Ignition system for internal combustion engines with misfiring detection by comparing the same ignition coil
AssigneeRobert Bosch GmbH
InventorsKarl-Heinz Kugler, Karlheinz Riedel
Life of this patent
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Abstract
An ignition system is provided for internal combustion engines for detecting combustion misfirings. The ignition system of an internal combustion engine detects the spark voltage transformed on to the primary side of a double spark coil for evaluating the ignition spark duration and/or the ignition spark voltage so as to allow a comparison to be made with limit values for a correct ignition. The limit values for a correct ignition are determined from the measured variables of a reference ignition. The reference ignition is the ignition which is triggered by the energy potential of the same ignition coil.
Claims11
An ignition system for controlling ignition during a first combustion cycle of an internal combustion engine, comprising:
- at least one ignition coil having a primary winding and a secondary winding, the secondary winding having a high-voltage end;
- a spark plug connected to the high-voltage end of the secondary winding;
- a control switch connected in series with the primary winding, a tap being attached between the primary winding and the control switch for detecting first and second spark voltages transformed onto the primary winding, the first spark voltage corresponding to the first combustion cycle, the second spark voltage corresponding to a second combustion cycle prior to the first combustion cycle;
- an evaluation circuit coupled to the primary winding for determining at least one limit value indicating a correct combustion of the internal combustion engine as a function of the detected second spark voltage, and for comparing the detected first spark voltage with the at least one limit value.
An ignition system for an internal combustion engine, comprising:
- a double spark coil having a primary winding and a secondary winding, the secondary winding having a first end and a second end;
- a first spark plug connected to the first end;
- a second spark plug connected to the second end;
- a control switch connected in series with the primary winding, a tap being attached between the primary winding and the control switch for detecting a spark voltage transformed onto the primary winding;
- an evaluation circuit coupled to the primary winding for comparing the detected spark voltage with at least one limit value indicating a correct combustion of the internal combustion engine;
- and
- wherein the at least one limit value is determined as a function of the detected spark voltage from at least one preceding combustion cycle.
A method for determining a correct combustion of an internal combustion system, the internal combustion engine having at least one ignition coil coupled to at least one spark plug, the method comprising the steps of:
- determining a first spark voltage across the at least one spark plug and a first spark duration of the at least one spark plug;
- determining a second spark voltage across the at least one spark plug and a second spark duration of the at least one spark plug;
- comparing the first spark voltage with the second spark voltage;
- comparing the first spark duration with the second spark duration;
- if the second spark voltage is within a first predetermined tolerance factor of the first spark voltage and the second spark duration is within a second predetermined tolerance factor of the first spark duration, providing a first signal indicating the correct combustion of the internal combustion engine;
- and
- if at least one of the second spark voltage differs from the first spark voltage by an amount greater than the first predetermined tolerance factor and the second spark duration differs from the first spark duration by an amount greater than the second predetermined tolerance factor, providing a second signal indicating a faulty combustion of the internal combustion engine.
Dependencies are inferred from the claim text.