Seat reclining apparatus for vehicle

A seat reclining apparatus (4, 50) for a vehicle includes a first plate (21) attached to a seat cushion (2) and including an internal gear (22a), a second plate (23) attached to a seat back (3) and including an external gear (24a) engaging with the internal gear (22a), a pair of wedge members (26; 27, 51; 52) arranged between the first and second plates (21, 23), biased in a direction in which eccentricity between the internal and external gears (22a, 24a) increases, and retaining an engagement position between the internal and external gears (22a, 24a) , and a driving cam (31) relatively rotatable to the first plate (21), including a cam portion (31c), and shifting the engagement position by the cam portion (31c) that presses the wedge members (26; 27, 51; 52) so that the wedge members (26; 27, 51; 52) are integrally rotated with the cam portion (31c) when the driving cam (31) is rotatably operated. The seat reclining apparatus (4, 50) further includes a protruding column portion (30) provided in the center of the first plate (21) and a torsion spring (33) having a coil portion (33a) and both ends (33b).