Mazda Motor Corporation

Hideki Kobayashi

Tetsushi Hosokai

Tetsuro Takaba

Toshihiro Ishihara

Masaki Fujii

Hideki Kusunoki

Hiroyuki Matsumoto

Ryo Shimizu

Shigetoshi Kawano

An idle speed control valve in a path bypassing an engine throttle valve is regulated in opening by feedback control and learning control in which a learned value depends upon a feedback control value to cause the engine to idle at a target speed of rotation. The determination of learned value is interrupted while a purge valve is remained open to purge fuel vapors into an air intake system for a specified period of time after detection of engine idling and resumed at a lapse of the specified period of time with interruption of on-idle fuel vapor purge. After the determination of learned value, the on-idle fuel vapor purge is resumed until an automatic transmission is shifted to, for instance, a drive range.

Control system for automobile engine

A fuel control system for feedback controlling a purge gas flow rate as well as an air-to-fuel ratio which learns the concentration of fuel of a purge gas based on an average of air-to-fuel ratio control values at adjacent reversal there of between an upward tendency and a downward tendency and determines the content of fuel of the purge gas based on the purge gas concentration by which the amount of fuel delivered by an injector is reduced.

Fuel control system for automobile engine

A supercharging pressure control device for an engine having a supercharger, which is driven by the engine and disposed in an intake passage downstream of an engine throttle valve, includes a bypass passage. The bypass passage connects a part of the intake passage, upstream from the supercharger and downstream from the engine throttle valve, and a part of the intake passage downstream from the supercharger. A bypass valve is disposed in the bypass passage. The bypass valve is controlled so as to allow intake air to bypass the supercharger at a controlled flow rate.

Supercharged pressure control device for supercharged engine

A fuel control system causes a fuel injector to interrupt fuel injection during a continuous decrease in engine speed to a lower limit of a hysteresis range for fuel supply/fuel interruption and to resume the interruption of fuel supply after a continuous increase in engine speed beyond an upper limit of the hysteresis range and further causes a compulsory interruption of fuel supply when a transition of the engine from non-deceleration to deceleration while the engine operates at speeds between the lower and upper limits of the hysteresis range.

Fuel control system for engine

For an internal combustion engine with a supercharger, a slip of the driven wheel is controlled by reducing torque of the engine, when the extent of the slip becomes large in relation to a road surface. When the running status of the engine exists in a non-supercharging region, the slip is controlled by at least one of operations for reducing the amount of fuel to be supplied to the engine and for retarding the timing of ignition (first slip control). On the other hand, in a supercharging region, the slip is controlled by lowering the pressure to be supercharged (second slip control). In a transient period of time when the running status of the engine is caused to shift from the non-supercharging region to the supercharging region when the first slip control is being conducted in the non-supercharging region, the first slip control is allowed to be continued until the slip is caused to be converged, in place of the second slip control.

Engine control system

In a fuel control system of an engine having an air conditioner driven by the engine, fuel supply is cut during deceleration of the engine when the engine speed is higher than a first preset value with the air conditioner on and when the engine speed is higher than a second preset value with the air conditioner off, the first preset value being higher than the second preset value. When the air conditioner is turned off during the deceleration of the engine, fuel supply is cut when the engine speed is higher than the first preset value, and when the air conditioner is turned on during the deceleration of the engine, fuel supply is cut when the engine speed is higher than the second preset value.

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

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.

Growing community of inventors

Hiroshima, Japan

Hideki Kobayashi