Piston crown
AssigneePerkins Engines Company Limited
InventorsVivian Page, Rukmangadhan Govindarajan
Life of this patent
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Abstract
The disclosure provides a piston crown for a piston mountable in a combustion cylinder of an internal combustion engine. The piston crown includes a top annular surface. Radially inside the top annular surface is a piston bowl for guiding fuel injected into the combustion cylinder. The piston bowl includes a frusto-conical lip chamfer surface at a throat of the piston bowl next to the annular surface. In diametric cross-section the lip chamfer surface has a radius of at least 30 mm, preferably 30 mm.
Claims15
A piston crown for a piston of an internal combustion engine, the piston crown extending in an axial direction along a central axis and in a radial direction outwardly from the central axis, the piston crown comprising:
- an annular surface at a first end of the piston crown in the axial direction;
- and a piston bowl located radially within the annular surface and recessed relative to the first end of the piston crown;
- wherein the piston bowl comprises:
- a raised floor having an axis of rotation coincident with the central axis of the piston crown, the raised floor comprising a frusto-conical portion tapering, in a direction of the first end of the piston crown towards a spherical cap portion capping the frusto-conical portion;
- an arcuate surface located radially outward relative to the raised floor;
- a circumferential surface parallel to the central axis of the piston bowl at a radially outward end of the arcuate surface;
- and
- a lip chamfer surface extending radially outwardly from the circumferential portion of the arcuate surface and radially inwardly from the annular surface and tapering away from the first end of the piston crown;
- wherein in diametric cross-section the lip chamfer surface has a radius of at least 30 mm, preferably 30 mm.
A method of increasing efficiency of an internal combustion, engine comprising the steps of providing a piston to reciprocate within a cylindrical combustion chamber, the piston comprising a piston crown extending in an axial direction along a central axis and in a radial direction outwardly from the central axis, the piston crown comprising:
- an annular surface at a first end of the piston crown in the axial direction;
- and a piston bowl located radially within the annular surface and recessed relative to the first end of the piston crown;
- wherein the piston bowl comprises:
- a raised floor having an axis of rotation coincident with the central axis of the piston crown, the raised floor comprising a frusto-conical portion tapering in a direction of the first end of the piston crown towards a spherical cap portion capping the frusto-conical portion;
- an arcuate surface located radially outward relative to the raised floor;
- a circumferential surface parallel to the central axis of the piston bowl at a radially outward end of the arcuate surface;
- and
- a lip chamfer surface extending radially outwardly from the circumferential portion of the arcuate surface and radially inwardly from the annular surface and tapering away from the first end of the piston crown;
- wherein in diametric cross-section the lip chamfer surface has a radius of at least 30 mm, preferably 30 mm.
Dependencies are inferred from the claim text.