Abstract: There is provided a combustion chamber structure in an internal combustion engine in which, at a peripheral portion of a combustion chamber, a gap between a cylinder head lower face and a piston upper face is small in intake-to-intake and exhaust-to-exhaust zones and gradually increases toward an intake-to-exhaust zone. According to such design, the mixture in the peripheral portion of the combustion chamber can smoothly flow from the intake-to-intake and exhaust-to-exhaust zones to the intake-to-exhaust zone along the peripheral face of the cylinder. The flow of air-fuel mixture from the intake-to-intake zone collides at the center of the intake-to-exhaust zone with the flow of mixture from the exhaust-to-exhaust zone, and the combined flow goes over a conical tapered portion in the upper face of the piston and vigorously enters a central recessed portion thereof. Therefore, it is possible to satisfactorily mix an air-fuel mixture with a simplified configuration.

Abstract: A sealing method wherein sealing agent composition comprises: (A) organopolysiloxane having at least two silicon atom bonded alkenyl groups in one molecule; (B) organohydrogen polysiloxane having at least two silicon atom bonded hydrogen atoms in one molecule; (C) fumed silica of a specified amount with respect to the components (A) and (B); and (D) an inorganic filler of a specified amount with respect to the components (A) and (B), in which the rocker and the cylinder block are pressed such that a hardness of the sealing agent in a cured state is 60 to 80 with a type A durometer of JIS K 6253 and a compression rate of the sealing agent becomes 20 to 40%.

Abstract: There is provided a combustion chamber structure in an internal combustion engine in which, at a peripheral portion of a combustion chamber, a gap between a cylinder head lower face and a piston upper face is small in intake-to-intake and exhaust-to-exhaust zones and gradually increases toward an intake-to-exhaust zone. According to such design, the mixture in the peripheral portion of the combustion chamber can smoothly flow from the intake-to-intake and exhaust-to-exhaust zones to the intake-to-exhaust zone along the peripheral face of the cylinder. The flow of air-fuel mixture from the intake-to-intake zone collides at the center of the intake-to-exhaust zone with the flow of mixture from the exhaust-to-exhaust zone, and the combined flow goes over a conical tapered portion in the upper face of the piston and vigorously enters a central recessed portion thereof. Therefore, it is possible to satisfactorily mix an air-fuel mixture with a simplified configuration.

Abstract: A sealing method wherein sealing agent composition comprises: