Nissan Motor Company Limited

Yuji Ushijima

Yasuo Takagi

Kenji Yoneda

Fumio Sanezawa

A reed type valve is operatively secured on the outer surface of the casing of an engine air filter assembly to supply the exhaust system of an engine with secondary air. The reed valve is fluidly connected to an air induction passage formed inside the casing of the air filter assembly. A resonance chamber is also formed inside of the casing and communicates through a communication passage with the air induction passage so as to attenuate a relatively low frequency component of exhaust noise transmitted through the reed valve. The air induction passage, resonance chamber and communication passage are formed as follows: ##EQU1## where, S.sub.o (cm.sup.2)=the cross-sectional area of the air induction passage

Secondary air supply system

A reed type valve is operatively secured on the outer surface of the casing of an engine air filter assembly to supply the exhaust system of an engine with secondary air. The reed valve is fluidly connected to an air induction passage formed interior of the casing of the air filter assembly. A resonance chamber is also formed interior of the casing and communicated through a communication passage with the air induction passage so as to attenuate a relatively low frequency component of exhaust noise transmitted through the reed valve. The air induction passage, resonance chamber and communication passage are formed as follows: ##EQU1## where, S.sub.o (cm.sup.2)=the cross-sectional area of the air induction passage

Growing community of inventors

Yokohama, Japan

Yuji Ushijima