Double bowl piston

A piston for an internal combustion engine, comprising:

• a piston crown having a face;
• a first piston bowl recessed within the face of the piston crown, the first piston bowl having a bottom surface and the greatest diameter at the face of the piston crown;
• a second piston bowl centrally located and having an upper edge located below the face of the piston crown;
• and
• an internal annular cooling passageway entirely disposed radially outward of the greatest diameter of the second piston bowl.

A piston for an internal combustion engine, comprising:

• a piston crown having a face;
• a first piston bowl having a bottom surface and being recessed within the face of the piston crown;
• a second piston bowl centrally located and having an upper edge located below the face of the piston crown;
• and
• an internal annular cooling passageway having the greatest diameter greater than the greatest diameter of the second piston bowl and less than the greatest diameter of the first piston bowl.

A method of operating an internal combustion engine having at least one cylinder and a piston slidably disposed within the at least one cylinder, the method comprising:

• moving the piston toward a top dead center position during a compression stroke;
• injecting fuel into a first piston bowl recessed within a face of the piston, the first piston bowl having a single bottom surface and an outer annular wall, a line extending from an interior annular edge of the face of the piston and tangent with the outer annular wall forming an interior angle greater than 90 degrees with the face of the piston;
• injecting fuel against a bottom curved surface of a protrusion of a second piston bowl that extends upward relative to the single bottom surface of the first piston bowl, wherein the second piston bowl is centrally located and the upwardly extending protrusion is located below the face of the piston crown;
• and
• directing a cooling medium through the piston.

An internal combustion engine, comprising:

• an engine block defining a plurality of cylinders;
• and
• a piston crown disposed within each of the plurality of cylinders and having:
• a face having an interior annular edge;
• a first piston bowl recessed within the face of the piston crown, the first piston bowl having a single bottom surface and an outer wall, a line extending from the interior annular edge of the face and tangent with the outer wall forming an interior angle with the face of the piston crown greater than 90 degrees;
• and
• a second piston bowl recessed within the single bottom surface of the first piston bowl, and having an annular concave portion, a central convex portion, and an annular wall portion disposed between the first and second piston bowls and protruding upward relative to the single bottom surface of the first piston bowl, wherein the contour of the concave and convex portions of the second piston bowl substantially match the contour of a bottom interior surface of the piston crown.

A piston for an internal combustion engine, comprising:

• a piston crown having a face;
• a first piston bowl recessed within the face of the piston crown, the first piston bowl having a bottom surface and an outer wall;
• and
• a second piston bowl recessed within the bottom surface of the first piston bowl,
• wherein every surface of the first and second piston bowls has curvature.

A piston for an internal combustion engine, comprising:

• a piston crown having a face with an interior annular edge;
• a first piston bowl recessed within the face of the piston crown, the first piston bowl having a bottom surface and an outer wall, a line extending from the interior annular edge of the face and tangent with the outer wall forming an interior angle with the face of the piston crown greater than 90 degrees;
• and
• a second piston bowl centrally disposed and having an upper edge located below the face of the piston crown,
• wherein the interior annular edge is rounded and joins the face of the piston crown and the first piston bowl.

A piston for an internal combustion engine, comprising:

• a piston crown having a face;
• a first piston bowl recessed within the face of the piston crown, the first piston bowl having a bottom surface and an outer wall;
• a second piston bowl recessed within the bottom surface of the first piston bowl;
• and
• an internal annular cooling passageway having an upper portion substantially co-planar with a bottom surface of the second piston bowl.

A piston for an internal combustion engine, comprising:

• a piston crown having a face;
• a first piston bowl recessed within the face of the piston crown, the first piston bowl having a bottom surface and an outer wall;
• and
• a second piston bowl having an annular concave portion, a central convex portion, and an annular wall portion disposed between the first and second piston bowls and protruding upward relative to the single bottom surface of the first piston bowl, wherein the contour of the concave and convex portions of the second piston bowl substantially match the contour of a bottom interior surface of the piston crown.