US 5,962,821 A · Internal combustion engine noise reduction apparatus

Abstract

The present invention is a noise reduction apparatus for use in the exhaust system of an internal combustion engine which absorbs acoustical energy from the pressurized exhaust gases while minimizing restrictions on the exhaust gases as they flow therethrough. The relatively unrestricted exhaust gas flow provided by the present invention significantly reduces the build up of back pressure and the associated drop in power and performance of the engine. At the same time, by absorbing acoustical energy from the exhaust gases, the noise level of the exhaust system is reduced. The present noise reduction apparatus includes a housing operatively adapted for being disposed in the exhaust system of an internal combustion engine, and a plurality of sound absorbing layers disposed inside the housing. Each layer is operatively adapted to allow exhaust gases to flow therethrough while absorbing acoustical energy from exhaust gases coming in contact with the layer.

Claims20

Dependent claims

An apparatus comprising:

an internal combustion engine;
an exhaust system through which exhaust gases from said engine exit to atmosphere;
and
a noise reduction apparatus for reducing the sound level of exhaust gases exiting said exhaust system, said noise reduction apparatus comprising:
a housing mounted within said exhaust system so that exhaust gases can pass through said apparatus, said housing having an upstream end through which exhaust gases enter said apparatus and a downstream end through which exhaust gases exit said apparatus, and
a plurality of tubular sound absorbing layers mounted within said housing so as to be radially spaced apart relative to one another, each of said plurality of sound absorbing layers having an upstream end, being sufficiently porous to allow exhaust gases to flow therethrough and being operatively adapted to absorb acoustical energy from exhaust gases coming in contact therewith,
wherein said noise reduction apparatus is operatively adapted to allow at least some exhaust gases to flow therethrough relatively unrestricted, from one end of said noise reduction apparatus to the other, such as by not having to flow through a porous wall.

4 more elements

An internal combustion engine exhaust system through which exhaust gases from an engine exit to atmosphere, said exhaust system comprising:

a noise reduction apparatus for reducing the sound level of exhaust gases exiting said exhaust system, said noise reduction apparatus comprising:
a housing mounted within said exhaust system so that exhaust gases can pass through said apparatus, said housing having an upstream end through which exhaust gases enter said apparatus and a downstream end through which exhaust gases exit said apparatus, and
a plurality of tubular sound absorbing layers mounted within said housing so as to be radially spaced apart relative to one another, each of said plurality of sound absorbing layers having an upstream end, being sufficiently porous to allow exhaust gases to flow therethrough and being operatively adapted to absorb acoustical energy from exhaust gases coming in contact therewith,
wherein said noise reduction apparatus is operatively adapted to allow at least some exhaust gases to flow therethrough relatively unrestricted, from one end of said noise reduction apparatus to the other, such as by not having to flow through a porous wall.

1 more element

Dependencies are inferred from the claim text.

Internal combustion engine noise reduction apparatus

Life of this patent

Internal combustion engine noise reduction apparatus

Life of this patent

Abstract

Claims20