Abstract: A method and apparatus for detecting when the internal resistance of an oxygen sensor is too high for useful signal processing. A reference voltage is applied to the sensor signal to generate a test voltage which is compared with two different threshold voltages. The three possible magnitude states of the test voltage with respect to the thresholds cause the comparator output signals to define logical conditions which are processed by logical gating circuitry to inhibit a timing circuit which otherwise would switch fuel mixture preparation from sensor-controlled operation to open-loop, direct control after a period of time.

Abstract: An anti-stall device for an internal combustion engine provided with a fuel injection pump having a fuel control rack and a governor mechanism connected to the fuel control rack and which has a speed control lever, comprising:a circuit for generating a dc voltage in proportion to the rotational speed of the engine;a circuit for comparing and amplifying an output voltage of the dc voltage generating circuit and a reference voltage corresponding to the idling speed of the engine;a timer circuit for receiving outputs of the comparing and amplifying circuit as inputs to generate outputs for a predetermined period of time; andan electromagnetic actuator for utilizing the outputs of the timer circuit to drive said fuel control rack in a fuel quantity increasing direction.

Abstract: The disclosure describes an improvement to facilitate the start of an internal combustion engine, more particularly during wet weather and at low temperatures. The improvement comprises heating means associated with the spark plugs and/or with the engine distributor, a switch or a timer and lead connecting the heating means through the switch or timer, to the vehicle battery.

Abstract: In a non contact ignition circuit for an internal combustion engine, a current induced in the primary winding or an ignition coil is controlled and cut-off by operation, on and off, of a thyristor so as to produce a discharge in a spark plug. A capacitor connected to the gate of the thyristor is charged with an inverse voltage. When the rotational speed of the internal combustion engine exceeds a predetermined level, i.e. a state of overrotation, the inverse voltage stored in the capacitor is discharged whereby the gate potential of the thyristor is negatively biased relative to the cathode. Accordingly, during the discharging period of the capacitor, the triggering time of the thyristor and sparking are retarded as compared to the normal running condition of the internal combustion engine. Thereby overrotation of the internal combustion engine is prevented.

Abstract: A fuel cut-off apparatus is used with an electronically-controlled fuel injection system of the type in which metering of fuel in accordance with the operating conditions of an engine is controlled by the pulse time width of an injection pulse signal applied to electromagnetic fuel injectors. The fuel cut-off apparatus includes a delay circuit, whereby when a fuel cut-off condition is attained during deceleration periods of the engine, the fuel supply to the engine is cut-off after a predetermined time delay.

Abstract: A closed-loop emission control apparatus for internal combustion engines includes an exhaust composition sensor disposed at the upstream side of a catalytic converter which converts the noxious exhaust components into harmless products at the highest efficiency when the air-fuel ratio is controlled at a value in the vicinity of stoichiometry in accordance with a control signal derived from the sensed concentration of the exhaust composition. The output from the exhaust composition sensor is utilized to generate an offset voltage by averaging the instantaneous values of the sensed concentration, the offset voltage being combined with the control signal to cancel an error introduced thereinto during use of the apparatus.

Abstract: To eliminate the effects of disturbances, noise and interference in the signal derived from a speed-dependent signal generator coupled to the engine on the threshold response level of a threshold switch which, upon sensing a leading flank of the signal, causes a controlled transistor switch to turn ON to pass current through an ignition coil and, upon sensing the trailing flank of the signal, turns the switch OFF to induce an ignition pulse, a supervisory circuit is connected to the threshold switch which provides a bias voltage thereto so that the threshold switch will accurately and reliably respond to the trailing flank of the signal from the signal generator even in the presence of noise and interference voltages at a predetermined angular position of the crankshaft of the engine--absent a shift in the relative angular position of the signal from the signal generator and the crankshaft of the engine--to prevent failure of generation of an ignition pulse, or untimely, uncontrolled generation thereof.

Abstract: An air-to-fuel ratio control mechanism in an internal combustion engine operates in partial response to the output of a control circuit, which circuit in turn is responsive to the output of an oxygen sensor mounted in the exhaust of the engine. The control circuit biases the control mechanism toward a predetermined desired air-to-fuel ratio, normally at or near stoichiometric. When the sensor output deviates above a first predetermined value or below a second predetermined value for longer than a predetermined time period, a comparator circuit provides a disabling signal which disconnects the control circuit from the air-to-fuel ratio control mechanism. At the same time, the disabling signal connects a predetermined signal to the air-to-fuel ratio control mechanism. This predetermined signal simulates a nominal control circuit output to maintain the air-to-fuel ratio close to stoichiometric or some other preferred setting such as a air/fuel ratio which is lean.

Abstract: An ignition plug for an internal combustion engine which comprises a hollow cylindrical main body having one externally threaded end portion and the other end portion in the form of a nut, said threaded end portion being provided with jet orifices, air guide grooves and a communication groove; a tubular anode member having an insulation body and extending through said main body; a center electrode extending through said insulation body; and a check valve assembly mounted about the intermediate portion between the two end portions of the main body, said valve assembly comprising a ring-shaped valve housing having a tapered seat face and air intake bores and a ring-shaped valve body reciprocally received in said valve housing and having a matingly tapered outer surface for opening and closing said air intake bores in the valve housing.

