Toyota Jidosha Kabushiki Kaisha

Kabushiki Kaisha Toyota Chuo Kenkyusho

Cataler Industrial Co., Ltd.

Toyota Jidosha Kogyo Kabushiki Kaisha

Kenji Katoh

Satoshi Iguchi

Tetsuro Kihara

Takamitsu Asanuma

Shinichi Takeshima

Toshiaki Tanaka

Hiroshi Tanaka

Hideaki Muraki

Tokuta Inoue

Masato Gotoh

Toshio Tanahashi

Takaaki Itou

Kiyoshi Nakanishi

Masato Goto

Hidetaka Nohira

Shinya Hirota

Susumu Kojima

Shinichi Matsumoto

Naoto Suzuki

Kiyohiko Oishi

Takaaki Kanazawa

Koichi Kasahara

Syuji Tateishi

Kei Masuda

Fumitada Murakami

Shizuo Sasaki

Hiroshi Okano

Shigemasa Hirooka

Yukio Kinugasa

Hiroki Ichinose

Masaru Kakinohana

Yoshiki Chujo

Eiji Iwasaki

Kenji Harima

Souichi Matsushita

Mikio Murachi

Jun Harada

Shinji Tsuji

Masahiko Sugiyama

Shigenori Sakurai

Kenji Ohkubo

Takao Naruoka

Tamotu Ogita

Shuichi Kubo

Masahiro Taki

Satomi Seto

Toshio Yamada

Motohisa Saiki

Keiji Itou

Tsuneyuki Tanizawa

Sinichi Takeshima

Sinya Hirota

Mariko Adachi

Kenichiro Shindo

Yoshiyuki Mandokoro

An exhaust gas control apparatus for an internal combustion engine, including a three-way catalyst, a NOstorage-reduction catalyst, a rich controlling mechanism performing control to make an air-fuel ratio of exhaust gas rich to reduce NOstored in the NOstorage-reduction catalyst, and a control performing control to ensure that a NOpurifying component is present in the NOstorage-reduction catalyst when reducing the NO.

Exhaust gas control apparatus and method for an internal combustion engine

An internal combustion engine control apparatus controls an internal combustion engine including: an exhaust passage including branch portions provided for the left and right banks and a common portion in which an exhaust gas purification device is provided; and a fuel supply system that supplies fuel to the respective engine cylinders. In the internal combustion engine, in order to recover the exhaust gas purification device, a bank control is executed in which the air-fuel ratio of the cylinders of the left bank is made rich while the air-fuel ratio of the cylinders of the right bank is made lean. The internal combustion engine is capable of running on alcohol-containing fuel and has an alcohol concentration sensor. The amount of unburned fuel to be supplied to the exhaust gas purification device during the bank control is adjusted based on the alcohol concentration in fuel.

Internal combustion engine control apparatus and method

An exhaust purification system for an internal combustion engine has a hydrogen concentration sensor () disposed upstream of a catalytic converter () in the engine exhaust system to detect a hydrogen concentration in the exhaust gas. An optimum combustion air-fuel ratio is then estimated based on the detected hydrogen concentration.

Exhaust purification system for internal combustion engine and control method of the exhaust purification system

A catalyst deterioration judgment device that can accurately perform a catalyst deterioration judgment by considering an oxygen density at downstream of an exhaust purification catalyst. The system reads outputs of an oxygen sensor and an ammonia sensor that are installed in downstream of an NSR catalyst when the catalyst is in an activate condition. When this read oxygen sensor output is equal to or more than a reference value and the ammonia sensor output is equal to or more than a reference value, it is estimated that ammonia oxidizing reaction does not occur under existence of oxygen in the NSR catalyst. In this case, the NSR catalyst is judged to be deteriorated.

Catalyst deterioration judgment device

An internal combustion engine exhaust gas purification apparatus purifies exhaust gas using a NOx storage-reduction catalyst unit and a NOx selective reduction catalyst unit. The NOx selective reduction catalyst unit is provided downstream of the NOx storage-reduction catalyst unit in an exhaust gas passage. An urea injecting mechanism, for example an injection valve, injects urea into the exhaust gas passage. An urea injection controller prohibits urea injection from the urea injecting mechanism if at least one of the temperatures of the NOx storage-reduction catalyst unit and the NOx selective reduction catalyst unit is equal to or lower than a reference temperature. As such, production of cyanic acid is minimized, and therefore leaks of cyanic acid from the NOx storage-reduction catalyst unit and/or the NOx selective reduction catalyst unit can be suppressed.

Internal combustion engine exhaust gas purification apparatus and method for controlling same

A NOocclusion and reduction catalystis arranged in an exhaust pathof an engineto purify NOin the exhaust gas. An electronic control unit (ECU)of the engine operates the engine in an operating mode in which the exhaust gas increases in temperature with the air-fuel ratio thereof kept rich each time a predetermined amount of SOis occluded in the catalyst, and executes the SOpoisoning restoration process for releasing SOfrom the catalyst. The ECU controls the engine air-fuel ratio in such a manner that the Hconcentration in the exhaust gas detected by the Hsensor arranged in the exhaust path upstream of the catalystis in a predetermined range. As a result, an appropriate amount of hydrogen is supplied to the catalystduring the SOpoisoning restoration process. Thus, an appropriate amount of hydrogen is supplied to the catalystduring the SOpoisoning restoration process, so that the HS generation is suppressed while at the same time executing the SOpoisoning restoration process efficiently.

Exhaust gas purification apparatus for internal combustion engine

A NOx occluding and reducing catalystis provided in an exhaust gas passage of an engine to occlude the NOx in the exhaust gas of a lean air-fuel ratio. The engine is provided with an injector for directly injecting the fuel into the combustion chamber, and the fuel fed by a fuel pump into a common rail with pressure is injected. The additive containing a sulfur-solidifying agent that forms a solid sulfate upon the reaction with sulfur in the fuel due to combustion, is injected into the common rail from a tank due to a pump, and is supplied into the combustion chamber through the injector together with the fuel. When the condition of the atmosphere of the NOx occluding and reducing catalyst is the one where the NOx in the exhaust gas is little absorbed, the ECU adjusts the discharge amount of the pump, and decreases the amount of the additive injected into the common rail or interrupts the injection. This decreases the consumption of the sulfur-solidifying agent.

Method of purifying exhaust gas of an internal combustion engine

A converter containing a NOx absorbing and reducing catalyst is disposed in the exhaust passage of an internal combustion engine. The upstream half portion (portion of the inlet side) of the substrate of the NOx absorbing and reducing catalyst in the converter carries the oxygen storage component that absorbs oxygen in the exhaust gas when the air-fuel ratio of the exhaust gas is lean and releases the absorbed oxygen when the air-fuel ratio of the exhaust gas flowing in is rich in addition to carrying the NOx absorbing and reducing catalyst. After NOx is absorbed by the NOx absorbing and reducing catalyst as a result of operating the engine at a lean air-fuel ratio, the engine is operated at a rich air-fuel ratio, so that NOx is released from the NOx absorbing and reducing catalyst and is purified by reduction. Here, oxygen is released from the oxygen storage component carried by the upstream half portion of the substrate and is reacted with the H and CO components in the exhaust gas, so that the temperature of the NOx absorbing and reducing catalyst is raised within short periods of time due to the heat of reaction. Therefore, the catalyst exhibits increased activity and the NOx absorbing and reducing catalyst exhibits improved NOx purification capability.

Exhaust gas purification device for an internal combustion engine

A NOx absorbent ( ) is disposed in an exhaust passage ( ) of an internal combustion engine ( ), and a control circuit ( ) is provided for controlling the amount of fuel injection into the engine ( ). The control circuit works to operate the engine at a rich air-fuel ratio by increasing the amount of fuel supply to the engine so that NOx absorbed by the NOx absorbent when the engine was last stopped is released in all amounts and is purified by reduction after the start of the engine until the engine is first operated at a lean air-fuel ratio. This prevents the release of unpurified NOx from the NOx absorbent ( ) at the start of the engine. The operation at a lean air-fuel ratio is assumed in a state where almost no NOx has been absorbed by the NOx absorbent ( ), enabling the absorbing capacity of the NOx absorbent to be utilized to the maximum degree.

Exhaust emission controlling apparatus of internal combustion engine

An exhaust purifying apparatus for an internal combustion engine includes a catalyst that purifies exhaust gas from the engine, a first passage that allows exhaust gas to flow from the engine to the catalyst, and a second passage that allows exhaust gas to flow from the engine to the catalyst. The first passage includes an accelerated cooling portion whose cross section is designed so that a relatively large quantity of heat is released from the exhaust gas in the first passage, and the second passage has a cross section designed so that a relatively small quantity of heat is released from the exhaust gas in the second passage. The apparatus further includes a flow amount controller that controls amounts of exhaust gas flowing through the first and second passages, such that the amount of exhaust gas flow through the first passage is made larger than that through the second passage when the temperature of exhaust gas emitted from the engine is to be lowered by a relatively large degree before reaching the catalyst, and such that the amount of exhaust gas flow through the second passage is made larger than that through the first passage when the temperature of exhaust gas emitted from the engine is to be lowered by a relatively small degree before reaching the catalyst.

Exhaust purifying apparatus and method for internal combustion engine

A control system for an internal combustion engine comprising a direct cylinder fuel injection valve for directly injecting the fuel into a cylinder of an internal combustion engine. The main fuel that burns in the cylinder is injected in the latter half of the compression stroke of the cylinder, and the secondary fuel which is the ineffective fuel that does not burn in the cylinder is injected in the latter half of the exhaust stroke, the main fuel and the secondary fuel being injected toward a cavity formed in the top surface of the piston. The main fuel that is injected is deflected by the cavity to form a charge of a combustible air-fuel ratio mixture around the spark plug. When the secondary fuel is injected, the exhaust valve is opening, and the fuel that is deflected is all discharged out of the cylinder through the exhaust port.

Control system for an internal combustion engine

An NOx-absorbing and reducing catalyst device is disposed in an exhaust passage of an engine. The NOx concentration in exhaust gas flowing out of the catalyst device is detected by an NOx sensor. Every time the NOx concentration detected by the NOx sensor increases to a predetermined value, an electronic control unit (ECU) of the engine reactivates the NOx-absorbing and reducing catalyst device by operating the engine at a rich air fuel ratio for a short time. The ECU also detects a deviation of the output of the NOx sensor on the basis of a reference value (corresponding to zero NOx concentration) and an output of the NOx sensor produced when the engine is being operated in a condition where the amount of NOx discharged from the engine is small, for example, a condition where the air-fuel ratio is on the lean side and the load is low (that is, in a condition where the NOx concentration in exhaust gas reaching the NOx sensor becomes substantially zero). Based on the detected deviation, the ECU corrects the output of the NOx sensor.

Emission control apparatus for internal combustion engine

An NOx occluding and reducing catalyst is disposed in an exhaust gas passage of an internal combustion engine that operates at a lean air-fuel ratio. When the engine is operating at a lean air-fuel ratio, the NOx occluding and reducing catalyst absorbs NOx in the exhaust gas. To release NOx, the engine is operated at a rich air-fuel ratio so that the exhaust gas flowing into the NOx occluding and reducing catalyst acquires a rich air-fuel ratio. While the engine is operated in a region of moderate lean air-fuel ratios of from the stoichiometric air-fuel ratio to an air-fuel ratio of about 20 at the time when the engine operating air-fuel ratio is changing from a lean air-fuel ratio operation to a rich air-fuel ratio operation, an electronic control unit (ECU) of the engine injects secondary fuel, that does not contribute to combustion, into the cylinders of the engine through the direct cylinder fuel injection valves in the expansion stroke or the exhaust stroke of the cylinders, so that the exhaust gas flowing into the NOx occluding and reducing catalyst acquires a rich air-fuel ratio. This prevents unpurified NOx from flowing out of the NOx occluding and reducing catalyst at the time when the engine operating air-fuel ratio is changed.

A control system for an internal combustion engine including a direct cylinder fuel injection valve for directly injecting the fuel into a cylinder of an internal combustion engine. The main fuel that burns in the cylinder is injected in the latter half of the compression stroke of the cylinder, and the secondary fuel which is the ineffective fuel that does not burn in the cylinder is injected in the latter half of the exhaust stroke main fuel and the secondary fuel air-fuel ratio mixture around the spark plug. When the secondary fuel is injected, the exhaust valve is opening, and the fuel that is deflected is all discharged out of the cylinder through the exhaust port. Therefore, the ineffective fuel supplied by the secondary fuel injection does not remain in the cylinder, and the output torque does not change in the combustion of the next cycle.

A method for purifying an exhaust gas by simultaneously removing carbon monoxide, hydrocarbons, and nitrogen oxides contained in the exhaust gas, comprising bringing the oxygen rich exhaust gas into contact with an exhaust gas purifying catalyst comprised of at least one noble metal selected from the group consisting of platinum and palladium, at least one alkaline earth metal selected from the group consisting of barium, magnesium, calcium, and strontium, and at least one alkali metal selected from the group consisting of iron, nickel, and cobalt, supported on a carrier composed of a porous substance.

Method for purifying exhaust gas

Growing community of inventors

Shizuoka, Japan

Kenji Katoh