Offset passive valve for vehicle exhaust system

Abstract

An exhaust component includes a wall with an inner surface defining an exhaust gas flow path. A passive valve assembly includes a vane that is positioned within the exhaust gas flow path to be pivotable between open and closed positions. The vane is defined by a plane that extends across a width of the vane. The vane is supported by a shaft that defines an axis of rotation. The axis of rotation is offset from the plane of the vane such that the vane can be pivoted to a fully open position without interfering with the inner surface of the wall.

Description

RELATED APPLICATIONS[0001]This application claims priority to provisional application No. 60 / 989,508 filed on Nov. 21, 2007.TECHNICAL FIELD[0002]The subject invention relates to an offset passive valve in a vehicle exhaust system.BACKGROUND OF THE INVENTION[0003]Exhaust systems are widely known and used with combustion engines. Typically, an exhaust system includes exhaust tubes that convey hot exhaust gases from the engine to other exhaust system components, such as mufflers, resonators, etc. Mufflers and resonators include acoustic chambers that cancel out sound waves carried by the exhaust gases. Although effective, these components are often relatively large in size and provide limited nose attenuation.[0004]Passive valves have been used in a muffler to provide further noise attenuation. However, the proposed valves have numerous drawbacks that limit their widespread use in a variety of applications. One disadvantage with passive valves is their limited use in high temperature c...

AI Technical Summary

Problems solved by technology

Although effective, these components are often relatively large in size and provide limited nose attenuation.

However, the proposed valves have numerous drawbacks that limit their widespread use in a variety of applications.

One disadvantage with passive valves is their limited use in high temperature conditions.

Another disadvantage with known passive valve configurations is that these valves do not effectively attenuate low frequency noise.

Increasing muffler volume is disadvantageous from a cost, material, and packaging space perspective.

Increasing backpressure can adversely affect engine power.

When the passive valve is used within an exhaust pipe, such as a pipe in a muffler or when used in a by-pass pipe configuration, challenges are presented when the passive valve is moved toward a fully open position.

When the vane is moved toward the fully open position potential interference challenges are presented by the shape of the pipe itself.

Limiting the opening angle is disadvantageous from a back pressure standpoint, in addition to failing to achieve a true fully open position for maximum flow.

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