Abstract:
A method and system for actuating an internal combustion engine exhaust vaive to provide compression release actuation during an engine braking mode of engine operation and early exhaust valve opening actuation during a positive power mode of engine operation is disclosed. The system may include a first cam having a compression release lobe and an early exhaust valve opening lobe connected to a hydraulic lost motion system including a first rocker arm. A hydraulically actuated piston may be selectively extended from the hydraulic lost motion system to provide the exhaust valve with compression release actuation or early exhaust valve opening actuation. The hydraulicaily actuated piston may be provided as a slave piston in a master-slave piston circuit in a fixed housing, or alternatively, as a hydraulic piston slidably disposed in a rocker arm. The method and system may further provide exhaust gas recirculation and/or brake gas recirculation in combination with compression release actuation and early exhaust valve opening actuation.
Abstract:
Systems for, and methods of, controlling exhaust gas temperature in a multi-cylinder internal combustion engine during positive power operation of the engine are disclosed. Control of exhaust gas temperature may be desired to improve emissions performance in the engine, which is often dependent upon exhaust gas temperature. One or more temperature probes may be used to first determine the actual exhaust gas temperature of the engine while it is operated in a positive power mode. Next, an ECM or similar device may be used to determine a temperature difference between the actual exhaust gas temperature and a desired exhaust gas temperature for emissions performance. Based on the determined temperature difference, one or more cylinders of the engine may continue to be operated in positive power mode while one or more cylinders of the engine are switched to operating in a selected engine braking mode. The operation of some cylinders in positive power mode while operating other cylinders in engine braking mode may cause the actual exhaust gas temperature to change and more closely match the desired exhaust gas temperature.
Abstract:
An engine for use in an air hybrid vehicle comprises at least one cylinder having a piston (20) defining a variable volume working chamber (10) and intake (12, 14) and exhaust (16) valves controlling the flow of air into and out of the working chamber. The cylinder is operable in any one of at least two modes, namely a first mode in which power is generated by burning fuel in the working chamber (10), and a second mode in which the cylinder acts to compress air drawn into the working chamber (10) and to store the compressed air in an air tank (36). The engine further comprises a non-return valve (32) in an intake port leading to an intake valve (12) of the cylinder so as to define an auxiliary chamber (30) in the intake port between the intake valve (12) and the non-return valve (32). A passage (24) connecting the auxiliary chamber (30) to the air tank (36) contains a valve (34) for controlling the flow of compressed air between the auxiliary chamber (30) and the air tank (36). In the invention, a stop (40) is provided which is operative to prevent full closure of the intake valve (12) when the engine is operating in the second mode, whereby the air compressed in the working chamber by the movement of the piston is admitted through the open intake valve (12) into the auxiliary chamber (30).
Abstract:
Ein Verfahren zum Erzeugen von Druckluft und Einblasen derselben bei einer Verbrennungskraftmaschine (2), insbesondere eines Dieselmotors, mit einem Abgasturbolader (3), weist folgende Verfahrensschritte auf: Ermitteln von Betriebsparametem der Verbrennungskraftmaschine (2) zum Bestimmen von Betriebszuständen der Verbrennungskraftmaschine (2); Erzeugen von Druckluft durch die Verbrennungskraftmaschine (2) anhand der ermittelten Betriebsparameter in einem verbrennungslosen Betriebszustand und Speichern der erzeugten Druckluft; und Einblasen der gespeicherten Druckluft in die Verbrennungskraftmaschine (2) anhand der ermittelten Betriebsparameter in einem Verbrennungsbetriebszustand der Verbrennungskraftmaschine (2) zur Druckerhöhung in einem Ansaugtakt; und eine entsprechende Vorrichtung (1).
Abstract:
This method operates an internal combustion engine (1) of an automotive vehicle (T) in compression braking mode and includes the steps of recovering at least a part of the exhaust gases of the engine (1) via EGR means (2), mixing the recovered gases with fresh air (F1) and fuel in order to form a gas-to-fuel mixture and injecting this gas-to-fuel mixture within at least a cylinder (12) of the engine (1) when a piston of this cylinder moves from its bottom dead centre position (BDC) to its top dead centre position (TDC). The engine (1) comprises two turbo-chargers (3, 4) whose turbines (31, 41) are located in two different exhaust lines (61, 62) which extend in parallel, downstream of an exhaust gas manifold (13).
Abstract:
The present invention relates to a method for reducing engine vibrations during engine braking with a malfunctioning engine brake, where said engine brake comprising means for altering a timing of at least one exhaust valve and means for varying an exhaust gas back pressure, comprising the steps of: detecting piston acceleration for each cylinder in the engine during the use of said engine brake, comparing said detected piston acceleration with a predetermined reference value, decreasing exhaust gas back pressure during engine braking if at least one piston is detected with a piston acceleration deviating more than a predefined amount from said predetermined reference value so that said piston acceleration will be falling within said predefined amount from said predetermined reference value.
Abstract:
A variable valve actuation system (72) is disclosed for providing exhaust to at least one component downstream of an engine (12). The system includes an exhaust valve (66) disposed in an engine cylinder and a hydraulic actuation system (98). The system also includes a braking control valve (84), a supply of hydraulic fluid (86) operably connected to the hydraulic actuation system, and an exhaust valve actuating device (114) operably connected to the hydraulic actuation system. The exhaust valve actuating device is operable to affect the exhaust valve to open within the engine cylinder. The system further includes a device (154) for controlling a position of the exhaust valve actuating device relative to a position of the exhaust valve. The controlling device is operably connected to the supply of hydraulic fluid.
Abstract:
A system and method of actuating one or more engine valves is disclosed. In one embodiment, the system comprises: a valve train element; a rocker arm pivotally mounted on a shaft and adapted to rotate between a first position and a second position, the rocker arm selectively receiving motion from the valve train element; a valve bridge disposed above the one or more engine valves; and a lost motion system disposed in the valve bridge.
Abstract:
Bei einem Verfahren zum Betrieb einer Brennkraftmaschine im Motorbremsbetrieb werden Drosselventile (11) geöffnet und ein Querschnittsstellglied (8, 9) zur Regulierung des Strömungsquerschnittes im Abgasstrang (4) in Stauposition überführt. Für den Fall, dass eine mit der Abgastemperatur korrelierende Kenngröße einen Grenzwert (Tgrenz) übersteigt, wird das Querschnittsstellglied (8, 9) kurzzeitig geöffnet und anschließend wieder in die Stauposition verstellt.