Abstract: A rotational position detector for detecting the position of the crankshaft of a multi-cylinder internal combustion engine is disclosed. A signal generator generates pulses whose leading and trailing edges correspond to the first and second rotational positions of the crankshaft with respect to the respective cylinders. The first and the second rotational positions are at 75 degrees BTDC and 5 degrees BTDC with respect to respective cylinders; however, the second rotational position of the crankshaft with respect to a particular cylinder (cylinder No. 1) is displaced to the retarding side by 10 degrees, i.e. to 5 degrees ATDC. Thus, those pulses which correspond to cylinder No. 1 is identified as follows: first, the duty ratio t/T of the pulse width t to the period T between the leading edges of the two successive pulses is calculated; then, the duty ratio t/T is compared with a predetermined reference level to identify the pulses corresponding to cylinder No. 1.

Abstract: An ignition control system for an internal combustion engine capable of determining appropriate ignition timing in an exact manner without employing a crank angle sensor so as to optimize the combustion of the mixture in the engine cylinders. To this end, a reference ignition timing is first determined based on the operating conditions (e.g., load condition) of the engine, and the internal pressure in the engine cylinder is sensed so that the state of combustion of a mixture in the engine cylinder is detected based on the engine cylinder internal pressure thus sensed. The reference ignition timing is then modified to provide an optimum ignition timing by an amount of modification which is calculated by using a peak point in time of the cylinder internal pressure at which a peak of combustion pressure in the engine cylinder takes place.

Abstract: This invention provides a controller for controlling the combustion of an internal combustion engine. The controller comprises pressure sensors for detecting the pressure in a set of cylinders. The detected pressure profile in the cylinders is used to determine the combustion parameters, based on which the drive control parameters are determined. The combustion of the engine is normally controlled with those drive control parameters while the control is performed by means of predetermined parameters in the event of no combustion occurring. In determining the combustion parameters, the controller in accordance with this invention calibrates the pressure profile detected by the pressure sensor to eliminate the modulus and the offset of the pressure sensor from the pressure profile. The modulus and the offset are renewed on a proper basis to make up for the drawback that the modulus and the offset fluctuate in response to changes in temperature.

Abstract: The present invention relates to a pressure detecting apparatus which detects the peak of combustion pressure in a cylinder of an internal combustion engine and the timing of that peak. The apparatus according to the present invention can be constructed in two alternative ways. That is, in one way, once stored data of combustion pressure in the cylinder is read out in reverse order, thus the difference between the read-out data and the data of combustion pressure in the cylinder is obtained, and the peak of combustion pressure in the cylinder and the timing of the peak are detected in accordance with the difference. In another way, the inflection points of the differentiated result of the data of combustion pressure in the cylinder are detected, and the peak of combustion pressure and the timing of the peak are detected in accordance with the inflection points.

Abstract: An air-to-fuel ratio control device for an internal combustion engine is disclosed, which comprises a pressure sensor for detecting the pressure P within a cylinder of the engine, and means for computing an actual value of the ratio (dP/d.theta.)max/Pmax, wherein (dP/d.theta.)max is the maximum rate of change in pressure P within the cylinder with respect to the crank angle .theta. and Pmax is the maximum pressure in the cylinder during a predetermined interval in a cycle of the cylinder. A target value of the ratio (dP/d.theta.)max/Pmax is obtained by converting the optimum air-to-fuel ratio corresponding to the operating condition of the engine, the conversion being effected by means of a relationship established between the values of the air-to-fuel ratio and those of the ratio (dP/d.theta.)max/Pmax. A control element controls the amount of injected fuel to reduce the deviation of the actual value of the ratio (dP/d.theta.)max/Pmax with respect to the target value thereof.

Abstract: When an internal combustion engine is accelerated at high rate, a feedback control constant for an ignition current supply period is changed to control a ratio of a time period for which a primary current of the ignition coil is at a predetermined value to an ignition period to a predetermined value to thereby maintain a sufficient cut off current even at such high rate acceleration of the engine.

