Abstract: An ignition device for a multi-cylinder internal combustion engine having an ignition coil, also positive and negative high voltages being alternately generated across the secondary winding of the ignition coil, and a distributor, the distributor comprising a center electrode, two electrical distributing conductors in the rotor of the distributor, the center electrode being connected electrically with the two electrical distributing conductors, the electrical distributing conductors including at least one center conductor and two projecting conductors for distributing electric power to side electrode, two diodes having opposite polarities being connected between the center conductor and the projecting conductors for electrical distribution, respectively, and a plurality of side electrodes adapted to be electrically coupled successively with the projecting conductors according to the rotation of the rotor, whereby positive and negative high voltages are supplied alternately to the side electrodes through the c

Abstract: Two closed circuits respectively are each comprised of a primary coil of a transformer for plug ignition, a transistor, a diode, a resistor and a common power source. When one of the transistors is conductive during the ignition period, the current in the related closed circuit increases. When the increased current appearing across the associated resistor exceeds a reference value, the associated comparator renders the conducting transistor nonconductive while it renders the other nonconductive transistor conductive, whereby the transistors continues a push-pull operation at given periods. Each diode is inserted either between the associated primary coil and the associated transistor or between the associated primary coil and the common power source.

Abstract: A method for detecting knock for an internal combustion engine having a plurality of cylinders in which a vibration sensor is attached to each cylinder and a peak value of vibration detected by the sensor is sampled over a predetermined interval near the top dead center. The sampled value is converted from analog to digital and stored for a predetermined number of sampling times to obtain the average value for each cylinder. Then the frequency of occurrences in which the ratio between the sampled peak value and the average value exceeds a reference value is obtained, and the knock is determined when the frequency of occurrences in any one cylinder exceeds a predetermined value or when the average frequency of occurrences of the all cylinders exceed another predetermined value.

Abstract: An ignition system for a spark-ignition engine includes an ignition coil for applying a high voltage to each spark plug, a switch device connected in series with the secondary of the ignition coil for preventing in response to its conduction the supply of the high voltage to the spark plug, and a control circuit for turning on the switch device at a predetermined time after the generation of the high voltage, whereby the discharging at the spark plug is prevented under the combustion condition.

Abstract: A linear solenoid valve actuation device comprises a step wave generating circuit comprising a converting circuit whereby the desired amount of control is computed at a predetermined period of clocks to hold or store the computed value until the next computation and generate a step wave voltage having a value corresponding to the computed value, and a current amplifier circuit for supplying to a linear solenoid valve a current having a value corresponding to the output voltage of the step wave generating circuit, thereby actuating the linear solenoid valve with a step waveform current.

Abstract: A rotary actuator for imparting a rotational force to a rotary valve member of a multi-way valve device has a cylindrical housing and an electric motor housed therein and being operative to produce a torque corresponding to the input current supplied to the motor. The motor shaft is hollow and rotatably journalled by the end walls of the motor housing. A torsion bar is housed in the shaft and fixed at one end to one end of the shaft. The other end of the torsion bar is fixed to the housing so that, when rotational force is imparted by the motor to the shaft and thus the rotary valve member connected thereto, the torsion bar produces a return force applied to the shaft. The angular position of the other end of the torsion bar about the axis thereof is adjustable within a limited range. The actuator is suited to impart a rotational motion of less than 180.degree. and provides a reduced hysteresis in the rotation characteristics.

Abstract: An apparatus for detecting knock for an internal combustion engine having a plurality of cylinders in which a vibration sensor is attached to each cylinder and a peak value of vibration detected by the sensor is sampled over a predetermined range near the top dead center. The sampled value is converted from analog to digital and stored for a predetermined number of sampling times to obtain the average value for each cylinder. Then the frequency of occurrences in which the ratio between the sampled peak value and the average value exceeds a reference value is obtained, and the knock is determined when the frequency of occurrences in any one cylinder exceeds a predetermined value or when the average frequency of occurrences of the all cylinders exceeds another predetermined value.

Abstract: A first temperature dependent resistor and a second temperature dependent resistor are disposed within a single gas passage defined by a branch pipe extending into a conduit for a gas whose flow rate is to be measured. An electric heater is located between these temperature dependent resistors and is heated for the purpose of measurement of the flow rate of the gas. A first reference resistor and a second reference resistor constitute a bridge circuit together with the first and second temperature dependent resistors, and the difference between the potentials at the terminals of the bridge circuit is amplified by a first differential amplifier circuit. The difference between the output voltage of the first differential amplifier circuit and a predetermined reference voltage is then amplified by a second differential amplifier circuit.

Abstract: Spark ignition plugs are used in place of the glow plugs in a Diesel engine. As long as engine preheating contacts remain closed, pulses of a fixed frequency are applied to two transistors arranged in a push-pull configuration and connected to the primary coil of a transformer so that an engine plug connected to the secondary coil of the transformer repeatedly discharges continuously.

Abstract: An electronically controlled ignition system for internal combustion engines. Reference position detecting means generates reference signals and angular position detecting means generates angular signals indicative of the angular positions of an engine at every predetermined angle of its rotation. Computing means responsive to engine operating condition parameters computers a proper ignition coil energization starting timing data and a proper ignition coil de-energizing timing data. An ignition coil control circuit comprising latch circuits, comparator circuits and counting means converts the ignition coil energization starting timing data and the ignition coil de-energization timing data into pulses having a corresponding pulse width with respect to the rotational angle of the engine to supply an ignition coil energization starting timing signal and an ignition coil de-energizing timing signal to said ignition coil.

