To provide an internal combustion engine, changing only an expansion speed while reducing friction in intake.
The internal combustion engine comprises: an intake/compression cylinder 2 implementing an intake stroke and a compression stroke; a crankshaft 12 functioning as a power output shaft linked with an intake/compression piston 10 in the intake/compression cylinder 2; an expansion/exhaust cylinder 3 implementing an expansion stroke and an exhaust stroke; an auxiliary crankshaft 18 linked with an expansion/exhaust piston 14 in the expansion/exhaust cylinder 3; and a rotation speed ratio change means for rotating the crankshaft 12 at a rotation speed different from that of the auxiliary crankshaft 18. Since the intake/compression stroke and the expansion/exhaust stroke are separated, only the expansion speed is improved while reducing the friction in intake to improve net efficiency.
IWANO HIROSHI
OBA HIROSHI
OTA KENJI
Hiromichi Kobayashi
Tomioka Kiyoshi