Abstract: A secondary air supply system includes a supply passage, a valve, and a detecting unit. Secondary air is supplied to the upstream of a purification apparatus in an exhaust passage of an engine through the supply passage. The valve communicates and blocks the supply passage to be in open and close conditions. The detecting unit detects a detection object of secondary air in the upstream of the valve in the supply passage. A diagnosis apparatus for the secondary air supply system includes a diagnosis unit that obtains a detection result of the detecting unit in each of the open and close conditions of the valve for evaluating an abnormity of the secondary air supply system in accordance with the detection result. The diagnosis apparatus includes a reliability maintaining unit that determines the diagnosis operation of the diagnosis unit to be valid when the detecting operations in the open and close conditions are continuously performed.

Abstract: In an internal combustion engine having a compressor in its induction system which has a compressor wheel rotatably mounted in an intake duct combustion air compressor, whereby the combustion air is compressed to an increased boost pressure, and an auxiliary duct which opens into the compressor intake duct, an adjustable blocking element being arranged in the compressor intake duct upstream of the compressor wheel and an adjustable swirl device being arranged in an opening region of the auxiliary duct, and an NOx storage catalytic converter being disposed in the exhaust gas system, the blocking device and the swirl device are adjustable so as to generate an air fuel ratio with an excess of fuel, and, at the same time a propulsive swirl is applied to the compressor wheel when the blocking element is moved to a position in which air supply to the compressor intake duct is restricted.

Abstract: A fuel injection amount control device is used for an internal combustion engine. A secondary air supply device supplies secondary air into an exhaust passage of the internal combustion engine. Flow amount calculating circuitry calculates a secondary air flow amount. The secondary air flows into the exhaust passage. Target air fuel ratio setting circuitry sets a target air fuel ratio when secondary air is supplied. Fuel amount correcting circuitry corrects a fuel injection amount in accordance with a current value of the secondary air flow amount such that the air fuel ratio on a downstream side of an inlet of secondary air in the exhaust passage becomes the target air fuel ratio when secondary air is supplied. Target changing circuitry monitors increase and decrease in the secondary air flow amount. The target changing circuitry changes the target air fuel ratio to one of a rich side and a lean side in accordance with the increase and decrease in the secondary air flow amount.

Abstract: The invention concerns a procedure to determine the sulfur removal of a NOx storage catalytic converter in an exhaust gas aftertreatment system of an internal combustion engine, whereby conditions, in which a surplus of the reducing agent is generated in the internal combustion engine, are adjusted in the internal combustion engine for the sulfur removal, whereby a SOx removal amount is determined in a SOx removal calculation using a model from the reducing agent flow and from additional operating parameters of the internal combustion engine. In so doing, dynamic effects during the desulferization of the NOx storage catalytic converter can be better taken into account for the SOx removal calculation; and in so doing, the subsequent effect of the NOx storage catalytic converter on the reduction of the nitrogen oxides in the exhaust gas can be more accurately predicted, which makes the process management more streamlined and consequently more fuel efficient.

Abstract: A secondary air pipe is connected to an exhaust pipe upstream of a catalyst, and a secondary air pump is connected to an upstream portion of the secondary air pipe. An ECU determines an operating period of the secondary air pump before the secondary air pump is operated in order to drive the secondary air pump within the operating period. Especially, the ECU detects a pump driving load during a secondary air supply to correct the operating period of the secondary air pump based on the detected pump driving load.

Abstract: A secondary air control system supplies secondary air to the upstream of a catalyst purifying exhaust gas in an exhaust passage of an engine. A diagnostic device includes a secondary air detecting means that detects a secondary air information related to pressure of secondary air. An abnormality diagnostic means performs an abnormality diagnostic operation of the secondary air control system in accordance with the secondary air information. A voltage detecting means that detects a power source voltage information related to power source voltage supplied to the secondary air control system. An evaluating condition correcting means that corrects an evaluating condition, which is used for evaluating abnormality in the secondary air control system in accordance with a power source voltage information.

