Toyota Jidosha Kabushiki Kaisha

Takeshi Genko

Masanao Idogawa

Daigo Ando

Takahiro Nishigaki

Tsukasa Abe

Shinya Kondo

Ikuo Ando

Yosuke Matsumoto

Kenya Maruyama

Takamitsu Mizutani

Chisa Watanabe

Yusuke Joh

Yousuke Matsumoto

A controller for an internal combustion engine is configured to execute a rich air-fuel ratio control for performing fuel injection while setting a target equivalence ratio such that, at recovery from a fuel cutoff process, an air-fuel ratio of air-fuel mixture is richer than a stoichiometric air-fuel ratio. The controller is configured to execute a target equivalence ratio setting process for setting the target equivalence ratio that is maintained during execution of the rich air-fuel ratio control such that the target equivalence ratio increases as an air excess ratio that is calculated from an output value of a second air-fuel ratio sensor at start of the rich air-fuel ratio control increases.

Controller for internal combustion engine

An engine system includes an engine that, a fuel supply device, and an electronic control unit. The electronic control unit is configured to control the fuel supply device and to perform operation control of the engine by adjusting an injection ratio between fuel injection from an in-cylinder injection valve and a port injection valve according to the operation state of the engine. The electronic control unit is configured to perform imbalance determination. The electronic control unit is configured to change a region of fuel injection from a first fuel injection region to a second fuel injection region when the electronic control unit determines that a lean imbalance is occurred with respect to the fuel injection in which the fuel injection from the port injection valve is performed.

Engine system and control method for engine system

An engine system includes an engine, an atmospheric pressure sensor, an intake pressure sensor, and an electronic control unit. The electronic control unit is configured to execute atmospheric pressure learning for learning a relation between atmospheric pressure and an intake air amount of the engine based on the atmospheric pressure detected by the atmospheric pressure sensor, and execute fuel injection control of the engine using an initial value of an intake air amount model obtained based on the atmospheric pressure learning. The electronic control unit is configured to execute the fuel injection control of the engine using an initial value of the intake air amount model obtained based on the intake pressure detected by the intake pressure sensor, when rotational speed of the engine is less than a specified rotational speed at start of the fuel injection control of the engine.

An internal combustion engine executes EGR and controls the air-fuel ratio based on a detected oxygen concentration in the exhaust. An electronic control unit controls the engine such that the detected value for the air-fuel ratio upstream from a front catalyst provided in an exhaust pipe reaches a value indicating a leaner air-fuel ratio when EGR is being executed than when not executed. Therefore, the controlled air-fuel ratio follows shifting of a window to the leaner side in response to execution of EGR, so that the air-fuel ratio is controlled more precisely in response to the execution of EGR.

Control device for internal combustion engine

An air-fuel ratio imbalance determination apparatus for a multi-cylinder internal combustion engine includes an air-fuel ratio sensor with a catalyst layer disposed in an exhaust passage of the multi-cylinder internal combustion engine; and a control unit configured: to perform determination regarding an air-fuel ratio imbalance state among cylinders of the multi-cylinder internal combustion engine based on an amount of change per unit time in an air-fuel ratio detected by the air-fuel ratio sensor; to execute an air-fuel ratio enrichment control using an air-fuel ratio enrichment amount; and to correct a learned imbalance value when the air-fuel ratio enrichment amount is smaller than a predetermined determination threshold value in a case where an engine operation state is in an imbalance learning range during execution of the air-fuel ratio enrichment control.

Air-fuel ratio imbalance determination apparatus and air-fuel ratio imbalance determination method

A vehicle includes an internal combustion engine, an air-fuel ratio sensor provided in an exhaust passage of the internal combustion engine, and a controller. The controller is configured to diagnose a responsiveness of the air-fuel ratio sensor on the basis of an output voltage of the air-fuel ratio sensor in a predefined period. The period is a period over which exhaust gas goes through the air-fuel ratio sensor during the internal combustion engine is rotating without fuel injection.

Vehicle and control method of vehicle

An air-fuel ratio control system of an internal combustion engine includes a controller that performs air-fuel ratio feedback control through main feedback control and sub feedback control based on the concentrations of oxygen in exhaust gas upstream and downstream of a catalyst respectively, and the controller stores a constant component of a sub feedback correction value of the sub feedback control as a sub feedback learned value, and sets a feedback target value of the main feedback control to values that are different depending on whether or not exhaust gas is recirculated into intake air. When the constant component of the sub feedback correction value obtained when the amount of recirculated exhaust gas is short of its required amount is stored as the sub feedback learned value, the controller corrects the feedback target value of the main feedback control when the recirculation of exhaust gas is not conducted.

Air-fuel ratio control system of internal combustion engine

The invention relates to an air-fuel ratio control device of an internal combustion engine, comprising a plurality of means for independently introducing into each combustion chamber an exhaust gas discharged from combustion chambers to an exhaust passage. When at least one exhaust gas introduction means is under an exhaust gas introduction shortage state, a target value of an air-fuel ratio of a mixture gas is changed depending on whether an exhaust gas introduction control for introducing the exhaust gas into the combustion chamber by the exhaust gas introduction means is performed.

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Toyota, Japan

Takeshi Genko