A compression-release engine brake system for effectuating a compression-release engine braking operation of an internal combustion engine. The compression-release system includes a lost motion exhaust rocker assembly including an exhaust rocker arm, an actuation device including an actuation piston and an actuation cavity, and a reset device including a reset check valve and a slider-piston. Hydraulic fluid in the exhaust rocker arm is locked in the actuation cavity when the reset check valve is in the closed position, and flows through the reset check valve when the reset check valve is in the open position. The slider-piston is associated with the reset check valve so that in an extended position of the slider-piston the reset check valve is free to move toward the closed position, and in a retracted position of the slider-piston the reset check valve is moved to the open position thereof by the slider-piston.

An engine valve actuation mechanism for producing a variable engine valve event includes a cam, a rocker arm, a rocker arm shaft, an eccentric rocker arm bushing, and a bushing actuation device. The eccentric rocker arm bushing is disposed in an axial hole in the rocker arm, the rocker arm shaft being disposed in the eccentric rocker arm bushing with the rocker arm shaft and the eccentric rocker arm bushing having offset axial centerlines. One end of the rocker arm and the cam is connected to form a kinematic pair and the other end of the rocker arm is located above the engine valve with a gap between the cam and the engine valve. The bushing actuation device is placed in the rocker arm and drives the eccentric rocker arm bushing to rotate, and the rotation of the eccentric rocker arm bushing changes the gap to generate the variable engine valve event.

An engine valve actuation mechanism for producing a variable engine valve event includes a cam, a rocker arm, a rocker arm shaft, an eccentric rocker arm bushing, and a bushing actuation device. The eccentric rocker arm bushing is disposed in an axial hole in the rocker arm, the rocker arm shaft being disposed in the eccentric rocker arm bushing with the rocker arm shaft and the eccentric rocker arm bushing having offset axial centerlines. One end of the rocker arm and the cam is connected to form a kinematic pair and the other end of the rocker arm is located above the engine valve with a gap between the cam and the engine valve. The bushing actuation device is placed in the rocker arm and drives the eccentric rocker arm bushing to rotate, and the rotation of the eccentric rocker arm bushing changes the gap to generate the variable engine valve event.

On the basis of absolute values α and β of variations, before and after actuation of an exhaust brake, of fuel-injection and intake-air amounts, respectively, an exhaust brake is determined to normally operate when the absolute values α and β of the variations of the fuel-injection and intake-air amounts are not less than fuel-injection and intake-air variation thresholds, respectively; the exhaust brake is determined to have failure when the absolute values α and β of the variations of the fuel-injection and intake-air amounts are less than the fuel-injection and intake-air variation thresholds, respectively.

On the basis of absolute values α and β of variations, before and after actuation of an exhaust brake, of fuel-injection and intake-air amounts, respectively, an exhaust brake is determined to normally operate when the absolute values α and β of the variations of the fuel-injection and intake-air amounts are not less than fuel-injection and intake-air variation thresholds, respectively; the exhaust brake is determined to have failure when the absolute values α and β of the variations of the fuel-injection and intake-air amounts are less than the fuel-injection and intake-air variation thresholds, respectively.

A method for propulsion of a vehicle (100) having a combustion engine (101) and a gearbox (103), the engine (101) having a combustion chamber with an inlet for supply of combustion gas and an outlet for evacuation of exhaust gas, the method includes, during a change of gear from a first higher to a second lower gear ratio, increasing the pressure (P.sub.ut) at the chamber outlet (202) with a turbocharger unit and, when the rate of revolution (n) of the combustion engine (101) has at least partially fallen, controlling the turbocharger unit (203) such that the combustion gas pressure (P.sub.in) is increased.

A method for propulsion of a vehicle (100): The vehicle (100) includes a combustion engine (101), and a gearbox (103) that can be adjusted to a number of gear ratios for transfer of force between the combustion engine (101) and at least one driving wheel (113, 114), at least one combustion chamber with at least one inlet for the supply of combustion gas and at least one outlet for the evacuation of an exhaust gas flow that has resulted from combustion in the combustion chambers and a turbocharger unit (203) for pressurizing the combustion gas. In the method, during the change of gear from a first higher gear ratio to a second lower gear ratio, the rate of revolution of the combustion engine (101) is reduced, to control the turbocharger unit such that the pressure of the combustion gas is reduced, to increase the pressure at the outlet by constriction of the exhaust gas flow, and when the rate of revolution of the combustion engine (101) has at least partially fallen towards a second rate of revolution, to control the turbocharger unit such that the combustion gas pressure is increased. Also a system and a vehicle including the system.

A method for propulsion of a vehicle (100): The vehicle (100) includes a combustion engine (101), and a gearbox (103) that can be adjusted to a number of gear ratios for transfer of force between the combustion engine (101) and at least one driving wheel (113, 114), at least one combustion chamber with at least one inlet for the supply of combustion gas and at least one outlet for the evacuation of an exhaust gas flow that has resulted from combustion in the combustion chambers and a turbocharger unit (203) for pressurizing the combustion gas. In the method, during the change of gear from a first higher gear ratio to a second lower gear ratio, the rate of revolution of the combustion engine (101) is reduced, to control the turbocharger unit such that the pressure of the combustion gas is reduced, to increase the pressure at the outlet by constriction of the exhaust gas flow, and when the rate of revolution of the combustion engine (101) has at least partially fallen towards a second rate of revolution, to control the turbocharger unit such that the combustion gas pressure is increased. Also a system and a vehicle including the system.

Methods, systems, and computer program products are provided for controlling an internal combustion that comprises a cylinder having a space arranged to receive air and fuel, a piston disposed in the cylinder, and a crankcase being in fluid communication with the cylinder. The method comprises determining an uncontrolled behavior due to fluid flow between said crankcase and said cylinder space and combustion of such fluid, which entails: determining whether a powertrain of the vehicle is disengaged; determining whether the engine speed is increasing; and determining whether said cylinder space is receiving fuel. The method further comprises determining that an uncontrolled behavior is occurring if the conditions that: said powertrain is disengaged, the engine speed is increasing and said cylinder space is not receiving any fuel, are fulfilled.

Methods, systems, and computer program products are provided for controlling an internal combustion that comprises a cylinder having a space arranged to receive air and fuel, a piston disposed in the cylinder, and a crankcase being in fluid communication with the cylinder. The method comprises determining an uncontrolled behavior due to fluid flow between said crankcase and said cylinder space and combustion of such fluid, which entails: determining whether a powertrain of the vehicle is disengaged; determining whether the engine speed is increasing; and determining whether said cylinder space is receiving fuel. The method further comprises determining that an uncontrolled behavior is occurring if the conditions that: said powertrain is disengaged, the engine speed is increasing and said cylinder space is not receiving any fuel, are fulfilled.