Hitachi, Ltd.

Hitachi Car Engineering Co., Ltd.

Hitachi Automotive Systems, Ltd.

Other

Eisaku Fukuchi

Akihito Numata

Toshio Ishii

Takanobu Ichihara

Yutaka Takaku

Shinji Nakagawa

Toshihiro Aono

Rogelio B Agustin

Toshio Hori

Yoichi Iihoshi

Yoshikuni Kurashima

Kenichi Kotabe

Kenji Mizushima

Heikichi Kamoshita

Ryusei Miura

Heikichi Kamoshida

It is possible to prevent the stability of an engine from deteriorating even when degrees of changes over time of injection characteristics are different in each fuel injection valve. An inter-cylinder air-fuel ratio variation detection unitcalculates an air-fuel ratio variation index (Ind_imb) which indicates a degree of variation in an air-fuel ratio between cylinders from an exhaust air-fuel ratio, engine rotation speed, or the like. Unlike in a case where the air-fuel ratio variation index (Ind_imb) is lower than a set value, when the air-fuel ratio variation index (Ind_imb) is higher than the set value, a fuel injection pulse width limitation unitsets a (allowable) minimum value (Min_TI) of a fuel injection pulse width so as to be greater. In addition, a fuel injection pulse width calculation unitcalculates fuel injection pulse widths (TI_1, TI_2, TI_3, and TI_4) of cylinders so as not to be lower than the minimum value (Min_TI).

Control device and control method of engine

A control device of an engine includes means for detecting an efficiency of the engine, means for detecting a combustion stability of the engine, means for detecting an HC discharged quantity, and means for executing a notification. The notification is executed when the efficiency of the engine and the combustion stability of the engine do not fall in a predetermined region A. The predetermined region Ais a range of the efficiency of the engine and the combustion stability of the engine. The HC discharged quantity at the time of engine start is a predetermined value or less.

Control device of engine

An anomaly in a high-pressure fuel system of an internal combustion engine is diagnosed early on and with high precision, and, further, the anomaly site is identified. With respect to a diagnostic device for a direct injection internal combustion engine, there is provided: an injection correction amount computation means () that computes an injection correction amount so as to bring a detected air-fuel ratio to a target air-fuel ratio; a fuel injection valve control means () that controls the fuel injection valves with the fuel injection amount corrected based on the injection correction amount; a discharge correction amount computation means () that computes a discharge correction amount so as to bring a detected fuel pressure to a target fuel pressure; a fuel pump control means () that controls the fuel pump with the discharge amount corrected based on the discharge correction amount; a fuel pressure value shifting means () that shifts the value of the detected fuel pressure if the injection correction amount deviates from a predetermined range and until the injection correction amount converges to a given amount within the predetermined range; and an anomaly determination means () that determines which of the fuel pump, the fuel injection valves, and the fuel pressure sensor has an anomaly based on the discharge correction amounts before the fuel pressure values shift starts and after the fuel pressure value shift ends, and on the injection correction amount before the fuel pressure value shift starts.

Diagnostic device for internal-combustion engine

Disclosed is a diagnostic control apparatus for internal combustion engines capable of accurately diagnosing the presence and extent of air/fuel ratio variations in engine cylinders, even when the system has no part for detecting the air/fuel ratio in each cylinder. The diagnostic control apparatus measures the time required for the crankshaft to rotate to a specified angle for each cylinder; and based on this measured, required time, derives the 0.5 order component as the rotation fluctuation component for each two rotations of the crankshaft per each cylinder or the 1.0 order component as the rotation fluctuation component for each single rotation of the crankshaft; and also counts the number of times the 0.5 order component or 1.0 order component deviates from the preset range in the period set for each cylinder, and diagnoses an error in the output or in the air/fuel ratio for a particular cylinder when that count value exceeds a specified value.

Diagnostic control apparatus for internal combustion engines

In an apparatus for diagnosing an exhaust gas purifying device, a catalyst deterioration level detectordetects the deterioration level of a catalyst from a relationship between a catalyst-upstream air-fuel-ratio detectorand a catalyst-downstream air-fuel-ratio detector. A catalyst-deterioration-level correction sectioncorrects the catalyst deterioration level detected by the catalyst deterioration level detectorbased on a falling response ratio representing the ratio between a falling response index of the catalyst-upstream air-fuel-ratio detectorand a falling response index of the catalyst-downstream air-fuel-ratio detectoror based on a rising response ratio representing the ratio between a rising response index of the catalyst-upstream air-fuel-ratio detectorand a rising response index of the catalyst-downstream air-fuel-ratio detector. A catalyst deterioration judgment sectiondetermines that the catalyst is deteriorated from information provided by the catalyst-deterioration-level correction section. This allows any deteriorated catalyst to be precisely detected even if an air-fuel ratio sensor downstream of the catalyst is degraded in terms of rising response.

