Robert Boschgmbh

Gunter Honig

Uwe Kiencke

Alfred Schulz

Theodor Gast

Ulrich Flaig

Martin Zechnall

Gerhard Lotterbach

Udo Zucker

Rainer Bone

Heinz Moller

Rudolf Nagel

Helmut Kauff

Bernward Boning

Kurt Binder

Heinz Theuerkauf

Peter Dilger

Georg Haubner

Jurgen Wesemeyer

Karl Ott

Edmund Jeenicke

Immanuel Krauter

Manfred Schwab

Winfried Klotzner

Werner Meier

Hans Schrumpf

Ingo Gorille

Ernst-Olav Pagel

Manfred Schenk

Wolfgang Borst

Gunther Kaiser

Thomas Zeller

David Van Belzen

Jorg Birmelin

Joachim Braunger

Detlev Zieger

Jan-Faas Van Woudenberg

Imanuel Krauter

The invention is directed to a method and an arrangement for controlling an internal combustion engine wherein the air flow to the engine is influenced at least in component ranges and in a selectable time reference to operations in the engine.

Method and arrangement for controlling an internal combustion engine

The invention is directed to a method and an apparatus for measuring the air-flow rate in the intake tube of an internal combustion engine using a flow-measuring device which is insensitive to the direction of flow. In order to avoid incorrect measuring results when pulsations of the air flow occur, the reverse flow is sensed and, based on a total flow signal, deducted to determine the forward flow. At the points where the direction of flow is reversed, certain physical relationships prevail between flow-measuring signal, differential pressures, the presence of maxima and minima in the flow signal and the gradient of the flow signal. Several methods are disclosed to determine these reversal points as are flow charts for a computer-controlled determination of the air-flow rate.

Method and apparatus for measuring the rate of air flow in the intake

A control device having certain criteria which must be fulfilled in order to trigger an acceleration enrichment. Criteria are a defined number of successive load values of increasing tendency and/or an actual load value with a defined distance above the arithmetic mean of a number of preceding load values. For the acceleration enrichment itself operational parameters, such as rpm, load, load gradient, temperature and number of revolutions since the triggering of the acceleration are processed.

Control device for a fuel metering system of an internal combustion

To permit simple computation of control parameters, for example by an engine microcomputer, operating parameters of the engine are signalled by sensing instantaneous operating conditions such as speed, induction air pressure, or the like, preferably at a sensing angle of the crankshaft in advance of top dead center (TDC) position of a reference piston, and the average value is then determined by weighting the sensed instantaneous value to relate it to an average value in a weighting circuit (16). Preferably, the sensed signal is additionally modified in a function generator (15) as a function of then pertaining average conditions of at least one of: speed n; loading L.

Apparatus for determining the value of a cyclically varying parameter of

An electromagnetically excited vibrator with arms carrying baffle members at their ends that are immersed in the flow to be measured is mounted at one or more vibration nodes to reduce loss of vibratory energy to the casing of the flow meter. A flat magnetically conducting cross shape can be mounted at a node in the middle, provided each cross beam of the cross is vibrated in flexure, and the two cross beams vibrate in phase opposition (counter stroke). Such a vibrator is excited by a similarly crossed pair of E-shaped cores with exciter and secondary windings on the middle legs of the cores, or by a coaxial re-entrant core with permanent magnet wafers set in the rim at respective locations separated by an air gap from the arms of the cross. In each case the vibrator can be firmly affixed to the central leg or legs of the core. A two-ended rod system can be excited by magnetostriction, operating differentially on a split middle portion of the core, while the latter is supported at two nodes located between the split middle portion and the respective ends that carry baffle members. Evaluation circuits in all cases measure the vibration damping caused by fluid flow.

