Intake sound control apparatus
AssigneeNippondenso Co., Ltd.
InventorsKatsuyuki Tanaka, Masanori Kato, Kouzi Ohara, Tokio Kohama, Yoshitaka Nishio
Life of this patent
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Abstract
A device for cancelling annoying sounds caused by operation of an internal combustion engine. An intake sound of the engine, and also a rotational speed of the engine, are obtained. The phase difference between the present intake sound and a desired intake sound is obtained using map data. The map data depends on the rotational speed of the engine and is specifically calculated so that at least the (n+0.5) harmonics (n integer.gtoreq.0) are cancelled. The phase data is used to drive a ceramic speaker or two oppositely directed ceramic speakers, to appropriately compensate the input sound.
Claims19
An intake sound control apparatus for an internal combustion engine which has an intake passage, comprising:
- detecting means for detecting an intake sound and a rotational speed of said internal combustion engine;
- a resonator, provided in said intake passage, for resonating frequency components of said intake sound;
- control means for producing a sound signal on the basis of a detected intake sound by said detecting means, said sound signal having characteristics for cancelling at least a sound having plural harmonics having frequencies (n+0.5) times a detected rotating speed by said detecting means, where n is an integer and n.gtoreq.0;
- cancelling sound generating means provided in said resonator, acoustically coupled to said intake passage for generating a cancelling sound on the basis of said sound signal.
An intake sound control apparatus for an internal combustion engine which has an intake passage, comprising:
- a sensor which detects an intake sound of said internal combustion engine;
- means for determining a rotational speed of said internal combustion engine;
- sound cancelling means, receiving said intake sound and said rotational speed, for processing said intake sound based on said rotational speed to produce a sound signal having characteristics for changing sound pressure levels of at least first frequency components of said intake sound, said sound signal produced from said intake sound;
- a resonator, provided in said intake passage, for resonating second frequency components of said intake sound, said second frequency components being different from said first frequency components;
- and
- acoustic wave generating means provided in said resonator, acoustically coupled to said intake passage, for generating an acoustic wave corresponding to said sound signal;
- wherein said resonator includes a wall defining first and second hollow portions on opposite sides thereof, said second frequency components being resonated by said first hollow portion and said acoustic wave generating means being provided in said second hollow portion.
An intake sound control apparatus for an internal combustion engine which has an intake passage, comprising:
- a resonator, provided in said intake passage of an internal combustion engine, for resonating in accordance with first frequency components of an intake sound;
- a sensor which detects an intake sound of said internal combustion engine;
- sound cancelling means, receiving said intake sound, for altering characteristics of said intake sound to produce a sound signal having characteristics for changing sound pressure levels of at least said first frequency components of said intake sound, said sound signal being produced from said intake sound;
- and
- acoustic wave generating means provided in said resonator, acoustically coupled to said intake passage and receiving said sound signal as an input thereof, for generating an acoustic wave corresponding to said sound signal;
- wherein said resonator includes a wall defining first and second hollow portions on opposite sides thereof, second frequency components different from said first frequency components, being resonated by said first hollow portion and said acoustic wave generating means being provided in said second hollow portion.
Dependencies are inferred from the claim text.