Exhaust system for IC engine with catalytic converter has part exhaust gas storage volume with shut-off valve to maintain vacuum and under pressure pump for evacuation

摘要

The engine (1) has an exhaust gas cleaner/catalytic converter (3,5) and a storage volume for part of the exhaust flow after starting the engine. The vacuum in the storage volume (8) is maintained by a shut-off valve (10) when the engine is stopped. An under pressure pump (18) to evacuate the storage volume is connected to it with its intake side. The feed side of the pump is connected to intake unit (11) of the engine, and/or to the exhaust pipe (4') upstream of the exhaust gas cleaner/main catalytic converter (5).