Sound dampened automotive enclosure such as an oil pan
AssigneeSoundwich, Inc.
InventorsDan T. Moore, III, Edward A. Collins, Maurice E. Wheeler
Life of this patent
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Abstract
The invention concerns constrained layer sound damping. A composition and a laminated structure are provided for the reduction of noise coming from housings such as oil pans for automobiles. The composition comprises a rubbery polyurethane, an olefin polymer, and a filler. The laminated structure comprises the housing, the composition, and a sheet metal liner. The composition contains a blowing agent which is activated to provide a single unitary structure which dampens noise. The polyurethane and olefin polymer are thoroughly intermixed with each other, but maintain their separate identities in the blend.
Claims6
An automotive component enclosure comprising:
- a stamped metal housing having internal surfaces which define an internal cavity;
- at least one thin metal liner which is attached to an internal surface of said metal housing and conforms to the surface to which it is attached;
- a constrained layer of foamed viscoelastic compound between each internal surface and liner, said compound comprising at least two polymers which form a heterogeneous mixture in the compound, containing from 15% to 35% by weight of filler which has a specific gravity of from about 2.4 to about 3.0 and being resistant to degradation after being soaked in lubricant at an elevated temperature;
- said constrained layer being adhered to the internal surface and the liner as the result of the activation of a blowing agent therein, said liner and constrained layer forming a unitary structure with said metal housing which suppresses the transmission of sound.
An oil pan for use with a vehicle, comprising:
- a stamped metal housing having internal surfaces which define a cavity for the retention of oil;
- at least one relatively thin metal liner which conforms to one of the internal surfaces of the housing and is attached thereto by spot welding;
- a constrained layer of foamed viscoelastic compound between each liner and the housing which comprises from about 45% to about 65% by weight of at least one polyester urethane polymer, from about 10% to about 30% by weight of a high molecular weight oil-insoluble olefin polymer, and from about 15% to about 35% by weight of at least one filler, said polymers being thoroughly intermixed with each other but substantially retaining their separate identities in the compound;
- said viscoelastic compound having contained a blowing agent which was activated by heat so as to expand it enough to cause it to adhere to the surfaces of the housing and the liners and form a unitary structure therewith.
Dependencies are inferred from the claim text.