Abstract: An exhaust system for a motor vehicle engine includes mixing vent flaps in the exhaust pipe which open responsive to exhaust temperature. The vent flap forms a portion of the exhaust pipe when closed and is pivotally attached along one edge to the exhaust pipe to open inwardly into the exhaust pipe to constrict and accelerate flow in the pipe to allow outside air to be drawn into the exhaust pipe. A magnetic catch latches the vent flap in its closed position and a magnetic release responsive to increased temperature of the exhaust stream releases the vent flap.

Abstract: A second air flow control apparatus disposed between an air inlet port of an engine and an exhaust port includes a body, a base, a moving member, and a gas thread. The body has a cavity, an air inlet and an air outlet, the air inlet and the air outlet being connected through the cavity. The base is fixed in the cavity, having at least an opening for controlling the air flow through the air flowing path. The moving member is pivotably disposed in the cavity or the base by a spring force and having at least a gate and a cover configured for controlling the area of the opening. The gas thread is connected to the moving member and configured for pulling the moving member to generate a processional rotation and a resetting rotation. The rotations are configured for controlling the gate and the cover part to adjust the opening area of the opening so as to precisely control the second air flow.

Abstract: A secondary air supply system in which individual members may be arranged to be disposed on substantially the same straight line in an engine, whereby connection path lengths are reduced and the attachment thereof is facilitated. The secondary air supply system may be provided between an air cleaner and attached to an engine and an exhaust port of the engine. The secondary air supply system has a secondary air control valve, a lead valve and secondary air supply paths which connect the air cleaner, the secondary air control valve and the lead valve together and supply air to the exhaust port from the air cleaner. The air cleaner, the secondary air control valve and the lead valve may be arranged to be disposed on substantially the same straight line when viewed from the side.

Abstract: An air-fuel ratio control apparatus of an internal combustion engine includes: an exhaust gas purifying catalyst disposed in an exhaust passage of the internal combustion engine; fuel cutting means for cutting fuel to be supplied to the internal combustion engine at the time of deceleration of the internal combustion engine; and catalyst degradation suppressing means for suppressing degradation of the exhaust gas purifying catalyst by prohibiting operation of the fuel cutting means when it is determined that the degradation of the exhaust gas purifying catalyst advances, wherein the catalyst degradation suppressing means sets an operation permitting period, during which the operation of the fuel cutting means is permitted after completion of a fuel quantity increasing operation of the internal combustion engine.

Abstract: A method of managing vapors generated from an ammonia-containing reductant delivery system for an engine of a vehicle, comprising of during at least a portion of engine-off conditions, storing ammonia containing vapors generated in the reductant delivery system, and after said storing and during at least a portion of engine operation, purging said stored ammonia into an exhaust of the engine to react in a catalyst in the exhaust flow.

Abstract: A combustion engine comprising an exhaust system containing a particulate filter (10, 52) for trapping particulate matter in engine exhaust passing through the exhaust system. A particulate trapping medium (18) inside a casing is selectively operable to a relatively lesser porosity for trapping particulate matter in the exhaust and to a relatively greater porosity for facilitating removal of trapped particulate matter during cleaning.

Abstract: Clogging of an injection nozzle which supplies a reducing agent to the exhaust gas on an upstream side of a reduction catalyst in the exhaust gas passage is prevented, and the efficiency of NOx purification processing is improved. A reducing agent supply unit uses a detection signal of the exhaust gas temperature from a temperature detection device to set a supply quantity at or above a lower limit for cooling the interior of an injection nozzle to below the temperature at which urea water crystallizes, for the detected exhaust gas temperature, and supplies urea water to the injection nozzle at the set supply quantity. By such supply of urea water, the interior of the injection nozzle is cooled to below the temperature at which the urea water crystallizes. As a result, the urea water does not crystallize inside the injection nozzle, and clogging of the injection nozzle can be prevented.

Abstract: A seal arrangement for a secondary air charging system includes a seal sealing a gap between an intake opening of the secondary air charging system and a downstream surface of an air intake filter.

