Locking apparatus of seat belt buckle for vehicle

1. A locking apparatus of a buckle of a seat belt for vehicles, comprising:

a sector gear bracket configured to be integrally coupled to a rear pipe which is coupled to a seat cushion frame, wherein the sector gear bracket has:

an arc-shaped locking hole; and

a sector gear arranged along the locking hole as an internal gear;

a pole bracket located at one side of the sector gear bracket, wherein the pole bracket has a shaft part which is configured to pass through the locking hole and the seat cushion frame and then be integrally coupled to a lower end of the buckle;

a lock gear arranged on an outer surface of the pole bracket as an external gear;

a patch bracket fixedly coupled to one surface of the seat cushion frame, which is disposed to face the sector gear bracket; and

a guide hole, through which the shaft part passes, extending through the seat cushion frame and the patch bracket,

wherein, when the shaft part is coupled to the buckle, the lock gear is configured to be disposed in the locking hole and configured to move in the locking hole in a diagonal direction due to a load applied to the buckle so as to be engaged with or disengaged from the sector gear.

2. The locking apparatus according to claim 1 , wherein the guide hole has a shape of a slit oriented in a diagonal direction in which the load is applied to the buckle.

3. The locking apparatus according to claim 1 , wherein, when the shaft part moves upwards along the guide hole due to the load applied to the buckle, the lock gear is engaged with the sector gear, and

wherein, when the shaft part moves downwards along the guide hole, the lock gear is disengaged from the sector gear.

4. The locking apparatus according to claim 1 , further comprising:

a rail bracket to which a front end of the sector gear bracket is rotatably coupled by a hinge pin; and

a seat rail to which the rail bracket is fixedly coupled,

wherein, when a collision occurs, the load applied to the buckle is transmitted to a vehicle body through the sector gear bracket, the hinge pin, the rail bracket and the seat rail.

5. The locking apparatus according to claim 1 , wherein the seat cushion frame and the seat rail are connected by a plurality of rotatable links,

wherein, when the seat cushion frame and the rear pipe vertically move with respect to the seat rail, the seat cushion frame vertically moves due to rotation of the rotatable links so that a height of the seat cushion frame is adjusted, and

wherein, when the seat cushion frame vertically moves, the buckle connected to the seat cushion frame vertically moves together with the seat cushion frame.

6. The locking apparatus according to claim 1 , wherein, when the lower end of the buckle and the shaft part of the pole bracket are coupled to each other, a spring bracket is integrally coupled thereto,

wherein the locking apparatus further comprises a return spring having one end supported by the spring bracket and another end supported by the seat cushion frame, and

wherein the return spring is configured to transmit a spring force to the spring bracket such that the lock gear is spaced apart from the sector gear so as to release engagement between the lock gear and the sector gear.

7. The locking apparatus according to claim 1 , further comprising:

a bolt part configured to protrude towards the pole bracket on the patch bracket; and

a bracket hole, through which the bolt part passes, defined in the pole bracket in a same diagonal direction as the guide hole,

wherein, a pole nut is coupled to the bolt part having passed through the bracket hole, such that when the shaft part moves along the guide hole by the load applied to the buckle, torsion of the pole bracket is prevented.

8. The locking apparatus according to claim 1 , wherein the buckle of the seat belt is connected to the seat cushion frame and the seat rail by the locking apparatus.