Isuzu Motors Limited

Takashi Haseyama

Tatsuo Mashiko

Takao Onodera

Takuro Iwashita

Shinji Gotou

Yoshinobu Watanabe

Kenji Hagio

Hitoshi Satou

Futoshi Nakano

Shigeru Ikeda

Akira Hirata

Wei Wu

Kouichirou Yomogida

Hiroyuki Oohira

Atsushi Matsunuma

Hitoshi Sato

Masashi Gabe

Naofumi Ochi

Yoshihisa Tashiro

Hiroyuki Ishikawa

Noriyuki Tsukamoto

Toshio Miyazaki

Akihiro Inamura

Hidetaka Shibata

Takeshi Igarashi

A diesel particulate filter ('DPF') system that suppresses clogging of a DPF and enhances convenience including accumulated particulate matter ('PM') quantity estimator for estimating an accumulated PM quantity in an idle state; and a long low idle forced regeneration unitthat if the accumulated PM quantity estimated by the accumulated PM quantity estimation estimator exceeds a predetermined quantity, performs long low idle forced regeneration that automatically performs regeneration of the DPF, and the long low idle forced regeneration unit, when a vehicle starts moving during long low idle forced regeneration, performs automatic regeneration of the diesel particulate filter while the vehicle is moving.

Diesel particulate filter system

In forced regeneration control of an exhaust gas purification device, data for control such as the number of meshes of a data map and the number of data maps for forced regeneration control is reduced and occurrence of torque shock is avoided by smoothly changing a fuel pressure. In the forced regeneration control of the exhaust gas purification device, when an operation state of an internal combustion engine is in a high-load operation state, normal injection control by stopping multi injection is carried out and according to a rotation speed and a load of the internal combustion engine, a region for control is divided into a multi-injection control region, a transition region, and a normal injection control region, and in the transition region, data for fuel pressure control obtained by interpolation of data for fuel pressure control on the multi-injection control region side and data for fuel pressure control on the normal injection control region side is used.

Control method of exhaust gas purification system and exhaust gas purification system

An exhaust gas purification system includes a diesel particulate filter ('DPF') which collects particulate matter ('PM') in exhaust gas, an exhaust pipe injector which performs exhaust pipe injection, and a DPF regeneration control unit which performs temperature rise control of an exhaust gas temperature by the exhaust pipe injection to regenerate the DPF when the PM collected by the DPF exceeds a fixed amount and which, during the regeneration, integrates an amount of time during which the exhaust gas temperature exceeds a PM combustion temperature and completes the regeneration when an integrated value thereof reaches a set regeneration completion value. The DPF regeneration control unit aborts the regeneration when, during regeneration, a total amount of the exhaust pipe injection exceeds an upper limit before the integrated value.

Exhaust gas purification system

An exhaust gas purification system with which a frequency of diesel particulate filter ('DPF') regeneration requests can be reduced during long low idle regeneration, thereby improving convenience, including a control unit that performs regeneration control on a DPF provided at an exhaust pipe of an engine. The control unit includes a particulate matter ('PM') accumulation amount predictor for predicting the amount of PM accumulated by calculating a cumulated value of the PM in an idling state. The control unit starts calculating the cumulated value of the PM by the PM accumulation amount predictor after a first predetermined time has elapsed since a detection of the idling state.

Forced regeneration start timing of a diesel particulate filter for purifying particulate matter in exhaust gas is judged based on a comparison of a differential pressure across the diesel particulate filter with a predetermined differential pressure threshold across the filter. The predetermined differential pressure threshold is set by multiplying a reference differential pressure threshold by a coefficient which varies stepwise or continuously depending on a mileage of a vehicle after previous forced regeneration. Consequently, particulate matter can be removed by burning while the amount of particulate matter accumulated unevenly in the filter is still small, and excessive temperature rise in the filter resulting from excessive accumulation of particulate matter during forced regeneration and melting-loss of the filter due to excessive temperature rise can be prevented.

