Assembly and method for introducing a reducing agent into the exhaust pipe of an exhaust system of an internal combustion engine

摘要

An assembly (10) for introducing a reducing agent into the exhaust pipe (12) of an exhaust system of an internal combustion engine, in particular of a motor vehicle, has a feed connector (14) which opens into the exhaust pipe (12) and includes a wall (16), a feed device (20) for reducing agents which opens into the feed connector (14), and a device (22) for generating a gas flow (G) which is additional to the reducing agent flow (R) and lines the wall (16) of the feed 10 connector (14). Furthermore, there is described a method of introducing a reducing agent into the exhaust pipe (12) of an exhaust system of an internal combustion engine, in particular of a motor vehicle.

主权项

1. A reducing agent injection apparatus for us exhaust system with a catalytic converter, the apparatus comprising
an exhaust pipe formed to include an exhaust passageway adapted to conduct exhaust gas to the catalytic converter and formed to include a side aperture opening into exhaust passageway, a feed connector arranged to extend through the side aperture into the exhaust passageway of the exhaust pipe, the feed connector upstream of the catalytic converter including an inlet end formed to include an inlet aperture ad to receive a flow of reducing agent comprising an aqueous urea solution from a reducing agent source, an outlet end formed to include an outlet aperture and coupled to the exhaust pipe to the outlet aperture to open into the exhaust passageway, and an inner surface arranged to exit from the inlet end to the outlet end to define a feed-connector channel extending from the inlet end to the outlet end, and a guide arranged in the feed-connector channel configured to communicate the flow of reducing agent passing through the inlet aperture of feed-connector into the exhaust passageway via a reducing-agent passageway to combine with exhaust gas S flowing through the exhaust passageway in a downstream direction toward the catalytic converter, wherein the guide includes an inner surface arranged to define the red agent passageway and an outer surface arranged to cooperate with a surrounding portion of inner surface of the feed connector to define therebetween a gap configured to conduct a flow of deposit-blocking gas that is at least largely free of reducing agent the inner surface of the feed connector to block deposition of matter entrained in the flow of reducing agent on or along the inner surface of the feed connector and an inner surface of the exhaust pipe bounding the exhaust passageway.