| 摘要 |
PURPOSE:To permit a desired swirl to be generated in a suction port of a cylinder head, by making a radius of curvature at a downstream end of a suction pipe in a horizontal direct-injection type internal-combustion engine. CONSTITUTION:A body part 10a of a suction pipe 10 is so arranged as to leave a side surface of a cylinder head 3 as it approaches a suction opening 4. A downstream end 10b of the body part 10a on the suction opening 4 side is gently largely bent, and is fixedly connected to the suction opening 4. A radius of curvature R3 of an inner circumferential side wall in a radial direction of the downstream end 10b as gently curved is largely set, and a length of the circular arc is elongated to be connected to the suction opening 4 with a large arcuate surface formed. As air in a suction port 7 is swirled in such a manner as to surround a valve guide 8, a swirl ratio is improved and a combustion efficiency is increased. |
