| 摘要 |
PROBLEM TO BE SOLVED: To suppress the eccentric wear of a friction material 52 of a brake pad 51, in a brake disc rotor 10 in which a groove 30 is formed at a slide face 25.SOLUTION: A plane shape of a groove 30 is formed into a spiral shape which is expressed by a Bernoulli's spiral equation, and a cross section shape of the groove 30 is formed into a V-shape which is downwardly inclined toward a width direction center side at a constant inclination angle. By this constitution, a cross section advance angle of the groove 30 with respect to a friction member 52 becomes constant at any point of the friction material 52, and the wear of the friction material 52 becomes uniform. Furthermore, a length of the groove 30 is set so that a portion extruded from a pressing region of the friction material 52 always exists irrespective of a relative position of the slide face 25 and the brake pad 51. Thus, the groove 30 is not sealed by the friction material 52, and the generation of noise can be prevented. |
