BRAKE DEVICE

摘要

PROBLEM TO BE SOLVED: To provide a brake device capable of obtaining a proper jerk characteristic at brake operating time, capable of miniaturizing the device and capable of stably applying a safety brake and a stay brake. SOLUTION: A brake shoe is supported by a brake shoe support part 25 on the tip of a piston rod 23 of a jerk cylinder 20 provided with a jerk spring 26. This brake device is provided with a brake spring 15 for always energizing the jerk cylinder 20 in the braking direction and a brake cylinder 1 for fixing the jerk spring 20 to a tip side rod 8. Oil pressure of a releasing side oil passage 5 and a braking side oil passage 6 connected to both oil chambers 3, 4 of the brake cylinder 1 is switched by actuation of a hydraulic motor 30. A stroke of the brake cylinder 1 is locked by switching of a first solenoid valve 45. A stroke to the braking side of the brake cylinder 1 at traveling time is detected by a limit switch 51.