Noise isolation sheet

Abstract

There is provided a noise isolation sheet 10 which is comprised of an optional number of closed-cell foamed layer 11, open-cell foamed layer 12 and fibered noise absorbing material 13, being laminated in an optional order, and which insulates the noise near 1000 Hz. Further, there is provided a noise isolation sheet 10 comprised of an optional number of the closed-cell foamed layer 11 and the fibered noise absorbing material 13 being laminated in an optional order. There is also provided a noise isolation sheet 10 comprised of an optional number of the open-cell foamed layer 12 and the fibered noise absorbing material 13 being laminated in an optional order. Each noise isolation sheet 10 is used to partially or fully cover an interior side of a door inner panel of a vehicle.

Description

BACKGROUND OF THE INVENTION [0001] This invention relates to a noise isolation sheet which is used, for example, as a sheet installed to an interior side of an automobile door. [0002] There have conventionally been applied various noise isolation means to an inner side of an automobile door with an aim of preventing external noise from invading into an interior of the automobile as well as preventing internal noise from leaking to an outside. For example, there have been invented such means that a felt or urethane is attached to a backside of an interior door trim which is installed to an interior side of a door inner panel, and that an urethane made product is attached to a door inner panel. [0003] Regarding to the prior art described above, the applicant of this invention has invented a noise isolation sheet and filed it (Japanese Patent Publication No. 2004-020415) in order to improve a noise isolation property of the conventional noise isolation means. As illustrated in FIG. 15,...

AI Technical Summary

Benefits of technology

[0025] According to the noise isolation sheet in the fourth aspect of the invention, the fibered noise absorbing material is laminated in addition to the closed-cell foamed layer and the open-cell foamed layer, so that it is highly effective in isolating the noise near 1000 Hz. Therefore, by covering with this noise isolation sheet an interior side of a door inner panel of a vehicle, an external noise is effectively prevented from invading into an interior of the vehicle, while an internal noise is prevented from leaking to the external of the vehicle.

[0026] According to the noise isolation sheet in the fifth aspect of the invention, the closed-cell foamed layer and the fibered noise absorbing material are laminated, so that it is highly effective in isolating the noise near 1000 Hz, and is improved in the noise isolating property of an interior of a vehicle. Further, a door of a vehicle is improved in the waterproof property by a performance of the closed-cell foamed layer.

[0027] According to the noise isolation sheet in the sixth aspect of the invention, the open-cell foamed layer and the fibered noise absorbing material are laminated, so that it is also highly effective in isolating the noise near 1000 Hz, and it can improve the noise isolation property of an interior of a vehicle. Further, it can demonstrate the higher noise isolation property by a great performance of the open-cell foamed layer in isolating the noise.

[0028] According to the noise isolation sheet in the seventh aspect of the invention, the layer positioned in the outermost exterior side of the vehicle in the fourth or fifth aspect of the invention is the closed-cell foamed layer, so that the door of the vehicle can be improved in the waterproof property by a performance of the closed-cell foamed layer which is highly effective in the waterproof property.

[0029] According to the noise isolation sheet in the eighth aspect of the invention, the layer positioned in the outermost external side of the vehicle in the sixth aspect of the invention is the open-cell foamed layer, so that the vehicle door is improved in the noise isolation property by a performance of the open-cell foamed layer which is greatly effective in isolating the noise.

[0030] According to the noise isolation sheet in the ninth aspect of the invention, the fibered noise absorbing material in any of the preceding invention is the urethane chip felt or the resin felt, so that it can demonstrate a highly effective noise isolation property, and that it is economical.

Problems solved by technology

Further, the noise absorbing material disclosed in the Unexamined Patent Publication No. 8-146967 is only effective in absorbing the noise in a range of 100 Hz to 300 Hz, and it is not satisfying in absorbing the noise near 1000 Hz.

The noise absorbing material disclosed in the Japanese Patent Publication No. 2503215 is not satisfying either in absorbing the noise near 1000 Hz.

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