Volvo Personvagnar Ab

Volvo Personvagner Ab

Jan-Erik Larsson

G&ouml;ran Almkvist

Roger Tengblad

Magnus Blomroos

G&ouml;ran Wirmark

Lars Allerv&aring;g

S&ouml;ren Karlsson

Henrik Magn&eacute;

Jan Knutsson

The invention relates to a method of reducing emissions in the exhaust gases from an internal combustion engine that has at least one cylinder to which an air/fuel mixture is supplied when a crankshaft of the internal combustion engine is rotated, at least one inlet valve, at least one inlet duct connecting to the inlet valve, at least one exhaust valve, at least one exhaust duct connecting to the exhaust valve, control members for controlling the opening and closing of the inlet and exhaust valves, and a piston reciprocating between a top dead-center position and a bottom dead-center position in the cylinder. The method comprises the steps of supplying a lean air/fuel mixture to the cylinder, controlling the internal combustion engine so that it works at high load, and controlling the exhaust valve so that it opens when the piston is located in the bottom dead-center position. The exhaust valve is preferably controlled so that it closes after the induction stroke has started. According to one embodiment of the invention, the internal combustion engine is controlled so that the crankshaft rotates at an essentially constant speed within the range of about 1000 to about 2000 rpm.

Method of reducing emissions in the exhaust gases from an internal combustion engine

The invention relates to a device and a method for reducing emissions in catalytic converter exhaust systems for a vehicle provided with a combustion engine. The invention comprises a control unit adapted to control the air-fuel being fed to the engine so that a high concentration of hydrogen is generated in the exhaust gas during start-up of the engine. Furthermore, secondary air is supplied downstream of the engine during cold starting thereof for foaming a gas mixture with the exhaust gas. This gas mixture is oxidized, so that heat energy generated by means of this oxidation is supplied to the catalyst, thereby providing a reduction of the light-off time of the catalyst.

Device and method for reducing emissions in catalytic converter exhaust systems

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Göteborg, Sweden

Jan-Erik Larsson