front end surface of the pin member, As is a cross-section area of a front end surface of the shoulder member, Pp is a press-fit depth of the pin member press-fitted from a front surface of an object to be welded, and Ps is a press-fit depth of the shoulder member press-fitted from the front surface of the object to be welded, is small.

Abstract: A friction stir welding method in which a welding tool rotating around an axis is pressed against a welding target portion of workpieces supported by a backing member so that frictional heat is generated and the friction heat softens the welding target portion. The welding tool is at least partially inserted into the softened welding target portion and stirs the softened welding target portion so that the welding target portion is stir welded in a solid phase state. The friction stir welding method includes detecting a temperature of a temperature measurement point provided in the backing member, and calculating an estimated temperature of the welding tool from the detected temperature of the temperature measurement point, based on a predefined correlation between a temperature of the welding tool and a temperature of the backing member.

Abstract: A friction stir welding apparatus includes: a thermocouple and a temperature measurement device which are configured to detect a temperature of the temperature measurement point; a temperature monitor configured to calculate an estimated temperature of the welding tool from the detected temperature of the temperature measurement point, based on a predefined correlation between a temperature of the welding tool and a temperature of the backing member; and a controller configured to perform a predetermined procedure based on the estimated temperature of the welding tool so as to prevent overheating of the welding tool.

Abstract: A friction stir welding apparatus includes: a thermocouple and a temperature measurement device which are configured to detect a temperature of the temperature measurement point; a temperature monitor configured to calculate an estimated temperature of the welding tool from the detected temperature of the temperature measurement point, based on a predefined correlation between a temperature of the welding tool and a temperature of the backing member; and a controller configured to perform a predetermined procedure based on the estimated temperature of the welding tool so as to prevent overheating of the welding tool.

Abstract: A dissimilar joint structure according to the present invention is provided at a first metal member and a second metal member which are made of dissimilar metals to each other. The dissimilar joint structure couples the first metal member and the second metal member 7. An inserting groove 8a is formed at the first metal member. The second metal member includes an inserting portion which is able to be inserted into the inserting groove. The first metal member is joined to the inserting portion 9 with the inserting portion 9 inserted into the inserting groove 8a.

Abstract: The apparatus includes a welding head having a welding tool to be pressed against workpieces and a rotation drive unit to drive the welding tool to be rotated; a head drive unit to drive the welding head to be displaced, the head drive unit including a cylinder actuator having a piston rod to which the welding head is attached; a first pressure unit to supply a pressure fluid into a first chamber of the cylinder actuator; a second pressure unit to supply a pressure fluid into a second chamber of the cylinder actuator; a control unit to control pressures of respective pressure fluids supplied by the first pressure unit and the second pressure unit.

Abstract: A friction stir welding machine is provided that is adapted to perform solid phase welding on a welding portion of materials to be welded, by pressing a welding tool against the welding portion of the materials to be welded while rotating the welding tool, and forcing the welding tool to be advanced into a softened portion which is softened by a frictional heat while stirring the softened portion, wherein a coating made of aluminum nitride is formed on at least a region of the welding tool to be in contact with the materials to be welded.

Abstract: A friction stir welding machine is provided that is adapted to perform solid phase welding on a welding portion of materials to be welded, by pressing a welding tool against the welding portion of the materials to be welded while rotating the welding tool, and forcing the welding tool to be advanced into a softened portion which is softened by a frictional heat while stirring the softened portion, wherein a coating made of aluminum nitride is formed on at least a region of the welding tool to be in contact with the materials to be welded.

Abstract: A lightweight, mobile friction stir welding machine, a sticking pad for the friction stir welding machine, and a friction stir welding system are provided. The sticking pad has a flat base member facing an object, an annular sealing member protruding from one of major surfaces of the base member so as to surround a central area of the surface of the base member, a slippery member attached to the end surface of the annular sealing member facing the object, and one or some deformation-suppressing protrusions protruding from the surface facing the object of the base member. The slippery member is made of a material that can make the slippery member contact the object with a friction coefficient lower than that with which the sealing member can be in contact with the same object.

Abstract: The present invention is a friction stir welding machine adapted to perform solid phase welding on a welding portion of materials to be welded, by pressing a welding tool against the welding portion of the materials to be welded while rotating the welding tool, and forcing the welding tool to be advanced into a softened portion which is softened by a frictional heat while stirring the softened portion, wherein a coating made of aluminum nitride is formed on at least a region of the welding tool to be in contact with the materials to be welded.

Abstract: A dissimilar joint structure 10 according to the present invention is provided at a first metal member 6 and a second metal member 7 which are made of dissimilar metals to each other. The dissimilar joint structure 10 couples the first metal member 6 and the second metal member 7. An inserting groove 8a is formed at the first metal member 6. The second metal member 11 includes an inserting portion 9 which is able to be inserted into the inserting groove 8a. The first metal member 6 is joined to the inserting portion 9 with the inserting portion 9 inserted into the inserting groove 8a.

Abstract: A lightweight, mobile friction stir welding machine, a sticking pad for the friction stir welding machine, and a friction stir welding system are provided. The sticking pad has a flat base member facing an object, an annular sealing member protruding from one of major surfaces of the base member so as to surround a central area of the surface of the base member, a slippery member attached to the end surface of the annular sealing member facing the object, and one or some deformation-suppressing protrusions protruding from the surface facing the object of the base member. The slippery member is made of a material that can make the slippery member contact the object with a friction coefficient lower than that with which the sealing member can be in contact with the same object.