Apparatus for diagnosing exhaust gas purifying device

When a fuel cut command is issued, a time required for a crankshaft of each cylinder to rotate through a certain angle is stored in one memory per cylinder. In a stage of engine production, a combustion variation per cylinder is stored in another memory. When fuel is supplied, a particular component is extracted from a value obtained by subtracting the sum of the time required for the rotation in a non-combustion state and the combustion variation from the time required for the rotation corresponding to a cylinder determined to be in a combustion stroke. The occurrence of a misfire is determined when the extracted particular component exceeds a threshold.

Misfire detection system for internal combustion engine

A misfire detector is provided that is accurate even in the case of a disturbance due to causes such as driving on a rough road. The misfire detector is equipped with a crankshaft revolution detector to measure the time period required for the crankshaft of an internal-combustion engine to revolve for a given angle. A signal-processor is also provided for detecting the misfiring of the internal-combustion engine by processing the time period. In one embodiment, the misfire detector has two filters having the same sensitivity to the misfire frequency, and differing in the sensitivity to frequencies adjacent to said misfire frequency. It can be determined that a misfire has occurred if the ratio or difference between the outputs of the two filters stays within a fixed range and one or both of the filters have respective outputs exceeding a threshold value.

Misfire detector

A combustion state detection system for an internal combustion engine, in which the engine combustion state is detected by the combustion state parameter calculated from a time signal associated with the rotation of the crankshaft by a predetermined angle. The system comprises a device for compensating for the combustion state parameter and a combustion state parameter compensating permitting condition determining device for permitting or inhibiting the execution of the combustion state parameter compensation device.

Combustion state detection system for internal combustion engine

A diagnostic apparatus for exhaust gas clarification apparatus for internal combustion engine diagnoses the individual catalyst independently by an air/fuel ratio sensor mounted before and after the individual catalyst. The individual catalyst is diagnosed by estimating the correlation of the output signals from the air/fuel ratio sensors mounted before and after the individual catalyst. The individual diagnosis operation is performed at distinctive operation regions adequate for their corresponding diagnostic mode. A by-pass route is provided for by-passing the exhaust gas from the upstream catalyst, and a by-pass valve switches the exhaust gas flow into the upstream catalyst or into the by-pass routes. A cross-correlation function calculation valve based upon outputs from air/fuel ratio sensors permits diagnosis of degradation of the overall catalyst.

Diagnostic apparatus for exhaust gas clarification apparatus for

In an apparatus of detecting a combustion state of an internal combustion engine, a combustion parameter value of the engine is calculated on the basis of measurement data concerning an engine speed, the value of the data concerning the engine speed is corrected with a correction value, the correction value is calculated to make the calculated combustion parameter fall within a predetermined range, and the correction value is set to a predetermined value when a predetermined condition is satisfied.

Apparatus and method of detecting combustion state of internal

A combustion state detection system for an internal combustion engine in which a timing signal associated with the rotation of the crankshaft by a predetermined angle is detected and corrected, and a combustion state parameter is calculated from the timing signal. Further, the deviation of the calculated combustion state parameters for normal combustion is detected between the cylinders, and the correction amount of the timing signal is calculated. A reference cylinder is determined by the means for detecting the deviation. The deviation is detected between the combustion state parameter for normal combustion of the reference cylinder and the cylinder opposed thereto and the combustion state parameter for normal combustion of the remaining cylinders. The correction amount is calculated in such a manner as to control the correction amount to not more than a predetermined value or to zero from the detected deviation.

It is intended to detect combustion state of an internal combustion engine over the entire range where positive torque is generated. Time required from a predetermined first crank angle to a second crank angle is measured by detecting a rotation angle of a ring gear or plate with engine speed detecting means 101. Then, a combustion state parameter is calculated from said required time by combustion state detecting means 102 with an established calculation method, and combustion state is determined by combustion state judging means 103. Engine speed correction means 104 determines and feeds back a correction value for the combustion state detecting value to correct the engine speed. At the moment, the correction quantity for correcting the required time is varied so that the normal combustion value of said combustion state parameter is at a predetermined value or less, or within a predetermined range. When the combustion state parameter reaches a value indicating misfire, update of the correction value is inhibited for a prescribed duration before and after it.

Detector device for combustion state in internal combustion engine

A diagnostic apparatus for exhaust gas clarification apparatus for internal combustion engine is disclosed. The diagnostic apparatus can diagnoses the individual catalyst independently by means that an air/fuel ratio sensor is mounted before and after the individual catalyst, and that the individual catalyst is diagnosed by estimating the correlation of the output signals from the air/fuel ratio sensors mounted before and after the individual catalyst, and furthermore, that the individual diangosis operation is performed at distinctive operation regions adequate for their corresponding diagnostic mode.

Growing community of inventors

Mito, Japan

Eisaku Fukuchi