Mazda Motor Corporation

Tetsuro Takaba

Tetsushi Hosokai

Hideki Kobayashi

Toshihiro Ishihara

Kazuo Sasaki

Hidetoshi Nobumoto

Kunitomo Minamitani

Shingo Harada

Yuji Shitani

Yoshitaka Tabara

Tomotsugu Rikitake

Tetsuya Kyakuno

Terufumi Yamashita

Minoru Kuriyama

Toshihide Nishikawa

Hiroshi Ninomiya

Yuji Sato

Tetsuya Nishizato

Shieaki Kakizaki

Manabu Arima

Takashi Ueno

An automatic transmission control system causes a downshift to a gear which can provide an effect of engine braking greater than that provided before the downshift when the vehicle falls its speed with a specified rate of speed reduction as a result of footbrake application while the vehicle is traveling on a downgrade having a slope greater than a specified slope.

Control system for automatic transmission

An automatic transmission control system, which applies an ordinary gear shift control map set up for flat road driving and a downgrade gear shift set up for downgrade driving which has broadened range of driving conditions for lower gears, causes gear shifts according to the ordinary gear shift control map even during downward driving when an accelerator pedal is stepped on with intention of accelerating the vehicle.

Gear shift control system for automatic transmission

An alternator control system controls a field current passing an alternator so as to regulate a terminal voltage of a vehicle battery to a target voltage, based on a deviation of the terminal voltage from the target voltage, by feedback control. The field current is corrected based on a delay in current generation of the alternator.

Alternator control system

A hydraulic control system for a power train including a shift speed mechanism, a frictional element for switching a shift characteristic of the shift speed mechanism, a hydraulic control mechanism for controlling a hydraulic pressure, a target shift time setting device for setting a target shift time based on an input speed difference of the shift speed mechanism through the shift operation and an input torque introduced to the shift speed mechanism, an angular acceleration calculator for calculating an angular acceleration of an input member of the shift speed mechanism based on the target shift time obtained through the target shift time setting device and the input speed change of the shift speed mechanism through the shift operation, an inertia hydraulic pressure setting device for setting an inertia hydraulic pressure for coping with a moment force due to a moment of inertia of a power transmitting system to the shift speed mechanism based on the angular acceleration of the input member of the shift speed mechanism obtained through the angular acceleration calculator, an input torque pressure setting device for setting an input torque hydraulic pressure corresponding to the input torque introduced to the shift speed mechanism based on the input torque and, a target pressure setting device for setting a final target hydraulic pressure for the hydraulic control mechanism based on the inertia hydraulic pressure and the input torque hydraulic pressure. The shift shock is effectively suppressed.

Hydraulic control system of automatic transmission

An ignition timing control system for an engine equipped with an automatic transmission corrects an ignition timing advance so as to retard ignition upon a demand to drop engine output torque when resumption of fuel injection is required after it has been interrupted during deceleration or when a shift of the automatic transmission is required. The ignition timing advance is corrected by a decaying retardation value so as to gradually fall with the passage of time. The corrected ignition timing advance is kept above a specific lower ignition timing advance limit, which is set smaller for lower air charging levels than for higher air charging levels. The corrected ignition timing advance is also kept below a specific lower limit ignition timing advance, which is set larger for lower air charging levels than for higher air charging levels.

Ignition timing control system for engine

A fuel control system for an engine has a fuel injector which injects fuel into an intake passage communicating with a combustion chamber. The quantity of a direct delivery part of fuel injected from the fuel injector which is directly fed to the combustion chamber is estimated, the quantity of a drawn part of fuel which has been on a wall surface of the intake passage and is vaporized and fed to the combustion chamber together with the direct delivery part is estimated, and the quantity of fuel to be injected from the fuel injection means is dcetermined on the basis of the estimated quantities of the direct delivery part and the drawn part so that the sum of them provides a desired quantity of fuel to be fed to the combustion chamber. The estimated quantity of at least one of the direct delivery part and the drawn part is increased as a factor which governs the degree of evaporation of the fuel on the wall surface changes in such a direction as to promote evaporation of the fuel on the wall surface.

