Denso Corporation

Kazuo Kojima

Hiroshi Haraguchi

Shinichiro Okugawa

Takahiro Ono

Youhei Morimoto

Masumi Kinugawa

Shigeto Yahata

Jun Kawamura

Shoichi Yokoyama

Jyun Kawamura

Tsutomu Soga

Shinichirou Okugawa

Atsushi Takano

In an engine exhaust gas purification apparatus incorporating a LNT (lean NOx trap), during a NOx catalyst regeneration procedure for deoxidizing and removing accumulated sulfur from the LNT by producing a fuel-rich atmosphere in the exhaust system, the point at which to terminate the regeneration procedure is judged based on a difference between values of A/F ratio measured by sensors located respectively upstream and downstream from the LNT, with the regeneration being terminated when the difference falls below a predetermined threshold value.

Engine exhaust gas purification apparatus enabling accurate judgement of appropriate time for terminating NOx catalyst regeneration procedure

An exhaust gas purification device of an internal combustion engine having a NOx catalyst provided to an exhaust passage for occluding NOx in a lean atmosphere and for reducing the occluded NOx in a rich atmosphere has an exhaust gas recirculation passage for recirculating the exhaust gas from the exhaust passage to an intake passage, an exhaust gas recirculation valve provided in the exhaust gas recirculation passage, a rich combustion control section for performing rich combustion in the internal combustion engine, and an exhaust gas recirculation valve control section for controlling an opening degree of the exhaust gas recirculation valve to conform a pressure value in the intake passage to a predetermined pressure value while the rich combustion control section performs the rich combustion.

Exhaust gas purification device of internal combustion engine

The present invention provides, as one aspect, an exhaust gas purifying apparatus for an internal combustion engine including a setting unit that sets commanded values of an amount and a period of injection from an additive fuel injector, an adding controlling unit that injects fuel from the additive fuel injector in accordance with the commanded values, a determining unit that determines whether a high-accuracy measurement state has been entered in which a difference between measurement values of first and second air-to-fuel ratio sensors is within a predetermined range, and a calculating unit that calculates, when the high-accuracy measurement state has been entered, a deviation between the commanded value and a true value of the amount of injection by the adding controlling unit as a correction value, from at least one of the measurement values of the first and second air-to-fuel ratio sensors.

Exhaust gas purifying apparatus for internal combustion engine

A control device has a throttle valve and fuel injection valves supplying air and fuel to an internal combustion engine, a meter detecting an actual quantity of the air supplied to the engine, a sensor detecting an actual oxygen concentration of an exhaust gas outputted from an exhaust system of the engine, and an ECU controlling the valves. To regenerate an exhaust emission purifier disposed in the exhaust system at a target temperature appropriate to the regeneration of the purifier, the ECU determines a target oxygen concentration corresponding to a target air-fuel ratio and a basic air quantity according to a torque required of the engine and controls the valves according to the actual air quantity and the actual oxygen concentration to supply a basic quantity of fuel and the basic quantity of air to the engine at the target air-fuel ratio.

Control device for internal combustion engine

During lean combustion, an ECU as a control device for a diesel engine calculates a ratio between a target A/F value and a detected A/F value detected by a A/F sensor, wherein the target A/F value is a ratio between a target air volume and a target injection amount in order to obtain a request torque. The ECU calculates the air volume after compensation during rich combustion by multiplying the target air volume with the compensation gain value. The ECU instructs an air intake throttle valve and an EGR valve to regulate those opening degrees according to the calculation result in order to decrease a torque difference between the lean combustion and the rich combustion.

An exhaust gas purification device senses an air-fuel ratio of exhaust gas flowing into a catalyst and performs rich purge control for supplying fuel for reduction to the catalyst. The device calculates a total reducing agent amount consumed for the reduction during the rich purge control based on the air-fuel ratio and a fresh air amount as of the rich purge control. The device sets a specified air-fuel ratio state for controlling the air-fuel ratio in a certain range enabling more precise measurement of the air-fuel ratio than in the rich purge control. The device corrects the total reducing agent amount based on a difference between an injection amount command value as of the rich purge control and the injection amount command value in the specified air-fuel ratio state and the air-fuel ratio sensed in the specified air-fuel ratio state.

