Abstract: A welded structure has a first member and a second member that are welded together. The first member comprises a second-member joining part, and the second member comprises a first-member joining part. If the direction in which the first member and the second member are arranged is the first direction, and the direction intersecting the first direction is the second direction, welded parts are provided at least at both ends in the second direction of the joining surface where the first member and the second member are joined. The first member is such that the second-member joining part and a linking part which connects to the second-member joining part are arranged in succession from the joining surface in the first direction, and the dimensions of the second-member joining part are greater than the dimensions of the linking part in a third direction perpendicular to the first direction.

Abstract: Disclosed is a caulking tool used for a ring gear press-fit in the outer periphery of a flange of a differential case constituting a differential subassembly, in order to caulk a caulking portion provided on at least either end of the flange in the axial direction, with respect to a plurality of notches formed in at least either end of the ring gear in the axial direction. The notches are formed along the inner periphery of the ring gear. Each notch has a bottom part slanted at a predetermined angle with respect to the radial direction of the ring gear, and a plurality of protrusions which correspond to the notches and are projected from the slant portion, in order to press the caulking portion in the axial direction of the ring gear.

Abstract: A fastening structure for a ring-gear and a differential case comprises a differential case which is provided with: a ring gear having a gear section formed on the outer peripheral surface thereof, and a plurality of notch portions formed on the inner peripheral surface thereof; a press-fitting surface whereon the ring gear is press-fitted; and a flange section which is forced against and caulked to the notch portions, at the end of the press-fitting surface. After the ring gear has been press-fitted to the press-fitting surface, the flange section is forced toward the notch portions, and thus the differential case is caulked and fastened to the ring gear. The notch portions have stepped surfaces , and thus rattling generated during torque transmission can be suppressed.

Abstract: A welded structure and welding method make it possible to improve welding strength and welding quality. A welded structure in which a first member and a second member are joined by welding, wherein the first member comprises a second-member joining part which is joined to the second member, and the second member comprises a first-member joining part which is joined to the first member. If the direction in which the first member and the second member are arranged is the first direction, and the direction intersecting the first direction is the second direction, the welded structure comprises a cavity part which is provided between the first-member joining part and the second-member joining part, and a welded part which is provided between the cavity part and both end parts in the second direction of the joining surface where the first-member joining part and the second-member joining part are joined.

Abstract: A welding structure includes: an annular ring gear including a gear portion and a gear joint; and a case including a case joint joined to the gear joint, the welding structure being configured to fix the ring gear to the case by welded portions formed on both ends in an axial direction of the ring gear so that a gear-side weld surface of the gear joint and a case-side weld surface of the case joint are welded to each other. In the welded portion on at least one side in the axial direction is placed more outside than a gear end face of the gear portion in the axial direction. Alternatively, in the welded portion on at least one side in the axial direction, the gear-side weld surface and the case-side weld surface are inclined with respect to the axial direction.

Abstract: Disclosed is a caulking tool used for a ring gear press-fit in the outer periphery of a flange of a differential case constituting a differential subassembly, in order to caulk a caulking portion provided on at least either end of the flange in the axial direction, with respect to a plurality of notches formed in at least either end of the ring gear in the axial direction. The notches are formed along the inner periphery of the ring gear. Each notch has a bottom part slanted at a predetermined angle with respect to the radial direction of the ring gear, and a plurality of protrusions which correspond to the notches and are projected from the slant portion, in order to press the caulking portion in the axial direction of the ring gear.

Abstract: A fastening structure for a ring-gear and a differential case comprises a differential case which is provided with: a ring gear having a gear section formed on the outer peripheral surface thereof, and a plurality of notch portions formed on the inner peripheral surface thereof; a press-fitting surface whereon the ring gear is press-fitted; and a flange section which is forced against and caulked to the notch portions, at the end of the press-fitting surface. After the ring gear has been press-fitted to the press-fitting surface, the flange section is forced toward the notch portions, and thus the differential case is caulked and fastened to the ring gear. The notch portions have stepped surfaces, and thus rattling generated during torque transmission can be suppressed.

Abstract: Disclosed is a structure for fastening a ring gear to a differential case. The ring gear has a gear-side press-fit face annularly formed thereon, a projected portion located at an inner position relative to the gear-side press-fit face, and a notch portion located opposite to the gear-side press-fit face across the projected portion. The differential case has a case-side press-fit face which is annularly formed thereon and over which the gear-side press-fit face is press fitted, a caulk portion which is smaller than the case-side press-fit face in outer diameter and caulked to the notch portion, and a case-side smooth face which contacts the projected portion to position the ring gear with respect to the differential case. This arrangement serves to reduce the differential case in size.

Abstract: Disclosed are a welded structure and a welding method which make it possible to improve welding strength and welding quality. A welded structure in which a first member and a second member are joined by means of welding, wherein the first member comprises a second-member joining part which is joined to the second member, and the second member comprises a first-member joining part which is joined to the first member. If the direction in which the first member and the second member are arranged is the first direction, and the direction intersecting the first direction is the second direction, welded parts are provided at least at both ends in the second direction of the joining surface where the first member and the second member are joined.

Abstract: Disclosed are a welded structure and a welding method which make it possible to improve welding strength and welding quality. A welded structure in which a first member and a second member are joined by means of welding, wherein the first member comprises a second-member joining part which is joined to the second member, and the second member comprises a first-member joining part which is joined to the first member. If the direction in which the first member and the second member are arranged is the first direction, and the direction intersecting the first direction is the second direction, the welded structure comprises a cavity part which is provided between the first-member joining part and the second-member joining part, and a welded part which is provided between the cavity part and both end parts in the second direction of the joining surface where the first-member joining part and the second-member joining part are joined.