Vibrator damping flow meter

The mass flow rate of a fluid, for example a gas or air, for example passing through a duct or the like, is determined by placing a vibrating element in the path or stream of air flow, and measuring the damping thereof due to the air flow; the damping can easily be measured, in accordance with the invention, by connecting the vibrating element in a circuit having a servo system including a controlled variable amplifier and a comparator, such as a proportional-integral (PI) controller (14) comparing the signal on the vibrating element with a reference establishing a vibrating amplitude and, in turn, controlling the amplification of the variable amplification amplifier (8) to maintain a constant amplitude of vibration, the control signal controlling the variable amplification amplifier being a measure of the damping, and hence of mass flow rate. To eliminate damping due to extraneous conditions, such as clamping of the mechanical vibrating elements, connection of electrodes and the like, an alternating current (10a) can be fed to the vibrating element, the alternating current having a frequency which is high with respect to the vibration frequency, and then being filtered out by a band-pass filter (17) tuned to the alternating current frequency, the level of the signal across the vibrating element being subtracted from the overall damping signal to thereby eliminate errors due to inherent damping of the mechanical system independent of fluid flow.

Mass flow meter with vibration sensor

The knock sensing equipment has a control circuit which generates gating signals for dividing the operation into a measuring phase and a test phase. In the latter, the possible malfunction of the sensor is determined. During the test phase, the sensor responds either to background noise or to a test voltage and the sensing output signals are compared to a predetermined minimum and/or maximum level. Malfunction is indicated if the signals furnished by the sensor are outside of the indicated range.

Knock sensing apparatus with fail indicator for use in an internal

A voltage-frequency converter having a chargeable and dischargeable memory, a comparator circuit and a subsequent multivibrator, wherein the charging and/or discharging signal for the memory is obtained from special signal sources. At constant charging and discharging signals, a linear voltage-frequency conversion is provided. In the case of variable charging or discharging voltages, non-linear signal conversions are possible. The multivibrator may be a digital monostable multivibrator, to effect precise, reproducible and quantifiable period durations in the output signal of the converter, and thus a very precise voltage-frequency conversion.

Voltage-frequency converter

Signals from a coil producing pulses in response to flux variations produced by a rotary member driven by an engine crankshaft are applied in push-pull through series resistors to the inverting and non-inverting inputs of a comparator. A variable voltage divider for the input signals is provided by a pair of complementary transistors respectively connecting the comparator inputs to opposite poles of a fixed voltage supply. The comparator pulses charge a capacitor through a transistor, the capacitor being periodically discharged through a resistor, once per crankshaft revolution. An increase of capacitor voltage beyond a very small amount progressively lowers the resistances provided by the transistors connected to the comparator inputs, acting on one of them simply through a transistor and on the other through a transistor and a current mirror circuit. In order to compensate for the temperature dependent leakage current of the transistor driven by the comparator output in order to charge the capacitor, a second current mirror is provided that prevents charging of the capacitor during the blocked-condition of the transistor in question. A supplementary voltage divider is connected through isolating series resistors to set the d.c. level of the comparator inputs when the transistors connected to these inputs are non-conducting.

Evaluation circuit for electrical signals

To positively allocate output signals from a transducer scanning marker elements arranged at a uniform distance from the center of a rotating disk, the markers are located around the circumference of the disk in accordance with a predetermined pattern, for example, uniformly distributed 30.degree. apart, or distributed with uniformly increasing relative distances, and an additional market element (33) and forming a reference marker is located in the zones between adjacent markers spaced from a neighboring marker element (21) of the plurality of marker elements by a distance which is substantially larger than the angular distance with respect to the marker element at the other side of the reference marker. The outputs from a pick-up sensor are evaluated by applying the outputs to two counters, counting a different clock rate, the count output of one of the counters being stored and compared with a subsequent count state of the other counter operating at a higher clock rate. If the second counter has not reached the previously stored count, a positive indication that the sense marker as the reference marker is obtained, permitting a comparator to switch over a transfer switch to route the sensor output to a line indicating that the marker was the reference marker; if the faster-counting counter has, however, reached the count state of a slower counter in the prior cycle, an indication is obtained that the marker is a regularly recurring one, thus permitting control of the transfer of the output from the sensor to a routing line indicating that the marker is a regularly recurring one. The count rates are preferably sufficiently different to accomodate expected variations in speed of rotation of the disk within the recurrence time between adjacent markers.

