Volvo Car Corporation

Volvo Personvagner Ab

G&ouml;ran Almkvist

Karin Thorn

Krister Fredriksson

Jan-Erik Larsson

Lars Allerv&aring;g

Sten Sj&ouml;str&ouml;m

Jan Knutsson

Lars Allev&aring;g

Ingemar Bredstr&ouml;m

Henrik Magn&eacute;

A method of reducing emissions in the exhaust gases of an internal combustion engine is disclosed. The engine includes at least one cylinder supplied with an air/fuel mixture when a crankshaft of the internal combustion engine rotates, at least one intake valve, at least one exhaust valve, control members for controlling the opening and closing of the intake and exhaust valves, and a piston reciprocating between a top dead-center position and a bottom dead-center position in the cylinder. The method includes supplying an air/fuel mixture with a lambda value greater than 1 to the cylinder, controlling the intake valve so that it opens after the piston has passed the top dead-center position, controlling the exhaust valve so that it opens before the piston has passed the bottom dead-center position, and controlling the exhaust valve so that it closes before the intake valve opens.

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

A method of reducing emissions in the exhaust gases of 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 intake valve, at least one exhaust valve, and a piston reciprocating between a top dead-center position and a bottom dead-center position in the cylinder. The method comprises the following steps: an air/fuel mixture with a lambda value greater than 1 is supplied to the cylinder, an electric motor/generator connected to the crankshaft maintains an essentially constant predetermined speed of the crankshaft, and the exhaust valve is controlled so that it opens before the piston has passed the bottom dead-center position is disclosed.

Method of reduction emissions in the exhaust gases of an internal combustion engine

The invention discloses a method of reducing emissions in the exhaust gases of an internal combustion engine having at least one cylinder to which an air/fuel mixture is supplied when a crankshaft of the internal combustion engine rotates, at least one inlet valve, at least one 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 includes the steps of supplying an air/fuel mixture with lambda value greater than 1 to the cylinder, controlling the internal combustion engine so that it works at high load, and controlling the inlet valve so that it opens after the piston has passed the top dead-center position. According to an embodiment of the invention, the internal combustion engine is controlled so that the crankshaft rotates at an essentially constant speed within a range of about 1000 to about 2000 rpm.

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

A method for reducing harmful and toxic exhaust gases from an internal combustion engine. The engine includes at least one cylinder to which an air/fuel mixture is supplied when a crankshaft of the internal combustion engine is rotated. The method includes supplying an air/fuel mixture with a lambda value greater than one to the cylinder, and controlling the pressure in the intake channel by an electric motor/generator coupled to the crankshaft. When the pressure in the intake channel exceeds a predetermined pressure, the electric motor/generator is controlled in such a way that the pressure in the intake channel can decrease, and when the pressure in the intake channel falls below a predetermined pressure, the electric motor/generator is controlled in such a way that the pressure in the intake channel can increase.

Method of reduction of exhaust gas emissions from internal combustion engines

Method of reducing noxious or toxic exhaust emissions from an internal combustion engine ( ) having a plurality of cylinders ( ) cooperating with a crankshaft ( ) to cause the crankshaft to rotate at a rotational speed when the cylinders ( ) are provided with an air/fuel mixture having a lambda value and the mixture is ignited to generate pressure in the cylinders. The method includes measuring a parameter reflecting the pressure in a first cylinder during at least a part of a working stroke of the first cylinder when supplied with an air/fuel mixture having a first lambda value to thereby obtain a first parametric value. An air/fuel mixture is provided to a second cylinder, which air/fuel mixture has a second lambda value which is different to the first lambda value, to cause the second cylinder to perform a working stroke. A parameter is measured reflecting the pressure in the second cylinder during at least a part of the working stroke of the second cylinder to obtain a second parametric value. The parametric values are compared to obtain a parametric comparison value and the lambda value is adjusted for the air/fuel mixture to a subsequent cylinder dependent on the parametric comparison value.

Growing community of inventors

Gråbo, Sweden

Göran Almkvist

Growing community of inventors

Gråbo, Sweden

G&ouml;ran Almkvist

Göran Almkvist