초록 ▼

An acoustic board with an improved composite structure ( 1 ), suitable for reducing the sound of aircraft engines, wherein an upper layer consists of a fabric ( 7 ) having a high sensitivity to sound velocity and a supporting sheet ( 4 ) having a certain porosity; the upper layer is combined, in tur

An acoustic board with an improved composite structure ( 1 ), suitable for reducing the sound of aircraft engines, wherein an upper layer consists of a fabric ( 7 ) having a high sensitivity to sound velocity and a supporting sheet ( 4 ) having a certain porosity; the upper layer is combined, in turn, with an intermediate honeycomb layer ( 2 ) and with a lower layer ( 5 ) of the conventional type.

대표청구항 ▼

1. An acoustic board having an improved composite structure ( 1 ), suitable for reducing the sound of aircraft engines, which consists essentially of an outer upper layer, consisting of a fabric ( 7 ), made of a material selected from the group consisting of metallic fibers, graphite and nylon havin

1. An acoustic board having an improved composite structure ( 1 ), suitable for reducing the sound of aircraft engines, which consists essentially of an outer upper layer, consisting of a fabric ( 7 ), made of a material selected from the group consisting of metallic fibers, graphite and nylon having nominal resistance and a high sensitivity to sound particle velocity, said outer upper layer being disposed over a lower perforated supporting sheet ( 4 ) having higher porosity than said outer upper layer, said lower perforated supporting sheet ( 4 ) having an upper surface and a lower surface, said supporting sheet ( 4 ) being attached at its upper surface to said fabric ( 7 ) and at its lower surface to an intermediate honeycomb layer said intermediate honeycomb layer being closed by a lower layer ( 5 ) for the structure ( 1 ). 2. The acoustic board according to claim 1, wherein that said supporting sheet ( 4 ) comprises a series of apertures ( 6 ) which produce a percentage of open area. 3. The acoustic board according to claim 1, wherein the honeycomb intermediate layers ( 2 ) are made of a material selected from the group consisting of phenolic resin, plastic material, paper, and aramid. 4. The acoustic board according to claim 1, wherein the layer of fabric is attached, by means of an adhesive layer, to the upper surface of said supporting sheet ( 4 ) and said lower layer ( 5 ) is attached to said intermediate honeycomb layer ( 2 ).