초록 ▼

A method of detecting spark plug fouling in an internal combustion engine is provided. The method comprises calculating an integration value of discharge current flowing between electrodes of a spark plug during a period of a spark discharge and judging if the calculated discharge current integratio

A method of detecting spark plug fouling in an internal combustion engine is provided. The method comprises calculating an integration value of discharge current flowing between electrodes of a spark plug during a period of a spark discharge and judging if the calculated discharge current integration value is smaller than an integration value criterion. The integration value criterion is set at such a value that can discriminate between normal discharge and interior jumping (i.e., jumping due to short circuit caused by fouling). When the calculated discharge current integration value is smaller than the integration value criterion, it is judged that the spark plug has been fouled. By this, it becomes possible to detect a spark plug fouling before the electrodes of the spark plug are short-circuited and disabled to generate spark discharge, i.e., before the spark plug is fouled to such an extent as to cause a misfire. An ignition system for detecting spark plug fouling is also provided.

대표청구항 ▼

A method of detecting spark plug fouling in an internal combustion engine is provided. The method comprises calculating an integration value of discharge current flowing between electrodes of a spark plug during a period of a spark discharge and judging if the calculated discharge current integratio

A method of detecting spark plug fouling in an internal combustion engine is provided. The method comprises calculating an integration value of discharge current flowing between electrodes of a spark plug during a period of a spark discharge and judging if the calculated discharge current integration value is smaller than an integration value criterion. The integration value criterion is set at such a value that can discriminate between normal discharge and interior jumping (i.e., jumping due to short circuit caused by fouling). When the calculated discharge current integration value is smaller than the integration value criterion, it is judged that the spark plug has been fouled. By this, it becomes possible to detect a spark plug fouling before the electrodes of the spark plug are short-circuited and disabled to generate spark discharge, i.e., before the spark plug is fouled to such an extent as to cause a misfire. An ignition system for detecting spark plug fouling is also provided. ion and a magnitude of said force, said method comprising the steps of: providing a capacitance element including a deviation electrode and a fixed electrode, said deviation electrode being located at a position which deviates along with said working body and said fixed electrode being fixed to said substrate so as to face said deviation electrode, and said capacitance element being arranged so that an electrode distance of said capacitance element changes when said working body is deviated in an X-axis direction of said XYZ three-dimensional coordinate system; applying a voltage between said deviation electrode and said fixed electrode so that Coulomb force is produced which causes spatial deviation of said working body in said X-axis direction; detecting an electric signal transformed by said transducer while said spatial deviation is caused by applying said voltage; and testing an operation of said sensor with respect to said X-axis direction based on a relationship between said applied voltage and said detected electric signal. 2. A method of testing a sensor, said sensor comprising: a substrate arranged along an XY-plane of an XYZ three-dimensional coordinate system; a working body receiving a force and located adjacent to said substrate with a predetermined distance; a flexible member supporting said working body at a periphery thereof so that said working body is suspended and spatial deviation of said working body is produced by applying said force thereto; a fixing member fixing said flexible member to said substrate; and a transducer for transforming said spatial deviation into an electric signal that indicates a direction and a magnitude of said force, said method comprising the steps of: providing a capacitance element including a deviation electrode and a fixed electrode, said deviation electrode being located at a position which deviates along with said working body and said fixed electrode being fixed to said substrate so as to face said deviation electrode, and said capacitance element being arranged so that an electrode distance of said capacitance element changes when said working body is deviated in a Z-axis direction of said XYZ three-dimensional coordinate system; applying a voltage between said deviation electrode and said fixed electrode so that Coulomb force is produced which causes spatial deviation of said working body in said Z-axis direction; detecting an electric signal transformed by said transducer while said spatial deviation is caused by applying said voltage; and testing an operation of said sensor with respect to said Z-axis direction based on a relationship between said applied voltage and said detected electric signal. 3. A method of testing a sensor, said sensor comprising: a substrate arranged along an XY-plane of an XYZ three-dimensional coordinate system; a working body receiving a force and located adjacent to said substrate with a predetermined distance; a flexible member supporting said working body at a periphery thereof so that said working body is suspended and spatial deviation of said working body is produced by applying said force thereto; a fixing member fixing said flexible member to said substrate; and a transducer for transforming said spatial deviation into an electric signal that indicates a direction and a magnitude of said force, said method comprising the steps of: providing a capacitance element including a deviation electrode and a fixed electrode, said deviation electrode being located at a position which deviates along with said working body and said fixed electrode being fixed to said substrate so as to face said deviation electrode, and said capacitance element being arranged so that an electrode distance of said capacitance element changes when said working body is deviated in an X-axis direction and a Z-axis direction of said XYZ three-dimensional coordinate system; applying a first voltage between said deviation electrode an