摘要:
A closed-loop emission control apparatus for internal combustion engines includes exhaust composition sensor for feedback control of the air-fuel mixture. When the temperature in the exhaust passage is lower than the operating temperature of the sensor, control is switched to an open-loop mode. The feedback control signal is fluctuated above and below a predetermined DC bias at periodic intervals during the open-loop mode to switch the control to the closed-loop mode in a minimum transition time as soon as the sensor's temperature condition warrants feedback control.
摘要:
A reference voltage, which is compared with an output voltage of an exhaust gas sensor in a differential signal generator of an electronic closed loop air-fuel ratio control system, changes depending upon a mean value of an output of the exhaust gas sensor provided in an exhaust pipe extending from an internal combustion engine. Furthermore, the magnitude of the reference voltage is limited in such a manner as to be within a predetermined range, or in other words, the magnitude of the reference voltage is limited at at least one of an upper and a lower values thereof.
摘要:
Emission control apparatus for internal combustion engines is provided with a sensor for detecting the concentration of a particular exhaust composition in the emissions from the engine. A signal indicating the deviation of the mixture ratio from a controlled point is generated by comparing the output from the sensor with a reference level, the signal being modified in amplitude according to a predetermined control characteristic and used to regulate the air-fuel mixture ratio at the desired control point. The varying magnitude of the sensed concentration is smoothed into a signal of slowly varying magnitude which is used to control the reference level so that error introduced into the deviation indicating signal due to the change with time in the output performance of the exhaust composition sensor is self-compensated. A level sensor is provided to detect when the reference level reaches an end of the control range to change the operating mode of the engine from closed-loop to open-loop mode.
摘要:
A circuit is provided in an electronic closed loop air-fuel ratio control system for starting and terminating the operation of the system at different voltages from an exhaust gas sensor.
摘要:
A method and system for correcting engine ignition timing without the use of any pressure sensor or vibration sensor and depending upon engine knocking is disclosed. The presence or absence of knocking is determined by reference to the rate of change of engine speed. This method is based on the fact that engine speed changes abruptly when engine knocking occurs, as compared with the normal engine condition, because of abrupt changes in pressure within the cylinders. The system of the present invention comprises an crankshaft angle sensor to generate a crankshaft angle pulse signal, a period measuring means to output an interrupt request signal and to determine the presence or absence of engine knocking, a microcomputer, and an ignition signal generator for outputting an ignition signal in accordance with an ignition timing signal and a dwell angle signal.
摘要:
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.
摘要:
A closed loop fuel control system for an internal combustion engine having in its exhaust system an exhaust composition sensor generating a signal indicative of air-fuel ratio in gases in the exhaust system and an integral controller providing integration on the generated signal for adjusting the ratio of air and fuel supplied to the engine, and a storage device which stores the output from the controller in response to a sensed particular engine operating parameter. The stored signal is later extracted in response to the sensing of the same engine operating parameter to rapidly vary the controller output.
摘要:
The spark advance control apparatus of the invention comprises a vacuum advance control mechanism and a speed advance control circuit. The vacuum advance control mechanism senses the vacuum pressure in the intake manifold of an internal combustion engine and generates an electrical pulse in advanced timing in relation to the sensed vacuum. The speed advance control circuit receives the pulse from the vacuum advance control mechanism, converts it into a voltage signal representative of the revolution of the engine crankshaft and generates an output voltage which varies nonlinearly as a function of the voltage signal. A pulse-width generator is provided having a first input connected to receive the pulse from the vacuum advance control mechanism and a second input connected to receive the nonlinear speed related voltage signal to generate a pulse which commences in response to the vacuum advance pulse and ends at a time determined by the speed related voltage signal. The trailing edge of the output from the pulse-width converter is utilized for ignition.
摘要:
A fuel control system for an internal combustion engine includes an exhaust gas sensor from which feedback control signal is derived, a limiter for limiting the maximum and minimum voltages of the control signal and a triangular wave generator. The triangular wave has a constant amplitude peak of which the maximum value is slightly greater than the maximum voltage of the control signal and the minimum value is slightly below the minimum voltage of the control signal. A comparator is provided to produce an output at one of two binary levels depending upon whether the control signal is above or below the instantaneous value of the triangular wave. The output from the comparator is a train of pulses whose duty cycle ranges from predetermined minimum to maximum values which correspond respectively to the minimum open and closure times of air-fuel mixing control valves.
摘要:
A fuel supply control system is disclosed which uses a stored program type digital computer for calculating a basic amount of fuel and modifying the basic amount in accordance with various correction factors dependent upon engine operating conditions so as to determine an actual amount of fuel supplied to an engine. The actual fuel amount is determined by adding all correction factors dependent upon engine temperature and multiplying the sum by the basic fuel amount.