Toyota Jidosha Kabushiki Kaisha

Tomoyuki Kogo

Koichiro Nakatani

Taiga Hagimoto

Shinobu Ishiyama

Arifumi Matsumoto

Kenji Furui

Tomoyuki Ono

Katsuhiro Ito

Terutoshi Tomoda

Makoto Ogiso

Kazuya Takaoka

Hirokazu Nishijima

Akifumi Uozumi

Yoshihiro Hisataka

Takashi Ogawa

Michio Furuhashi

Kazuyasu Iwata

Takeshi Hashizume

Masayoshi Nakagawa

Naofumi Magarida

Fumiaki Hattori

Yoshinori Yanase

Yoshiki Yanase

An exhaust control system for an internal combustion engine comprises: a trapping capability acquisition part that obtains information regarding a PM trapping capability, based on a detection value of an exhaust sensor provided to detect a predetermined parameter relating to an exhaust gas flowing out of an SCRF; and a NOx reduction capability acquisition part obtains information regarding a NOx reduction capability, based on an amount of NOx in the exhaust gas flowing out of the SCRF. The exhaust control system determines and distinguishes between a trapping abnormal state in which a PM trapping function by the SCRF is failed and a sensor abnormal state in which a detection function of the predetermined parameter by the exhaust sensor is failed, based on the NOx reduction capability obtained by the NOx reduction capability acquisition part, when the trapping capability obtained by the trapping capability acquisition part is in a predetermined low trapping capability state. This allows for accurate abnormality determination with regard to the SCRF in the exhaust control system for the internal combustion engine having the SCRF.

Exhaust control system for internal combustion engine

A filter abnormality determination system includes: a PM sensor configured to introduce a part of exhaust gas flowing in the exhaust gas passage on the downstream side of a filter into a sensor body and to correlate a sensor output with an amount of particulate matter accumulated on a sensor element in the sensor body; an abnormality determining unit configured to perform filter abnormality determination on the basis of the output of the PM sensor; a determination timing determining unit configured to determine a timing at which the abnormality determining unit performs the abnormality determination on the basis of an estimated amount of particulate matter accumulated on the sensor element; and a determination performing adjusting unit configured to adjust the performing timing determined by the determination timing determining unit depending on a variation of an exhaust gas flow rate per unit time in the exhaust gas passage in which the PM sensor is disposed.

Filter abnormality determination system

A device is provided, which makes it possible to perform a failure diagnostics for a filter more accurately even in the case of an internal combustion engine which is constructed to be capable of using both of gaseous fuel and liquid fuel. The device of the invention comprises judging means which judges any failure of the filter by comparing the added-up amount of the particulate matter contained in the exhaust gas as detected by a PM amount detecting sensor during a predetermined period and the added-up amount of the particulate matter contained in the exhaust gas as estimated by PM amount estimating means during the predetermined period, wherein the PM amount estimating means estimates the added-up amount of the particulate matter contained in the exhaust gas on the basis of the predetermined parameter and only a fuel injection amount of the liquid fuel out of a fuel injection amount of the gaseous fuel and the fuel injection amount of the liquid fuel.

Filter failure diagnostic device for an internal combustion engine

An object of the invention is to suppress a reduction in accuracy of abnormality diagnosis with an abnormality diagnosis device for an exhaust gas control apparatus that performs the abnormality diagnosis regarding the exhaust gas control apparatus by using the amount of NOflowing into an SCR catalyst as a parameter. In the abnormality diagnosis device for an exhaust gas control apparatus according to the invention provided with an exhaust gas control apparatus including the SCR catalyst, a supply device supplying ammonia to the exhaust gas control apparatus, an EGR device allowing some of exhaust gas to flow back to an intake passage from an exhaust passage further downstream than the supply device, acquiring means for acquiring a NOinflow amount as the amount of NOflowing into the exhaust gas control apparatus, and diagnostic means for diagnosing an abnormality of the exhaust gas control apparatus by using the NOinflow amount acquired by the acquiring means as a parameter, the abnormality diagnosis regarding the exhaust gas control apparatus by the diagnostic means is prohibited in a case where the amount of the ammonia allowed to flow back along with the exhaust gas by the EGR device exceeds an upper limit value.

