JPS62240450A - Fuel injection controller for diesel engine - Google Patents

Abstract

PURPOSE:To always permit the pilot injection in an optimum quantity by increase-correcting the pilot-jetted fuel by a prescribed quantity by a correcting means according to the increase of the detected exhaust circulation quantity, in the pilot injection in an exhaust recirculation type Diesel engine. CONSTITUTION:When the fuel in the quantity obtained according to the operation state of an engine M1 which is detected by an operation state detecting means M2 is jetted from a fuel injection means M3, a prescribed quantity is pilot-jetted, and after the lapse of a prescribed time, main injection is carried out. Further, the exhaust in the quantity corresponding to the detected operation state is allowed to recirculate into the intake air of the engine M1 by an exhaust circulation means M4. Further, a circulation quantity detecting means M5 for detecting the circulation quantity of the exhaust is installed, and the pilot injection quantity is increase-corrected by a correcting means M6 according to the increase of the detected circulation quantity. Therefore, the exhaust characteristic can be improved, and combustion noise can be reduced.

Description

Detailed Description of the Invention Object of the Invention [Field of Industrial Application] The present invention relates to a fuel injection control device for a deep-pillar engine that effectively injects fuel into a pilot 1 prior to main injection during fuel injection during exhaust gas recirculation. .

[Prior Art] - Conventionally, various fuel injection control devices have been developed for the purpose of reducing diesel engine combustion noise. For example, prior to injecting an amount of fuel that is determined according to the operating state of the DIPIL engine (hereinafter simply referred to as main injection),
A fuel injection control device that injects a small amount of fuel (hereinafter simply referred to as pilot injection) has been proposed. These devices achieve efficient combustion in a diesel engine through pyrower 1 injection, and reduce combustion noise by controlling combustion slowly, particularly during light loads, to prevent diesel knock. In such a device, the base of the fuel injected during the pilot injection is always set to be a predetermined constant value.

By the way, in recent years, in order to avoid harmful components in exhaust gas,
A portion of the exhaust gas is returned to the intake air depending on the operating conditions.

Diesel engines are also known which are configured with so-called exhaust gas recirculation.

[Problems to be Solved by the Invention] This conventional technology has the following problems. In other words, when performing pilot injection in the above-mentioned exhaust gas recirculation type diesel engine, if the amount of exhaust gas circulation is large, it is necessary to set a larger amount of fuel to be injected during pilot injection than when the amount of circulation is small. be. This is because if the circulation of exhaust gas is large, the heat capacity of the air taken into the combustion chamber increases, resulting in a decrease in ignitability and combustion speed.

For this reason, if the configuration is such that a constant amount of pilot injection is always performed, when the amount of exhaust gas circulation is large, pi[:
There are cases where the amount of injection in a single injection becomes relatively small, resulting in a phenomenon in which ignition does not occur or even if ignition occurs, the flame goes out quickly. Therefore, the main injection is performed after the spark caused by the pilot injection is extinguished, so there is a problem that the effect of the pilot injection is not produced and combustion noise cannot be reduced.

SUMMARY OF THE INVENTION An object of the present invention is to provide a fuel injection control device for a deep-pillar engine that performs pilot injection in a suitable amount corresponding to the amount of exhaust gas circulation.

Structure of the Invention [Means for Solving the Problems] The present invention, which has been made to solve the above problems, as illustrated in FIG. , a fuel injection means M3 that, when injecting fuel of a color corresponding to the detected operating state to the deep-pil engine M1, first performs a pilot injection to inject a predetermined amount, and then performs a main injection after a predetermined period of time has elapsed; A fuel injection control device for a diesel engine, further comprising an exhaust circulation means M4 that recirculates an amount of the exhaust gas of the diesel engine M1 according to the detected operating state to the intake air of the diesel engine M1, further comprising: Circulation amount detection means M for detecting the circulation amount
5, and a correction means M6 for increasing the amount of pilot injection for a predetermined period in response to the detected increase in the amount of circulation. be.

The operating state detection means M2 is for detecting the operating state of the diesel engine M1. For example, Deepill Agency M
1, a rotation speed sensor that detects the rotation speed of the diesel engine M1, and the like.

