Resonator Neck Insert
Publication Date: 2015-Jan-28
The IP.com Prior Art Database
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Resonator Neck Insert
Known State of the Art
Resonators such as Helmholtz resonators may be applied to a vehicle air intake tract to reduce engine noise by attenuating undesired sound frequency ranges. Resonator necks for connecting the resonator to the air intake tract are traditionally molded into or with the resonator as a one piece component.
Typically, it is known that the resonant frequency of a quarter wave resonator is tuned by varying the length of a pipe. The resonant frequency of a Helmholtz resonator may be varied by varying the volume of the resonant chamber. In this way the resonant frequency may be fixed to enable attenuation of unwanted frequencies of acoustic vibrations in an air intake tract.
Description of the Invention
When air is forced into a resonator cavity, the pressure inside increases. Once the external force that forces the air into the cavity disappears, the higher-pressure air inside will flow out. However, this surge of air flowing out will tend to over-compensate, due to the inertia of the air in the neck, and the cavity will be left at a pressure slightly lower than the outside, causing air to be drawn back in. This process repeats with the magnitude of the pressure changes decreasing each time.
In simple terms, a larger diameter neck opening provides a high resonant frequency as the air can rush in and out of the resonator faster (in less time). Likewise (in simple terms), a larger resonator volume provides a lower resonant frequency since more air must move in and out of the resonator cavity to relieve a given pressure excess or differential.
As one can readily appreciate, it is very advantageous to be able to tune these parameters for a given resonator simply by varying the neck insert diameter and length without having to change or redesign the resonator.
The present inventive concept provides a resonator, advantageously however, this resonator has an injection molded resonator neck that is a separate component from the resonator. By this means, the inventive resonator may accommodate any of a variety of stocked or custom made resonator neck inserts, each having a different neck length and/or neck diameter configured to adaptor tune the resonator a desired sound spectrum to be attenuated.
The present inventive resonator, therefore, has the neck a separate component. This configuration allows the user to change the frequency of the resonator by changing the nec...