JP2002155783A - Fuel injection control device for diesel engine - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To reduce emissions, fuel consumption and combustion noise by correcting and controlling main injection timing, pilot injection timing and pilot injection amount based on delay of parameters such as rail pressure during transient operation. . SOLUTION: Pilot injection can be realized before main injection of fuel. In addition to detecting the actual values of the parameters (catalyst temperature, intake air amount, EGR rate, rail pressure) that change according to the engine operating state and affect the combustion state, the target values of the parameters are set. The main injection timing, the pilot injection timing, and the pilot injection amount are corrected based on the delay (ratio) of the actual value to the target value of the parameter.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel injection control system for a diesel engine, and more particularly to a fuel injection control system in which fuel injection is divided into a main injection and a small amount of pilot injection preceding the fuel injection during one cycle according to an operating condition. The present invention relates to a fuel injection device that can be improved.

[0002]

2. Description of the Related Art Conventionally, in a diesel engine, a method of injecting a small amount of fuel as so-called pilot injection prior to main injection in order to reduce combustion noise and suppress NOx has been known.

[0003] In order to optimize the timing of the main injection and pilot injection and the pilot injection amount, a correction coefficient is calculated based on the detected engine coolant temperature during engine warm-up from the start to the end of warm-up. A technique for correcting the main injection timing, the pilot injection timing, or the pilot injection amount based on the correction coefficient is known.

[0004] Such conventional fuel injection control will be briefly described with reference to FIG. For example, when obtaining the final command value TMITF of the main injection timing, the basic main injection timing TMIT based on the basic map (see FIG. 3) and the water temperature correction amount TMHh based on the water temperature correction map (see FIG. 4).
os (MIT) and a water temperature correction coefficient THhos (MIT) are calculated based on a water temperature correction coefficient map (see FIG. 5), and a final command value TMIFT is obtained based on these values.

Similarly, the final command value TPITF of the pilot injection timing is also calculated based on a basic pilot injection timing map, a water temperature correction map, and a water temperature correction coefficient map which are individually prepared.
It is obtained based on IT, a water temperature correction amount TMHhos (PIT), and a water temperature correction coefficient THhos (PIT).

Similarly, the final command value T of the pilot injection amount
PQfF is also a basic pilot injection amount TPQf, which is obtained based on a pilot injection amount basic map, a water temperature correction map, and a water temperature correction coefficient map which are individually prepared.
Water temperature correction amount TMHhos (PQf), water temperature correction coefficient TH
hos (PQf).

[0007]

However, such correction based on the engine coolant temperature is not sufficient. For example, parameters such as the intake air amount, the EGR rate, the rail pressure, or the exhaust temperature (catalyst temperature) that change according to the engine operating state and affect the combustion state are the actual values (the transient values) for the target value during the transient operation. (Measured value or predicted value) tends to be delayed, and due to such a delay, the main injection timing, the pilot injection timing and the pilot injection amount deviate from the optimal values, and the engine operation performance such as ignitability. May be adversely affected.

The present invention has been made in view of such a problem, and the final command value of the main injection timing, the pilot injection timing, or the pilot injection amount is accurately determined due to the delay of the above parameters. It is an object of the present invention to perform accurate correction control even under operating conditions that are difficult to obtain to improve engine operation performance.

[0009]

SUMMARY OF THE INVENTION Therefore, an invention according to claim 1 is a fuel injection control device for a diesel engine capable of performing pilot injection before main injection of fuel, the fuel injection control device changing according to the engine operating state. Means for obtaining the actual value of at least one parameter that affects the combustion state, and means for setting a target value of the parameter, and based on a delay of the actual value with respect to the target value of the parameter during transient operation. Thus, at least one of the main injection timing, the pilot injection timing and the pilot injection amount is corrected.

That is, during the transient operation, the actual values of various parameters that affect the combustion state tend to lag behind the target values, so that the emission, fuel consumption, combustion noise, and the like are likely to be deteriorated. Therefore, in the present invention, during the transient operation, the deterioration of the emission, fuel consumption and combustion noise during the transient operation is performed by performing correction control of the main injection timing, the pilot injection timing or the pilot injection amount based on the delay of the above parameter. Thus, the driving performance can be improved.

