Toyota Jidosha Kabushiki Kaisha

Nippon Soken, Inc.

Toyota Jidosha Kogyo Kabushiki Kaisha

Michihiro Ohashi

Hiroki Matsuoka

Eizi Tanaka

Hiroshi Mochizuki

Hiroshi Sawada

Hiroshi Kanai

Yukihiro Sonoda

Kouichi Osawa

Kouichi Hoshi

Tooru Kosuda

Toru Hanafusa

Akira Nishimatsu

Seikou Abe

Hisasi Kawai

Toshihiko Igashira

Hidehiro Oba

Norihisa Nakagawa

Takaaki Itou

Shinichi Matsumoto

Yukio Kinugasa

Toshifumi Takaoka

Yasuhiro Takeuchi

Koji Yokota

Masaaki Takizawa

Ken Nomura

Kouhei Igarashi

Minoru Iwata

Katsushi Anzai

Noboru Matsubara

Tadahide Toda

Hiromi Katou

Sinji Kato

Eiji Tanaka

Kiyoshi Asada

Mitiaki Ujihashi

Norio Nakamura

Ryouichi Harada

A device for determining the abnormal degree of deterioration of catalyst of a catalytic converter arranged in an internal combustion engine exhaust system is disclosed. The device comprises ability value grasping means for grasping an ability value in relation with a current purification ability of the catalyst and varying amount grasping means for grasping a varying amount of the ability value grasped by the ability value grasping means. It is determined that the degree of deterioration of the catalyst is abnormal when the varying amount grasped by the varying amount grasping means is smaller than a predetermined value.

Device for determining an abnormal degree of deterioration of a catalyst

A device for determining the abnormal degree of deterioration of catalyst of a catalytic converter arranged in an internal combustion engine exhaust system is disclosed. The device comprises a purification ability grasping unit for grasping a current purification ability of the catalyst and a temperature sensor for grasping a current temperature of the catalyst. Therefore, a threshold of the purification ability which corresponds to the abnormal degree of deterioration of the catalyst is determined in accordance with the current temperature of the catalyst. An appraisal value is determined in accordance with a difference between the threshold and the current purification ability. It is determined that the degree of deterioration of the catalyst is abnormal when the integration value of the appraisal value exceeds a predetermined value.

Device for determining the abnormal degree of deterioration of a catalyst

A device for determining the abnormal degree of deterioration of a catalyst of a catalytic converter arranged in an internal combustion engine exhaust system is disclosed. The device includes first and second air-fuel ratio sensors located upstream and downstream of the catalyst. The device determines a first purification ability based on readings of the sensors during a warmup stage of the catalyst, and a second purification ability after the warmup is completed. An overall purification ability of the catalyst is determined by combining the purification ability of the catalyst during warmup and the purification ability of the catalyst after warmup, where the weight of the purification ability during warmup is less than the purification ability after warmup in the overall purification ability. If the overall purification ability of the catalyst is less than a certain amount, then the device determines that the catalyst has deteriorated.

The method for purifying combustion exhaust gas according to the present invention utilizes a NH.sub.3 decomposing catalyst. The NH.sub.3 decomposing catalyst in the present invention is capable of converting substantially all of the NH.sub.3 in the combustion exhaust gas to N.sub.2 when the air-fuel ratio of the exhaust gas is lean and the temperature of the catalyst is within a predetermined optimum temperature range. Further, when the exhaust gas contains NO.sub.x in addition to NH.sub.3, the NH.sub.3 decomposing catalyst is capable of reducing the NO.sub.x in the optimum temperature range even though the air-fuel ratio of the exhaust gas is lean. In the present invention, the conditions of the exhaust gas containing NO.sub.x are adjusted before it is fed to the NH.sub.3 decomposing catalyst in such a manner that the temperature of the exhaust gas is within the optimum temperature range and the air-fuel ratio of the exhaust gas is lean. Further, NH.sub.3 is added to the exhaust gas before it is fed to the NH.sub.3 decomposing catalyst. Therefore, a lean air-fuel ratio exhaust gas, at a temperature within the optimum temperature range, which contains both the NO.sub.x and NH.sub.3 is fed to the NH.sub.3 decomposing catalyst, and the NO.sub.x, as well as the NH.sub.3, in the exhaust gas is completely resolved by the NH.sub.3 decomposing catalyst.

