Honda Giken Kogyo Kabushiki Kaisha

Honda Motor Co., Ltd.

Honda Giken Kogyo K.k.

Matsushita Electric Industrial Co., Ltd.

Oki Electric Industry Co., Ltd.

Akihiro Yamato

Yutaka Otobe

Shumpei Hasegawa

Shigeo Umesaki

Makoto Hashiguchi

Akihiko Koike

Takafumi Nishikawa

Noriyuki Kishi

Takeo Kiuchi

Kazuo Otsuka

Akira Fujimura

Yuzuru Koike

Masahiko Yakuwa

Hidenobu Nagase

Kikuo Tomozawa

Takehiko Hosokawa

Kiyoshi Miyaki

Fumio Yatabe

Kyozo Futa

Hayato Yasui

Nobutoshi Maruyama

A method of detecting abnormality in an exhaust gas concentration sensor in an internal combustion engine equipped with a fuel supply control system which controls a quantity of fuel to be supplied to the engine in a feedback manner responsive to a value of an air-fuel ratio correction value set in response to an output signal from the sensor. The sensor output signal is monitored from the time a first predetermined period of time has elongated from the start of the engine. The sensor is diagnosed as abnormal if the output signal has continually maintained a substantially constant value over a second predetermined time period elapsed following the first predetermined time period. The first predetermined time period corresponds to a time lag in rise of the output signal. The second predetermined time period is set such that the sum of the first and second preetermined time periods is shorter than a period of time within which the sensor becomes completely activated after the start of the engine.

Abnormality detecting method for exhaust gas concentration sensor for

A method of controlling the quantity of intake air being supplied to an internal combustion engine equipped with means for increasing the intake air quantity by a required amount in response to operating conditions of the engine. The intake air quantity increasing means is actuated for a limited period of time to increase the quantity of intake air when it is determined that a predetermined condition is satisfied for terminating interruption of the fuel supply to the engine, which is carried out at deceleration of the engine. Preferably, the intake air quantity increasing means is actuated when the rate of decrease in the rotational speed of the engine is larger than a predetermined value, while the predetermined condition is determined to be satisfied.

Intake air quality control method for internal combustion engines at

A method of controlling the fuel supply to an internal combustion engine at acceleration, wherein a quantity of fuel to be supplied to said engine is increased by the use of a accelerating fuel increment set in response to at least the valve opening speed of a throttle valve arranged in an intake passage of the engine. The accelerating fuel increment is set in response to a parameter value representative of engine load as well as to the valve opening speed of the throttle valve, whereby the fuel quantity is increased by an amount optimal for the engine load, to improve accelerability and emission characteristics of the engine.

Method of controlling the fuel supply to internal combustion engines at

A method for controlling air-fuel ratio of the mixture to be supplied to the engine detects whether or not the amount of the fuel to be supplied to the engine is greater than a reference amount. A feedback control in which the air/fuel ratio is corrected according to an oxygen concentration in the exhaust gas is performed when the amount of the fuel to be supplied to the engine is equal to or smaller than the reference level, while an open loop control in which the air/fuel ratio of the mixture is determined irrespective of the oxygen concentration is performed if an operational state of the engine in which the amount of the fuel to be supplied to the engine is greater than the reference level has continued for more than a predetermined time period.

Method for controlling air/fuel ratio of fuel supply system for an

A method of controlling in a feedback manner the air-fuel ratio of an air-fuel mixture supplied to an internal combustion engine to desired values by correcting the fuel quantity supplied to the engine by means of a correction coefficient which varies in response to output from an exhaust gas ingredient concentration sensor arranged within an exhaust passage, when the engine is operating in an air-fuel ratio feedback control effecting region. When the engine is operating in a predetermined accelerating condition, a mean value of the correction coefficient is calculated and stored. When the engine subsequently enters the predetermined accelerating condition, the air-fuel ratio feedback control is effected using the stored mean value as an initial value of the correction coefficient.

