Abstract: Internal combustion engine and method for buffering of combustion gases and fresh air in a storage tank and producing power, torque and other functions by consuming buffered gases from storage tank for improved efficiency, improved power and torque, reduced emissions, immediate response to increase or decrease power and torque requests, new and improved functionality, kinetic energy recovery, thermal energy recovery and increased ECM flexibility.

Abstract: A valve train of an internal combustion engine of a motor vehicle includes a rocker arm assigned to a first combustion chamber of the internal combustion engine where via the rocker arm a gas exchange valve assigned to the first combustion chamber is actuatable. An actuating device is assigned to a second combustion chamber of the internal combustion engine where via the actuating device, by supplying the actuating device with a hydraulic fluid, the second combustion chamber is switchable between a firing mode for fired operation and a braking mode for an engine braking operation of the internal combustion engine. A supply of the hydraulic fluid to the actuating device assigned to the second combustion chamber is adjustable by the rocker arm assigned to the first combustion chamber.

Abstract: Systems for valve actuation in internal combustion engines provide configurations for hydraulic lash adjusters and valve actuation valvetrain components that are particularly suitable for prevention of HLA jacking in dedicated cam environments including Type II valvetrain architectures. In one implementation, a lash adjuster loading component, which may comprise a stroke-limited spring biased piston associated with the main event valvetrain keeps the lash adjuster under a constant compressive force to prevent jacking.

Abstract: Methods and systems are provided for a hydrogen combustion engine. In one example, a method may include operating the hydrogen combustion engine at one of two combustion air ratios, wherein a combustion air ratio between the two is avoided via adjusting one or more operating parameters.

Abstract: The present invention relates to a method for increased exhaust gas temperature and emission reduction at partial loads in a diesel engine, wherein said engine comprises a cylinder with a reciprocating piston, a variable compression volume (VCR), and at least one exhaust valve and at least one inlet valve, the latter being equipped with variable valve timing (WT). According to the prevailing engine power requirement, an engine control system determines when to open and close said inlet valve, and the size of said compression volume in order to achieve a sufficiently elevated exhaust gas temperature so that correct exhaust gas purification can be achieved.

Abstract: A method for controlling the temperature of re-circulated exhaust gas in an internal combustion engine includes operating the internal combustion engine on a base line mode, receiving a signal indicative of an engine operating temperature, wherein the engine operating temperature is one of coolant temperature, exhaust temperature and oil temperature, comparing the engine operating temperature to a predetermined IEGR threshold, when the engine operating temperature is less than the predetermined IEGR threshold, activating an IEGR mode and activating an EEVO mode, and when the engine operating temperature is greater than the first predetermined IEGR threshold, deactivating the IEGR mode and deactivating the EEVO mode.

Abstract: An internal combustion engine includes combustion chambers, each having a controllable intake valve controlling an intake port, a controllable exhaust valve controlling an exhaust port, a piston, and a fuel injector. An intake manifold is connected to the intake port of each chamber. In catalytic converter warm-up mode, each chamber is driven in four-stroke operation including a 720 crank angle degrees cycle, and opens the intake port, starting to open in 90-180 CAD, and fully closes the intake port in 180-270 CAD, opens the exhaust port during the power stroke, starting in 405-495 CAD, opens the intake port during the exhaust stroke, starting in 610-690 CAD, and fully closes the exhaust port during the exhaust stroke in 630-710 CAD. Exhaust gas is forced into the intake manifold by the piston, mixing fuel and exhaust in the intake manifold, and fully closes the intake port in 700 to 720+20 CAD.

Abstract: An engine control device is provided, which includes an engine body where a cylinder is formed, an exhaust passage through which exhaust gas discharged from the engine body circulates, a NOx sensor disposed in the exhaust passage and configured to detect a concentration of NOx in the exhaust gas, an injector configured to change an air-fuel ratio inside the cylinder, an in-cylinder temperature changer configured to change a temperature inside the cylinder, and a controller configured to control the injector and the exhaust shutter valve. The controller controls the injector based on a detection value of the NOx sensor to variably set the air-fuel ratio inside the cylinder, and when a particular condition that the air-fuel ratio inside the cylinder is leaner than a preset upper limit is satisfied, and causes the in-cylinder temperature changer to raise the temperature inside the cylinder.

