| 摘要 |
The invention relates to a metering apparatus for introducing a reductant into an exhaust pipe of an internal combustion engine, wherein the metering apparatus has a metering module (1) having a metering valve (3) and the metering module (1) is connected to a conveying apparatus (9) by means of a pressure line (10) and the metering apparatus has an apparatus for returning reductant from the reductant valve (3) at least into the pressure line (7). According to the invention, a metering apparatus is provided, by means of which a reliable return of reductant from the metering apparatus (3) at least into the pressure line (10) can be provided in order to achieve the ice-pressure robustness of the metering valve (3) after a switch-off of a vehicle with emergency stop (ADR function) with an interruption of the electrical power supply after less than 1 s at metering valve temperatures in particular greater than 100 °C. This is achieved in that the metering module has a check valve (2), which is connected to the surroundings and blocks in the flow direction to the surroundings and has an inlet-side throttle (13). |
