A reciprocating combustion engine includes at least one cylinder, in which a reciprocating piston is arranged back and forth movable. The reciprocating combustion engine includes a pin structure arranged on the combustion chamber side in the area of the cylinder head or the piston bottom. Due to the pin structure, local peak temperatures can be avoided during the combustion process, so that NOx emissions can be avoided or at least greatly reduced. A motor vehicle, for example a commercial vehicle, includes a reciprocating combustion engine.

A reciprocating combustion engine includes at least one cylinder, in which a reciprocating piston is arranged back and forth movable. The reciprocating combustion engine includes a pin structure arranged on the combustion chamber side in the area of the cylinder head or the piston bottom. Due to the pin structure, local peak temperatures can be avoided during the combustion process, so that NOx emissions can be avoided or at least greatly reduced. A motor vehicle, for example a commercial vehicle, includes a reciprocating combustion engine.

An internal combustion engine includes a piston and a fuel injection valve. The fuel injection valve includes a first injection hole, a second injection hole, a first needle configured to open and close the first injection hole, and a second needle configured to open and close the second injection hole. The first injection hole and the second injection hole are configured such that a portion of a fuel spray injected from the first injection hole and a portion of a fuel spray injected from the second injection hole overlap each other at a position apart at a predetermined distance from a side wall of a cavity of the piston. The second needle is configured to start operation in order to open the second injection hole after a predetermined time has elapsed from a point of time when the first needle starts operation in order to open the first injection hole.

An internal combustion engine includes a piston and a fuel injection valve. The fuel injection valve includes a first injection hole, a second injection hole, a first needle configured to open and close the first injection hole, and a second needle configured to open and close the second injection hole. The first injection hole and the second injection hole are configured such that a portion of a fuel spray injected from the first injection hole and a portion of a fuel spray injected from the second injection hole overlap each other at a position apart at a predetermined distance from a side wall of a cavity of the piston. The second needle is configured to start operation in order to open the second injection hole after a predetermined time has elapsed from a point of time when the first needle starts operation in order to open the first injection hole.

A fuel injection valve has first injection holes, second injection holes, a first needle that opens and closes the first injection holes, and a second needle. The fuel injection valve is arranged such that a part of fuel injected from the first injection hole and a part of fuel injected from the second injection hole are gathered together at a position spaced from the side wall of the cavity by a predetermined distance. The second needle starts operating to open the second injection holes, after a predetermined time elapses from a point in time at which the first needle starts operating to open the first injection holes.

A fuel injection valve has first injection holes, second injection holes, a first needle that opens and closes the first injection holes, and a second needle. The fuel injection valve is arranged such that a part of fuel injected from the first injection hole and a part of fuel injected from the second injection hole are gathered together at a position spaced from the side wall of the cavity by a predetermined distance. The second needle starts operating to open the second injection holes, after a predetermined time elapses from a point in time at which the first needle starts operating to open the first injection holes.

This piston includes a low thermal conductivity part comprising: a porous member made of a borosilicate glass that has a lower thermal conductivity than the piston base material made of an aluminum alloy material that is the base material impregnated into the porous member. A molded object obtained from a first powder (glass powder) and a second powder (sodium chloride powder) is put in hot water to dissolve away the second powder and form pores in the porous member. The aluminum alloy material is impregnated into these pores to unite the porous member to the piston base material. Furthermore, varnish containing polyimide, etc. is applied to the upper surface of the porous member and impregnated into the pores with a varnish impregnation device assisted by vacuum drawing and atmospheric pressure, thereby preventing the pores from remaining vacant. Due to this, deterioration in exhaust emission performance can be prevented.

An engine includes a cylinder block in which a cylinder is formed, a piston arranged to be reciprocally movable in the cylinder, a cylinder head that is arranged on an upper side of the cylinder block and forms a combustion chamber between an inner peripheral surface of the cylinder and an upper surface of the piston, and an ignition plug arranged in the cylinder head. An inner peripheral portion of the cylinder head includes an inner peripheral side portion formed to be flush with the inner peripheral surface of the cylinder, and a tilting portion tilting from the upper surface of the piston to a side surface is formed on the piston.

An engine includes a cylinder block in which a cylinder is formed, a piston arranged to be reciprocally movable in the cylinder, a cylinder head that is arranged on an upper side of the cylinder block and forms a combustion chamber between an inner peripheral surface of the cylinder and an upper surface of the piston, and an ignition plug arranged in the cylinder head. An inner peripheral portion of the cylinder head includes an inner peripheral side portion formed to be flush with the inner peripheral surface of the cylinder, and a tilting portion tilting from the upper surface of the piston to a side surface is formed on the piston.

An internal combustion engine with a piston having a piston head with a resonance cavity opening onto the head, and where a fuel nozzle located in a cylinder head is positioned to inject a fuel such as natural gas into the combustion chamber where resonance formed within the resonance cavity will ignite the fuel without the need of a spark plug. Inlet and exhaust ports in the cylinder head allow for air and combustion gas enter or leave the combustion chamber.