ONE-PIECE PISTON FEATURING ADDITIVE MACHINING PRODUCED COMBUSTION BOWL RIM AND COOLING GALLERY

• US 20180066603A1
• Filed: 09/18/2017
• Published: 03/08/2018
• Est. Priority Date: 03/03/2014
• Status: Active Grant

• Current Assignee: Tenneco Incorporated (Apollo Global Management, Inc.)
• Original Assignee: Federal-Mogul, LLC (Apollo Global Management, Inc.)
• Inventors: EVERS, ROSS, KENNINGLEY, SCOTT, CROMME, WOLFRAM
• Granted Patent: US 10,443,536 B2
• Time in Patent Office: Days
• CPC Class Codes: B22F 10/22 Direct deposition of molten metal
• CPC Class Codes: B22F 10/28 Powder bed fusion, e.g. selective laser melting [SLM] or electron beam melting [EBM]
• CPC Class Codes: B23K 10/027 Welding for purposes other than joining, e.g. build-up welding
• CPC Class Codes: B23K 2101/003 Pistons
• CPC Class Codes: B23K 26/342 Build-up welding
• CPC Class Codes: B23K 9/044 Built-up welding on three-dimensional surfaces
• CPC Class Codes: B23P 15/10 pistons
• CPC Class Codes: B33Y 10/00 Processes of additive manufacturing
• CPC Class Codes: B33Y 80/00 Products made by additive manufacturing
• CPC Class Codes: C23C 4/08 containing only metal elements C23C4/073 takes precedence
• CPC Class Codes: C23C 4/129 Flame spraying
• CPC Class Codes: F02F 2003/0007 Monolithic pistons; One piece constructions; Casting of pistons
• CPC Class Codes: F02F 3/003 the parts being connected by casting, brazing, welding or clamping
• CPC Class Codes: F02F 3/0084 the pistons being constructed from specific materials
• CPC Class Codes: F02F 3/22 the fluid being liquid
• CPC Class Codes: Y02P 10/25 Process efficiency
• CPC Class Codes: Y10T 29/49263 by coating or cladding

Abstract

A piston capable of withstanding high temperatures and extreme conditions of a combustion chamber of an internal combustion engine and manufactured with reduced costs is provided. The method of manufacturing the piston includes casting or forging the bulk of the piston as a single-piece with an open cooling gallery from an economical first material, such as steel, cast iron, or aluminum. The method further includes forming a portion of a combustion bowl surface, which is a small area of the piston directly exposed to the combustion chamber, from a second material by additive machining. The second material has a higher thermal conductivity and higher resistance to oxidation, erosion, and oil coking, compared to the first material. The additive machining process is efficient and creates little waste, which further reduces production costs.

Claims

1. A piston for an internal combustion engine, comprising:

a crown portion and a skirt portion formed from a first material;

a combustion surface disposed along the crown portion, wherein at least a portion of the combustion surface is formed from a second material by an additive machining process; and

a heat affected zone defined by a first edge along the first material and a second edge along the second material, wherein the first edge has a shape following the shape of the second edge.

2. The piston of claim 1, wherein a single piece of the first material forms the crown portion and the skirt portion;

and the second material has at least one of a higher thermal conductivity, higher erosion resistance, higher resistance to coking adhesion, and a higher oxidation resistance than the first material.

3. The piston of claim 1, wherein an underside of the combustion surface includes surface irregularities immediately following the additive machining process and prior to any subsequent machining;

and the second material of the combustion surface includes martensite and tempered martensite in a crystalline structure.