Engine cylinder head with precombustion chambers using ceramics insert
AssigneeNgk Spark Plug Co., Ltd.
InventorsTooru Matsuura, Yoshinori Narita
Life of this patent
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Abstract
The invention relates to a cylinder head for an internal combustion engine in which each combustion chamber has a prechamber. A cast metal body of the cylinder head has recesses each of which provides a prechamber, and a hollow and, for example, bell-shaped member of an adequately porous ceramics is cast-inserted in the inner surface defining each recess. Use is made of a ceramics low in thermal expansion coefficient and heat conductivity, such as aluminum titanate or cordierite, and the porosity of the ceramics is limited within the range of from 5 to 20%. The cast-inserted ceramics member can easily be machine-finished and, without any extra treatment, has sufficient strength and durability.
Claims6
A cylinder head for an internal combustion engine, comprising:
- a cast metal body having at least one recess which provides a precombustion chamber;
- and
- a hollow member which is made of a porous ceramics and cast-inserted in the inner wall surface of said cast metal body defining said recess and then machine finished such that the inner surface of the hollow member defines a major portion of the precombustion chamber, the porosity of said ceramics being in the range of from 5 to 20%.
A method comprising:
- forming a cast metal internal combustion engine cylinder head body having at least one recess which provides a precombustion chamber;
- cast-inserting a hollow member which is made of a porous ceramic having a porosity in the range of 5 to 20% in the inner surface of the cast metal body defining said recess such that the inner surface of the hollow member defines a major portion of the precombustion chamber;
- and
- machine finishing the hollow member.
Dependencies are inferred from the claim text.