Fabricated piston with sprayed groove

• US 3,914,574 A
• Filed: 10/01/1973
• Issued: 10/21/1975
• Est. Priority Date: 10/01/1973
• Status: Expired due to Term

• Current Assignee: Harold Taylor Hill, Robert Munro
• Original Assignee: Harold Taylor Hill, Robert Munro
• Inventors: Hill, Harold Taylor, Munro, Robert
• Primary Examiner(s): Cohen, Irwin C.
• Application Number:
  US05/402,104
• Time in Patent Office: 750 Days
• Field of Search: 92/213,231,260,222 123/193P 29/156.5R,458,475 277/189.5 219/121EM
• US Class Current: 219/121.14
• CPC Class Codes: B23P 15/10 pistons
• CPC Class Codes: F02F 2003/0061 by welding
• CPC Class Codes: F02F 2200/04 Forging of engine parts
• CPC Class Codes: F02F 3/003 the parts being connected by casting, brazing, welding or clamping
• CPC Class Codes: F16J 9/22 Rings for preventing wear of grooves or like seatings
• CPC Class Codes: Y10T 29/49261 by composite casting or molding
• CPC Class Codes: Y10T 29/49885 with coating before or during assembling

Abstract

This invention relates to a light-metal piston and a method of making the same. The piston having at least one circumferentially-extending ring groove, and is made of at least two parts fastened together, each part defining a part of the piston ring groove and at least one flank of the groove being provided with a wear-resistant coating.

Claims

1. A method of manufacturing a light metal piston having a circumferentially extending piston ring groove, which method comprises the steps of producing a main cylindrical piston part having a reduced diameter portion at its head end, and an annular piston part adapted to fit over said reduced diameter portion, with each of said parts having a lateral surface defining substantially the whole of one side of said piston ring groove when said annular piston part is fitted onto said cylindrical piston part in a predetermined position relative thereto, spraying a wear-resistant coating material onto at least one of said lateral surfaces before said parts are fitted together, and subsequently fitting said parts together in said predetermined position, and electron beam welding them to each other.

2. A method as claimed in claim 1 in which said reduced diameter portion is frusto-conical and tapers inwardly toward the head of said piston.

3. A method as claimed in claim 1 in which said parts have surfaces which mate when said parts are brought into said predetermined position, said mating surfaces including portions which intersect the external surface of the piston but do not intersect the piston ring groove.

4. A method as claimed in claim 1, wherein the wear resistant coating is applied to both side faces of the groove.

5. A method as claimed in claim 1, wherein the annular piston part is of a material having a higher resistance to temperature than the remainder of the piston.

6. A method of manufacturing a light metal piston having a plurality of circumferentially extending piston ring grooves therein, which method comprises the steps of producing a main cylindrical piston part having a reduced diameter portion at its head, and as many annular piston parts adapted to fit over said reduced diameter portion as there are piston ring grooves, with each of said parts having at least one lateral surface defining substantially the whole of one side of a piston groove and each piston groove being defined by surfaces on two different parts when said annular piston parts are fitted onto said cylindrical piston part in predetermined positions relative to the other parts, spraying a wear-resistant coating material onto at least one of the lateral surfaces defining each groove before said parts are fitted together, and subsequently fitting all of said parts together in said predetermined position, and electron-beam welding them to each other.

7. A method as claimeD in claim 6 in which the wear-resistant coating is applied to the side of each groove nearest the head of the piston.