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US 12,037,961 B1Granted
Piston optimized for combustion flame speed and compression ratio in engine system
AssigneeCaterpillar Inc.
InventorsAaron Ness, Andrew J. Loetz, Adam J. Clute, Sri Harsha Uddanda
Life of this patent
Estimating the term…
Abstract
A piston for an internal combustion engine includes a piston skirt and a piston crown attached to the piston skirt and including a combustion face. The combustion face forms a piston rim and a combustion bowl. A bowl edge defines an intersection of the combustion bowl and the piston rim, and a reentrant surface defining a reentrancy angle extends between the bowl edge and a bowl outer wall. A ratio of a bowl depth dimension coincident with the piston center axis to a compression height dimension coincident with the piston center axis is from about 0.30 to about 0.35.
Claims17
A piston for an internal combustion engine comprising:
- a piston skirt having a wrist pin bore formed therein and defining a wrist pin axis;
- a piston crown including a combustion face forming a piston rim extending circumferentially around a piston center axis, and a combustion bowl having a bowl floor extending radially outward of the piston center axis to a bowl outer wall;
- the combustion face further having a bowl edge defining an intersection of the combustion bowl and the piston rim, a reentrant surface extending between the bowl edge and the bowl outer wall, and a cylindrical surface extending between the reentrant surface and the bowl outer wall;
- a bowl depth dimension coincident with the piston center axis is defined between the piston rim and the bowl floor, and a compression height dimension coincident with the piston center axis is defined between the piston rim and the wrist pin axis;
- a bowl max diameter dimension is defined at a location of the cylindrical surface;
- a ratio of the bowl depth dimension to the compression height dimension is from about 0.30 to about 0.35;
- and
- a ratio of the bowl depth dimension to the bowl max diameter dimension is less than the ratio of the bowl depth dimension to the compression height dimension.
5 more elements
A piston for an internal combustion engine comprising:
- a piston skirt having a wrist pin bore formed therein and defining a wrist pin axis;
- a piston crown including a combustion face forming a piston rim extending circumferentially around a piston center axis, and a combustion bowl;
- the combustion face further having a bowl edge defining an intersection of the combustion bowl and the piston rim, and a reentrant surface defining a bowl reentrancy angle;
- the combustion bowl having a U-shaped profile, axially below the reentrant surface, relative to the piston center axis, in a plane including the piston center axis;
- a ratio of a bowl depth dimension coincident with the piston center axis to a compression height dimension coincident with the piston center axis is defined between the piston rim and the wrist pin axis is 0.3 or greater;
- an oil gallery is formed in the piston and extends circumferentially around the piston center axis;
- the combustion face further includes a bowl floor, and a bowl outer wall formed by an arcuate surface extending from the bowl floor, and a cylindrical surface extending from the arcuate surface to the reentrant surface;
- and
- a bowl max diameter dimension is defined at a location of the cylindrical surface axially between an axially uppermost extremity of the oil gallery and the bowl floor;
- and
- a ratio of the bowl depth dimension to the bowl max diameter dimension is less than the ratio of the bowl depth dimension to the compression height dimension.
8 more elements
An internal combustion engine system comprising:
- an engine housing having a cylinder bore formed therein;
- an engine head;
- a piston movable within the cylinder bore between a bottom-dead-center (BDC) position and a top-dead-center (TDC) position;
- the piston including a piston skirt having a wrist pin bore formed therein and defining a wrist pin axis, and a piston crown including a combustion face forming a piston rim extending circumferentially around a piston center axis, and a reentrant combustion bowl;
- a ratio of a bowl depth dimension coincident with the piston center axis to a compression height dimension coincident with the piston center axis is from about 0.30 to about 0.35;
- and
- a clearance volume is defined between the combustion face and the engine head at the TDC position, and a ratio of a combustion bowl volume to the clearance volume is from about 0.70 to about 0.75.
4 more elements
Dependencies are inferred from the claim text.