Combustion chamber of an internal combustion engine

Claim 1

An internal combustion engine comprising: a cylinder block having a cylinder bore therein; a cylinder head mounted on said cylinder block and having an inner wall; a first raised portion having on its lower end a flat bottom face and being formed on the periphery of the inner wall of said cylinder head so as to project downwards; a piston reciprocally movable in said cylinder bore and having a top face which has a flat peripheral portion approachable to said flat bottom face so as to create a first squish area therebetween at the end of the compression stroke for spouting out a first squish flow along the top face of said piston, the inner wall of said cylinder head and the top face of said piston defining a combustion chamber therebetween; an intake valve movably mounted on said cylinder head for leading a combustible mixture into said combustion chamber; an exhaust valve movably mounted on said cylinder head for discharging exhaust gas into the atmosphere; a second raised portion formed on the top face of said piston at a position opposite to said first raised portion with respect to an axis of said piston and having a rear face and a front face exposed to said combustion chamber, said rear face being approachable to the inner wall of said cylinder head so as to create a second squish area therebetween at the end of the compression stroke for spouting out a second squish flow which moves forward in the upper interior of said combustion chamber in the direction opposite to the spouting direction of said first squish flow, said first and second squish flows cooperating with each other to create a strong swirl motion rotating about a horizontal axis in said combustion chamber; a spark plug having a spark gap located in said combustion chamber; a first exhaust squish area next to said exhaust valve formed between the flat bottom face next to said exhaust valve of said first raised portion and the flat peripheral portion next to said exhaust valve of said piston; a first intake squish area next to said intake valve formed between the flat bottom face next to said intake valve of said first raised portion and the flat peripheral portion next to said intake valve having a smaller area than said first squish exhaust area; a second exhaust squish area formed from the second squish area being on the opposite side of said exhaust valve from said first exhaust squish area next to said exhaust valve, and; a second intake squish area formed from the second squish area being on the opposite side of said intake valve from said first intake squish area, said second intake squish area having a smaller surface area than said second exhaust squish area.