Abstract: An ignition control device for an internal combustion engine includes a digital control circuit which functions to reduce gradually a current flowing through a primary side of an ignition coil when a current supply to the primary side of the ignition coil continues for a time longer than a normal current supply period, to thereby prevent undesired spark discharge from occurring in an ignition plug.

Abstract: The present invention utilizes, selectively, a first signal formed in a first section of an ignition period composed of the first section and a second section with a predetermined ratio or a second signal formed in the second section according to a ratio of a time in which a current is supplied to an ignition coil to the ignition time period to obtain a start time of current supply to the coil means.

Abstract: An ignition control system for an internal combustion engine has means for determining the maximum energizing time of an ignition coil from a signal synchronized with the ignition timing of the engine and controlling the period that the energizing current reaches a predetermined value to a predetermined value, thereby determining the maximum energizing time of the ignition coil from the signal synchronized with the ignition timing of the engine, detecting the energizing current of the ignition coil, and variably setting the maximum closed-circuit rate of energizing the ignition coil according to the operating state of the engine and a battery voltage.

Abstract: An ignition control system for an internal combustion engine has an oscillator for generating a clock signal, ignition timing signal generator means for generating an ignition timing signal synchronized with the ignition timing of the engine, a defect detector for detecting the defect of the oscillator, a control circuit for calculating the energizing timing of an ignition coil from the ignition timing signal when the oscillator is normal, and a switching circuit for disconnecting the output of the control circuit when the oscillator is defective to lead the ignition timing signal to an igniter, thereby switching the switching circuit to the output side of the control circuit by the output of the defect detector when the oscillator is normal to calculate the energizing timing of the ignition coil by the control circuit from the ignition timing signal to lead it to the igniter, and thereby switching the switching circuit by the defect detector when the oscillator is defective to lead the ignition timing signal

Abstract: A knock deriving apparatus for an internal combustion engine wherein only a knock signal is precisely derived from the output signal of a knock sensor including a noise signal component by the provision of first and second frequency filters serially connected to the knock sensor. The first frequency filter has a band width wider than that of the second frequency filter to cover a resonant noise. The resultant band width by the series combination of both filters is set to just cover a frequency band where knocks occur. The output of the first frequency filter is converted to a comparative reference signal which is compared in a comparator with the output of the second filter, thereby deriving a stable knock signal.

Abstract: An ignition timing control apparatus for an internal combustion engine in which the reference ignition timing of the engine is changed over or displaced according to the detected result of the occurrence of knocks owing to the kind of fuel being used for the engine. In changing over the ignition timing characteristic, the change-over magnitude between the reference ignition timings for premium and regular gasolines is determined according to an operating condition of the engine whereby a knock control is made based on the determined change-over magnitude. In displacing the ignition timing when a mixture of premium and regular gasolines is being used, the displacement magnitude for either of the reference ignition timings for premium and regular gasolines is determined according to an operating condition of the engine whereby a knock control is made based on the determined displacement magnitude.

Abstract: A control apparatus for an internal combustion engine operable on fuels of different octane numbers implements automatic control when the engine knocks to correct the ignition timing preset in accordance with the octane number of the fuel in use to the retarded side so that the engine operates under the optimum condition. This automatic control enhances engine output and drivability, prevents engine fracture and saves fuel cost.

Abstract: An ignition timing control apparatus for an internal combustion engine in which the reference ignition timing of the engine is changed over or displaced according to the detected result of the occurrence of knocks owing to the kind of fuel being used for the engine. Either in the change-over determination or the displacement magnitude determination, the change-over magnitude of the reference ignition timing is initialized at a predetermined retard angle.

Abstract: A control apparatus for an internal combustion engine in which the condition of the operating parameters of the engine is changed over according to the detected result of the occurrence of knocks only when the engine lies in a predetermined operating region. The operating parameters include an ignition timing, a supercharging pressure, a compression ratio, and an air/fuel ratio. The knocks of the engine are integrated and compared with a threshold level to determine which of premium or regular gasoline is being used. In this determination, if the operating region lies in said predetermined operating region, the condition of the operating parameters is changed over. The predetermined operating region is defined by a load information and a speed information of the engine.

