Abstract: A valve assembly is adapted to be disposed in an automotive engine exhaust system at an outlet of an internal combustion engine. The assembly includes a valve body having an opening therethrough including an inlet portion and an outlet portion. A first valve and a second valve are disposed in the opening intermediate the inlet and outlet portions. The first and second valves have an open position and a closed position. The first valve blocks a first predetermined amount of the opening when in the closed position. The second valve blocks a second predetermined amount of the opening when in the closed position, with the second predetermined amount being less than the first predetermined amount. An actuator is connected to the first valve and the second valve and is operable to selectively move each of the valves between respective the open positions and the closed positions.

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: An exhaust cleaning device of an internal combustion engine includes a particulate filter disposed in an exhaust duct of the internal combustion engine. A regeneration control increases the temperature of the particulate filter to approximately a predetermined target temperature but the amount of the temperature increase controllably corrected by the regeneration control.

Abstract: A method and system providing a vehicle condition detection means (38C) for detecting the stopped and traveling state of a vehicle, and when the vehicle condition detection means (38C) detects that the vehicle has stopped during operation of an exhaust gas temperature raising means (351C), closing an exhaust gas throttling valve (16) in addition to continuing the operation of the exhaust gas temperature raising means (351C), and subsequently, when the vehicle's traveling state is detected, opening the exhaust gas throttling valve (16) and continuing the operation of the exhaust gas temperature raising means (351C).

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: A turbocharged engine control system is provided that comprises an exhaust gas after-treatment system and a variable-capacity turbocharger. The turbocharged engine control system is configured to estimate a clogging ratio of the exhaust gas after-treatment system based on an equivalent surface area of the exhaust gas after-treatment system. A correction value is determined based on a turbine outlet pressure and the correction value is added to the clogging ratio. A target nozzle opening value is corrected such that the nozzle opening value increases as the exhaust gas after-treatment system becomes more clogged. Consequently, as the exhaust gas after-treatment system becomes clogged, the increase in pressure on the inlet side of the exhaust turbine (which acts as back pressure with respect to the engine) is suppressed and the increase in the internal EGR ratio caused by residual gas is also suppressed.

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: The recycling timing schedule for a diesel particulate filter (DPF) can be easily and accurately determined. There is a differential pressure sensor that detects differential pressure &Dgr;P in the DPF, and an airflow meter that detects the flow velocity v in an exhaust path. An ECU calculates the quantity of deposited fine exhaust particles ML according to: ML=[&Dgr;P−(A&mgr;v+C&rgr;v2)]/(B&mgr;v+D&rgr;v2) Recycling of the filter is determined according to a determination formula used to compare the calculated deposited quantity ML to a reference quantity. In this way, the deposited quantity can be accurately obtained without using a map.

Abstract: The method of treating a fuel lean exhaust containing NOX and SO2 includes splitting the exhaust into major and minor portions for flow through multiple flow paths each of which contains a particulate trap and an absorber containing a NOX oxidation catalyst and a nitrate absorbent. The major portion is passed through a flow path in the lean state at a first temperature to convert the NOX to nitrate and the SO2 to sulfate. After the first period of operation flows are switched so that one flow path receives a minor exhaust portion for a second period of time during which fuel is injected into that flow path along with diversion of a portion of exhaust from another flow path through a bypass.

Abstract: An exhaust system (16) of a diesel engine (10) has a diesel particulate filter (18) for treating exhaust gas. When trapped soot has accumulated to an extent that may affect performance of the filter, an engine control system (12) forces combustion of trapped soot by increasing exhaust back-pressure using a control device (20) such as a back-pressure control valve or vanes of a variable geometry turbocharger.

Abstract: An exhaust gas purification system includes a particulate filter, a sensor that detects a filter differential pressure and a controller that controls regeneration of the particulate filter. The controller is programmed to execute a control for burning particulate accumulated on the particulate filter, determine whether regeneration of the particulate filter is completed, detect, in cooperation with the sensor, a filter differential pressure immediately after it is determined that regeneration of the particulate filter is completed, and estimate an ash accumulation amount based on the detected filter differential pressure. An exhaust gas purification method is also provided.

