Engine exhaust noise suppressor
AssigneeNissan Motor Co., Ltd.
InventorsKazushige Maeda, Akira Sasaki
Life of this patent
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Abstract
The inner area of a muffler of an engine is partitioned into an expansion chamber, a first volume chamber and a second volume chamber. An inlet tube and the first volume chamber are connected by a first passage. The first volume chamber and a second volume chamber are connected by a second passage, and the second volume chamber and expansion chamber are connected by a third passage. The flow of exhaust gas reaching the expansion chamber via the first passage, second passage and third passage is blocked by a valve which opens according to a pressure rise of the exhaust gas. One of the two acoustic paths formed when the valve is open functions as a resonator having two degrees of freedom relative to the other path so that a high muffling effect is obtained.
Claims20
An exhaust noise suppressor for use with an engine, comprising:
- a muffler whereof the inner area is partitioned into an expansion chamber, a first volume chamber and a second volume chamber,
- an inlet tube for leading engine exhaust gas into said expansion chamber, said inlet tube having an orifice of a first area, said orifice being directly connected to said expansion chamber,
- a tail tube for discharging exhaust gas of said expansion chamber outside said muffler,
- a first passage connecting said inlet tube and said first volume chamber, said first passage having an opening of a second area greater than said first area,
- a second passage connecting said first volume chamber and said second volume chamber,
- a third passage connecting said second volume chamber and said expansion chamber,
- a valve for blocking a flow of exhaust gas travelling from said inlet tube to said expansion chamber via said first passage, said second passage and said third passage, said valve actuating in response to creation of a threshold pressure differential between the flow travelling through said first area and the flow travelling through said second area.
Dependencies are inferred from the claim text.