| 摘要 |
The invention relates to a valve unit (9) with purge air pump (7) for use in the fuel tank system (1) of an internal combustion engine (2) with a fuel tank (16) and a storage element (19) for the temporary storage of hydrocarbons (23), wherein the fuel tank (16) and the storage element (5) are connected to one another in such a way that the hydrocarbons (23) which outgas from a fuel (17) which is situated in the fuel tank (16) are stored in the storage element (19), wherein the storage element (19) is connected to the purge air pump (7) which has a suction side (21) and a pressure side (22), wherein fresh air (24) can be conveyed to the storage element (19) by way of the purge air pump (7), as a result of which the hydrocarbons (23) are released from the storage element and are fed to the internal combustion engine for combustion. In order to specify a valve unit (9) with purge air pump (7) which is configured in such a way that the tightness of a fuel tank system can be checked regularly during driving operation of the motor vehicle, the valve unit (9) has a valve cylinder (27) which is mounted in the valve unit (9) such that it can be rotated about the rotational axis (38) thereof, wherein the purge air pump (7) is connected to the valve unit (9) in such a way that, in a first position of the valve cylinder (27), a first valve cylinder passage (31) connects the pressure side (22) of the purge air pump (7) to a first line (29), and a second valve cylinder passage (32) connects the suction side (21) of the purge air pump (7) to a second line (30), and that, in a second position of the valve cylinder (27), a third valve cylinder passage (33) connects the pressure side (22) of the purge air pump (7) to a second line (30), and a fourth valve cylinder passage (34) connects the suction side (21) of the purge air pump (7) to a first line (29). |
