Isuzu Motors Limited

Isuzo Motors Limited

Masanobu Minezawa

Takao Onodera

Shinji Hara

Keiichi Iida

Yasuhisa Oomura

Shinichi Harada

Akihiro Sawada

Naofumi Ochi

Takuro Iwashita

Hirotaka Takahashi

Tetsuya Murata

Kouji Sakumoto

Takeshi Fukuoka

Shigeru Nihongi

Hiroyuki Oohira

Shin Amagasaki

Tomoyuki Kamijyou

Koji Sakumoto

Gouichi Akahoshi

Ken Hasegawa

Mami Hotta

Kouichi Takahashi

Yutaka Suzuki

Provided is an exhaust gas purification apparatus having a control device that monitors the transition of a detection value of each of an upstream NOx sensor and a downstream NOx sensor, and when the NOx purification rate of the SCR catalyst falls to a value of a first threshold or lower, generates an abnormality detection signal indicating that an over storage state has occurred in an SCR catalyst if the amount of change in the detection value of the upstream NOx sensor per unit time is at least a second threshold and the amount of change in the detection value of the downstream NOx sensor per unit time is at most a third threshold.

Exhaust gas purification device for internal combustion engine, and vehicle

A urea water supply system which performs permission determination by a control device based on a first parameter includes a cooling water temperature sensor, and a control device is configured to be able to store a result of the permission determination, and when a system control is restarted after the system control is stopped and a stop period is elapsed, it performs a shortening setting to shorten a time required for the permission determination based on the determination result stored at a time when the system is stopped and a cooling water temperature immediately after restarting.

Urea water supply system and control method therefor

A urea water solution injection system includes a urea water solution injection device for spraying a urea water solution into a portion of an exhaust passageway upstream of a selective catalytic reduction catalyst device, to reduce NOx in exhaust gas discharged from an internal combustion engine. Engine coolant is circulated through the urea water solution injection device to prevent freezing of the urea water solution. A crystal dissolution control unit performs crystal dissolution control on the urea water solution injection device by energizing at a preset amount of energization at a state where a urea water solution supply pump for supplying a urea water solution to the urea water solution injection device is kept stopped, and the crystal dissolution control unit performs the crystal dissolution control for a crystal dissolving energization time calculated in advance, after the engine is started but before a urea water solution is supplied.

Urea water injection system and method for preventing crystallization in urea water injection device

A diagnostic device for a sensorprovided in an exhaust passageof an internal combustion engineof a vehicle and detecting nitrogen compounds in exhaust gas, the diagnostic device including an offset diagnosis unitwhich diagnoses, during deceleration of the vehicle in which the internal combustion enginestops fuel injection, an offset amount of a sensor value of the sensorfrom a zero point based on the sensor value of the sensor value, and a diagnosis prohibition unitwhich prohibits the diagnosing of the offset amount when a flow rate of the exhaust gas of the internal combustion enginerapidly increases while the offset amount is diagnosed by the offset diagnosis unit

Diagnostic device and diagnostic system

An exhaust purification system that includes a selective catalytic reduction to purify NOx contained in an exhaust gas by using ammonia produced from urea water and an NOx sensor to acquire a value of the NOx contained in the exhaust gas, and the exhaust purification system includes: a reach time measurement unit that measures a reach time of the NOx value acquired by the NOx sensor, the reach time being a required time for the NOx value to reach, from a first predetermined determinative NOx value, a second predetermined determinative NOx value, which is higher than the first determinative NOx value; and a determination unit that determines that malfunction occurs in the NOx sensor when the reach time measured by the reach time measurement unit is equal to or shorter than a first predetermined determinative time.

Exhaust purification system

An exhaust purification system can prevent a NHslip caused by an excessive injection of urea water, and includes: an SCR that purifies NOx contained in an exhaust gas using ammonia, as a reducing agent, produced from urea water; a urea water injection device that injects the urea water into an exhaust passage upstream from the SCR; an estimated-adsorption-amount calculation unit that calculates an estimated adsorption amount of the ammonia adsorbed in the SCR; an injection control unit that executes an injection control of the urea water injection device based on the estimated adsorption amount; and an estimated-adsorption-amount change unit that changes the estimated adsorption amount used for the injection control into a value increased or decreased by a predetermined amount when a predetermined condition is established that can cause a difference between an actual adsorption amount of the ammonia adsorbed in the SCR and the estimated adsorption amount.

Exhaust purifying system

The exhaust gas purification system includes a SCR, an NOx sensor which is provided on a downstream side of the SCR, and an NOx purifying controller which controls an amount of urea water being ejected to the SCR and performs an abnormality diagnosis based on a detection value of the NOx sensor, wherein the exhaust gas purification system includes an exhaust gas temperature sensor which acquires temperature of the exhaust gas flowing into the SCR, a temperature increasing rate calculating unit which calculates a temperature increasing rate at which the exhaust gas temperature acquired by the exhaust gas temperature sensor reaches a second temperature from a predetermined first temperature, and a prohibiting unit which prohibits abnormality diagnosis by the NOx purifying controller in a case in which the temperature increasing rate calculated by the temperature increasing rate calculating unit is higher than a predetermined determination threshold value.

