Engine noise control apparatus
US5692052A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | May 2, 1994 |
| Grant date | Nov 25, 1997 |
| Priority date | — |
| Expiry date | May 2, 2014 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG10K2210/3033
- WIPO fieldOther consumer goods
- WIPO sectorOther fields
Abstract
An engine rotating speed sensor detects intake sound information due to the drive of an engine. A controller generates a signal having a frequency corresponding to a desired ratio of orders based on the detected intake sound information. Further, a phase and an amplitude the signal are controlled, and so a speaker arranged in a propagation path of the intake sound of the engine generates control sound to control the intake sound due to the drive of the engine. An engine noise control apparatus which is capable of effectively reducing or waveform-reshaping a wide range of engine noise. The apparatus has an engine rotating speed sensor for detecting an engine rotating speed and a waveform generator circuit for converting a rotation pulse signal to a periodic signal having a frequency which is a predetermined multiple of the detected engine rotating speed. The output of an air flow meter is passed through a bandpass filter and a reshaping circuit to generate a control signal which is an average value of alternating current components of the output. A CPU, with reference to a map previously stored in a memory, modifies the phase and amplitude of the periodic signal with respect to an e…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.