The fuel injection means M3 performs a pilot injection of a predetermined amount first, and then performs a main injection after a predetermined period of time when injecting fuel according to the operating state. For example, the fuel injection pump may be provided with a spill electromagnetic control valve that communicates with and shuts off the high-pressure chamber and low-pressure chamber of the fuel injection pump. In addition, instead of an electromagnetic control valve for spill, an actuator using a piezoelectric element (for example, PZT, etc.)
It is also possible to configure the engine to perform the pyrower 1 injection and the main injection. When configured in this way, there is an advantage that the response speed is improved.

The exhaust gas circulation means M4 is for recirculating exhaust gas. For example, a recirculation pipe that recirculates exhaust gas from the exhaust system of diesel engine M1 to the intake system, a flow rate control valve that is interposed in the recirculation pipe and changes the cross-sectional area of the recirculation pipe to change the amount of circulating exhaust gas, and its control equipment. and the above-mentioned diesel engine M1
The exhaust gas can be configured to be recirculated by the action of the control device according to the operating state of the exhaust gas.

The circulation amount detection means M5 is for detecting the circulation amount of exhaust gas. For example, when the flow rate control valve that changes the circulation amount is a solenoid valve, this can be realized by detecting the excitation current value of the flow rate control valve or the energization time ratio of the excitation current. Further, for example, it may be configured to measure the opening degree of a flow rate control valve. Further, for example, it may be a sensor that measures the exhaust flow m in the exhaust gas recirculation pipe.

The correction means M6 is for increasing a predetermined amount of pilot-injected fuel in response to an increase in the amount of exhaust gas circulation. For example, it can be realized by a discrete logic circuit. Alternatively, it may be configured as a logic operation circuit together with a well-known CPU, ROM, RAM, and other peripheral circuit elements, and perform the above-mentioned increase according to a predetermined processing procedure.

[Function] The fuel injection control device I for a diesel engine according to the present invention has a first
As illustrated in the figure, among the fuels I according to the operating state of the diesel engine M1 detected by the operating state detecting means M2,
The fuel injection means M3 first injects a predetermined amount as a pilot, and then performs the main injection after a predetermined period of time has elapsed, and the exhaust circulation means M4 detects the amount of circulation when recirculating the amount of exhaust gas according to the above-mentioned operating conditions to the intake air. In response to the increase in the circulating amount of exhaust gas detected by the means M5, the correcting means M6 operates to increase the predetermined amounts of the pyrowers 1 to 1 to 3.

In other words, when the combustion characteristics deteriorate due to an increase in the amount of exhaust gas circulation, the amount of pyro injection/injection mother is increased to stabilize combustion.

Therefore, the fuel injection control device for a diesel engine of the present invention has the following features:
It works to pilot inject an appropriate amount of fuel corresponding to the circulation of the exhaust gas of the diesel engine M1. The technical problems of the present invention are solved by each component of the present invention acting as described above.

[Example] Next, a preferred example of the present invention will be described in detail based on the drawings.

FIG. 2 is a system configuration diagram of a diesel engine equipped with a diesel engine fuel injection control device according to an embodiment of the present invention. Power is transmitted from a four-cycle diesel engine 1 to a Bosch distribution type fuel injection pump 2 via a drive shaft 3 connected to a crankshaft (not shown). The drive shaft 3 includes a vane pump 4 which is a fuel feed pump, and a pulser 5 having a plurality of protrusions at equal intervals on the outer circumferential surface.
, and coupling 6 are connected. Fuel supplied from a fuel tank (not shown) is sucked in from a fuel supply port 7 by a vane pump 4, and is filled into a fuel chamber 8. The pressure of the fuel is regulated by a regulating valve 9, and excess fuel is returned to a fuel tank (not shown) via a fuel return port 10.

The coupling 6 is connected to one end of a plunger 12 which is essentially connected to the cam plate 11, and the other end of the plunger 12 is fitted into the cylinder 13.

The coupling 6 and the plunger 12 rotate together, and the plunger 12 is supported so as to be able to reciprocate in its axial direction, that is, in the directions indicated by arrows A and B in FIG. The plunger 12 and the cam plate 11 are urged by a spring 14 in the direction indicated by arrow A in the figure.

