Abstract: A device for discriminating cylinders in an internal combustion engine includes a rotational fluctuation detecting means for detecting a rotational fluctuation in an internal combustion engine on the basis of a rotary signal, cylinder discriminating means for discriminating a cylinder on the basis of the time interval between reference angular positions, inhibiting means for inhibiting cylinder discrimination by said cylinder discrimination means when the rotational fluctuation detecting means detects a rotational fluctuation, and cylinder predicting means for predicting and discriminating a cylinder from the past cylinder discrimination result when said inhibiting means inhibits cylinder discrimination by the said cylinder discriminating means. Thus, the cylinder discriminating device for an internal combustion engine with no error irrespectively of the running state of the engine.

Abstract: Misfiring in an engine cylinder can be detected based on the pressure therein as sensed by a pressure sensor with a high degree of reliability at any time even if the output signal of the pressure sensor contains an offset component superposed on a pressure component representative of the actual cylinder pressure. In one form, the pressure sensor output is differentiated to eliminate the influence of the offset component and then processed to generate a power stroke pressure information signal in the form of the time of a pressure-change peak in the differentiated pressure sensor output or an integrated value of the differentiated output, which is then compared with a threshold so as to determine whether misfiring took place in the cylinder.

Abstract: An electronic circuit equipment including a substantially box-shaped case body 30 for defining a sealed interior space therein and an electronic circuit board 11 having a plurality of electronic components 12 mounted thereon. The case body comprises a pair of cup-shaped sections 30a clamped together at their opposite ends, and sandwiching between them the circuit board, surrounded and sealingly enclosed by a gas-impermeable flexible sheet 32. A vent hole 20 is provided in one of the sections 30a such that the sheet 32 flexes to absorb pressure fluctuations, and prevents the circuit board from bending.

Abstract: A ignition coil device for an internal combustion engine includes: a tubular high tension terminal which is electrically connected to a secondary output terminal of an ignition coil and has a side face portion, and one end of which is open; a first member accommodated in the tubular portion of the high tension terminal and fixed in the side face portion; a coil-shaped electrically conductive spring member which is accommodated in the tubular portion of the high tension terminal, and one end portion of which is wound around the first member a plurality of times in contact therewith; a second member accommodated in the tubular portion of the high tension terminal and having a shaft portion around which another end portion of the electrically conductive spring member is wound a plurality of times in contact therewith and a contacting portion which is electrically connected to a conductor of an ignition cable in contact therewith; and a retaining portion for retaining the conductor in a state in which the conduct

Abstract: Misfiring in an engine cylinder can be detected based on the pressure therein as sensed by a pressure sensor with a high degree of reliability at any time even if the output signal of the pressure sensor contains an offset component superposed on a pressure component representative of the actual cylinder pressure. In one form, the pressure sensor output is differentiated to eliminate the influence of the offset component and then processed to generate a power stroke pressure information signal in the form of the time of a pressure-change peak in the differentiated pressure sensor output or an integrated value of the differentiated output, which is then compared with a threshold so as to determine whether misfiring took place in the cylinder.

Abstract: An electronic circuit equipment including a substantially box-shaped case main body (10) for defining a sealed interior space therein and an electronic circuit board (11) having a plurality of electronic components (12) thereon. The case main body (10) comprises a case body (13) and a flat plate-shaped lid (17) positioned properly with respect to the case body (13) to seal the interior space. A vent hole (20) is formed in the bottom wall of the case body (13) for communicating the interior of the case body (13) with ambient atmosphere. A cover member is attached to the case body (13) to cover the vent hole hermetically. By using a cover member, the interior space of the case body (13) is sealed for protecting electronic components (12) on the electronic circuit board (11) from moisture and rainwater and, for absorbing a pressure fluctuation therein. A mounting flange extends from the case body and surrounds the vent hole. The cover member is a flexible diaphragm with a circumferential bulge.

