Abstract: 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 (42). The limited fuel injection amount for cold condition Qlimc is calculated by a cold condition limited fuel injection amount calculating unit (43) 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 (45) selects the larger of these values as a limited fuel injection amount Qlim.

Abstract: 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 (42) 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 (34) 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.

Abstract: 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 T7, 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 T6.

Abstract: 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(−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.

Abstract: 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 (T4) to an main injection start time (T6), 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 (T5) 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.

Abstract: 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 T7, 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 T6.

Abstract: The present invention provides an engine fuel-injection control device that improves startup efficiency and suppresses the generation of smoke by limiting any addition to the fuel injection amount at startup to only when the accelerator is actuated and in accordance with the amount of accelerator actuation.

Abstract: The present invention provides a common rail fuel injection device, by means of which it is possible to discharge air, which is entrained with fuel in the fuel supply path, from injectors, whilst avoiding any effect on the combustion characteristic, by adopting an existing common rail fuel injection device to which no changes have been made.

Abstract: A fuel injection control device of an engine having a plurality of cylinders, that prevents sudden change in combustion condition. The control device calculates a basic amount of fuel to be injected into cylinders. The controller then decides an amount of adjustment ultimately made to the basic amount of fuel based on an engine revolution speed difference between the cylinders. The adjustment is stepwise made to the basic amount of fuel so that a total amount of fuel gradually increases or decreases. Since a steep change does not occur in the total amount of fuel, the combustion condition does not change suddenly and the engine does not vibrate.

Abstract: 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 (42). The limited fuel injection amount for cold condition Qlimc is calculated by a cold condition limited fuel injection amount calculating unit (43) 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 (45) selects the larger of these values as a limited fuel injection amount Qlim.

Abstract: 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 (42) 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 (34) 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.

Abstract: A fuel injection control device of an engine having a plurality of cylinders, that prevents sudden change in combustion condition. The control device calculates a basic amount of fuel to be injected into cylinders. The controller then decides an amount of adjustment ultimately made to the basic amount of fuel based on an engine revolution speed difference between the cylinders. The adjustment is stepwise made to the basic amount of fuel so that a total amount of fuel gradually increases or decreases. Since a steep change does not occur in the total amount of fuel, the combustion condition does not change suddenly and the engine does not vibrate.