Toyota Jidosha Kabushiki Kaisha

Daisuke Shibata

Hiroshi Sawada

Toru Kidokoro

Kazuya Takaoka

Taiga Hagimoto

Masaaki Kobayashi

Yuji Miyoshi

Naofumi Magarida

Shinobu Ishiyama

Hisashi Ohki

Keisuke Fukuoka

Kazuhiro Wakao

Hiroki Matsuoka

Makoto Ogiso

Tomihisa Oda

Kotaro Hayashi

Masaaki Yamaguchi

Tomoyuki Ono

Souichi Matsushita

Keisuke Sano

Koichi Kitaura

Kimikazu Yoda

Shinichiro Imamura

Yasuo Harada

Kazumasa Shimode

Satoshi Endo

Yukihiro Tsukasaki

Akihiko Negami

Yasuhiro Ohtsubo

Tatsuya Tsuji

Satoru Maeda

Akihiro Negami

Akihiko Itakura

Yasuyuki Yokokawa

Yasuhiko Ohtsubo

Takahiro Ohba

Apparatus for detecting deterioration of an NOx selective reduction catalyst in an exhaust passage of an internal combustion engine with improved accuracy, includes an NOx purification rate calculation unit for calculating the NOx purification rate in the NOx selective reduction catalyst based on the NOx concentration in the exhaust gas flowing into and out of the NOx selective reduction catalyst. A determination as to whether the NOx selective reduction catalyst is deteriorated is made based on the NOx purification rate at a time when the temperature of the NOx selective reduction catalyst is equal to or higher than a temperature (Tc) at which the NOx purification rate will start to decrease with a rise in the temperature of the NOx selective reduction catalyst if the degree of deterioration of the NOx selective reduction catalyst is at the upper limit of an allowable range.

Apparatus for detecting deterioration of NOx selective reduction catalyst

An exhaust gas purification apparatus including a filter, an NOx selective reduction catalyst at the downstream side of the filter, a supply device for supplying a reducing agent to the NOx selective reduction catalyst, and a PM sensor for detecting an amount of particulate matter in an exhaust gas at the downstream side of the NOx selective reduction catalyst. A supply decrease part makes an amount of supply of the reducing agent smaller in cases where at least one of several conditions is satisfied.

Exhaust gas purification apparatus for an internal combustion engine

A reduction in the accuracy of a failure determination of a filter due to a reduction in the detection accuracy of a PM sensor is suppressed. To this end, provision is made for an NOx selective reduction catalyst arranged in an exhaust passage of the internal combustion engine to reduce NOx by means of a reducing agent supplied thereto, a supply device to supply urea water as the reducing agent from an upstream side of the NOx selective reduction catalyst, a PM sensor to detect an amount of particulate matter in an exhaust gas at the downstream side of the NOx selective reduction catalyst, and a control unit to make an amount of production of intermediate products from the urea water supplied from the supply device to ammonia smaller when an amount of particulate matter is detected by the PM sensor than when not detected.

A reduction in the accuracy of a failure determination of a filter due to a reduction in the detection accuracy of a PM sensor is suppressed. In order to achieve this, provision is made for a filter that is arranged in an exhaust passage of an internal combustion engine for trapping particulate matter contained in an exhaust gas, an NOx selective reduction catalyst that is arranged at the downstream side of the filter and reduces NOx by means of a reducing agent which is supplied thereto, a supply device that supplies the reducing agent to the NOx selective reduction catalyst from the upstream side of the NOx selective reduction catalyst, a PM sensor that detects an amount of the particulate matter in the exhaust gas at the downstream side of the NOx selective reduction catalyst, and a prohibition part that prohibits the use of a detected value of the PM sensor in cases where the reducing agent supplied from said supply device passes through the NOx selective reduction catalyst.

