Internal combustion engine and a method of operating an internal combustion engine

Claim 2

An internal combustion engine comprising: a cylinder block having a cylinder bore therein; a piston reciprocally movable in said cylinder bore and having a raised portion which is of substantially flat crescent shape extending radially inwardly from one side thereof; a cylinder head mounted on said cylinder block and having an inner substantially flat crescent shaped surface portion which is coextensive with and faces the raised portion of said piston and defines therewith an immediately closely spaced relation a narrow ignition space between said inner surface portion and the top surface of said piston when said piston reaches the top dead center position, said piston and said cylinder head defining a combustion chamber separate from and in direct fluid communication with said ignition space, means defining a recess in said inner surface portion which extends therein in a direction away from said piston; an intake valve, movably mounted on said cylinder head, through which a combustible fuel mixture is introduced into said combustion chamber; an exhaust valve, movably mounted on said cylinder head, for discharging exhaust gas from said combustion chamber; and ignition means in said recess for igniting the combustible mixture in said ignition space to inject a burning fuel jet from said ignition space into and towards said combustion chamber.

Claim 3

An internal combustion engine comprising: a cylinder block having a cylinder bore therein; a piston reciprocally movable in said cylinder bore and having a raised portion which is of substantially flat crescent shape extending radially inwardly from one side thereof; a cylinder head on said cylinder block and having an inner substantially flat crescent shaped surface portion which is coextensive with and faces the raised portion of said piston and defines therewith an immediately closely spaced relation a narrow ignition space between said inner surface portion and the top surface of said piston when said piston reaches the top dead center position, said piston and said cylinder defining a main combustion chamber therebetween separate from and in direct fluid communication with said ignition space; means defining an auxiliary combustion chamber in said cylinder head, said auxiliary combustion chamber defining means having a surface facing said piston and substantially parallel to said substantially flat raised portion thereof but spaced farther therefrom than said inner portion when said piston is in the top dead center position; an intake valve, movably mounted on said cylinder head, through which a combustible fuel mixture is introduced into said main combustion chamber, said intake valve having a valve head on one end thereof; means defining a first connecting passage directly fluidly communicating said auxiliary combustion chamber and said main combustion chamber and extending therebetween in a direction from said auxiliary combustion chamber to said main combustion chamber and toward and adjacent the radially inner end of said ignition space; means defining a second connecting passage directly fluidly communicating said auxiliary combustion chamber and said main combustion chamber and extending therebetween in a direction from said auxiliary combustion chamber to said main combustion chamber and toward and adjacent said valve head; and an ignition means in one of said auxiliary combustion chamber and said first connecting passage for igniting the combustible mixture in said injection space to inject a burning fuel jet from said injection space into and towards said main combustion chamber.

Claim 4

An internal combustion engine comprising: a cylinder block having a cylinder bore therein; a piston reciprocally movable in said cylinder bore and having a raised portion which is of substantially flat crescent shape extending radially inwardly from one side thereof; a cylinder head on said cylinder block and having an inner substantially flat crescent shaped surface portion which is coextensive with and faces the raised portion of said piston and defines therewith an immediately closely spaced relation a narrow ignition space between said inner surface portion and the top surface of said piston when said piston reaches the top dead center position, said piston and said cylinder defining a main combustion chamber therebetween separate from and in direct fluid communication with said ignition space; means defining an auxiliary combustion chamber in said cylinder head, said auxiliary combustion chamber defining means having a surface facing said piston and substantially parallel to said substantially flat raised portion thereof but spaced farther therefrom than said inner portion when said piston is in the top dead center position; an intake valve, movably mounted on said cylinder head, through which a combustible fuel mixture is introduced into said main combustion chamber, said intake valve having a valve head on one end thereof; means defining a first connecting passage directly fluidly communicating said auxiliary combustion chamber and said main combustion chamber and extending therebetween in a direction from said auxiliary combustion chamber to said main combustion chamber and toward and adjacent the radially inner end of said ignition space; means defining a second connecting passage directly fluidly communicating said auxiliary combustion chamber and said main combustion chamber and extending therebetween in a direction from said auxiliary combustion chamber to said main combustion chamber and toward and adjacent said valve head; and an ignition means in one of said auxiliary combustion chamber and said first connecting passage for igniting the combustible mixture in said injection space to inject a burning fuel jet from said injection space into and towards said main combustion chamber.

Claim 5

An internal combustion engine as claimed in claim 2, wherein a groove is defined in said raised portion at a position whereon the burning jet injected from said first connecting passage into said main combustion chamber directly impinges.

Claim 6

An internal combustion engine as claimed in claim 3, wherein said groove has a vertical side wall arranged at a position near the peripheral edge of the raised portion of said piston.

Claim 7

An internal combustion engine as claimed in claim 3, wherein said groove extends in the circumferential direction of the raised portion of said piston.

Claim 8

An internal combustion engine as claimed in claim 3, wherein a central peak portion is formed in said groove for guiding the burning jet in the circumferential direction of the raised portion of said piston.