Exhaust gas purifying system - has valve device in air channel which opens when cylinder exhaust pressure falls

摘要

The exhaust gas cleaning system is for a four stroke combustion engine where the cylinders (2) are combined as cylinder groups, each of which comprises two cylinders. The opening times of the outlet valves (6,A) in each cylinder group do not overlap. An air channel (14,17,18,19) connects the exhaust channels (12,7) of the cylinders of one group with atmosphere. A valve (13,13') in the air channel automatically opens when the pressure in the cylinder exhaust channels of one group falls below a given value. Consequently air is passed into the exhaust gas channels of the cylinders of this group.