Bosch Corporation

Kenichi Tanioka

Masanori Watanabe

Takeshi Miyamoto

Fumiyasu Kurogi

A control apparatus that includes a measured NOx purification ratio calculation unit calculating a measured NOx purification ratio of a reduction catalyst based on outputs of NOx sensors and provided upstream and downstream of the reduction catalyst reducing nitrogen oxide in an exhaust gas, an estimated NOx purification ratio calculation unit calculating an estimated NOx purification ratio of the reduction catalyst based on a temperature of the reduction catalyst, a flow rate of the exhaust gas, and an absorption amount of the reducing agent by the reduction catalyst, and a reducing agent concentration estimation unit estimating a concentration of the reducing agent injected from a reducing agent injection valve based on the measured NOx purification ratio and the estimated NOx purification ratio.

Control apparatus, exhaust purifying apparatus for internal combustion engine, and control method for exhaust purifying apparatus

To provide an exhaust purifying system and a method for controlling the exhaust purifying system that avoid occurrence of clogging, breakage, or the like of a reducing agent injection valve caused by the solidification of a reducing agent and prevent reduction in the efficiency of reducing agent recovery processing and exhaust gas purification. An exhaust purifying system and a method for controlling the exhaust purifying system according to an aspect of the present invention is configured to detect the injection valve temperature of the reducing agent injection valve according to detection of turn-off of an ignition switch for stopping the internal combustion engine or detection of an injection stop of the reducing agent injection valve, whichever is earlier, calculate the waiting time until reducing agent recovery processing starts based on the injection valve temperature, and permits the reducing agent recovery processing under condition of the detection of turn-off of the ignition switch and an elapse of the waiting time.

Control techniques of exhaust purification system and exhaust purification system

An exhaust gas purification system abnormality diagnosing device includes: a sensor value detecting means that reads a sensor signal of a specified gas concentration sensor to detect a gas concentration; a limiting device controlling means which, when the gas concentration has become equal to or greater than a predetermined start-of-diagnosis threshold value or when a difference obtained by subtracting from the gas concentration an estimated NOconcentration on a downstream side of a selective reduction catalyst obtained by computation has become equal to or greater than a predetermined start-of-diagnosis threshold value, increases the quantity of ammonia capable of being adsorbed by the selective reduction catalyst by raising the pressure inside an exhaust gas passageway with a passageway area limiting device disposed on the downstream side of the selective reduction catalyst; and a determining means that determines the abnormal state on the basis of the gas concentration or the difference after the pressure inside the exhaust gas passageway has been raised.

Exhaust gas purification system abnormality diagnosing device and abnormality diagnosing method, and exhaust gas purification system

A control device and method for exhaust gas purification that can prevent the adsorption amount from becoming excessively lower than the saturated adsorption amount and can prevent the reduction efficiency of the reduction catalyst from degrading, including a device which can predict a transition of the temperature of the reduction catalyst and determine whether that temperature is decreasing; an apparatus which can control injection of the reducing agent according to a first amount that is smaller than a saturated amount corresponding to the temperature of the catalyst if it is determined that the temperature does not decrease continuously for a time; and a second apparatus which can control the injection of the reducing agent according to a second amount that is larger than the first amount and smaller than the saturated amount if it is determined that the temperature of the reduction catalyst continuously decreases for a time.

Growing community of inventors

Saitama, Japan

Kenichi Tanioka