| 摘要 |
<p>PURPOSE:To promote mixing of the fuel and the air, by a method wherein the opening time of a suction valve located on the inner side of a suction port is set to earlier timing. CONSTITUTION:Through rotation of a cam shaft 22, a suction valve 12 is opened through a valve lifter 21 by a direct-acting cam 24, while a suction valve 13 through a locker arm 23 by a locker arm-operated cam 25, against the elastic force of springs 26 and 27 respectively. An opening time is staggered by alpha deg. in a crank angle, so that a suction valve 12 located on the inner side of a suction port 16 is opened earlier than a suction valve 13 situated on the side in the proximity of the end surface of the suction port. At the primary stage of suction, the velocity of flow-in of the sucked air is increased by a throttling effect, and an intense revolving air stream is generated in a peripheral direction along the inner wall of a cylinder. Thereafter, when the suction valve 13 is opened, the sucked air, carried on the air stream already produced, flows in the cylinder with a rush to produce a further intense main stream, and simultaneously, fine turbulent flows are created to promote mixing of the sucked air with the fuel jetted through a jet nozzle 19.</p> |