The above parameters include an intake air amount,
Examples include the EGR rate, the rail pressure of the common rail, and the exhaust temperature (catalyst temperature). The actual values of these parameters may be detected directly, or may be estimated from other parameters such as the engine speed and the intake air temperature. For example, the intake air amount is preferably directly detected by an air flow meter. Further, the EGR rate is determined by an EGR flow rate provided in an EGR flow path communicating the intake passage and the exhaust passage.
It can be detected indirectly from the opening of the valve. Further, the rail pressure is preferably detected directly by a rail pressure sensor. The exhaust gas temperature and the catalyst temperature are preferably directly detected by a temperature sensor.

In the invention according to claim 2, the parameter includes an intake air amount, and at least one of a main injection timing, a pilot injection timing, and a pilot injection amount is determined based on a ratio of an actual value of the intake air amount to a target value. It is characterized in that one is corrected.

That is, the transient operation involves a delay in the amount of intake air, so that accurate correction control is performed based on such a delay in the amount of intake air, that is, the ratio of the actual value to the target value, so that emission and fuel consumption can be reduced. Further, it is possible to further reduce combustion noise and the like.

In the invention according to claim 3, the parameter includes an EGR rate, and at least one of a main injection timing, a pilot injection timing, and a pilot injection amount is determined based on a ratio of an actual value to a target value of the EGR rate. It is characterized by correction.

That is, during the transient operation, the EGR rate is inevitably accompanied by a delay due to the capacity of the EGR flow path, the collector capacity, and the like. By performing accurate correction control based on the above, it is possible to further reduce emissions, fuel consumption, combustion noise, and the like.

According to a fourth aspect of the present invention, there is provided a fuel injector of a common rail type, wherein the parameters include a rail pressure, and a main injection timing and a pilot injection timing are determined based on a ratio of an actual value of the rail pressure to a target value. And at least one of the pilot injection amount is corrected.

That is, during a transient operation such as acceleration or deceleration, the rail pressure is inevitably accompanied by a delay, so that combustion noise and emission are likely to be deteriorated. Therefore, as in the invention according to claim 4, by performing accurate correction control based on the delay of the rail pressure, that is, the ratio of the actual value to the target value, the emission, fuel consumption, combustion noise, and the like are further reduced. be able to.

According to a fifth aspect of the present invention, a catalyst is provided in the exhaust passage, and the parameter includes an exhaust temperature or a catalyst temperature, and the main injection is performed based on a ratio of the actual value of the exhaust temperature or the catalyst temperature to a target value. It is characterized in that at least one of the timing, the pilot injection timing and the pilot injection amount is corrected.

For example, during a transient operation in a low temperature state,
In addition to the insufficient catalyst carrier temperature, the exhaust gas flow rate changes abruptly, so that the emission is particularly likely to deteriorate. Therefore, such an exhaust gas temperature or a catalyst temperature can be controlled by performing accurate correction control based on the delay of the exhaust gas temperature or the catalyst temperature, that is, the ratio of the actual value to the target value, as in the invention according to claim 5. The main injection timing, pilot injection timing, and pilot injection amount can be accurately corrected, fuel consumption and combustion noise can be further reduced, and the exhaust gas temperature and catalyst temperature can be quickly brought close to target values. Can be effectively reduced.

More preferably, a transient correction value is calculated based on a ratio of an actual value to a target value of the parameter, and the main injection timing and the pilot injection are calculated based on the transient correction value. When at least one of the timing and the pilot injection amount is corrected, and the transient correction value is greater than 1, the main injection timing is retarded, the pilot injection timing is retarded, or the pilot injection amount is reduced, and the transient correction value becomes 1 If smaller, the main injection timing is advanced, the pilot injection timing is advanced, or the pilot injection amount is increased.

As described above, by using the transient correction coefficient obtained based on the ratio of all parameters, accurate correction control can be performed while simplifying the control.

[0022]

According to the present invention, during the transient operation, the main injection timing and the pilot injection timing are determined based on the delay of the actual value from the target value of the parameter that changes according to the engine operating state and affects the combustion state. And at least one of the pilot injection amounts, it is possible to reliably prevent a decrease in emissions, fuel consumption and combustion noise during transient operation due to such a delay in parameters, and to improve engine operation performance such as ignitability. Improvement can be achieved.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 shows the overall configuration of a fuel injection control device for a diesel engine according to an embodiment of the present invention.

The engine body 1 includes various auxiliary machines 7,
A common rail type fuel injection device including a plurality of injection valves 5 for injecting fuel supplied from a common rail 6 as a pressure storage chamber to each cylinder is provided. Also, the engine body 1
Are provided with a water temperature sensor 2 for detecting an engine cooling water temperature, an engine speed sensor 4 for detecting an engine speed (crank angle), and a rail pressure sensor 14 for detecting a rail pressure of the common rail 6.

