Robert Boschgmbh

Martin Zechnall

Uwe Kiencke

Ulrich Flaig

Helmut Denz

Ernst Wild

Alfred Schulz

Gunter Honig

Winfried Klotzner

Albrecht Clement

Rolf Daumer

Werner Nitschke

Hans Hecht

Jiri Marek

Klaus Heyers

Karl Ott

Herbert Goebel

Ingo Gorille

Ernst-Olav Pagel

Manfred Lembke

Claus Ruppmann

Christoph Treutler

Wolfgang Borst

Walter Stroh

Heinz Moller

Martin Willmann

Gerhard Will

Gunther Kaiser

Michael Kirschner

Dieter Mayer

Andreas Lock

Hans-Peter Stumm

Martin Person

Hans-Ulrich Gruber

Ekkehard Feldmann

Joerg Buth

Peter Etzold

Heinz Kraemer

Wolfgang Groschel

Helmut Breitkreuz

Dieter Walz

Gunter Rapp

Guenther Honig

A sensor has a thin film element, the thin film element having a temperature-dependent electrical resistance. The thin film element includes a platinum layer, which is doped with zircon or zircon oxide. The thin film element can be arranged on a membrane to create a mass airflow sensor.

Sensor having a thin film element

The invention is directed to a method for controlling the lambda value of the air/fuel mixture supplied to an internal combustion engine. The method utilizes the signal of a lambda probe as the measurement of an actual value with this actual value displaying discontinuities during the transistion from the rich to the lean lambda region. The switch-over of the control direction in the direction 'rich' is undertaken when the actual value in the form of the probe voltage passes through the reference voltage; however, this only happens when the probe voltage had an previously climbed to a threshold value 'rich'. Correspondingly, the control direction is swiched over to the direction 'lean' only when the reference value is passed through and when the probe voltage previously had dropped to a threshold voltage 'lean'. The apparatus which operates pursusant to the method no longer leads to undefined control oscillations when cylinder scatter effects occur.

Method and apparatus for controlling the lambda value of the air/fuel

An apparatus is disclosed for venting a fuel tank of internal combustion engines or the like, wherein fuel vapors developing in the tank are received in an intermediate storage unit containing an activated carbon filter and are delivered to the induction area of the engine in dependence upon operating conditions. The delivery is accomplished by an electrically controlled tank venting valve having a pass-through opening the cross section of which is continuously changed. This is achieved by changing the pulse duty factor of the drive pulse train for this valve. The pulse duty factor may be determined in the sense of a pure control using a family of characteristic fields in dependence on rotational speed and load of the engine, or by taking into account preferably averaged Lambda values with a reduction in the cross section of the pass-through opening of the tank vent valve as the mixture becomes richer. Further, an adaptive anticipatory control is provided which enters into the calculation of the fuel quantity to be supplied or of the fuel injection signal with a correction value (ATE) and switches over to a limit control when predetermined mixture proportions are reached. The basic adaptation in the Lambda control system for calculating the fuel supply is released only if the fuel quantities originating from tank venting are negligible.

Apparatus for venting a fuel tank

Pulse shaper for inductive transmitters

Method and apparatus for self-monitoring of microcomputer-controlled

Fluctuations of engine speed in the frequency range from 2 to 8 Hz, which produce 'bucking' behavior of a motor vehicle, are detected by passing engine speed signals through a filter which reduces and delays the oscillations and a difference signal is then produced between the original and the processed speed signal in order to derive an alternating signal in the form of a square wave indicating the sign of a correction to be made to engine ignition timing for counteracting the bucking oscillations of engine speed. The square wave determines the sign of an anti-bucking ignition timing correction factor, of which the absolute value may be constant or may vary according to the sign of the correction and, if desired, also in accordance with engine operation parameters.

System for damping bucking oscillations of an automobile engine

The switching off of one or more cylinders of a multicylinder engine to save fuel when the engine is running lightly loaded has been found to reduce the effectiveness of computer control of ignition timing and fuel injection unless additional fields of stored control information are provided for responding to the various combinations of engine parameter values that arise in operation. Accordingly, with each step of reduction of the number of working cylinders, the control of ignition timing and fuel injection is shifted to a different bank of fixed value memory (ROM).

Ignition and fuel injection system for multicylinder engines

To permit operation of engines, particularly turbo-charged engines, at the maximum power level just short of causing engine knocking, and preventing engine knocking, temperatures in the engine are sensed and, if an excessive temperature signal is detected, for example excessive engine temperature, exhaust gas temperature, turbo-charged air, or turbo charger temperature, a fuel supply system, for example a fuel injection system, is controlled to enrich the mixture, for example by multiplying the fuel injection time by a factor as commanded by an additional control stage (26, 27, 30) which stores in a memory, such as a ROM (27), engine operating characteristic curves. In addition, spark retardation by a retarding angle (.alpha.1) can be commanded, the spark retardation in combination with enriching of the fuel-air mixture being less than without such enrichment, thus permitting operation of the engine at appropriate power and efficiency level without noticeably increasing fuel consumption in the course of continued operation of the engine.

