| 摘要 |
PROBLEM TO BE SOLVED: To provide a cylinder head structure which can suppress the lowering of ignitability at a cold start of a compression ignition type engine, and the lowering of warmup performance.SOLUTION: A heat insulation film 24 is formed in a fan-shaped region having a center angle θ surrounding an attachment hole 22a of a glow plug 22. The fan-shaped region is set responding to a region in which injected fuel from a specified injection hole is spread, and the center angle θ is set not larger than an angle which is obtained by dividing 360° by the number of all the injection holes, that is, 90°. A heat insulation film 26 is formed in the other region which surrounds the fan-shaped region, that is, a fan-shaped region of a center angle (360°-θ). The surface roughness Ra of the heat insulation film 24 is 6 to 8 μm in average. The surface roughness Ra of the heat insulation film 26 is 1 to 2 μm in average.SELECTED DRAWING: Figure 2 |