The intake passage 9 is provided with an air flow meter 3 for detecting the amount of intake air. Exhaust passage 10
A catalyst 16 is provided, and an exhaust temperature sensor 17 for detecting the exhaust gas temperature on the upstream side of the catalyst and a catalyst temperature sensor 18 for detecting the temperature of the catalyst 16 are provided. An EG that communicates between the intake passage 9 and the exhaust passage 10
The R flow path 11 is provided with an EGR valve 12 for controlling the exhaust gas recirculation amount. In addition, 15 is a turbocharger as a supercharger.

The above various sensors and accelerator opening sensor 1
Control signals such as output signals from the injection valve 5 and the auxiliary equipment 7 are output to the control unit 8 in addition to the detection signal from the control unit 3. The control unit 8 determines the current engine operating state based on these control signals,
In addition to performing general engine control processing such as R control, it controls the fuel injection amount, injection pressure, and injection timing from the injection valve 5.

More specifically, by controlling the input signal to the control valve in the injection valve 5 according to the operating conditions, the fuel injection can be divided into pilot injection and main injection. Has become. In this pilot injection, by injecting a small amount of fuel in advance before the main injection, effects such as improvement of ignitability, reduction of NOx emission by reduction of initial combustion amount, suppression of combustion noise by reduction of pressure rise rate, etc. There is. For this reason, for example, during cold periods, pilot injection is applied mainly to improve ignitability, and at medium load or the like, pilot injection is applied when it is desired to suppress combustion noise.

Further, as will be described later, target values of the intake air amount, the EGR rate, the rail pressure, and the catalyst temperature (exhaust gas temperature) are set with reference to a preset operation map. The main injection timing, the pilot injection timing, and the pilot injection amount are corrected and controlled based on the delay (ratio) of the actual value (actually measured value or estimated value). In this embodiment, the actual value of the intake air amount is directly detected by the air flow meter 3, and the actual value of the EGR rate is obtained indirectly from the opening degree of the EGR valve 12, etc., and the actual value of the rail pressure is obtained. Is detected directly from the rail pressure sensor 14, and the actual values of the exhaust gas temperature and the catalyst temperature are directly detected from the exhaust gas temperature sensor 17 and the catalyst temperature sensor 18.

FIG. 2 is a block diagram schematically showing the fuel injection control in the control unit 8. As shown in FIG. This embodiment has a configuration in which a transient correction operation unit is added to the configuration of the related art as shown in FIG. That is, in this transient correction calculation unit, the catalyst temperature, the intake air amount,
A delay (ratio) of an actual value of each parameter such as an EGR rate, a rail pressure, and a catalyst temperature (exhaust gas temperature) with respect to a target value is calculated. Then, the main injection timing, the pilot injection timing, and the pilot injection amount are corrected and controlled based on these ratios.

Each map shown in FIG. 2 is individually prepared corresponding to each of the main injection timing, the pilot injection timing, and the pilot injection amount, as in the above-described prior art.
As an example, each map for main injection timing setting is shown in FIGS.

Next, a specific control flow executed in the control unit 8 will be described with reference to a flowchart.

FIG. 8 is a flowchart for setting the main injection timing. First, at step 101, in addition to the fuel injection amount Qf, the engine speeds Ne,
Engine cooling water temperature Tw, intake air amount Qac, exhaust temperature T
exh, the catalyst temperature Tcat is read. The fuel injection amount Qf is calculated based on the accelerator opening detected by the accelerator opening sensor 13 and the engine speed Ne.

In step 102, the engine speed Ne
The basic main injection timing TMIT is calculated by referring to the basic map shown in FIG. 3 based on the fuel injection amount Qf.

In step 103, the engine speed Ne
Based on the fuel injection amount Qf and the water temperature correction map shown in FIG.
By calculating MHhos (MIT) and referring to the water temperature correction coefficient map shown in FIG. 5 based on the engine cooling water temperature Tw, the water temperature correction coefficient TH for the main injection timing is obtained.
hos (MIT) is calculated.

In step 104, the above water temperature correction amount T
MHhos (MIT) and water temperature correction coefficient THhos (MI
T), the basic correction amount TMhos of the main injection timing
(MIT) is calculated.

