A control system of a compression-ignition engine includes an intake variable mechanism and a controller. In a second operating range, the controller controls the intake variable mechanism so that, while partial compression-ignition combustion is performed under an air-fuel ratio (A/F) lean environment, an intake valve open timing takes timing at an advanced side of an exhaust TDC. In a first operating range on a lower load side, the controller controls the intake variable mechanism so that, while the partial compression-ignition combustion is performed under the A/F lean environment, under the same engine speed condition, the intake valve close timing is more retarded within a range on a retarded side of an intake BDC as the engine load decreases, and an absolute value of a change rate of the intake valve close timing to the engine load becomes larger than in the second range.

Assume that a boundary on the air-fuel ration operation is changed from a boundary (i) to a boundary (ii). Then, after the boundary is changed, a high EGR operation region where a target EGR rate is set to a high value overlaps partially with a rich operation region. Therefore, when it is determined that the current operating point exists in the overlapped region, the target EGR rate is forcibly lowered. In addition, the boundary on a drive cam for an intake valve is changed from a boundary (I) to a boundary (II) thereby a region where a small cam is selected is enlarged.

Systems and related methods include a rocker arm having integrated components, including a lost motion actuator piston and components for resetting the lost motion actuator piston to provide normal valve closing or late valve closing. Selective reset is facilitated by a reset piston and a blocking piston disposed in a hydraulic circuit including a reset passage. In a non-resetting mode of operation, the blocking piston may block oil flow within the reset passage, regardless of the position of the reset piston, which facilitates late valve closing. An alternative embodiment includes a blocking sleeve disposed concentrically relative to the reset piston.

An abnormality diagnosis system of an internal combustion engine that is installed on a vehicle and includes an actuator includes an electronic control unit. The electronic control unit receives vehicle outside information concerning a period of time for which the vehicle speed is less than a predetermined value, and determines whether the period for which the vehicle speed is less than the predetermined value is expected to be equal to or longer than a length of time required for an abnormality diagnosis of an abnormality diagnosis target device. The electronic control unit activates the actuator and starts the abnormality diagnosis as the vehicle speed becomes lower than the predetermined value, when it determines that the period for which the vehicle speed is lower than the predetermined value is expected to be equal to or longer than the time required for the abnormality diagnosis of the target device.

An RF electronic impedance tuner uses multiple PIN diodes, Varactors or MOSFETs, mounted in a low loss slab-line, between the bottom surface of the center conductor and ground, are DC controlled individually and spaced appropriately along the slab-line in order to generate maximum Gamma and bandwidth. The electronic tuner is combined with a slide screw tuner, using the same slab-line in various configurations, before, after or sharing the same slab-line section, mounted on top of each-other. Calibration on a VNA allows high Gamma and harmonic tuning.

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.

A variable system of an internal combustion engine spaces a closing timing IVC of an intake valve apart from an intake bottom dead center BDC by a variable actuation valve mechanism and also increases a mechanical expansion ratio E by a variable compression ratio mechanism when an engine torque increases to around a maximum engine torque. The variable system sets the closing timing IVC of the intake valve to a closing timing IVCd spaced apart from the intake bottom dead center BDC around the maximum engine torque. Due to this control, the variable system can reduce an effective compression ratio to enhance a knocking resistance capability, and, further, achieve improvement of thermal efficiency and also reduce a temperature of exhaust gas to prevent or reduce thermal damage on an exhaust-system component by increasing the mechanical expansion ratio.

Provided is a control device for controlling an internal combustion engine including a fuel injection valve, an ignition device, and a variable valve operating device configured to switch between a base opening/closing mode of an intake valve and a continuous valve opening mode. The control device is configured to execute a cold start control at a cold start. The cold start control includes: a startability improvement processing executed in a predetermined number of cycles after the start of cranking; and a combustion start processing executed after this predetermined number of cycles. In the startability improvement processing, the continuous valve opening mode is selected in at least an expansion stroke and an exhaust stroke, and fuel injection is executed without ignition. In the combustion start processing, the base opening/closing mode is selected continuously during one cycle, and ignition is executed.

A method is provided for monitoring the operation of intake valves of an internal combustion engine, where at least one or more cylinders of the engine have more than one intake valve, and adapted to operate in different modes where at least one of the intake valves for a particular cylinder can be selectively activated, or deactivated so as not to open during a firing sequence for the cylinder. The method includes a) monitoring the intake manifold air pressure; b) during a time window with respect to the intake phase for said respective cylinder, determining the condition of whether the manifold pressure drops by a threshold or to a particular threshold level; and c) determining the functionality of the intake valves dependent on the outcome of step b).

An internal combustion engine includes a cylinder block that defines a cylinder and a cylinder head mounted to the cylinder block. A reciprocating piston is arranged inside the cylinder for compressing an air and fuel mixture at a geometric compression ratio of at least 10:1. A crankshaft is arranged in the cylinder block and rotated by the piston. An intake valve is operatively connected to the cylinder head and controls delivery of air to the cylinder for combustion therein. A mechanism provides a constant peak lift of the intake valve over an angle of rotation of the crankshaft that is at least 5 degrees, i.e., an extended dwell at peak lift. A multi-stage boosting system having first and second gas compressors is selectively controlled to pressurize air that is received from the ambient for delivery to the cylinder. A vehicle having such an engine is also disclosed.