Abnormality diagnosis device for exhaust gas control apparatus

An abnormality diagnosis apparatus includes an exhaust gas purification apparatus arranged in an exhaust passage of an internal combustion engine and including a SCR catalyst; a supply apparatus supplying an additive such as ammonia to the exhaust gas purification apparatus; an EGR apparatus recirculating a part of exhaust gas from the exhaust passage at a downstream side of a position of supplying the additive to an intake passage; obtaining means for obtaining a NOinflow amount into the exhaust gas purification apparatus; diagnosing means for calculating a physical quantity correlated to a NOpurification performance of the exhaust gas purification apparatus using the obtained NOinflow amount, and diagnosing that an abnormality has occurred in the exhaust gas purification apparatus when the physical quantity is smaller than a threshold; and correcting means for, when the additive is recirculated together with a part of the exhaust gas, correcting the threshold to a smaller value than when otherwise.

Abnormality diagnosis apparatus of exhaust gas purification apparatus

An incorrect or wrong diagnosis in abnormality diagnosis of a sensor is suppressed. Provided at the downstream side of an NOx selective reduction catalyst is a sensor which detects NOx and ammonia in an exhaust gas flowing out of the NOx selective reduction catalyst, and in which the NOx and the ammonia react with each other. An amount of decrease in an output of the sensor due to a reaction of the NOx and the ammonia in the sensor is calculated based on the NOx and the ammonia flowing out of the NOx catalyst, and an abnormality diagnosis of the sensor is carried out based on this amount of decrease in the output of the sensor.

Abnormality diagnosis device for a sensor

An abnormality diagnosis apparatus includes: an exhaust gas purification apparatus arranged in an exhaust passage of an internal combustion engine and including a selective catalytic reduction catalyst; a supply apparatus supplying an additive such as ammonia to the exhaust gas purification apparatus; an EGR apparatus recirculating a part of exhaust gas from the exhaust passage at a downstream side of a position of supplying the additive to an intake passage; calculating means for calculating a NOinflow amount into the exhaust gas purification apparatus using a parameter indicating an operating state of the internal combustion engine; diagnosing means for diagnosing an abnormality in the exhaust gas purification apparatus using the calculated NOinflow amount as a parameter; and correcting means for, when a part of the exhaust gas is recirculated, increasingly correcting the calculated NOinflow amount in accordance with an amount of the additive to be recirculated together with exhaust gas.

A diagnostic apparatus for an exhaust gas purification apparatus including a selective catalytic reduction NOx catalyst (SCR catalyst) provided in an exhaust passage of an internal combustion engine, a supplying unit supplying ammonia or an ammonia precursor into exhaust gas flowing into the SCR catalyst and a sensor, provided on a downstream side of the SCR catalyst, detecting NOx and ammonia in exhaust gas. The diagnostic apparatus calculates an amount of decline in output of the sensor due to a reaction between NOx and ammonia at the sensor and performs a diagnosis of the supplying unit based on the calculated amount of decline in output of the sensor.

Diagnostic apparatus for exhaust gas purification apparatus

An abnormality diagnosis apparatus for an exhaust gas purification apparatus including a selective catalytic reduction NOx catalyst (SCR catalyst) and a sensor which detects NOx and ammonia in exhaust gas flowing out from the NOx catalyst and at which NOx and ammonia react with each other. The abnormality diagnosis apparatus calculates, based on concentrations of NOx and ammonia which flow out from the SCR catalyst, an amount of decline in output of the sensor due to a reaction between NOx and ammonia at the sensor, and performs an abnormality diagnosis of the SCR catalyst based on the calculated amount of decline in output of the sensor.

