Bosch Corporation

Hiroyuki Kasahara

A rationality diagnosis method and a rationality diagnosis apparatus for a sensor inside a tank are provided. The rationality diagnosis method and the rationality diagnosis apparatus can accurately and easily perform a diagnosis to determine whether rationality of all sensors is maintained. The rationality diagnosis method for the sensor inside the tank performs a rationality diagnosis of a concentration sensor, a liquid level sensor and a temperature sensor that are provided inside the tank that stores liquid. The rationality diagnosis method is characterized by diagnosing whether the rationality is lost in one of the concentration sensor, the liquid level sensor and the temperature sensor by determining whether there exists any contradiction between respective sensor values of the concentration sensor, the liquid level sensor and the temperature sensor.

Rationality diagnosis method and rationality diagnosis apparatus for sensor inside tank

A control device for a reducing agent supply apparatus for controlling the reducing agent supply apparatus having reducing agent collecting means for collecting a reducing agent inside reducing agent supply paths in an exhaust gas purification apparatus that adds the reducing agent to an exhaust gas upstream side of a reducing catalyst disposed inside an exhaust gas passageway of an internal combustion engine, and reduces and purifies nitrogen oxides contained in exhaust gas using the reducing catalyst, includes: a stop detection portion that detects when the internal combustion engine stops; a reducing agent collecting means control portion that starts collection of the reducing agent inside the reducing agent supply paths when the internal combustion engine stops; and an injection valve control portion that keeps a reducing agent injection valve closed when the reducing agent collecting means starts operating and opens the reducing agent injection valve after a predetermined time period elapses.

Control device of reducing agent supply apparatus, reducing agent collection method, and exhaust gas purification apparatus

An oxidation catalyst fault diagnosis unit and fault diagnosis method. An oxidation catalyst fault diagnosis unit which performs fault diagnosis of an oxidation catalyst placed on the downstream side of the reduction catalyst, the oxidation catalyst fault diagnosis being equipped with a reducing agent dosage calculating portion that sets a dosage of the reducing agent such that a predetermined quantity of the ammonia flows out to the downstream side of the reduction catalyst, an oxidation efficiency calculating portion that obtains the efficiency with which the predetermined quantity of ammonia flowing out to the downstream side of the reduction catalyst is oxidized by the oxidation catalyst when the predetermined quantity of ammonia passes through the oxidation catalyst, and a fault determining portion that performs determination of whether or not the oxidation catalyst is faulty by comparing the oxidation efficiency with a predetermined reference value.

Oxidation catalyst fault diagnosis unit and oxidation catalyst fault diagnosis method and internal combustion engine exhaust purification apparatus

A temperature sensor plausibility diagnosis unit performs plausibility diagnosis of a temperature sensor disposed inside a storage tank in an exhaust purification apparatus of an internal combustion engine that delivers an additive inside the storage tank to an exhaust pipe upstream of a reduction catalyst and selectively reduces and purifies NOin the exhaust. The temperature sensor plausibility diagnosis unit includes an additive heat capacity calculating portion that calculates the heat capacity of the additive, a heat quantity variation calculating portion that calculates an increase or decrease in the quantity of heat that the additive receives, and a plausibility diagnosing portion that determines the plausibility of the temperature sensor by comparing an estimated temperature course of the additive estimated from the heat capacity of the additive and the increase or decrease in the quantity of heat with a sensor temperature course of the additive detected by the temperature sensor.

Growing community of inventors

Saitama, Japan

Hiroyuki Kasahara