Akebono Brake Industry Co., Ltd.

Akebono Research and Developement Centre Ltd.

Akebond Research and Development Centre Ltd.

Toru Yoshino

Mikio Matsuzaki

Hiroshi Tokumura

Toshitaka Izumihara

Nobuo Kamioka

Yukikazu Koyanagi

A hollow hole is radially formed in a rotor in at least one position on its circumference so that the minimum thickness between an inner surface of the hollow hole and each of the front and rear braking surfaces is selected to be not larger than 3 mm. Alternatively, in a ventilated rotor, at least one of a plurality of holes formed radially in the rotor is shaped into an expanded hole so that the minimum thickness between an inner surface of the hole and each of the front and rear braking surfaces is selected to be not larger than 3 mm. Two rows of small circular holes may be formed in a specific arrangement so as to penetrate a disc rotor. If longitudinal wave vibration is transmitted to the disc rotor, 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.

Disc rotor for preventing squeal

A friction material containing dust having bismaleimidetriazine as a major ingredient. The dust is effective when contained in amount of 1 to 20 wt. % in the friction material. Compared with conventional friction material containing cashew dust, the generation rate of noise is reduced drastically, while the frictional performance is equivalent or higher.

Friction material containing BT resin dust

A device for preventing the squeak in a disc brake apparatus in which friction pads comprised of a semi-metallic or a non-asbestos material are pushed onto a disc rotor to perform braking is characterized in that the disc rotor is circumferentially divided by the use of slits or couplings so that the frequency of second-order resonance in the longitudinal vibration of the rotor is higher than 15 kHz and thus inaudible to humans.

Squeak prevention for disc brake

Method of processing brake pads having a lining member mounted on a back plate is disclosed. An exposed surface of the lining member initially having a substantially planar configuration is heated to a warping temperature between substantially 300.degree. C. and substantially 800.degree. C. to be permanently warped the brake pad into a substantially concave configuration. Then the exposed surface of the lining member is ground into a substantially planar configuration, while maintaining the warped condition of the brake pad.

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Gyoda, Japan

Toru Yoshino