Injector for injecting urea solution into exhaust gas train of internal combustion engine

摘要

The invention relates to an injection device (1), designed in particular for injecting fluid into an exhaust tract of an internal combustion engine, having a valve needle (14), an injection chamber (12) having at least one injection opening (44), and a control chamber (20). The injection device (1) is designed such that a pressure differential between the injection chamber (12) and the control chamber (20) brings about a displacement of the valve needle (14) between an open position in which a fluid flow through the injection opening (44) from the injection chamber (12) is released, and a closed position, in which the injection opening (44) is closed off. The injection chamber (22) and the control chamber (20) are hydraulically connected to an inlet (40, 42; 9), such that a pressure rise in the inlet (40, 42; 9) results in a pressure rise in the injection chamber (12), and a pressure rise in the control chamber (20) delayed in time relative to the pressure rise in the injection chamber (12), and said pressure differential brings about a displacement of the valve needle (14) from the closed position into an open position.