A piston may have an annular body including a crown portion defining a longitudinal axis, a radial direction perpendicular to the longitudinal axis, a plane containing the longitudinal axis and the radial direction, and a contoured combustion bowl. In the plane containing the longitudinal axis and the radial direction, the crown portion includes a radially outer squish surface, and a swirl pocket having a reentrant surface that extends axially downwardly and radially outwardly from the squish surface defining a tangent that forms a reentrant angle with the squish surface that ranges from 33.0 degrees to 37.0 degrees.

Apparatuses, systems and method for utilizing multi-zoned combustion chambers (and/or multiple combustion chambers) for achieving compression ignition (and/or spark-assisted or fuel-assisted compression ignition) in an internal combustion engine are provided. In addition, improved apparatuses, systems and methods for achieving and/or controlling compression ignition (and/or spark-assisted or fuel-assisted compression ignition) in a “Siamese cylinder” internal combustion engine are provided.

An internal combustion engine for gaseous fuel includes a cylinder and a piston for reciprocal movement in the cylinder along a reciprocal axis, whereby a combustion chamber is at least partially delimited by the cylinder and the piston. The piston includes a piston crown facing the combustion chamber, a piston crown projection of the piston crown in a direction parallel to the reciprocal axis and onto a piston crown plane extending transversally to the reciprocal axis having a piston crown center point, the piston crown comprising a piston bowl surface defining a piston bowl and a piston rim portion enclosing the piston bowl surface. A piston bowl opening is the intersection between the piston rim portion and the piston bowl surface. The piston bowl opening has an opening center of gravity in the piston crown plane. The opening center of gravity is offset from the piston crown center point.

The present invention discloses an apparatus for optimizing the fuel/air mixing process of an internal combustion engine. The bottom surface of the cylinder head is provided with a plurality of brackets; a ring is fixed to the brackets; and the ring may be an integrated ring body and may also be composed of a plurality of small segments. The ring is positioned opposite to a fuel injector and located in an area where fuel flows in the combustion chamber. The ring can continuously guides the fuel during the fuel injection process. The ring can be arranged in the liquid-phase region, the gas-liquid two-phase region or the gas-phase region. When the location of the ring interferes with the movement of valves of the internal combustion engine, the part of the ring body that interferes with the movement of the valves can be removed.

The present invention discloses an apparatus for optimizing the fuel/air mixing process of an internal combustion engine. The bottom surface of the cylinder head is provided with a plurality of brackets; a ring is fixed to the brackets; and the ring may be an integrated ring body and may also be composed of a plurality of small segments. The ring is positioned opposite to a fuel injector and located in an area where fuel flows in the the combustion chamber. The ring can continuously guides the fuelduring the fuel injection process. The ring can be arranged in the liquid-phase region, the gas-liquid two-phase region or the gas-phase region. When the location of the ring interferes with the movement of valves of the internal combustion engine, the part of the ring body that interferes with the movement of the valves can be removed.

An internal combustion engine for gaseous fuel includes a cylinder and a piston for reciprocal movement in the cylinder along a reciprocal axis, whereby a combustion chamber is at least partially delimited by the cylinder and the piston. The piston includes a piston crown facing the combustion chamber, a piston crown projection of the piston crown in a direction parallel to the reciprocal axis and onto a piston crown plane extending transversally to the reciprocal axis having a piston crown center point, the piston crown comprising a piston bowl surface defining a piston bowl and a piston rim portion enclosing the piston bowl surface. A piston bowl opening is the intersection between the piston rim portion and the piston bowl surface. The piston bowl opening has an opening center of gravity in the piston crown plane. The opening center of gravity is offset from the piston crown center point.

Internal combustion engines having a split crankshaft are disclosed. The engines may also have non-circular, preferably rectangular, cross-section pistons and cylinders. The pistons may include a skirt with a field of pockets that provide a ringless, non-lubricated, seal equivalent. The pistons also may have a domed piston head with depressions thereon to facilitate the movement of air/charge in the cylinder. The engines also may use multi-stage poppet valves in lieu of conventional poppet valves. The engines may use the pumping motion of the engine piston to supercharge the cylinder with air/charge. The engines also may operate in an inverted orientation in which the piston is closer to the local gravitationally dominant terrestrial body's center of gravity at top dead center position than at bottom dead center position.

A multi-stage combustion engine includes: a pre-compression cylinder including a pre-compression piston operating therein; a combustion cylinder including a combustion piston operating therein. An operating rate of the pre-compression piston is less than an operating rate of the combustion piston.

Operating an internal combustion engine includes conveying fuel of spray plumes of directly injected fuel out of a swirl pocket in a combustion bowl in a piston, and impinging the fuel upon an anti-sooting ramp transitioning between a radially inner shelf surface of the combustion bowl and a radially outer squish surface of the piston. The shelf surface is spaced an axial distance (FA) from a plane defined by the squish surface that is from 1% to 2% of an outer diameter (OD) dimension of the piston. Impinging the fuel upon the anti-sooting ramp directs the fuel upwardly from the squish surface to limit wall-wetting in the combustion cylinder.

Apparatuses, systems and method for utilizing multi-zoned combustion chambers (and/or multiple combustion chambers) for achieving compression ignition (and/or spark-assisted or fuel-assisted compression ignition) in an internal combustion engine are provided. In addition, improved apparatuses, systems and methods for achieving and/or controlling compression ignition (and/or spark-assisted or fuel-assisted compression ignition) in a Siamese cylinder internal combustion engine are provided.