Heat insulating device for engine

Abstract

Abstract PURPOSE:To prevent a heat insulating material from peeling off, by making up the heat insulating material consisting of ceramics into a three-layer construction, while installing an intermediate layer having innumerable pores, in position between both parts, one contacting the high temperature side and the other the low temperature side, when a high temperature part in an engine is partially insulated from heat. CONSTITUTION:A heat insulating material 11 is bonded to the top of a piston 4, the inner surface of a combustion chamber, the inner surface at the upper part side of a cylinder liner 2, the underside of a cylinder head 5 and the inner surface of an exhaust port 7, respectively. The heat insulating material 11 is composed of a second layer 13 forming a first layer 12 at the high temperature side and an intermediate layer and a third layer 14 at the low temperature side, and the layer 12 is made up of a ceramic material being small in a coefficient of thermal expansion such as alumina-silicon nitride or the like, while the layer 14 is made up of another ceramic material being large in the coefficient of thermal expansion such as zirconia or the like. Likewise, the layer 13 is made up of a metallic fiber aggregate having innumerable pores or a ceramic fiber aggregate, so that thermal stress attending on a difference in the coefficient of thermal expansion between both layers 12 and 14 is well buffered.

Inventors

• 👤 Toshio Kiyota
• 👤 清田　利夫

Bibliographic Details