Abstract: An internal combustion engine system includes an engine with a plurality of pistons housed in respective ones of a plurality of cylinders, an air intake system to provide air to the plurality of cylinders through respective ones of a plurality of intake valves, an exhaust system to release exhaust gas from the plurality of cylinders through respective one of a plurality of exhaust valves, an aftertreatment system to treat exhaust emission from the engine, and a controller coupled to at least one sensor and configured to control a variable valve actuation mechanism to provide variable engine braking for thermal management.

Abstract: Methods and systems are provided for adjusting an EGR valve operation based on results from an EGR valve diagnostic. In one example, a method may include executing the EGR valve diagnostic during an engine deactivation, wherein the EGR valve diagnostic estimates an EGR valve stickiness used to adjust the EGR valve operation.

Abstract: An internal EGR amount calculation device for an internal combustion engine, which is capable of properly and easily calculating an internal EGR amount according to the change in the valve timing and enhancing the calculation accuracy of the internal EGR amount. The device includes an ECU. The ECU calculates an amount of burned gases remaining in a cylinder when the valve timing is predetermined reference timing, as a reference internal EGR amount. The ECU calculates a change in the amount of burned gases flowing into or out of the cylinder with respect to the amount of burned gases flowing into or out of the cylinder when the valve timing is the predetermined reference timing, as an internal EGR increase/decrease amount. Then, the ECU calculates the internal EGR amount by adding the internal EGR increase/decrease amount to the reference internal EGR amount.

Abstract: Systems and methods for diagnosing operation of an internal exhaust gas recirculation system of an internal combustion engine are presented. The system and method may be applied to conventional or hybrid powertrains having a capability to rotate an engine via an electric machine. The internal exhaust gas recirculation system may be diagnosed based on output of a differential pressure sensor.

Abstract: A heat engine includes a system for varying the compression ratio of the engine. The compression ratio varying system comprises: at least one eccentric part rotatably mounted on a crank pin. The eccentric part has an eccentric outer face that co-operates with one end of a rod, as well as at least one ring gear. A device for controlling the angular position of the eccentric part, includes an actuating pinion mounted on an actuating shaft. The control device also comprises at least one stepped intermediate pinion having at least first and second steps each formed by a pinion, the pinion of the first step meshing with the actuating pinion and the pinion of the second step meshing with the gear of the eccentric part.

Abstract: An internal combustion engine includes an intake passage of the internal combustion engine, an exhaust passage of the internal combustion engine, and an EGR passage connecting the intake passage and the exhaust passage. The internal combustion engine further includes a throttle valve provided downstream of a connected part to the EGR passage in the intake passage, and configured to control an intake air quantity toward a downstream side of the connected part, and an intake throttle valve provided upstream of the connected part to the EGR passage in the intake passage. In a control device of the internal combustion engine, an opening degree of the intake throttle valve is determined on the basis of an opening degree of the throttle valve.

Abstract: A fuel injection amount control device controls a fuel injection amount of an injector in an internal combustion engine including a blow-by gas ventilation system. The fuel injection amount control device includes a reflection rate setting section, a dilution correction section, and a dilution learning section. The reflection rate setting section sets a reflection rate proportional to the amount of a blow-by gas discharged to an intake air. The dilution correction section corrects a fuel injection amount by using, as a correction value, the product obtained by multiplying a reflection rate by a dilution learning value. The dilution learning section updates the dilution learning value such that an air-fuel ratio F/B correction value approaches 0 on the condition that a fuel dilution amount of engine oil is equal to or greater than a predetermined value.

