Robert Boschgmbh

Erich Singer

Ulrich Drews

Hans Schnurle

Hans Kubach

Bernd Kraus

Eugen Joos

Hermann Gassler

Peter Werner

Wolfgang Maisch

Werner Jundt

Harro Herth

It is proposed for a fuel metering system that a final control element be triggered with a regulated direct-current signal having clock components dependent on operating characteristics of an internal combustion engine in order to influence a fuel metering means. A further proposal is that the acceleration enrichment be triggered during starting. In this manner the desired starting enrichment is obtained by way of the sum of the post-starting, warm-up and acceleration enrichment. The acceleration enrichment per se begins beyond a predetermined air flow gradient and then has a steady course up to a maximum value. This subject is disclosed in combination with a continuously operating injection system, in which a corresponding overall control signal is prepared in a control unit and delivered to an electrohydraulic final control element. This final control element, in the specialized example, influences the working pressure of the differential pressure valves associated directly with the continuously functioning injection valves.

Electronically controllable and regulatable fuel metering system of an

A current regulator is proposed for use in an electronically controlled, continuously operating gasoline injection system, with the aid of which a control element can be supplied with different current values depending upon the operating states of the engine. In addition to a current regulating phase during active operation, it is possible with the proposed current regulator to reverse the direction of current flow in the control element for the sake of blocking the supply of fuel during overrunning. Towards this end a circuit apparatus links signals relating to rpm, throttle valve position and temperature. Furthermore two safety circuit arrangements are proposed for the current regulator, so that in case of a failure of important components there is no impairment of safety, and emergency operation is assured.

Current regulator for an electromagnetic consumer for use with internal

A control circuit of a fuel management control system for internal combustion engines monitors the operation of an exhaust line sensor. When the oxygen sensor is perceived to be inoperative, for example, due to low ambient temperature, the previously closed loop control process governing the fuel management control signals is interrupted and a direct forward control process is substituted therefor. The reference voltage is changed during this time for eventual adaptation to the changeover to closed loop feedback control after the oxygen sensor again becomes operational.

Method and apparatus for controlling fuel management for an internal

An electronic circuit is described for use with an existing fuel injection system in which fuel control pulses are generated on the basis of air flow rate, engine speed and exhaust gas composition. In particular, the existing fuel injection system is assumed to include an exhaust gas sensor with a signal integrator and a throttle position switch which indicates a closed throttle. It is also assumed that the fuel injection system shuts off fuel control pulses when the throttle is closed and engine speed drops below a predetermined value. The present circuit is intended to recognize this fuel shutoff and to set the integrator at an average value irrespective of the 'too lean' signal which it receives from the exhaust gas sensor. In this way, upon termination of fuel shutoff, the engine will receive an average mixture rather than a highly enriched one.

Auxiliary fuel injection control circuit

An apparatus for use in association with a fuel mixture preparation system for an internal combustion engine in which the output signal from an oxygen sensor located in the exhaust system is used to provide closed-loop control of the mixture ratio supplied by the mixture preparation system. The apparatus includes a principal comparator in which the sensor signal is compared with a reference value and a subsequent integrator which supplies correcting signals to the mixture controller. A special circuit between the principal comparator and the integrator can delay the signal transmission between these two elements in one direction of change, thereby causing an effective shift of the point of operation of the control loop to a different point in the sensor output curve, to compensate for aging, etc. The feedback branch of the integrator includes circuitry which effectively provides two different constants of integration to enhance smooth running at low engine speeds and to improve the control response at high engine speeds. The invention may be used with any kind of mixture preparation system, e.g., carburetors, intermittent injection systems and continuously acting injection systems.

Apparatus for adjusting the combustible mixture of an internal

The maximum speed of an internal combustion engine is limited by a device which compares the period of rpm-synchronous pulses with the time constant of a reference multivibrator. If the engine rpm is so high that a pulse terminates prior to expiration of the reference time period, a gate is activated and acts through further multivibrator circuits to interrupt the fuel delivery to the engine, e.g., the fuel injection control pulses are suppressed. If the maximum rpm is exceeded only intermittently, the device restores normal fuel injection control pulses after a predetermined number of pulses has been suppressed. If the maximum rpm is exceeded continuously, the device restores normal fuel control somewhat later than the time at which the engine speed drops to below maximum rpm.

Growing community of inventors

Besigheim, Germany

Erich Singer