Multicylinder IC engine with exhaust catalytic converter - uses cylinders periodically to ventilate exhaust until warm=up is complete

摘要

The engine (1) expels combustion prods. through a manifold (2) and exhaust pipe (3) in which a catalytic convertor (4) acts to reduce pollutant emissions. During cold starts, the individually controlled fuel injection valves (5) are closed (8) selectively. During a minority of its power strokes each cylinder acts as a pump, driving sec. air into the exhaust system. The controller (7) switches to normal operation after e.g. 90 s when the convertor (4) has attained its working temp. ADVANTAGES - The weight and cost of exhaust treatment appts. are reduced, and space in the belt drive is saved.