Abstract: In a method and apparatus for controlling a combustion engine, a digital computer is adapted to calculate first and second values corresponding to optimal settings of fuel injectors and spark plugs in a time sequence by detecting changes of the amount of air flowing into the engine and the rotation speed of the engine. The computer is programmed to calculate the first and second values from first and second functions describing desired relationships among each setting of the fuel injectors and the spark plugs, the amount of air flowing into the engine and the rotation speed of the engine.

Abstract: In a fuel injected vehicle engine having pulse generating apparatus for controlling the activation of a fuel injector for the duration of fuel injection pulses according to the fuel requirements of the engine, apparatus responsive to the normal duration of the pulses is effective, when the normal pulses are shorter than a predetermined minimum desired pulse duration, to increase simultaneously both the intervals between the pulses and the durations of the pulses by a common factor N from the normal interval and durations, to increase fuel flow accuracy at low fuel supply rates.

Abstract: To prevent damage to the heating wire of an electrically heated glow plug due to non-uniform expansion of materials within the glow plug upon heating thereof, and particularly due to excessive expansion of filler material surrounding a spiraled heating wire, the filler material is made in two sections, one being located within the spiral of the heater wire and comprising a material of a thermal conductivity of expansion approximately matching that of the heater wire, typically high-temperature annealed aluminum oxide, magnesium aluminum spinel, silicon nitride, boron nitride, silicon carbide, or the like, the outer section between the heater wire and the inner wall of the glow tube being of a material of good heat conductivity, such as magnesium oxide.

Abstract: A sensor is located in the intake passageway of an engine for sensing a parameter representing a function of the air-fuel ratio of an air-fuel mixture produced for the engine and is heated to a predetermined temperature when the temperature of the sensor is below the predetermined temperature above which it is possible for the sensor to sense the parameter.

Abstract: A method for controlling the distribution of spark voltages generated by an ignition coil to spark plugs provided on multiple cylinders of a combustion engine. A spark voltage distributor is provided with a rotatable electrode connected to the ignition coil and multiple stationary electrodes connected to the respective spark plugs. The rotatable electrode is rotated by an electric motor at a speed depending upon the rotation speed of an engine output shaft and the rotational position of the output shaft indicative of the timing of spark voltage generation so that the engagement of the rotatable electrode with the stationary electrodes is synchronized with the spark voltage generation.

Abstract: A fuel supply system for an internal combustion engine wherein liquid fuel, as from an automobile gas tank, is supplied to a vapor chamber to maintain a predetermined liquid fuel level in the base of said chamber and in such chamber is transformed into vapor and eventually fed to the engine's intake manifold. Ambient air is admitted to the vapor chamber by an adjustable inlet valve and as the air is drawn through the chamber on its way to the engine it entrains the fuel vapors in the desired fuel-air mixture. The vaporizing of the liquid is increased by an absorbent splash assembly so supported in the vapor chamber that at least a part of such assembly normally engages the liquid fuel.

Abstract: A device for controlling the vacuum advancing of ignition timing including a vacuum advancer, a diaphragm valve, a first vacuum port opened to an intake passage which is positioned so as to be immediately upstream of a throttle valve when it is fully closed and downstream of the throttle valve when it is slightly opened. A second vacuum port is located absolutely downstream of the throttle valve, wherein the diaphragm valve produces a fraction of the intake manifold vacuum when the throttle valve is fully closed while it communicates therethrough the intake manifold vacuum supplied from the second vacuum port when the throttle valve is opened so as to position the first vacuum port at the downstream thereof.

Abstract: To detect substantial deviation of operation of the engine with fuel-air mixtures from stoichiometric relationships, particularly extended operation under very lean or enriched supply mixtures, the exhaust gases are conducted past a first sensor which provides a clearly defined voltage jump upon change of the exhaust gases between reducing and oxidizing state; and, additionally, to a second exhaust gas sensor and preferably to a third sensor, the second and third sensors being, respectively, responsive to the oxygen level in the exhaust gases and to the CO (or hydrocarbon) level in the exhaust gases, respectively, and additionally modifying the relative proportion of fuel and air of the mixture being fed to the engine.

Abstract: An air flow amount adjusting system produces an air-fuel mixture of a desirable air-fuel ratio by controlling the direction of movement of a bypass valve mounted in an additional air supply pipe adapted to supply additional air into either the intake system or exhaust system of an internal combustion engine in accordance with an output signal produced from a gas sensor mounted in the exhaust system of the engine and indicative of the air-fuel ratio of the mixture supplied to the engine. A two-level mode signal whose threshold corresponds to the desired air-fuel ratio is produced in accordance with the output signal of the gas detector. After the two-level mode signal has changed from one level to the other level, the movement of the bypass valve is stopped for a certain period of time. If desired, the stopping period of the bypass valve may be changed in accordance with the temperature of the engine.

Abstract: A carburetor has a float chamber and a device for adjusting the gaseous pressure in the float chamber. The device comprises a pressure source and a probe contacting the exhaust gas and delivering a signal which is a function of the exhaust gas composition. The device has an airflow pipe connecting the source to atmosphere, a throttle for impressing a head loss to the flow and controlled by the probe and a venturi located in the pipe and connected to the float chamber for giving a pressure which may be out of the range between the source pressure and atmospheric pressure.

Abstract: Disclosed is an internal combustion engine having a charcoal canister. The float chamber of the carburetor is connected to the canister via an evaporated fuel vapor passage. The carburetor has therein a slow fuel passage connected to the slow port which opens into the intake passage of the engine. The slow fuel passage is opened and, at the same time, the evaporated fuel vapor passage is closed by means of a single electromagnetic valve when the ignition switch is turned to the ON condition.