Abstract: An ECU executes a program including a step (S102) of limiting the maximum opening amount of a throttle valve to TH (1) when failure has occurred in a pressure sensor (“YES” in step S100); a step (S202) of limiting the maximum opening amount to TH (2) when open failure has occurred in at least one of two vacuum pressure ASVs provided for banks of a V-type engine, and an electromagnetic ASV (“YES” in step S200); a step (S302) of limiting the maximum opening amount to TH (3) when open failure has occurred in both of the vacuum pressure ASVs (“YES” in step S300); a step (S402) of limiting the maximum opening amount to TH (4) when open failure has occurred in one of the vacuum pressure ASVs (“YES” in step S400); and a step (S502) of reducing the throttle valve opening amount TH to the limited maximum opening amount.

Abstract: There is provided an air supply apparatus for an engine comprising a plurality of exhaust pipes and catalysts arranged in the exhaust pipes, respectively, the apparatus comprising devices for supplying air into the interior of the corresponding exhaust pipes upstream of the corresponding catalysts, respectively.

Abstract: A hydraulic assembly and method for use with an vehicle engine exhaust flow control valve for controlling flow to at least one intake supply. The assembly has an actuator, such as a spring return piston cylinder, for positioning the control valve. An inlet passage, communicating with the cylinder, is arranged for supplying hydraulic fluid to a side of the actuator and a drain is arranged for draining the hydraulic fluid from the side of the actuator. An on-off type hydraulic valve, communicating with the drain, is operably coupled to the cylinder for controlling communication of the hydraulic fluid from the cylinder side to the drain. When the hydraulic assembly is in use, the pressure of hydraulic fluid acting on the actuator is adjustable by operation of the on-off type valve thereby to control movement of the actuator and, in turn, movement of the control valve.

Abstract: A method for controlling the amount of secondary air of a motor vehicle, which has a device for injecting secondary air. The increase in the injected amount of secondary air is carried out as a function of the starting conditions of the motor vehicle and the heating progression of the catalytic converter determined by modeling and/or measurement, and is variable over time.

Abstract: The present invention relates to a secondary air injection system for an internal combustion engine, and an automotive vehicle comprising such a secondary air injection system. The arrangement includes shut-off valve for selectively passing on or restricting airflow form the secondary air injection system. A flexible connector is arranged to receive the airflow and pass it on to at least two reed-type non-return valves arranged to substantially only allow airflow in the downstream direction. At the downstream side of each respective reed-type non-return valve a conduit for communicating any airflow passed there through to an associated exhaust bank of the internal combustion engine.

Abstract: Injection of secondary air into an exhaust of an automotive vehicle at a location upstream of a catalytic converter of the vehicle in which the airflow rate is calculated by the air injection system pressure and by the pulsation of the air injection system pressure in reference to stored values in a data table.

Abstract: An apparatus comprises a combustion engine, an emission abatement device, and a turbocharger. The emission abatement device is fluidly coupled to the engine to receive exhaust gas therefrom. The turbocharger comprises an air compressor that is fluidly coupled to the engine to supply pressurized air to the engine and that is fluidly coupled to the emission abatement device via a flow path not including any combustion section of the engine to supply pressurized air to the emission abatement device. An associated method is disclosed.

Abstract: The invention concerns an exhaust gas cooler employed with a tailpipe of a vehicle exhaust system and a method of cooling exhaust gasses before being emitted from the exhaust system into the atmosphere. The exhaust gas cooler may include a cooler housing having a substantially cylindrical shape with an open forward edge, an open rearward edge, and an internal diameter that is larger than the external diameter of the tailpipe, and a cooler support attached to and supporting the cooler housing such that the rearward edge of the tailpipe is located within the cooler housing between the forward and rearward edges of the cooler housing.

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: Injection of secondary air into an exhaust of an automotive vehicle at a location upstream of a catalytic converter of the vehicle in which the airflow rate is calculated by the air injection system pressure and by the pulsation of the air injection system pressure in reference to stored values in a data table.

Abstract: Exhaust passage control valve 10 may comprise housing 30, valve member 20, and helical torsion spring 40. Housing 30 has an exhaust passage. Exhaust gas from an internal combustion engine flows through the exhaust passage of the housing 30. Valve member 20 opens and closes the exhaust passage of the housing. Helical torsion spring 40 may be disposed at the opposite side of the valve member from the housing side thereof. Helical torsion spring 40 comprises a coil part wherein spring wires have been wound in a coil shape, and arms formed at both ends of the coil part. The coil part may be disposed at approximately the center of the valve member. When the arms bend with respect to the coil part, the counter-force of this bending energizes the valve member towards a closing side. The spring mounting member may be arranged and constructed to adjust a position in which the spring mounting member is mounted on the housing such that a rotation angle of the arms can be changed.