Abstract: Intake air is severely restricted during cold start of a diesel engine to provide high engine-out exhaust gas temperatures and quickly heat exhaust treatment devices. Cylinder pressures are maintained substantially below the pressure of the ambient atmosphere during a principal portion of the intake stroke of each combustion cycle to promote rapid fuel vaporization and higher combustion temperatures. The engine is operated in a premixed charge compression ignition combustion mode to provide a high engine-out exhaust temperature, stable combustion, and low emissions during the cold start period.

Abstract: There is provided a device for supplying secondary air, which comprises a secondary air passage for supplying secondary air, to an exhaust passage of an engine, upstream of an exhaust purification device provided in the exhaust passage, a pump provided in the secondary air passage for supplying a secondary air, a battery used for driving the pump, at least one opening-closing device for opening and closing the secondary air passage, and a pressure sensor provided between the pump and the opening-closing device for detecting a pressure in the secondary air passage. A malfunction of at least one of the pump and the opening-closing device is detected on the basis of at least one of the pressures detected when the secondary air passage is opens and when the secondary air passage is closed.

Abstract: A method for rapidly heating an emission control device in an engine exhaust uses excess air added to the exhaust via an air introduction device. After an engine cold start, the engine is operated to raise exhaust manifold temperature to a first predetermined value by operating the engine with a lean air-fuel ratio and retarded ignition timing. Once the exhaust manifold reaches the predetermined temperature value, the engine is switched to operate rich and air is added via the air introduction device. The added air and rich exhaust gas burn in the exhaust, thereby generating heat and raising catalyst temperature even more rapidly. The rich operation and excess air are continued until either engine airflow increases beyond a pre-selected value, or the emission control device reaches a desired temperature value. After the emission control device reaches the desired temperature, the engine is operated substantially around stoichiometry.

Abstract: The invention relates to a method and an arrangement for controlling a drive unit (1), especially of a vehicle, having a combustion engine (5). The method and arrangement make possible a correct charge control when utilizing a secondary air charger (10) as well as make possible a diagnosis of the secondary air charger (10). Secondary air is blown into an exhaust-gas system (15) of the combustion engine (5) via the secondary air charger (10). The secondary air charger (10) is driven by a pressure drop across an actuating element (20) for adjusting an air supply to the engine (5). The actuating element (20) is driven for adjusting an air supply to the engine (5) corrected in dependence upon an air mass flow driving a turbine (25) of the secondary air charger (10).

Abstract: In an arrangement for reducing exhaust emissions and utilizing the throttling energy of an internal combustion engine, a compressor and a generator are operatively connected to a turbine by which the intake air flow is controlled while transferring the throttling energy recuperated by the turbine to the compressor and the generator and, in the engine start-up phase, the compressor supplies fresh air to an engine air intake duct, the intake air flow volume being controlled by the energy withdrawn from the turbine via the compressor and the generator thus eliminating the need for a throttle valve in the fresh air intake line.

Abstract: The invention relates to a method and an arrangement for monitoring the operability of a secondary air system of an internal combustion engine having an exhaust-gas system. The secondary air system includes a secondary air pump. In the method and arrangement, a signal is determined which characterizes the secondary air flow. In the method, at least one signal of at least one operating characteristic variable of the secondary air pump is determined during the determination of the signal characterizing the secondary air flow and a conclusion is drawn as to a fault in the secondary air system when the signal of the at least one operating characteristic variable lies outside of a pregiven interval. The at least one signal of at least one operating characteristic variable is determined in dependence upon the operating state of the engine. This signal is determined from a signal for the pump current of an electrically operated secondary air pump.

Abstract: In a secondary air supply system, each of two branch portions of a secondary air supply pipe that is divided from a joint portion is provided with an air control valve, and the joint portion is provided with a pressure sensor and an auxiliary air control valve. The air control valves are opened at different timings such that pressure fluctuations in the joint portion upon opening of the firstly and the secondly opened air control valves are measured. An abnormality diagnosis is performed with respect to those two air control valves based on combinations of the aforementioned two pressure fluctuations.

