Second pressure ring for Al cylinders and its producing method
AssigneeNippon Piston Ring Co., Ltd.
InventorTakao Toshiaki
Life of this patent
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Abstract
The present invention is for producing stably a second pressure ring which both keeps a lubricant-scraping property and prevents the cylinder side from being longitudinally scratched. According to the invention, a second pressure ring made of iron without plating thereon, of which the outer peripheral sliding surface is downwardly divergent and slanted, is provided in which the lower end of the outer peripheral sliding surface is worked upwardly divergently so as to slant in a range of less than 0.15 mm in its axial direction. The junction between the outer peripheral sliding surface and the slanted worked portion is lapped cylindrically for finishing.
Claims8
A second pressure ring made of iron without plating thereon having an outer periphery and used for A1 cylinders, an outer peripheral sliding surface of the second pressure ring being downwardly divergent so as to slant, wherein said second pressure ring includes, at a lower end of said outer peripheral sliding surface, an oppositely slanting, upwardly divergently worked portion in a range of less than 0.15 mm in its axial direction and a stepped shaped undercut at a lowermost portion of the outer periphery, and a junction between the outer peripheral sliding surface and the oppositely slanting worked portion is lapped for finishing.
A method for producing a second pressure ring made of iron without plating thereon having an outer periphery and used for A1 cylinders, an outer peripheral sliding surface of the second pressure ring being downwardly divergent so as to slant, comprising:
- working upwardly divergently so as to oppositely slant a worked portion at a lower end of the outer peripheral sliding surface of the second pressure ring in a range of less than 0.15 mm in its axial direction, and
- forming a stepped shaped undercut at a lowermost portion of the outer periphery, and
- finishing by lapping cylindrically a junction between the outer peripheral sliding surface and the oppositely slanting worked portion.
A second pressure ring made of iron without plating thereon having an outer periphery and used for A1 cylinders, an outer peripheral sliding surface of the second pressure ring being downwardly divergent so as to slant and a lowermost portion of the outer periphery having a stepped shaded undercut, wherein said outer peripheral sliding surface is buffed, and a lower end of the outer peripheral sliding surface is lapped for finishing.
A method for producing a second pressure ring made of iron without plating thereon having an outer periphery and used for A1 cylinders, an outer peripheral sliding surface of the second pressure ring being downwardly divergent so as to slant and a lowermost portion of the outer periphery having a stepped shaped undercut, comprising:
- buffing the outer peripheral sliding surface, and
- lapping cylindrically a lower end of the outer peripheral sliding surface for finishing.
Dependencies are inferred from the claim text.