Abstract: A muffler device with catalysts for improving purifying exhaust gas of nitrogen oxides within a motorcycle exhaust pipe comprises a muffler divided into three chambers, a first chamber, a second chamber, and a third chamber; a front exhaust pipe; a front reduction catalyst; a rear exhaust pipe provided with a secondary air inlet behind the reduction catalyst for introducing secondary air therein. Thereby, the exhaust gas from an engine with air-to-fuel ratio less than or equal to 14.7 will firstly pass the reduction catalyst to have its nitrogen oxides (NOX) effectively inverted into nitrogen (N2) and oxygen (O2), and then secondary air will be added to the exhaust gas so as to increase its air-to-fuel ratio to larger than 14.7, and finally the exhaust gas will pass the oxidation catalyst to have its carbon monoxide (CO) and hydrocarbons (HC) effectively inverted into carbon dioxide (CO2) and water (H2O).

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: A 4-cycle engine for a motorcycle has a secondary-air supplier for supplying secondary air to exhaust ducts. The engine includes a recess, which is depressed toward the engine, on a cylinder-head cover for holding a control valve of the secondary-air supplier. The recess and the control valve are positioned between two innermost cylinders of the array of the cylinders. Check valves, which are connected to downstream regions of the control valve, are each disposed between two outermost cylinders of the array of the cylinders.

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: An engine blowby injection system including a blowby passage, and a blowby injector with a blowby flow outlet sized to inject the blowby flow into an exhaust gas flow generated by an internal combustion engine. The blowby injector includes a cooling mechanism for cooling the blowby flow outlet to reduce the likelihood of carboning. In one embodiment, the blowby injector includes an adapter, an injector body including an injector nozzle with the blowby flow outlet, and a flow passage that allows cooling air to flow therethrough. A method of injecting blowby flow from an internal combustion engine is also provided.

Abstract: A reed valve having a plate shaped support substrate with a valve hole formed in a central section passing through in a plate thickness direction is provided. A flexible plate-shaped reed covering the valve hole at one surface of the support substrate and having one end in a longitudinal direction that is fixed to the support substrate. The support substrate has a rib extending along a center line in a longitudinal direction of the inside of the valve hole, to divide the valve hole into two spaces. A surface of the rib opposite to the reed is positioned on substantially the same plane as a surface of the support substrate to which the rib is attached, and is adjacent to the reed.

Abstract: A secondary air pressure detecting apparatus includes a solenoid valve and a pressure sensor. The solenoid valve defines a secondary air passage that introduces secondary air from the air pump into the exhaust system of an engine. The solenoid valve opens and closes the secondary air passage. The pressure sensor is integrally mounted to the solenoid valve to detect pressure of secondary air in the solenoid valve. The solenoid valve includes a coil assembly and magnetic members. The coil assembly includes a solenoid coil that generates magnetic force when the solenoid coil is energized. The magnetic members construct a magnetic circuit with the solenoid coil. The magnetic circuit is arranged outside of the secondary air passage. The pressure sensor is arranged on an opposite side of the secondary air passage with respect to the magnetic circuit.

Abstract: Hydrogen-rich reformate gas is produced by a fuel reformer (2) from fuel vapor containing hydrocarbon, which is produced by a fuel vaporizer (6), by means of a partial oxidation reaction and a steam reforming reaction. A fuel injector (8, 9) supplies fuel to the fuel vaporizer (6), and an air injector (8a) supplies air to the fuel vaporizer (6). A glow plug (13) partially oxidizes the air-fuel mixture inside the fuel vaporizer (6). By controlling the air supply amount in relation to the fuel supply amount to obtain an excess air factor corresponding to a predetermined rich air-fuel ratio, a part of the air-fuel mixture in the fuel vaporizer (6) is partially oxidized, and the remaining fuel vapor is heated by the oxidation heat. As a result, the partial oxidation reaction and steam reforming reaction in the fuel reformer (2) are performed with a favorable balance.

