| 摘要 |
<p>PURPOSE:To prevent lowering of power performance of a vehicle and early abrasion of a pad by setting a slide resistance of a second piston with a second seal part smaller than a slide resistance of a brake piston with a first seal part. CONSTITUTION:When the fluid pressure for braking is flowed into cylinders 2, 3, pistons 4, 8 receive that pressure to progress together. But, since the second piston 8 abuts on a stopper 11 to be stopped on the way, only the brake piston 4 applies the pushing pressure to friction pads 5, 6. Next, when the brake is cancelled, a ring spring 12 compressed at the time of braking is restored to push back the first piston 8 by a constant quantity, and the brake piston 4 having a slide resistance against the piston 8 is pulled back together. At this stage, when the residual pressure exist in the cylinders 2, 3 and the pad 5 is pushed to the arrow direction by the oscillation of a rotor D in the axial direction, the second piston 8 of the cylinder 2 side is pushed to the arrow direction with the brake piston 4 of the inside to lower the axial tension between the rotor D and the pad 5.</p> |