A roller ring 15 is disposed between the coupling 6 and the cam plate 11. The roller ring 15
On the surface facing the cam plays 1 to 11, a cam roller 16 is arranged along the circumference around the rotation axis of the roller ring 15.
is installed.

Furthermore, protrusions 11a are provided on the surfaces of the cam plays 1 to 11 facing the roller ring 15.

The drive shaft 3 connects the cam play 1- through the coupling 6.
The rotational force is transmitted to the plunger 11, and the cam plate 11 pressed against the roller ring 15 rotates, so that the plunger 1
2 rotates and reciprocates in the directions indicated by arrows A and B in FIG. 2 to distribute and pressure feed fuel as described below.

A block 18 is attached to the housing 17 of the fuel injection pump 2 by fitting the cylinder 13 thereto. A fuel passage 19 is provided within the block 18 and communicates with the fuel chamber 8 on the low pressure side within the housing 17 . The fuel passage 19 is communicated or cut off by a fuel cutoff valve 20, which is a solenoid valve. Furthermore, a fuel control valve 21, which is a solenoid valve for performing pilot injection and main injection, is attached to the block 18. A needle valve 22 is disposed in the fuel control valve 21, and a high pressure chamber 23 is formed by the twenty-one dollar valve 22, the plunger 12 and the cylinder 13 described above. The high pressure chamber 23 includes fuel introduction recesses 24 formed on the outer peripheral surface of the plunger 12 in correspondence with the number of cylinders.
It can communicate with a fuel introduction passage 25 between the fuel cutoff valve 20 and the high pressure chamber 23 via the fuel cutoff valve 20 and the high pressure chamber 23 . A return passage 26 of the fuel control valve 21 is communicated with the fuel introduction passage 25 via a communication passage 27 within the cylinder 13 . In addition, block 18
A delivery valve 28 is disposed therein, and can communicate with the high pressure chamber 23 via a fuel supply passage 29 and fuel supply recesses 30 formed on the outer peripheral surface of the plunger 12 in correspondence with the number of cylinders.

The fuel injection pump 2 configured as described above operates as follows. When the drive shaft 3 rotates in synchronization with the rotation of the diesel engine 1, the vane pump 4 is driven.
The fuel whose pressure is regulated by the pressure regulating valve 9 is transferred to the fuel chamber 8 and the fuel passage 1.
and is supplied to the fuel introduction passage 25. Meanwhile, the plunger 12 and the cam plate 11 rotate in synchronization with the rotation of the drive shaft 3. At this time, the protrusion 1 of the cam plate 11
1 a 1): CI-cylinder 15 cam roller 16
In the process of riding on the cam roller 16, the plunger 12 shifts to a fuel compression stroke, and in the process of the protrusion 11a riding down on the cam roller 16, the plunger 12 shifts to a fuel suction stroke.

During the suction stroke of the plunger 12, the fuel cutoff valve 20 is energized and one fuel passage is communicated, so that the fuel flows through the fuel passage 19.
, is introduced into the high pressure chamber 23 via the fuel introduction passage 25 and the fuel introduction recess 24.

On the other hand, during the compression stroke of the plunger 12, the fuel control valve 21
Only while the needle valve 22 is energized and the through hole 22a is blocked, the fuel in the high pressure chamber 23 is compressed and is forcefully delivered to the delivery valve 28 via the fuel supply recess 30 and the fuel supply passage 29.

When the power supply to the fuel control valve 21 is stopped, the needle valve 22 moves in the direction shown by arrow B in FIG. , and the pressure feeding of the fuel 11 is completed. Note that the delivery valve 28 of the fuel injection pump 2 is connected to the injection nozzle 32 of each cylinder of the diesel engine 1 via a fuel pipe 31.

The diesel engine 1 includes a cylinder 33 and a piston 34.
and the cylinder head 33b form a main combustion chamber 35, a sub-combustion chamber 36 is connected to the main combustion chamber 35, and the injection nozzle 32 described above injects fuel into the sub-combustion chamber 36. Further, a compressor 39 of a turbocharger 38 is disposed in the intake pipe 37 of the diesel engine 1, while a turbine 41 of a turbocharger 7-gear 38 is disposed in the exhaust pipe 40. Further, the exhaust pipe 40 is also provided with a waste gate valve 42 that adjusts the supercharging pressure.

