Abstract: An in-cylinder pressure detection device which is capable of ensuring stable detection accuracy irrespective of tightening torque applied in mounting the in-cylinder pressure detection device and thermal expansion of component parts of the same. A housing 21 has a top wall 22a and a bottom wall 22b opposed to each other, and is screwed into the body of an internal combustion engine. An inner member 24 extends through the housing 21 such that one end thereof projects into a cylinder C, and has a flange part 24b accommodated in the housing 21. A first piezoelectric element 11c is accommodated in the housing 21 and sandwiched between the bottom wall 22b and the flange part 24b in a preloaded state, for outputting a first detection signal q1 according to the in-cylinder pressure transmitted via the inner member 24.

Abstract: An in-cylinder pressure detection device which is capable of ensuring stable detection accuracy irrespective of tightening torque applied in mounting the in-cylinder pressure detection device and thermal expansion of component parts of the same. A housing 21 has a top wall 22a and a bottom wall 22b opposed to each other, and is screwed into the body of an internal combustion engine. An inner member 24 extends through the housing 21 such that one end thereof projects into a cylinder C, and has a flange part 24b accommodated in the housing 21. A first piezoelectric element 11c is accommodated in the housing 21 and sandwiched between the bottom wall 22b and the flange part 24b in a preloaded state, for outputting a first detection signal q1 according to the in-cylinder pressure transmitted via the inner member 24.

Abstract: A misfire-detecting system for an internal combustion engine having a plurality of cylinders. A rotational speed of the engine is detected and a rotational speed signal indicative of the detected rotational speed of the engine is output. The rotational speed signal is filtered. Occurrence of a misfire in the engine is determined based on the filtered rotational speed signal.

Abstract: A misfire-detecting system for an internal combustion engine detects a value of the sparking voltage generated by the igniting device after generation of the ignition command signal, determines the duration of a discharge of a spark plug, based upon the detected sparking voltage, and determines whether or not a misfire has occurred in the engine, based upon the determined duration of the discharge. For example, the misfire-detecting system measures the duration of the discharge from the time of generation of the ignition command signal, based upon the detected sparking voltage, compares the measured duration of the discharge with a predetermined time period. When the measured duration is shorter than the predetermined time period, it is determined that a misfire has occurred in the engine.

Abstract: In equipment for recognizing misfire in an internal combustion engine, a first voltage waveform is obtained at an intermediate point (A) between a high impedance element (41) and a low impedance element (42). The first voltage waveform has a capacitive discharge component and an inductive discharge component during the spark and a voltage component after completion of the spark. The first voltage waveform is inversely amplified by a comparator (51) and divided by a shunt circuit (52) to obtain a second voltage waveform. In an integration circuit (53), a condenser (C1) is electrically charged by an output voltage from the comparator (51) to obtain a third voltage waveform. The second voltage waveform and the third voltage are compared by a comparator (54) to generate an output pulse.

Abstract: A misfire-detecting system for an internal combustion engine detects a value of sparking voltage generated by the igniting device of the engine after generation of an ignition command signal, compares the value of the detected sparking voltage with a predetermined value, and determines whether or not a misfire has occurred in the engine, based upon the result of the comparison. The misfire-detecting system can discriminate between a misfire attributable to the fuel supply system of the engine and one attributable to the ignition system of the engine, from a detected peak value of the sparking voltage.

Abstract: A misfire-detecting system for an internal combustion engine detects a value of sparking voltage generated after generation of an ignition command signal, compares the detected value of sparking voltage with a predetermined voltage value, and determines whether or not a misfire has occurred in the engine, based upon results of the comparison. The determination as to occurrence of the misfire is effected, based upon results of the comparison between the detected value of the sparking voltage and the predetermined voltage value, obtained within a previously set limited comparison period.

Abstract: A misfire-detecting system detects a misfire occurring in an internal combustion engine in such a manner that a value of discharge current is detected when sparking voltage is generated in response to an ignition command signal, the detected value of discharge current is compared with a predetermined current value, and it is determined that a misfire has occurred when a time period over which the detected discharge current value after generation of the ignition command signal is above the predetermined current value is shorter than a predetermined time period.

Abstract: A misfire-detecting system detects a misfire occurring in an internal combustion engine. A value of sparking voltage after generation of an ignition command signal indicative of ignition timing is detected and compared with a predetermined voltage value, and it is determines based upon the results of the comparison whether or not a misfire has occurred in the engine. The determination as to occurrence of the misfire is based upon at least one of a time period over which the detected value of the sparking voltage exceeds the predetermined voltage value, and an area of a portion of detected values of the sparking voltage exceeding the predetermined voltage value.