Exhaust emission purification method and exhaust emission purification system

An exhaust emission purification system having a controller performing exhaust temperature rise control including multistage delay injection control for raising the exhaust temperature, if the exhaust gas temperature is lower than a predetermined judgment temperature, and performing particulate matter combustion removal control including post injection control, if the exhaust gas temperature becomes equal to or higher than the predetermined judgment temperature, when forced regeneration of a diesel particulate filter is carried out. The multistage delay injection control is forbidden when an idle operation state of an internal combustion engine occurs for a predetermined judgment time and a power take-off device is operating. A control method for exhaust emission purification is also provided sustaining a diesel particulate filter for purifying particulate matter in exhaust gas by executing forced regeneration while avoiding variation in engine speed, even if the power take-off device is operating during an extended idling operation.

Control method of exhaust emission purification system and exhaust emission purification system

An exhaust emission purification system and a related method of control, wherein an exhaust throttle valve is opened if an engine load reaches at least a predetermined first judgment value during execution of forced regeneration control, and generating an alarm of failure of the exhaust throttle valve if the engine load reaches at least a second judgment value which is larger than the predetermined first judgment value.

At regeneration control while a vehicle mounting an internal combustion engine () is parked, both an exhaust throttle valve () and an exhaust brake valve () are used and if a catalyst temperature index temperature (Tg) is lower than a predetermined first determining temperature (Tc), first exhaust gas temperature rise control is conducted that the exhaust brake valve () is set to a fully closed side and multiple injection is carried out in in-cylinder fuel injection control, while if a catalyst temperature index temperature (Tg) is equal to the predetermined first determining temperature (Tc) or above, second exhaust gas temperature rise control is conducted that the exhaust brake valve () is set to an open side, the exhaust throttle valve () is set to the fully closed side, and post injection is carried out in the in-cylinder fuel injection control. By this arrangement, while temperature rise efficiency of an exhaust gas flowing into a DPF () is enhanced, forced regeneration is carried out efficiently in a short time with avoiding overheat or abnormal combustion at the regeneration control of the DPF () while the vehicle is parked.

In regeneration control, when the catalyst temperature index temperature (Tg) using the temperature of the oxidation catalyst () as an index is below a predetermined first determination temperature (Tc), the engine speed of idling is brought to a predetermined first target engine speed (Nei) which is higher than the engine speed of idling (Nei) in the ordinary operation, and, further, multi-injection is carried out. On the other hand, when the catalyst temperature index temperature (Tg) is the predetermined first determination temperature (Tc) or above, the engine speed of idling is brought to a predetermined second target engine speed (Nei), which is lower than the predetermined first target engine speed (Nei) and is higher than the engine speed of idling (Nei) in ordinary operation, and, further, post injection is carried out, followed by raising of the temperature of an exhaust gas flown into a DPF apparatus () to a predetermined second determination temperature (Tc). According to the above constitution, in the regeneration control of the DPF apparatus () in an internal combustion engine (), the regeneration can be forcibly carried out with high efficiency while enhancing the temperature rise efficiency of the exhaust gas, and, at the same time, excessive rise in the exhaust temperature, a deterioration in fuel consumption, and the occurrence of noise are suppressed.

Method for controlling exhaust gas purification system and exhaust gas purification system

In an exhaust gas purification system () for conducting control of raising temperature of a DPF () by supplying an unburned fuel to an upstream side of an oxidation catalyst to oxidize it, a minimum value (Qumin) of a first upper limit value (Qu) acquired by subtracting a fuel injection amount (Qe) for in-cylinder combustion from a first combustible fuel amount (Qa) limited by an air/fuel ratio, a second upper limit value (Qu) acquired by subtracting the fuel injection amount (Qe) for in-cylinder combustion from a second combustible fuel amount (Qa) limited by an atmospheric pressure, and a third upper limit value (Qu), which is a third combustible fuel amount (Qa) which can be oxidized by the oxidation catalyst limited by a catalyst temperature index temperature (Tg, Tg) and an engine speed (Ne) is set as an upper limit value (Qu) for the unburned fuel supply amount (Qp). By this arrangement, at forced regeneration of the DPF (), the unburned fuel supplied into an exhaust gas is surely oxidized and generation of white smoke is prevented regardless of an operation state of an internal combustion engine ().

