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US4648308A Expired / Lapsed US ⏱️ 0.0 years remaining

Internal combustion engine piston and a method of producing the same

Assignee: NGK Insulators Ltd
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Filing: 1985-03-05
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Granted: 1987-03-10
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Expires: 2005-03-05
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Abstract

Abstract Disclosed herein is an internal combustion engine piston comprising a piston cap formed from a plurality of ceramic pieces, and a metal piston body, the piston cap being fixed to the top portion of the metal piston body, wherein the piston cap is made of one or more types of ceramic materials, and the ceramic pieces constituting the ceramic cap and the metal piston body are bonded together through a metallized layer coated onto the ceramic pieces and a metal-plated layer coated onto the metallized layer in such a manner that the bonding area between the ceramic piece or pieces and the metal piston body may be larger at a top central portion of the metal piston body than that between the ceramic piece or pieces and the metal piston body at another portion thereof. Also disclosed is a method of producing the same.

Inventors

  • 👤 Minoru Matsui
  • 👤 Nobuo Tsuno

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-02 20:13
CPC Classifications
F; F02; F02F; F02F3/00; F02F3/10; F02F3/12; F02B; F02B23/00; F02B23/02; F02B23/06; F02B23/0603; F02B23/0696; F02B77/00; F02B77/11; F02F7/00; F02F7/0085; F02F7/0087; F02B2023/0612; F02B3/00; F02B3/06; F05; F05C; F05C2201/00; F05C2201/04; F05C2201/0433; F05C2201/0448; F05C2251/00; F05C2251/04; F05C2251/042; F05C2253/00; F05C2253/16; G; G02; G02B; G02B6/00; G02B6/24; G02B6/26; G02B6/35; G02B6/3564; G02B6/3568; G02B6/357; Y; Y02; Y02T; Y02T10/00; Y02T10/10; Y02T10/12; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49229; Y10T29/4927; Y10T29/49272

Claims Analysis

Total Claims: 13
Claim 1
Independent Claim 138 words
An internal combustion engine piston comprising a piston cap which includes a plurality of ceramic pieces, and a metal piston body, said metal piston body having a top portion, the piston cap being fixed to the top portion of the metal piston body, wherein the piston cap comprises at least one ceramic material, and said plurality of ceramic pieces comprising the ceramic cap are bonded to the metal piston body through a metallized layer coated upon said plurality of ceramic pieces and a metal-plated layer coated upon the metallized layer such that a bonding area created between said plurality of ceramic pieces and the metal piston body is greater at a central portion on top of the piston body than a bonding area between said plurality of ceramic pieces and the metal piston body at any other portion.
Claim 2
Dependent Claim 138 words
An internal combustion engine piston comprising a piston cap which includes a plurality of ceramic pieces, and a metal piston body, said metal piston body having a top portion, the piston cap being fixed to the top portion of the metal piston body, wherein the piston cap comprises at least one ceramic material, and said plurality of ceramic pieces comprising the ceramic cap are bonded to the metal piston body through a metallized layer coated upon said plurality of ceramic pieces and a metal-plated layer coated upon the metallized layer such that a bonding area created between said plurality of ceramic pieces and the metal piston body is greater at a central portion on top of the piston body than a bonding area between said plurality of ceramic pieces and the metal piston body at any other portion.
Claim 3
Dependent Claim 38 words
An internal combustion engine piston according to claim 1, wherein any ceramic piece bonded to the metal piston body determines a position on the metal piston body of any remaining ceramic pieces from said plurality of ceramic pieces.
Claim 4
Dependent Claim 34 words
An internal combustion engine piston according to claim 1, wherein at least one ceramic piece which is not bonded to the metal piston body is fixed to the metal piston body by interference fitting.
Claim 5
Dependent Claim 55 words
An internal combustion engine piston according to claim 1, wherein a buffer metallic member having a coefficient of thermal expansion less than or equal to a thermal expansion coefficient of the ceramic pieces coated with the metallized layer is provided between the metal plated layer coated onto the metallized layer and the metal piston body.
Claim 6
Dependent Claim 33 words
An internal combustion engine piston according to claim 1, wherein the ceramic pieces comprise at least one ceramic material selected from the group consisting of zirconia, alumina, silicon nitride, silicon carbide, and sialon.
Claim 7
Dependent Claim 26 words
An internal combustion engine piston according to claim 1, wherein each of said plurality of ceramic pieces comprising the ceramic cap have rounded outer peripheral portions.
Claim 8
Independent Claim 188 words
A method of producing an internal combustion engine piston by fixing a piston cap, which includes a plurality of ceramic pieces, to a top portion of a metal piston body, which comprises the steps of: forming the piston cap from at least one ceramic material, coating the surface of at least one ceramic piece of said plurality of ceramic pieces comprising the piston cap which is to be faced with and bonded to the metal piston body with metallized layer, coating the surface of the metallized layer with a metal plated layer, arranging said plurality of ceramic pieces in a depression formed in said top portion of the metal piston body, and bonding the piston cap and the metal piston body together through the metallized layer on the ceramic pieces and the metal plated layer coated on the metallized layer, such that a bonding area created between said plurality of ceramic pieces and the metal piston body is greater at a central portion on top of the piston body than a bonding area between said plurality of ceramic pieces and the metal piston body at any other portion.
Claim 9
Independent Claim 188 words
A method of producing an internal combustion engine piston by fixing a piston cap, which includes a plurality of ceramic pieces, to a top portion of a metal piston body, which comprises the steps of: forming the piston cap from at least one ceramic material, coating the surface of at least one ceramic piece of said plurality of ceramic pieces comprising the piston cap which is to be faced with and bonded to the metal piston body with metallized layer, coating the surface of the metallized layer with a metal plated layer, arranging said plurality of ceramic pieces in a depression formed in said top portion of the metal piston body, and bonding the piston cap and the metal piston body together through the metallized layer on the ceramic pieces and the metal plated layer coated on the metallized layer, such that a bonding area created between said plurality of ceramic pieces and the metal piston body is greater at a central portion on top of the piston body than a bonding area between said plurality of ceramic pieces and the metal piston body at any other portion.
Claim 10
Dependent Claim 42 words
A method of producing an internal combustion engine piston according to claim 7, wherein any ceramic piece bonded to the metal piston body, determines a position on the metal piston body of any remaining ceramic pieces from said plurality of ceramic pieces.
Claim 11
Dependent Claim 44 words
A method of producing an internal combustion engine piston according to claim 7, wherein at least one ceramic piece which is not bonded to the metal piston body among those comprising the piston cap is fixed to the metal piston body by interference fitting.
Claim 12
Dependent Claim 59 words
A method of producing an internal combustion engine piston according to claim 7, wherein a buffer metallic member having a coefficient of thermal expansion less than or equal to a thermal expansion coefficient of the ceramic pieces coated with the metallized layer is provided between the metal plated layer coated onto the metallized layer and the metal piston body.
Claim 13
Dependent Claim 26 words
An internal combustion engine piston according to claim 7, wherein each of said plurality of ceramic pieces comprising the ceramic cap have rounded outer peripheral portions.

References Cited (Backward Citations)

JPS5460306A Cited
JPS5848327A Cited
DE3214093A1 Cited
JPS5874853A Cited
US4538562A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1990-03-09 1990-09-08 1991-03-10 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1994-03-09 1994-09-08 1995-03-10 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1998-03-09 1998-09-08 1999-03-10 $7700.00 Window Closed / Lapsed

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