A warm-up system for an exhaust system of an internal combustion engine includes an electronic control unit that performs warm-up control for warming up an exhaust system component upon start-up of the internal combustion engine and a failure diagnosis performing module of the electronic control unit that performs failure diagnosis for the exhaust system component after the completion of warm-up of the exhaust system component. If the internal combustion engine repeatedly stops before completion of the failure diagnosis for a predetermined period of time, then the electronic control unit changes the warm-up control performed upon start-up of the internal combustion engine to a control that raises the temperature of the exhaust system component more quickly than the warm-up control performed during the predetermined period.

Warm-up system for exhaust system of internal combustion engine

An object of the present invention is to detect any breakdown or failure of a particulate filter more appropriately. A failure detecting apparatus for detecting failure of a particulate filter according to the present invention comprises an acquiring section which acquires an amount of PM contained in an exhaust gas allowed to outflow from the particulate filter; a regeneration process executing section which executes a filter regeneration process for oxidizing and removing PM deposited in the particulate filter; and a failure judging section which judges that the particulate filter is in the failure state if a decreased amount of the amount of PM contained in the exhaust gas acquired by the acquiring section, during a predetermined period of time as started from a point in time at which the execution of the filter regeneration process performed by the regeneration process executing section is completed, is not equal to or larger than a predetermined reference amount.

Failure detecting apparatus for particulate filter

It is determined quickly whether there is a shortage in reducing agent supplied to an NOx selective reduction catalyst. After it is determined that a quantity of reducing agent equal to or larger than a predetermined quantity is absorbed in the NOx selective reduction catalyst on the assumption that there is no abnormality in reducing agent supply unit, the supply of a quantity of reducing agent needed to reduce a quantity of NOx flowing into the NOx selective reduction catalyst is started. A determination of an abnormality in the reducing agent supply unit is made based on the NOx removal rate after the lapse of a predetermined period of time since the start of the supply of reducing agent. The NOx removal rate becomes lower when there is an abnormality in the reducing agent supply unit.

Abnormality detection apparatus for exhaust gas purification apparatus and abnormality detection method for exhaust gas purification apparatus

The present invention is intended to detect a failure of a PM filter with a higher degree of accuracy. The present invention is provided with: a PM trapping efficiency calculation part to calculate a PM trapping efficiency (which is a proportion of an amount of particulate matter trapped with respect to an amount of inflow particulate matter) based on an amount of inflow particulate matter obtained by an inflow particulate matter obtaining part, and an amount of outflow particulate matter detected by a PM sensor; and a failure detection part to make a determination that a failure has occurred in the PM filter, in cases where there has appeared a tendency for the PM trapping efficiency to decrease during a period of time until the execution of the following filter regeneration processing is started after the completion of execution of the filter regeneration processing.

Failure detection apparatus and failure detection method for a particulate filter

Provision is made for a catalyst that is arranged in an exhaust passage of an internal combustion engine and has an oxidation function, downstream side temperature detection means that detects the temperature of an exhaust gas at a downstream side from the catalyst, and addition means that adds a reducing agent into the exhaust gas from an upstream side from the catalyst, wherein there are also provided correlation value calculation means that calculates a correlation value which is correlated with an amount of change of the temperature detected by the downstream side temperature detection means when the reducing agent is added by the addition means and when a transient operation of the internal combustion engine is carried out, and determination means that determines a deterioration of the catalyst by making a comparison between the correlation value and a threshold value which indicates the deterioration of the catalyst.

Catalyst deterioration detection apparatus and catalyst deterioration detection method for internal combustion engine

A failure of a filter is detected with a higher degree of accuracy. There are provided a filter that is arranged on an exhaust passage of an internal combustion engine for collecting a substance contained in an exhaust gas, a substance amount detection part that is arranged on the exhaust passage at a downstream side of the filter for detecting an amount of substance in the exhaust gas, a flow speed detection part that detects or estimates a flow speed of the exhaust gas which passes through the filter, and a determination part that makes a determination that the filter is in a failure, when the higher the flow speed of the exhaust gas passing through the filter, the larger a ratio of an amount of change in the amount of substance to an amount of change in the flow speed of the exhaust gas becomes.

