HEAT-INSULATING MEMBER AND ENGINE COMBUSTION CHAMBER STRUCTURE

摘要

There are provided a heat-insulating member which enhances a thermal efficiency of an engine to enhance fuel efficiency, and a structure of a combustion chamber for the engine. A heat-insulating member 1 includes a substrate 5, an insulating porous layer 3, and a surface dense layer 2. The substrate 5, the insulating porous layer 3 and the surface dense layer 2 are formed of a ceramic material. The surface dense layer 2 has a porosity of 5% or less. Furthermore, the insulating porous layer 3 has a larger porosity than the surface dense layer 2. The substrate 5 sufficiently has a mechanical strength to exist in a self-supported manner. The heat-insulating member 1 is fixed to a piston 14 by mechanical fixing such as screwing or chemical fixing such as brazing.