Exhaust gas purification device for internal combustion engine

A control apparatus for a multi-cylinder internal combustion engine includes pressure sensors used for acquiring combustion chamber pressure data for each engine cylinder, during each of a series of selection intervals respectively corresponding to that cylinder, with each selection interval corresponding to a specific angular displacement of the crankshaft and having a timing determined with respect to a reference piston position in the corresponding cylinder. The timing of the selection intervals is adjusted in accordance with current conditions of the engine, such as a fuel injection mode, to be appropriate for monitoring combustion conditions in the cylinders.

Apparatus for controlling timings of intervals in which combustion chamber pressure data are acquired from output signals of cylinder pressure sensors of multi-cylinder internal combustion engine

An engine torque control apparatus is applied to an engine control system comprising an engine for rotating an output shaft by using torque generated through combustion in cylinders. In the apparatus, exhaust gas passing through an exhaust passage of the engine is partially recirculated into an intake passage of the engine. Also, variable control is conducted in the apparatus, when an air-fuel ratio indicating a proportion between air and fuel supplied into the cylinders of the engine is changed to a leaner air-fuel ratio, so that torque parameters for increasing/decreasing output torque of the engine can be variably controlled. As a result, torque fluctuation associated with a temporarily changing recirculated uncombusted fuel quantity can be cancelled in a manner suitable for the temporarily changing recirculated uncombusted fuel quantity, at least during a predetermined period immediately after timing for changing the air-fuel ratio.

Engine torque control apparatus and method for adjusting engine torque control apparatus

An engine control system and an engine control method are disclosed wherein a combustible component quantity of intake air, reflecting combustible components in a crankcase of an engine, is calculated on the basis of a deviation between basic injection quantity for a target rotational speed to be attained and an actual injection quantity during operation to perform idling stabilizing control. A ratio of the combustible components mixed to engine oil is calculated on the basis of the combustible component quantity of intake air and a temperature of engine oil. During a status of the engine with a given temperature of engine oil and the mixing ratio of the combustible components in engine oil, a fuel injection affect eliminating operation is executed.

Engine control system and engine control method

In order to restrict an over-temperature-rising of a diesel particulate filter (DPF), an electronic control unit (ECU) computes a flow rate of the exhaust gas flowing through the DPF so that temperature of the DPF is kept at a temperature in which the DPF can be regenerated. By adjusting a position of a throttle valve, a fresh air flow rate is adjusted so that the flow rate of the exhaust gas flowing through the DPF is equal to a target flow rate of the exhaust gas.

Exhaust gas filtering system for internal combustion engine

In an engine, when it is determined that catalyst, which is held on a filter substrate of a particulate filter, is not in an active state, an ECU executes a fuel injection for mainly obtaining an engine power near a top dead center of a crank. Then, the ECU executes a subsequent fuel injection after lapse of a sufficient injection interval, which does not cause misfiring, to increase the temperature of exhaust gas outputted from the engine. In this way, the temperature of the filter is rapidly increased.

Exhaust gas cleaning device for internal combustion engine

An electronic control unit of an internal combustion engine calculates a basic post-injection quantity of temperature increasing means if a deposition quantity of particulate matters deposited on a diesel particulate filter (DPF) exceeds a predetermined value. Then, a final post-injection quantity is calculated by correcting the basic post-injection quantity based on a temperature correction value, which is calculated by multiplying a deviation between DPF upstream exhaust gas temperature and target temperature and past temperature correction values by feedback gains. The feedback gains are switched in accordance with a delay in an exhaust gas temperature change in a present operating state, based on an intake air quantity sensed by an air flow meter. Thus, response can be improved, while maintaining stability.

Exhaust gas purification system of internal combustion engine

An ECU controls an opening degree of an EGR gas switch valve based on a temperature of intake air and a load state of an engine in such a manner that a temperature of exhaust gas becomes a suitable temperature, which is suitable for regeneration of a particulate filter arranged in an exhaust gas passage. In this way, cooled EGR gas, which passes a main passage, and hot EGR gas, which passes a bypass passage, are appropriately mixed. In a case, where reliability of an EGR valve cannot be maintained, EGR cut is performed.

Exhaust gas purifying apparatus

An exhaust cleaning device of an internal combustion engine includes a particulate filter disposed in an exhaust duct of the internal combustion engine. A regeneration control increases the temperature of the particulate filter to approximately a predetermined target temperature but the amount of the temperature increase controllably corrected by the regeneration control.

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Nagoya, Japan

Kazuo Kojima