Safety braking mechanism

The utility model relates to the technical field of braking devices, and discloses a safety braking mechanism which solves the problems that in the braking process of an existing automobile, an involute curved surface of a driving shaft is in linear contact with a curved surface of a roller, abrasion is fast, and the braking effect is poor. A hydraulic device is mounted at the bottom of a cavity of the mounting box, an ejector rod is sleeved with the hydraulic device, the top end of the ejector rod is connected with a toothed plate, the top end of the toothed plate penetrates through the mounting box and is fixedly connected with the bottom end of a first movable plate, a first gear and a second gear are mounted on the two sides of the toothed plate respectively, and a first toothed rod meshed with the first gear is mounted on the side, away from the toothed plate, of the first gear. The side, away from the toothed plate, of the second gear is provided with a second toothed bar meshed with the second gear. An