A piston for use in an internal combustion engine having a two-piece construction including an upper and a lower part. The upper and the lower parts include one or more overlapping cutouts to reduce the weight of the piston. One or more of the cutouts or connecting walls include wall regions that transition to adjacent walls without sharp or abrupt areas. The piston upper and lower parts are permanently joined together. One or more tongue and groove structures are used to provide a locking connection between the piston upper and lower parts.

A piston for use in an internal combustion engine having a two-piece construction including an upper and a lower part. The upper and the lower parts include one or more overlapping cutouts to reduce the weight of the piston. One or more of the cutouts or connecting walls include wall regions that transition to adjacent walls without sharp or abrupt areas. The piston upper and lower parts are permanently joined together. One or more tongue and groove structures are used to provide a locking connection between the piston upper and lower parts.

An internal combustion engine system includes an engine housing having a combustion cylinder, and a piston movable within the combustion cylinder to increase a pressure therein to an autoignition threshold for injected fuel. The piston includes a piston crown having a combustion face forming a combustion bowl, and varied in profile to form jet-jet interaction limiters at locations offset from fuel spray jet paths from a fuel injector. The jet-jet interaction limiters include a bowl component and a step component protruding, respectively, within the combustion bowl and a step located transitioning between the combustion bowl and a circumferential rim of the piston. Limiting jet-jet interaction limits soot production in exhaust produced by the engine.

An internal combustion engine system includes an engine housing having a combustion cylinder, and a piston movable within the combustion cylinder to increase a pressure therein to an autoignition threshold for injected fuel. The piston includes a piston crown having a combustion face forming a combustion bowl, and varied in profile to form jet-jet interaction limiters at locations offset from fuel spray jet paths from a fuel injector. The jet-jet interaction limiters include a bowl component and a step component protruding, respectively, within the combustion bowl and a step located transitioning between the combustion bowl and a circumferential rim of the piston. Limiting jet-jet interaction limits soot production in exhaust produced by the engine.

An internal combustion engine includes a hollow cylinder, a piston within the hollow cylinder, and a cylinder head. A base valve assembly at a base of the hollow cylinder permits or restricts fluid flow from an intake manifold into a sub-chamber below the piston. The piston includes at least one intake port connecting a combustion chamber above the piston with the sub-chamber, and a transfer valve that opens and closes the at least one intake port. When the transfer valve opens the at least one intake port, fluid is permitted to flow from the sub-chamber to the combustion chamber. The internal combustion engine operates according to a four-stroke piston cycle, wherein multiple intake stages are provided. The intake stages may include intake of air into the sub-chamber during a compression stroke, transfer of air from the sub-chamber to the combustion chamber during a power stroke, intake of air-fuel mixture into the sub-chamber during an exhaust stroke, and transfer of air-fuel mixture from the sub-chamber to the combustion chamber during an intake stroke.

An internal combustion engine includes a hollow cylinder, a piston within the hollow cylinder, and a cylinder head. A base valve assembly at a base of the hollow cylinder permits or restricts fluid flow from an intake manifold into a sub-chamber below the piston. The piston includes at least one intake port connecting a combustion chamber above the piston with the sub-chamber, and a transfer valve that opens and closes the at least one intake port. When the transfer valve opens the at least one intake port, fluid is permitted to flow from the sub-chamber to the combustion chamber. The internal combustion engine operates according to a four-stroke piston cycle, wherein multiple intake stages are provided. The intake stages may include intake of air into the sub-chamber during a compression stroke, transfer of air from the sub-chamber to the combustion chamber during a power stroke, intake of air-fuel mixture into the sub-chamber during an exhaust stroke, and transfer of air-fuel mixture from the sub-chamber to the combustion chamber during an intake stroke.

A piston for an internal combustion engine includes a piston having a bowl surface forming a combustion bowl, a rim surface forming an annular rim, and a gallery surface exposed to a backside cooling gallery of the piston. The bowl surface forms a bowl profile varied circumferentially around a piston center axis, and the gallery surface forms a gallery profile that is varied circumferentially around the piston center axis and is congruous with the bowl profile. The gallery surface is concave to the combustion bowl, convex to the backside cooling gallery, and forms no edges exposed within the backside cooling gallery. A wall formed between the combustion bowl and the backside cooling gallery has a heat-dissipation wall thickness defined by the varied bowl profile and the varied gallery profile.

A piston for an internal combustion engine includes a piston having a bowl surface forming a combustion bowl, a rim surface forming an annular rim, and a gallery surface exposed to a backside cooling gallery of the piston. The bowl surface forms a bowl profile varied circumferentially around a piston center axis, and the gallery surface forms a gallery profile that is varied circumferentially around the piston center axis and is congruous with the bowl profile. The gallery surface is concave to the combustion bowl, convex to the backside cooling gallery, and forms no edges exposed within the backside cooling gallery. A wall formed between the combustion bowl and the backside cooling gallery has a heat-dissipation wall thickness defined by the varied bowl profile and the varied gallery profile.

A one-piece cast piston (10) for an internal combustion engine includes a cooling channel (12) and at least one rib (18) on the inner side of the piston opposite the recess base of a combustion bowl (14).

A one-piece cast piston (10) for an internal combustion engine includes a cooling channel (12) and at least one rib (18) on the inner side of the piston opposite the recess base of a combustion bowl (14).