Abstract: An apparatus for controlling an internal combustion engine that automatically corrects an error of a reference position to prevent an erroneous calculation of a controlled-parameter so as to accurately control the internal combustion engine, the apparatus for controlling an internal combustion engine having a period measuring section for measuring a period of a plurality of reference-position areas and a period of a plurality of areas corresponding to cylinders of a reference-position signal, an angular error detection section for detecting an angular error in each reference-position area in accordance with the period of the reference-position areas and the period of the areas corresponding to the cylinders and an error discrimination section that discriminates validity of the angular error to generate a final angular error, wherein a timer control section corrects the controlled-parameter in accordance with the final angular error, and a control time setting section corrects a time controlled by the timer in

Abstract: An internal combustion engine control device improving the combustion state without increasing the cost.

Abstract: A control apparatus for a marine engine capable of effectively suppressing a great variation in the rotational speed of the engine due to a great variation in an intake air pressure particularly when the engine is trolling. In one form, an air/fuel ratio of a mixture supplied to the engine is made constant to maintain engine output power at a constant level. In another form, the intake air pressure, based on which the engine is controlled, is averaged in such a manner as to reduce a variation in the engine rotational speed by using a greater averaging coefficient during trolling than at other times. In a further form, if a variation in the intake air pressure is less than a predetermined value, the intake air pressure is used controlling the engine, whereas if otherwise, another engine operating parameter such as an opening degree of a throttle valve is used instead of the intake air pressure.

Abstract: An apparatus for deciding occurrence of misfire in an internal combustion engine comprises an angle sensor for generating a reference position signal corresponding to a predetermined crank angle of an engine cylinder, a sensor for detecting a running state of the engine, an ion current detector for detecting combustion state in the engine cylinder, a control parameter setting means for setting a control parameter of the engine on the basis of the reference position signal and the running state, a misfire detector for generating a misfire detection signal indicative of occurrence of misfire in the engine on the basis of detection output of the ion current detector, a misfire interval counter for measuring as a misfire interval an interval at which the misfire detection signal is generated, a misfire decision means for generating a misfire decision signal when the misfire interval becomes shorter than a predetermined interval.

Abstract: Misfiring in an engine cylinder can be detected based on the pressure therein as sensed by a pressure sensor with a high degree of reliability at any time even if the output signal of the pressure sensor contains an offset component superposed on a pressure component representative of the actual cylinder pressure. In one form, the pressure sensor output is differentiated to eliminate the influence of the offset component and then processed to generate a power stroke pressure information signal in the form of the time of a pressure-change peak in the differentiated pressure sensor output or an integrated value of the differentiated output, which is then compared with a threshold so as to determine whether misfiring took place in the cylinder.

Abstract: An apparatus for controlling operation of an internal combustion engine including a multiplicity of cylinders. The apparatus comprises a control means for detecting speedily reference positions for control of the individual cylinders with high reliability. In the control means, a reference position signal generating means for generating a reference position signal containing six equiinterval rectangular pulses each having a duty cycle of 1/2 during a single rotation of a crank shaft is provided in combination with a cylinder identification signal generating means for generating a plurality of different-interval rectangular pulses during a rotation of a shaft interlocked to the cam shaft so that a series of four successive signal levels of the different-interval rectangular pulses sampled at one edges of the equi-interval rectangular pulses differ from one to another succeeding series. The series of the signal levels thus fetched are stored in a signal level data storage means.

Abstract: An apparatus for controlling operation of an internal combustion engine on the basis of a plurality of cylinder identification signals and a reference position signal includes a control means for making it possible to continue the engine operation control even when one of the above signals suffers from abnormality. The control means includes a first decision means for making decision as to whether or not the individual cylinder identification signals are normal, and a first back-up means for controlling the engine on the basis of other cylinder identification signal(s) when one of said cylinder identification signals is decided to be not normal.

