Robert Boschgmbh

Alfred Kratt

Gunther Plapp

Cornelius Peter

Robert H Entenmann

Rolf Kohler

Claus-Dieter Nusser

Rudolf Moz

Gunter Braun

Klaus Ries-Mueller

Manfred Mezger

Winfried Langer

Hermann Nusser

Juergen Foerster

Wolfgang Kosak

Bernd Kraus

Rainer Frank

Thorsten Allgeier

Manfred Lembke

Rainer Schillinger

Claus Ruppmann

Rudiger Jautelat

Anwar Abidin

Helmut Schwarz

Botho Zichner

Klaus Franzke

Eberhard Lang

Markus Lischwe

Rolf Schleicher

Hans-Martin Muller

Jens Thurso

Christian Mengler

Jürgen Foerster

In a method for generating an internal combustion engine configured to run on both a gas fuel and a liquid fuel, the shutoff valve of the gas injection system is initially closed, the engine is then operated with the liquid fuel, and subsequently all gas injection valves of the gas injection system are opened in a predefined pattern while the shutoff valve is still closed.

Method and device for operating a gas injection system of a gas fuel and a liquid fuel operated internal combustion engine

The invention is directed to a method for detecting and documenting exhaust-gas relevant malfunctions of a vehicle having an internal combustion engine. The method includes the steps of evaluating the operating state of at least one component of the internal combustion engine in a circuit arrangement to delimit faults, which are caused by improper operation of the vehicle, relative to faults based on defects of the vehicle system; and, outputting a fault announcement and storing the fault announcement in a fault memory in dependence upon the operating state of the component.

Method of detecting and documenting exhaust-gas relevant malfunctions of

A device for determining a load signal indicating the actual air mass per stroke in an internal combustion engine based on signals which indicate the respective instantaneous air flow rate in the intake pipe, these signals being indirectly or directly summed up over a specified angular range of the crankshaft for forming the load signal. In first predetermined ranges of speeds and throttle-valve positions, the load signal serves directly as a computational basis for the quantity of fuel to be injected. In second predetermined ranges, the last value from the first ranges is subjected to a speed-dependent correction and this corrected value is used as a substitute load signal.

Device and method for determining a load signal in an internal

The invention is directed to a method for checking the operability of a conduit system conducting a fluid flow. The conduit system is for an internal combustion engine and utilizes two fluids having temperatures which are different from each other. In this way, it is possible to set quite well-defined measuring conditions. The fluid flow in the conduit system to be checked is coupled to the temperature sensor in such a manner that the temperature thereof changes with a relatively steep gradient when, starting at a specific time point, the above-mentioned fluid operates to warm the temperature sensor. When the magnitude of the gradient remains below a threshold value, the conduit system checked is evaluated to be operational. The measurement is reliable even though it requires only a single temperature sensor.

Method and arrangement for checking the operability of a fluid-flow

In a method and apparatus for limiting the speed of motor vehicles, in cases where a speed signal is not available, engine cut-off is not rigidly activated upon exceeding a constant rotational speed threshold. Rather, a variable rotational speed threshold is determined which takes into account instantaneous or previous driving states, thereby being responsive to instantaneous or previous reactions of the vehicle's driver. This provides for an intelligent engine cut-off which accounts for operating conditions and, thus, can substantially better respond during critical driving situations.

Method and device for limiting vehicle speed

The signal from a vibrationally-sensitive pressure sensor is both low-pass filtered and band-pass filtered. The low-pass-filtered portion is employed as a pressure-measuring signal, while the band-pass filtered portion is used as an acceleration-measuring signal. The pressure sensor is preferably installed in the tank-venting installation of a motor vehicle to measure the pressure differential relative to the surroundings. The acceleration-measuring signal is used to stop a recognition of engine misfiring, as soon as a rough road surface is recognized as a result of this signal.

Method and system for evaluating a signal from a vibrationally-sensitive

The invention relates to a method and an arrangement for monitoring the operability of a heater of an oxygen-measuring probe which is mounted in the exhaust-gas channel of an internal combustion engine. The principle of operation of the invention is based on the fact that the supply voltage of the probe heater drops during loading by the electrical resistance of the heating element. The voltage difference is dependent upon the magnitude of the resistance and therefore at least the three states can be distinguished, namely: normal operation, circuit interruption and short circuit. The operational state of the probe heater which is so determined is displayed to the driver by activation of a corresponding control unit and/or is stored, as required, in a fault memory. The arrangement according to the invention can be realized by a computer or in a compact configuration and is suitable for use in a central control apparatus.

Method and arrangement for monitoring the operability of a heater of an

In a method for reducing the fuel supply for one cylinder of a multi-cylinder internal combustion engine with centralized injection, the procedure is that the cylinder located in the intake cycle sequence in front of the cylinder whose mixture is to be made much leaner, for example because of unreliable combustion, is already supplied with less fuel than is the case when all cylinders are operable. In addition, the intake cycle for the failed cylinder itself is supplied with as little fuel as possible. Using this method, it is possible to set a very lean mixture in the failed cylinder but a mixture having a lambda value close to 1 in the remaining cylinders. This ensures that the motor vehicle in which the internal combustion engine with the failed cylinder is operating can still be reliably operated and, at the same time, there is no risk of overheating of the catalytic converter.