Method for purifying combustion exhaust gas

A device for determining the excessive degree of deterioration of catalyst of a catalytic converter arranged in an internal combustion engine exhaust system is disclosed. The device comprises a purification ability determining unit for determining a current purification ability of the catalyst and a temperature sensor for determining a current temperature of the catalyst. Therefore, a threshold of the purification ability which corresponds to the excessive degree of deterioration of the catalyst is determined in accordance with the current temperature of the catalyst. An appraisal value is determined in accordance with a difference between the threshold and the current purification ability. It is determined that the degree of deterioration of the catalyst is excessive when the integration value of the appraisal value exceeds a predetermined value.

A fuel supply control system for an engine comprises a fuel injector for feeding fuel into the engine, a canister for temporarily storing fuel vapor, and an air-fuel ratio sensor for sensing an air-fuel ratio of the engine. The canister is connected to an intake passage downstream of a throttle valve to purge a purge gas, that is, air containing fuel vapor, into the intake passage. An amount of fuel to be injected from the fuel injector is corrected in accordance with output a signals of the air-fuel ratio sensor to make the air-fuel ratio equal to a target air-fuel ratio. An initial value of a fuel vapor concentration coefficient, which represents a concentration of fuel vapor in air fed into the engine, is calculated in accordance with a deviation caused when the purging operation starts. A decrement of the fuel vapor concentration coefficient caused when the purge gas is purged by a predetermined amount is calculated using a relationship between the decrement and the fuel vapor concentration coefficient, which relationship is prepared in advance. The fuel vapor concentration coefficient is further corrected by subtracting the decrement from the initial value whenever the purge gas is purged by the predetermined amount. The amount of fuel is reduced in accordance with the fuel vapor concentration coefficient.

Fuel supply control system for an engine

An idling speed control device normally controlling the idling speed of the engine so that it becomes equal to a desired idling speed. At the time of acceleration, the lean time and the rich time of the air-fuel mixture are calculated during the lean-rich discriminating time, which is basically equal to a time of an occurrence of the lean time and the rich time when the air-fuel ratio is maintained at the stoichiometric air-fuel ratio at the time of acceleration. If the lean time becomes considerably longer than the rich time when the engine is started, the idling speed is increased.

Idling speed control device of an engine

A fuel injection control device in which the amount of fuel injected by the fuel injector is increased at the time of acceleration. Namely, at the time of acceleration, the lean time and the rich time of the air-fuel mixture are calculated during the lean-rich discriminating time, which is basically equal to a time of an occurence of the lean time and the rich time when the air-fuel ratio is maintained at the stoichiometric air-fuel ratio at the time of acceleration. When the lean time becomes considerably longer than the rich time, the amount of fuel injected by the fuel injector is further increased.

Fuel injection control device of an engine

A fuel injection control device in which the supply of fuel into the engine cylinder is stopped at the time of deceleration, and a rich time of the air-fuel mixture is calculated when the supply of fuel is stopped. If the rich time becomes relatively long, the accelerating increasing rate of the amount of fuel is increased, and if the rich time becomes relatively short, the accelerating increasing rate of the amount of fuel is reduced.

A fuel injection control device in which it is determined whether the air-fuel mixture is lean or rich at a predetermined crankangle during a lean-rich discriminating time at the time of acceleration. The lean-rich discriminating time is shortened as the degree of the acceleration becomes larger, and the times of being lean and the times of being rich within the lean-rich discriminating time are calculated. When the times of being lean are larger than the times of being rich, and the difference therebetween is larger than a predetermined value, the accelerating increasing rate of the amount of fuel fed into the engine cylinder is increased.

