The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 14, 1998
Filed:
Feb. 10, 1997
Nissan Motor Co., Ltd., Yokohama, JP;
Abstract
A first and second noise suppressing mechanism are provided inside the muffler. Each mechanism is provided with a discharge pipe for discharging exhaust gas to outside the muffler. The first noise suppressing mechanism reduces exhaust noise in the low engine speed region. The second noise suppressing mechanism reduces noise in the medium and high engine speed regions. A valve is provided that connects the first noise suppressing mechanism and second noise suppressing mechanism according to the engine exhaust pressure. In the low speed region, the valve is closed and exhaust gas is discharged via the first noise suppressing mechanism where mainly low frequency noise is eliminated. In the medium and high speed regions, the valve is opened and exhaust gas is also discharged via the second noise suppressing mechanism where high frequency noise specific in these regions is also eliminated. Further, by the increased exhaust cross-sectional area, power drop due to increase of back pressure in the muffler in the high speed region, is prevented.