Abstract: An exhaust gas recirculation system comprises a speed detector for generating an engine rotational speed signal and a reference rotational position detection signal, a pressure sensor for detecting the negative pressure in the intake pipe of an engine to generate a negative pressure signal, a microcomputer responsive to the negative pressure signal and the rotational speed signal generated at the reference rotational position of the engine to compute an amount of exhaust gas recirculation in synchronism with the reference rotational position detection signal, and an electronic control circuit for controlling the opening of an exhaust gas recirculation control valve in accordance with the computed amount.

Abstract: A flow measuring pipe includes therein an electric heater and a temperature dependent resistor positioned downstream of the electric heater. The lines of the electric heater are arranged in a direction to cross the lines of the temperature dependent resistor. If necessary, a flame arrester is further disposed downstream of the temperature dependent resistor.

Abstract: An apparatus for controlling an ignition coil of internal combustion engines including a power transistor connected to the primary winding of an ignition coil for controlling the energization and deenergization of the primary winding in response to a signal applied to the base of the power transistor. A feedback circuit, including a constant voltage diode, a capacitor and a resistor, is connected between the collector and base of the power transistor. When the power transistor becomes conductive from a nonconductive condition, a collector current of the power transistor flows through the capacitor and constant voltage diode due to the Miller integrator effect and the transition from nonconduction to conduction of the power transistor is made gradual thereby reducing a voltage generated in the secondary winding of the ignition coil.

Abstract: A gas flow measuring tube is provided in a duct through which gas to be measured is flown. In this gas flow measuring tube there are placed an electric heater and first and second temperature dependent resistors which are formed of resistance wires stretched across a plurality of respective insulator frames. A measuring circuit is provided for controlling electric power to be supplied to the electric heater in accordance with the resistance change of the temperature dependent resistors, and thereby measuring the amount of the flow of gas to be measured. The measured values are corrected in accordance with the temperature of the insulator frames.

Abstract: Voltages at the diagonal points of a bridge circuit are amplified in an AC differential manner and half-wave rectified, which bridge circuit is formed of reference resistors and temperature dependent resistors located in front and rear of an electric heater in a duct through which air to be measured flows. The half-wave rectified voltage is sampled and held in synchronism with a control pulse signal from an oscillation circuit so that the sampling and holding operation is performed substantially at the center of the period during which the half-wave rectified voltage is produced. The held voltage and a constant reference voltage are amplified in a DC differential manner and then applied to a power amplifier circuit which controls a supply voltage to the electric heater. The voltage to be applied to the bridge circuit is an intermittent voltage which is produced by a chopper circuit.

Abstract: A knocking detection method for internal combustion engines in which vibrations of the engine are detected by a vibration sensor and a peak value of the vibrations during a predetermined interval near the top dead center in each revolution of the engine is sampled. The peak value for each revolution is stored for a predetermined number of revolutions of the engine and an average value of the peak values is obtained. Then the ratio of each peak value to the average value is calculated, and the number of ratios whose magnitude exceeds a predetermined magnitude is expressed in terms of a rate or a percentage with respect to the total number of ratios, i.e., the predetermined number of revolutions of the engine. The presence or absence of the knocking is determined whether or not the rate or percentage is above a reference rate or percentage.

Abstract: The timing of spark ignition is set in normal operating conditions at a programed spark advance angle corresponding to the MBT (minimum spark advance for best torque). When knocking of the engine is detected by a vibration sensor, the ignition timing is delayed by a predetermined amount, e.g., 2.DELTA..theta., for each engine cycle that knocking is detected in synchronism with the rotation of the engine. When knocking is not detected, the ignition timing is advanced by another predetermined amount, for each engine cycle that knocking is not detected. e.g., .DELTA..theta.. In this method for controlling the spark timing, the amount of retardation, 2.DELTA..theta., is selected to be larger than the other amount of advance, .DELTA..theta..

Abstract: An engine ignition system includes a throttle sensor for detecting the position of a throttle valve. A control circuit is responsive to the detected throttle signal as well as the signals from other negative pressure and engine rpm sensors to generate a spark plug discharge start signal and a discharge stop signal. A high voltage generator supplies a high voltage to the respective spark plugs during the time interval between the time that the discharge start signal is generated and the time that the discharge stop signal is generated.

Abstract: In an exhaust gas recirculation system adapted to an internal combustion engine, the system comprises a servomotor to be operated by pneumatic pressure and a control valve actuated by the servomotor to control the quantity of exhaust gases recirculated into an intake manifold from an exhaust pipe. The pneumatic pressure applied to the servomotor is electrically controlled without undesired errors to satisfy the following function in relation to the engine intake manifold vacuum and the engine speed:Pe=f(Pv, N)where Pe is the pneumatic pressure applied to the servomotor, Pv and N respectively indicate the engine intake manifold vacuum and the engine speed.

Abstract: In a carburetor for an internal combustion engine, a control valve is disposed with an air passage through the carburetor structure to control the flow quantity of air to be mixed with fuel from a float chamber and a pneumatic servo-motor is operatively connected with the control valve to control the opening degree of the valve. The pneumatic pressure applied to the servo-motor is electrically controlled to satisfy the following function in relation to the engine intake manifold vacuum and the engine speed.Pd=f(Pv, N)where the character Pd is the pneumatic pressure applied to the servo-motor, and the characters Pv and N respectively indicate the engine intake manifold vacuum and the engine speed.