Mazda Motor Corporation

Toshio Nishikawa

Mitsuo Hitomi

Makoto Hotate

Tadashi Kaneko

Nobuo Takeuchi

Tadataka Nakazumi

Hidefumi Fujimoto

Junsou Sasaki

Shunji Masuda

Takayuki Sumimoto

Itaru Okuno

Fumio Hinatase

Akinori Yamashita

Akihito Nagao

Misao Fujimoto

Junso Sasaki

Yoshitaka Tabara

Daisaku Moriki

Humio Hinatase

Kouichi Takahashi

Kazutoshi Othuka

Kobuo Takeuchi

Novuo Takeuti

A control system for an engine with an automatic transmission, including an output reducing system for reducing an output of the engine by a predetermined quantity in a speed change operation of the automatic transmission, so as to suppress a speed change shock generated in the speed change operation; and an output reduction control system for controlling a start timing of operation of the output reducing system so as to make a timing when output reduction of the engine is completed by the output reducing system coincide with a start timing of an actual gear shift operation of the automatic transmission. Accordingly, the engine output is reduced in the speed change operation of the automatic transmission, and the speed change shock generated in the speed change operation can be greatly suppressed by making the timing when the output reduction of the engine is completed coincide with the start timing of the actual gear shift operation of the automatic transmission.

Control system for engine with automatic transmission

A control system for an engine with a turbo supercharger includes a first switching device for switching an introduction of intake gas to the engine in accordance with engine speed between a first intake condition, in which a charging efficiency of the intake gas is improved in a lower engine speed condition, and a second intake condition, in which the charging efficiency of the intake gas is improved in a higher engine speed condition. The control system also includes a second switching device for switching a maximum supercharging pressure of the turbo supercharger from a lower pressure to a higher pressure in response to a switching operation between the first intake condition and the second intake condition. An improved charging efficiency of the intake gas can be obtained in a broader range of the engine speeds reducing the maximum supercharging pressure of the intake gas, thereby preventing knocking of the engine.

Control system for internal combustion engine with turbo supercharger

A mechanical supercharger is operatively connected to the engine output shaft when the engine speed is not lower than a predetermined engine speed and disconnected from the engine output shaft when the engine speed is lower than the predetermined engine speed. The engine load is detected and the predetermined engine speed is set lower as the engine load becomes lighter.

Control system for engine with mechanical supercharger

In an internal combustion engine with a supercharger, a timing or timings for varying characteristics of kinetic supercharging effects of intake air are synchronized with a timing or timings for varying supercharging pressures by the supercharger. Reduction in engine torque at the time when the supercharging pressure is shifted, can be compensated for by enhancement in the engine torque generated at the time when the characteristics of the kinetic effect are varied.

Intake system for an internal combustion engine with supercharger

A turbocharged engine is provided with a waste gate valve which limits the supercharging pressure in the intake passage downstream of the compressor of the turbocharger not to exceed a predetermined value. The intake passage has first and second pressure propagating paths downstream of the compressor. The pressure wave generated by the intake stroke of the combustion chamber is propagated substantially along the first pressure propagating path when the engine operates at a speed in a low engine speed range under heavy load and substantially along the second pressure propagating path when the engine operates at a speed in a high engine speed range. The part of the intake passage defining the first pressure propagating path is arranged so that a supercharging effect by a kinetic effect of intake air which becomes maximum at a predetermined engine speed in the low engine speed range can be obtained, and the part of the intake passage defining the second pressure propagating path is arranged so that a supercharging effect by a kinetic effect of intake air is better in the high engine speed range when the pressure wave is propagated along the second pressure propagating path than when the pressure wave is propagated along the first pressure propagating path. The predetermined engine speed is lower than an intercept engine speed for the second intake path.

Intake system for turbocharged engine

An engine is provided with a mechanical supercharger which is disposed in an intake passage of the engine and is driven by the output power of the engine. The supercharger is connected to and disconnected from the output power of the engine by a clutch. The engine has intake and exhaust valves which are opened and closed with an overlap time. A valve timing changing mechanism changes the overlap time in order to change the amount of air communicated between the intake and exhaust ports. A controller controls the valve timing changing mechanism and the clutch so that the amount of air communicated between the intake and exhaust ports is reduced and the supercharger is disconnected from the output power of the engine and does not operate when the operating condition of the engine is in a first operational range in which the amount of intake air is not more than a first preset value, the former is increased and the latter is connected with the output power of the engine so as to operate when the operating condition of the engine is in a second operational range in which the amount of intake air is not less than a second preset value which is larger than the first preset value, and the former is increased and the latter is disconnected from the output power of the engine when the operating condition of the engine is in a third operational range in which the amount of intake air is between the first and second preset values.