Air-fuel ratio feedback control method for internal combustion engines

The present invention relates to a method of detecting the number of revolutions of an internal combustion engine. Utilizing the presence of a certain multiple relationship between the period of a top dead-center signal and the period of a cylinder discrimination signal, the present invention is constructed so that, with respect to clock signals to be counted for detecting the number of revolutions, between the period of a clock signal used when using the top dead-center signal and the period of a clock signal used when using the cylinder discrimination signal there exists a multiple relationship which is the same as the multiple relationship between the period of the top dead-center signal and that of the cylinder discrimination signal.

Method of detecting the number of revolutions of internal combustion

The fuel supply to an internal combustion engine is decreased when the engine is in an operating region wherein the intake passage pressure is lower than a first predetermined value. The first predetermined value is corrected in response to detected atmospheric pressure encompassing the engine. Further, the fuel supply to the engine is interrupted when the engine is in a second operating region wherein the intake passage pressure is lower than a second predetermined value, which is lower than the first predetermined value. The second predetermined value is corrected in response to the detected atmospheric pressure, together with the first predetermined value.

Method of controlling fuel supply to an internal combustion engine at

An amount of fuel to be supplied to an internal combustion engine is determined in dependence upon operating conditions of the engine and is corrected by a correction variable dependent upon atmospheric pressure. The correction variable is set so as to increase with a decrease in atmospheric pressure, and the set value of the correction variable is modified so as to decrease with a rise in the engine rotational speed. The correction variable resulting from this modification is added to the amount of fuel to be supplied to the engine to correct the same.

Method of correcting air-fuel ratio for atmospheric pressure in internal

A method of controlling the operating amount of a control valve for regulating the quantity of supplementary air being supplied to an internal combustion engine, in a feedback manner responsive to the difference between a desired idling speed and an actual engine speed, while the engine is in a predetermined idling region. When the engine is in a predetermined decelerating region immediately preceding the predetermined idling region, a basic value of the operating amount of the control valve is corrected in dependence upon a detected value of the engine temperature and a detected value of the decreasing rate of the engine speed. When the engine is further decelerated into the predetermined idling region, the feedback control is started by applying the corrected basic value of the operating amount of the control valve as an initial value thereof. Preferably, when the engine is in the predetermined decelerating region, the operating amount of the control valve is set to a value equal to the initial value applicable at the start of the feedback control, and supplementary air is supplied to the engine in a quantity corresponding to the set operating amount of the control valve.

Idling speed feedback control method for internal combustion engines

There is a method for controlling the fuel supply of an internal combustion engine having a throttle valve in the intake air system. It is detected that an angular position of a crankshaft of the engine coincides with a predetermined crankshaft angular position. Whenever this coincidence is detected, the pressure in the intake air passage downstream of the throttle valve and the engine rotating speed or the value of the inverse number thereof is detected on the basis of the interval between the detections of the crankshaft angular position. The reference basic fuel supply amount which is to be supplied to the engine is determined in accordance with the present detection value P.sub.BAn of the pressure in the intake air passage. The present reference value M.sub.eAVEn having a predetermined functional relationship to the present detection value M.sub.en and previous reference value M.sub.eAVE(n-1) of the engine speed or of the value in inverse proportion thereof is set. The correction fuel supply amount is decided on the basis of the present reference value M.sub.eAVEn and is added to the basic fuel supply amount. Then the injection amount of fuel commensurate with the result of this addition is supplied to the engine. Thus, the driveability of the engine is improved.

Method for controlling the fuel supply of an internal combustion engine

A method for controlling the fuel supply of an internal combustion engine having a throttle valve in the intake air system is provided. It is detected that the crankshaft of the engine is at a predetermined crankshaft angular position. At every detection of this crankshaft position, the pressure in the intake air passage downstream of the throttle valve is detected. The present reference value P.sub.BAVEn having predetermined functional relations regarding the present detection value P.sub.BAn of the pressure in the intake air passage and the preceding reference value P.sub.BAVE(n-1) is set. The amount of the fuel supply into the engine is determined on the basis of this present reference value P.sub.BAVEn. The presumptive value of the intake air absolute pressure is calculated in consideration of the correction values with respect to the time lag in control operation and to the fuel deposition on the wall surface in the intake air manifold. Therefore, the proper reference fuel supply amount into the engine can be accurately determined, so that a driveability is improved.