Exhaust gas purification system

A clogging detection device includes a urea water sensor which detects temperature in a urea water tank, a pressure sensor which detects pressure in a urea water feed line, an exhaust gas temperature sensor disposed in an exhaust pipe upstream of a selective catalytic reduction device, and a determination unit. When a key switch is turned on, the determination unit performs a startup control to drive a supply pump and increase the pressure in a pipe segment extending to a dosing value. If a detection value of the exhaust gas temperature sensor is no greater than a predetermined temperature, and a detection value of the urea water sensor is no smaller than a freezing temperature, then the determination unit performs emptying control for returning the urea water from the pipe segment to the urea water tank to detect clogging of the pipe segment from the detection value of the pressure sensor.

Urea water pipe clogging detection device for urea selective catalytic reduction

A urea spray selective catalytic reduction ('SCR') control system includes an SCR catalyst provided in a discharge pipe of an engine, a dosing valve for injecting urea water at an upstream side of the SCR catalyst, and NOx sensors, wherein the system controls injection of the urea water from the dosing valve. The system includes a plurality of NOx model maps corresponding to an atmospheric pressure condition, an outdoor air temperature, and an engine water temperature, and determines an amount of NOx from each NOx model map on a basis of detection values of an atmospheric pressure detector, an outdoor air temperature detector, and an engine water temperature detector, and controls an amount of injection of the urea water from the dosing valve on a basis of the amount of NOx thus determined.

Urea spray selective catalytic reduction control system

A selective catalytic reduction (SCR) system that can prevent fixation of urea solution to an interior of a dosing valve when the urea solution is not injected through the dosing valve. An SCR system closes a dosing valve when the exhaust gas temperature is lower than a temperature at which an SCR catalyst becomes active and is provided with a fixation prevention system that opens the dosing valve and controls a supply module to feed the urea solution in the dosing valve back to a urea tank to prevent fixation of the urea solution to the interior of the dosing valve, when the exhaust gas temperature is equal to or higher than a temperature at which the urea solution crystallizes and lower than the temperature at which the SCR catalyst becomes active.

Selective catalytic reduction system

An exhaust gas purification system includes a dosing control unit that controls a supply module to supply urea water between a dosing valve and a urea tank in order to remove urea water accumulated in the dosing valve, when receiving a diesel particulate filter regeneration authorization request from an engine control unit, and then transmits the authorization to the engine control unit, when determining that an NHamount of a selective reduction catalyst is less than or equal to a prescribed value.

A recovery control system that allows a dosing valve to recover from a malfunction to a normal state, or a liquid feed line through which urea solution is fed to recover from clogging to a normal state. An abnormality detector detects an abnormality of the dosing valve and a recovery controller controls a supply module to feed urea solution in the dosing valve back to an urea tank when the abnormality detector detects the abnormality.

Recovery control system

A selective catalytic reduction system (SCR) that reduces a burden on a battery resulting from energization of a heater and a decrease in time during which an NOx concentration cannot be detected. The SCR system includes: an SCR device; a dosing valve; NOx sensors; an urea solution injection control unit; electric heaters for raising respective temperatures of the NOx sensors to a sensor operating temperature; and an energization permission unit that prohibits energization of the heaters at the time of a start of an engine and permits energization of the heaters when engine revolutions become equal to or exceed a preset energization permission threshold value and such state lasts for a period of time equal to or exceeding a preset stabilization wait time.

A selective catalytic reduction thawing control system that can distinguish between a thawing failure and a malfunction and can prevent a malfunction of a supply module ('SM') pump. The thawing control system includes a thawing control unit that detects a pressure inside the supply module when the SM pump is operated, and stops the operation of the SM pump and continues thawing of urea water when the pressure is less than a predetermined value.

SCR thawing control system

A selective catalytic reduction system that can defrost urea aqueous solution without interruption of warm air of an engine or heating of a vehicle cabin. The system includes a defrosting control unit to open a tank heater valve at the time of starting the engine and close the tank heater valve when the temperature of the urea aqueous solution detected by a temperature sensor reaches a predetermined defrosting completion determination value, and a warm air priority control unit to prohibit the opening of the valve by the defrosting control unit when the temperature of the cooling water is less than a predetermined defrosting permission value and permit the opening of the valve by the defrosting control unit when the temperature of the cooling water is equal to or more than the defrosting permission value.

Growing community of inventors

Fujisawa, Japan

Masanobu Minezawa