Suction apparatus for an internal combustion engine

摘要

A hollow-cylindrical heat conduction portion (44) is formed on a throttle body (42) in such a way as to protrude outwardly therefrom in the radial direction. The throttle body (42) and the heat conduction portion (44) are integrally formed using metal material such as aluminum having excellent heat conductivity or resin material containing such a metal material. A vent hole (31) communicating the interior with the exterior of a head cover (3) is formed in the head cover (3). Through the vent hole (31) there is inserted the heat conduction portion (44), and the clearance between an outer-peripheral wall thereof and an inner wall of the vent hole (31) is sealed by means of a seal member. <IMAGE>