In step 105, the ratio RTcat of the actual value to the target value of the catalyst temperature, in step 106, the ratio RQac of the actual value to the target value of the intake air amount, and in step 107, the ratio of the actual value to the target value of the EGR rate. REGR
In step 108, the ratio RPrail of the actual value to the target value of the rail pressure is calculated. The calculation processing of steps 105 to 108 will be described later.

In step 109, steps 105-1
08, all ratios RTcat, RQac, REG
A transient correction value RHos is calculated based on R and RPrail. Specifically, the transient correction value Rhos is obtained from the following equation.

[0039]

Rhos = RTcat × RQac × RPrai
1 / REGR When the transient correction value Rhos is greater than 1, the main injection timing is retarded. When the transient correction value Rhos is less than 1, the main injection timing is advanced. Similarly, in the flowcharts of FIGS. 9 and 10 described later, when the transient correction value Rhos is larger than 1, the pilot injection timing is retarded, the pilot injection amount is reduced, and when the transient correction value Rhos is smaller than 1, pilot injection is performed. The timing is advanced, and the pilot injection amount is increased.

In step 110, the engine speed Ne
The transient correction amount HFhos of the main injection timing is referred to by referring to the map shown in FIG.
(MIT) is calculated. Further, based on the transient correction value RHos obtained in step 109, a transient correction coefficient Hho of the main injection timing is obtained by referring to a map shown in FIG.
s (MIT) is obtained.

In order to create the transient correction amount map shown in FIG. 6, steady running is performed at optimum MIT, PIT, and PQf during steady operation, and step response is performed for each parameter of the intake air amount, the EGR rate, and the rail pressure. The condition is set in consideration of the emission at that time, and the optimum injection timing and injection amount at that time are adapted. Here, regarding the catalyst temperature (exhaust gas temperature), it is necessary to see the sensitivity to the exhaust gas temperature at each of the main injection timing, the pilot injection timing, and the pilot injection amount at the representative acceleration point at a low temperature.

In step 111, the final correction value TMH (MIT) of the main injection timing is calculated from TMhos (MIT) obtained in step 104 and HFhos (MIT) and Hhos (MIT) obtained in step 110. I do.

In step 112, the basic main injection timing TM
A final injection value TMITF of the main injection timing is calculated by adding the final correction value TMH (MIT) of the main injection timing to IT.

In the same manner as the setting of the main injection timing, the pilot injection timing and the pilot injection amount are set. That is, the pilot injection timing and the pilot injection amount are set with reference to the pilot injection timing or pilot injection amount map prepared in advance as in FIGS.

FIG. 9 is a flowchart for setting the pilot injection timing. Only the parts different from FIG. 8 will be described. In step 202, the basic pilot injection timing TPIT is calculated with reference to the pilot injection timing basic map. In step 203, the water temperature correction amount TMHhos (PIT) is calculated with reference to the water temperature correction map, and the water temperature correction coefficient TH is calculated with reference to the water temperature correction coefficient map.
compute hos (PIT). In step 204, the water temperature correction amount TMHhos (PIT) and the water temperature correction coefficient TH
hos (PIT) to basic correction amount TMhos (PIT)
Is calculated. In step 210, the transient correction coefficient Hhos (PIT) is calculated with reference to the transient correction coefficient map, and the transient correction amount HFh is determined with reference to the transient correction map.
os (PIT) is calculated. In step 211, the final correction value TMH (PIT) is calculated, and in step 212, the final command value TPITF of the pilot injection timing is calculated.

FIG. 10 is a flowchart for setting the pilot injection amount, and only the parts different from FIG. 8 will be described. In step 302, the basic pilot injection amount TPQf is calculated with reference to the basic map. In step 303, the water temperature correction amount TMHhos is referred to with reference to the water temperature correction map.
(PQf) is calculated, and a water temperature correction coefficient THhos (PQf) is calculated with reference to a water temperature correction coefficient map. In step 304, the basic correction amount TMhos based on TMHos (PQf) and THhos (PQf).
(PQf) is calculated. In step 310, the transient correction coefficient Hhos (PQf) is referenced with reference to the transient correction coefficient map.
And the transient correction amount HFhos (PQf) is calculated with reference to the transient correction map. Step 311
Then, the final correction value TMH (PQf) is calculated. In step 312, the final command value TPQfF of the pilot injection amount is calculated.
Is calculated.

FIG. 11 is a subroutine for calculating the ratio RTcat of the actual value to the target value of the catalyst temperature, and this routine is executed in steps 105, 205, and 305 in FIGS.

