| 摘要 |
<P>PROBLEM TO BE SOLVED: To easily manage an invalid stroke in a hydraulic pressure generation apparatus in which a braking function can be maintained even when an electric motor is failed. <P>SOLUTION: On the basis of the stroke of a brake pedal 20, the operation of an electric motor 22 is controlled by a controller C and a primary piston 7 is driven via a belt transmission mechanism 23 and a ball screw mechanism 24, thereby generating brake hydraulic pressure in a master cylinder 2. At such a time, the brake hydraulic pressure in a primary chamber 6A is fed back to the brake pedal 20 by a small-diameter sub piston, thereby obtaining a fixed boost ratio. When the electric motor 22 is failed, a sub piston 9 with a small pressure receiving area is directly driven via an input rod 21 by the brake pedal 20, thereby generating the brake hydraulic pressure. The sub piston 9 is abutted on the primary piston 7 and the retraction position thereof is specified. <P>COPYRIGHT: (C)2013,JPO&INPIT |