Abstract: A temperature estimating apparatus for an internal combustion engine is provided for correctly calculating the temperature of an exhaust device even when the internal combustion engine is started under low temperature conditions. The temperature estimating apparatus comprises an ECU for estimating the temperature of a hydrocarbon adsorbent in an exhaust system of the internal combustion engine through calculations. The ECU calculates an estimated adsorbent temperature of the adsorbent in accordance with an engine rotational speed, an absolute intake pipe inner pressure, an engine water temperature, an intake temperature, and a detected humidity of exhaust gases. This calculation is started when condensation, which has occurred within an intake pipe, is eliminated.

Abstract: EGR mass fraction or a value indicative thereof can be calculated based on temperature measurements rather than mass flow and/or pressure measurements, hence negating the need for expensive and relatively unreliable measurement devices in an active EGR system for an internal combustion engine. The EGR system may be a low pressure EGR system configured to direct cooled, filtered EGR to the engine's air intake system using an effective, simple venturi and/or a continuously regenerated catalytic particulate trap. The resultant system can reduce NOx emissions in a diesel engine on the order of 50% and approximately 90% for CO, HC, and PM. NOx and other emissions can be reduced still further when the EGR system is combined with other pretreatment and/or after treatment devices. Many components of the low pressure EGR system are also usable in a passive EGR system.

Abstract: An engine control unit of an exhaust gas purification system of an internal combustion engine measures a pressure difference between an upstream and a downstream of a diesel particulate filter (DPF) after heating the DPF at least to a predetermined temperature and maintaining the DPF at the temperature for a while. The DPF is disposed in an exhaust pipe of the engine. A soluble organic fraction included in particulate matters in exhaust gas can be eliminated at the predetermined temperature. The ECU calculates a quantity of the particulate matters trapped by the DPF from the measured pressure difference. Thus, the quantity of the trapped particulate matters is calculated precisely, independently of a composition of the particulate matters or a state of the soluble organic fraction.

Abstract: An exhaust gas dilution apparatus 10-2 is the same form multi-venturi type comprising a rectifier 11, divider 12, exhaust chamber 14, dilution tunnel 15, and a divider pipes 13t on the dilution side of a tunnel 15 side. All divider pipes 13 are provided with a venturi 21 having the same performance inserted in the same position, to measure the flow rate in the dilution tunnel and the flow rate on the exhaust pipe side. The opening of the shutter 19 provided in the exit of the exhaust chamber 14 is controlled so that the two flow rates are equivalent.

Abstract: The recycling timing schedule for a diesel particulate filter (DPF) can be easily and accurately determined. There is a differential pressure sensor that detects differential pressure &Dgr;P in the DPF, and an airflow meter that detects the flow velocity v in an exhaust path.

Abstract: A method and a device for controlling an internal combustion engine having an exhaust gas aftertreatment system are described. A quantity (B) which characterizes the state of the exhaust gas aftertreatment system is determined based on at least one characteristic operating quantity of the internal combustion engine.

Abstract: A method of agglomerating particulate matter in exhaust gas from an engine is provided. The method includes dividing a flow of exhaust gas from the engine into at least two streams of exhaust gas. Each of the two streams of exhaust gas include particulate matter. At least one characteristic of the particulate matter in at least one of the two streams of exhaust gas is altered. The two streams of exhaust gas are combined so that the particulate matter agglomerates into larger particles.

Abstract: An exhaust passage (20) of an internal-combustion engine (1) is provided with exhaust emission control means (40) capable of reducing harmful substances in exhaust gas under a given exhaust pressure condition and an exhaust sensor (22) for detecting the concentration of a specific exhaust component (H2, O2) in the exhaust gas, and performance lowering identifying means identifies lowering of the performance of the exhaust emission control means (40) by detecting a failure to fulfill the given exhaust pressure condition in accordance with the output of the exhaust sensor.

Abstract: A failure determination device that detects the humidity of exhaust gases from an internal combustion engine and a control system for an exhaust passage changeover valve, which can switch the changeover valve with appropriate timing, thereby enabling sufficient purification of exhaust gases. An operating condition of the engine is detected. Based on the detected operating condition of the engine, it is determined whether the engine is in an operating condition in which failure determination of the humidity sensor can be executed. It is determined whether the humidity sensor has failed, based on a result of detection by the humidity sensor, when it has been judged that the failure determination of the humidity sensor can be executed.

