Abstract: A system for automatically controlling the idling speed of an internal combustion engine, comprising a valve, for supplying an adjustable quantity of additional air, and means for controlling the setting of the valve as a function of the detected speed of the engine and comparison with an idling speed range, and as a function of the detected pressure in the intake manifold and comparison with a value equivalent to the required air supply.

Abstract: A carburettor or other combustible mixture generator 1 has a mixture chamber 3 surrounded by a tubular wall 2 which has an inner skin 9 and an outer skin 10 with an annular heating chamber 11 between them. Heating fluid such as exhaust gas or heated engine cooling water flows through the chamber 11 from an inlet 12 to an outlet 13 and so heats the inner skin 9. A fuel metering device 6, 7 directs the fuel on to the surface of the heated skin 9 and thus causes the fuel to be evaporated within the mixing chamber 3 upstream of a throttle 4. This greatly improves the uniformity of the mixture and the uniformity of its distribution through an inlet downstream of the throttle 4.

Abstract: An internal combustion engine is provided with an ion current sensor in the exhaust conduit. The sensor may be simply a spark plug across which is applied the vehicle battery voltage. The operation of the engine at various values of mixture composition yields characteristic curves for the ion current and for the fluctuations in the ion current as a function of the air number. These characteristic data are used to provide set point values against which the prevailing ion current is compared. If a set point value is exceeded, the fuel-air mixture is adjusted accordingly by an integral controller.

Abstract: In order to produce a transition mixture enrichment during acceleration of an internal combustion engine, a carburettor or other mixture generator 1 of the engine with a mixing chamber 2, a main throttle 4 and a choke valve 5, has the choke valve 5 operated by a quick-acting electric drive 6, for example a two-coil rotary setter, which is controlled by a microprocessor 8. The microprocessor is fed with signals which sense the opening of the main throttle 4 and preferably also other engine operating parameters such as temperature and speed. When the main throttle 4 is opened to accelerate the engine, the microprocessor 8 causes the electric drive 6 to close the choke valve 5 abruptly and temporarily. The extent of closure of the choke valve 5 is dependent upon the extent of the throttle opening and on the other operating parameters to give the required mixture enrichment. This arrangement avoids the necessity to provide an accelerator pump.

Abstract: A method and apparatus for closed-loop control of the air number .lambda. in self-igniting internal combustion engines, wherein with the aid of an ion current sensor disposed in the immediate vicinity of an outlet valve, the extent of the post combustion reaction of the exiting exhaust gases is detected and the ion current produced is compared with a set-point value, which lies within the ion current characteristic curve, which sharply drops within the air number range of .lambda.=1.0-1.5. In accordance with the result of the comparison, one component of the operating mixture of the engine is varied in amount in corrective fashion, so that the set-point value of the ion current is maintained and thus the permissible soot number of the exhaust gas is not exceeded.

Abstract: A constant pressure carburettor comprises a mixing chamber 2 which is surrounded by a heating jacket 12, an operator controlled throttle valve 3 at the downstream end of the chamber 2, a fuel feeder 5, 6 at the upstream end of the mixing chamber and a choke valve 10 at an air inlet to the carburettor. The choke valve 10 is, in use, controlled automatically by the air flow into the carburettor in dependence on the opening of the throttle valve 3 and the speed of the engine to which the carburettor is fitted. The choke valve 10 tends to produce vortices or turbulence in the air flow and this tends to cause the fuel supplied by the feeder 5, 6 to the wall of the chamber 2 to be prematurely removed before it is heated. This adversely affects the vaporization of the fuel and the formation of the air-fuel mixture. To avoid turbulence or vortices in the chamber 2, a stabilization conduit 16 is provided between the choke valve 10 and the fuel feeder 5, 6.

Abstract: An internal combustion engine is provided with an ion current sensor in the exhaust conduit. The sensor may be simply a spark plug across which is applied the vehicle battery voltage. The operation of the engine at various values of mixture composition yields characteristic curves for the ion current and for the fluctuations in the ion current as a function of the air number. These characteristic data are used to provide set point values against which the prevailing ion current is compared. If a set point value is exceeded, the fuel-air mixture is adjusted accordingly by an integral controller.

Abstract: The fuel-air mixture of an engine in a motor vehicle is controlled on the basis of a signal related to the fluctuations in the cyclic variations of the average combustion chamber pressure. This signal is derived indirectly from a sensor which monitors the rotational speed of engine members, e.g. the crankshaft. In order to provide closed-loop control, there is provided a reference value which is adapted continuously to changing engine speed. In addition, a correction of the reference signal is made to account for varying degrees of damping induced by changing inertial masses coupled to the engine, in particular the elements of the transmission connected between the engine and the vehicle. The correction for damping is made on the basis of signals related to the prevailing gear ratio either by direct indication of the gearshift lever position or by measuring the rotational speeds of the input and output shafts of the transmission.

Abstract: A method for determining adjustment values for a fuel supply device which supplies a fuel mixture to a fuel-burning engine for optimum performance by additionally influencing the preset adjustment values of the fuel supply device itself from values supplied by a storage means containing an engine performance log of adjustment values whereby said performance adjustment values are continuously changed and replaced by values which reflect instantaneous operating engine characteristics. Each replaced value forms the basis for computing a new value upon a change in engine operating characteristics.

Abstract: In order to enrich the fuel mixture fed to an internal combustion engine temporarily subsequent to engine braking, the invention proposes that engine braking is detected as the combination of a closed throttle and elevated engine speed. A detector for this condition supplies a signal to the fuel shut-off mechanism of a valve-control pulse generator. After engine braking, the counter is reset with the signal from the engine braking detector and counts engine-synchronous pulses. The counter contents are decoded and transformed into an analog signal which is used by the pulse generator for additional pulse extension to supply excess fuel to the engine for a limited period of time.