In step 21, the target catalyst temperature MTcat is calculated based on the engine speed Ne and the fuel injection amount Qf by referring to a map shown in FIG. In step 22, the correction amount HFTcat of the target catalyst temperature is calculated by referring to the map shown in FIG. 13 based on the engine speed Ne and the fuel injection amount Qf, and shown in FIG. 14 based on the engine cooling water temperature Tw. The correction coefficient HTcat of the target catalyst temperature is calculated by referring to the map. In step 23, the final correction amount HMTcat of the target catalyst temperature is calculated based on HFTcat and HTcat obtained in step 22. In step 24, the final correction amount HMTcat is added to the target catalyst temperature MTcat to obtain the final target catalyst temperature TMcat.
Calculate Tcat. In step 25, the ratio R of the actual value Tcat to the final target value TMTcat of the catalyst temperature
Calculate Tcat.

FIG. 15 is a subroutine for calculating the ratio RQac of the actual value to the target value of the intake air amount. This routine is performed in steps 106, 206 and 306 of FIGS.
Executed in

In step 31, a target intake air amount MQac is calculated based on the engine speed Ne and the fuel injection amount Qf by referring to a map shown in FIG. In step 32, the correction amount HFQac of the target intake air amount is calculated by referring to the map shown in FIG. 17 based on the engine speed Ne and the fuel injection amount Qf, and based on the engine cooling water temperature Tw, FIG. The correction coefficient HQac of the target intake air amount is calculated by referring to the map shown. In step 33, a final correction amount HMQac of the target intake air amount is calculated based on HFQac and HQac obtained in step 32. In step 34, the final correction amount H is added to the target intake air amount MQac.
MQac is added to calculate a final target intake air amount TMQac. In step 35, a ratio RQac of the actual value Qac to the final target value TMQac of the intake air amount is calculated.

FIG. 19 is a subroutine for calculating the ratio REGR of the actual value to the target value of the EGR rate, and this routine is executed in steps 107, 207, and 307 of FIGS.

In step 41, the target EGR rate MEGR is calculated based on the engine speed Ne and the fuel injection amount Qf by referring to a map shown in FIG.
In step 42, the correction amount HFEGR of the target EGR rate is calculated by referring to the map shown in FIG. 21 based on the engine speed Ne and the fuel injection amount Qf, and shown in FIG. 22 based on the engine coolant temperature Tw. By referring to the map, the correction coefficient HE of the target EGR rate is obtained.
Calculate GR. In step 43, based on the HFEGR and HEGR obtained in step 42, the target EGR
The final correction amount HMEGR of the ratio is calculated. In step 44, the final target EGR rate TMEGR is calculated by adding the final correction amount HMEGR to the target EGR rate MEGR. In step 45, the ratio REGR of the actual value EGR to the final target value TMEGR of the EGR rate is calculated.

FIG. 23 is a subroutine for calculating the ratio RPrail of the actual value to the target value of the rail pressure. This routine is performed in steps 108, 208 and 30 of FIGS.
8 is performed.

In step 51, the target rail pressure MPrail is calculated based on the engine speed Ne and the fuel injection amount Qf by referring to a map shown in FIG. In step 52, the correction amount HFPrail of the target rail pressure is calculated by referring to the map shown in FIG. 25 based on the engine speed Ne and the fuel injection amount Qf, and shown in FIG. 26 based on the engine coolant temperature Tw. By referring to the map, the correction coefficient HPrail of the target rail pressure is calculated. In a step 53, a final correction amount HMPrail of the target rail pressure is calculated based on the HFPrail and the HPrail obtained in the step 52. In step 54, the target rail pressure MPrai
The final correction amount HMPrail is added to 1 to calculate the final target rail pressure TMPrail. In step 55,
The ratio RPrail of the actual value Prail to the final target value TMPrail of the rail pressure is calculated.

As described above, in the present embodiment, each of the parameters that change according to the operating state of the engine and affect the combustion state, that is, the intake air amount, the EGR rate, the rail pressure, and the catalyst temperature (exhaust temperature) are described. , A delay (ratio) of an actual value with respect to a target value is calculated, and the main injection timing, the pilot injection timing, and the pilot injection amount are corrected and controlled based on these ratios. Therefore, it is possible to reliably prevent an increase in emission, fuel consumption, and combustion noise at the time of transient operation due to a parameter delay, and to improve engine operation performance such as ignitability.

[Brief description of the drawings]

FIG. 1 is a configuration explanatory view showing a fuel injection control device for a diesel engine according to an embodiment of the present invention.

