| 摘要 |
PROBLEM TO BE SOLVED: To provide a drum brake capable of preventing the over-adjustment of a shoe clearance by stopping an automatic adjustment operation for shoe clearance when a temperature of a brake drum is increased, preventing the impairing of operation feeling of the brake by reducing the shoe clearance, and securing the quick braking effect. SOLUTION: This drum brake comprises a retraction control device (shoe clearance adjusting strut 131) for automatically determining the shoe clearance by displacing a pair of brake shoes 10, 15 in the expanding direction, a temperature sensitive member 35 is mounted to energize the retraction control device in the direction to stop the shoe clearance automatic adjusting operation when a temperature reaches a predetermined temperature to prevent the over-adjustment of the shoe clearance, and the action force in the expanding direction of both brake shoes 10, 15 in accompany with the thermal deformation of the temperature sensitive member 35 is determined to be more than the return force of the brake shoes 10, 15 obtained by the spring force of shoe return springs 7, 8 and an adjust spring 38. COPYRIGHT: (C)2004,JPO
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