A method of controlling the air-fuel ratio of an air-fuel mixture being supplied to an internal combustion engine includes comparing the value of a signal indicative of the concentration of an exhaust gas ingredient with a predetermined reference value, detecting from the comparison result a first change in the air-fuel ratio of the mixture supplied to the engine from a value richer than a predetermined value to a value leaner than same, or a second change in the air-fuel ratio of the mixture from a value leaner than the predetermined value to a value richer than same, correcting the value of an air-fuel ratio control signal by increasing or decreasing same by a first predetermined correction value in response to the first change or the second change thus detected, and controlling the air-fuel ratio of the mixture in a feedback manner responsive to the value of the air-fuel ratio control signal thus corrected. A second predetermined correction value, in lieu of the first predetermined correction value, is applied to correction of the air-fuel ratio control signal in response to a selected one of the first change and the second change with a cycle a predetermined number of times as large as the fluctuation cycle of the exhaust gas ingredient concentration-indicative signal.

A fuel supply control method of controlling the quantity of fuel being supplied to an internal combustion engine after cranking thereof. Upon generation of a predetermined control signal immediately after the cranking of the engine, an initial value of a fuel increment is set, which corresponds to the engine temperature. Subsequently, the set initial value is decreased at a predetermined rate upon each generation of the predetermined control signal. A quantity of fuel is set by the use of the thus decreased value of the fuel increment and supplied to the engine in synchronism with generation of the predetermined control signal. When the fuel increment has a value larger than a predetermined reference value, the value of the fuel increment is decreased at a first rate, while when it has a value smaller than the predetermined reference value, it is decreased at a second rate smaller than the first rate. Preferably, the predetermined reference value assumes a value dependent upon the initial value of the fuel increment, e.g. a product obtained by multiplying the initial value of the fuel increment by a predetermined coefficient. Further preferably, when the fuel increment value is smaller than a fixed value, it is decreased at the second rate, even if it is larger than the predetermined reference value.

Fuel supply control method for internal combustion engines immediately

A method for detecting an abnormality in the functioning of an electronic control system of the type including at least one input means, and at least one output means, wherein the input means is operable to detect the value of a parameter determining the operation of the output means and generate a signal indicative of the detected parameter value, on the basis of which the operation of the output means is controlled. First, a determination is made as to whether or not a predetermined condition exists wherein determination of the above abnormality can be effected. When the predetermined abnormality detection-permitting condition exists, it is determined whether or not the above detected parameter signal value from the input means or an operating amount signal indicative of the operation of the output means has a value satisfying a predetermined condition of normal operation. When the detected parameter signal value is determined not to show a value satisfying the above predetermined condition of normal operation, the time elapsing from the determination of dissatisfaction of the same condition is counted. When satisfaction of the predetermined condition of normal operation is determined before the counted elapsed time value reaches a predetermined value, the counting is interrupted. When the counted elapsing time value reaches the predetermined value, it is diagnosed that an abnormality exists in the functioning of the above corresponding input means or output means. When a predetermined abnormality detection-prohibiting condition exists after the counting of the elapsed time has been started and before the counted elapsed time value reaches the above predetermined value, the counting is also interrupted. The present abnormality detecting method can advantageously be applied to an electronic control system for internal combustion engines.

Method for detecting abnormality in the functioning of an electronic

A fuel supply control method for an internal combustion engine having exhaust gas purifying means arranged in its exhaust passage, in which a plurality of predetermined basic fuel quantity values corresponding, respectively, to different predetermined values of at least one operating parameter of the engine are selectively read out in response to detected values of the same parameter to thereby determine fuel supply quantities appropriate to operating conditions of the engine. Among the above basic fuel quantity values, those which correspond to ones of the above predetermined parameter values that are to be assumed when the engine is operating in an idling region are set at such predetermined values as to obtain an air-fuel mixture having a predetermined air-fuel ratio at which the exhaust gas purifying means can exhibit the maximum conversion efficiency. When the engine is operating in the idling region, each of the above corresponding basic fuel quantity values which is read out is decreased by a predetermined correction amount.

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Shiki, Japan

Akihiro Yamato