A supercharging device for an engine includes an electric supercharger which supercharges intake air, an intercooler which cools intake air discharged from the electric supercharger; and an intake manifold which is disposed substantially horizontally, and is configured to communicate between a downstream end of the intercooler in an intake air flow direction, and intake ports. The downstream end of the intercooler is located on a lower end of the intercooler. The downstream end of the intercooler is disposed substantially at the same height as an upstream end of the intake ports. The electric supercharger is disposed below the intercooler along a surface of the engine on an intake side where the intake ports are opened.

A supercharging device for an engine includes an electric supercharger which supercharges intake air, an intercooler which cools intake air discharged from the electric supercharger; and an intake manifold which is disposed substantially horizontally, and is configured to communicate between a downstream end of the intercooler in an intake air flow direction, and intake ports. The downstream end of the intercooler is located on a lower end of the intercooler. The downstream end of the intercooler is disposed substantially at the same height as an upstream end of the intake ports. The electric supercharger is disposed below the intercooler along a surface of the engine on an intake side where the intake ports are opened.

It is common for crankshafts of internal combustion engines to have main bearing journals provided between each of the conrod bearing journals. However, to reduce engine friction, the fewest main bearing journals that can be used while still meeting the design targets is preferred. A crankshaft for an in-line, four-cylinder engine, according to an embodiment of the disclosure, has three main bearing journals. Bridges, one each located between first and second conrod bearing journals and between third and fourth conrod bearing journals. The bridges have a cross-section with at least two concavities to improve the strength of the bridge compared to, for example, a cylindrical bridge, without greatly increasing the mass of material used in the bridge. Furthermore, a locus of a centroid of cross sections through the bridge are not coincident with an axis of rotation of the crankshaft, but instead is displaced toward the nearer conrod bearing journal.

It is common for crankshafts of internal combustion engines to have main bearing journals provided between each of the conrod bearing journals. However, to reduce engine friction, the fewest main bearing journals that can be used while still meeting the design targets is preferred. A crankshaft for an in-line, four-cylinder engine, according to an embodiment of the disclosure, has three main bearing journals. Bridges, one each located between first and second conrod bearing journals and between third and fourth conrod bearing journals. The bridges have a cross-section with at least two concavities to improve the strength of the bridge compared to, for example, a cylindrical bridge, without greatly increasing the mass of material used in the bridge. Furthermore, a locus of a centroid of cross sections through the bridge are not coincident with an axis of rotation of the crankshaft, but instead is displaced toward the nearer conrod bearing journal.

A control device for an internal-combustion engine includes circuitry. The circuitry is configured to calculate, in accordance with an operating state of the internal-combustion engine, a basic supercharging pressure of intake gas generated by a supercharger provided in the internal-combustion engine. The circuitry is configured to acquire a flow rate change state parameter that correlates with a change state of the flow rate of the intake gas controlled by a flow rate control mechanism provided in the internal-combustion engine. The circuitry is configured to calculate a correction value in accordance with the flow rate change state parameter. The circuitry is configured to calculate an estimated supercharging pressure of the intake gas by correcting the basic supercharging pressure with the correction value. The circuitry is configured to control operation of the internal-combustion engine using the estimated supercharging pressure.

A control device for an internal-combustion engine includes circuitry. The circuitry is configured to calculate, in accordance with an operating state of the internal-combustion engine, a basic supercharging pressure of intake gas generated by a supercharger provided in the internal-combustion engine. The circuitry is configured to acquire a flow rate change state parameter that correlates with a change state of the flow rate of the intake gas controlled by a flow rate control mechanism provided in the internal-combustion engine. The circuitry is configured to calculate a correction value in accordance with the flow rate change state parameter. The circuitry is configured to calculate an estimated supercharging pressure of the intake gas by correcting the basic supercharging pressure with the correction value. The circuitry is configured to control operation of the internal-combustion engine using the estimated supercharging pressure.

Internal combustion engine having cam actuated valves that can be controlled to facilitate the use of different air charge levels in different cylinders or sets of cylinders are described. In one aspect a first set of cylinders is operated in a skip fire manner in which the corresponding cylinders are deactivated during skipped working cycles. Cam actuated intake valves associated with a second set of cylinders are operated differently so that the air charge in the cylinders in the second set is different than the air charge in fired cylinders subject to the skip fire control. According to another aspect, an engine having cam actuated intake valves is operated in a dynamic firing level modulation mode. During the dynamic firing level modulation operation, the cam actuated intake valves are controlled in at least two different manners to such that different cylinder working cycles have different air charges.

Internal combustion engine having cam actuated valves that can be controlled to facilitate the use of different air charge levels in different cylinders or sets of cylinders are described. In one aspect a first set of cylinders is operated in a skip fire manner in which the corresponding cylinders are deactivated during skipped working cycles. Cam actuated intake valves associated with a second set of cylinders are operated differently so that the air charge in the cylinders in the second set is different than the air charge in fired cylinders subject to the skip fire control. According to another aspect, an engine having cam actuated intake valves is operated in a dynamic firing level modulation mode. During the dynamic firing level modulation operation, the cam actuated intake valves are controlled in at least two different manners to such that different cylinder working cycles have different air charges.

Embodiments for operating an engine having parallel turbochargers and two fluidically coupleable, separated intake manifolds is provided. In one example, a method includes responsive to a first condition, operating a first cylinder group of an engine, deactivating a second cylinder group of the engine, and blocking fluidic communication between a first intake manifold coupled to the first cylinder group and a second intake manifold coupled to the second cylinder group, and responsive to a second condition, activating the second cylinder group and establishing fluidic communication between the first and second intake manifolds.

Embodiments for operating an engine having parallel turbochargers and two fluidically coupleable, separated intake manifolds is provided. In one example, a method includes responsive to a first condition, operating a first cylinder group of an engine, deactivating a second cylinder group of the engine, and blocking fluidic communication between a first intake manifold coupled to the first cylinder group and a second intake manifold coupled to the second cylinder group, and responsive to a second condition, activating the second cylinder group and establishing fluidic communication between the first and second intake manifolds.