Abstract: In one example, a system for an engine having an intake system and an exhaust system is described. The system comprises: an airflow sensor coupled to the intake system; an air pump having at least an inlet side and an outlet side, said inlet side having a first coupling to the intake system downstream of said airflow sensor, said outlet side having a second coupling to the exhaust system; and a controller coupled to the engine, said controller, during operation, identifying whether degradation has occurred to at least one of said first and second couplings, and providing an indication of said identified degradation. Various other examples are also disclosed.

Abstract: An engine control system and method maintains an optimum exhaust fuel to air ratio in an internal combustion engine. A secondary air injection (SAI) pressure is measured in an SAI system. The SAI pressure measurement is converted into an SAI flow value. A fuel compensation value is obtained based on the SAI flow value. Fuel delivery is compensated to the engine based on the fuel compensation value. In a second embodiment, the fuel compensation value is obtained based on the SAI pressure measurement. Fuel delivery is compensated to the engine based on the fuel compensation value. In a third embodiment, a primary flow value is calculated at an air intake of the engine. A fuel compensation value is calculated based on the SAI flow and primary flow values. Fuel delivery to the engine is compensated based on the fuel compensation value.

Abstract: A method and an apparatus for predicting intake manifold pressure are presented, to compensate for a large lag or a large time delay without producing an overshot or discontinuous behaviors of a predicted value. The method comprises the step of obtaining a difference of values of a variable to be predicted and a difference of values of another variable ahead of the variable to be predicted. The method further comprises the step of filtering the differences with adaptive filters. The method further comprises the step of obtaining a predicted difference of values of the variable to be predicted, through algorithm of estimation with fuzzy reasoning. The method further comprises the step of adding the predicted difference of values of the variable to be predicted, to a current value of the variable to be predicted, to obtain a predicted value of the variable to be predicted.

Abstract: In a secondary air injection system, MOSFETs control supply of electric current to an air pump and to a motor for driving an electromagnetic valve and to an electromagnetic coil to introduce secondary air into an exhaust gas passage upstream of a catalyst for purifying the exhaust gas of an internal combustion engine. Gate drive circuits control the MOSFETs based on an instruction from an ECU via input signal processing circuits. Abnormal conditions in the operation for controlling the air pump and the electromagnetic valve are detected, and, when an abnormal condition is detected, forcibly turn the MOSFETs off to interrupt the current to the motor and to the electromagnetic coil. A diagnosing circuit sends to the ECU diagnosis signals representing the state of controlling the load.

Abstract: A method and a device for implementing a method for ascertaining the load condition with an exhaust-gas component of a component arranged in an exhaust-gas region of an internal combustion engine is provided in which an increase in the exhaust-mass flow of the internal combustion engine and a detection of a pressure change in the exhaust-gas region in front of the component is specified. The load condition of the component is determined from the pressure change.

Abstract: In the disclosed secondary air supply system, an on-off valve (13) is driven by the discharge pressure of an air pump (12). A diaphragm chamber (44) is arranged in the neighborhood of a discharge outlet (54), and a part of the discharge air flows directly into the diaphragm chamber (44). Thus, the on-off valve (13) is positively operated even at high places with low atmospheric pressure and has a fast open/close response. As an electromagnetic actuator is not used to drive the on-off valve (13), the voltage supplied to the air pump (12) (DC motor (29)) does not drop inconveniently, and at the same time, the cost is reduced. Further, the number of the lead wires (65) is reduced.

Abstract: A burner for use in the emissions system of a lean burn internal combustion engine. The burner has a special burner head that enhances atomization of the burner fuel. Its combustion chamber is designed to be submersed in the engine exhaust line so that engine exhaust flows over the outer surface of the combustion chamber, thereby providing efficient heat transfer.

Abstract: In an electrical multi-purpose valve for supplying secondary air into an exhaust system of an internal combustion engine, in which a power-actuated closing member controls a valve orifice in a passage between an inlet from an air supply line and an outlet to the exhaust system, a non-return valve is arranged downstream of the closing body in the direction of the flow of the air through the valve between the non-return valve and the valve outlet, and baffle devices are provided which deflect exhaust gas entering the valve from the outlet at least once by an angle of about 90°.