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: An internal combustion engine is supplied with reformate from a hydrocarbon reformer at engine start-up and during engine warm-up. The reformate fuel mixture is fuel-lean at start-up to ensure that all the fuel is burned while the exhaust converter is thermally non-functional. Shortly after start-up, the mixture is changed to be fuel-rich, providing unburned reformate fuel in the exhaust stream. During start-up and warm-up, the output of an air pump is controllably divided between the reformer (primary air) and the engine exhaust system (secondary air). Unburned reformate from the engine and secondary air from the air pump ignite and thereby rapidly heat the converter. Gasoline or diesel fueling of the engine by fuel injection is preferably delayed until the engine and the converter both reach operating temperatures, whereupon the engine is fueled by fuel injection and further reforming is terminated.

Abstract: A secondary air supplying apparatus of the present invention comprises a secondary air supplying device for supplying secondary air to upstream of an emission purifying device in an exhaust system of an internal combustion engine, a coolant temperature sensor for detecting a temperature of a coolant for the engine, an intake air temperature sensor for detecting a temperature of intake air, a supply controller for actuating the secondary air supplying device in accordance with a predetermined secondary air supply condition, and a summing unit for summing an actuation period of the secondary air supplying device and storing a sum. The supply controller stops the secondary air supply by the secondary air supplying device when the sum stored by the summing unit reaches a predetermined upper limit.

Abstract: An apparatus for posttreatment of exhaust gases of an internal combustion engine, using a reducing agent to be introduced into the exhaust gases, in particular a urea or a urea-and-water solution, having an improved mixing chamber into which stored reducing agent, via a reducing agent line, and compressed air via a compressed air line can be introduced to create a reducing agent-air mixture, and means for preventing a reverse flow of reducing agent or reducing agent-air mixture from the mixing chamber into the compressed air line are provided which have a spring-loaded sealing hose. This arrangement assures secure sealing off of an attachable compressed air system from the corrosive reducing agent.

Abstract: A secondary air supply apparatus controls emissions from an engine through secondary combustion of combustible matters in exhaust gas accomplished by supplying air to an exhaust pipe upstream of an emission control device. A pressure behavior pattern is determined from a pressure value detected by a pressure sensor disposed between an air pump and an open-close valve, and a pressure variation value. The secondary air supply apparatus determines operational states of the air pump and the open-close valve based on variations of the pressure behavior pattern at the time of a secondary air supply control and at the time of a secondary air stop control.

Abstract: A method and apparatus to reduce the emissions of an exhaust stream is provided. One feature of the present invention includes a control unit for metering a reagent into the exhaust stream. The control unit adjusts a quantity of the reagent to be metered into the exhaust stream. One embodiment of the present invention concerns a method of removing nitrogen oxides in exhaust gases from a diesel engine by introducing ammonia into the exhaust stream. This Abstract is provided for the sole purpose of complying with the Abstract requirement rules that allow a reader to quickly ascertain the subject matter of the disclosure contained herein. This Abstract is submitted with the explicit understanding that it will not be used to interpret or to limit the scope or the meaning of the claims.

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: 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: 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: The internal combustion engine has at least two partly separate exhaust systems in each of which are disposed a catalytic converter, and upstream thereof, a lambda probe. There is provided a secondary air pump and a number of individual secondary air lines, corresponding to the number of exhaust systems, for delivering secondary air to the respective exhaust systems. From the signal of at least one air mass meter, a value is determined for the total air mass flow introduced into the exhaust systems. In order to determine the air mass actually introduced into the individual exhaust systems, the output signals from the lambda probes in the exhaust systems are used to identify an uneven distribution of the air mass fed to the individual exhaust systems.

Abstract: In an engine intake A/F ratio control system in an outboard engine system, a secondary air passage (P) for supplying secondary air for regulating the A/F ratio of an air-fuel mixture is connected to a carburetor (33) in an intake system of an engine (E), and a duty control valve (68) is connected to the secondary air passage (P). A duty control unit (92) is connected to the duty control valve (68) for controlling the duty ratio of a pulse applied to a coil (76) of the duty control valve (68), and an LAF sensor (94) is mounted to an exhaust system for detecting an A/F ratio of an exhaust gas to input a detection signal proportional to the A/F ratio of the exhaust gas to the duty control unit (92).

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: 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: An electronic control device and method for determining the fuel quantity at which a burner is operated whose exhaust gas mixes with the exhaust gas of an internal combustion engine in an exhaust-gas system in front of a catalytic converter, in which a first oxygen concentration in the exhaust gas of the internal combustion engine is measured spatially before the mixing of the exhaust gas of the burner with the exhaust gas of the combustion engine, a second oxygen concentration in the intermixed exhaust gas is measured, and the fuel quantity at which the burner is operated is determined on the basis of processing the first oxygen concentration and the second oxygen concentration.

