Toyota Jidosha Kabushiki Kaisha

Makoto Tomimatsu

Takahiko Fujiwara

Koichi Hoshi

Ryota Onoe

Junichi Suzuki

Shogo Suda

Mamoru Yoshioka

Koichi Kimura

Yuuichi Katou

Nobuhiko Koga

Shuntaro Okazaki

Kenji Sakurai

Kazuhiro Sugimoto

Yoshihisa Shinoda

Daisuke Ishii

Yuuichi Kato

Yoshihiko Suzuki

Takuya Ookubo

Makoto Fukumoto

There is provided a controller configured to carry out at least one of first control and second control, in cases where the internal combustion engine is in a predetermined operating state in which the EGR valve is caused to be fully closed, the first control being that an amount of fuel to be injected into an intake passage is made smaller, and an amount of fuel to be injected into a cylinder is made larger, in the presence of the abnormality of the EGR valve being not fully closed than in the absence of the abnormality, and the second control being that a pressure of fuel to be injected into the cylinder is made higher in the presence of the abnormality of the EGR valve being not fully closed than in the absence of the abnormality.

Control system for an internal combustion engine

An air-fuel ratio control controls an air-fuel ratio (air-fuel ratio of an engine) of a mixture supplied to the engine, based on an output value of the downstream-side air-fuel ratio sensor disposed downstream of a catalyst. That is, the air-fuel ratio control apparatus sets the air-fuel ratio of the engine at a rich air-fuel ratio when the output Voxs is smaller than a reference value VREF (when a rich request is occurring). The air-fuel ratio control apparatus sets the air-fuel ratio of the engine at a lean air-fuel ratio when the output Voxs is larger than a reference value VREF (when a lean request is occurring). The air-fuel ratio control apparatus makes the target value VREF gradually come closer to a reference value VF (stoichiometric air-fuel ratio corresponding value) from a certain value, when the output value Voxs deviates greatly from the reference value Vf (points P-P).

Air-fuel ratio control apparatus for an internal combustion engine

An object of this invention is to provide an atmosphere-cleaning device for vehicles that is capable of restoring the function of an ozone purifying body carried by a vehicle component. Mud, dust, snow-melting agents as well as SOx and NOx are scattered into the atmosphere as a result of being swirled up by a preceding vehicle or due to weather and climate conditions. When such extraneous substances adhere or the like to an ozone purifying body, the purification sites thereof are clogged and the ozone purification function deteriorates. Therefore, when a predetermined removal implementation condition is established, control is executed to inject cleaning liquid from an injector to enhance the fluidity of the extraneous substances and wash the extraneous substances away. The function of the ozone purifying body can thereby be restored.

Atmosphere-cleaning device for vehicles

An internal combustion engine includes fuel injection valves and an ECU. In the internal combustion unit, predetermined injection is performed when the bed temperature of a catalyst is lower that a predetermined temperature. In the predetermined injection, fuel is injected from a first fuel injection valve, from among the fuel injection valves, within the valve opening period of an intake valve, and fuel is injected from a second fuel injection valve, from among the fuel injection valves, within the valve opening period of an exhaust valve. In the internal combustion engine, a first injection amount is specifically injected from the first fuel injection valve in the predetermined injection.

Internal combustion engine

An air-fuel ratio control apparatus for an internal combustion engine of the present invention determines whether or not a lean request has occurred, based on a comparison between a value correlating with an output value of the downstream air-fuel ratio sensor disposed downstream of the catalyst (downstream air-fuel ratio sensor output correlating value) and a predetermined lean request determining value, and determines whether or not a rich request has occurred, based on a comparison between the downstream air-fuel ratio sensor output correlating value and a predetermined rich request determining value. Further, the air-fuel ratio control apparatus calculates a total amount of oxygen (released oxygen amount) released from the catalyst in the rich request occurring period, and calculates an integrated value (present stored oxygen amount) of oxygen stored in the catalyst after a start of the lean request occurring period which follows the rich request occurring period. The apparatus changes the rich request determining value in such a manner that a point in time at which it is determined that the rich request has occurred comes much earlier as the present stored oxygen amount comes closer to the released oxygen amount.

An air-fuel ratio control apparatus for an internal combustion engine according to an embodiment of the invention (the present control apparatus) sets a target air-fuel ratio to a target rich air-fuel ratio when it is determined on the basis of the output value Voxs of a downstream air-fuel ratio sensorthat the oxygen adsorption amount of a catalysttends to be excessive, and sets the target air-fuel ratio to a target lean air-fuel ratio when it is determined on the basis of the output value Voxs that the oxygen adsorption amount of the catalysttends to be insufficient. Further, the present control apparatus determines whether or not an operation state in which a large amount of nitrogen oxide flows into the catalystis reached on the basis of 'whether a predetermined condition is fulfilled', and makes the target rich air-fuel ratio obtained when the predetermined condition is fulfilled less than the target rich air-fuel ratio obtained when the predetermined condition is not fulfilled. As a result, the concentration of a reducing agent inside the catalystcan be increased before a large amount of NOx flows into the catalyst. Therefore, when a large amount of NOx flows into the catalyst, most of the NOx can be eliminated.

