Toyota Jidosha Kabushiki Kaisha

Hiroaki Tsuji

Yuya Yoshikawa

Masashi Hakariya

Tokiji Ito

Yoshihisa Oda

Isao Nakajima

Yoshifumi Matsuda

Toshihiro Kato

Masahide Okada

Takeo Ogiso

Keiko Okamoto

Kenji Kimura

Akihiro Katayama

Shuntaro Okazaki

Naoto Kato

Tatsuro Shimada

A control device of an internal combustion engine according to the present invention executes air-fuel ratio control based on an output of an air-fuel ratio sensor provided at an upstream side of a catalyst, with correction based on an output of an oxygen sensor at a downstream side of the catalyst. When it is determined that a degree of an output tendency in a predetermined lean region is not less than a predetermined lean degree, and that a degree of an output tendency in a predetermined rich region is less than a predetermined rich degree based on lean tendency and rich tendency values representing output tendencies of the oxygen sensor, a limit is set to the correction in a direction to more suppress enriching of an air-fuel ratio as a degree is larger in which the output of the oxygen sensor is shifted to a lean side.

Control device of internal combustion engine

An air-fuel ratio control apparatus for an internal combustion engine is provided. A controller is programmed to perform correction amount guard control allowing adjustment of a correction amount by setting a limit on the correction amount when an appearance frequency of a state where an output value from a downstream sensor is leaner than a predetermined value is equal to or higher than a predetermined value. When a state where the output value from the downstream sensor is leaner than the predetermined value lasts for a duration equal to or longer than a predetermined time, an incorporation speed at which, during learning control, the correction amount for sub feedback control is incorporated into a learning value is set to a larger value that when the duration is shorter than the predetermined time, and performance of the correction amount guard control is suppressed until the learning control is completed.

Air-fuel ratio control apparatus for internal combustion engine

An abnormality detecting device of an internal combustion engine according to the present invention includes a sensor nick abnormality detecting unit configured to detect a nick abnormality in a detecting element of a downstream side sensor which is provided in a downstream side of an exhaust gas purifying catalyst in an exhaust passage and generates an output corresponding to an oxygen concentration in exhaust gas, on the basis of a matter that a distribution of an output of the downstream side sensor is biased to an area in which the air-fuel ratio is leaner than a theoretical air-fuel ratio, and an inhibiting unit configured to inhibit detection of the nick abnormality of the detecting element by the sensor nick abnormality detecting unit in the case that an intake air amount exceeds a predetermined amount.

Abnormality detecting device of internal combustion engine

A control device of an internal combustion engine according to the present invention has units configured to inject fuel at a first predetermined ratio from first and second fuel injection valves which are provided in each of cylinders to calculate a first value indicating a degree of variation in air-fuel ratios between the cylinders based on a output of the engine, and inject fuel at a second predetermined ratio therefrom to calculate a second value in the same manner. Furthermore, the control device has a unit configured to select one mode from modes relating to abnormality in the first fuel injection valve or the second fuel injection valve on the basis of the first and second values, and calculate a value indicating the degree of the variation in the air-fuel ratios between the cylinders, thereby calculating a fuel amount of the basis of them.

An abnormality detection apparatus includes: an air/fuel ratio control portion that performs a control of fluctuating the air/fuel ratio between rich and lean states; a data acquisition portion that acquires, as data for detecting abnormality, a parameter that corresponds to responsiveness during change of output of the A/F sensor between rich and lean peaks during the control; a straight line setting portion that sets a straight line that represents a tendency of change of the parameter relative to change in intake air amount of the engine based on the data acquired by performing acquisition of the data a plurality of times; and an abnormality determination portion that determines the presence/absence of abnormality of the A/F sensor based on comparison between the gradient of the set straight line and an abnormality criterion value.

Abnormality detection apparatus and abnormality detection method for air/fuel ratio sensor

An engine ECU calculates a rotational variation based on a required rotation time when a complete misfire occurs in a cylinder, a required rotation time when complete combustion occurs in the cylinder, and a required rotation time during the current combustion stroke, and integrates the calculated rotational variation. If it is determined that the number of times the rotational variation has been integrated has reached a predetermined number, the engine ECU calculates an amount of learning value deviation from the integrated rotational variation. If the amount of learning value deviation is equal to or greater than a certain amount, the engine ECU corrects a learning value of a sub-feedback control with respect to the air-fuel ratio.

Vehicle and vehicle control method

An abnormality detection apparatus includes: an air/fuel ratio control portion that performs a control of fluctuating the air/fuel ratio; a data acquisition portion that acquires, as data for detecting abnormality, a responsiveness parameter while output of the air/fuel ratio sensor changes between rich and lean peaks during the control; an abnormality determination portion that determines presence/absence of abnormality of the sensor by using the data; and a distribution width determination portion that finds a distribution width of the data acquired by performing a plurality of acquisitions of the data, in an increase/decrease direction of the data. On the basis of comparison between the distribution width and an abnormality criterion value, the abnormality determination portion determines that the sensor has abnormality if the distribution width is less than the criterion value, and determines that the sensor does not have abnormality if the distribution width is not less than the criterion value.

An abnormality detection apparatus includes: an air/fuel ratio control portion that controls of fluctuating the air/fuel ratio; a data acquisition portion that acquires a responsiveness parameter during change of output of the sensor between rich and lean peaks; and a abnormality determination portion that when the number of acquisitions reaches or exceeds a first set number, the presence/absence of sensor abnormality based on the average value and the criterion-value is determined, if the average value is not in a pending region; however, if the average value is in the pending region, the data acquisition is performed until the number of acquisitions performed during a large-amount-of-intake-air state of the engine reaches a second set number, and the presence/absence of sensor abnormality based on the average value of the data acquired by the second set number of acquisitions and the criterion-value is determined.

An apparatus includes: an control portion that controls fluctuating the air/fuel ratio; a data acquisition portion that acquires a responsiveness parameter during change of output of the sensor between a rich peak to a lean peak; and a determination portion that determines presence/absence of abnormality of the sensor based on an abnormality criterion value and a data average. When the number of the acquired data becomes equal to or greater than a first number, if the number of the acquired data during a large intake-air-amount of an engine is greater than or equal to a second number, the determination portion determines the presence/absence of abnormality, or if the number of the acquired data during the large intake-air-amount is less than the second number, the determination portion does not determines that, but acquires the data until the number of the acquired data during the large intake-air-amount reaches the second number.

From execution of fuel cut until restoration therefrom in response to a F/C flag being set, an ECU senses an intake air amount Q and engine speed NE, calculates the charging efficiency based on Q and NE, and calculates a basic injection amount TAU_B based on the charging efficiency. When the F/C flag is reset, the ECU calculates asynchronous injection requested amount TAU_REQ based on emission request, calculates upper guard injection amount ASY_MAX based on TAU_B, inserts ASY_MAX into asynchronous injection amount TAU_ASY when TAU_REQ is larger than ASY_MAX and inserts TAU_REQ into asynchronous injection amount TAU_ASY when TAU_REQ is equal to or below ASY_MAX.

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Miyoshi, Japan

Hiroaki Tsuji