Volkswagen Ag

Robert Boschgmbh

Burkhard Veldten

Maciej Kulaszewski

Nestor Rodriguez-Amaya

Andreas Dutt

Walter Fuchs

Michael Daetz

Andreas Kerst

Dietmar Ottenbacher

Bodo Hoffmann

Holger Loof

Ruben-Sebs Henning

Iris Sauerwein

Stefan Becher

Ines Matteg

Frank Alich

Volker Gehrke

Jens Fricke

Thorsten Lange

Klemens Brack

The invention relates to a method and to a motor vehicle for diagnosing an exhaust gas catalytic converter (), which is arranged in an exhaust gas tract () of an internal combustion engine () and is suitable for converting at least one exhaust gas component, wherein the exhaust gas tract () has an exhaust gas sensor () arranged upstream of the exhaust gas catalytic converter () and has an exhaust gas recirculation system (), which is designed to remove at least part of the exhaust gas from an exhaust gas duct () of the exhaust gas tract () downstream of the exhaust gas catalytic converter () and to feed the removed exhaust gas to the internal combustion engine (). The method comprises the following steps: measuring a first concentration (NOX) of the exhaust gas component upstream of the exhaust gas catalytic converter () by means of the exhaust gas sensor () during fueled operation of the internal combustion engine (), recirculating at least part of the exhaust gas by means of the exhaust gas recirculation system () during unfueled overrun of the internal combustion engine (), measuring a second concentration (NOX) of the exhaust gas component by means of the exhaust gas sensor () during the unfueled overrun of the internal combustion engine (), and determining a state of the exhaust gas catalytic converter () in dependence on the first and second concentrations (NOX, NOX) of the exhaust gas component.

Method for diagnosing an exhaust gas catalytic converter, and motor vehicle

A method for diagnosing an exhaust-gas catalytic converter () arranged in an exhaust-gas system () of an internal combustion engine () for the catalytic conversion of at least one exhaust-gas component from the internal combustion engine (), which has an exhaust-gas recirculation means with which a partial stream of the exhaust gas can be drawn off downstream of the catalytic converter () and fed into the combustion air of the internal combustion engine (), involves determining the current raw emission (NOraw) of the internal combustion engine () in of the exhaust-gas component; measuring the current concentration of the exhaust-gas component (NOmeas) in the exhaust gas upstream of the catalytic converter (); and determining a diagnostic value for the catalytic converter () in terms of the conversion of the exhaust-gas component as a function of the modelled raw emission (NOraw) from the internal combustion engine () and the measured concentration of the exhaust-gas component (NOmeas). The invention further relates to a diagnostic device configured to perform the method and a motor vehicle having such a device.

Method for diagnosing an exhaust gas catalytic converter, diagnosis device and motor vehicle having such a device

A method of testing the functionality of an oxidation catalytic converter of an internal combustion engine, particularly a diesel engine, of a motor vehicle, includes the following steps: (a) verifying whether the motor vehicle is at a standstill; (b) verifying whether the internal combustion engine is idling; (c) verifying whether a temperature lies within a predetermined range upstream and downstream of the oxidation catalyst. Then, if all of the steps (a) to (c) yield an affirmative result, an intervention in the engine management is made in such a way that a predetermined temperature is set in the oxidation catalyst; (e) hydrocarbons (HCs) are actively produced by post-injecting fuel at a late point in time; (f) a lambda value is measured upstream and downstream of the oxidation catalyst as soon as the predetermined temperature from step (d) has been reached, and while HCs are actively produced in step (e). Then, a difference is determined between the lambda values measured upstream and downstream of the oxidation catalyst. If the difference is less than a predetermined value, a conclusion is reached that the oxidation catalyst is damaged.

Method for testing the functionality of an oxidation catalyst of an internal combustion engine

For determining the exhaust gas recirculation mass flow and the exhaust gas recirculation rate of an internal combustion engine () dependent on this, it is proposed, while said internal combustion engine () is in operation, to adapt a characteristic curve, determined before said internal combustion engine () is initially started up, representing the cylinder mass flow (dm) supplied to the cylinders of said internal combustion engine (), which is composed of the fresh air mass flow (dm) and the exhaust mass flow recirculated via an exhaust gas recirculation pipe (), to said fresh air mass flow (dm), known for various operating points of said internal combustion engine. The exhaust gas recirculation mass flow (dm) is then determined as a function of said fresh air mass flow (dm), measured at a particular transient operating point of said internal combustion engine, using the adapted characteristic curve of said cylinder mass flow (dm).

Method and device for determining the exhaust gas recirculation mass flow of an internal combustion engine

In a method and a device for controlling the injection of fuel into an internal combustion engine, a distinction is made at least between a first state and a second state. Immediately before the transition from the first state to the second state, the injection data is altered so that the emissions, in particular the production of noise, are gradually made to approximate the emissions in the second state.

Method and device for control of the fuel injection in an internal combustion engine

In a fuel injection pump of the distributor type, a solenoid valve is provided in the distributor and the valve member of this solenoid valve is supported in an axial bore of the distributor and actuated by a magnet fixed to the housing in order to block the connection between a pump working space of the distributor-type injection pump and a relief space during an intended high-pressure injection phase. Inherent in its construction, a distributor of such a fuel injection pump has a certain axial play in its mounting and this has an effect on the actuating travel of the valve member in the distributor in relation to the fixed electromagnet. In order to avoid changes in the magnetic properties, which can arise due to this axial association, part of the magnetic circuit in the form of a magnet plate is displaceable together with the distributor, with the result that the position of an armature connected firmly to the valve member relative to this part of the magnet core, with which it forms the working air gap, does not change depending on the axial position of the distributor, and the magnetic properties of the solenoid valve are thus maintained irrespective of the axial position of the distributor.

Fuel injection pump for an internal combustion engine

Growing community of inventors

Edemissen, Germany

Burkhard Veldten