Volkswagen Ag

Klaus Stamm

Istvan Geiger

Heinz Theuerkauf

Siegbert Graf Vom Hagen

Reinhard Bruning

Manfred Meyer

Electronic ignition system for an internal combustion engine

A method and device for adjusting the timing of an internal combustion engine in response to knocking are provided. In the method, knocking signals are generated when the engine knocks and the timing is too far advanced. First correctional signals are generated in response to the knocking signals and adjust at one speed range one of several control curves. Second correctional signals are generated from the first correctional signals to adjust the control curves at the remaining speed ranges. The timing of the engine is retarded in response to the adjusted control curves until the knocking disappears. The system for adjusting the ignition timing comprises a knocking sensor, an ignition computer storing several control curves and generating ignition timing correction signals, a counter for generating signals to the ignition computer to change the control curves, a logic unit for receiving signals from the ignition computer and the knocking sensor and generating correction signals, and an interconnection device for adjusting the timing of the internal combustion engine in response to the ignition correction signals.

Method and system for operation of a spark-ignited internal combustion

The ignition timing of a spark-ignited internal combustion engine is controlled to have a stabilized idle speed which is approximately equal to a desired idle speed. In accordance with the invention the engine is supplied with a fuel-air mixture which has a high air ratio, exceeding the air ratio corresponding to maximum mean indicated pressure and hence maximum torque. The air ratio is in a range wherein an increased air ratio corresponds to decreased mean indicated pressure and consequently decreased torque. According to the invention, the ignition timing of the engine is controlled to linearly advance the timing from a nominal retarded condition in proposition to change in engine speed below the desired speed. The timing advance has the same ratio to engine speed change as the ratio of nominal ignition pulse spacing to the desired engine idle speed.

Method and apparatus for controlling the idling operation of a

A method for operating an internal combustion engine under varying load conditions includes different controls which are used in first, second and third load ranges of the engine. In the first, lowest load range, including idle operation, a constant lean fuel-air ratio and constant mixture volume are supplied to the engine while the ignition timing is varied to provide a more advanced timing with increased engine load. In the second, intermediate load range, the lean fuel-air ratio is again maintained constant, the ignition timing corresponding to the most advanced ignition timing of the first range is maintained constant, and the mixture volume is varied from the volume corresponding to the first range to a higher volume with increased engine load. In the third, highest range of engine load, the mixture volume is maintained constant, the ignition timing is varied only as required to prevent knocking of the engine, and the fuel-air ratio is varied to supply a richer mixture with increased engine load. In one embodiment of the invention, the fuel-air ratio and ignition timing are controlled by the use of an electronic control circuit which responds to signals representative of a control lever position and the engine speed. The mixture volume is controlled by a conventional throttle flap which is linked in a special manner to the control lever.

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Wolfsburg, Germany

Klaus Stamm