Robert Boschgmbh

Gunter Braun

Alfred Kratt

Werner Jundt

Wolfgang Kosak

Helmut Janetzke

Wolfgang Krampe

Norbert Miller

Rolf Schleicher

Jurgen Nager

Process and device for influencing the air feed in an

The invention is directed to a mixture metering arrangement for an internal combustion engine with a digital data processor, particularly a microcomputer, the signal processing pattern of which is governed by clock pulses, and with a signal generating means which delivers analog output signals. The signal generating means is responsive to operating parameters of the internal combustion engine and is an exhaust gas sensor responsive to the air ratio Lambda. The exhaust gas sensor is used in a closed-loop control system to influence the air-fuel ratio and changes its output quantity at the air ratio of Lambda=1. In this arrangement, a correcting stage corrects the influence of a delay time (t.sub.v) connected with the clocked signal processing on the mixture formation. The delay occurs in the transmission of the change in the output of the sensor. Two methods are indicated for the mode of operation of the correcting stage by means of which a mean value shift of the quantity (F.sub.R) influencing the mixture formation is avoided and the concentration of toxic substances in the exhaust gases is minimized. Flowcharts are disclosed to realize the invention by means of a suitably programmed microcomputer.

Mixture metering arrangement for an internal combustion engine

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

In a system for regulation of the idling speed of an internal combustion engine acting through an electrical positioning means for the minimum-opening position of the throttle valve, the building-up of troublesome fluctuations in engine speed as the result of the characteristics of the regulation loop is counteracted in response to detection of the rise of such fluctuations or of their imminence as the result of an excessively rich mixture (on the basis of the signal from a probe in the exhaust pipe). When such a condition is detected, the amplification factors in the controller stage of the regulation loop are reduced, the reference desired idling speed value is raised and the lower limit of the regulation range is also raised. These parameters are returned to normal when the throttle valve moves away from its idling speed position.

Apparatus for regulating the idling speed of internal combustion engines

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Freiberg, Germany

Gunter Braun