Further, the diesel engine 1 has an intake port 37a that communicates a part of the exhaust gas from the exhaust pipe 40 to the intake pipe 37.
The recirculation pipe 43 has an exhaust gas recirculation valve (hereinafter simply EGRV) that adjusts the circulation amount of exhaust gas.
) 44 is interposed. The EGRV 44 has a diaphragm chamber, and the diaphragm chamber is connected to a vacuum pump 46 via a pressure control valve 45. Pressure control valve 4
When 5 is excited at a predetermined duty ratio, the vacuum pump 46
Adjust the negative pressure generated in to the negative pressure according to the duty ratio.
F, the regulated negative pressure is introduced into the diaphragm chamber of the EGRV 44. Therefore, the EGRV 44 opens to an opening degree corresponding to the pressure difference between the negative pressure and atmospheric pressure. Therefore, the main exhaust gas determined by the opening degree is recirculated from the exhaust pipe 40 to the intake port 37.a. In this way, the amount of circulation of exhaust gas is determined by the drive duty ratio of the pressure control valve 45.

Note that if the pressure control valve 45 is not excited,
The EGRV 44 is closed by the bias of a spring disposed within the diaphragm chamber of the EGRV 44. Therefore, the circulation of exhaust gas is interrupted.

As a detector, the pulser 5 of the fuel injection pump 2 mentioned above is used.
A rotational speed sensor 50 consisting of an electromagnetic pickup arranged opposite to the outer peripheral surface of the engine, an accelerator sensor 51 consisting of a potentiometer for detecting the amount of accelerator operation, and an accelerator sensor 51 installed in the intake pipe 37 of the Deep Pill engine 1 to detect the intake air temperature. a supercharging pressure sensor 53 installed in the intake port 37a communicating with the intake pipe 37 to detect the boost pressure, and a water temperature sensor 54 installed in the cylinder block 33a to detect the cooling water temperature. , there is a crank angle sensor 56 that closely opposes a signal disk plate provided on a crankshaft (not shown).

The detection signals of each of the above sensors are transmitted by the electronic control unit (hereinafter simply E).
On the other hand, the ECU 60 controls the diesel engine 1 by driving the fuel cutoff valve 20, fuel control valve 21, and pressure control valve 45 described above.

Next, the configuration of the ECU 60 will be explained based on FIG. 3.

The ECU 60 inputs and calculates each signal detected by each sensor described above according to a control program, and also includes a central processing unit (hereinafter simply referred to as CPU) 6 that performs processing for controlling the multiple valves.
0a, a read-only memory (hereinafter simply referred to as ROM) 60b in which the above control program and initial data are stored in advance, and a random access memory in which various data input to the ECU 60 and data necessary for arithmetic control are temporarily stored. (hereinafter simply referred to as RAM) 60c and the key switch of diesel engine 1 are turned off by the driver.
As a logical operation circuit mainly including a backup random access memory (hereinafter simply referred to as backup RAM) 60d backed up by a battery so that various data necessary for controlling the diesel engine 1 can be stored and retained even if the diesel engine 1 is F. It is connected to an input port 0f and an output port 0g via a common bus 60e to perform input/output with external devices.

The ECU 60 also includes the above-mentioned accelerator sensor 51.
, water temperature sensor 54, intake temperature sensor 52, boost pressure sensor 5
Buffer of output signal from 3'60t1゜60i,60
60k are provided, and the output signals of each of the above sensors are sent to the CPU 60a1. : A multiplexer 60n that selectively outputs four signals, and an A/D converter 60p1 that converts an analog signal into a digital signal; a rotation speed sensor 50;
A waveform shaping circuit 60q for shaping the waveform of the output signal of the crank angle sensor 56 is also provided. Signals from each of these sensors are input to the CPU 60a via an input port 0f.

Furthermore, the ECU 60 includes drive circuits 60r and 60s for the fuel cutoff valve 20, fuel control valve 21, and pressure control valve 45, which have already been described.
, 60t, and the CPU 60a connects to each of the above drive circuits 60r via an output port 0q.

