Abstract: An internal combustion engine has an exhaust system and an oxygen sensor fitted to the exhaust system including a sensor element and an electrically powered heater for heating the sensor element. A method is disclosed for controlling the air/fuel ratio of the air-fuel mixture supplied to the engine, by, when the voltage of the power supply to the heater has dropped below a first predetermined value and thereafter has remained below a second predetermined value higher than the first predetermined value for longer than a predetermined time period, controlling the air/fuel ratio according to engine operational parameters by an open loop form of control with no account being taken of the output signal of the oxygen sensor, and otherwise controlling the air/fuel ratio according to these engine operational parameters by a closed loop form of control taking into account the output signal of the oxygen sensor so as to obtain an optimum air/fuel ratio for the engine by a feedback control process.

Abstract: An internal combustion engine has an exhaust system and an oxygen sensor fitted to the exhaust system including a sensor element and an electrically powered heater for heating it. The power supplied to the heater is controlled by determining a target value for it according to operational parameters of the engine, and by controlling the mean power in a time interval as follows: the voltage applied to the heater and the current flowing through it are detected, an intermittent voltage is supplied to the heater, and the duty ratio of the intermittent voltage is controlled so that the product of the heater voltage and the heater current is substantially equal to the target power, with the detection of the voltage supplied to the heater synchronized with the energization of the heater. A system is also described for implementing this method.

Abstract: The ignition timing of an internal combustion engine is controlled to a predetermined fixed value, not only during starting but also until the engine has rotated by a predetermined number of rotations after starting.

Abstract: A stator of an electric motor comprises a laminated iron-core (1) having dovetail grooves, end plates (2) and steel bars (3) which are accommodated in the dovetail grooves and have a trapezoidal shape in cross-section. The steel bars (3) are arc-welded to the laminated iron-core (1) and to the end plates (2).

Abstract: An intake system of an engine comprising a main intake passage which has a throttle valve therein. The throttle valve is controlled by a main actuator. An auxiliary intake passage is branched off from the main intake passage located upstream of the throttle valve and is connected to the main intake passage located downstream of the throttle valve. An auxiliary valve, controlled by a subactuator, is arranged in the auxiliary intake passage. The vehicle speed is controlled by the main actuator when the vehicle speed is too increased or too reduced relative to a set speed to be maintained. Contrary to this, the vehicle speed is controlled by the subactuator when the vehicle speed is maintained at a speed near the set speed.

Abstract: The ignition timing of an internal combustion engine is controlled to a fixed value during starting or for a period just after starting. However, if the engine is in a high-speed operating condition, the above control for fixing the ignition timing is interrupted and the ignition timing is controlled to change depending upon the change of the operating conditions of the engine.

Abstract: The idle air flow is adjusted by a step motor depending upon a drive signal applied to the step motor, so as to control the idling rotational speed of the engine. When the engine is under a certain operating condition during cranking, in which condition the step motor cannot be normally actuated, the drive signal is inhibited from being applied to the step motor.

Abstract: The ignition timing of an internal combustion engine is set to a fixed value if a predetermined signal is applied to a predetermined input terminal for servicing the ignition timing. However, if the engine is not in the idling condition, the ignition timing is controlled, as usual, depending upon the operating condition of the engine, even when the predetermined signal is applied to the service input terminal.

Abstract: A spark advance angle is calculated depending upon the flow rate of air sucked into the engine or the pneumatic pressure in the intake manifold and upon the rotational speed of the engine. The calculated spark advance angle is corrected in response to the temperature of the air sucked into the engine.

Abstract: A rotation detector wherein a rotary disk formed with slits in the circumferential direction thereof at predetermined regular intervals and connected to a driving source is disposed between a light emitting element and a light receiving element, and the light sensed by the light receiving element is intermittenlly interrupted by rotation of the rotary disk, whereby rotation of the driving source is detected. One of the rotation detectors is of such an arrangement that a parallel circuit is constituted by a resistor and a series circuit including a feedback resistor and a switching element, and this parallel circuit connects a power source and a light emitting element. Additionally, another of the rotational detectors is of such an arrangement that a comparator, in which a reference level is set, is used to compare outputs from a light emitting element with the reference level.

Abstract: An electronic control device for an automobile is equipped with a circuit for producing a first reset pulse when power is initially supplied to the electronic control device, and a circuit for producing a second reset pulse when the engine is cranked by a starter motor. Thus, an electric digital computer in the electronic control device is initialized in response to not only the first reset pulse but also the second reset pulse.