Abstract: In order to prevent that a liquid reducing agent in a selective catalytic reduction system freezes, there are provided additional resistor heating elements on the pressure sensor diaphragm of the pressure sensor that is present in the reducing agent feed system. The same technique is applied in the production of the heating sensors as in the production of the sensor resistance network. The use of the sensor diaphragm surface for the electrical heating of the liquid reducing agent (e.g., aqueous urea solution) eliminates the need for additional installation space, sealed areas, and connectors for the electrical supply and triggering mechanism.

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 device for purifying the exhaust gas of an internal combustion engine is disclosed. The device comprises a particulate trap disposed in the engine exhaust system, an exhaust gas recirculation passage communicating the upstream of the particulate trap in the engine exhaust system with the engine intake system, a control valve for controlling the amount of exhaust gas recirculated through the exhaust gas recirculation passage to be an optimum amount in accordance with an engine operating condition. In the device, an amount of the fresh air introduced into the engine intake system during a fuel-cut is detected, and an amount of particulate trapped by the particulate trap is estimated on the basis of the amount of fresh air detected after the control valve is opened to a predetermined opening degree.

Abstract: An exhaust gas purifying apparatus for an internal combustion engine is provided for simultaneously realizing sufficient recovery of the adsorbing capability of an adsorbent and limitation to an increase in exhaust resistance. The exhaust gas purifying apparatus for an internal combustion engine comprises a flow path switching valve for switching an exhaust gas flow path to a bypass exhaust passage or to a main exhaust passage, three-way catalysts, and an HC adsorbent arranged in the bypass exhaust passage for adsorbing hydrocarbons in exhaust gases and fully desorbing the adsorbed hydrocarbons when it is heated to a full desorption temperature or higher. A troidal passage of the main exhaust passage completely surrounds a portion of the bypass exhaust passage in which the HC adsorbent is arranged. A ratio S1/S2 of the cross-sectional area S2 of the troidal passage to the cross-sectional area of a flow-in passage is set in a range from 1.

Abstract: An emission control apparatus for an internal combustion engine has a bypass passage bypassing a portion of a main exhaust passage located upstream of an exhaust gas-purifying catalyst device, an adsorbent provided in the bypass passage, a passage switching device for switching between flow of exhaust gas to the bypass passage and flow of exhaust gas to the main exhaust passage, and a bypass flow control device for adjusting a flow that occurs through the bypass passage when the unburned gas component is desorbed (released) from the adsorbent so that the flow through the bypass passage becomes equal to or less than a predetermined flow and assumes a proportion that is equal to or less than a predetermined proportion relative to the flow through the main exhaust passage.

Abstract: In a diesel particulate filtering device 1A, 1B which is provided with a diesel particulate filter units 10, 20, 30 for cleaning exhaust gas, and in which cleaning of the exhaust gas and the recovery thereof are performed, diesel particulate filter controllers 60, 62 for determining a recovery time based on detected values PI, PO0, PO1, PO2 of exhaust pressure sensors 51 to 55 in an upstream side of said diesel particulate filter units 10, 20, 30 and a downstream side thereof are provided with determination-value update means 60a, 62a resetting determination values R0, R1, R2 for determining a recovery time by comparing said detected values, PO0, PO1, PO2 with a standard exhaust pressure value P0.

Abstract: According to the present invention, there is provided an exhaust gas purification device, comprising a NOx absorbent arranged in an exhaust passage of an engine for absorbing NOx therein when an air-fuel ratio of an exhaust gas flowing into the NOx absorbent is lean, the NOx absorbent discharging NOx absorbed therein when a concentration of the oxygen in the exhaust gas flowing into the NOx absorbent decreases, a trapping element arranged in the exhaust passage upstream of the NOx absorbent for trapping particulates, a processing element for processing the particulates trapped in the trapping element to regenerate the trapping element, and a preventing element for preventing the exhaust gas from flowing into the NOx absorbent from the trapping element when the trapping element is regenerated.

Abstract: A completely self-contained device reduces the NOx content in the exhaust gas of an internal combustion engine operated with excess air. One or more reduction catalytic converters working according to the SCR principle are provided. A reducing agent control unit need not make any recourse to data present in the control unit of the internal combustion engine. Fitting and retrofitting to a vehicle is greatly simplified, particularly for vehicles that are already in use.

