Seat reclining apparatus for vehicle

摘要

A seat reclining apparatus for a vehicle includes a first arm including a guide wall, a second arm including internal teeth and being rotatably supported by the first arm, a pawl including external teeth which are engageable with and disengageable from the internal teeth, a cam engaging with the pawl for causing the pawl to advance and retract along a guide wall and for causing the internal teeth and the external teeth to mesh with and unmesh from each other as the cam rotates, a recessed portion recessed in a direction of an axis line of the second arm and including a restricting portion, an engaging portion restricting the external teeth and the internal teeth from meshing with each other by being in contact with the restricting portion, a hinge cam including a first shaft portion, a second shaft portion and a flange portion, and a biasing member.

主权项

1. A seat reclining apparatus for a vehicle, comprising:
a first arm configured to be fixedly attached to one of a seat cushion and a seatback, the first arm including a guide wall; a second arm configured to be fixedly attached to the other one of the seat cushion and the seatback, the second arm including internal teeth and being rotatably supported by the first arm; a pawl arranged in an accommodating space formed between the first arm and the second arm, the pawl including external teeth which are engageable with and disengageable from the internal teeth, the pawl being arranged in a manner that movement of the pawl in a radial direction of the first arm is guided by the guide wall; a cam rotatably arranged in the accommodating space at a radially inner side relative to the pawl, the cam engaging with the pawl, causing the pawl to advance and retract along the guide wall, and causing the internal teeth and the external teeth to mesh with and unmesh from each other as the cam rotates; a recessed portion provided at the second arm concentrically with the internal teeth in a manner that the recessed portion is recessed in a direction of an axis line of the second arm, the recessed portion including a restricting portion provided in a range of a predetermined angle and protruding inwardly in a radial direction of the second arm; an engaging portion formed at the pawl in a manner that the engaging portion faces the recessed portion in a radial direction of the pawl at a position different, in the direction of the axis line, from an engagement position at which the pawl and the cam engage with each other, the engaging portion restricting the external teeth and the internal teeth from meshing with each other by being in contact with the restricting portion; a hinge cam integrally rotatably fitted in the cam by insertion in the direction of the axis line, and including a first shaft portion, a second shaft portion and a flange portion, the first shaft portion penetrating through the first arm and rotatably supported at the first arm, the second shaft portion penetrating through the second arm and journaled at the second arm, the flange portion being accommodated in a space defined by the recessed portion at a radially inner side relative to the engaging portion; a biasing member biasing and rotating the hinge cam at the first shaft portion in one direction and causing via the cam the pawl to move in a radial direction in which the external teeth and the internal teeth mesh with each other or in which the engaging portion and the restricting portion are in contact with each other, wherein the first arm, the second arm, the pawl, the cam, the hinge cam and the biasing member are arranged at each side in a seat width direction in a manner that the first arm, the second arm, the pawl, the cam, the hinge cam and the biasing member are provided as pairs; a hinge pin fitted in each hinge cam by insertion in the direction of the axis line and rotating integrally with the corresponding hinge cam; an operation member integrally rotatably connected to one of the hinge pins and inputting a releasing operation force to the hinge pin; a connecting member integrally rotatably connected to the hinge pin arranged at each side in the seat width direction and transmitting a rotation of one of the hinge pins to the other one of the hinge pins as the releasing operation force is inputted; and a play provided at at least one of between each cam and each hinge cam and between each hinge cam and each hinge pin, the play being provided in a circumferential direction and in a radial direction of the hinge cam while being centered with respect to the direction of the axis line.