Piston-type internal combustion engine

Abstract

A piston-type internal combustion engine (10) having an intake line (20) for delivering air to combustion chambers of the engine and an exhaust system (15, 22) for removing exhaust gases from said combustion chambers. The exhaust system includes equipment (29, 30) for reducing environmentally harmful exhaust emissions from the engine, which is intended to function with variable load in order to propel a vehicle. The exhaust system (15, 22) has a branch pipe (26) controlled by a valve (24) and bypassing at least one part of the equipment (29, 30) for reducing environmentally harmful exhaust emissions. The valve (24) is controlled so that it leads the exhaust gas flow through the branch pipe (26) over a part of the overall load range of the engine. The engine is optimized in order to give acceptable exhaust emissions over said part of the overall load range of the engine.

Dependencies are inferred from the claim text.