Isuzu Motors Limited

Koichiro Yomogida

Futoshi Nakano

Yuji Sasaki

Akira Hirata

Nobutaka Ishii

Toshiaki Harunari

Kazuya Tomikawa

Yusuke Saigo

Kazutaka Ohishi

A control device for an internal combustion engine comprising an EGR passage () for connecting an intake passage () and an exhaust passage () with each other, an EGR valve () provided in the EGR passage (), and an intake throttle valve () provided in the intake passage () at an upstream side of the connection part with the EGR passage (). The control device comprises operational state detection means for detecting an operational state of the internal combustion engine, first control means for controlling opening and closing of the intake throttle valve () and the EGR valve () to adjust intake air volume if the operational state detection means detects a normal operational state, and second control means for controlling the intake throttle valve () at a predetermined constant opening degree and for controlling opening and closing of the EGR valve () to adjust an intake air volume if the operational state detection means detects a predetermined operational state.

Control device and method for internal combustion engine

A fuel injection control device includes an exhaust purification device for purifying an exhaust gas by catalytic action, an exhaust gas-temperature detection unit for detecting exhaust gas temperature, and a determination unit for determining the amount of the basic fuel injection and basic fuel injection timing from the operational status of a combustion engine, and a control unit for controlling the amount of the fuel injection and fuel injection timing. The control unit retards the fuel injection timing from the basic fuel injection timing when the exhaust gas temperature is lower than the temperature required for the catalytic activation of the exhaust purification device. The control unit also increases the amount of the fuel injection compared to the amount of the basic fuel injection to compensate for the loss of the torque output caused by the retarded fuel injection timing.

Fuel injection control device

An EGR control apparatus for a diesel engine which can stop EGR in advance of increase of a fuel injection quantity when acceleration of the engine comprises: EGR means () to adjust an EGR volume which is recirculated from an exhaust pipe () to an intake pipe (); filter means () to carry out a smoothening-process to an accelerator opening degree detected by an accelerator opening degree sensor; injection quantity determination means () to determine a target fuel injection quantity to be injected from an injector (), using the accelerator opening degree after smoothening-processed; and control means () to calculate a fuel injection quantity for judging EGR stop (Qcut), using the accelerator opening degree before smoothening-processed, to allow the EGR means () to carry out a decrease control for the EGR volume when the fuel injection quantity for judging EGR stop (Qcut) exceeds a predetermined threshold value (Hi).

EGR control apparatus for diesel engine

A fuel injection quantity control device includes: vehicle speed detection unit; gear position detection unit; engine revolution speed detection unit; accelerator opening degree detection unit; target acceleration value computation unit for finding a basic target acceleration value corresponding to the difference between the set limit vehicle speed and an actual vehicle speed and an upper limit value and lower limit value of the basic target acceleration value for each gear position in a map, limiting the basic target acceleration value with the upper limit value and lower limit value, and determining a target acceleration value; basic fuel injection quantity for vehicle speed limit computation unit for determining a basic fuel injection quantity for vehicle speed limit by feedback computation from the difference between the determined target acceleration value and the actual acceleration value; an accelerator required injection quantity computation unit for computing an accelerator required injection quantity from the engine revolution speed and accelerator opening degree; and vehicle speed limit injection quantity computation unit for selecting the smaller of the basic fuel injection quantity for vehicle speed limit and accelerator required injection quantity and setting it as a fuel injection quantity for vehicle speed limit.

Fuel injection quantity control device

A fuel injection control device includes an after treatment device for purifying exhaust gas by the action of a catalyst, an exhaust gas temperature detector for detecting the exhaust gas temperature, and a controller for controlling the fuel injection quantity and fuel injection timing. The controller executes an exhaust gas temperature increase control by post-injection when the exhaust gas temperature detected by exhaust gas temperature detection means is less than the activity temperature of the catalyst in the after treatment device. When executing the exhaust gas temperature increase control, the controller determines the target injection quantity of post-injection based on the difference between the exhaust gas temperature considered as a target and the actual exhaust gas temperature detected by the exhaust gas temperature detector and also determines the upper limit value of injection quantity of post-injection based on the actual exhaust gas temperature detected by the exhaust gas temperature detector, conducts control such that the actual injection quantity of post-injection becomes the upper limit value when the target injection quantity is equal to the upper limit value or higher, and conducts control such that the actual injection quantity of post-injection becomes the target injection quantity when the target injection quantity is less than the upper limit value.

The common rail fuel injection control device in accordance with the present invention computes a base duty (A) equivalent to a base target opening degree of a metering valve and a correction coefficient (B) based on the engine operation state, adds the value obtained by multiplying an oscillation duty (C) which oscillates periodically by the correction coefficient (B) to the base duty (A), and determines the final duty (D) equivalent to a final target opening degree of the metering valve.

Common rail fuel injection control device

The detected values of a common rail pressure that were detected by a pressure sensor are read within crank angle periods &#x394;t which are at least not more than half of a pumping cycle &#x394;T of a supply pump, the values detected within one pumping cycle preceding a reading time (for example, S(1), S(0), . . . S(&#x2212;4)) are averaged during each of the reading times, and the value thus obtained (for example, Pav()) is used as a common rail pressure after averaging processing, which is a representative value or a control value of the actual common rail pressure. The feedback control of common rail pressure is executed by using the values of common rail pressure after averaging processing thus computed by moving averaging. Consequently, the actual common rail pressure is converted into values suitable for control, and the feedback control of common rail pressure is executed with higher accuracy.