Abstract: A scavenged gas amount calculation device for an internal combustion engine, which is capable of accurately calculating a scavenged gas amount under conditions where scavenged gases are produced during a valve overlap time period, and an internal EGR amount calculation device for the engine, which is capable of calculating an internal EGR amount using the scavenged gas amount thus calculated. The internal EGR amount calculation device includes an ECU. The ECU calculates a basic blown-back gas amount using an average intake pressure, a maximum exhaust pressure, and a correction coefficient (step 6), calculates a scavenged gas amount using the average intake pressure, a minimum exhaust pressure, and a scavenge ratio (step 8), calculates a blown-back gas amount by correcting the basic blown-back gas amount by the scavenged gas amount (step 11), and calculates the internal EGR amount according to the blown-back gas amount (step 12).

Abstract: An internal EGR amount calculation device for an internal combustion engine, which, even when a timing position relationship between a valve overlap period and an exhaust top dead center has changed, can properly calculate an internal EGR amount according to the change and can improve a calculation accuracy of the internal EGR amount. The internal EGR amount calculation device for an internal combustion engine includes an ECU. The ECU calculates a basic blow back gas amount, calculates a crank angle position in the center between the starting point and the ending point of the valve overlap period as an overlap center position, calculates a blow back gas amount by correcting the basic blow back gas amount according to the overlap center position, and calculates the internal EGR amount, using the calculated blow back gas amount.

Abstract: The invention relates to a method for monitoring at least one exhaust gas turbocharger (ATL) of a large internal combustion engine (BKM), comprising at least one compressor (1a) and one exhaust gas turbine (1b) arranged on the same shaft as the compressor, wherein the current pressures (p1, p2) upstream and downstream of the compressor (1a) and the current temperatures (T1, T4) upstream of the compressor (1a) and upstream of the exhaust gas turbine (1b) are measured.

Abstract: A vehicle EGR cooler may include a housing provided wherein coolant flows therein, a gas tube into which exhaust gas flows through the housing, cooling fins disposed in the gas tube, a variable valve, a portion of which is fixed to one side of the housing, the variable valve having a length varied in a width direction of the cooling fins depending on a temperature of a coolant, and an auxiliary cooling fin provided at one side of the housing to be connected to the variable valve, the auxiliary cooling fin being inserted into the gas tube to be formed between the cooling fins, the auxiliary cooling fin coming into contact with or being away from the cooling fins while moving according to a variation in length of the variable valve, varying a radiation area for the exhaust gas.

Abstract: A control device of a compression-ignition engine is provided. The device includes an engine having a cylinder, a fuel injection valve for injecting a fuel, an exhaust valve mechanism for switching an operation mode of an exhaust valve between a normal mode and an open-twice mode, a throttle valve disposed on an intake passage, and a controller for operating the engine by compression-ignition combustion of mixture gas inside the cylinder at least within a low engine load range. The controller suspends the fuel injection by the fuel injection valve when a predetermined fuel cut condition is met while the engine decelerates, and the controller fully closes the throttle valve and controls the exhaust valve mechanism to operate in the open-twice mode during the fuel cut. When a predetermined fuel resuming condition is met, the controller restarts the fuel injection, opens the throttle valve, and causes the compression-ignition combustion.

Abstract: An internal combustion engine is configured to operate in a homogeneous-charge compression-ignition combustion mode and a spark-ignition combustion mode employing late intake valve closing. A method for operating the internal combustion engine includes determining an amount of residual gas re-inducted into a combustion chamber from a previous engine cycle and determining an amount of fresh air trapped in the combustion chamber for the present engine cycle based upon the amount of residual gas re-inducted into the combustion chamber from the previous engine cycle. Engine fueling to the cylinder for the present engine cycle is controlled based upon the amount of fresh air trapped in the combustion chamber for the present engine cycle.

Abstract: Provided is a control device for an internal combustion engine, which is capable of suppressing occurrence of knocking due to pre-ignition and occurrence of misfire even when an operating state in a previous cycle changes in a subsequent cycle. When a ratio of change in heat of air-fuel mixture, which is an index indicating how a heat of air-fuel mixture in the previous cycle changes in the subsequent cycle, does not fall within an allowable range, a variable valve control mechanism capable of changing a valve-closing timing of an exhaust valve for adjusting an internal EGR gas amount is controlled by using an optimum value of exhaust valve close (EVC) timing derived by correcting a set valve-closing timing of the exhaust valve so that the ratio of change in heat of air-fuel mixture falls within the allowable range.

