Nichias Corporation

Seiji Sakurada

Takahiro Niwa

Kunihiko Yano

Masaki Yoshihara

In order to provide a shim for preventing brake squeal in a disk brake, which can decrease high frequency noise (squealing phenomena) produced at braking, a rubber coated metal, in which a rubber layer is disposed on one surface of a metal plate is used and a pressure sensitive adhesive layer is disposed directly on the other surface of the metal plate, the pressure sensitive adhesive layer may include a primer layer on the other surface of the metal plate. The pressure sensitive adhesive layer of this shim structure serves as an adhesive portion to be stuck to a backplate of a disk brake pad. Since the pressure sensitive adhesive layer is disposed on the metal plate, the pressure sensitive adhesive layer is never peeled off from the rubber coated metal and its damping action (brake squeal preventing action) is maintained.

Shim for preventing brake squeal in a disk brake

A vibration damping material represents a high vibration damping property (loss factor .eta.) in a plurality of temperature ranges. A viscoelastic material layer between two constraining plates or between a constraining plate and a vibrating body is in the form of a bubble-contained adhesive layer containing bubbles. Near the glass transitional point (Tg), the bubble-contained adhesive layer is changed from a glass status to a rubber status and represents a first peak of the loss factor. In a temperature range above Tg, a second peak of the loss factor appears by virtue of consumption of vibration energy caused by friction at the interface between air bubbles and polymer attendant to expansion and contraction. That is, peaks of the loss factor appear at two temperatures, and the temperature dependency is decreased.

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Nara, Japan

Seiji Sakurada