Abstract: The fluctuations of the rotational speed of the engine crankshaft are detected by two torsionally coupled inertial discs with fiducial markers. The movement of these markers past an inductive sensor provides a signal which is fed to a logical control circuit that controls the generation of a voltage which is characteristic of the actual crankshaft fluctuations. This actual voltage is amplified and rectified and compared with a set-point voltage generated by a set-point generator. The resulting signal is used to control an integrating circuit which may engage the fuel injection system of the exhaust gas recycling system of the engine to change the fuel-air mixture so as to return the actual voltage value to the set-point value.

Abstract: A fuel supply mechanism for an internal combustion engine includes a fuel-air mixture generator and an air bypass channel for conducting supplementary air to the mixture prior to delivery to the cylinders. The bypass channel has a valve which is coupled to the main throttle valve in the induction manifold. The coupling may be entirely mechanical or electro-mechanical. In addition, a controller which acts on the basis of engine information changes the degree of coupling between the main throttle and the bypass valve to admit more or less supplementary air, depending on the value of engine variables.

Abstract: A method for controlling the operation of an internal combustion engine based on dynamic engine stability (roughness) compares actual running data with an rpm-dependent but smooth reference signal to obtain a measure of the torque fluctuations of the engine. This measure is fed to a final control element which adjusts the ignition timing angle of the engine alone or in addition to the adjustment of other engine parameters, such as the fuel-air ratio and/or the exhaust gas recycle rate.

Abstract: A fuel metering system of an internal combustion engine is regulated by a data processor which has stored data prescribing the proper amount of fuel to be metered out for particular positions of the throttle valve and for particular values of the engine rpm. This preliminary adjustment is further refined by providing the data processor with feedback data concerning actual engine operating parameters, e.g. the exhaust gas composition, engine speed fluctuation and temperature. The feedback data is used by the data processor to override and further adjust the fuel quantity metered out to the engine.

Abstract: In the operation of an internal combustion engine, certain operating parameters, for example the length of fuel injection pulses, the ignition timing and the exhaust gas recycle rate can be adjusted on the basis of information related to state variables of the engine, for example the engine speed, the induction tube pressure, the air flow rate and the like. In particular, the injection pulse length may be determined from data stored in a memory and addressed by a pair of numbers related to the instantaneous values of engine speed and air flow rate. This type of open loop control is rapid and may be very exact but does not account for long-range changes in engine behavior due to wear, etc. For this reason, additional circuitry senses a further state variable, for example, the oxygen content of the exhaust gas or the engine roughness, and uses this information in a feedback loop to generate a correction signal which is then applied in a rate multiplier to the basic fuel injection datum.

Abstract: An electronic control circuit for operating an internal combustion engine near its lean running limit includes means for measuring the scattering bandwidth of the cyclic fluctuations of the combustion chamber pressure. This measurement is made indirectly by measuring the angular speed a rotating engine member, e.g., the crankshaft, and by forming and storing an appropriate analog signal. Circuitry is provided which supplies a nominal value of the scattering bandwidth which is compared electrically with the measured actual value. An appropriately processed difference signal is fed to a fuel injection controller which changes the fuel-air mixture to the desired ratio.

Abstract: The composition of the combustible mixture supplied to an internal combustion engine is controlled in dependence on the fluctuations in cylinder pressure which are monitored by sensing the fluctuations in the rotation of the engine crankshaft. These fluctuations are measured by comparison with a signal which simulates an engine running uniformly at the basic engine r.p.m. The signal which characterizes the r.p.m. fluctuations is compared with a nominal or command value and the resulting signal is used to control the mixture composition so as to maintain the fluctuations within predetermined limits.

Abstract: A method and apparatus for detecting cylinder malfunction by monitoring the actual rotational speed in an internal combustion engine, e.g. with an inductive transducer. This signal is compared in phase with pulses from a voltage controlled oscillator, the control voltage of which comes from an integrating circuit driven by the phase comparison signal in the manner of a phase-locked loop.The VCO pulses are used to clock a shift register and the actual pulses provide the data input for the shift register. Thus, the relative arrival time of the two pulse trains determines the contents of the shift register. Decoding circuitry is used to interrogate the shift register and to actuate an output device when the contents of the register indicate an unsymmetric periodicity, caused by cylinder malfunction.

Abstract: A fuel metering system of an internal combustion engine is controlled by an analog computer circuit which delivers injection pulses to actuate the fuel injection valves of the engine. The duration of these pulses is directly related to the amount of injected fuel and depends partly on the inherent electrical characteristics of the components of the analog computer circuit. The pulse duration also depends on the instantaneous values of at least two engine parameters, r.p.m. and throttle valve position, i.e., the degree of opening of the air inlet valve. The r.p.m. signal is sensed by an appropriate transducer and triggers a monostable multivibrator in the analog computer circuit while the throttle valve position is sensed by a potentiometer and defines the charging rate of a capacitor. The voltage on the capacitor influences the action of the monostable multivibrator which delivers the fuel injection pulse.

Abstract: An internal combustion engine is provided with an ion current sensor in the exhaust conduit. The sensor may be simply a spark plug across which is applied the vehicle battery voltage. The operation of the engine at various values of mixture composition yields characteristic curves for the ion current and for the fluctuations in the ion current as a function of the air number. These characteristic data are used to provide set point values against which the prevailing ion current is compared. If a set point value is exceeded, the fuel-air mixture is adjusted accordingly by an integral controller.