| 摘要 |
PROBLEM TO BE SOLVED: To provide a heat insulation layer that has high heat insulation performance, can prevent fuel penetration, can maintain high heat insulation performance for a long term, and can improve heat efficiency of an engine.SOLUTION: A heat insulation layer 21 provided on the surface of a member 19 facing an engine combustion chamber contains hollow particles 23 mainly composed of an inorganic oxide, and a non-powder type dense binder material 25 connecting between the hollow particles 23 and between the hollow particle 23 and the member 19. The hollow particles 23 are contained in the heat insulation layer 21 at a volume ratio of 60 vol.% or more and 75 vol.% or less. The heat conductivity of the heat insulation layer 21 is in the range of 0.10 W/m K or more and 0.16 W/m K or less. The volume specific heat of the heat insulation layer 21 is in the range of 350 kJ/mK or more and 720 kJ/mK or less. |
