| 摘要 |
PROBLEM TO BE SOLVED: To suppress the overlap of flames derived from injection holes from an initial stage of combustion, in a compression ignition type internal combustion engine having a piston which has a top face at which a heat insulation film is formed, and an in-cylinder injector which radially injects fuel toward the top face from the plurality of injection holes.SOLUTION: A top face of a piston 14 is divided into eight regions to which injected fuel is spread. The adjacent two regions of the eight regions are partitioned by a line which passes through an intermediate part of axial lines of the adjacent two injection holes. A heat insulation film 24a is formed at one of the adjacent two regions, and a heat insulation film 24b is formed at the other. The surface roughness Ra of the heat insulation film 24a 2 μm or less, and the surface roughness Ra of the heat insulation film 24b is 4 μm or more.SELECTED DRAWING: Figure 2 |
