Patent ID: 7117974

Claim:
An in-line resonator for an air induction system of an internal combustion engine comprising: a resonator housing defining a compartment having a fixed volume and having an axis; an upstream duct connected to the housing and extending therefrom; a downstream duct connected to the housing opposite the upstream duct and extending therefrom; a conduit connected with the upstream duct and extending through the housing, said conduit having a conduit end located within the downstream duct; a partition located within the housing and dividing the compartment into an upstream chamber adjacent to the upstream duct and a downstream chamber adjacent to the downstream duct, said partition being axially moveable thereby changing volumes of said upstream chamber and said downstream chamber; a sleeve including upstream and downstream portions positioned about said conduit axially, said downstream portion of the sleeve including inner and outer portions, radially spaced apart from each other, that cooperate with the conduit to define a connector passage connecting the downstream duct and the downstream chamber, said connector passage having a length defined between a downstream end of said conduit and an upstream end of the outer downstream sleeve, and said connector having a cross-sectional area defined by the annular gap between the inner downstream sleeve and outer downstream sleeve; said downstream chamber, said conduit, and said inner and outer downstream sleeves cooperating to define a downstream Helmholtz resonator in fluid communication with said downstream duct through said connector passage, and further wherein said Helmholtz resonator is characterized by the volume of said downstream chamber, the cross-sectional area of said passage, and the length of said connector passage; a sliding unit including said partition, said upstream sleeve, and said downstream sleeve; and an actuator coupled to said sliding unit and adapted to move the partition to vary the volume of said downstream chamber and concurrently to vary the length of said connector passage.