SIDE VALVE TYPE INTERNAL COMBUSTION ENGINE

摘要

PURPOSE:To increase the compression ratio and to make it possible to lubricate the sliding surface of a poppet valve by a method wherein a hole in the cylindrical head in which the head of the poppet valve fits and slides is made to communicate with a breather chamber so that the volume of lifting of the valve is excluded from the volume of a combustion chamber. CONSTITUTION:The head 12a of the poppet valve 10 is fitted into the cylindrical hole 15 in the cylinder head so as to slide in the hole and the poppet valve 10 is reciprocated through a cam 6 to thereby establish and interrupt communication between an air intake or exhaust passage 8 and the combustion chamber 7. The communication between the combustion chamber 7 and the cylindrical hole 15 is interrupted at least until the compression stroke of the engine is terminated and the volume 23 of the poppet valve 10 is excluded from the volume of the combustion chamber 7 at the time of termination of the compression stroke to thereby obtain a high compression ratio. The cylindrical hole 15 is made to communicate with the breather chamber 35 through a communication hole 17 so that particles of a lubricating oil is sucked into the cylindrical hole 15 to lubricate the sliding surface of the valve.