Method for reducing the fuel supply for one engine cylinder

Method and arrangement for adjusting fuel for emergency operation

Device for controlling an operating characteristic of an internal

An actuating device is proposed which is used to adjust a throttle valve disposed in the intake tube of an internal combustion engine. The actuating device includes a gas pedal adapted to engage an actuating lever, which is supported rotatably relative to a throttle valve shaft, so as to pivot counter to the force of a restoring spring. Connected to the actuating lever is a follow-up drawing spring, which is secured with one end to an intermediate lever provided with a cam disk having a curved camming surface which surface a lever arm is supported so as to operate a damper element. The intermediate lever is rotatably supported with respect to the throttle valve shaft and with a coupling stop engages a throttle valve lever, which is connected to the throttle valve shaft such that relative rotation between them is prevented. The throttle valve lever is drawn against the coupling stop by means of an uncoupling spring disposed between the intermediate lever and the throttle valve lever. An idling actuator also engages the throttle valve lever. When the actuating lever is actuated in the clockwise direction, the intermediate lever is drawn in a damped follow-up manner by the follow-up drawing spring to adjust the throttle valve via the throttle valve lever.

Actuating device for throttle valve

In a method and apparatus for controlling tank venting in internal combustion engines, a regenerative flow of fuel is released from the activated charcoal container to the negative-pressure side of the intake tube of the engine and an adaptation in the computer area for the fuel metering quantity simultaneously is prohibited, or vice versa, an adaptation is authorized and a regenerative fuel flow is prohibited, by cyclical triggering, as a function of whether the throttle flap angle drops below, or exceeds, a predetermined threshold value. Parallel to this, a continuous activated charcoal filter regeneration is provided that comes into play at relatively large air throughputs, by means of a branch line leading into the air filter area upstream of the throttle flap; furthermore, if the throttle flap angle threshold value is exceeded, both the regenerative fuel flow via the tank venting valve and the adaptation in the computer area are authorized.

Method of controlling tank venting in an internal combustion engine and

A method and apparatus are disclosed for measuring the flow rate of a medium flowing through a pipe. The invention is particularly for measuring the rate of air flow in the intake pipe of an internal combustion engine by means of a throughput sensor which is insensitive to the direction of flow. The throughput sensor can be a constant-temperature anemometer. The analog output signals of the sensor are converted into a sequence of discrete numerical values with an adjustable sampling rate, wherein the periodic output signal characteristic of the flow meter is weighted for determining the occurrence of changes in the direction of flow, and wherein the duration of time in which the direction of flow is changed is considered in the determination of the flow rate via corresponding correction factors. In the method and apparatus of the invention, the points in time at which changes in the direction of flow occur are determined according to the following steps: (a) comparing the differential values of successive numerical values of the number sequence with a first threshold value particularly dependent on the sampling rate; (b) determining the characteristic time points at which the first threshold value is exceeded or drops below; and, (c) recognizing the change of flow direction with the occurrence of more than two characteristic instants per period of the output signal.

Method for measuring the flow rate of a medium flowing through a pipe

A failsafe emergency operation device for the idling operation of motor vehicles, in particular for a digital idling charge regulation having a final control element triggered by an end stage circuit, which final control element, as a two-coil rotary adjuster, controls the cross section of an air bypass parallel to the throttle valve. A central computer (microprocessor, microcomputer) prepares a digital trigger signal for the end stage having a duty cycle which is variable depending upon the final control element position required. At the same time, at at least one position of the final control element, an end stage monitoring signal which is to be fed back is prepared and fed back to the computer, which via a separate shutoff stage for the end stage makes this end stage current-free whenever agreement does not exist between the two signals in terms of the duty cycle. A failsafe circuit is furthermore provided, which receives separate control pulses or is supplied with the duty cycle trigger signal supplied to the end stage by the computer, and in case of malfunction this failsafe circuit emits a reset signal, which likewise shuts off the end stage, resets the microcomputer, or alternatively can throw an emergency operation generator ON, which generator then supplies the end stage with an emergency operation duty cycle for triggering it.

Failsafe emergency operation device for idling operation in motor

A system for regulating rotary speed of an internal combustion engine includes an idling volumetric efficiency or charge regulating system and an overrun or push cutoff system to maintain a minimum rotary speed of the engine during important operational modes. The system is provided with means which eliminate undesired overrun cutoff of intentionally increased rotary speeds of the engine induced by the idling volumetric efficiency regulating system. The actual value of the control signal produced by the regulating system is compared with a limit or threshold value and after the threshold is exceeded the function of the overrun cutoff device is blocked. The regulating system includes a PID regulator which in combination with the circuit of this invention produces a dynamic behavior of the resetting rotary speed of the overrun cutoff function.

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Schwieberdingen, Germany

Alfred Kratt