Abstract: An engine control system coordinates control of a pressure regulating mechanism associated with a turbocharger turbine and control of a variable valve actuating (VVA) mechanism for expanding the range of possible exhaust gas recirculation rates over a large portion of an engine operating map to provide EGR rates which are greater than typical present-day levels while mitigating engine pumping losses by causing the turbocharger to operate with better efficiency in some regions of the map where it otherwise would not. Turbocharger efficiency is improved by controlling the VVA mechanism to set the timing of operation of its respective cylinder valves in accordance with a predetermined correlation of operating efficiencies of a compressor to timing of operation of respective engine cylinder valves, causing the compressor to operate at points of better efficiency than it otherwise would without use of VVA.

Abstract: Provided is a control apparatus for a supercharged internal combustion engine. A turbo supercharger, an exhaust bypass passage, a WGV capable of switching the opening and closing of the exhaust bypass passage, and variable valve operating mechanisms capable of changing a valve overlap period are included. The valve overlap period is shortened so that the fresh air blow-through amount Gsca becomes equal to or smaller than a predetermined blow-through determination value Gjudge when the blow-through amount Gsca is larger than the blow-through determination value Gjudge. The WGV is opened when the blow-through amount Gsca is still larger than the blow-through determination value Gjudge after the valve overlap period has been shortened.

Abstract: Provided is a control device for a multi-cylinder internal combustion engine, including: a supercharger to be driven by exhaust gas energy; and a fuel injection control unit, in which the fuel injection control unit sets a fuel injection amount for one cylinder so that an air/fuel ratio in the one cylinder is richer than a theoretical air/fuel ratio, and exhaust gas exhausted when the one cylinder is in an exhaust stroke and scavenging gas scavenged during a valve overlap period from another cylinder which is in an intake stroke when the one cylinder is in the exhaust stroke are mixed in an exhaust pipe so as to attain an air/fuel ratio facilitating combustion.

Abstract: Methods and systems are described for controlling engine combustion during a mixed-mode combustion modality. A target exhaust valve timing is determined based on a first combination of engine speed and load. An amount of trapped residual in an engine cylinder after an exhaust valve is closed during a first combustion cycle is also determined. Based at least in part on the amount of trapped residual, an amount of gas that will be drawn into the engine cylinder when the intake valve is opened during a second combustion cycle is determined. The target exhaust valve timing is then adjusted during the second combustion cycle in order to adjust the amount of gas that will be drawn into the engine cylinder when the intake valve is opened during a third combustion cycle.

Abstract: A cylinder valve system in an engine is provided. The cylinder valve system includes a first oil pressurized bore corresponding to a cylinder valve and in fluidic communication with a control valve assembly, the control valve assembly comprising at least one hydraulic valve and a second oil pressurized bore corresponding to the cylinder valve and in fluidic communication with the control valve assembly.

Abstract: A method of controlling combustion of an engine improves unstable ignition and knocking which may be generated in an engine to which a diesel-gasoline mixed combustion mode and a gasoline mixed combustion mode are applied to low load and high load driving zones. The method includes: determining a combustion mode according to a current driving state of the engine; determining a compression ratio corresponding to the combustion mode; controlling a variable compression ratio device to control a compression ratio of a cylinder; determining whether the combustion state of the engine obtained during the combustion after the control to the compression ratio satisfies a set condition; and performing a compression ratio compensation such that the combustion state of the engine satisfies the set condition with taking a combustion pressure sensor signal as a feedback signal when the set condition is not satisfied.

Abstract: Various methods for compensating a deflected linkage in a wastegate arrangement are provided. In one example, current is applied to an actuator to move a wastegate valve coupled through a linkage to the actuator for diverting gasses from a turbocharger. The position of the actuator is indicated, and a correction to said indicated actuator position is applied compensating for deflection of the linkage based at least on said applied current. Said applied current is adjusted when said corrected actuator position reaches a position corresponding to a desired valve position.

