Heat-insulating layer to prevent temperature drop of combustion gas in internal combustion engine
AssigneeNissan Motor Co., Ltd.
InventorShinichi Nagumo
Life of this patent
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Abstract
A heat-insulating layer secured to a cast metal member of an internal combustion engine so as to be exposed to combustion gas in the engine. A porous or intersticed metal body, preferably having a soft structure, is used as a fundamental material of this layer. A surface portion of the porous metal body is impregnated with a ceramic material, and then the metal body is cast-inserted into the metal member such that the molten metal infiltrates into another surface portion of the porous metal body and that the ceramic-impregnated portion is exposed to combustion gas in the engine. This heat-insulating layer is excellent in toughness, durability and bonding strength and can be embodied in a combustion chamber wall, exhaust port wall or a top portion of a piston.
Claims13
A heat-insulating layer secured to a cast metal member of an internal combustion engine in such an arrangement that the heat-insulating layer is exposed to a combustion gas produced in the engine, the heat-insulating layer comprising:
- a metal body having a porous structure, only a first surface portion of said metal body being impregnated with a heat-insulating ceramic material which is fired in said surface portion, a second surface portion of said metal body being cast-inserted into said cast metal member such that the metal of said cast metal member infiltrates into at least a part of said second surface portion and that said first surface portion is exposed to said combustion gas in the engine.
Dependencies are inferred from the claim text.