Intake duct and intake system for internal combustion engine

摘要

Fuel supply devices for an engine are disposed within an intake duct located upstream of an air cleaner. Thus, the fuel supply devices such as fuel injection valves and a fuel supply pipe are always cooled by intake air flow while the engine is being driven. In addition, heat conducted from the engine to the fuel supply device can be insulated by the intake duct when the engine is stopped. Further, since the intake duct located upstream of the air cleaner does not dispose functional parts such as a filter therein, a high degree of freedom for mounting the intake duct on the engine is maintained so that the intake duct can be easily disposed at the position where the fuel supply devices are located.