A converter containing a NOx absorbing and reducing catalyst is disposed in the exhaust passage of an internal combustion engine. The upstream half portion (portion of the inlet side) of the substrate of the NOx absorbing and reducing catalyst in the converter carries the oxygen storage component that absorbs oxygen in the exhaust gas when the air-fuel ratio of the exhaust gas is lean and releases the absorbed oxygen when the air-fuel ratio of the exhaust gas flowing in is rich in addition to carrying the NOx absorbing and reducing catalyst. After NOx is absorbed by the NOx absorbing and reducing catalyst as a result of operating the engine at a lean air-fuel ratio, the engine is operated at a rich air-fuel ratio, so that NOx is released from the NOx absorbing and reducing catalyst and is purified by reduction. Here, oxygen is released from the oxygen storage component carried by the upstream half portion of the substrate and is reacted with the H 2 and CO components in the exhaust gas, so that the temperature of the NOx absorbing and reducing catalyst is raised within short periods of time due to the heat of reaction. Therefore, the catalyst exhibits increased activity and the NOx absorbing and reducing catalyst exhibits improved NOx purification capability.

Exhaust gas purification device for an internal combustion engine

A method is presented for estimating an amount of ammonia stored in a urea-based SCR catalyst based on a dynamic model of the catalyst. The model takes into account chemical and physical properties of the catalyst, such as catalyst volume, the number of available ammonia storage cites, adsorption and desorption dynamics, as well as poisoning, thermal aging, and different catalyst operating temperatures, and generates the estimate based on a measured or estimated amount of NOx in an exhaust gas mixture upstream of the catalyst, an amount of reductant injected into the catalyst to facilitate NOx reduction, and on a measured value of NOx in an exhaust gas mixture downstream of the catalyst. The estimated ammonia storage amount is then used to control the amount of reductant injected into the catalyst to maintain desired ammonia storage amount such that maximum NOx conversion efficiency coupled with minimum ammonia slip are achieved.

Exhaust gas aftertreatment systems

An air-fuel ratio control system for an internal combustion engine includes a LAF sensor and an O2 sensor arranged in an exhaust pipe at respective locations upstream and downstream of a catalytic converter. A desired air-fuel ratio coefficient used in calculating an amount of fuel supplied to the engine is calculated based on operating conditions of the engine, and corrected based on output from the O2 sensor. The air-fuel ratio of a mixture supplied to the engine is feedback-controlled to a stoichiometric air-fuel ratio based on the corrected desired air-fuel ratio coefficient. When the output from the O2 sensor falls within a predetermined range, the desired air-fuel ratio coefficient is not corrected, but held at an immediately preceding value thereof.

Air-fuel ratio control system for internal combustion engines

The invention relates to a fuel-injection valve, in particular a high-pressure injection valve for directly injecting fuel into a combustion chamber of a compressed-mixture, spark-ignition internal combustion engine. Said valve is characterised in that an outlet opening (23) is provided downstream of the valve seat (20), the downstream end of said opening having a slit-forming element (30) that to a great extent closes the outlet opening (23). A slit-type flow outlet (35), through which a fuel spray can be discharged in a fan-type jet, is formed between the slit-forming element (30) and a front face (34) of the valve seat body (16).

Fuel-injection valve

An internal combustion engine comprises an intake tract in which a throttle valve is disposed. The engine also comprises a camshaft which acts on gas inlet valves associated with respective cylinders. A phase-adjustment device is used to adjust a phase between the camshaft and a crankshaft. A desired air mass flow in a combustion chamber of the cylinder is determined depending on a charge requirement requested by the driver. The desired air mass flow is adjusted by varying the phase between the camshaft and the crankshaft if the desired air mass flow can be adjusted by varying the phase while substantially maintaining an actual pressure difference upstream and downstream of the throttle valve. Otherwise, the desired air mass flow is adjusted by varying the opening angle of the throttle valve.

Method and device for controlling an internal combustion engine

The fuel feed system has a tank, two fuel pumps (6,12) and at least one valve. The first pump brings the fuel from the tank to a supply pipe (10) and the second pump delivers it from here to the injector where it can enter the combustion chamber indirectly. A valve (30) influencing the feed pressure in the supply pipe changes this pressure as a function of engine conditions. It acts electrically and possesses a flow resistance. It is located in another pipe (22) between the tank and the supply pipe. Along with this valve is a pressure control valve (26) in series.

Fuel supply system for IC engine

The invention sets forth an arrangement for the aftertreatment of exhaust gases from a compression-ignition internal combustion engine, in which, to improve the operation of a reducing catalytic converter, a reducing agent is injected into the exhaust gas fed to the catalytic converter. Injection is performed by virtue of an electrically controlled metering valve which is combined in a common housing with a control valve. This control valve serves for the controlled introduction of compressed air supplied, in which a quantity of reducing agent made ready by the metering valve is prepared and introduced intermittently into the exhaust gas. This serves, in particular, to avoid urea deposition and clogging in the metering valve and the control valve and for the optimum preparation of the reducing agent introduced.

Arrangement for the aftertreatment of exhaust gases

Investigation into the Formation and Prevention of Internal Diesel Injector Deposits

A fuel supply system with two series-connected pumps and fuel injection valves that inject fuel directly into a combustion chamber of an engine. The system includes a relief device. In a simple embodiment, the relief device can assure that the pressure in the pressure line can drop when the engine has been shutoff. The relief line may, however, also be embodied such that during the entire time of engine operation, the pressure in the pressure line can be lowered at any time as needed. The apparatus and the method are intended for an internal combustion engine of a vehicle.

Fuel supply system and method for operating an internal combustion engine

A fuel supply systems with two series-connected pumps and with fuel injection valves that inject fuel directly into a combustion chamber of an engine in which a starting process takes less time because of the small feed quantity of the second fuel pump The system includes a valve device which assures that during the starting process the first fuel pump furnishes the fuel to the fuel valves at elevated feed pressure In many cases, this elevated feed pressure suffices to start the engine in the quickest possible time The apparatus and the method are intended for an internal combustion engine of a vehicle

Heinz Stutzenberger

Papers

Fuel supply system for IC engine

Arrangement for the aftertreatment of exhaust gases

Investigation into the Formation and Prevention of Internal Diesel Injector Deposits

Fuel supply system and method for operating an internal combustion engine

Fuel supply and method for operating an internal combustion engine