Toyota Jidosha Kabushiki Kaisha

Koji Umezawa

Makoto Yamazaki

Yuto Ikeda

Kinji Morihiro

Katsuhiro Ito

Shinya Kondo

Yusuke Kawamura

Satoshi Ido

A controller and a control method for an internal combustion engine are provided. The internal combustion engine uses hydrogen as fuel. A base value of a fuel injection amount is calculated based on a requested torque. A smaller one of an upper limit value of the fuel injection amount and the base value is set as a target value. The upper limit value corresponds to an engine load factor. A NOx concentration difference is a difference between a NOx concentration in exhaust gas and a reference value for the NOx concentration. When the NOx concentration difference is greater than or equal to a threshold value, a relationship between the engine load factor and the upper limit value is corrected such that the upper limit value decreases.

Controller for internal combustion engine and method for controlling internal combustion engine

A controller for a hydrogen engine controls a hydrogen engine including a selective catalytic reduction (SCR) device installed in an exhaust passage and a urea addition valve that adds urea to exhaust gas flowing through a portion of the exhaust passage upstream of the SCR device. Processing circuitry of the controller executes a reduction process that causes a urea addition amount of the urea addition valve to be smaller when a urea deposition amount of the SCR device is greater than or equal to a prescribed value than when the urea deposition amount is less than the prescribed value. The processing circuitry executes a lean-burn limiting process that sets an air-fuel ratio of an air-fuel mixture to be burned in the hydrogen engine to a value less than or equal to a prescribed lean-burn limiting value while the reduction process is reducing the urea addition amount.

Controller for hydrogen engine

An internal combustion engine includes a fuel injection valve configured to inject hydrogen gas into the cylinder, a selective catalytic reduction catalyst located in an exhaust passage and configured to remove NOx, a urea water injection valve configured to inject urea water into the catalyst, a tank that stores urea water injected by the urea water injection valve, and a remaining amount detection sensor configured to detect a remaining amount of urea water stored in the tank. A controller for the internal combustion engine is configured to execute a restriction process that controls, when the remaining amount is less than a set value, an injection amount of hydrogen gas by the fuel injection valve such that an air excess ratio in the cylinder becomes greater than or equal to a specified excess ratio that is greater than 1.

Controller for internal combustion engine

A first condition is set to such a condition of a fuel injection amount of a fuel injection valve and an opening degree of a throttle valve that an air excess ratio in a cylinder becomes greater than or equal to a prescribed value set as a value greater than 1.2 while satisfying a target output of an internal combustion engine. A second condition is set to such a condition of the fuel injection amount and the opening degree of the throttle valve that the air excess ratio in the cylinder becomes 1 or less while satisfying the target output of the internal combustion engine. A controller of the internal combustion engine is configured to obtain the first and second operating conditions that correspond to the target output, and select one of the operating conditions in accordance with the operating situation of the internal combustion engine.

Controller and control method for internal combustion engine

A decrease in purification performance of a system as a whole is suppressed in cases where catalysts are arranged in an upstream side portion and in a downstream side portion of an exhaust passage in an internal combustion engine. A first catalyst, a sensor and a second catalyst are sequentially arranged in the exhaust passage of the internal combustion engine, wherein a switch is made between lean control and rich control in such a manner that an amount of increase or decrease in a storage amount of oxygen falls within a predetermined range, and in cases where the rich control is carried out after performing a predetermined number of times of rich control, the rich control is continued until an air fuel ratio detected by the sensor becomes equal to or less than a rich determination threshold value which is smaller than a stoichiometric air fuel ratio.

Exhaust gas purification apparatus for internal combustion engine

An exhaust purification system of the internal combustion engine comprises: an upstream side catalystarranged in an exhaust passage, a downstream side catalystarranged at a downstream side of the upstream side catalyst, an air-fuel ratio sensordetecting an air-fuel ratio of outflowing exhaust gas flowing out from the upstream side catalyst, an air-fuel ratio control partcontrolling an air-fuel ratio of inflowing exhaust gas flowing into the upstream side catalyst to a target air-fuel ratio, and a temperature calculating partcalculating a temperature of the downstream side catalyst. The air-fuel ratio control part switches the first control to the second control when a temperature of the downstream side catalyst calculated by the temperature calculating part rises to a reference temperature which is equal to or higher than an activation temperature of the downstream side catalyst.

Exhaust purification system of internal combustion engine

A secondary air supply system includes an electric air pump that supplies secondary air to a location upstream of an exhaust gas purification catalyst arranged in an exhaust passage; a control valve that opens/closes a secondary air supply passage; a pressure detector that detects a pressure between the pump and the control valve; and a control unit that detects a first pressure in a first operating state where the control valve is closed, and detects a second pressure in a second operating state where the control valve is open, using the pressure detector. The control unit corrects at least one of the first and second pressures based on a first driving voltage for the pump in the first operating state and a second driving voltage in the second operating state, and estimates a secondary air flow rate based on the first and second pressures after correction.

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Susono, Japan

Koji Umezawa