A control device for an engine, the engine includes an exhaust gas control apparatus that is configured to store NOx and react NOx with a reduction agent. The control device includes an electronic control unit. The electronic control unit is configured to: (i) execute a rich spike control, the rich spike control is a control executed to temporarily change an in-cylinder air-fuel ratio from a leaner air-fuel ratio than the stoichiometric air-fuel ratio to the stoichiometric air-fuel ratio or a richer air-fuel ratio than the stoichiometric air-fuel ratio, and (ii) vary an overlap amount of an intake valve and an exhaust valve such that the overlap amount is less during non-execution of the rich spike control than during execution of the rich spike control, in an operation range where a pressure of the intake port becomes higher than a pressure of the exhaust port.

A method and device for operating an internal combustion engine having a supercharging system that has an exhaust turbocharger and an electrically driven compressor. An output of the exhaust turbocharger is adjustable by a control element. A boost pressure setpoint is determined for achieving an increased engine torque setpoint. The supercharging system is adjusted to build up the actual boost pressure in accordance with the boost pressure setpoint and a positive scavenging gradient in a cylinder of the internal combustion engine is adjusted as the overriding command variable for driving the supercharging system.

A method and device for operating an internal combustion engine having a supercharging system that has an exhaust turbocharger and an electrically driven compressor. An output of the exhaust turbocharger is adjustable by a control element. A boost pressure setpoint is determined for achieving an increased engine torque setpoint. The supercharging system is adjusted to build up the actual boost pressure in accordance with the boost pressure setpoint and a positive scavenging gradient in a cylinder of the internal combustion engine is adjusted as the overriding command variable for driving the supercharging system.

In a method, dynamic pressure oscillations in the intake tract or outlet tract of a respective internal combustion engine are measured during normal operation, and from these measured oscillations, a corresponding pressure oscillation signal is generated. A crankshaft phase angle signal is determined at the same time. From the pressure oscillation signal, an actual value of at least one characteristic of at least one selected signal frequency of the measured pressure oscillations in relation to the crankshaft phase angle signal is determined, and the current trimming of the intake tract is determined on the basis of the determined actual value, taking into consideration reference values of the corresponding characteristic of the respectively identical signal frequency for different trimmings of the intake tract.

An air intake device with a variable-length intake duct, comprising: a base duct component with a base duct, configured for the passage of intake air through the base duct component, an extension duct component with an extension duct, configured for the passage of intake air through the extension duct component, a guidance arrangement which guides the extension duct component and the base duct component to relative movement between a first operating position and a second operating position, wherein in the first operating position the base duct and the extension duct form, in mutually prolonging abutment, a continuous duct section, and wherein in the second operating position the extension duct is arranged at a distance from the base duct, and a first centering arrangement which when the duct components approach the first operating position is configured to decrease a radial distance in relation to a virtual base duct path conceived as passing centrally through the base duct between an end section of the base duct facing towards the extension duct component and an end section of the extension duct facing towards the base duct component, wherein the first centering arrangement is configured as separate from the base duct and from the extension duct.

An air intake device with a variable-length intake duct, comprising: a base duct component with a base duct, configured for the passage of intake air through the base duct component, an extension duct component with an extension duct, configured for the passage of intake air through the extension duct component, a guidance arrangement which guides the extension duct component and the base duct component to relative movement between a first operating position and a second operating position, wherein in the first operating position the base duct and the extension duct form, in mutually prolonging abutment, a continuous duct section, and wherein in the second operating position the extension duct is arranged at a distance from the base duct, and a first centering arrangement which when the duct components approach the first operating position is configured to decrease a radial distance in relation to a virtual base duct path conceived as passing centrally through the base duct between an end section of the base duct facing towards the extension duct component and an end section of the extension duct facing towards the base duct component, wherein the first centering arrangement is configured as separate from the base duct and from the extension duct.

A V-type internal combustion engine has a first cylinder bank with four first cylinders and a second cylinder bank with four second cylinders. A first fresh gas line is provided for the first cylinder bank and a second fresh gas line for the second cylinder bank. An exhaust gas system has a first turbocharger, which has a first compressor and a first turbine having two first exhaust gas inlets, and a second turbocharger, which has a second compressor and a second turbine having two second exhaust gas inlets. The first fresh gas line is connectable to the first four cylinders downstream of the first compressor in the flow direction of a fresh gas so as to conduct fresh gas, and the second fresh gas line is connectable to the second four cylinders downstream of the second compressor in the flow direction of the fresh gas so as to conduct fresh gas. A first cylinder and a second cylinder can be connected via the exhaust gas system to the first first exhaust gas inlet, a first cylinder and a second cylinder can be connected via the exhaust system to the second first exhaust gas inlet, a first cylinder and a second cylinder can be connected via the exhaust gas system to the first second exhaust gas inlet, and a first cylinder and a second cylinder can be connected via the exhaust gas system to the second second exhaust gas inlet. A single third compressor is arranged in the first fresh gas line between the first compressor and the first four cylinders.

An internal combustion engine includes a cylinder block including a cylinder, a cylinder head including an intake port, the intake port communicating with the cylinder, an intake manifold fixed to the cylinder head, the intake manifold being configured to supply intake air into the cylinder, and a dynamic vibration absorber configured to suppress vibration of the intake manifold. A direction that is orthogonal to both a central axis of the cylinder and a rotational axis of a crankshaft of the internal combustion engine is defined as a width direction. The dynamic vibration absorber is attached to the intake manifold on an opposite side of a center of gravity of the intake manifold from the cylinder head in the width direction.

The present invention concerns a method in a two-stroke engine comprising at least one cylinder (1) with a reciprocating piston (2), a delimited combustion space (5), at least one outlet port (7) and an inlet port (9) which are both uncovered at the bottom dead center position of the piston, an actuator (8) which activates a valve (17) to open and introduce combustion air via an inlet pipe (6), a control system (15) which controls the actuator to open the valve in order to introduce combustion air via the inlet port. The invention is characterized in that the inlet port is closed by the piston after the outlet port has been closed, thus the opposite compared to the two-stroke engines of today.

A method and device for operating an internal combustion engine having a supercharging system that has an exhaust turbocharger and an electrically driven compressor. An output of the exhaust turbocharger is adjustable by a control element. A boost pressure setpoint is determined for achieving an increased engine torque setpoint. The supercharging system is adjusted to build up the actual boost pressure in accordance with the boost pressure setpoint and a positive scavenging gradient in a cylinder of the internal combustion engine is adjusted as the overriding command variable for driving the supercharging system.