FIG. 2 is a functional block diagram of fuel injection control according to the embodiment.

FIG. 3 is a basic map for setting a main injection timing.

FIG. 4 is a water temperature correction map for setting a main injection timing.

FIG. 5 is a water temperature correction coefficient map for setting a main injection timing.

FIG. 6 is a transient correction amount map for setting a main injection timing.

FIG. 7 is a transient correction coefficient map for setting a main injection timing.

FIG. 8 is a flowchart for setting a main injection timing.

FIG. 9 is a flowchart for setting a pilot injection timing.

FIG. 10 is a flowchart for setting a pilot injection amount.

FIG. 11 is a subroutine for setting a ratio of an actual value to a target value of a catalyst temperature.

FIG. 12 is a map for setting a target catalyst temperature.

FIG. 13 is a map for setting a correction amount of a target catalyst temperature.

FIG. 14 is a map for setting a correction coefficient of a target catalyst temperature.

FIG. 15 is a subroutine for setting a ratio of an actual value to a target value of the intake air amount.

FIG. 16 is a map for setting a target intake air amount.

FIG. 17 is a map for setting a correction amount of a target intake air amount.

FIG. 18 is a map for setting a correction coefficient of a target intake air amount.

FIG. 19 is a subroutine for setting a ratio of an actual value to a target value of the EGR rate.

FIG. 20 is a map for setting a target EGR rate.

FIG. 21 is a map for setting a correction amount of a target EGR rate.

FIG. 22 is a map for setting a correction coefficient of a target EGR rate.

FIG. 23 is a subroutine for setting a ratio of an actual value to a target value of the rail pressure.

FIG. 24 is a map for setting a target rail pressure.

FIG. 25 is a map for setting a correction amount of a target rail pressure.

FIG. 26 is a map for setting a correction coefficient of a target rail pressure.

FIG. 27 is a functional block diagram of fuel injection control according to a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Engine main body 3 ... Air flow meter 6 ... Common rail 8 ... Control unit 12 ... EGR valve 14 ... Rail pressure sensor 16 ... Catalyst 17 ... Exhaust temperature sensor 18 ... Catalyst temperature sensor

Claims (6)

[Claims] 1. A fuel injection control device for a diesel engine capable of performing a pilot injection before a main fuel injection, wherein a real value of at least one parameter that changes according to an engine operating state and affects a combustion state. And a means for setting a target value of the parameter. In a transient operation, the main injection timing, the pilot injection timing, and the pilot injection amount are determined based on a delay of an actual value with respect to the target value of the parameter. A fuel injection control device for a diesel engine, wherein at least one is corrected. 2. The method according to claim 1, wherein the parameter includes an intake air amount, and at least one of a main injection timing, a pilot injection timing, and a pilot injection amount is corrected based on a ratio of an actual value of the intake air amount to a target value. The fuel injection control device for a diesel engine according to claim 1, wherein: 3. The method according to claim 2, wherein the parameter includes an EGR rate, and at least one of a main injection timing, a pilot injection timing, and a pilot injection amount is corrected based on a ratio of an actual value to a target value of the EGR rate. Claim 1 or 2
3. A fuel injection control device for a diesel engine according to claim 1. 4. A fuel injection device of a common rail type, wherein the parameter includes a rail pressure, and at least a main injection timing, a pilot injection timing and a pilot injection amount are determined based on a ratio of an actual value of the rail pressure to a target value. The fuel injection control device for a diesel engine according to any one of claims 1 to 3, wherein one is corrected. 5. A catalyst is provided in an exhaust passage, wherein the parameter includes an exhaust temperature or a catalyst temperature, and a main injection timing, a pilot injection timing, and a pilot injection timing are determined based on a ratio of an actual value of the exhaust temperature or the catalyst temperature to a target value. The fuel injection control device for a diesel engine according to any one of claims 1 to 4, wherein at least one of the pilot injection amounts is corrected. 6. A transient correction value is calculated based on a ratio of an actual value to a target value of the parameter, and at least one of a main injection timing, a pilot injection timing, and a pilot injection amount is corrected based on the transient correction value. If the transient correction value is greater than 1, the main injection timing is retarded, the pilot injection timing is retarded, or the pilot injection amount is reduced, and if the transient correction value is less than 1,
6. The fuel injection control device for a diesel engine according to claim 2, wherein the main injection timing is advanced, the pilot injection timing is advanced, or the pilot injection amount is increased.