Abstract:
High exhaust gas temperatures whereby sulfur is removed from a lean NOx traps simultaneously with regeneration of a Diesel particulate filter is provided by alternating engine operation in respectively defined lean and rich combustion modes. The duration and frequency of the respective lean and rich operating modes, as well as the air/fuel ratio during the respective modes, are preferably controlled by the sensed temperature of the lean NOx trap substrate.
Abstract:
A method is disclosed for controlling the air-fuel ratio in a four-stroke gasoline direct-injection controlled auto-ignition combustion. The engine is operated with two sequential pairs of expansion and contraction strokes during two revolutions of the engine crank, the two revolutions defining a combustion cycle. A system is employed for variably actuating the intake and exhaust valves and adjusting the flow of air and burned gases entering the combustion chamber. Adjusting the flow affects the resulting air-fuel ratio in the combustion chamber. The valve actuating system is employable to operate the intake and exhaust valves with an exhaust re-compression or an exhaust re-breathing valve strategy. Either valve strategy affects the air-fuel ratio in the cylinder and causes a proportion of burned gases from previous combustion cycles to be retained in the cylinder to provide the necessary conditions for auto-ignition of the air-fuel mixture.
Abstract:
The present invention relates to an internal combustion engine comprising: a plurality of combustion chambers (41,42,43,44);an air induction system (45,45A,45B,46,47)for delivering air to each combustion chamber (41,42,43,44);a fuel system for delivering fuel to each combustion chamber (41,42,43,44); an exhaust system (48,50) for relaying combusted gases from the combustion chambers (41,42,43,44) to atmosphere; and an exhaust recirculation system (49,51) to relay combusted gases from the exhaust system (48,50) to at least one of the combustion chambers (42,43). The engine has a chamber deactivation operating mode in which at least one combustion chamber (41,44) is active and receives fuel and air which are combusted therein and at least one other combustion chamber (42,43) is deactivated and is supplied with no fuel by the fuel system. In the chamber deactivation operating mode the exhaust gas recirculation system (49,51) supplies combusted gas to the (or each) deactivated combustion chamber (42,43).
Abstract:
A method of operating a four-stroke gasoline direct-injection controlled auto-ignition combustion engine includes opening both the intake and exhaust valves during terminal portions of the expansion strokes and initial portions of the contraction strokes, injecting fuel directly into the combustion chamber for mixing with retained gases and igniting the fuel near the ends of the contraction strokes. In the process, combustion gases are expanded to produce power during mayor portions of the expansion strokes, combusted gases are blown down into the exhaust outlet and the air inlet and are partially redrawn into the cylinder with fresh air during the terminal portions of the expansion strokes so the air charges are heated by the hot exhaust gases. Portions of the charges re-expelled and the remaining portions of the charges and injected fuel are compressed for ignition of the dilute fuel/ air and exhaust gas mixture. Substantial reductions of NOx emissions result from the method.
Abstract:
A method is disclosed for controlling the air-fuel ratio in a four-stroke gasoline direct-injection controlled auto-ignition combustion. The engine is operated with two sequential pairs of expansion and contraction strokes during two revolutions of the engine crank, the two revolutions defining a combustion cycle. A system is employed for variably actuating the intake and exhaust valves and adjusting the flow of air and burned gases entering the combustion chamber. Adjusting the flow affects the resulting air-fuel ratio in the combustion chamber. The valve actuating system is employable to operate the intake and exhaust valves with an exhaust re-compression or an exhaust re-breathing valve strategy. Either valve strategy affects the air-fuel ratio in the cylinder and causes a proportion of burned gases from previous combustion cycles to be retained in the cylinder to provide the necessary conditions for auto-ignition of the air-fuel mixture.
Abstract:
A compression ignition engine (20) has a control system (26) for processing data, one or more combustion chambers (22), and fuel injectors (24) for injecting fuel into the chambers (22). The control system (26) controls fueling using a result of the processing of certain data, such as engine speed and engine load, to select one of three fueling modes (HCCI, HCCI+CD, CD) for operating the engine (20). When the result of the processing selects the HCCI mode, the engine (20) is fueled to cause homogeneous-charge compression-ignition (HCCI) combustion in all combustion chambers (22). When the result of the processing selects the HCCI+CD mode, the engine (20) is fueled to cause HCCI combustion in some chambers (22) and CD (conventional diesel) combustion in the remaining chambers (22). When the result of the processing selects the CD mode, the engine (22) is fueled to cause CD combustion in all chambers (22).
Abstract:
Bei einem Verfahren zur Regelung des Kompressionszündbetriebes einer Hubkolbenbrennkraftmaschine (1) mit mehreren Zylindern (2 1-4 ), in denen ein Kraftstoff-/Luftgemisch verbrannt wird, wird ein Ist-Wert wenigstens einer vom Vorgang der Kraftstoffverbrennung beeinflußten Kenngröße (13) erfaßt und mit einem vorgebbaren Sollwert (15) verglichen zur Bildung einer Stellgröße (12), mit der die Einstellung eines auf die Gemischbildung wirkenden Betriebsparameters zum Angleich des Ist-Wertes der Kenngröße (13) an den Sollwert (15) nachgeführt wird. Um eine stabile Verbrennung im Kompressionszündbetrieb einer mehrzylindrigen Brennkraftmaschine zu gewährleisten, ist vorgesehen, in einem ersten Regelkreis (20) einen von allen Zylindern (2 1-4 ) beeinflußten Mittelwert einer Kenngröße (13) zu erfassen und mit einer allen Zylindern zugeführten Stellgröße (12) auf allen Global-Sollwert zu regeln und in einem zweiten Regelkreis an jedem Zylinder erfaßte Kenngrößen durch individuell ermittelte Stellgrößen (12) einander anzugleichen.
Abstract:
An internal combustion cylinder assembly includes a cylinder having a cylinder head at an end thereof, a combustion chamber disposed in the cylinder head, a piston disposed slidably within the cylinder, the piston having a bottom dead center position distal from the combustion chamber and a top dead center position proximate to the combustion chamber, a pilot quantity of fuel disposed substantially dispersably within the cylinder, a working fluid disposed compressably within the cylinder, the piston compressing the working fluid and the pilot quantity of fuel as it slides from the bottom dead center position to the top dead center position, and wherein the pilot quantity of fuel is substantially a maximum quantity that will not support auto-ignition when the working fluid and the pilot quantity of fuel have been compressed.