To suppress the sudden change in sound pressure of intake sound generated according to the opening and closing of a valve and to reduce the intake sound in high-speed rotation of an engine.
This intake device 1 has a first duct 3 having one end 3a opened to the atmosphere and the other end 3b communicating with an air cleaner 2; a second duct 6 having one end 6a opened to the atmosphere and the other end 6b communicating with the air cleaner 2; and the valve 5 arranged in the first duct 3, which is closed in the low-speed rotation of the engine to interrupt the inflow of intake air to the air cleaner 3 from the atmospherically opened end 3a of the first duct 3, and opened in the high-speed rotation of the engine to permit the inflow of intake air to the air cleaner 2 from the end 3a of the first duct 3. The first duct 3 has a hole part 7 located on the upstream side of the intake flow of the valve 5 and communicating with the inside and outside of the first duct 3.
Tsuyoshi Hashimoto
Hiromichi Kobayashi
Tomioka Kiyoshi