Intake holes at the opposite ends are opened and closed by first intake valves. The middle intake hole is opened and closed by a second intake valve. A control device includes an intake variable valve device. First branch channels are connected to the intake holes and produce a normal tumble flow. A second branch channel is configured such that the flow rate of intake air passing through the middle intake hole is relatively greater on the side closer to the outer periphery of the combustion chamber. Where increasing the flow coefficient is given a higher priority, a three-valve drive mode is selected. Where the strength of the normal tumble flow is enhanced, a two-valve drive mode is selected. Where production of the normal tumble flow is reduced, a one-valve drive mode is selected.

In an internal combustion engine provided with an electro-hydraulic system for variable actuation of the intake valves of the engine, each cylinder has two intake valves, which are associated with two intake conduits and are controlled by a single cam of a camshaft through a single hydraulic circuit. The communication of the hydraulic actuators of the two intake valves with a discharge channel is controlled by two electrically-actuated control valves, both of an on/off two-position type, arranged in series with each other along a hydraulic line for communication between the a pressure volume and the discharge channel.

An engine includes: a duration apparatus for adjusting an opening duration of an intake valve, a Cylinder De-Activation (CDA) apparatus for controlling deactivation of an exhaust valve, an igniter, an injector for injecting a fuel, an operation state signal unit for measuring an operation state of a vehicle, and a controller for controlling the operations of the duration apparatus, the CDA apparatus, the igniter, and the injector based on an output signal from the operation state signal unit. A control method for this engine includes: determining, by the controller, whether the operation state of the vehicle corresponds to a CDA operation mode; and when the CDA operation mode is determined, operating the CDA apparatus so as to stop the operations of the igniter and the injector, increase an opening duration of the intake valve, and deactivate the exhaust valve by controlling the CDA apparatus.

An internal combustion engine is provided with a plurality of cylinders, air intake valves provided to each of the cylinders, and a variable valve actuation mechanism for varying the valve actuation of the air intake valves. A motor drives the variable valve actuation mechanism. A motor controller controls the motor. The internal combustion engine is capable of operating in a cylinder deactivation mode, in which the air intake valves of some of the cylinders are kept shut. When the internal combustion engine is reactivated from the cylinder deactivation mode, the motor controller executes an air intake amount correction process, in which the opening duration of the air intake valves is temporarily increased, thereby increasing the amount of air taken in by operating cylinder for which the air intake valves have been opened or closed even during the cylinder deactivation mode.

Aspects of the present invention relate to a control advanced system for controlling a valve actuator for an internal combustion engine, the control system comprising one or more controllers, the control system being configured to: receive a requirement signal retarded indicative of a requirement for valve actuation with a first valve timing characteristic; receive an expected flow signal indicative of expected mass flow rate of air, associated with the first valve timing characteristic; control the valve actuator to provide the first valve timing characteristic; receive an actual flow signal indicative of actual mass flow rate of air, associated with the control of the valve actuator; cause comparison of the actual flow signal with the expected flow signal; and cause an action to be performed in dependence on the comparison, wherein the action comprises a compensation action and/or a fault reporting action and/or determining camshaft phase information.

A valve rocker arm assembly, a variable air distribution mechanism, and an engine are provided according to the present disclosure. The valve rocker arm assembly includes: an oil inlet hose; a rocker arm shaft, an oil drain channel, an oil return groove, and a first oil path being provided in the rocker arm shaft, the oil drain channel being communicated with the oil return groove by means of the first oil path; a first rocker arm and a second rocker arm rotatably connected onto the rocker arm shaft, a piston cavity, an oil inlet path, an oil drain path and a piston being provided on the second rocker arm; a one-way opening device provided in the oil inlet path and/or the oil inlet hose; and a control valve connected to the oil drain channel.

A method for calculating the mass of an overlap gaseous flow (M.sub.OVL), wherein the exhaust pressure is higher than the intake pressure, or in the case of scavenging (SCAV), wherein the intake pressure is higher than the exhaust pressure. The overlap gaseous flow (M.sub.OVL) is the flow which flows, in overlap conditions, through the intake valve and the exhaust valve of a cylinder of an internal combustion engine. At least one intake valve is driven so as to vary the lift (H) of the intake valve in controlled manner. The overlap condition is a condition in which the intake valve and the exhaust valve are both at least partially open. The method comprises calculating the mass of the gaseous flow (M.sub.OVL) which flows through the intake valve and the exhaust valve on the basis of the relation:

M.sub.OVL=PERM*β(P/P.sub.0,n)*P.sub.0/P.sub.0_REF*(T.sub.0_REF/T.sub.0).sup.1/2/n.

A method for calculating the mass of an overlap gaseous flow (M.sub.OVL), wherein the exhaust pressure is higher than the intake pressure, or in the case of scavenging (SCAV), wherein the intake pressure is higher than the exhaust pressure. The overlap gaseous flow (M.sub.OVL) is the flow which flows, in overlap conditions, through the intake valve and the exhaust valve of a cylinder of an internal combustion engine. At least one intake valve is driven so as to vary the lift (H) of the intake valve in controlled manner. The overlap condition is a condition in which the intake valve and the exhaust valve are both at least partially open. The method comprises calculating the mass of the gaseous flow (M.sub.OVL) which flows through the intake valve and the exhaust valve on the basis of the relation:
M.sub.OVL=PERM*β(P/P.sub.0,n)*P.sub.0/P.sub.0_REF*(T.sub.0_REF/T.sub.0).sup.1/2/n.

A variable-lift valve train for a gas exchange valve of an internal combustion engine includes a lift adjuster, a lift actuator, and a lift lever. The lift adjuster has a working curve that is arrangeable at least in a first working position for setting a partial lift and in a second working position for setting a maximum lift. The working curve has a lift region and a base circle region. The lift actuator, which has an actuating contour configured to deflect the lift adjuster. The lift lever, which is deflectable via the working curve and thereby actuates a lift of the gas exchange valve. The valve train is configured to, in the first working position and in the second working position, actuate the gas exchange valve with an at least substantially equal maximum valve acceleration.

In an internal combustion engine provided with an electro-hydraulic system for variable actuation of the intake valves of the engine, each cylinder has two intake valves, which are associated with two intake conduits and are controlled by a single cam of a camshaft through a single hydraulic circuit. The communication of the hydraulic actuators of the two intake valves with a discharge channel is controlled by two electrically-actuated control valves, both of an on/off two-position type, arranged in series with each other along a hydraulic line for communication between the a pressure volume and the discharge channel.