| 摘要 |
<p>PURPOSE:To reduce the number of parts of the captioned device by providing an ultrasonic motor which operates in company with the operation of a brake operating element in order to push a pushing member against a piston and which stops as soon as the operation of the brake operating element is released in order to make the pushing member cease to push the piston. CONSTITUTION:When a driver depresses a brake pedal, a voltage is impressed to a piezoelectric body of an ultrasonic motor 9 in order to generate a progressive wave in an elastic rail. As a result, since the mass point conducts elliptical movement, a rod 8 rotates in the predetermined direction. As the rod 8 rotates, a pushing member 6 goes straight toward a piston 2 in order to push the piston 2. As a result, the piston 2 pushes a pad 4 on the piston (2) side, while a caliper 1 slightly moves toward the left. Thus, a rotor 5 is pushed and interposed by a pair of pads 4 and 4. Accordingly, a brake can be put on the rotor 5. In this case, the braking force can be varied, according to the variation in the driver's depressing force to the brake pedal.</p> |