Abstract: An anomaly judgment apparatus for a secondary air supply system which includes a secondary air supply path for introducing secondary air into an exhaust path of an internal combustion engine and an open-close valve disposed in the secondary air supply path. The valve is opened and/or closed by drive force of negative pressure introduced from a portion of an intake path of the engine downstream of a throttle valve. The anomaly judgment apparatus includes an anomaly judgment section for judging whether or not the secondary air supply system is anomalous; a negative pressure judgment section for judging whether or not the negative pressure is secured to a degree required for the drive force to reliably open and/or close the open-close valve; and an anomaly judgment prohibition section for prohibiting judgment by the anomaly judgment section when the negative pressure is not secured to the required degree.

Abstract: A diagnostic system according to the present invention diagnoses system failure of a secondary air injection system. The secondary air injection system includes a pump that provides air to an exhaust system via a conduit and a valve that controls the flow of air through the conduit. A pressure sensor measures pressure in the conduit. A controller predicts pressure in the conduit during first, second and third operational phases of the secondary air injection system. The controller compares the measured pressure to the predicted pressure to evaluate operation of the secondary air injection system. During the first phase, the secondary air injection system is used to reduce vehicle emissions. During the second phase, the valve is shut while the pump is on. During the third phase, the pump is turned off while the valve is closed.

Abstract: In an exhaust emission control system for an engine, comprising an exhaust emission control catalyst disposed in an exhaust muffler whose inside is divided into a plurality of chambers, at least a portion of the inside of the exhaust muffler is divided into a first chamber for converting mainly NOx in exhaust gas and a second chamber for converting HC and CO in the exhaust gas. The exhaust muffler comprises: a partition wall having a conduit for guiding the exhaust gas from the first chamber to the second chamber; an exhaust gas inlet for introducing the exhaust gas into the first chamber; an external-air suction means for sucking external air into the second chamber; and a discharge pipe for discharging the external air and the exhaust gas flowing through the second chamber.

Abstract: When the determination result of failure determination at a start of AI (auxiliary air injection=supply) is that there is a possibility of a closing anomaly due to freezing, a reevaluation process 1 being a reevaluation after a warm-up is performed. When the determination result of determination at an end of AI is that there is a possibility of an opening anomaly due to freezing, a reevaluation process 2 being a reevaluation after a warm-up is performed.

Abstract: An exhaust gas system for an internal combustion engine, in particular, of a motor vehicle has two mufflers through which the exhaust gas is able to flow in a parallel fashion. A switching unit makes it possible to selectively convey the exhaust gas flow of the internal combustion engine only or almost exclusively through the first muffler, or only or almost exclusively through the second muffler, or through both mufflers in a parallel fashion. The two mufflers are realized differently with respect to their muffling effect and/or flow resistance.

Abstract: The invention relates to a secondary air feeding apparatus and a method of detecting an abnormality in the apparatus capable of making a precise determination on abnormalities in components and detecting operational failures as well. According to one aspect of the invention, the opening-closing state of opening-closing means (ASV) is switched during the operation of an air pump, and abnormalities in respective components are detected on the basis of pressure values and pressure fluctuation values detected by a pressure sensor disposed between the air pump and the ASV before and after the switching of the opening-closing means.

Abstract: An internal combustion engine includes an air pump that supplies secondary air to an upstream side of an exhaust gas control catalyst in an exhaust pipe via a secondary air supply passage; an adjusting device that adjusts an intake air amount delivered into a combustion chamber from an intake pipe; and a controller that performs control for increase correction of the intake air amount adjusted by the adjusting device when the air pump performs an operation of supplying the secondary air. Thus, it is possible to prevent a problem caused by a reduction in an engine speed due to the secondary air supply.

Abstract: A method and an apparatus for determining the performance of a secondary air charging system for an internal combustion engine in order to determine the amount of secondary air supplied in the secondary air charging system. This is achieved by measuring the heat generated by the compression of the secondary air with temperature sensors. Insofar as the secondary air charging system is powered by a turbine arranged in parallel with the throttle valve in the intake tract, the measured temperature value for the compressor can be compared with a reduction in temperature of the intake air behind the turbine. Reliable information concerning the amount of secondary air supplied can be determined by simple sensors, thereby obviating the need for an air-mass sensor which is expensive to produce and sensitive to contamination.