Air-fuel ratio control device for internal combustion engine

An embodiment (control apparatus) of an air-fuel ratio control apparatus according to the present invention determines, based on an output value Voxs of a downstream air-fuel ratio sensordisposed at a position downstream of a three-way catalyst, which air-fuel request is occurring, a rich request or a lean request. The control apparatus sets an air-fuel ratio of each cylinder (cylinder-by-cylinder air-fuel ratio) to a rich air-fuel ratio when the rich request is occurring, and sets the cylinder-by-cylinder air-fuel ratio to a lean air-fuel ratio when the lean request is occurring. The control apparatus has a cylinder-by-cylinder air-fuel ratio of a specific cylinder different from a cylinder-by-cylinder air-fuel ratio of the other cylinder so as to obtain a fluctuation period correlated value indicative of a fluctuation of the output value Voxs of the downstream air-fuel ratio sensor, and determines an influence/impact degree on the output value of the downstream air-fuel ratio sensor of an exhaust gas discharged from each of a plurality of cylinders, based on the fluctuation period correlated value. Further, the control apparatus controls the air-fuel ratio of each cylinder in accordance with the influence degree.

An air-fuel ratio control apparatus of the present invention comprises an inverse direction spike introducing section and an inverse direction spike interval setting section. The inverse direction spike introducing section introduces, while an air-fuel ratio correction required by an output of a downstream air-fuel ratio sensor is being carried out, an inverse direction spike which is an air-fuel ratio spike to temporarily change an air-fuel ratio of an exhaust gas toward a direction opposite to a direction of the air-fuel ratio correction with respect to a target control air-fuel ratio. The inverse direction spike interval setting section sets, based on an operating state of an internal combustion engine system, an inverse direction spike interval which is an interval between two of the inverse direction spikes next to each other in time.

Air-fuel ratio control apparatus

An air-fuel ratio control apparatus of the present invention includes a determination section and a reverse direction correction introducing section. The determination section determines whether or not an output of the downstream air-fuel ratio sensor falls within a predetermined range whose center corresponds to a target value corresponding to the stoichiometric air-fuel ratio. When the output of the downstream air-fuel ratio sensor falls within the predetermined range, the reverse direction correction introducing section temporarily introduces, to an air-fuel ratio correction in a direction requested by the output, an air-fuel ratio correction in a direction opposite to the requested direction.

An internal combustion engine is provided with a fuel injector which injects fuel into an intake port and exhaust variable valve timing mechanism which changes a valve timing of an exhaust valve. A control device executes early exhaust valve closing control which advances a closing timing of an exhaust valve when conditions for executing early exhaust valve closing control stand. The control device detects an output torque output by an engine body. At the time of deceleration of the engine, even when the condition for executing early exhaust valve closing control stands, execution of early exhaust valve closing control is prohibited when it is predicted that the output torque will become smaller than the limit torque. Thus, due to execution of the early exhaust valve closing control, a large torque fluctuation is prevented from occurring at the time of deceleration of the engine.

Control device of internal combustion engine

An exhaust valve early-closure control brings about blowback of exhaust gas into an intake system. However, if the exhaust valve early-closure control is executed, for example, during a first idle operation immediately following the startup of the engine, or the like, the amount of blowback exhaust gas becomes excessively large. Therefore, when the post-startup increase amount has decreased to or below a lower-limit criterion value, the ECU prohibits the exhaust valve early-closure control, and changes the control to a usual valve timing control. As a result, during a period during which the combustion state has a stability margin and the amount of emission of HCs and the like is large, the exhaust emission quality can be bettered by the exhaust valve early-closure control. Besides, when the post-startup increase amount has decreased, the combustion state can be stabilized by prohibiting the exhaust valve early-closure control.

Control device for internal combustion engine

The oil pressure for a hydraulic actuator () of a variable valve train () is controlled in accordance with a duty value of a control signal for a hydraulic control valve (). When predetermined inching control execution conditions are established, inching control in which the duty value is varied in a pulsed manner between a retention duty value, which retains an operation of the hydraulic actuator, and a forced drive duty value, which forcibly drives the hydraulic actuator, is exercised instead of duty value feedback control in which the duty value is calculated in accordance with the deviation between an actual valve opening characteristic and a target valve opening characteristic. If the oil temperature is lower than a predetermined temperature, inching control is exercised to ensure that the first pulse width generated after the start of inching control is wider than normal.

Variable valve train control device

A first overlap amount that is an overlap amount of overlap between an intake valve opening timing and an exhaust valve opening timing, is calculated based on rotation speed of an internal combustion engine, load on the engine, and temperature of a working fluid. A second overlap amount that is the overlap amount that is set so that the relative rotation phase of at least one of the intake-side camshaft and the exhaust-side camshaft relative to the rotation phase of the crankshaft is fixed when the engine stops, is calculated based on the temperature of the working fluid. The overlap amount is set to equal to the second overlap amount, if the first overlap amount is larger than the second overlap amount. The overlap amount is set to equal to the first overlap amount, if the first overlap amount is less than or equal to the second overlap amount.

Variable valve apparatus

An internal combustion engine, including an air/fuel ratio sensor in an exhaust passage detecting an air/fuel ratio in a heated state, implements a technique improving emission at a starting time, by eliminating splash of water droplets early in the exhaust passage at the starting time to advance the heating starting timing of the air/fuel ratio sensor. At the starting time, opening/closing timing of a valve is advanced from a reference opening/closing timing or the reference of the opening/closing timing of the exhaust valve after the warming-up was ended, which continues until the wall temperature of the exhaust passage near the air/fuel ratio sensor becomes equal to or higher than a water droplet disappearing temperature, at which water droplets disappear. Then, change of the opening/closing timing of the exhaust valve responding to the running state by a variable valve mechanism is started.

An internal combustion engine control apparatus executes an exhaust-valve-early-closing valve timing control in which an exhaust valve is closed before the intake stroke top dead center. The fuel injection timing mode is normally set to an intake-stroke non-synchronized fuel injection mode. However, if the internal combustion engine is idling and the combustion gas temperature is relatively high, the fuel injection timing mode is switched from the intake-stroke non-synchronized fuel injection mode to an intake-stroke synchronized fuel injection mode.

Growing community of inventors

Susono, Japan

Makoto Tomimatsu