A product and method are disclosed for use with an engine including an intake passage providing combustion air to the engine. An exhaust passage may channel expelled combustion gases from the engine. A first compressor may be disposed in the intake passage, and a turbine may be disposed in the exhaust passage and may be coupled to the first compressor. The turbine may be arranged to rotate as a result of a flow of exhaust gases through the exhaust passage to drive the first compressor. A flow control device may be disposed in the intake passage upstream from the first compressor. An alternate passage may be provided having a first end opening to the intake passage upstream from the flow control device and having a second end opening to the intake passage downstream from the flow control device. A second compressor may be disposed in the alternate passage, with a drive unit adapted to drive the second compressor. The flow control device may be adapted to be closed to substantially prevent flow through the intake passage and to be open to impart swirl to a gas stream in the intake passage.

An engine control method includes: a first fuel supply step of supplying fuel into the combustion chamber using an injector when a spark plug makes flame in the combustion chamber so that an air-fuel mixture is generated at least around the spark plug, the air-fuel mixture having an air-fuel mass ratio A/F or a gas-fuel mass ratio G/F, in which gas includes air, higher than a stoichiometric air-fuel ratio; after the first fuel supply step, an ignition step of making the flame in the combustion chamber in the compression stroke using the spark plug; and after the ignition step, a second fuel supply step of supplying the fuel into the combustion chamber in the compression stroke using the injector to increase a fuel concentration of the air-fuel mixture in the combustion chamber.

A direct fuel injection internal combustion engine having an injector for directly injecting fuel into a combustion chamber thereof is provided. The engine is configured so that a tumble flow is generated in the combustion chamber. A fuel injection by the injector can be performed in a first injection mode and a second injection mode, the first injection mode being a mode in which the fuel injection is completed after the tumble flow is generated, and the second injection mode being a mode in which the fuel injection is completed before the tumble flow is generated. The fuel injection of the first injection mode is performed before completion of the warming-up of the engine, and the fuel injection of the second injection mode is performed after completion of the warming-up of the engine.

An engine system is provided, which includes an engine, a swirl control valve, and a controller. The engine includes a cylinder, a piston, and a fuel injection valve provided incliningly with respect to an axial direction of the piston and configured to directly inject fuel into the cylinder. The swirl control valve is provided inside an intake passage and generates a swirl flow inside the cylinder at least when the valve closes. When an engine load is below a given threshold, the controller controls the swirl control valve to close, and controls the fuel injection valve to inject fuel during an intake stroke. While the engine load is below the threshold, at a fixed engine speed, the controller controls to advance a fuel injection timing when the engine load is at a first load, compared with at a second load higher than the first load.

A motor response control method in a variable charge motion system in which a VCM motor is differentially controlled by a PWM duty regardless of back pressure of intake air in an intake manifold when a current engine rotation speed in revolutions per minute is less than a specific engine rotation speed in revolutions per minute in a VCM position learning state by a controller whereas the VCM motor is differentially controlled by the PWM duty based on the back pressure of intake air in the intake manifold when the current engine rotation speed in revolutions per minute is greater than the specific engine rotation speed in revolutions per minute.

An engine system is provided, which includes an engine, a swirl control valve, an EGR passage, an EGR gas adjusting mechanism, and a controller. The engine includes a cylinder, a piston, and a fuel injection valve. The swirl control valve is provided inside an intake passage and generates a swirl flow inside the cylinder when it closes. When an engine load is at or below a given threshold, the controller controls the swirl control valve to close. While the engine load is the threshold or below, the controller controls the EGR gas adjusting mechanism such that, at a fixed engine speed, an increase rate of an EGR gas amount with respect to an increase in the engine load is lower in a first load range than in a second load range, the first load range being on a higher load side of the second load range and including the threshold.

Systems and methods for operating an engine with deactivating and non-deactivating valves are presented. In one example, estimates of engine fuel consumption for operating the engine with a plurality of cylinder modes or patterns while a transmission is engaged in different gears are determined and are used as a basis for deactivating engine cylinders.

A learning method for controlling opening or closing of an intake/exhaust valve of a vehicle may include a state determining step determining whether a vehicle state satisfies a learning entry condition, a learning frequency determining step determining whether a learning frequency is less than a preset reference frequency after the vehicle starts, when the vehicle state satisfies the learning entry condition, a change learning step learning an area of an inflow passage of the intake/exhaust valve that is changed due to a deposition of impurities, when the learning frequency while driving is less than the preset reference frequency after the vehicle starts, and an escape condition determining step determining whether the vehicle state satisfies a learning escape condition, after the learning step.

An engine system capable of controlling an intake air flow includes a combustion chamber, an ignition plug, an intake air flow control valve, and a controller. The controller performs, in at least a part of an operating range, SPCCI combustion in which after jump-spark ignition combustion of a portion of a mixture gas inside the combustion chamber by a jump-spark ignition of the ignition plug, compression ignition combustion of the remaining mixture gas is carried out by a self-ignition. The controller strengthens, at least in a part of the operating range of SPCCI combustion, the intake air flow inside the combustion chamber by controlling the intake air flow control valve. The controller controls, in a middle-load range of the operating range where SPCCI combustion is performed, the intake air flow control valve so that the intake air flow becomes weaker than in a high-load range and a low-load range.

An engine system provided. The engine system includes a rotatable flow guide including a flow altering surface positioned upstream of an intake valve having a first side with a curved contour, the flow altering surface generating tumble and swirl flow patterns of intake airflow entering a cylinder through the intake valve in a plurality of active positions. The engine system further includes a flow guide actuator rotating the flow altering surface to alter the tumble and swirl flow patterns of the intake airflow.