Exhaust gas purification method and exhaust gas purification system

An exhaust gas purification system including an exhaust gas purification device having an oxidation catalyst device including an oxidation catalyst and a diesel particulate filter ('DPF') arranged in order from an upstream side, or a DPF carrying an oxidation catalyst in an exhaust passage of an internal combustion engine. At regeneration of the DPF, when a catalyst temperature index temperature (Tg), indicating a temperature of the oxidation catalyst, becomes equal to a predetermined determining temperature (Tc) or above, a temperature of the DPF is raised by supplying an unburned fuel to the upstream side of the oxidation catalyst to thereby oxidize the unburned fuel by the oxidation catalyst. The predetermined determining temperature (Tc) is changed according to an engine speed Ne of the internal combustion engine. By so oxidizing the unburned fuel supplied into an exhaust gas by the oxidation catalyst, outflow of white smoke is prevented regardless of an operation state of the internal combustion engine.

A fuel injection control device that prevents a misfire is provided. The fuel injection control device comprises: target injection amount determination meansfor determining a target injection amount of each fuel injection, so that the amount of fuel to be supplied to a cylinder in one combustion cycle is supplied in a plurality of fuel injections; and fuel injection correction amount determination meansfor determining a fuel correction amount of one combustion cycle, wherein the fuel injection correction amount determination meansdistributes the correction amount among each fuel injection in accordance with the ratio of a target injection amount of each fuel injection in the cylinder.

Fuel injection control device

The present invention provides an engine exhaust gas purification device comprising a filter B provided in an exhaust passage () of an engine () for trapping particulate matter contained in the exhaust gas, a catalyst A for regenerating the filter B by burning the particulate matter trapped in the filter B, an EGR valve () provided in an EGR passage () linking the intake side and exhaust side of the engine, an injector () for injecting fuel into a cylinder, and control unit () for controlling the injector () and EGR valve (). During regeneration of the filter B, the control unit () close the EGR valve () when fuel injection from the injector () is controlled to supply unburned fuel components to the catalyst A, and open the EGR valve () when no fuel is injected from the injector () upon a request for speed reduction or the like. In so doing, residual unburned fuel components in the EGR passage () are scavenged by air.

Engine exhaust gas purification device

A method and system providing a vehicle condition detection means (C) for detecting the stopped and traveling state of a vehicle, and when the vehicle condition detection means (C) detects that the vehicle has stopped during operation of an exhaust gas temperature raising means (C), closing an exhaust gas throttling valve () in addition to continuing the operation of the exhaust gas temperature raising means (C), and subsequently, when the vehicle's traveling state is detected, opening the exhaust gas throttling valve () and continuing the operation of the exhaust gas temperature raising means (C). Accordingly, in terms of the regeneration of a continuous regeneration-type DPF device () capable of significantly reducing the frequency with which the driver is urged to stop the vehicle and perform forced regeneration, the exhaust gas can be efficiently maintained at a high temperature, and reliable burning of PM is possible even for driving patterns featuring frequent waiting at traffic signals in urban areas, even upon transition to the stationary idling condition during automatic traveling regeneration.

Control method for an exhaust gas purification system and an exhaust gas purification system

To provide an exhaust gas purifying system capable of forcibly regenerating DPF by efficiently raising the temperature of exhaust gas even when an exhaust gas temperature is very low at the time of low load and low engine speed such as an idling operation. In an exhaust purifying system () having an exhaust throttling valve () and a DPF () in an exhaust passage and having regeneration control means (P) for regenerating the DPF (), the regeneration control means (P) is provided with an exhaust gas temperature detection means (P), a fuel injection control means (P), and an exhaust throttling control means (P) and includes regeneration control for performing the exhaust gas temperature raising control through the multistage delay injection by the fuel injection control means (P) and through the exhaust throttling of the exhaust throttling valve ().

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Fujisawa, Japan

Takashi Haseyama