A control signal is output at 60s and 60t.

Next, the processing executed by the ECU 60 is shown in FIG.
This will be explained based on the flowcharts shown in FIGS. 6 and 9.

The exhaust gas recirculation amount calculation process shown in FIG. 4 is repeatedly executed at predetermined time intervals as the diesel engine 1 is started. First, in step 100, the water temperature sensor 54 detects the cooling water temperature TW. In the following step 110, it is determined whether the cooling water temperature T W lfi is equal to or higher than the set temperature TW1, and if the determination is made in the front window, the process proceeds to step 120. In step 120, a process is performed to calculate the drive duty ratio ED of the pressure control valve 45 in order to perform exhaust gas recirculation. Here, there is a relationship as shown in FIG. 5 between the accelerator operation ff1Vh, the engine rotational speed Ne, and the drive duty ratio ED. The ECU 60 stores a map as shown in FIG. 5 in the ROM 60b in advance, and after calculating the drive duty ratio ED based on the accelerator operation amount vh and the engine rotational speed Ne according to the map, the ECU 60 temporarily starts the main exhaust The recirculation m calculation process ends. On the other hand, if it is determined in step 110 that the cooling water temperature TW is less than the set temperature TW1, the process proceeds to step 130 since exhaust gas recirculation is not performed, and after setting the drive duty ratio ED to the value O(,: The main exhaust gas recirculation m calculation process ends.Thereafter, the main exhaust gas recirculation m calculation process is repeatedly executed at predetermined intervals.

Next, the fuel injection m calculation process will be explained based on the flowchart of FIG. This twisting material injection IJffl calculation process is repeatedly executed at predetermined time intervals as the diesel engine 1 is started. First, in step 2OO, the basic pilot injection energization time DPS is calculated. This basic pyrower 1-injection energization time DPS is defined as shown in FIG. 7 using engine rotational speed Ne and load as both variables. The ECU 60 prepares a map as shown in FIG. 7 in advance.
It is stored in a predetermined area in the OM 60b, and the basic pilot injection energization time DPS is calculated from the above map based on the output signals from the rotational speed center 50 and the accelerator sensor 51. In the subsequent step 210, a process is performed in which the drive duty ratio ED of the pressure control valve 45 obtained in the above-mentioned exhaust gas recirculation amount calculation process is read from the RAM 60C. Next, the process proceeds to step 220, where processing for calculating the pilot injection energization correction time ΔDPED is performed. here,
There is a relationship as shown in FIG. 8 between the pilot injection energization correction time ΔDPED and the drive duty ratio ED of the pressure control valve 45. That is, as the drive duty ratio ED increases (the circulation amount increases), the pilot injection energization correction time ΔDPED is extended. ECLI60 is pre-RO
A map as shown in FIG. 8 is stored in the M60b, and according to the map, the pilot injection energization correction time ΔDPED is calculated based on the value of the drive duty ratio ED.

In the following step 230, the basic pilot injection energization time DPS obtained in the step 200 is applied in the step 22.
A process is performed to calculate the pilot injection energization time DP by adding the pilot injection energization correction time ΔDPED obtained in 0.

Next, the process proceeds to step 240, where the basic injection amount QS of the main injection is calculated based on the rotational speed Ne of the deep pill engine 1 and the accelerator operation amount vh from a map that defines the relationship between the three. In the subsequent step 250, based on the output signal of the boost pressure sensor 53, a pressure correction process is performed to increase the amount of the basic injection gFImQs calculated in the step 240 as the pressure increases, and the actual main injection mQ is calculated.

Finally, the process proceeds to step 260, where tn is input when the main injection is energized based on the engine rotational speed Ne and the actual main injection fJJmo. Note that the pressure correction process is performed using correction data defined in a predetermined map. After executing step 260, the process proceeds to NEXT and the main fuel injection amount calculation process is temporarily ended. Thereafter, this fuel injection amount calculation process is repeatedly executed at predetermined time intervals.