Abstract: In an aircraft having an engine and an AMAD, a power take off shaft is rotationally connected to the engine, and the power take off shaft provides rotational power from the engine. A power producing device having an internal shaft is provided for producing additional auxiliary power. The power producing device may be an electrical generator with an internal shaft rotationally connected to the power take off shaft. The electrical generator converts one portion of the rotational power to additional electrical power, and fits in a pre-existing unused space within the aircraft, located between the engine and the AMAD. An output shaft is rotationally connected to the power take off shaft and rotationally connects to the AMAD to provide another portion of the rotational power to the AMAD. Additional electrical power generation is produced without modification to the engine, AMAD, or existing electrical generators.

Abstract: In an emission control apparatus of an internal combustion engine in which an emission control catalyst is disposed in an engine exhaust passage, if fuel cut is performed during a decelerating operation of the engine when the temperature of the emission control catalyst is to be quickly reduced by a secondary air supply device supplying fresh air to the emission control catalyst during the decelerating operation of the engine, the supply of fresh air from the secondary air supply device to the emission control catalyst is started after a fuel cut executing condition is met but before the fuel cut is actually executed. Therefore, the temperature of the catalyst is reduced before the exhaust air-fuel ratio shifts to the lean side due to execution of the fuel cut. Thus, exposure of the catalyst to a deteriorating condition of high temperature and lean air-fuel ratio is prevented.

Abstract: A method and an apparatus are described for the simultaneous adjustment of an air intake stream 24 of an internal combustion engine 10 and of a secondary air stream 21 into the exhaust system 12 of the internal combustion engine, the secondary air stream being produced by a compressor 20 which is driven by a turbine 18. The turbine 18 is housed in a bypass duct 16, the bypass duct being arranged parallel to a throttle valve 14 in the air intake tract 11 of the internal combustion engine. Thus the required amount of secondary air 21 is dependent upon the throttle valve setting. To create compensation for this, a control valve 32, for example, is created, which is connected through a connecting duct 4 to the secondary air duct 22.

Abstract: In order to improve the decrease of the catalytic action and the deterioration of the exhaust purification performance, a catalyst installed in the exhaust pipe of an engine and a secondary air pump for supplying secondary air into the exhaust pipe are provided, and the secondary air pump is operated even after the engine has stopped.

Abstract: A method of controlling emissions from a fixed-speed internal combustion engine includes injecting a controlled flow of air into the exhaust between a first catalyst bed adapted to reduce HC and NOx emissions, and a second catalyst bed adapted to reduce CO emissions. The flow of air is controlled to optimize the level of CO emissions, preferably as a function of engine load or temperature. In a marine engine-generator set, the flow of air is controlled as a function of generator load or temperature of the exhaust mixture entering the second catalyst bed, and seawater is injected into the exhaust stream downstream of the catalysts.

Abstract: In regeneration apparatus and method for a particulate filter that collects a particulate in exhaust gas of an internal combustion engine, a timing at which an accumulated particulate is combusted to regenerate the particulate filter is determined and a control is performed for a combustion of the particulate, during the control for the combustion of the particulate, a temperature of the engine exhaust gas is raised to a first target temperature set at a temperature equal to or higher than a criterion temperature which provides a criterion of whether the particulate is combusted to regenerate the particulate filter when the engine falls in a first driving region, and the engine exhaust gas temperature is raised to a second target temperature set at a temperature lower than the criterion temperature when the engine falls in a second driving region different from the first driving region.

Abstract: A method for rapidly heating an emission control device in an engine exhaust uses excess air added to the exhaust via an air introduction device. After an engine cold start, the engine is operated to raise exhaust manifold temperature to a first predetermined value by operating the engine with a lean air-fuel ratio and retarded ignition timing. Once the exhaust manifold reaches the predetermined temperature value, the engine is switched to operate rich and air is added via the air introduction device. The added air and rich exhaust gas burn in the exhaust, thereby generating heat and raising catalyst temperature even more rapidly. The rich operation and excess air are continued until either engine airflow increases beyond a pre-selected value, or the emission control device reaches a desired temperature value. After the emission control device reaches the desired temperature, the engine is operated substantially around stoichiometry.

