| 摘要 |
<p>A hollow hole (11) is radially formed in the rotor (10) in at least one position on its circumference so that the minimum thickness between the hollow hole (11) and each of front and rear braking surfaces (12A,12B) is selected to be not larger than 3 mm. Alternatively, in a ventilated rotor (20), at least one of plural holes (21) formed radially in the rotor (20) is shaped into an expanded hole so that the minimum thickness between the hole and each of front and rear braking surfaces is selected to be not larger than 3 mm. Two rows of small (31Aa,31Ab,31Ac,31Ad - 31Ba,31Bb,31Bc) circular holes may be formed in a specific arrangement so as to penetrate a disc rotor (30). If longitudinal wave vibration is transmitted to the disc rotor (30), squeals due to an even number order resonance mode, that is, a resonance mode of the second, fourth, sixth order or the like, can be effectively attenuated by specially shaped hollow holes, reduced holes, or two rows of small circular holes formed in a disc rotor. <IMAGE></p> |