Internal combustion engine control system for use with turbo-charged

In order to diminish the lurching which occurs when automatic transmissions of motor vehicles perform gear changes, the invention describes apparatus for gradual changes of the engine torque at or near the onset of the gear change as well as at or near the time of gear reengagement. The engine torque may be changed by altering the fuel metering characteristics and/or the ignition timing in a gradual and controlled manner.

Torque control for internal combustion engines

A fuel injection system receives valve control pulses, the length of which determines the fuel quantity delivered to the engine. A first counter receives a pulse train whose frequency depends on the air flow rate and this pulse train is admitted for a period defined by the engine speed. The content of the counter is then counted out at a frequency which is synthesized from operational parameters of the engine, including, in particular, the temperature. For this purpose, there is generated a temperature-dependent frequency which is fed to a multiplier circuit which combines this frequency with data derived from a memory to generate an output signal which is further processed to provide the fuel injection pulses for the engine.

Apparatus for determining the duration of fuel injection control pulses

Transmission gear change characteristic curves, relating speed and loading, are stored in a memory. The digitally stored data are processed in a data processing unit connected to a synchronization and logic unit which controls a gear change control stage, actually controlling the gear shifting. The data processing unit compares output speed of the transmission with the characteristic curves stored in the memory relating speed and loading, and optimum transmission gear range, while additionally considering load signals derived from the engine to which the transmission is connected. Preferably, the entire unit is synchronized by output pulses derived from the output speed of the transmission, with prohibited states and gear changes being provided for to prevent shifting if the actual speed exceeds or recedes below critical levels.

Automatic transmission digital control system

The engine for which the system provides ignition control produces a basic signal giving the time lapse of a predetermined angle of crankshaft rotation. Leading and trailing edges of this basic signal produce control signals. During the interval between these two a first counter stepped by clock pulses produces a count proportional to engine speed down to a certain relatively low engine speed beyond which overflow of the counter holds the counter at its maximum value. The count so determined is utilized in an ROM as the engine speed parameter which together with other engine operation parameters produce the address that selects the appropriate number to control computed ignition timing. According to the engine speed range, a second counter is loaded either with the number provided by the ROM, or with a count number based on engine speed only and the second counter then counts down past thresholds provided by a second ROM to determine both the moment of closure of the electronic switch and the moment of opening. The closure interval is generally maintained constant, consistently so at low speeds, but at high speeds a minimum open interval of the electronic switch in the primary circuit of the ignition transformer overrides this requirement. In certain embodiments ignition timing is provided by the reaching of a threshold value of current in the primary winding, under certain limited conditions.

Digital-electronic engine ignition system

A pair of marker signals are generated with respect to a predetermined crankshaft position; the leading edge of the marker signal is used as a control edge to generate, by digital calculation, a digital control signal calculated in accordance with engine operating characteristics, as related to speed, loading, and the like, and providing a numerical output value used as a control value to control the timing of a pulse which may, depending on use, control: ignition timing; fuel injection timing; transmission gear shifting, the data relating engine performance, with respect to loading, speed, and other parameters such as temperature, starting conditions, and the like, being stored in a data memory. Calculation of the digital control signals and determination, by timed sequential counting out, are carried out independently from each other and during time overlap. Under starting, or emergency condition, an override can be provided coupling the trailing flank of the marker signal -- occurring, for example, at upper dead-center position of the cylinder -- to the output of the system to provide directly generated ignition pulses.

Method and apparatus to determine the timing of a periodically

Operating parameters, such as speed and loading of the engine are converted in electrical signals which are converted into pulse rates, to control counting of an address counter, addressing a read-only (ROM) memory in which characteristics of the engine are stored. To provide easy introduction of additional parameters such as temperature, idle condition, maximum speed, start condition, etc., the final value of an accumulator counter, the number of which at a given time controls the ignition timing, can be changed; further, to simplify the system, the speed and load signals are processed during a portion of the time between successive ignition events, the remaining portion of the time being controlled solely by one of the parameters (preferably speed), thus simplifying the circuitry by providing a transfer switch connecting for the remaining period only the selected (preferably speed) signal to the accumulator counter, the count state of which controls the ignition instant.

System to control timing of cyclically repetitive events, particularly

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Schwieberdingen, Germany

Martin Zechnall