Nichias Corporation

Toyota Jidosha Kabushiki Kaisha

Kunihiko Yano

Takahiro Niwa

Masaki Yoshihara

Katsunori Ueda

Atsushi Omura

Seiji Sakurada

Hiroshi Saito

Keiji Tsukahara

Takahiro Ohmura

Toshihiko Kumasaka

Tadashi Arai

Shyuichi Ishiwa

Sunao Ichihara

Vibration damping shim structure

A squeak preventing shim for a disk brake for an automobile has a squeak preventing effect, even if no lubricant is used, and also prevents decreased durability due to buckling, flow, etc. A shim construction is formed with a plurality of grooves or recesses in rubber layers,disposed on two surfaces of a metal plate in a rubber coated member. Owing to these grooves or recesses, apparent transversal elastic modulus of the rubber layers is lowered and a squeak preventing effect due to vibration in a parallel direction to the shim can be obtained, even if no lubricant is used. Further, since longitudinal elastic modulus does not vary much, the shim construction is durable.

Squeak preventing shim

A constraint type vibration damping material, which exhibits a high vibration damping performance and can realize easiness of processing and a low cost at the same time, is provided, in which a polymer viscoelastic layer made of rubber, etc. is formed on at least one surface of a rigid body such as a metal plate, etc. and a hard cover layer having a rigidity modulus greater than that of the viscoelastic layer and smaller than that of the rigid body. Since the hard cover layer having a great rigidity modulus acts as a constraining material, which forms as the result a pair with the rigid body. Further, since the polymer viscoelastic layer and the hard cover layer can be formed by continuous fabrication steps, it can be advantageous from the point of view of the cost.

Constraint type vibration damping material

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 construction, which is useful when it is applied to a vibration isolation washer or a pressed construction such as an oil pan, a ventilation buffle plate, etc. for an automobile, is disclosed, which is so constructed that raw materials, in each of which a rubber visco-elastic layer or such layers is or are disposed on one or two surfaces of a metal plate, are laminated on each other, so that rubber visco-elastic layers are opposite to each other, and adhered to each other to form a laminated body; rectangular pawls are formed on the raw material at the uppermost layer and the laminated body; rectangular cut-off windows, with which the cut and raised pawls can be engaged, are formed in the raw material at the lowermost layer; and these are laminated on each other and bound in one body by spot connection by means of the pawls.

Vibration damping body and method for fabricating same

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.

Vibration damping material

Growing community of inventors

Saitama, Japan

Kunihiko Yano