System and apparatus to determine the angular position, and speed of a

A fuel metering apparatus in an internal combustion engine is proposed, in which the metering signal is correctable in accordance with the mixture composition and/or the exhaust gas composition, this composition is detected by means of a sensor for at least one component of the mixture and/or exhaust gas, and the sensor signal proceeds to a single threshold switch for evaluation. The output level of the threshold switch is monitored in its course and the correction signal as well as an error recognition signal are derived from it.

Fuel metering apparatus in an internal combustion engine

An apparatus for controlling the current through an electromagnetic injection valve of an internal combustion engine during its pickup and holding phases by opening and closing a first switch connecting the valve to a voltage source. The first switch is initially closed by a valve timing circuit to initiate pickup of the valve. A first current-sensing resistor connected in series with the first switch produces a signal to open the first switch when the valve current attains an upper threshold value which assures valve pickup, and to close a second switch connected in series with a second current-sensing resistor across the valve. When the valve current drops to a lower threshold value greater than the valve drop-out current, the second current-sensing resistor produces a signal to reclose the first switch and open the second switch for a predetermined time, after which the first switch is again opened and the second switch closed. The cyclic opening and closing of these switches by the second current-sensing resistor continues until both switches are opened by the valve timing circuit. In another embodiment, the pickup time of the valve is determined by measuring the time for the valve current to increase to a predetermined value after it is first energized by the value timing circuit, and the valve holding time is adjusted in accordance with the valve pickup time, to assure correct fuel injection even when the voltage source is not maintained constant.

Apparatus for controlling the current through an electromagnetically

To supervise a program controlled device which is subject to stray noise or disturbance pulses, particularly microprocessor controlled automotive vehicle electronic systems, a timing circuit is provided responsive to check pulses added to the program and defining a timing interval, the monitoring system distinguishing between disturbance pulses and static defects by supervising the control pulses and, upon failure of the control pulses, generating a program restart or interrupt signal, respectively, which both initiate a new start of the program cycle or, respectively, define a timing interval which, upon failure to sense further control pulses, initiates energization of an emergency switching system. Continuous failure to receive control pulses also can initiate the emergency switching system. To permit start-up, and before control pulses are obtained, a time delay circuit is provided which disables the monitoring system upon switching ON of the program controlled device at least for the time period of one check pulse cycle.

Monitoring system for program controlled apparatus

In order to suppress the train of detector oscillations after the disappearance of the engine knock phenomenon, the invention provides a piezoelectric oscillator which is set into vibration by engine knock and includes circuitry for applying signals of opposite polarity to the oscillator at times when no engine knock is expected. Accordingly, the output of the piezoelectric engine knock detector is used only in a relatively narrow time interval during the combustion cycle. In the remaining interval, the circuit switches over to a configuration where the oscillations of the piezoelectric oscillator are damped. The construction of the invention makes it possible to discriminate between different cylinders of a multi-cylinder engine and to assign the knock phenomenon to particular engine cylinders. A number of embodiments is presented.

Apparatus for detecting oscillations occurring during engine knock

Data signifying the value of a controlled parameter which varies as a function of engine speed is stored on a disk rotating with an engine shaft. A sensor senses the data starting with a predetermined reference position and extending over a predetermined fixed scanning time. Since the time is fixed, the angle of rotation covered by the sensor will vary as a function of engine speed. The data is so arranged along the disk that the value of the parameter at the given speed can be determined from the sensed data at the end of the scanning time. The data is stored either as markings to be sensed serially from the start to the end of the scanning time, or is stored in parallel tracks to be sensed simultaneously at the end of the scanning time. For straight line approximations of the characteristic curve specifying the variation of the parameter as a function of speed, the disk has tooth-like segments indicating the required slopes, intervals for which the slopes are constant, and sign of the slopes by the length of the segments and/or the interval between segments.

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Ditzingen, Germany

Gunter Honig