Patent Application
20080168961
The present invention relates to an intake assembly incorporating a supercharger having integral resonators formed on an inlet side of a supercharger housing.
Various methods may be employed to reduce the intake noise of an internal combustion engine. One method is to use a Helmholtz resonator on an intake air pipe configured to communicate intake air to the internal combustion engine. The intake air pipe is typically disposed upstream from an intake manifold and is configured to communicate intake air to the intake manifold of the internal combustion engine. A Helmholtz resonator includes a resonance volume or chamber having a small opening, typically referred to as a neck. The neck is operable to enable communication between the resonance chamber and the intake air pipe. Sound waves generated by components within the internal combustion engine travel along the intake air pipe where their acoustic pressure impinges on the neck. This acoustic pressure excites a mass of air within the neck. The acoustic pressure within the resonance chamber reacts against the air mass within the neck and produces an out-of-phase acoustic pressure at the intake air pipe to cause cancellation of intake noise at the resonant frequency. In this way, some of the engine noise is eliminated as the out-of-phase acoustic pressures in the intake air pipe cancel each other.
The frequency at which the attenuating acoustic pressures reach their maximum amplitude is known as the resonant frequency. A number of parameters determine the resonant frequency and bandwidth of a Helmholtz resonator, including the volume of the resonance chamber and the length and cross sectional area of the neck.
An intake assembly, such as a supercharger assembly, is provided for an internal combustion engine. The intake assembly includes a housing having a wall defining an inlet passage through which intake air enters the intake assembly. A plurality of stiffening ribs are provided on the wall opposite the inlet passage and at least partially define at least one cavity. A plate is mounted to the wall of the housing and further defines the at least one cavity. The wall defines at least one orifice configured to provide communication between the inlet passage and the at least one cavity. The at least one cavity and the at least one orifice cooperate to form at least one resonator. Preferably, the plate is sealingly engaged with the wall of the housing, such as by a gasket member, sealant, etc.
A method of forming integral resonators within the intake assembly is also provided including the steps of. A) forming the orifices in the housing operable to provide communication between the inlet passage and the cavities; and B) mounting the plate to the housing to further define the cavities. As mentioned hereinabove, the orifices and the cavities cooperate to form the resonator. The method further includes the step of sealing the plate with respect to the housing.
The above features and advantages and other features and advantages of the present invention are readily apparent from the following detailed description of the best modes for carrying out the invention when taken in connection with the accompanying drawings.
Referring to the drawings wherein like reference numbers correspond to like or similar components throughout the several figures, there is shown in
A plurality of stiffening ribs 28 are provided on the housing 12 to prevent distortion of the housing 12 during operation of the supercharger assembly 10. The stiffening ribs 28 are preferably arranged in a generally cross-wise arrangement to form a waffle pattern. Referring now to
As illustrated in
By positioning the resonators 38 near the noise source, i.e. the supercharger assembly 10, the pressure pulses acting on the housing 12 may be reduced resulting in less radiation of noise than with noise attenuation devices mounted further upstream of the inlet passage 16 of the supercharger assembly 10. Additionally, the flow of intake air 18 through the intake passage 16 may improve by employing the resonators 38 as a result of the cancellation of pressure pulses within the inlet passage 16 of the supercharger assembly 10.
A method of forming integral resonators 38 within the supercharger assembly 10 is also provided including the steps of: A) forming the orifices 32 in the housing 12 operable to provide communication between the inlet passage 16 and the cavities 30; and B) mounting the plate 34 to the housing 12 to further define the cavities. As mentioned hereinabove the orifices 32 and the cavities 30 cooperate to form the resonator 38. The method further includes the step of sealing the plate 34 with respect to the housing 12. The orifices 32 may be formed by machining the housing 12 such as by drilling or reaming. Alternately, if the housing 12 is a cast component, the orifices 32 may be formed by pin-like mold features, not shown, disposed within a mold, not shown, and used to form the housing 12. The pin-like mold features may form closed ended bores, such that the orifices 32 are formed by the removal of material from the resulting closed ended bores during the machining of the inlet passage 16.
While the best modes for carrying out the invention have been described in detail, those familiar with the art to which this invention relates will recognize various alternative designs and embodiments for practicing the invention within the scope of the appended claims.
