A variable control method of exhaust temperature increase includes, when a cam phaser, which is connected to a double cam shaft having a coaxial arrangement structure of an outer shaft and an inner shaft, is operated and when a cam angle is determined as being varied by a controller, a cam phaser position change control is performed of decreasing a flow rate of an internal exhaust gas recirculation (EGR) supplied to a cylinder of an engine with a cam advance angle, increasing the flow rate of the EGR with a cam retard angle, or blocking the flow rate of the EGR with a maximal cam advance angle.

A control system for internal combustion engines having four valves per cylinder. An inlet valve and an exhaust valve are controlled by a basic camshaft. Another inlet valve and another exhaust valve are controlled by a control camshaft. The two camshafts are connected to a crankshaft and engine torque is managed by an electronic control unit. The system comprises a motor/generator unit, connected to the control camshaft; a differential, connected to the crankshaft and to the control camshaft; a control shaft, connected to the differential; an actuator, connected to the control shaft; a one-way restrictor valve connected to a shut-off valve and to the actuator; an oil circuit, connected to the actuator by means of the shut-off valve and a control solenoid that acts on the shut-off valve.

Methods and systems are provided for providing exhaust gas recirculation to a naturally aspirated internal combustion engine. In one example, exhaust gas is recirculated to an engine intake via a dedicated scavenging manifold and a scavenging exhaust valve. The exhaust gas and fresh air that has not participated in combustion may be recirculated to engine cylinders even at high engine loads since the exhaust gas and fresh air is returned to the engine air intake at a pressure greater than atmospheric pressure.

A four-stroke internal combustion engine is disclosed comprising an exhaust valve control arrangement with an exhaust valve phase-shifting device configured to phase-shift control of the at least one exhaust valve to a state where the at least one exhaust valve is controlled in such a way that it is opened during the expansion stroke of the engine and closed during the exhaust stroke of the engine, in order to achieve engine-braking via compression in the cylinders during the exhaust stroke. An inlet valve control arrangement comprises an inlet valve phase-shifting device configured to regulate the amount of air pumped through the engine during the engine braking by regulating the phase-shift of the at least one inlet valve. The present disclosure also relates to a vehicle comprising an engine and method of controlling an engine, a computer program and a computer program for performing a method of controlling an engine.

A system for actuating one or more engine valves for positive power operation and engine braking operation is disclosed. In a preferred embodiment, an exhaust valve bridge and intake valve bridge each receive valve actuations from two sets of rocker arms. Each valve bridge includes a sliding pin for actuating a single engine valve and an outer plunger disposed in the center of the valve bridge to actuate two engine valves through the bridge. The outer plunger of each valve bridge may be selectively locked to its valve bridge to provide positive power valve actuation. During engine braking, application of hydraulic pressure to the outer plungers may cause the respective valve bridges and outer plungers to unlock so that all engine braking valve actuations are provided from a rocker arm acting on one engine valve through the sliding pin.

A fuel injection control system may include a variable exhaust valve mechanism configured to primarily open an exhaust valve directly before an intake stroke in which an intake valve is opened and to secondarily open the exhaust valve during the intake stroke such that valve overlap occurs; an exhaust injector provided at an exhaust side to inject fuel; and a controller for controlling the exhaust injector such that fuel is injected through the exhaust injector before the exhaust valve is opened secondarily before or during the intake stroke.

A control device for engine comprising; a variable valve operating mechanism (72) which comprises a cam (72d) and a pressure chamber (72c) internally filled with engine oil; and a hydraulic valve (72b) associated with the pressure chamber (72c) and configured to be opened and closed to control the oil pressure to be applied to an intake valve (22). When the engine load falls within a given low engine load range, the valve opening timing of the intake valve (22) is increasingly retarded according to the engine load and as the engine load becomes higher, within a limit of a given timing, and, when the engine load is increased beyond the given low engine load range, the valve opening timing of the intake valve is fixed to the given timing.

A method for operating a reciprocating internal combustion engine in an engine braking mode of operation is provided. The method includes closing, for a first time, at least one exhaust valve of at least one cylinder in the engine braking mode of operation within a working cycle, and opening for a first time, and closing, for a second time, the at least one exhaust valve of the at least one cylinder, and opening for a second time to thereby discharge compressed gas in the cylinder via a piston of the cylinder from the cylinder. After the first opening and before the second closing, the exhaust valve is kept open, until the cylinder is filled with gas which flows through at least one exhaust channel from at least one second cylinder of the reciprocating internal combustion engine.

Methods, devices, controllers, and algorithms are described for operating an internal combustion engine wherein at least some firing opportunities utilize low temperature gasoline combustion (LTGC). Other firing opportunities may be skipped or utilize some other type of combustion, such as spark ignition. The nature of any particular firing opportunity is dynamically determined during engine operation, often on a firing opportunity by firing opportunity basis. Firings that utilize LTGC produce little, if any, nitrous oxides in the exhaust stream and thus, in some implementations, may require no aftertreatment system to remove them from the exhaust stream.

An electronic control unit of an internal combustion engine is configured to control the fuel injection valve and to control a spark plug if necessary such that fuel is combusted by pre-mixture compression ignition combustion or flame propagation combustion. The electronic control unit is configured to perform homogeneous combustion in a flame ignition operation range when switching failure has not occurred, the homogeneous combustion being combustion in which fuel homogeneously diffused into the combustion chamber is ignited using the spark plug and is combusted by flame propagation combustion. The electronic control unit is configured to perform spray-guided stratified combustion in a second operation range when the switching failure has occurred, the spray-guided stratified combustion being combustion in which fuel in the fuel injection path is ignited using the spark plug and is combusted by the flame propagation combustion.