Method for metering a reducing agent, method for setting up a control unit for a metering device and motor vehicle having a metering device

摘要

A method for metering a reducing agent from a metering device to an exhaust gas treatment device includes initially determining at least one operating parameter of the metering device. An injector pressure at an injector for feeding the reducing agent into the exhaust gas treatment device is then calculated from the at least one operating parameter. Then, an opening time for the injector is calculated, in which at least the injector pressure determined in step b) is used. The injector is then opened for the opening time calculated in step c). A method for setting up or configuring a control unit for a metering device and a motor vehicle having a metering device are also provided.

主权项

1. A method for metering a reducing agent from a metering device to an exhaust gas treatment device, the metering device having an injector and a delivery unit with a pump and a pressure sensor, the delivery unit and the injector being connected by a line leading from the delivery unit to the injector, the method comprising the following steps:
a) determining at least one operating parameter of the metering device the at least one parameter being a system pressure in the delivery device determined by the sensor and providing the at least one operating parameter to a control unit; b) calculating in the control unit, from the at least one operating parameter, an injector pressure at the injector for feeding the reducing agent into the exhaust gas treatment device while considering at least one of a length of the line, a volume of the line, a diameter of the line, or a flexibility of the line; c) calculating, in the control unit, an opening time and an opening instant for the injector using at least the injector pressure determined in step b); and d) opening the injector for the opening time at the opening instant calculated in step c).