Next, the fuel injection process will be explained based on the flowchart shown in FIG. This fuel injection process is performed every time the crank angle sensor 56 detects a reference position signal indicating that the piston of the diesel engine 1 is at a predetermined position before top dead center. L Executes without a hitch. First, in step 300, it is determined whether or not the pilot injection start time has arrived, and the system waits until the time arrives. This determination is made by inputting an interrupt signal to the CPU 60a when the time set in advance in the conveyor A register in the output port 0g matches the time counted by the counter. When the pilot injection start time arrives, the process proceeds to step 310, and pilot injection is started. The pilot injection is performed in step 23 above.
This is performed by energizing the fuel control valve 21 until the pilot injection energization time DP calculated in step 0 has elapsed (step 320). Pilot injection energization time DP
When the time period has elapsed, the energization of the fuel control valve 21 is stopped and the pilot injection ends (step 330). In the following step 340, it is determined whether or not the main injection start time has arrived, and the process waits until the main injection start time has arrived. This determination is made by inputting an interrupt signal to the CPU 60a when the time set in advance in the conveyor B register in the output port 0g matches the time counted by the counter. When the main injection start time is reached, the process proceeds to step 350.
, and main injection begins. The main injection is performed by energizing the fuel control valve 21 until the main injection energization time tn calculated in step 260 has elapsed (step 360).

When the main injection energization time tn has elapsed, the energization to the fuel control valve 21 is stopped and the main injection ends 21 (step 370).
). Thereafter, this fuel injection process is repeatedly executed every time the crank angle sensor 56 detects the reference signal.

Next, an example of the control timing of the above process will be explained based on the timing chart shown in FIG. 10. As mentioned above, after the reference position signal is detected by the crank angle sensor 56, the time T1, which is the pilot injection start time, is reached.
At this point, the drive signal for the fuel control valve 21 is turned ON and pilot injection is started. This pilot injection is carried out over a period of time D P, and at time T2 the drive signal is switched to O.
It becomes FF and ends. Note that the time DP is determined by the pilot injection energization correction based on the drive duty ratio ED of the pressure control valve 45 in the basic pilot injection energization time DPS, which is determined based on the accelerator operation of the Deep Pill engine 1, Jyh, and the rotational speed Ire, as described above. This is the time obtained by adding the time ΔDPED. During this time DP, the plunger 12 is in a compression stroke, and an amount of fuel corresponding to the plunger lift amount is pilot injected. The pilot-injected fuel ignites at time T3. Thereafter, at time T4, when time τ has elapsed from time T1, the fuel control valve 21
The drive signal is turned ON and main injection is started. Since the main injection is performed after the fuel injected from the above-mentioned pylob 1 is ignited, smooth combustion is achieved. According to the already calculated main injection energization time tn, the drive signal for the fuel control valve 21 is turned off at time T5, and the main injection ends.

During this time, the plunger 12 is in the compression stroke, and fuel corresponding to the lift amount of the plunger A7 is main injected. Note that the sum of the pyro injection amount and the main injection amount is set to be the optimal fuel injection amount for the operating condition of the diesel engine 1.

Thereafter, pilot injection and main injection are alternately and repeatedly executed in the order shown in (a) above.

In this embodiment, the diesel engine 1 corresponds to the diesel engine M1, the rotational speed sensor 9''50 and the accelerator sensor 51 correspond to the operating state detection means M2, and the fuel injection pump 2, the ECU 60, and the processing executed by the ECU 60 correspond to the diesel engine M1. (Step 300゜310.320,330,34
0,350,360.370> as the fuel injection means M3, and the recirculation pipe 43, EGRV44, pressure control valve 45, vacuum pump 146, ECU 60, and the process (step 120) executed by the ECU 60 as the exhaust circulation means M4. Function. Further, in addition to the ECU 60 and the processing executed by the ECU 60, (step 210) functions as a circulation detection means M5, and (steps 220 and 230) function as a correction means M6.

As explained above, in this embodiment, when performing the pilot injection prior to the main injection, the basic pilot injection energization is performed based on the drive duty ratio ED of the pressure control valve 45 that determines the circulation amount of the exhaust gas of the Devil engine 1. The fuel control valve 21 is configured to conduct pilot injection by energizing the fuel control valve 21 over a pilot injection energization time DP obtained by correcting the time DPS. For this reason, especially when the amount of exhaust gas recirculation in the Deep Pill engine 1 is large, the pilot injection amount is increased in response to deterioration of ignitability and combustion characteristics, which improves the reliability of fuel ignition by pilot injection. improves.