Abnormality diagnosis apparatus for exhaust gas purification apparatus

A control device includes: a first phase changing portion retarding a first intake valve phase relative to a second intake valve phase; a throttle valve adjusting an intake air amount of the engine, and a control portion configured to perform an intake valve phase control which controls the first phase changing portion to retard the first intake valve phase relative to the second intake valve phase such that an air amount in the cylinder of the engine is reduced to a target value to perform rich combustion, and the control portion configured to perform a throttle valve closing control which controls the throttle valve such that the air amount in the cylinder is the target value or smaller after the air amount in the cylinder is not reduced to the target value or smaller by the intake valve phase control performed by the first phase changing portion.

Control device for changing phase of multiple independent intake valves in engine

A control apparatus for an internal combustion engine includes phase change means () for advancing or retarding phases of an opening timing and a closing timing of an intake valve (); duration change means () for increasing or decreasing a duration of the intake valve (); and EGR gas amount increase means () for increasing an amount of EGR gas, based on an operating state of an internal combustion engine. The control apparatus further includes intake-valve closing timing advancing means () for advancing the intake-valve closing timing when the amount of EGR gas is increased. The intake-valve closing timing advancing means () advances the intake-valve closing timing by performing a first operation that advances the phases using the phase change means (), and performing a second operation that decreases the duration using the duration change means (), and makes a timing at which the second operation is started later than a timing at which the first operation is started.

Control apparatus and control method for internal combustion engine

In an exhaust gas control apparatus for an internal combustion engine, including a supercharger which is provided in an exhaust passage at a position up-stream of a catalyst having an oxidizing ability; turbine rotation energy amount adjusting means () for adjusting an amount of energy of exhaust gas, which is used for rotating the turbine of the supercharger; and after-injection performing means for performing after-injection, when a work amount of the compressor is increased by the after-injection, the turbine rotation energy amount adjusting means decreases the amount of energy of the exhaust gas, which is used for rotating the turbine, in order to decrease the increased work amount to zero.

Exhaust gas control apparatus and exhaust gas control method for internal combustion engine

Disclosed is a technology that enables better reduction of NOx stored in an NOx catalyst in an exhaust gas purification system for an internal combustion engine. When NOx stored in an NOx catalyst is to be reduced, the air-fuel ratio of the ambient atmosphere around the NOx catalyst is decreased to a target air-fuel ratio by decreasing the air-fuel ratio of the exhaust gas discharged from the internal combustion engine. In doing so, if the temperature of the NOx catalyst is not lower than a specific temperature, the air-fuel ratio of the ambient atmosphere around the NOx catalyst is decreased to the target air-fuel ratio while bringing the combustion state into low temperature combustion. On the other hand, if the temperature of the NOx catalyst is lower than the specific temperature, the air-fuel ratio of the ambient atmosphere around the NOx catalyst is decreased to the target air-fuel ratio while decreasing the quantity of EGR gas in a cylinder so that the amount of generated smoke is kept within an allowable range.

Exhaust gas purification system for internal combustion engine

An object of the present invention is to provide a technology that enables reduction of NOx stored in an NOx catalyst with improved efficiency in an exhaust gas purification system for an internal combustion engine. According to the present invention, when NOx stored in the NOx catalyst is to be reduced, if the temperature of the NOx catalyst is lower than a specific temperature, the air-fuel ratio of the ambient atmosphere around the NOx catalyst is decreased only by decreasing the air-fuel ratio of the exhaust gas discharged from the internal combustion engine, and if the temperature of the NOx catalyst is not lower than the specific temperature, the air-fuel ratio of the ambient atmosphere around the NOx catalyst is decreased either only by adding reducing agent through reducing agent addition means, or by decreasing the air-fuel ratio of the exhaust gas discharged from the internal combustion engine and adding reducing agent through the reducing agent addition means.

A control apparatus for an internal combustion engine () includes intake valve control means (). The internal combustion engine () includes a variable intake valve operating mechanism () that changes a valve opening characteristic of an intake valve (), and rich combustion is performed in the internal combustion engine () to control an exhaust gas purification catalyst () disposed in an exhaust passage (). The intake valve control means () controls the valve opening characteristic of the intake valve () to increase a flow rate of intake air in an early stage of an intake stroke when the rich combustion is performed, as compared to when non-rich combustion is performed.

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Gotenba, Japan

Tomoyuki Kogo