Vehicle seat reclining device

Abstract

A vehicle seat reclining device is provided with: a first bracket having internal teeth; a plurality of pawls each having external teeth capable of engaging with and disengaging from the internal teeth; a second bracket having a guide part that movably holds the plurality of pawls in a radial direction; and a cam mechanism which moves each of the pawls in the radial direction. Among the external teeth in each of the pawls, at least one external tooth including an end tooth located at one end in the circumferential direction of the pawl is displaced inward in the radial direction with respect to a reference position corresponding to the pitch circle of the internal teeth along a center line that divides the external tooth into two parts in the circumferential direction without changing the shape of an effective engagement portion for the internal tooth and the pitch circle radius of the external tooth.

Description

technical field [0001] The present invention relates to a vehicle seat reclining device. Background technique [0002] A vehicle seat generally includes a reclining device capable of adjusting a tilting angle of a seat back relative to a seat cushion. [0003] For example, the reclining device described in Patent Document 1 includes: a first bracket (tooth plate) having internal teeth on an annular inner periphery; and a second bracket (base plate) having a guide portion for holding the above-mentioned ratchet so as to be movable in the radial direction, and the second bracket is relatively rotatable with respect to the first bracket. In addition, the reclining device includes a cam mechanism having a cam body disposed radially inside the plurality of pawls, and the cam mechanism is configured to move each pawl in the radial direction as the cam body rotates. , so that the outer teeth of each pawl engage and separate from the inner teeth of the first bracket. One of the f...

AI Technical Summary

Problems solved by technology

On the other hand, in order to compensate for the reduction in locking strength due to miniaturization, the number of external teeth of each pawl that meshes with the internal teeth is increased, but the pressure angle between the internal teeth and the external teeth is reduced accordingly.

Therefore, in the prior art as described above, it is difficult to smoothly unlock the outer teeth with respect to the inner teeth while keeping the detachability of the outer teeth well, and there is still room for further improvement in this point.