Abstract: Misfiring in a cylinder of an engine can be detected with high reliability using a statistical treatment even if the level of ion current generated by a spark plug upon ignition thereof is affected by noise. An ion current, which is generated when a spark plug for a cylinder discharges, is detected to provide a corresponding voltage which is then integrated or peak held to produce a current component signal which is generated for a predetermined time from the time of discharge of the spark plug. The current component signal is used as misfiring information and compared with a prescribed threshold so as to determine whether there is misfiring in the cylinder. Misfirings thus detected are counted so as to evaluate the state or extent of misfiring in the cylinder. If the state of misfiring is serious, the fuel supply to the cylinder is stopped.

Abstract: A control apparatus for a marine engine capable of effectively suppressing a great variation in the rotational speed of the engine due to a great variation in an intake air pressure particularly when the engine is trolling. In one form, an air/fuel ratio of a mixture supplied to the engine is made constant to maintain engine output power at a constant level. In another form, the intake air pressure, based on which the engine is controlled, is averaged in such a manner as to reduce a variation in the engine rotational speed by using a greater averaging coefficient during trolling than at other times. In a further form, if a variation in the intake air pressure is less than a predetermined value, the intake air pressure is used for controlling the engine, whereas if otherwise, another engine operating parameter such as an opening degree of a throttle valve is used instead of the intake air pressure.

Abstract: An engine control apparatus can significantly improve reliability in misfire detection by preventing erroneous detection of the level of an ion current due to noise superposition. An angular position detector generates a reference position signal representative of a predetermined crank angle of each engine cylinder in synchronism with the rotation of an internal combustion engine. Sensors detect an operating state of the engine. An ion current detector detects an ion current in at least one of the engine cylinders. An engine control parameter setter sets a control parameter for the engine in accordance with the reference position signal and the engine operating state. A misfire detector generates a misfire detection signal indicative of occurrence of misfiring in the at least one engine cylinder on the basis of a value of the ion current. The control parameter setter corrects the control parameter on the basis of the misfire detection signal.

Abstract: An apparatus for controlling operation of a four-cycle internal combustion engine including an odd number of cylinders comprises a reference position signal generator 1A driven by the crank shaft whose output includes a number of constant-interval pulses generated periodically at a predetermined constant time interval during a single rotation of the crank shaft, such number being equal to N times the number of cylinders, a cylinder identification signal generator 2A driven by the cam shaft interlocked to and at half the speed of the crank shaft, whose output includes a number of different-interval pulses corresponding to the number of cylinders, a synthesized reference position signal generator 33 for generating a signal T2 by dividing the frequency of the reference position signal by 1/2N, a cylinder discriminator 34, 31A for generating a cylinder discrimination signal F, and a timing control unit 32.

Abstract: An internal combustion engine control apparatus for performing the timing control such as ignition and fuel injection timing control with high accuracy even in a transient operation state such as acceleration or deceleration. A ratio between a first interval period extending from a first reference position to a second reference position and a second interval period extending from a second reference position to the first reference position is determined. A correcting coefficient is calculated on the basis of the ratio. By using this correcting coefficient, the predicted reference position period is calculated, on the basis of which the timing control is performed.

Abstract: An engine control apparatus capable of detecting occurrence of abnormality in the ignition coil with high reliability. The apparatus includes an initial detection level hold device for holding an initial level (In) of a detected ion current value I, and an ignition coil diagnosis device for generating an abnormality decision signal of the ignition coil in dependence on the initial level of the ion current. By positively utilizing noise produced in an initial phase of the ignition cycle instead of eliminating it, the abnormality decision signal is generated, on the basis of which an appropriate engine protection measure is taken.

Abstract: A knock suppression apparatus for an internal combustion engine includes a peak value sensor that senses a peak value of a knock signal indicating knocking of an engine. An analog-digital converter repeatedly converts the peak value into a digital value at prescribed intervals. The most recent digital peak value from the analog-digital converter is stored in a memory and used by a lag angle calculator to calculate a lag angle for suppressing knocking. The ignition timing of the engine is controlled according to a basic ignition timing and the lag angle. Because the analog-digital converter is constantly performing conversion, the ignition timing can be immediately adjusted to compensate for knocking.