Filter failure detection apparatus of an internal combustion engine

An object of the present invention is to provide a technology that enables detection of a fault of a PM trapper with improved accuracy. In the present invention, a pressure sensorthat measures a differential pressure across a PM trapperis provided, and a fault of a PM trapper is determined based on an amount of change in the differential pressure across the PM trapperbetween two different operation states of an internal combustion enginein which the ambient temperature around the pressure sensorfalls within a specific temperature range. Since variations in the offset error of the differential pressure sensorcaused by changes in the ambient temperature around the differential pressure sensoris made small, the amount of change in the differential pressure across the PM trappercan be measured more accurately, and a fault of the PM trappercan be detected with improved accuracy.

Fault detection system for PM trapper

A catalyst deterioration diagnosis system performs a diagnosis of deterioration of the oxidation catalyst based on a high-temperature-inflow-condition exhaust gas temperature and a low-temperature-inflow-condition exhaust gas temperature. The high-temperature-inflow-condition exhaust gas temperature is a temperature detected by a temperature sensor while the temperature of the exhaust gas that flows into the oxidation catalyst is in a high temperature region H while the reducing agent is supplied from the reducing agent supply means into the exhaust gas that flows into the oxidation catalyst. The low-temperature-inflow-condition exhaust gas temperature is a temperature detected by the temperature sensor while the temperature of the exhaust gas that flows into the oxidation catalyst is in a low temperature region L while the reducing agent is supplied from a reducing agent supply means into the exhaust gas that flows into the oxidation catalyst.

Catalyst deterioration diagnosis system and method for internal combustion engine

The invention intends to provide a technology which makes it possible to diagnose with higher accuracy whether or not abnormality occurs in a filter regeneration system causing excessive execution frequency of a regeneration process. The filter regeneration system initiates execution of the regeneration process, incase an estimated particulate matter (PM) accumulation amount at the filter reaches a pre-determined regeneration requiring accumulation amount; or in case the pressure upstream of the filter or the differential pressure across the filter reaches a pre-determined regeneration requiring value, the value being larger than the pressure or the differential pressure corresponding to the regeneration requiring accumulation amount. Then, the diagnosis is carried out based on a ratio of an estimated PM accumulation amount at the initiation of the execution of the regeneration process to the regeneration requiring accumulation amount.

Abnormality diagnosis system and method for diagnosing abnormality in filter regeneration system

The degree of deterioration of a catalyst is obtained accurately in cases where a plurality of catalysts is disposed at an exhaust passage of an internal combustion engine. Under the assumption that the degree of deterioration of a catalyst which is disposed at a location upstream of an NOselective reduction catalyst and has an oxidizing ability is at a predetermined value, the ratio of NOin the NOwhich inflows into the NOselective reduction catalyst is estimated; the NOremoval rate of the NOselective reduction catalyst is calculated a plurality of times at least until a local maximum value is obtained; and the degree of deterioration of the catalyst having an oxidizing ability is determined by comparison between the ratio of NOobserved when the NOremoval rate of the NOselective reduction catalyst reaches the local maximum value and a reference value of the ratio.

Device for determining deterioration of catalyst and method for determining deterioration of catalyst

An exhaust passage () of an internal-combustion engine () includes a selective reduction NOx catalyst () and an after-catalyst NOx sensor () for detecting a NOx concentration Cr at the downstream thereof. Reducing agent is selectively added from an addition valve () to the NOx catalyst. A NOx concentration Ce at the upstream side of the NOx catalyst is detected or estimated. NOx concentrations Cr and Ce before and after the NOx catalyst, which were detected or estimated during the stoppage of an addition of the reducing agent, are compared to each other to thereby determine an abnormality of the after-catalyst NOx sensor (). An abnormality diagnosis is executed while the addition of reducing agent is being stopped to remove an influence by the NOx catalyst.

Growing community of inventors

Numazu, Japan

Daisuke Shibata