Abstract: A bypass for an exhaust system for a utility vehicle, such as a combine, that, when substantially closed, provides maximum noise attenuation for road transport, i.e., relatively high back pressure, and then, when substantially open, would provide a reduced flow restriction, i.e., relatively low back pressure, for full power, field operation. A bypass flow path in an exhaust pipe is located upstream of a primary muffler. A diaphragm can be provided to manipulate a damper which acts to close the exhaust flow to the primary muffler and open the bypass to an exhaust pipe to effectively bypass the primary muffler.

Abstract: An exhaust gas purification system is provided with a first air fuel ratio controller which, when the amount of NOx deposited on an NOx adsorber catalyst reaches a predetermined level, alters an air fuel ratio of exhaust gas from a diesel engine to come into contact with the NOx adsorber catalyst, so as to cause the NOx adsorber catalyst to release NOx deposited thereupon; and with a device for setting a reference NOx level in accordance with a load of the diesel engine so that when the engine runs in a high load range, it is possible to reduce the frequent recourse to running at about stoichiometric air fuel ratio, by setting a reference level to a considerably high level, and to thereby restrict deterioration of the engine and rate of fuel consumption of the diesel engine to a least possible limit.

Abstract: A bypass for an exhaust system for a utility vehicle, such as a combine, that, when substantially closed, provides maximum noise attenuation for road transport, i.e., relatively high back pressure, and then, when substantially open, would provide a reduced flow restriction, i.e., relatively low back pressure, for full power, field operation. A bypass flow path in an exhaust pipe is located upstream of a primary muffler. A diaphragm can be provided to manipulate a damper which acts to close the exhaust flow to the primary muffler and open the bypass to an exhaust pipe to effectively bypass the primary muffler.

Abstract: A method is disclosed for controlling operation of an engine coupled to an exhaust treatment catalyst. Under predetermined conditions, the method operates an engine with a first group of cylinders combusting a lean air/fuel mixture and a second group of cylinders pumping air only (i.e., without fuel injection). In addition, the engine control method also provides the following features in combination with the above-described split air/lean mode: idle speed control, sensor diagnostics, air/fuel ratio control, adaptive learning, fuel vapor purging, catalyst temperature estimation, default operation, and exhaust gas and emission control device temperature control. In addition, the engine control method also changes to combusting in all cylinders under preselected operating conditions such as fuel vapor purging, manifold vacuum control, and purging of stored oxidants in an emission control device.

Abstract: An direct injected internal combustion engine includes a catalytic device for cleaning the exhaust gases of the engine. A control system of the engine is configured to adjust at least one of fuel injection timing, fuel injection duration and ignition timing so as to increase the temperature of the exhaust gases entering the catalytic device.

Abstract: A method for monitoring a secondary air system in combination with the exhaust-gas system of a motor vehicle is described. The method includes the steps of: providing a probe downstream of the junction of a secondary air line into the exhaust-gas channel; obtaining an air/fuel ratio (&lgr;exhaust gas) utilizing the probe; obtaining a signal for the intake air flow (massintake air); arithmetically determining the secondary air mass (masssecondary air) in dependence upon (a) the ratio of intake air flow to fuel (&lgr;engine), which is metered per unit of time; (b) the air/fuel ratio (&lgr;exhaust gas); and, (c) the signal for the intake air flow (massintake air); and, evaluating the operability of the secondary air system in dependence upon the secondary air mass (masssecondary air).

Abstract: The intake and exhaust control systems are operable in varying modes, according to the engine speed, by a single actuator. The intake control system includes an intake valve that allows a variable amount of air into an air cleaner depending on vehicle speed. The exhaust control system includes an exhaust control valve, and a primary and a secondary exhaust purifying system located downstream of the exhaust control valve. The flow into the exhaust purifying systems may also be controlled according to engine speed.