Abstract: In a cold condition before a warming-up completion in a diesel engine, when an engine power is less than a predetermined value, an air excess rate is controlled to a second air excess rate being smaller than a target air excess rate set after the warming-up completion, thereby promoting a warming-up of an exhaust gas purification catalyst due to rise of an exhaust gas temperature, and when the engine power is more than the predetermined value, the air excess rate is controlled to a first air excess rate being larger than the target air excess rate, thereby decreasing HC emission quantity from a combustion chamber. Accordingly, a total emission quantity of HC at the clod condition is decreased.

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: A method and system are provided for controlling the air/fuel ratio provided to an internal combustion engine during the time period when a hydrocarbon trap, coupled downstream of time engine, is being purged. In particular, the air/fuel ratio provided to the engine is biased rich of stoichiometry when the downstream hydrocarbon trap is being purged.

Abstract: In order to prevent a catalyst for an internal combustion engine from decreasing efficiency by deterioration after long time use of the catalyst, the decreased efficiency of the catalyst is determined, and the internal engine is controlled based on results of the determination so as to maintain high efficiency of the catalyst. The catalyst is installed in an exhaust pipe of the engine. Sensors for detecting conditions of exhaust gas both at upstream side and downstream side of the catalyst are provided, respectively. As for the sensor, for example, an oxygen sensor of which output varies stepwise at &lgr;=1, or a sensor of which output varies in proportion to air-fuel ratio can be used. Detected values of the sensors are taken into a control unit, eliminating efficiency and deteriorating degree of the catalyst are estimated by comparison of the detected values, and the engine is controlled so that the eliminating efficiency becomes maximum.

Abstract: A reciprocating piston engine (2) includes an exhaust system comprising an exhaust pipe (8) which communicates with a silencer (10), whose upstream portion (11) is divergent in the direction of gas flow through it, an oxidising catalyst (12) and an air supply pipe (14) communicating with the exhaust pipe at a position upstream of the catalyst and silencer. The air supply pipe (14) includes a Reed valve (16) which is adapted to open under a pressure differential to permit air to flow into the exhaust pipe. In order to maximise the air flow into the exhaust pipe the effect of pressure pulses within the exhaust pipe is utilised and for this purpose 3L2−(2L1+L2) is equal to ±0.25 to 0.

Abstract: A method of operating a combustion apparatus such as an internal combustion engine is described, in which the apparatus includes at least one combustion chamber with an inlet port for primary combustion air, an apparatus to introduce into the combustion chamber primary fuel for combustion with the primary air, an exhaust port for combustion products, and an exhaust system for exhausting the combustion products to atmosphere, the method including introducing into the exhaust system secondary air, mechanically acting upon the secondary air and products of combustion in the exhaust system in the presence of a catalyst, to produce a reformed fuel, introducing the reformed fuel into the combustion chamber for combustion with primary fuel and primary air.

Abstract: An internal combustion engine has a preparation device for fuel, for the purpose of providing a starting fuel which comprises low-boiling fuel constituents. A catalytic converter is accommodated in an exhaust train of the internal combustion engine. After-treatment of the exhaust gases is carried out by a secondary air device, by means of the combustion being carried out with an excess of starting fuel for rich-burn operation during the cold start and the subsequent warm-up phase. The system is provided for spark-ignition mixture-compressing or spark-ignition direct injection internal combustion engines.

Abstract: An internal combustion engine (1), especially of a motor vehicle, is described which is provided with a combustion chamber (4) into which fuel can be injected in a first operating mode during a compression phase and in a second operating mode during an induction phase. An exhaust-gas pipe (8) is provided in which a catalytic converter (12) is mounted. The engine (1) is provided with an exhaust-gas recirculation from the exhaust-gas pipe (8) to an intake manifold (7). A control apparatus (18) is provided for controlling (open loop and/or closed loop) operating variables of the engine (1). The exhaust-gas recirculation rate of the exhaust-gas recirculation is controllable (open loop and/or closed loop) by the control apparatus (18), inter alia, in dependence upon the temperature of the catalytic converter (12).