Locking apparatus of seat belt buckle for vehicle

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;
• and
• a lock gear arranged on an outer surface of the pole bracket as an external gear,
• 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.