| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a disk brake capable of reducing the return of a piston in the direction of a hydraulic pressure chamber due to the thermal expansion of a seal member by using the seal member of square shape in cross section capable of stably providing roll back performance. <P>SOLUTION: This disk brake uses the seal member 11 of square shape in cross section capable of stably providing roll back performance. Also, a peripheral surface part 14e having a diameter increasing toward the bottom part 8a of a cylinder bore 8 is formed on the bottom surface part 14c of a seal groove 14, and the expanded portion 14g of the seal member 14 expanded by heat faces the peripheral surface part 14e. Thus, the volumetric change of the seal member when expanded by heat can be absorbed by the peripheral surface part, the volumetric change of the inner peripheral surface 14a of the seal member 14 can be suppressed, and the amount of the movement of the piston 10 in the direction of the hydraulic pressure chamber can be reduced. <P>COPYRIGHT: (C)2004,JPO</p> |
