US 7,524,224 B2
Internal combustion engine and outboard motor provided with the same
Shinichi Ide, Wako (Japan); Koji Kasai, Wako (Japan); Tetsu Wada, Wako (Japan); Tetsuro Ikeno, Wako (Japan); Shoji Hasei, Wako (Japan); and Hiroshi Takahashi, Wako (Japan)
Assigned to Honda Motor Co., Ltd., Tokyo (Japan)
Filed on Sep. 26, 2007, as Appl. No. 11/904,159.
Claims priority of application No. 2006-270087 (JP), filed on Sep. 29, 2006.
Prior Publication US 2008/0081523 A1, Apr. 03, 2008
Int. Cl. B63B 35/73 (2006.01)
U.S. Cl. 440—88A 13 Claims
OG exemplary drawing
 
1. An internal combustion engine installed in an engine compartment covered with an engine cover and comprising an intake system forming an intake air passage for carrying combustion air into a combustion chamber; wherein:
the intake air passage extends continuously in the engine compartment between an intake air inlet and intake air outlets;
the intake air passage has a first down passage for guiding the combustion air taken in through the intake air inlet to flow down, a reversing passage for reversing the flowing direction of the combustion air so as to flow up, an up passage for guiding the combustion air to flow up, and a second down passage for guiding the combustion air to flow down, the first down passage, the reversing passage, the up passage and the second down passage being successively arranged in that order from an upstream position toward a downstream position; and
the first down passage and the up passage extend between a position at a level higher than that of an uppermost one of the intake air outlets and a position below at least one of the air intake outlets.