Mtu Friedrichshafen Gmbh

Mtu Motoren-und Turbinen-union Friedrichshafen Gmbh

Ktu Friedrichshafen Gmbh

Albert Kloos

Michael Willmann

Ralf Speetzen

Günther Schmidt

Andreas Kunz

Marc Hehle

Jörg Remele

Michael Walder

Gerd Huber

Jörge Remele

Stefan Müller

Guenther Schmidt

Paul Neumeir

G&uuml;nther Schmidt

A method for controlling an internal combustion engine with a common-rail system, in which a fuel quantity is computed from a measured fuel pressure distribution and in which the computed fuel quantity is set as the controlling value for controlling an injection. The fuel quantity is computed by measuring the pressure distribution (pE) of an individual accumulator, reproducing a modeled pressure distribution (pEMOD) according to the measured pressure distribution (pE) using a hydraulic model, and computing the fuel quantity from the hydraulic model.

Method for controlling an internal combustion engine

A method for controlling an internal combustion engine having a common rail system together with individual accumulators. A rotational speed-control deviation (dn) is determined from a target rotational speed (nSL) that represents the set point for an outer control loop to control the rotational speed, as well as from an actual rotational speed (nIST). A target torque (MSL) is determined from the rotational speed-control deviation (dn) via a rotational speed controller as a master controller. A target injection duration (SD(SOLL)) is determined from the target torque (MSL). The target duration injection (SD(SOLL)) represents the set point for an inner control loop for controlling cylinder-specific injection duration. An injection duration deviation is determined from the target injection duration (SD(SOLL)) and from an actual injection duration. A correcting variable is determined from the injection duration deviation via an injection duration controller as a follow-up controller, and an injection duration is determined from the correcting variable and the target injection duration for activating the injectors.

For an internal combustion engine with a common rail system including individual accumulators, a process for open- and closed-loop control is proposed, in which the individual accumulator pressure (pE) is detected within a measuring interval and stored, an absolute minimum value of the stored individual accumulator pressure (pE) is interpreted as the end of the main injection, and on the basis of the end of the main injection, a mathematical function is used to calculate a virtual starting time for the main injection. In the measuring interval after the end of the main injection, the individual accumulator pressure (pE) is filtered within a time window, a local minimum value of the filtered individual accumulator pressure is interpreted as the end of a post-injection, and a mathematical function is used to calculate a virtual start of the post-injection.

Process for the open-and closed-loop control of an internal combustion engine with a common rail system including individual accumulators

A method for detecting a preinjection in an internal combustion engine with a common-rail system, including individual accumulators, in which an individual accumulator pressure distribution is detected in a measurement interval and is used to determine an injection end of the main injection, in which a virtual injection start of the main injection is computed by a mathematical function as a function of the injection end, and in which the virtual injection start is set as the actual injection start of the main injection. With the preinjection activated, an actual injection delay for the main injection is determined as a function of the actual injection start, an injection delay deviation of a set injection delay from the actual injection delay is computed, and the injection delay deviation is used to determine whether a preinjection has occurred.

Method for detecting preinjection

In a method of controlling an internal combustion engine having a common rail fuel injection system including individual fuel storage chambers, wherein the pressure pattern of the fuel supplied to each injector can be determined and actual and virtual fuel injection ends and fuel injection begins are determined, the deviations from the desired fuel injection ends and from the fuel injection begins are calculated and the injectors are evaluated on the basis of the deviations and further control of the internal combustion engine is based on an evaluation of the fuel injectors.

Method of controlling an internal combustion engine

In a method of controlling an internal combustion engine with a common rail fuel injection system including individual fuel storage chambers for the supply of fuel to the various cylinders of the internal combustion engine, a fuel pressure (pE(i)) is determined during a measuring interval (MESS) and is stored, the existence of a significant change in the fuel pressure is determined as an injection begin (SB=f(pE(i), Phi)) or an injection end (SE=f(pE(i)), Phi), a virtual injection begin is calculated by way of a mathematical function (FKT) depending on the injection end (SE), and the virtual injection begin (SBv) is used as the actual injection begin (SB) for the subsequent control of the internal combustion engine.

Method of controlling an internal combustion engine with a common rail fuel injection system

A method and a system are provided for injecting fuel into the combustion spaces of an internal-combustion engine, in which case the injection system contains a number of fuel injectors each comprising an injection valve and a common feed and storage line supplying the individual fuel injectors with highly pressurized fuel. The beginning and the end of the injection of the fuel into the combustion chamber are controlled by opening and closing the injection valve. A defined lowering of the fuel pressure existing in the fuel injector takes place during the injection, so that the pressure which rises because of the ram pressure during the closing of the injection valve at the end of the injection in the fuel injector does not exceed a defined value, particularly preferably the system pressure of the fuel injection system.

Method of injecting fuel into the combustion chambers of an internal combustion engine, and fuel injection system for said engine

A fuel injection system for an internal-combustion diesel engine has a fuel injector, typically one of several, supplied by way of a high-pressure fuel line with highly pressurized fuel for the injection of the fuel into the combustion space of the internal-combustion engine during an injection operation. A pressure control valve connected in front of the fuel injector in the high-pressure fuel line is provided for controlling the pressure of the fuel injected during the injection operation. The pressure control valve contains a freely displaceable piston operating on both sides and a slide connected into the flow path of the high-pressure fuel line for the opening and closing of the passage cross-section of the flow path of the high-pressure fuel line as a function of the position of the piston. On the forward side of the piston, a first pressure space is provided which acts upon the piston in the opening direction of the slide, and, on the rearward side of the piston, a second pressure space is provided which acts upon the piston in the closing direction of the slide. An adjusting valve is used for adjusting the pressures in the first and/or second pressure space in the sense of a displacement of the piston in the opening or closing position. The fuel injection system according to the invention permits a proportional controlling of the fuel injection pressure during the injection operation over a wide adjusting range.

Fuel injection system for an internal-combustion engine

Within an injector housing, a nozzle needle comprising a nozzle needle shaft is accommodated in a first guide boring in a longitudinally displaceable manner. A nozzle prechamber which is arranged in front of the nozzle needle shaft and which is situated on the fore-part of the first guide boring is supplied with fuel via a high pressure channel. A control valve permits a control chamber, which is coupled to the nozzle needle and which is subjected to the action of highly pressurized fuel, to be relieved from pressure by opening the nozzle needle. According to a second embodiment, a spring chamber is configured as a high-pressure chamber on the rear side of the first guide boring that guides the nozzle needle shaft. The spring chamber is separate from the control chamber and contains a readjusting spring that impinges upon the nozzle needle in a direction of closure. This configuration prevents fuel exiting the nozzle prechamber from overflowing over the guide boring which guides the nozzle needle.

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Friedrichshafen, Germany

Albert Kloos