System For Managing A Reagent Dispensing Device In An Exhaust Line

Abstract

The invention relates to a system for managing a reagent dispensing device in the exhaust line of an engine, said circuit including a tank (1), an injection means (3), a means for conditioning the reagent, sensors capable of determining the representative parameters of the condition of the dispensing circuit and of the reagent, and actuators for controlling the conditioning and injection means driven by a calculation unit based on the condition of the dispensing circuit and of the reagent and on the engine parameters determined by an engine control unit (5) characterised in that the calculation unit is integrated in the engine control unit (5) and in that the system includes an analog / digital interface (4) for processing the analog signals from the sensors (2) and the actuators (3, 7, 8, 9), provided in the vicinity of the tank (1) and connected to the engine control unit by a multiplexed digital link.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]This application is the US National Stage under 35 U.S.C. §371 of International Application No. PCT / FR2008 / 051401 which was filed on Jul. 25, 2008 and which, in turn, claims the priority to French patent application 0756936 which was filed on Aug. 3, 2007, the content of which (description, claims and drawings) is incorporated here by reference.BACKGROUND OF THE INVENTION[0002]The present invention relates to a control system for a reagent dispensing device in an exhaust line.[0003]The pollutants released by the combustion of an automobile engine, whether diesel or gasoline, are mainly unburned hydrocarbons HC, nitrogen oxides (nitrogen monoxide NO and nitrogen dioxide NO2, more generally designated as NOx), carbon oxides (carbon monoxide CO) and solid carbonaceous particles in the case of lean burning diesel engines and direct injection gasoline engines.[0004]Direct injection fuel systems and partial reintroduction of exhaust gas in the ...

AI Technical Summary

Benefits of technology

[0014]The goal of the claimed invention is to propose a simple concept, and consequently, the least expensive in terms of development and assembly cost.

[0019]The control strategy of the treatment device according to the claimed invention is implemented advantageously by specific software integrated in the software of the engine control module. The electronic interface of the invention device simply performs a slave role controlled by the engine control module, which eliminates the need to install a second control module while allowing the elimination of a multitude of electrical wiring harnesses.

[0020]The architecture of the claimed system allows for the connection between the different elements contributing to the treatment of exhaust gas to be simplified significantly.

[0021]In addition, the concept of the system or device simplifies the integration of exhaust gas treatment with the various elements of the automotive vehicle by the absence of a supplementary control unit and by limiting the number of supplementary electrical wires between the different electrical and mechanical elements, which represents significant gains in terms of cost, weight, quality and reliability relative to other concepts.

Problems solved by technology

In commercial vehicles, the treatment of exhaust gas of an internal combustion engine was limited, until now, to the use of catalytic converters for gasoline engines and particulate filters for diesel engines.

To control NOx emissions, gasoline engines are currently using so-called 3-way catalysts, but this type of catalyst loses practically all efficiency if the air-fuel mixture is lean, which is the case for diesel engines.

Since the engine control module is normally located in the engine compartment of an automotive vehicle and the means of the SCR system for treatment of exhaust gas are normally located in the rear of an automotive vehicle, this architecture requires several electrical wiring harnesses running between front and rear of the vehicle, which entails additional weight and significant system cost, namely the cost of developing and manufacturing the electrical wiring harnesses and significant assembly cost.

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