Supercharged engine

An intake system utilizing an air-fuel control which is changed in accordance with the coolant temperature. When the coolant temperature is lower than the first coolant temperature, an open loop control is carried out in accordance with the coolant temperature so that a fluctuation of the air-fuel ratio can be restricted so as to obtain a stability. An air-fuel feedback control is carried out between the first and second coolant temperatures wherein the air-fuel ratio is maintained at the stoichiometric value so that an increase of NO.sub.X emitted from the engine can be suppressed. In the region in which the coolant temperature exceeds the second temperature, an air-fuel feedback control is carried out in the lean mixture side of the stoichiometric value in accordance with the coolant temperature to thereby improve the emission performance of the engine.

Intake system for an internal combustion engine

A throttle valve control system comprises an accelerator position sensor for detecting the amount of operation of the accelerator, a throttle valve opening degree determining circuit which receives the output of the accelerator position sensor and determines the opening degree of the throttle valve, and a throttle valve driving device which drives the throttle valve to the position corresponding to the opening degree determined by the throttle valve opening degree determining circuit. The throttle valve opening degree determining circuit is arranged to determine the opening degree of the throttle valve with respect to the amount of operation of the accelerator so that the change in the opening degree of the throttle valve for a given change in the amount of operation of the accelerator is relatively small when the amount of operation of the accelerator is in an intermediate range and is relatively large when the amount of operation of the accelerator is above or below the intermediate range.

Throttle valve control system for internal combustion engine

An automobile engine having a device for increasing the inkage air in idle operation when a load is applied to the engine from equipments associate with the engine. An alternator driven by the engine has a voltage regulator which controls the alternator output in response to a load condition on the alternator by controlling the field current. A control unit is provided to restrict an increase in the field current when an electric load is turned on for a time period required for having the engine output increased.

Engine idling load control means

A fuel supply control system for an automobile engine which comprises fuel increasing device operable in response to an output fed from an acceleration detector for increasing the quantity of fuel to be supplied, and a rate-of-increase adjusting device for adjusting the rate of increase of the fuel to be supplied. The rate of increase of the fuel to be supplied becomes high as the air-fuel ratio of the combustible air-fuel mixture detected shortly before the acceleration is high.

Fuel supply control system for engine

An air-fuel ratio control system for an automobile engine including an intake passage having a throttle valve, and a fuel supply unit, which comprises an air detector for generating an air signal indicative of the quantity of air sucked to the engine through the intake passage, a throttle detector for generating a throttle signal indicative of the opening of the throttle valve, and a control unit operable in response to the signals from the air and throttle detectors for determining the air-fuel ratio of a combustible air-fuel mixture to be supplied to the engine in dependence on the amount of air sucked when a load on the engine is small, but on the opening of the throttle valve when the load on the engine is great.

Air-fuel ratio control for internal combustion engine

An engine intake system includes a combustion chamber, a first intake port opening to the combustion chamber, and a second intake port opening to the combustion chamber. A shut-off valve is provided for blocking intake gas flow to the combustion chamber through the second intake port in a first engine operating region wherein engine load is relatively small, and allowing the intake gas to flow to the combustion chamber through the second intake port in a second engine operating region wherein the engine load is relatively large. A first valve actuating mechanism is provided for opening the first intake valve at a first timing, and a second valve actuating mechanism is provided for opening the second intake valve at a second timing. A valve timing changing device is provided for changing the first timing with respect to the second timing so that the first intake valve is closed later than the second intake valve in the second engine operating region, and so that the first intake valve is closed at least in a certain engine operating zone in the first engine operating region at a timing which is more advanced than the timing at which the first intake valve is closed in the second engine operating region.

Valve timing control for internal combustion engines

A multiple cylinder engine including a first group of cylinders having a first intake passage which is provided with a air-fuel mixture of a predetermined ratio in accordance with the signal from an exhaust gas sensor provided in the exhaust passage from the first group of cylinders. The engine further includes a second group of cylinders having a second intake passage which is provided with a mixture having an air-fuel ratio which is of a predetermined relationship with respect to the air-fuel ratio of the mixture provided to the first group of cylinders, the predetermined relationship being determined in accordance the engine operating condition. Check valves are provided in the intake passages to prevent the mixture in the first intake passage from being mixed with that in the second intake passage so that accurate control can be ensured.

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Hiroshima, Japan

Toshio Nishikawa