Secondary air introducing device in engine

摘要

A secondary air introducing device for an engine including a cylinder, an associated piston, and a secondary air introducing hole formed in a side wall of the cylinder in such a manner that said hole is located near the bottom dead center of the piston and is opened and closed by the piston. The secondary air introducing hole is made to communicates through inlet passages with the atmosphere, so that the external air is introduced into the cylinder through the secondary air introducing hole by a negative pressure which is produced in the cylinder at the end of a suction stroke of said engine, and a control valve means opened and closed according to variations in load of the engine is provided in the inlet passages, thus controlling an amount of air introduced therein.