Reagent dosing for a motor exhaust gas cleaning system sets a nominal volume, on a dosing signal, which stays constant until the delivery channel is full to prevent overdosing

摘要

The system delivers a reagent to at least one component (18,19) of the exhaust cleaning system (17) of an internal combustion motor (10), through a connection channel (33) from a dosing unit (30). On receipt of a dosing signal (42), a nominal reagent volume (m Rea Soll) is established and remains constant until the connection channel is full. Or the nominal volume is first set until the channel is filled. The channel filling is monitored by developing pressure (p). The pressure threshold value (p S) matches the opening pressure (P HCIV) of the reagent delivery valve (HCIV) into the exhaust zone (13).