Abstract: A control system (12) for an engine (10) having a combustion chamber (22) is disclosed. The control system may have a fuel injector (40) configured to selectively inject fuel into the combustion chamber, and a controller (54) in communication with the fuel injector. The controller may be configured to activate the fuel injector during a first compression stroke to initiate fuel injection in an amount and at a timing that results in a stratified lean air/fuel mixture within the combustion chamber during a first combustion event of a six-stroke cycle. The controller may also be configured to activate the fuel injector during a first power stroke to initiate fuel injection in an amount and at a timing that results in a homogenous lean air/fuel mixture within the combustion chamber during a second combustion event of the same six-stroke cycle.

Abstract: An apparatus for actuating first and second engine valves comprises a rocker arm that receives motion from primary and auxiliary valve actuation motion sources at a motion receiving end of the rocker arm. A master piston residing in a master piston bore in the rocker arm is configured to received motion from the auxiliary valve actuation motion source. A slave piston residing in a slave piston bore in the rocker arm is configured to provide auxiliary valve actuation motion to the first engine valve. A hydraulic circuit is provided in the rocker arm connecting the master piston bore and the slave piston bore, and a check valve is disposed within the rocker arm, configured to supply hydraulic fluid to the hydraulic circuit. The apparatus may be incorporated into a system comprising a rocker arm shaft and the primary and secondary valve actuation motion sources, such as an internal combustion engine.

Abstract: When a blow-by gas collides with an outer circumferential wall of a tubular member, part of oil mist in the collision gas is liquefied (an oil droplet). The oil droplet takes in the oil mist in the blow-by gas which flows into an intake pipe in succession, and moves on the outer circumferential wall of the tubular member in accordance with a flow of an intake gas and the gravity while keeping a liquefied state. The oil droplet flows in from an inlet section while keeping the liquefied state, and uniformly flows into a surface of an impeller to be discharged to a scroll side. A surface of a diffuser is washed uniformly by the oil droplet keeping the liquefied state, and generation or accumulation of the deposit on the surface can be restrained.

Abstract: A method for controlling re-circulation of exhaust gas (EGR) in an internal combustion engine includes receiving a signal indicative of an engine operating temperature and comparing the engine operating temperature to a first predetermined IEGR threshold. When the engine operating temperature is less than the first predetermined internal EGR threshold, a first internal EGR mode is activated, whereby engine emissions may be reduced or combustion stability may be enhanced. When the engine operating temperature is greater than the first predetermined internal EGR threshold, the first internal EGR mode is deactivated, and a second internal EGR mode is activated, whereby emissions may be reduced as exhaust system heating is accelerated. When the operating temperature is greater than the second temperature threshold, the second internal EGR mode may be deactivated a third mode may be enabled with only external EGR.

Abstract: Methods and systems are provided for reducing EGR estimation errors during lean engine operating conditions. During lean engine operation, EGR is disabled if the estimated exhaust air-fuel ratio becomes leaner than a lean threshold. The lean threshold is adjusted based on an upper limit of EGR errors that may be tolerated by the engine at a given engine speed and load.

Abstract: A process is provided for improving combustion control and fuel efficiency in rotary and reciprocating IC engines by enabling leaner combustion at higher compression ratios using less heat for ignition. Embodiments employ secondary chambers of minimal total volume within a cylinder periphery. These chambers communicate with a main chamber via conduits and enable a radical ignition (“RI”) species generation and supply process that starts in earlier cycles to be augmented and used in later cycles. Measures regulate the RI species generated and provided to the main chamber. These species alter dominant chain-initiation reactions of the combustion ignition mechanism. Also employed when preferable are fluids of higher heat of vaporization and volatility but lower ignitability than the fuel. This process improves combustion in radical ignition engines and radical augmented spark and compression ignition engines.