Abstract: A secondary air supply system includes a passage, which supplies the exhaust system of an internal engine with secondary air, an air pump, which supplies secondary air to the exhaust system through the passage, and a valve, which opens and closes the passage. The exhaust system includes an air-fuel ratio sensor for providing information on which abnormality tests are based. In a testing procedure, the air-fuel ratio is monitored under various conditions of the air pump and the value to determine whether the valve has failed to open or close and whether the pump has failed to start or stop.

Abstract: A secondary air system 10 is proposed for an internal combustion engine, which has a turbine 11 driven by a pressure gradient in the intake air and a compressor 14 driven by the turbine 11. The turbine is connected by a turbine inlet line 12 and a turbine outlet line 13 to an air intake duct 20. The compressor 14 has a compressor inlet line 15 and a compressor outlet line 16. The cold produced by the turbine 11 is used by a turbine heat exchanger 17 and transport lines 27 for the cooling of, e.g., oil. The heat produced by the compressor 14 is used by a compressor heat exchanger 18 and the transport lines 27 connected thereto, e.g., for heating air.

Abstract: A diesel-cycle engine with a unique exhaust gas recirculation system includes a plurality of cylinders with fuel feed for each of the cylinders and an intake manifold for distributing intake air to each of the cylinders for combustion of the fuel charges therein with generation of exhaust gas. The exhaust gas is discharged to ambient atmosphere through an exhaust line with a gas turbine therein. The gas turbine drives an intake compressor which serves to compress the intake air. An engine controller controls a valve regulating the amount of exhaust gas recirculation responsive to sensed concentration of an exhaust gas component. In another embodiment, an engine controller controls a valve regulating the amount of exhaust gas recirculation, responsive to sensed demand for torque and control of fuel injection quantity is responsive to sensed concentration of an exhaust gas component.

Abstract: An engine exhaust gas purification system having a catalyst in an exhaust system of the engine, said catalyst reducing nitrogen oxide when exhaust gas generated by the engine is in an oxidizing state. In the system, engine operating parameters, including at least an engine speed and an engine load, are determined and catalyst temperature is determined, and air/fuel ratio is controlled in response to the detected parameters and the determined catalyst temperature, thereby enabling the catalyst to purify NOx in its optimum temperature characteristic range to achieve enhanced NOx constituent purification performance in an oxidizing environment. Alternatively, the air/fuel ratio is controlled in the stoichiometric or richer direction when the catalyst temperature is high, thereby protecting the catalyst from being damaged. The catalyst is a selective-reduction type nitrogen oxide reduction catalyst.

Abstract: In an air supply arrangement for an internal combustion engine, particularly for motor vehicles having devices for cooling the engine and for supplying exhaust gas secondary air to the exhaust system of the engine, a single air pump driven by an electric motor is provided for supplying air to the engine cooling system and to the exhaust system and devices for switching the air flow supplied by the air pump to either the engine cooling system or the engine exhaust system are provided. A control unit is also provided which controls the electric motor depending on the amount and pressure of the air needed for the cooling system and the engine exhaust system.

Abstract: An exhaust gas-purifying system for an internal combustion engine comprises an exhaust gas-purifying device arranged in the exhaust system of the engine and accommodating a nitrogen oxide absorbent for absorbing nitrogen oxides in exhaust gases emitted from the engine when the engine operates in a state where the air-fuel ratio of the exhaust gases is leaner than a stoichiometric air-fuel ratio. A cylinder internal pressure sensor detects pressure within at least one of the cylinders of the engine. The amount of nitrogen oxides generated within the engine is determined based on the pressure within the at least one of the cylinders. It is determined whether the amount of nitrogen oxides absorbed by the nitrogen oxide absorbent has been saturated, based on the determined amount of nitrogen oxides.

Abstract: A secondary air pump communicates through an air duct with an exhaust gas line of an internal combustion engine. A catalytic converter for cleaning exhaust gas is connected in the exhaust gas line. The secondary air mass pumped by the secondary air pump is measured with an air flow rate meter. A control unit compares the measured secondary air mass with the desired secondary air mass set by the control unit. If the measured secondary air mass differs from the set secondary air mass by more than a specified amount, then the control unit has detected a malfunction.