Fuel control system for internal combustion engine

An air-fuel ratio control system for an engine has an air-fuel ratio sensor which generates an output value which changes according to an air-fuel ratio in an air-fuel mixture fed to the engine. An upper preset value which corresponds to an output value of the air-fuel ratio sensor for an air-fuel ratio which is larger than a stoichiometric air-fuel ratio and a lower preset value which corresponds to an output value of the air-fuel ratio sensor for an air-fuel ratio which is smaller than the stoichiometric air-fuel ratio are set. They are respectively reduced and increased by a predetermined value at one time at regular intervals, and are shifted each time the output value of the air-fuel ratio sensor exceeds the upper preset value at that time and reduces below the lower preset value at that time, to the output value of the air-fuel ratio sensor at that time. It is determined that the air-fuel ratio sensor is abnormal when the difference between the upper and lower preset values becomes smaller than a predetermined reference difference.

Air-fuel ratio control system for engine

In a fuel control system for an internal combustion engine, fuel is injected in a quantity the direct delivery part of which provides a desired quantity of fuel to be actually fed to the engine together with the drawn part of the intake-manifold wetting fuel. The quantity of the intake-manifold wetting fuel on the basis of which the quantity of the drawn part is calculated is calculated on the basis of the quantity of the adhering part of the fuel which was injected by the preceding injection and the quantity of the residual part of the preceding intake-manifold wetting fuel.

An idle speed control system for an engine includes an idle regulator valve which controls the amount of intake air to be fed to the engine when the engine idles and a control unit which detects an engine speed and controls the opening of the idle regulator valve so that the detected engine speed converges on a target idle speed. The control unit calculates a basic air charging efficienty required to fixedly operate the engine at a target idle speed, calculates a first target air charging efficiency by feedback correction of the basic air charging efficiency on the basis of a correction value which is determined according to the difference between an actual idle speed and a target idle speed, calculates a second target air charging efficiency which is the air charging efficiency obtained when the engine is fixedly operated at a detected idle speed while the amount of intake air is kept at a mass flow which will fixedly provide the first target air charging efficiency, calculates a final target mass flow which provides a first-order lag air charging efficiency equal to the second target air charging efficiency, and controls the opening of the idle regulator valve on the basis of the final target mass flow.

Idle speed control system for engine

An airflow meter detects an amount of intake air flowing through an intake passage of the engine, and a fuel injector injects fuel in an amount which is determined according to the amount of intake air detected by the airflow meter. A controller calculates moving averages of outputs of the airflow meter, and the ratio of the difference between each output of the airflow meter and the moving average to a value derived from the moving average. The controller causes the fuel injector to increase the amount of fuel to be fed to the engine when the ratio is not smaller than a predetermined reference threshold value.

Fuel control system for engine

A multi-cylinder internal combustion engine is provided with a fuel injection system, which includes a plurality of fuel injection nozzles securely mounted in independent intake passages communicating with combustion chambers of respective cylinders, an air-flow sensor for detecting the amount of intake air to be led into each combustion chamber, a crank angle sensor and a cylinder discrimination sensor for detecting the present stroke timing of each cylinder, a speed sensor for detecting the engine speed and a control unit for outputting a signal to the fuel injection nozzles so that a predetermined amount of fuel may be injected to each cylinder at a predetermined timing on the basis of values detected by the respective sensors. The control unit calculates the injection timing of fuel to be injected into each cylinder so that the injection start timing may be altered in compliance with driving conditions of the engine. The control unit also calculates the amount of fuel to be injected into each cylinder on the basis of at least the amount of intake air and the engine speed. The amount of intake air is detected at a timing which is altered in compliance with the injection start timing and close to this timing.

Fuel injection system for an internal combustion engine

Oscillation of the engine is detected by an oscillation sensor which outputs a signal representing the oscillation of the engine. The maximum value of the output of the oscillation sensor during combustion period in each cycle is detected. The maximum values obtained in a predetermined number of cycles are stored in a memory and knock occurrence is determined on the basis of the predetermined number of maximum values output from the memory.

Engine knock control system

An ignition timing correcting circuit which retards ignition timing when knock occurs and advances ignition timing when knock does not occur. An optimal ignition timing on which the ignition timing is to be converged is set to a latest ignition timing to which the ignition time can be retarded without raising the exhaust gas temperature higher than a predetermined value at the actual air-fuel ratio at that time. The actual ignition timing corrected by the ignition timing correcting circuit is compared with the optimal ignition timing. An air-fuel ratio control circuit corrects the air-fuel ratio toward the lean side when the actual ignition timing is on the advance side of the optimal ignition timing and toward the rich side when the former is on the retard side of the latter.

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Hiroshima, Japan

Tetsuro Takaba