Abstract: An ignition timing control apparatus for an internal combustion engine capable of using as a fuel a regular (low-octane) gasoline, a premium (high-octane) gasoline. The engine produces knocks when the ignition timing is advanced beyond a reference ignition timing determined as a function of the type of gasoline being used. This advance ignition timing control apparatus detects the knocks, and provides as an output a signal according to the occurrence rate of the knocks which essentially indicates the type of gasoline in use. By means of this signal, this ignition timing control apparatus changes over one reference ignition timing adapted for premium gasoline to the other reference ignition timing adapted for regular gasoline to retard the current ignition timing. At the same time, in a predetermined operating region of the engine, the ignition timing can be fixed in the retard or advance mode angle, whereby a desirable ignition timing for an engine is provided so as to improve the performance of the engine.

Abstract: A control apparatus for an internal combustion engine capable of using as a fuel a regular (low-octane) gasoline, a premium (high-octane) gasoline, or a mixture of both type of gasolines. The engine produces knocks when the ignition timing is advanced beyond a reference ignition timing determined as a function of the type of gasoline being used. This ignition timing control apparatus detects the knocks, and provides as an output therefrom a signal according to the occurrence rate of the knocks which essentially indicates the type of gasoline in use. By means of this signal, this ignition timing control apparatus continuously displaces the reference ignition timing in the direction of retard angle by using a proportion factor calculator and an interpolator. At the same time, the displaced reference ignition timing is corrected by the detected knock signals on a real time basis.

Abstract: An ignition timing control apparatus for an internal combustion engine capable of using as a fuel a regular (low-octane) gasoline, a premium (high-octane) gasoline, or a mixture of both type of gasolines. The engine produces knocks when the ignition timing is advanced beyond a reference ignition timing determined as a function of the type of gasoline being used. This advance ignition timing control apparatus detects the knocks, and provides as an output therefrom a signal according to the occurrence rate of the knocks which essentially indicates the type of gasoline in use. By means of this signal, this ignition timing control apparatus continuously displaces the reference ignition timing in the direction of retard angle by using a proportion factor calculator and an interpolator. At the same time, the displaced reference ignition timing is corrected by the detected knock signals on a real time basis. The combined ignition timing signal serves to energize an ignition coil to suppress the occurrence of knocks.

Abstract: An ignition timing control apparatus for an internal combustion engine capable of using as a fuel a regular (low-octane) gasoline, a premium (high-octane) gasoline, or a mixture of both type of gasolines. The engine produces knocks when the ignition timing is advanced beyond a reference ignition timing determined as a function of the type of gasoline being used. This ignition timing control apparatus detects the knocks, and provides as an output therefrom a signal according to the occurrence rate of the knocks which essentially indicates the type of gasoline in use. By means of this signal, this ignition timing control apparatus continuously displaces the reference ignition timing in the direction of retard angle by using a proportion factor calculator and an interpolator. At the same time, the displaced reference ignition timing is corrected by the detected knock signals on a real time basis. The combined ignition timing signal serves to energize an ignition coil to suppress the occurrence of knocks.

Abstract: An ignition timing control device for an internal combustion engine including a knocking sensor for detecting knocking of the engine, a reference voltage generator for generating a reference voltage dependent on the level of an output signal from the knocking sensor, a comparator for comparing the output signal from the knocking sensor with the reference voltage and for generating a train of pulses dependent on an amplitude of knocking as produced, an integrator for integrating an output signal from the comparator in an analog or digital manner, ignition timing controller means responsive to the level of the output voltage from said integrator for controlling the ignition timing of the internal combustion engine, and control means triggerable by the output of said comparator for increasing a variation speed in the output signal level of said integrator during no knocking as time elapses, whereby a speed at which ignition timing of the internal combustion engine is advanced, is increased as time elapses.