Abstract: The amount of fuel supplied to the engine is corrected in accordance with an air-fuel ratio correction coefficient. When the engine is in a predetermined first operating condition, the correction coefficient is calculated depending upon the detected concentration of a predetermined component in the exhaust gas, and thus the above correction is performed by closed-loop control. When the engine is not in the first operating condition, the correction coefficient is fixed, and thus the above correction is performed by open-loop control. An average value of the calculated correction coefficient is calculated only when the engine is in a predetermined second operating condition. An initial value of the air-fuel ratio correction coefficient when closed-loop control is resumed is determined to be the calculated average value.

Abstract: An internal combustion engine provided with a system for controlling the predetermined idling rotational speed N.sub.F of the engine, and a system for operating a fuel injector so that the injector is de-energized when the rotational speed is higher than N.sub.cut and the injector is energized when the rotational speed is lower than N.sub.RTN. A value of N.sub.cut is the product of N.sub.F and a predetermined positive value .alpha..sub.1 and the value of N.sub.RTN is the product of N.sub.F and a predetermined positive value .alpha..sub.2 (<.alpha..sub.1).

Abstract: A feedback operation check signal which indicates whether or not the feedback amount determined depending the output signal from the exhaust gas sensor to control the air-fuel ratio is within a predetermined range is fed to an information output terminal, when the throttle valve is in the idling position. On the other hand, when the throttle valve is not in the idling position, an electrical signal which is synchronized with the output signal from the exhaust gas sensor is fed to the same information output terminal.

Abstract: Electric signals produced in association with both a speed of movement of an acceleration pedal and an engine temperature are transmitted to a fuel injection valve in an intake system asynchronously with the running of an engine, so that an amount of fuel being injected from the fuel injection valve is increased as the speed of movement of the acceleration pedal increases and as the engine temperature is lowered. As a result, fuel is injected at a proper rate according to both the acceleration required and the engine temperature, the driving feeling during acceleration as well as a fuel consumption rate are improved, and an amount of detrimental components in the exhaust gases is lowered.

Abstract: The flow rate of intake air sucked into an internal combustion engine when a throttle valve of the engine is at the idling position is controlled so that the actual rotational speed of the engine becomes equal to a desired rotational speed of the engine. This desired rotational speed of the engine is determined by a predetermined calculation, in accordances with the warming-up state of the engine.

Abstract: In a method of computing and controlling the fuel injection quantity of a fuel injection system and the ignition timing of an ignition system of an international combustion engine by a microcomputer in accordance with operating conditions of the engine, a discrimination signal indicative of the presence or absence of misfiring is generated in accordance with an electric signal from the ignition system so that when misfiring occurs, even if fuel injection quantity data has already been computed, data for reducing the fuel injection quantity to zero is generated in response to the discrimination signal to stop fuel injection.

Abstract: According to the present invention, an amount of fuel being supplied to an internal combustion engine during acceleration is controlled in association with a desired value of acceleration (a degree of acceleration) and a temperature of the engine. The amount of fuel being supplied increases, as the desired value of acceleration is increased, and as the engine temperature becomes lower. Thus, an engine output necessary for rapid acceleration is positively provided, with the assurance of a desirable driving feeling at slow acceleration.

Abstract: An average value of an air-fuel ratio correction signal, which is gradually increased or decreased in accordance with output of an exhaust gas sensor for detecting the concentration of a particular component in the exhaust gas, and which is utilized for controlling air-fuel ratio of the mixture supplied to an engine, is generated. Then, the generated average signal is compared with a plurality of predetermined values to discriminate a range in which the average signal is positioned among a plurality of ranges specified by the plurality of predetermined values. Thereafter a signal which represents the discriminated range is produced. This signal energizes an indicator to inform an operator of the basic air-fuel ratio condition of the engine.

Abstract: A method is disclosed for automatically shifting the sub-transmission of a vehicle which is also equipped with a manual transmission operated by hand by the driver. When the driver shifts by hand to a certain gearing ratio, a vehicle operating parameter is detected, and, on the basis of this detected value, the procedure for shifting the sub-transmission is modified. Shift control of the sub-transmission is performed in accordance with this modified sub-transmission shift procedure, for a first time period, while the manual transmission remains in this gearing ratio, and subsequently for a second time period shift control of the sub-transmission is performed so as to maximize fuel economy, while the manual transmission remains in this gearing ratio.