Filter processing device for detecting values of common rail pressure and common rail fuel injection control device

A fuel injection control device for executing multiple injection includes first means for determining the total injection quantity of fuel (Qtotal), second means for determining base injection quantities (QBsub) of each auxiliary injection, and third means which, when the sum (QBsubtotal) of base injection quantities (Qsub) of each of auxiliary injections is not larger than the value obtained by multiplying the total injection quantity (Qtotal) by a coefficient (K) (0<K&lE;1), computes the injection quantity (QTmain) of the main injection by subtracting the sum (QBsubtotal) from the total injection quantity (Qtotal), and when the sum (QBsubtotal) is larger than the value obtained by multiplying the total injection quantity (Qtotal) by the coefficient (K), computes the injection quantity (QTmain) of the main injection by reduction correcting the base injection quantities (QBsub) of auxiliary injections so that the sum (QBsubtotal&prime;) of injection quantities (QBsub&prime;) of auxiliary injections after the correction becomes not larger than the value obtained by multiplying the total injection quantity (Qtotal) by the coefficient (K), and by subtracting the sum (QBsubtotal&prime;) after the correction from the total injection quantity (Qtotal).

A fuel injection quantity control device for controlling an actual revolution speed En of an engine to a target revolution speed Eo, comprises difference computation unit for subtracting the actual revolution speed En from the target revolution speed Eo and finding the difference e therebetween; proportional term computation unit for multiplying the aforesaid difference e by the prescribed proportionality constant Kp and finding a proportional term output value Qp; integral term computation means for finding an integral term output value Qi which is obtained by integrating the product of the aforesaid difference e and the prescribed integration constant Ki; differential term computation unit for finding a differential term output value Qd which is obtained by multiplying the value obtained by differentiating the aforesaid difference e by the prescribed differentiation constant Kd; and injection quantity computation unit for adding up the proportional term output value Qp and the integral term output value Qi and determining the injection quantity.

A common rail fuel injection device for ensuring the main injection start timing by correcting a pulse start time of a main injection command pulse, in accordance with the length of an interval between the main injection and a pilot injection. The recovery degree of current energy for driving an injector varies in accordance with the length of the interval Tint from a pilot injection end (T ) to an main injection start time (T ), and this variation affects the main injection start time. By taking a longer value for an injector drive delay time (Td) as the length of the interval Tint is shorter, a pulse start time (T ) of a main injection command pulse CPm for performing the main injection is corrected as a more advanced timing, and hence the fuel injection for the main injection can be performed at a prescribed injection start timing.

Common rail fuel injection device

When common rail pressure Pr is predetermined pressure Prai, which is low such that it is lower than the pressure for the initiation of fuel injection by the injectors (step ), air-extraction pulse width Pwai, which is elected in accordance with a fixed value or the engine rotation speed (step ), is elected as the final pulse width Pwf (step ). Also, since air that is entrained with fuel is discharged at low pressure, along with fuel, from the pressure control chamber of the injectors, via a open/close valve, which opens based on pulse width Pwai, and via a discharge path, it is possible to avoid the effect, on the combustion characteristic, that arises due to the injection of entrained air, along with fuel, from nozzle holes into the combustion chamber.

An engine fuel injection control device for improving stability of engine rotation after startup by determining a limited fuel injection amount for cold condition when the engine is insufficiently warmed-up, in addition to a limited fuel injection amount for normal operating condition. The limited fuel injection amount for normal operating condition Qlimo is calculated by a normal condition limited fuel injection amount calculating unit ( ). The limited fuel injection amount for cold condition Qlimc is calculated by a cold condition limited fuel injection amount calculating unit ( ) on the basis of engine rotational speed Ne. When a water temperature Tw is lower than a prescribed value Twd and a lapse time Trun after shifting from startup condition to normal operating condition is less than a prescribed time Trund, a limited fuel injection amount selecting unit ( ) selects the larger of these values as a limited fuel injection amount Qlim.

Engine fuel injection control device

An engine fuel injection control device whereby appropriate engine output is obtained without generation of smoke, by determining a smoke limit fuel injection amount, using an inferred air intake amount when the engine operating condition is in a transient state etc. An inferred air intake amount calculation device ( ) calculates an inferred air intake amount by using the target fuel injection amount on the previous occasion and the engine rotational speed. If the air amount deviation between the inferred air intake amount and the detected air intake amount detected by a mass airflow sensor ( ) is more than a prescribed value, the detected air intake amount is deemed to be subject to detection lag. Then, the inferred air intake amount is selected as the final air intake amount, and the final fuel injection amount is calculated in accordance with this final air intake amount.

This invention provides a common rail fuel injection device, which ensures the functions of pilot injection even at high fuel pressure in the common rails, by changing the injection end delay period of the pilot injection in accordance with the fuel pressure in the common rail. The period displacement &Dgr;SOCp to be applied to the pulse start time of the pilot injection command pulse CPp, with respect to the top dead centre T , is set to a timing that is advanced by the interval period Tint, pilot injection end delay period Tdpe and injection pulse width Pwp for pilot injection, with respect to the main injection start time T

When the accelerator is actuated at startup of the engine, a value for target fuel-injection amount at startup Qst is output by a device for electing a target fuel-injection amount at startup 45, this value being selected by minimum value selecting means 44 as the smaller of two values that are an additional fuel injection amount at startup Qsa, which is calculated, on the basis of the previous target fuel-injection amount at startup Qst(&minus;1), by a device for calculating an additional fuel injection amount at startup 42, and a limit fuel-injection amount at startup Qsl, which is calculated, on the basis of accelerator pedal depression amount Ac, by a device for calculating a limit fuel-injection amount at startup 43. Addition to the fuel-injection amount can thus be limited in accordance with the accelerator actuation amount, and the generation of smoke suppressed.

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Fujisawa, Japan

Koichiro Yomogida