An efficient engine combustion system with multiple combustion modes, includes a valve actuating mechanism, a pre-combustion chamber (30), and a main combustion chamber. The valve actuating mechanism is a fully variable valve mechanism; an intake valve (2) and an exhaust valve (26) are driven by high-pressure oil; ignition is implemented by means of an ignition apparatus of the pre-combustion chamber (30); and a spark plug (24) and a single-hole fuel injector (25) are mounted in the pre-combustion chamber (30), a bottom end of which is provided with a flame jet hole. The air inlet valve (2) and the exhaust valve (26) are respectively mounted thereon with an air inlet valve spring (4) and an exhaust valve spring (22); and the air inlet valve spring (4) and the exhaust valve spring (22) are separately connected to a hydraulic piston (21) that has an ejector rod; and the opening and closing of the air inlet valve (2) and the exhaust valve (26) are performed by the hydraulic piston (21). The efficient engine combustion system with multiple combustion modes may achieve smooth transition between different combustion modes, thus ensuring that the engine has optimal thermal efficiency under different operating condition regions.

Torque fluctuations caused by misfire and abnormal combustion are prevented appropriately at the time of switching from SI to HCCI, and exhaust of NOx is restricted at the time of switching. Provided is a control apparatus for an internal combustion engine performing a plurality of combustion modes each having a different air-fuel ratio and compression end temperature in a cylinder 7 from each other. In the middle of switching from a first combustion mode to a second combustion mode, an intermediate combustion mode in which the compression end temperature is increased while keeping a different air-fuel ratio from the air-fuel ratio of the first combustion mode and the air-fuel ratio of the second combustion mode is performed. Accordingly, at the time of switching between an operation mode performing SI and an operation mode performing HCCI, a temperature in the cylinder 7 and an air-fuel ratio are controlled appropriately, torque fluctuations caused by misfire and abnormal combustion can be prevented appropriately, and exhaust of NOx can be restricted.

Methods and systems are provided for protecting an exhaust catalyst from degradation during a DFSO event. Exit from DFSO due to pedal input received from an operator with a jittery foot is averted by filtering the pedal input differently when operating in a DFSO mode as compared to when operating out of the DFSO mode. Exit from DFSO is confirmed after receiving a higher than threshold pedal position input for a sustained period of time, or when an integrated fuel injection amount exceeds a threshold amount.

The present invention relates to a method for controlling lubrication of a connecting rod bearing of an internal combustion engine arrangement. The method comprises the steps of controlling an inlet valve to be maintained in the closed position during a movement of the reciprocating piston from the top dead center during an intake stroke for a predetermined number of crank angle degrees; and positioning the inlet valve in the open position when the reciprocating piston has traveled the predetermined number of crank angle degrees from the top dead center, wherein lubricating medium is provided to the connecting rod bearing within a predetermined time period before the inlet valve is arranged in the open position.

An object of the present invention is to predict change of a combustion limit due to cycle variation of temperature and an EGR ratio and perform correction every cycle to decrease an amount of combustion consumption. Therefore, in an internal combustion engine control device that controls an internal combustion engine including a cylinder and an exhaust pipe, the internal combustion engine control device includes a control unit configured to perform EGR control of controlling an exhaust gas in the exhaust pipe to return to an inner cylinder of the cylinder, obtain temperature of the gas in the internal cylinder and an EGR ratio in a state where both an intake valve and an exhaust valve are closed in an combustion cycle, and correct a combustion parameter in a same combustion cycle as the combustion cycle on the basis of the obtained gas temperature and the obtained EGR ratio.

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.

A system and method of controlling a cylinder deactivation mechanism can comprise executing a valve lift event configured to lift a valve via a rocker arm. The rocker arm can be configured with a controllable latch in a latched condition, wherein the controllable latch is configured with an edge that is clamped in a recess in the rocker arm during the valve lift event, a clamp force supplied in part by pressure from the valve lift event. A deactivation signal can be sent to select the unlatched condition to collapse the controllable latch from the recess while the controllable latch is configured in the valve lift event with the edge clamped in the recess. A subsequent valve lift event can have actuation deactivated by collapsing the controllable latch from the recess once the valve lift event is complete and the clamp force is removed.

A control system of a compression-ignition engine is provided, which includes an engine configured to cause combustion of a mixture gas inside the combustion chamber, an injector attached to the engine and configured to inject fuel into the combustion chamber, a spark plug disposed to be oriented into the combustion chamber and configured to ignite the mixture gas inside the combustion chamber, and a controller connected to the injector and the spark plug and configured to operate the engine by outputting a control signal to the injector and the spark plug, respectively. After the spark plug ignites the mixture gas to start combustion, unburned mixture gas combusts by self-ignition. The controller outputs the control signal to the injector so that a fuel injection timing is advanced when the engine operates at a high speed than at a low speed.

When the geometric compression ratio of an engine body is set to 13:1 or more and the engine body operates in a preset high load region, the effective compression ratio of the engine body is set to 12:1 or more with a difference from the geometric compression ratio being within 2, a gas to be introduced into a combustion chamber is supercharged by a supercharging system, fuel is injected at least in a compression stroke by an injector, and after the fuel injection is finished, an air-fuel mixture in the combustion chamber is ignited by an ignition device before the compression top dead center and is thus burned by flame propagation in the engine body, and then the unburned air-fuel mixture is burned by compression ignition.

The internal combustion engine includes: a plurality of cylinders each including a piston that reciprocally operates in association with rotation of a crankshaft, and an intake valve and an exhaust valve that open and close a combustion chamber; a starter motor that drives and rotates the crankshaft; and a valve opening-closing timing control mechanism that sets opening and closing timings of the exhaust valve by driving an electric actuator. If an environmental temperature detected by an environmental temperature sensor is less than 10 degrees below freezing, the control device controls the electric actuator such that the closing timing of the exhaust valve is made different from a top dead center of the piston, at a point in time when cranking is performed, and an initial combustion in one of the plurality of cylinders that is set to be the cylinder in which combustion is performed first is performed.