US4651631A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Manufacture of pistons
Assignee: AE PLC
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Filing: 1985-05-30
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Granted: 1987-03-24
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Expires: 2005-05-30
Abstract
Abstract A piston is formed in two parts. The main part is formed by gravity die casting from aluminum or aluminum alloy and a second part of the piston is formed by a squeeze casting process to produce a material which is stronger and more resistant than the gravity die cast aluminum or aluminum alloy. At least one piston ring groove is formed in the second part. The two parts are then electron beam welded together to form the complete piston. The squeeze cast portion may be reinforced with whiskers or fibres to further improve its properties. This method of construction has the benefit that only the minimum amount of the piston is formed by the more expensive and time-consuming squeeze casting process so that parts of the piston which do not require the improved properties given by squeeze casting are simply gravity die cast. This is of particular benefit in large diesel pistons.
Inventors
- 👤 Jean-Claude Avezou
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 21:09
CPC Classifications
F; F02; F02F; F02F3/00; F02F3/16; F02F3/20; F02F3/22; B; B23; B23P; B23P15/00; B23P15/10; F02F3/0015; F16; F16J; F16J1/00; F16J1/005; F02F2200/00; F02F2200/04; F05; F05C; F05C2201/00; F05C2201/02; F05C2201/021; Y; Y10; Y10S; Y10S29/00; Y10S29/048; Y10T; Y10T29/00; Y10T29/49; Y10T29/49229; Y10T29/49249; Y10T29/49252; Y10T29/49254; Y10T29/49256; Y10T29/49259; Y10T29/4998; Y10T29/49988
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
362 words
A method of manufacturing a piston for an internal combustion engine comprising: forming a main body portion by a process selected from forging or gravity die casting, said main body portion having an upper end, providing an annular rebate extending around said upper end of the main body portion, providing a combustion bowl insert at the upper end of the main body portion, providing an annular surface extending around said upper surface between said combustion bowl and said annular rebate, forming a second piston portion of annular shape by a squeeze casting process, providing by said process an annular wear-resistant reinforcement in a part of the second piston portion in which a piston ring groove is to be formed, inserting a mass of a temperature-resistant reinforcing material selected from fibres or whiskers into a generally cylindrical lower die part, the mass being spaced from the lower die part, filling the lower die part with molten aluminium alloy, closing the lower die part with an upper die part and solidifying the molten metal in a squeeze casting process, opening the upper die part and removing therefrom a squeeze cast cylindrical third piston portion formed thereby and having a central portion reinforced by the mass, said central portion being surrounded by unreinforced aluminium alloy, machining said third piston portion to form an annular insert having an inner portion formed from said central reinforced portion and defining a combustion bowl entrance, and outer and lower surfaces formed from said unreinforced aluminium alloy, locating said second piston portion in said annular rebate in said first piston portion and then welding said second piston portion to said first piston portion, said second piston portion projecting upwardly beyond said rebate to form a second rebate with said annular surface on said first piston portion, locating said third piston portion in said second rebate and then welding said outer and lower surfaces of said third piston portion to said first piston portion and said second piston portion to form an entrance to said combustion bowl as to provide a piston crown of squeeze cast material, and forming a piston ring groove in said annular reinforcement of said piston portion.
Claim 2
Independent Claim
362 words
A method of manufacturing a piston for an internal combustion engine comprising: forming a main body portion by a process selected from forging or gravity die casting, said main body portion having an upper end, providing an annular rebate extending around said upper end of the main body portion, providing a combustion bowl insert at the upper end of the main body portion, providing an annular surface extending around said upper surface between said combustion bowl and said annular rebate, forming a second piston portion of annular shape by a squeeze casting process, providing by said process an annular wear-resistant reinforcement in a part of the second piston portion in which a piston ring groove is to be formed, inserting a mass of a temperature-resistant reinforcing material selected from fibres or whiskers into a generally cylindrical lower die part, the mass being spaced from the lower die part, filling the lower die part with molten aluminium alloy, closing the lower die part with an upper die part and solidifying the molten metal in a squeeze casting process, opening the upper die part and removing therefrom a squeeze cast cylindrical third piston portion formed thereby and having a central portion reinforced by the mass, said central portion being surrounded by unreinforced aluminium alloy, machining said third piston portion to form an annular insert having an inner portion formed from said central reinforced portion and defining a combustion bowl entrance, and outer and lower surfaces formed from said unreinforced aluminium alloy, locating said second piston portion in said annular rebate in said first piston portion and then welding said second piston portion to said first piston portion, said second piston portion projecting upwardly beyond said rebate to form a second rebate with said annular surface on said first piston portion, locating said third piston portion in said second rebate and then welding said outer and lower surfaces of said third piston portion to said first piston portion and said second piston portion to form an entrance to said combustion bowl as to provide a piston crown of squeeze cast material, and forming a piston ring groove in said annular reinforcement of said piston portion.
Claim 3
Dependent Claim
26 words
A method according to claim 1, wherein the reinforcement of the second piston portion is provided by fibres or whiskers incorporated during said squeeze casting process.
Claim 4
Dependent Claim
30 words
A method according to claim 1, wherein the reinforcement of the second piston portion is provided by an annular insert of a ferrous material incorporated during said squeeze casting process.
Claim 5
Dependent Claim
27 words
A method according to claim 1, wherein the second piston portion defines at least a part of a gallery which extends around the interior of the piston.
Claim 6
Dependent Claim
47 words
A method according to claim 4, wherein the main piston portion provides an annular first part of the gallery and the second piston portion provides an annular second part of the gallery, the complete gallery being formed when the main and second piston portions are welded together.
Claim 7
Dependent Claim
16 words
A method according to claim 1, wherein the welding technique is an electron beam welding technique.
Claim 8
Dependent Claim
10 words
A piston when made by the method of claim 1.
References Cited (Backward Citations)
US2473254A
Cited
US3190273A
Cited
GB1069609A
Cited
GB1075508A
Cited
US3354793A
Cited
GB1097056A
Cited
DE1933520A1
Cited
US3596571A
Cited
GB1277579A
Cited
GB1260599A
Cited
GB1364429A
Cited
GB1441984A
Cited
US3914574A
Cited
DE2701421A1
Cited
DE2726273A1
Cited
US4334507A
Cited
GB1542230A
Cited
WO1979001103A1
Cited
GB2027518A
Cited
DE2930552B1
Cited
GB2090780A
Cited
GB2096932A
Cited
US4498219A
Cited
GB2106433A
Cited
US4548126A
Cited
GB2134021A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-03-23 | 1990-09-22 | 1991-03-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-03-23 | 1994-09-22 | 1995-03-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-03-23 | 1998-09-22 | 1999-03-24 | $7700.00 | Window Closed / Lapsed |