An electronic control device in an internal combustion engine with an EGR apparatus for calculating a predetermined control variable such as a fuel injection time period or an ignition timing, and correcting same to exclude a component stemming from EGR gas in the intake air. The device comprises a first unit for calculating a fundamental value of the fuel injection time period (TP), a second unit for converting the detected intake pressure under the detected atmospheric pressure into a converted intake pressure under the standard atmospheric pressure in response to the detected atmospheric pressure and a third unit for calculating a correcting value (TPE) from data including information regarding the EGR gas under the standard atmospheric pressure and stored as a function of the converted intake pressure (PMT). In this device, the fundamental value can be corrected by subtracting the correcting value from the fundamental value in the case of the fuel injection time period.

Electronic control device for internal combustion engine with EGR

A device for atomizing the fuel for an internal-combustion engine comprising a fuel pump, an electromagnetic fuel-injection valve connected to said fuel pump, an air-injection port adjoining the injection port of said electromagnetic fuel-injection valve, an electromagnetic air flow-controlling valve connected to said air-injection port, and an air pump for feeding air to said air flow-controlling valve, wherein said air flow-controlling valve is controlled in such a manner that the injection of air from said air-injection port takes place simultaneously with the injection of fuel from said fuel-injection valve, whereby the air pump and the driving circuit thereof are of a comparatively small size and the amount of power necessary for driving the air pump is of comparatively small.

Device for atomizing the fuel for an internal-combustion engine

A hydraulic valve lift device for transmitting the motion of a cam to a push rod of an intake or exhaust valve of an engine, including a housing, a lifter slidably engaged by the housing and provided therein with an oil pressure chamber adapted to receive an oil, and a plunger provided with a flange portion and slidable in relation to the lifter. The flange portion of the plunger and cylindrical bore of the housing cooperate with each other to define therebetween a braking chamber into which oil is introduced. The device has a slit through which the oil in the braking chamber is relieved to the outside. The arrangement is such that the rate of oil relieved through the braking chamber is reduced as the plunger is lowered. The device further includes a relief valve for maintaining the pressure in the braking chamber below a predetermined pressure level.

Hydraulic valve lift device

A fuel injection system for an internal combustion engine has an air sensor for metering the intake air flow into the engine and a fuel metering and distributing device hydraulically coupled together. The device includes a plunger rotated by the engine to distribute fuel to respective fuel injectors and axially moved in response to variation in the intake air flow rate to meter the fuel. The axial displacement of the plunger is determined by two opposing hydraulic pressures acting on the opposite ends of the plunger, one of which is varied in accordance with the engine intake air flow rate as detected by the air sensor while the other hydraulic pressure is changed in accordance with the axial displacement of the plunger. Since no mechanical linkage is required between the air sensor and the fuel metering and distributing device, the system can easily be installed in a limited space and, in addition, assure an improvement in the accuracy of the fuel control.

Fuel injection system for an internal combustion engine

A supercharged internal combustion engine is provided with a turbo supercharger mounted on an intake pipe and driven by engine exhaust gases to produce a pressurized intake air to be fed into the engine. A bypass intake pipe branches out of the intake pipe upstream of the supercharger and merges into the intake pipe at a point downstream of the supercharger. A first valve member is disposed in the intake pipe adjacent to the merging point to control the communication between the intake pipe and the bypass intake pipe and the communication between the upstream part of the intake pipe and the downstream part of the intake pipe. A first and second air release ports are formed in the intake pipe, one of which is disposed between the supercharger and the merging point and the other is disposed downstream of the merging point. Second and third valve members are provided to open and close the first and second air release ports, respectively. The first and second valve members are pneumatically actuated in accordance with the variation in the engine intake manifold pressure, whereas the third valve member is moved to its open position when the pressure in the intake pipe downstream of the merging point exceeds a predetermined level.

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Mishima, Japan

Michihiro Ohashi