Abstract: An exhaust recirculation of gases in internal combustion engines, notably for automobiles, which has a catalytic converter, recycling apparatus for recycling the exhaust gases and heat recovers apparatus for recovering heat from the exhaust gases. A single heat exchanger is arranged for cooling the recycled exhaust gases and recovering the heat energy from the exhaust gases for heating the passenger compartment of the vehicle and for protecting the catalytic converter from excessively high exhaust temperatures. Valves for diverting exhaust gases, a back-pressure valve and an EGR valve are controlled for this purpose by control electronics. The invention is particularly applicable to direct-injection petrol or diesel engines or to lean-mixture petrol engines.

Abstract: Disclosed is a technology of diagnosing an exhaust gas purifying apparatus about a fault in its temperature control function of controlling a temperature of an exhaust gas purifying catalyst. The exhaust gas purifying apparatus for an internal combustion engine includes the exhaust gas purifying catalyst, and a temperature control means for controlling the temperature of this exhaust gas purifying catalyst. The exhaust gas purifying apparatus is judged to be faulted, wherein at least one of a state of the temperature control means and a state of the exhaust gas purifying catalyst serves as a parameter.

Abstract: An exhaust restriction device for an internal combustion engine is disclosed. The exhaust restriction device includes a main valve and a bypass valve for restricting the flow of exhaust gas. The main valve is located in a main passage and may be selectively closed. The bypass valve is located in a bypass passage and is biased into a position closing a port connecting the main passage and the bypass passage. Closing the main valve may cause exhaust back pressure to build against the bypass valve and an actuator therefor until the biasing force is overcome. When the biasing force is surpassed by the exhaust back pressure, the bypass valve opens to relieve the back pressure. The bypass valve closes when back pressure falls below the biasing force. A method of operating the exhaust restriction device is also disclosed.

Abstract: In order to reduce the exhaust gas emissions of automotive vehicle combustion engines including exhaust gas catalytic converters, the exhaust gases are caused to flow between the engine and the catalytic converter through conduit branches of different thermal caracteristics. Said conduit branches comprise a full load tube and a partial load tube, with the full load tube surrounding the partial load tube so as to provide an annular space between the full load tube and the partial load tube.

Abstract: A device for purifying the exhaust gas of an internal combustion engine is disclosed. The device comprises a collision collecting type filter for collecting particulates which is arranged in an exhaust passage, can vary a pressure in the exhaust passage on at least one of the upstream side and downstream side of said filter, determines that the collected particulates have been burned and the filter has been regenerated, and suddenly changes the pressure in the exhaust passage when it is determined that the filter has been regenerated.

Abstract: An exhaust gas purifying device for an engine comprises an exhaust gas purifying catalyst arranged in the exhaust passage. The catalyst is capable of reducing NO.sub.X in the catalyst in the oxidizing atmosphere, and comprises a reducing agent adsorbent adsorbing a reducing agent in the inflowing exhaust gas therein when the pressure in the adsorbent becomes higher, and desorbing the adsorbed reducing agent therefrom when the pressure in the adsorbent becomes lower. An exhaust gas control valve is disposed in the exhaust passage downstream of the catalyst. When both the engine load and the engine speed are low, the opening of the valve is made smaller to increase the pressure in the catalyst. At this time, hydrocarbon is fed to the catalyst, and is then adsorbed in the catalyst. When the engine load or the engine speed becomes high, or the cumulative amount of hydrocarbon fed to the catalyst becomes larger than a predetermined amount, the valve is made fully open to reduce the pressure in the catalyst.

Abstract: A trapper apparatus arranged in the exhaust line of a diesel engine, provided with a pair of transversely separated trapper units and with a valve plate arranged before units for selectively introducing the exhaust gas from the engine into one of the units. The valve plate is further provided with a pair of fuel injection nozzles each of which is adapted for communicating a common fuel inlet with one of the trapper units which is closed by the valve plate.

Abstract: A multistage catalytic reactor for purifying exhaust gas has a passage for communicating exhaust gas to first and second catalyst bed assemblies, and a valve for automatically maintaining flow of the gas solely through the first catalyst bed assembly in response to a first operating condition and for automatically passing the gas through the first and second catalyst bed assemblies in response to a second operating condition, shifting of said valve being free of external control.