A recliner includes a first and second connecting members assembled together, and a ring member that holds the assembled connecting members. A dowel fitted in a fitting portion of a frame is formed in a region of an axially outer surface of the second connecting member. A radially outer portion of the second connecting member has an expanded portion expanding radially outward in a region at a circumferential position where the dowel is formed, and a recessed portion recessed radially inward in a region at a circumferential position where the dowel is not formed. A joint portion of the ring member is placed on an outer circumferential surface of the recessed portion, and the expanded portion is placed, from an inside in the axial direction, against a weld zone of the frame in which the dowel is welded.
1. A recliner that connects a seat back to a base on a floor such that a backrest angle of the seat back is adjustable, the recliner comprising:
a first disk shaped connecting member and a second disk shaped connecting member assembled in an axial direction such that the first connecting member and the second connecting member are rotatable relative to each other;
a rotation inhibiting mechanism that is provided between the first connecting member and the second connecting member and inhibits relative rotation of the first connecting member and the second connecting member; and
a ring member that is mounted across radially outer portions of the first connecting member and the second connecting member and holds the first connecting member and the second connecting member assembled in the axial direction, wherein the ring member has a retaining portion placed against the radially outer portion of the first connecting member, from an outside in the axial direction, and a joint portion joined to the radially outer portion of the second connecting member;
a dowel fitted in a fitting portion of a frame that constitutes one of the seat back and the base is provided in a region of an axially outer surface of the second connecting member, the dowel protruding from the axially outer surface;
the radially outer portion of the second connecting member has an expanded portion that expands radially outward beyond the dowel in a region at a circumferential position where the dowel is provided, and has a recessed portion that is recessed radially inward relative to the expanded portion in a region at a circumferential position where the dowel is not provided;
the recessed portion receives the joint portion of the ring member in the axial direction, and the joint portion of the ring member is placed on an outer circumferential surface of the recessed portion; and
the expanded portion expands radially outward beyond the joint portion of the ring member placed on the outer circumferential surface of the recessed portion, and is placed, from an inside in the axial direction, against a weld zone of the frame in which the dowel fitted in the fitting portion is welded from the outside in the axial direction.
2. The recliner according to claim 1 , wherein:
the first connecting member has an internal gear formed by half-blanking on an axially outer side of a central portion of the first connecting member;
the second connecting member has an external gear formed by half-blanking on an axially inner side of a central portion of the second connecting member;
the external gear meshes with the internal gear and rotates relative to the internal gear while changing a mesh position where the external gear meshes with the internal gear; and
the dowel is provided in the region located on a radially outer side of the external gear.
3. The recliner according to claim 1 , wherein the expanded portion determines a mounting position of the ring member when the ring member is butted against the expanded portion in the axial direction.