In addition, due to the above effects, since the reliability of ignition by pilot injection is high, stable combustion is achieved by the subsequent main injection without any ignition delay, which reduces the combustion noise of diesel engine 1. can be reduced.

Furthermore, since pilot injection and main injection are controlled by driving the fuel control valve 21, control accuracy is improved.

Further, since the pilot injection control and the exhaust gas recirculation control are performed together, it is possible to achieve both noise prevention and improvement of the exhaust characteristics of the diesel engine 1.

Furthermore, in this embodiment, since the exhaust gas circulation LMm is determined from the drive duty ratio ED of the pressure control valve 45, it is possible to detect the circulation I4 base easily and with high accuracy.

However, for example, the flow rate of exhaust gas in the reflux pipe 43 can be adjusted by using a wrench.
It may also be configured to actually measure the amount of circulation.

Although the embodiments of the present invention have been described above, the present invention is not limited to these embodiments in any way, and it goes without saying that it can be implemented in various forms without departing from the gist of the present invention. .

Effects of the Invention As described in detail above, the fuel injection control device for a Dieville engine of the present invention, during pilot injection in an exhaust gas recirculation type diesel engine, responds to an increase in the circulation EMm of the exhaust gas detected by the circulation amount detection means. , the correction means is configured to increase a predetermined amount of pilot injected fuel. Therefore, an excellent effect is achieved in that pilot injection of an optimum amount corresponding to the circulation amount of the exhaust gas of the deep-pillar engine can be performed at all times.

Further, along with the above effects, gentle combustion in the diesel engine is achieved by appropriate pilot injection, so combustion noise can be reduced and the number of images taken can also be reduced.

Furthermore, since exhaust gas recirculation can be performed without impairing the effect of pilot injection, it is possible to achieve both improvement in exhaust characteristic f'l and reduction in engine noise.

[Brief explanation of drawings]

FIG. 1 is a basic configuration diagram conceptually illustrating the contents of the present invention, FIG. 2 is a system configuration diagram of an embodiment of the present invention, and FIG. 3 is for explaining the configuration of the electronic control device. 4 is a flowchart showing the same control, FIG. 5 is a graph showing a map defining the relationship between the accelerator operation, the engine speed, and the drive duty ratio of the pressure control valve. Flow diagram 1-1 also shows the control. Figure 7 is a graph showing the relationship between the load, engine speed, and basic pilot injection energization time. Figure 8 shows the drive duty of the pressure control valve. A graph showing a map defining the relationship between the ratio and the pilot injection energization correction time, FIG. 9 is a flowchart showing the same control, and FIG. 10 is a timing chart showing the control of the pilot injection and main injection. - It is. Ml...Diesel engine M2...Operating state detection means M3...Fuel injection means M4...Exhaust circulation means M5...Circulation amount detection means M6...Correction means 1...Diesel engine 2. ... Fuel II injection pump 43 ... Reflux pipe 44 ... Exhaust gas recirculation valve (EGRV) 45 ... Pressure control valve 46 ... Vacuum pump 50 ... Rotational speed sensor 51 ... Accelerator Sensor 60...Electronic control unit (ECU) 60 a ・CP LJ

Claims (1)

[Scope of Claims] 1. Operating state detection means for detecting the operating state of a diesel engine; and a pilot injection that first injects a predetermined amount of fuel when injecting an amount of fuel corresponding to the detected operating state into the diesel engine. and further includes a fuel injection means for performing main injection after a predetermined period of time has elapsed; and an exhaust circulation means for circulating an amount of exhaust gas from the diesel engine in accordance with the detected operating state into the intake air of the diesel engine. The fuel injection control device for a diesel engine further comprises a circulation amount detection means for detecting the circulation amount of the exhaust gas, and a correction means for increasing the predetermined amount of the pilot injection in response to an increase in the detected circulation amount. A fuel injection control device for a diesel engine, comprising: