Abstract: The invention concerns an arrangement for a discharge system for combustion gases from a motor-driven vehicle which gives the vehicle a low IR signature. According to the invention, the gas outflow channel (28), at least in an area of the channel adjacent to the discharge aperture (32), has a boundary wall (34) which is perforated right up to the open discharge aperture (32) and surrounded by a cooling air channel (38). The arrangement is such that cooling air can sweep over the inner side as well as the outer side of the perforated wall (34).

Abstract: Various embodiments of air control valves are disclosed. Each has a mechanism, controlled by a solenoid and by the difference between fluid pressure at its inlet and fluid pressure at its outlet, for allowing communication between an air pump and an exhaust gas treatment system as long as fluid pressure at the outlet does not exceed fluid pressure at the inlet by more than a predetermined difference during absence of a predetermined electric energization of the solenoid, for disallowing communication between the air pump and the gas treatment system during presence of the predetermined electric energization of the solenoid, and for disallowing communication between the air pump and the gas treatment system whenever fluid pressure at the outlet exceeds fluid pressure at the inlet by more than the predetermined difference.

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: An integrated thermal and exhaust management unit for a vehicle comprises a housing defining a chamber and having an inlet through which engine exhaust gas flows. A fuel-fired heater is adjacent to the housing and is operable to heat the engine exhaust gas flowing through the chamber. A catalytic converter is adjacent to and in downstream flow communication with the chamber for catalyzing the engine exhaust gas flowing therethrough. An exhaust gas heat recovery unit is radially adjacent to and in downstream flow communication with the catalytic converter for exchanging exhaust gas heat to liquid heat for transferring to heat-requiring areas of the vehicle. A controller controls the operation of the management unit whereby the fuel-fired heater is powered if the catalyst temperature is less than a catalyst light-off temperature for efficient treatment of vehicle emissions.

Abstract: An on-board reductant delivery system for a motor vehicle includes a mixer/nozzle system for connection to an exhaust system of a motor vehicle. The on-board reductant delivery system also includes a fluid metering system connected to the mixer/nozzle system for metering reductants to the mixer/nozzle system. The on-board reductant delivery system further includes an air supply system connected to the mixer/nozzle system for delivering pressurized air to the mixer/nozzle system. The mixer/nozzle system mixes the reductants and pressurized air and sprays the mixture in the exhaust system of the motor vehicle to reduce NOx.

Abstract: An exhaust gas purifying system for an automotive internal combustion engine which discharges oxygen-excessive exhaust gas under lean-burn operation. The exhaust gas purifying system comprises a NOx reducing catalyst for reducing NOx in the presence of at least hydrogen serving as reducing agent. The NOx reducing catalyst is disposed in an exhaust gas passageway of the engine. The NOx reducing catalyst includes a porous substrate, and platinum and cesium carried on the porous substrate. A catalyst is disposed in the exhaust gas passageway in order to produce hydrogen so as to enrich the oxygen-excessive exhaust gas with hydrogen before the oxygen-excessive exhaust gas reaches the NOx reducing catalyst. The oxygen-excessive exhaust gas enriched with hydrogen is introduced through the exhaust gas passageway to the NOx reducing catalyst.

Abstract: To provide an exhaust secondary air system intended to shorten the length of secondary air feed pipes connected to an exhaust secondary air valve thereby making compact the exhaust secondary air system including the secondary air feed pipes, and also to cool the exhaust secondary air valve and the secondary air feed pipes with running wind. A saddle-type vehicle includes a main frame extending rearwardly from a head pipe; a down frame extending downwardly from the head pipe; an engine disposed under the main frame and behind the down frame; and an exhaust secondary air valve, connected to a secondary air feed pipe, for feeding secondary air to an exhaust passage of the engine via the secondary air feed pipe; wherein the exhaust secondary air-valve is mounted on the down frame.

Abstract: A method and apparatus are provided for improving the conversion efficiency of a catalytic converter for treating exhaust gases produced from the combustion of a fuel to at least reduce pollutants from incomplete combustion, wherein the reduction in pollutants is achieved by the introduction of ozone, upstream from the catalytic converter, to improve the efficiency of the catalytic converter.

Abstract: A heat exchanger for heating cleaning liquid with exhaust gasses from an internal combustion engine that have been treated by a catalytic converter further includes an arrangement for injecting fuel into the gases to further provide heat in the exchanger.

Abstract: In an arrangement and method for controlling a supercharged internal combustion engine having a charger arranged in the air intake duct and a catalytic converter arranged in the exhaust duct, with a secondary air duct including a control valve extending from a point of the intake duct downstream of the charger and upstream of a first throttle member to a point of the exhaust duct upstream of the catalytic converter, a second throttle member is arranged in the intake duct upstream of the charger and the throttle members and control valve are controlled by a control unit in such a way that sufficient air is supplied to the exhaust duct upstream of the catalytic converter such that, during engine warm-up, combustion takes place in the catalytic converter causing rapid heat-up of the catalytic converter.

Abstract: A secondary air supply system, for an internal combustion engine having a closed crankcase includes a diaphragm air pump. The pumping chamber has one way valves such that ambient air may enter the pumping chamber only through the inlet port and exit the pumping chamber only through the outlet port to supply secondary air to the exhaust system. The actuating chamber of the diaphragm air pump is in airflow communication with the engine crankcase. The diaphragm air pump has a biasing means, either integral to the diaphragm or by a spring which acts on the diaphragm. The biasing means is calibrated to minimize the intensity differential between the positive and negative crankcase pressure pulses.

Abstract: The method according to the invention is based on the discovery that the pollutant emissions in the first minutes of operation of an internal combustion engine also depend on the preceding operation and switching off procedure. It is suggested to subject the internal combustion engine and the catalytic converter to a cleaning or a scavenging phase before the standstill of the motor. With this cleaning or scavenging phase the movement of the internal combustion engine is still maintained for a certain time before standstill of the motor either by sparking or by an external drive and at least temporally in at least individual cylinders of the internal combustion engine the supply of fuel is interrupted and exclusively air is delivered. By way of this it is achieved that the remaining pollutants accumulated in the internal combustion engine are supplied to the catalytic converter which is still at the operating temperature and the catalytic converter is enriched with oxygen.

Abstract: A secondary air supply control system controls supply of air to a catalyst arranged in the exhaust passage of an internal combustion, for purification of exhaust gases. A temperature difference between a temperature of an engine coolant sensed at a stoppage of the engine and stored and a temperature of the engine coolant sensed at a start of the engine after the stoppage is calculated. It is determined whether or not a stop time period between the stoppage and the start of the engine is short, depending on the temperature difference. When it is determined that the stop time period is short, an operation time period over which the air pump is to be operated to supply air to the catalyst is corrected based on a temperature difference between a temperature of the engine coolant sensed at the start of the engine and a temperature of intake air sensed at the start of the engine.

Abstract: An injection valve of a reducing agent metering device is enclosed in a double-walled valve holding element that is connected directly to the exhaust-gas line. It is thereby possible to blow pressurized air into an air gap between an outer wall and an inner wall of the valve holding element and, as a result, to cool at least those parts of the injection valve that are in close vicinity to the exhaust gas.

Abstract: An exhaust gas purification system for an engine equipped with a turbocharger and an exhaust pipe having a NOx conversion catalyst therein. The system comprises a reservoir for storing pressurized air received from the turbocharger, a reductant injector in fluid communication with a reductant supply, and a mixing chamber in fluid communication with the reservoir and connected to the reductant injector. The reductant injector is responsive to an injection signal for atomizing and injecting a quantity of reductant into the mixing chamber. The mixing chamber is in fluid communication with the exhaust pipe for introducing a quantity of air and reductant mixture into the exhaust gas flow upstream of the NOx conversion catalyst.

Abstract: A secondary air injection system for reducing the hydrocarbon emissions of an internal combustion engine that is provided with an air pump supplying air to the exhaust manifold of the engine through a check valve assembly and an elastomeric hose characterized in that a baffle in the shape of a helix is located internally within the hose so as to cause the exhaust pressure waves from the engine and passing beyond the check valve assembly to impinge upon the solid compound surface of the baffle and be divided and diffused as they progress along spiraling paths so as to prevent objectionable noises being generated in the hose by the pressure waves.

Abstract: An exhaust system for an internal combustion engine. A plenum chamber has two ports, one which is connected to a header tube for conducting a stream of exhaust gas and another which is connected to a ram tube adapted to collect outside air provided by movement of a vehicle in which the internal combustion engine is installed. The plenum chamber is constructed so that the outside air is caused to travel thereinside at least a substantially non-zero set-back distance before being permitted to join the stream of exhaust gas. Preferably, the exhaust system also includes one or more reverse flow controllers associated with respective cylinders of the internal combustion engine, downstream from the exhaust ports thereof.

Abstract: A muffler for an internal combustion engine has a vertically elongated expansion chamber into which an exhaust gas from the exhaust port of internal combustion engine is introduced. The expansion chamber is separated level-wise into a first expansion chamber and a second expansion chamber by a partition plate. An exhaust emission purifier formed of an oxidation catalyst is attached to the partition plate, thereby allowing the exhaust gas ejected from the exhaust port to be introduced into the second expansion chamber from the first expansion chamber via the exhaust emission purifier. The exhaust emission purifier is spaced apart from the exhaust port by a predetermined distance in a direction orthogonal to an ejecting direction of the exhaust gas.

Abstract: Internal combustion engine exhaust gas, passing unreacted through an exhaust gas catalytic or thermal reaction device during the warm-up period of the device, are directed to a rigid conduit that retains the entire flow. The conduit retains the unreacted gas in sequential alignment with a second non-harmful gas occupying the conduit prior to inflow of the unreacted gas. The second gas blocks flow of the unreacted gas out of the downstream end of the conduit and into the atmosphere. The length and diameter of the conduit minimizes mixing of the unreacted gas and the second gas, and minimizes the volume of the conduit required to retain the unreacted gas. After warm-up of the reaction device, the retained unreacted gas is recirculated to the engine induction system or the reaction device. This approach supplements the emission control of the reaction device by preventing emission of undesirable exhaust gas constituents during starting of the engine and warm-up of the reaction device.

Abstract: An exhaust manifold device is provided to allow air to enter an exhaust manifold during normal operation of an engine to prevent exhaust gases being sucked into the cylinders via exhaust valves. Air can be supplied via valves (18 and 21) to the exhaust manifold as required and is supplied to the valve (21) at pressures, above atmospheric pressure, that increase with engine speed.

Abstract: A secondary air system for an internal combustion engine (32), including at least one line (14) through which air is blown into the exhaust pipe of the engine, a pump (26) and a drive (27) for the pump (26). In addition an air-feed line (13) is provided through which the secondary air is supplied to the pump (26). The power necessary to drive the pump is provided by the engine (32).

Abstract: An improved anti-coking air injection reaction system in which individual air passages in the engine cylinder head are provided with electrical resistance heating elements that are periodically activated to develop radiant energy that bums off coke deposits formed on the passage side-walls. The heating elements are conveniently implemented with conventional glow plugs. A controller monitors engine operating parameters to identify conditions likely to result in the formation of coke deposits, and schedules activation of the heating elements in relation to the frequency of the identified conditions or the cumulative time of engine operation. The heating elements may be activated sequentially or in banks to reduce electrical loading, and the activation is preferably scheduled during non-critical operating conditions defined by specified ranges of coolant temperature and engine speed and/or load.

Abstract: The temperatures of exhaust gas streams into a black smoke eliminating device are uniformly raised to assuredly burn and eliminate the black smoke at the black smoke eliminating device. Accordingly, the restoration of the black smoke eliminating device is uniformly carried out while avoiding melt damage of the filter. Further, the exit temperature of the black smoke eliminating device is descended by a simple device of lower cost. For accomplishment of the present objects, the heating device and black smoke eliminating device are provided in a plural and divided manner and there are provided a baffle member and a space portion, to thereby equalize the volume quantities and temperatures of exhaust gas flows flowing into these devices. Further, the fuel is atomized into fine particles by injection into pressurized air and the obtained mixture is uniformly mixed into the exhaust gas, so that there are uniformly raised the temperatures of exhaust gas streams into the black smoke eliminating device.

Abstract: An exhaust gas treatment method for an exhaust system that includes a hydrocarbon trap (16) disposed upstream of a downstream catalyst zone comprising a catalyst effective at least for the oxidation of unburned hydrocarbons, in which air is added to the exhaust gas stream in an amount that provides a stoichiometric air/fuel balance in the exhaust gas entering the downstream catalyst zone. The air may be added at any point upstream of the downstream catalyst zone, but optimum results are obtained when air is added between the trap (16) and the downstream catalyst zone. The addition of air can be controlled by the output of a sensor (26) that measures the air/fuel ratio of the exhaust gas, disposed downstream of the trap (16), or by the output of a thermocouple (18) disposed upstream of the trap.

Abstract: An exhaust emission control apparatus for a general-purpose internal combustion engine comprises an exhaust passage allowing passage of an exhaust gas therethrough and having a ternary catalyst, and an air pump for supplying a secondary air to the exhaust passage. The air pump is driven by rotation of a camshaft having a cam for opening and closing an exhaust or intake valve of the internal combustion engine. The drive of the air pump is effected by a pump rocker arm disposed between the cam and a pump shaft of the air pump.

Abstract: A device for purifying exhaust gas includes an HC adsorbent and an exhaust gas purifying catalyst disposed in an exhaust gas passage in this order from the upstream side. The exhaust gas purifying catalyst is provided with an O.sub.2 storage capability, i.e., the exhaust gas purifying catalyst is capable of absorbing oxygen in the exhaust gas when the air-fuel ratio of the exhaust gas is lean, and is capable of releasing the absorbed oxygen when the air-fuel ratio of the exhaust gas becomes rich. When the engine starts, the HC adsorbent adsorbs HC in the exhaust gas. When the temperature of the exhaust gas becomes high, the HC adsorbent releases the adsorbed HC. The device also includes an engine control unit which operates the engine at a lean air-fuel ratio during a predetermined period before the releasing of the HC from the HC adsorbent occurs. Therefore, oxygen is absorbed and stored in the exhaust gas purifying catalyst before the releasing of HC occurs.

Abstract: A method and a device for decomposing nitrogen oxides in an exhaust gas of an internal combustion engine, include feeding the exhaust gas and a reactant which is sprayed into the exhaust gas through the use of compressed air, to a catalytic converter. A compressor for supplying compressed air is associated with the internal combustion engine, and part of the compressed air is diverted and used as the compressed air for injecting the reactant. The sprayed reactant is fed to the catalytic converter, together with the exhaust gas to be purified, which ensures the decomposition of the nitrogen oxides, in particular according to the method of selective catalytic reaction.

Abstract: An exhaust apparatus for a combustion engine having a combustion chamber and an exhaust pipe for conveying exhaust gas in an exhaust stream from the combustion chamber is disclosed, wherein the exhaust apparatus includes a fan member disposed downstream of the combustion chamber and substantially sealingly associated with the exhaust pipe and an air inlet for introducing air relative to the fan member whereby the fan member is driven by the exhaust stream and air so as to create an area of low pressure between the fan member and the combustion chamber whereby extraction of exhaust gas from the combustion chamber is facilitated.

Abstract: A system for purifying an exhaust gas for use in an automobile is disclosed which does not externally discharge unburnt hydrocarbons until a catalyst becomes active. An adsorbent is provided upstream of the catalyst. A heat exchanger is disposed between an upstream portion of the adsorbent and a portion between the adsorbent and the catalyst for controlling the elevation of the temperature of the adsorbent and for promoting the elevation of the temperature of the catalyst. The unburnt hydrocarbons are absorbed by the adsorbent 4 in the initial period of time from starting of an engine until the catalyst 8 becomes active. Temperature control is made in such a manner that the unburnt hydrocarbons which are adsorbed by the adsorbent 4 begins to be desorbed therefrom substantially simultaneously with the time when the catalyst 8 begins to function.

Abstract: A modified in-line adsorber system capable of meeting the California ultra-low emission vehicle (ULEV) standard using a combination of burn-off catalyst and a modified adsorber constructed with an open flow region of substantially unobstructed flow having a hole or a region of larger cell openings to increase the amount and rate of contact between the exhaust gas and the burn-off catalyst, and thereby reduce the light-off time of the burn-off catalyst. For best effect, the open flow region of the adsorber is positioned along the exhaust stream between the engine and the burn-off catalyst as defined by the exhaust flow path of least resistance.

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.

Abstract: An improved system for the control of combustion engine exhaust from a motor vehicle includes an adsorber for the adsorption of hydrocarbons concentrated in the exhaust stream at engine startup, the adsorber being of honeycomb shape which includes a peripheral channeled portion and a central channeled portion, the latter including an exhaust gas by-pass port parallel with the channels, with the through-channels in the central portion of the honeycomb having a relatively high resistance to exhaust gas flow compared to the channels traversing the peripheral portion. Systems with reduced secondary air requirements and providing more efficient burn-off of the adsorbed hydrocarbons are also disclosed.

Abstract: The present invention is an exhaust emission control device for a diesel engine that is small and simple, and can efficiently reduce and eliminate NO.sub.x in exhaust gas. To this end, the device includes a reforming catalyst (12) for reforming either a mixture of diesel fuel and water, or a mixture of diesel fuel, water, and air to an oxygen-containing compound and for supplying the same into an exhaust pipe (2); and a NO.sub.x catalyst (3) is disposed in the exhaust pipe (2), at a position downstream from the supplying position, for reducing and controlling NO.sub.x in the exhaust gas from the diesel engine.

Abstract: The invention is directed at an exhaust system exhibiting an increased flow uniformity under diversion conditions comprising: (1) a honeycomb structure having an inlet and outlet end disposed in a housing located in an exhaust gas stream and downstream from an engine, and having a first substantially unobstructed flow region, and a second more obstructed flow region adjacent the first region, both providing a flow path for the exhaust gases in the exhaust gas stream; and, (2) a fluidics apparatus disposed in the exhaust stream comprising a diverter body located proximate to the first region, a diversion fluid source, a conduit for directing the diversion fluid toward the diverter body and an exhaust flow divergent device.

Abstract: The invention relates to a system for reducing emissions in catalytic converter exhaust systems for an internal combustion engine. The invention comprises air-fuel mixture forming means for providing a mixture of air-fuel to the engine, a catalytic converter for purifying an exhaust gas mixture from the engine, and a control unit adapted for controlling the mixture forming means so that an excess of hydrogen is generated in the exhaust gas mixture during the start-up of the engine. According to the invention, the excess of hydrogen is maintained essentially unburnt within the catalytic converter so as to provide a short light-off time for the catalytic converter.

Abstract: An improved and easily adaptable system to provide secondary air for an internal combustion engine, including a single-cylinder engine unit having (i) a closed crankcase capable of experiencing pressure pulsations produced by the reciprocating motion of a piston in a cylinder, (ii) in the case of a four-cycle engine, a crankcase breather system including a breather assembly attached to a chamber integrally formed with the engine block, or, in the case of a two-cycle engine, an intake reed plate attached to the intake port of the engine, and (iii) an exhaust system including a catalytic converter. The secondary air supply system consists of an external secondary air pump, such as a diaphragm pump, as disclosed in U.S. Pat. No.

Abstract: In an arrangement for controlling the charging air flow of a supercharged internal combustion engine which has an intake air pipe with a throttle valve connected to the discharge side of a supercharger and a communication pipe extending from the intake air pipe to the engine exhaust manifold for supplying air to the engine exhaust gas, an air supply pipe extends from an air filter housing to the supercharger suction side and a return air duct including a flow control valve extends from the intake air pipe to the air filter housing for recirculating air to the supercharger suction side through the air filter housing under the control of the flow control valve for controlling the air pressure in the engine intake air pipe.

Abstract: A shut-off valve unit for a circuit for injecting air into an exhaust system of an internal combustion engine has a casing (9, 29) with a first chamber (10), a second chamber (24) and a third chamber (27). The valve rod (18) forms a passage (43) for communicating air between the first chamber (10) and the second chamber (24). The opening and closing of valve (19) with respect to valve seat (21) is controlled by movement of the membrane (12); which also controls communication between the second chamber (24) and the third chamber (27).

Abstract: In a system for treating an exhaust stream, such as the exhaust of an internal combustion engine (10), the exhaust is initially treated by a first catalytic converter (14) and its effluent is cooled in an indirect heat exchanger (18) with an extraneous coolant fluid, i.e., one other than recycled engine exhaust, before introducing the exhaust into a hydrocarbon trap (30) to adsorb hydrocarbons therefrom at least during a cold-start period of engine operation. Such cooling enables utilization of highly efficient adsorbent materials such as activated carbon which otherwise could not be used. Adsorbed hydrocarbons are desorbed from the hydrocarbon trap (30) as the engine exhaust heats up. The exhaust is passed from hydrocarbon trap (30) to a second catalytic converter (34) for oxidation of the hydrocarbons.

Abstract: The present invention is a flow focusing and mixing device for use with internal combustion engines. The flow focusing and mixing device may be located in the exhaust stream of an internal combustion engine for increased oxidization of the exhaust, increasing the air quality of the exhaust released into the environment.

Abstract: An apparatus for producing a fresh air stream, has a blower connectable at a pressure side with an exhaust gas conduit of an internal combustion engine of a motor vehicle, a fresh air supply element communicatable with the exhaust gas conduit, a check valve provided between the blower and an opening of the fresh air supply element into the exhaust gas conduit, a cut-off arranged in the fresh air supply element between the check valve and its opening into the exhaust gas conduit and having a closing member loaded with a spring force toward a closing position, an actuating member for the closing member, and a bypass branching from the fresh air supply element so that a pressure which builds when the blower operates and is supplied through the bypass to the actuating member for the closing member acts opposite to the spring force.

Abstract: An internal combustion engine has a temperature-dependent exhaust gas converter arranged to receive a secondary air supply from a secondary air pump, and the engine has a fuel vapor accumulator to collect fuel vapors from the fuel supply for the engine. During cold-starting of the engine, the air pump is operated to draw fuel vapors from the accumulator into the secondary air supply to regenerate the accumulator and provide a flammable secondary air-fuel mixture to the exhaust gas converter.

Abstract: An exhaust apparatus for a combustion engine having a combustion chamber and an exhaust pipe for conveying exhaust gas in an exhaust stream from the combustion chamber wherein the exhaust apparatus includes a fan member disposed within the exhaust pipe and driven by the exhaust stream so as to create an area of low pressure between the fan member and the combustion chamber whereby extraction of exhaust gas from the combustion chamber is facilitated.

Abstract: An internal combustion engine 12 in which liquid fuel is introduced prior to the charge entering the combustion chambers is mounted in a vehicle having an air scoop 34 which acts as a source of ram air pressurised by the movement of the vehicle. The ram air is fed into the exhaust system by way of an isolation valve 36 which is opened only during engine deceleration modes and serves to reduce emissions of unburnt hydrocarbons and carbon monoxide caused by the fuel wetting the intake manifold.

Abstract: Device for injecting air into an exhaust system fitted with catalytic cleaner for a supercharged Otto engine, in whose intake manifold is incorporated a motor driven air compressor operating with internal compression, giving rise to the supercharging. An air bleeding duct is arranged for adjustable air bleeding from the constriction zone of the air compressor to supply this air as additional air to the catalytic cleaner. This air bleeding duct extends from a point in the constriction zone to a point in the exhaust system upstream from the catalytic cleaner. In an inlet section of the intake manifold, located upstream from the compressor, is installed an electronically controlled device for engine idle control during bleeding of the air via the air bleeding duct.

Abstract: A device for injecting air into an exhaust system fitted with catalytic cleaner for a supercharged Otto engine, in whose intake manifold is incorporated an air compressor driven by the engine, which compressor causes the supercharging. An air bleeding duct is arranged for adjustable bleeding of air from the intake manifold and to supply this air as additional air to the catalytic cleaner. This air bleeding duct extends from a point in the intake manifold downstream from the compressor to a point in the exhaust system upstream from the catalytic cleaner. In an inlet section of the intake manifold, located upstream from the compressor, there is an electronically controlled device for idle control of the engine as the air is bled via the air bleeding duct.

Abstract: A method is described for reducing the total emissions during cold starts from an engine burning a hydrocarbon fuel and having an afterburner arranged upstream of a catalytic converter. The method comprises the steps of:(i) adding an excess of fuel to the engine combustible charge and adding air to the engine exhaust gases immediately after the engine has first fired to assure the presence in the exhaust/air mixture of sufficient concentrations of hydrogen and oxygen to permit the resulting exhaust/air mixture to be ignitable and to burn with a steady flame in the afterburner while the latter is at a temperature close to the ambient temperature, and(ii) igniting the exhaust/air mixture in the afterburner immediately after the engine has first fired.

Abstract: Disclosed herein is a marine propulsion device comprising a combustion chamber, an exhaust passage, an air pump and a three-way catalytic converter. The air pump pumps air into the exhaust passage at or immediately upstream of the catalytic converter. By this construction the internal combustion engine can be run slightly rich, but the catalytic converter will see a close to stoichiometric mixture so that the pollutants in the exhaust stream can be oxidized or reduced appropriately since the catalytic converter will be able to operate as a three-way catalytic converter.

Abstract: Disclosed herein is an outboard motor comprising a drive shaft housing including an inner wall partially defining a pumping chamber, an air inlet port communicating between the pumping chamber and the atmosphere, and an air outlet port communicating with the pumping chamber, a propeller shaft rotatably supported by the drive shaft housing, an engine mounted on the drive shaft housing, a drive shaft drivingly connecting the engine to the propeller shaft, a closure member which is supported by the drive shaft housing, which partially defines the pumping chamber, and which rotatably supports the drive shaft, an exhaust passageway communicating with the engine, a catalytic converter located in the exhaust passageway and communicating with the outlet port, and an impeller located in the pumping chamber, mounted on the drive shaft for rotation therewith, and operative to supply air to the catalytic converter.

Abstract: An apparatus for monitoring a system for delivering secondary air to an exhaust tube of an internal combustion engine. In the method and apparatus, a secondary air pump is switched on and builds up a pressure on the inlet side of a blocking valve which is normally closed and not being acted upon. The blocking valve has a valve closing member that is acted upon by a predetermined closing force of an elastic element. If the secondary air quantity pumped by the secondary air pump reaches a certain minimum air quantity and pressure, then with the then-opened blocking valve, a lambda sensor disposed in an exhaust tube detects a change in the lambda value in the exhaust tube that exceeds a predetermined threshold value. The apparatus is suitable for monitoring the function of a system for delivering secondary air to the exhaust tube of an internal combustion engine.