CONTROL OF HYDROCARBON EMISSION FROM I.C.ENGINES

摘要

A four-stroke spark ignited internal combustion engine is described which comprises a variable volume working chamber (14) defined between a reciprocating piston (12) having at least one sealing piston ring (20) and a cylinder (10). An auxiliary chamber (16) having a fixed volume significantly smaller than the maximum volume of the working chamber (14) is connected to the working chamber (14) by a passage (18) disposed in the cylinder wall at a position above the top piston ring when the piston (12) is near the bottom of its stroke so that end gases at the end of the power stroke are stored in the auxiliary chamber (16), the auxiliary chamber being connected by the passage (18) to the crankcase when the piston (12) is near the top of its exhaust stroke so that the stored end gases are discharged into the crankcase.