Abstract: Methods are provided for controlling an engine. One method may include boosting engine intake air to a cylinder; and injecting an amount of a scavenging fluid into the cylinder based on an amount of cylinder residual exhaust gas. A scavenging fluid, such as water or windshield washer fluid evaporates on contact with the hot exhaust gases and hot metal components and the expanded volume of the vapor displaces the residual exhaust gas, thereby improving engine scavenging.

Abstract: In a method for operating a supercharged internal combustion engine of a motor vehicle, at the same time an internal exhaust gas recirculation and an external exhaust gas recirculation are carried out in an engine operating range with lean burn operation modes, wherein the exhaust gas recirculation rate of the internal and the external exhaust gas recirculation is increased with increasing load and/or speed of the internal combustion engine in the lean engine operating range and, at high engine speeds and loads, a homogenous mixture operation is carried out. The invention also reside in an internal combustion engine for performing the method.

Abstract: Energy to speed heating of a catalyst associated with an internal combustion engine can be provided in the form of sensible energy (heat) via hot combustion products. In some variations, timing of opening and/or closing of an exhaust valve can be manipulated to increase sensible heat delivered to the catalyst in the exhaust gases.

Abstract: Systems and methods for operating a turbocharged engine are described. In one example, a system comprises a cylinder head having a first and second exhaust duct separately coupled to first and second groups of cylinders, each of the first and second exhaust ducts leading to an exhaust driven turbine mounted inside the cylinder head on a bearing, the bearing located within a bearing housing supported by the cylinder head. In this way, exhaust pulses remain separate up to the turbine mounted inside the cylinder head.

Abstract: An internal combustion engine system includes: an engine with a plurality of pistons housed in respective ones of a plurality of cylinders; an air intake system to provide air to the plurality of cylinders through respective ones of a plurality of intake valves; an exhaust system to release exhaust gas from the plurality of cylinders through respective one of a plurality of exhaust valves; an aftertreatment system to treat exhaust emission from the engine; at least one sensor to provide a sensor signal corresponding to an efficiency of the aftertreatment system; and a controller coupled to the at least one sensor and operable to regulate an internal exhaust gas recirculation operation in the cylinders when the aftertreatment system operates at less than a desired efficiency.

Abstract: A method and system for providing a suitable engine torque response during a transient condition is presented. In one example, when a desired inlet manifold pressure is greater than a throttle inlet pressure of a first throttle, a second throttle positioned upstream from the first throttle is opened to increase the throttle inlet pressure. The method may provide an appropriate torque response while minimizing impact on fuel economy.

Abstract: The disclosure provides a diesel engine, which includes an engine body mounted in a vehicle and having a cylinder to be supplied with fuel containing diesel fuel as its main component, a geometric compression ratio ? of the cylinder being set within a range of 12:1 to 15:1, and an EGR system for allowing a part of burned gas to exist inside of the engine body cylinder when the engine body is at least in a particular operating state where an engine load and an engine speed are relatively low. The EGR system includes an EGR passage at least partially formed inside the engine body, and having a predetermined or shorter passage, an EGR control valve provided in a course of the EGR passage and for adjusting a flow rate of the burned gas inside the EGR passage, and a controller for controlling an opening of the EGR control valve.

Abstract: A piston engine is operated to close an exhaust valve, close an intake valve, and inject ammonia into a cylinder at a start of a compression motion of a piston before substantial compression occurs. The ammonia may be injected into the cylinder as a liquid. The ammonia may be pressurized sufficiently to prevent boiling of the ammonia at a temperature of the engine. A mixture of ammonia and air may be compressed sufficiently to obtain compression ignition of the ammonia. An amount of air in the cylinder during compression may be limited to limit combustion temperatures to below the temperatures for formation of NOx. Air may be injected into the cylinder after ignition of the ammonia and during combustion. The exhaust valve may be closed at a time to trap a predetermined amount of exhaust gas in the cylinder.

