Tank ventilation system installed in engine of motor vehicle, has bypass line that is provided with shut-off valve that is opened and closed during flushing of buffer while parking vehicle so that ambient air is passed into engine

摘要

The system has natural vacuum leak detection (NVLD) unit (6) that is provided with valve unit for opening and closing intake tract (2a) of the engine (2). A purge line (8) has buffer (4) via which volatile hydrocarbons from fuel tank (1) is escaped after parking the vehicle on sufficient tightness by formation of vacuum with respect to fuel tank. A bypass line (10) has shut-off valve (11) that is provided between fuel tank and surroundings, and configured to open and close during flushing of buffer while parking the vehicle so that ambient air is passed into engine.