| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a braking device part comprising a hydraulically-operated piston capable of securing lock-back action and improved in brake feeling in an initial period of braking. <P>SOLUTION: In this braking device wherein a piston 27 having a seal 41 on its outer periphery is inserted into a cylinder hole 25 formed on a brake housing 23, the piston 27 is operated by fluid pressure of a fluid pressure chamber 29 composed of one end part of the piston 27 and the brake housing 23, and a frictional member is pressed to a rotor to brake the rotor, the seal 41 is slidably kept into contact with the cylinder hole 25 at its outer peripheral part 41a, the inner peripheral part 41b is stored in a seal groove 43 formed on the piston 27, a groove width R of the seal groove 43 is larger than a width S of the seal 41, and a ring member 45 is inserted between an inner part of a side face 41c at an anti-rotor side of the seal 41 and an inner part of a wall face 43c at an anti-rotor side of the seal groove 43. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