Abstract: For reducing the NOx-emission of a large sized two stroke diesel engine having at least one combustion room (3), a reciprocating piston (4) and an exhaust opening (12) controlled by an exhaust valve (13) at each work cyclus a small volume of burnt gas is retained in the combustion room (3) and so added to the fresh air for the next combustion. For achieving this retention of burnt gas the underside of the valve disc (15) off the exhaust valve (13) is provided with a shallow concave face (17) building a basin-like collection room, whose depth is within a range of 2-10% of the outer diameter of the valve disc (15).

Abstract: Methods and systems are described for controlling engine combustion during a mixed-mode combustion modality. A target exhaust valve timing is determined based on a first combination of engine speed and load. An amount of trapped residual in an engine cylinder after an exhaust valve is closed during a first combustion cycle is also determined. Based at least in part on the amount of trapped residual, an amount of gas that will be drawn into the engine cylinder when the intake valve is opened during a second combustion cycle is determined. The target exhaust valve timing is then adjusted during the second combustion cycle in order to adjust the amount of gas that will be drawn into the engine cylinder when the intake valve is opened during a third combustion cycle.

Abstract: A control device for a hybrid vehicle causes the hybrid vehicle to travel in limp-home mode with motive power from an engine when either a motor or a battery for travel cannot be used. The engine incorporated in the hybrid vehicle includes an EGR device for recirculating part of exhaust gas to an intake system of the engine again. Even if an operation state of the engine satisfies a prescribed EGR permission condition for operating the EGR device, during the travel in limp-home mode with an abnormality detection flag being set to 1, the control device prohibits operation of the EGR device.

Abstract: This disclosure provides a method of controlling a diesel engine. The method includes adjusting an EGR ratio according to an engine load so that a cylinder O2 concentration decreases gradually to a predetermined load with an increase in the load of the engine, while the O2 concentration increases gradually above the predetermined load, operating the engine in a premix combustion mode where the fuel injection is terminated before a top dead center of a compression stroke in a low load operating range including the predetermined load where the O2 concentration is lowest and, after that, the fuel ignites and combusts, and operating in a diffusion combustion mode where the fuel injection is executed in parallel to the ignition and combustion of the fuel in an operating range where the load is higher than that of the operating range in the premix combustion mode and the O2 concentration is relatively high.

Abstract: A method for controlling re-circulation of exhaust gas (EGR) in an internal combustion engine includes receiving a signal indicative of an engine operating temperature and comparing the engine operating temperature to a first predetermined IEGR threshold. When the engine operating temperature is less than the first predetermined internal EGR threshold, a first internal EGR mode is activated, whereby engine emissions may be reduced or combustion stability may be enhanced. When the engine operating temperature is greater than the first predetermined internal EGR threshold, the first internal EGR mode is deactivated, and a second internal EGR mode is activated, whereby emissions may be reduced as exhaust system heating is accelerated. When the operating temperature is greater than the second temperature threshold, the second internal EGR mode may be deactivated a third mode may be enabled with only external EGR.

Abstract: To provide a control system for an internal combustion engine, which is capable of providing a stable intake air amount through reduction of pumping loss and blow-back of combustion gases by appropriately controlling the valve-opening timing of the intake valves, and thereby being capable of securing excellent drivability. In the control system 1, the valve-closing timing of the exhaust valve 9 is changed by an exhaust-side variable valve-operating mechanism 60, whereby the internal EGR amount is controlled, and the valve-opening timing of an intake valve 8 of an internal combustion engine 3 is changed by an intake-side variable valve-operating mechanism 40.

Abstract: A control system for a direct-injection four-stroke internal combustion engine having at least one cylinder, an intake passage supplying air to the cylinder, and an exhaust passage removing exhaust gas from the cylinder, the control system including a mass air flow meter configured to detect a mass air flow upstream of the cylinder and a control unit. The control unit is configured to detect an intake air density in the cylinder, calculate an in-cylinder trapped intake air amount based on a cylinder volume and the detected intake air density, and estimate a difference between the intake air amount detected by the mass air flow meter and the in-cylinder trapped intake air amount, the estimated difference being an estimated scavenging amount representing a fresh air blowby amount passing from the intake passage into the exhaust passage.