Toyota Jidosha Kabushiki Kaisha

Denso Corporation

Shigehiro Matsuno

Tatsuhisa Yokoi

Yasuhiko Otsubo

Hiroki Matsuoka

Takayoshi Inaba

Jun Tahara

Yasuo Harada

Ikuo Hoda

Ryouhei Kusunoki

Hidetomo Horikawa

Ryoichi Kitaoka

Masataka Miyazaki

An adding time a of a fuel addition to an exhaust system is limited to a guard value G or less during an adding period A of a concentrated intermittent fuel of a catalyst recovery control. Accordingly, a one-time fuel adding amount from an adding valveis limited to be equal to or less than a predetermined value, and it is possible to prevent such a great amount of unburned fuel component that cannot be fully purified by a NOx catalyst from being supplied to the NOx catalyst during the adding period A. Further, if a total amount (GF+Q)&#xb7;t of the unburned fuel component supplied to the NOx catalyst during the adding period A reaches an allowable upper limit value UL, the concentrated intermittent fuel addition is canceled and a suspend period B is forcibly started. Accordingly, it is possible to prevent a total amount of such a great amount of unburned fuel component that cannot be fully purified by the NOx catalyst from being supplied to the NOx catalyst during the adding period A. Therefore, generation of white smoke in exhaust gas of the internal combustion engine by an excessive supply of the unburned fuel component to the NOx catalyst at a time of executing catalyst recovery control can be prevented.

Exhaust gas purification apparatus of internal combustion engine

A diesel engine includes: a PM filter provided in its exhaust passage; a fuel injection valve for performing post fuel injection in a cylinder of an engine body in addition to primary fuel injection, in order to supply fuel to the PM filter, to maintain its purification performance; an oil level sensor for detecting a degree of dilution of engine oil; and a first indicator lamp that is turned on to indicate that the engine oil needs to be changed when the degree of dilution of engine oil detected by the oil level sensor is equal to or greater than an allowable level. The vehicle diesel engine overrides the prohibition of the post fuel injection until a distance traveled by the vehicle after the indicator lamp is turned on reaches a predetermined distance.

Vehicle diesel engine and control method of the same

If an exhaust throttle valve changes to ON state from OFF state under a filter regeneration control condition for regenerating a PM filter, a differential pressure sensor detects a change of a differential pressure following an operation of the exhaust throttle valve. An increase in an exhaust backpressure is calculated based upon the change in the differential pressure. If the increase in the exhaust backpressure is lower than a predetermined value, the operation of the exhaust throttle valve is determined to be malfunctioning.

Exhaust gas purification system for internal combustion engine and exhaust gas purification method therefor

A regeneration controller for an exhaust purification apparatus () of an engine () that appropriately burns particulate matter accumulated in the exhaust purification apparatus. The regeneration controller includes an ECU () that determines whether an estimated accumulation amount (PMsm) of particulate matter deviates from an actual accumulation amount. When the estimated accumulation amount is less than or equal to a maximum value (BUpm) and an exhaust pressure difference (&#x394;P/GA) is greater than a correction reference value (Dp), the ECU adds a correction value corresponding to the exhaust pressure difference to the estimated accumulation amount. This causes the estimated accumulation amount to approach the actual accumulation amount.

Regeneration controller for exhaust purification apparatus of internal combustion engine

A regeneration controller for preventing a large amount of particulate matter from being suddenly burned without increasing the frequency a heating process is performed. The regeneration controller includes an ECU() for heating an exhaust purification apparatus to eliminate the particulate matter accumulated in the exhaust purification apparatus when an estimated accumulation amount is greater than a reference accumulation amount. The ECU() obtains the estimated accumulation amount by estimating the amount of particulate matter accumulated in the exhaust purification apparatus. Furthermore, the ECU () changes modes for heating an exhaust purification apparatus when the regeneration controller is heated and an estimated accumulation amount is within a mode change range.

A regeneration controller for an exhaust purification apparatus () of an engine () that appropriately burns particulate matter accumulated in the exhaust purification apparatus. The regeneration controller includes an ECU () that determines whether an estimated accumulation amount (PMsm) of particulate matter deviates from an actual accumulation amount. When the estimated accumulation amount is less than or equal to a maximum value (BUpm) and an exhaust pressure difference (&Dgr;P/GA) is greater than a replacement reference value (Dp), the ECU replaces the estimated accumulation amount with a greater replacement amount (UPpm). This causes the estimated accumulation amount to approach or to be the same as the actual accumulation amount.

An exhaust purifying apparatus for an internal combustion engine includes an exhaust purifying mechanism, a fuel adding device, an electronic control device. The exhaust purifying mechanism is located in an exhaust passage and traps particulate matter. The fuel adding device adds fuel to exhaust gas that passes through the mechanism. The electronic control device detects a pressure difference between a section upstream and a section downstream of the exhaust purifying mechanism. While the fuel adding device is adding fuel to exhaust gas, the electronic control device compares the pressure difference that is detected at a predetermined point in time with the pressure difference reference value. When the pressure difference exceeds the pressure difference reference value, the electronic control device sets the manner of adding fuel to intermittent fuel addition. As a result, the exhaust purifying apparatus decreases the amount of particulate matter that remains in the exhaust purifying mechanism.

Exhaust purifying apparatus for internal combustion engine

A regeneration controller that prevents overheating when performing burn-up heating for completely burning particulate matter by intermittent fuel addition to an exhaust system or intermittent increase of fuel addition to the exhaust system. The regeneration controller includes first and second exhaust temperature sensors (), each detecting the exhaust temperature at a location downstream from the exhaust purification apparatus. An ECU () determines the timing for stopping fuel addition to the exhaust system or increase of fuel addition to the exhaust system based on the elapsed time of fuel addition to the exhaust system or increase of fuel addition to the exhaust system.

An exhaust purifying apparatus for an internal combustion engine having a DPNR converter (), a fuel adding device (), and an electronic control device () is provided. The DPNR converter () is located in an exhaust passage () of the internal combustion engine (). The DPNR converter () traps particulate matter in exhaust gas. The fuel adding device () adds fuel to exhaust as that passes through the DPNR converter (). The electronic control device () estimates a combustion rate of particulate matter in the DPNR converter () in a state where the fuel adding device () adds fuel to the exhaust gas. Based on the estimated combustion rate, the electronic control device () sets a manner of adding fuel by the fuel adding device (). As a result, the exhaust purifying apparatus suppresses excessive temperature increase of a DPNR converter () to which fuel is added.

An exhaust purifying apparatus for an internal combustion engine includes execution means, wherein, when an accumulation amount of particulate matter about a catalyst becomes less than a first determination value after a PM elimination control is started, the execution means executes burn-up control. Stopping means stops the PM elimination control based on an end of the burn-up control. Forcibly ending means forcibly ends the burn-up control when time elapsed since the accumulation amount of particulate matter about the catalyst has dropped to a second determination value reaches a predetermined time. Therefore, the exhaust purifying apparatus is capable of completely burning particulate matter in a PM filter, and suppresses degradation of fuel economy.

Exhaust purifying apparatus and exhaust purifying method for internal combustion engine

In an exhaust purifying apparatus, a fuel adding valve () supplies unburned fuel to an exhaust passage () of a diesel engine () so that particulate matter collected in a catalytic converter () is burned and removed. The supply of unburned fuel from the fuel adding valve () is executed even after an electronic control unit () determines that particulate matter in the catalytic converter () has been burned and removed. This reduces the amount of particulate matter remaining unburned in the catalytic converter ().

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Toyota, Japan

Shigehiro Matsuno