| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a direct injection internal combustion engine wherein fuel is injected in the latter-half of a compression stroke, and diffusion is stimulated in the root of fuel sprays without utilizing a collision with the wall surface. <P>SOLUTION: In a plan view, a plurality of protrusions 31a are radially formed at the same angular intervals on the tapered face of a land 31 formed on the bottom of a cavity C on the top of a piston 30. The protrusions 31a are arranged respectively along axes X of fuel sprays corresponding to the directions of the respective extensions. Thus, respective fuel sprays travel in the space (protrusion space) between the corresponding protrusions 31a and a cylinder head 20 in the direction of extension of the corresponding protrusions 31a. When fuel is injected in the latter half of the compression stroke, pressure in the protrusion space becomes higher than the pressure in the other parts, caused by the fact that the ratio of the volume of the protrusion space to the volume of the other-part space is diminished by the development of compression by the piston. The pressure difference causes spreading of respective fuel sprays in the circumferential direction. <P>COPYRIGHT: (C)2009,JPO&INPIT</p> |
