JPH06264790A - Fuel injection control device for high pressure injection internal combustion engine - Google Patents

Abstract

(57) [Abstract] [Purpose] Highly accurate fuel injection control is performed by accurately obtaining the difference in the residual fuel amount in the fuel system, regardless of whether it is the rotational range or the direct injection type. [Structure] Fuel is pumped from a fuel injection pump 1 to a fuel injection nozzle 4 provided in a diesel engine 3. The fuel injection nozzle 4 is provided with a pressure sensor 47 for detecting the valve closing pressure. The ECU 71 calculates the residual fuel amount in the fuel system based on the valve closing pressure detected by the pressure sensor 47, and calculates the residual fuel amount deviation. Also, the ECU 71 executes the fuel injection amount control by drivingly controlling the fuel injection pump 1 based on the target injection amount corrected by the residual fuel amount deviation. Therefore, a more appropriate residual fuel amount can be obtained from the valve closing pressure, and thus a more appropriate residual fuel amount deviation can be obtained. Further, in each fuel injection, the influence of the residual fuel amount is more appropriately excluded from the target injection amount, and the fuel injection control is performed without being influenced by the change over time of the fuel injection nozzle 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-pressure injection internal combustion engine equipped with a fuel injection pump, a fuel injection nozzle, etc. The present invention relates to a control device.

[0002]

2. Description of the Related Art Conventionally, as a high pressure injection internal combustion engine equipped with a fuel injection pump, a fuel injection nozzle and the like, a diesel engine, a high pressure gasoline injection type engine and the like can be mentioned.
In this high-pressure injection internal combustion engine, fuel injection control is performed so that the fuel injection amount from the fuel injection nozzle and the fuel injection timing are made to match target target values.

For example, in an electronically controlled diesel engine, fuel in a high pressure chamber is pressure-fed to a fuel injection nozzle and injected into each cylinder of the engine by a lift of a plunger of the fuel injection pump. Then, the spill ring, spill valve, etc. provided in the fuel injection pump are drive-controlled by the actuator so that the fuel injection amount at that time becomes the target injection amount determined according to the operating state of the engine. By this control, the plunger high pressure chamber is opened to the fuel chamber, and a part of the fuel in the plunger high pressure chamber overflows (spills) to the fuel chamber. As a result, the end of pumping of fuel from the fuel injection pump to the fuel injection nozzle, that is, the end timing of fuel injection from the fuel injection nozzle to each cylinder is controlled.

However, even in the electronically controlled diesel engine in which the fuel injection amount control as described above is performed,
The fuel injection nozzle is generally a simple mechanical automatic valve. Since the fuel injection nozzle is a mechanical automatic valve, the actual fuel injection amount from the nozzle may change due to the decrease in valve opening pressure over time. That is, this type of fuel injection nozzle is constructed by incorporating a needle valve and a spring for adjusting the valve opening pressure of the needle valve, and is opened when a fuel pressure of a predetermined level or higher is obtained. Further, the opening pressure of the needle valve is adjusted in advance by a spring so as to have a constant value. Then, when the force of the spring weakens due to a change with time, the valve opening pressure of the needle valve becomes smaller than the initially set pressure. Therefore, in that case, the fuel injection amount from the fuel injection nozzle deviates from the desired target injection amount, which may increase smoke and nitrogen oxide (NOx) emissions from the engine. .

Therefore, a technique for coping with the above problems has been proposed by the applicant of the present invention in Japanese Patent Application No. 4-223084.
No. Gazette proposed. In this conventional technique, highly accurate fuel injection amount control can be stably performed by coping with changes in the valve opening pressure caused by changes over time, manufacturing errors, etc. without providing a special pressure adjusting means in the fuel injection nozzle. Is targeted. Therefore, in this conventional technique, at the start of fuel injection, the valve opening pressure at the time of opening the fuel injection nozzle is measured, and the difference between the measured valve opening pressure and a predetermined reference pressure is taken as the valve opening pressure deviation. Desired. Further, the amount of change in the residual fuel amount in the fuel system from the fuel injection pump to the fuel injection nozzle is obtained based on the valve opening pressure deviation.
Then, the target injection amount for the next fuel injection is corrected based on the change amount of the residual fuel amount. This was done by paying attention to the fact that the difference in valve opening pressure of the fuel injection nozzle has a correlation with the amount of change in the residual fuel amount in the fuel system. This is supported by the fact that the amount of fuel injected from the injection nozzle is changed. Then, here, the fuel injection amount is corrected based on the change amount of the residual fuel amount only in the low engine speed region.

[0006]

However, in the above-mentioned prior art, the valve opening pressure at the time of opening the fuel injection nozzle is used to obtain the amount of change in the residual fuel amount in the fuel system. Here, although the difference in valve opening pressure has some correlation with the difference in the amount of change in the residual fuel amount,
The amount of change in the residual fuel amount did not change directly due to the difference in valve opening pressure. Therefore, in order to ensure the required accuracy in correcting the fuel injection amount, the correction has to be performed only in the low engine speed region. Then, in a region other than the low rotation region, especially in the high rotation region, the amount of change in the residual fuel amount cannot be accurately obtained by the valve opening pressure, and there is a problem in the accuracy of the fuel injection amount correction. Further, especially in a direct injection type diesel engine, the fuel injection nozzle has a structure that increases the injection rate, so even if an attempt is made to obtain the amount of change in the remaining fuel amount from the difference in valve opening pressure, there is a large error. There was a risk of becoming.

The present invention has been made in view of the above-mentioned circumstances, and was made by paying attention to the fact that the residual fuel amount changes with a strong correlation with the valve closing pressure rather than the valve opening pressure of the fuel injection nozzle. Is. And the purpose is
A high-pressure injection internal combustion engine capable of accurately obtaining the difference in the residual fuel amount in the fuel system and performing more accurate fuel injection control regardless of the rotation range of the internal combustion engine, whether it is a direct injection type, or the like. It is to provide a fuel injection control device for an engine.

[0008]

In order to achieve the above object, according to the present invention, as shown in FIG. 1, a high pressure injection internal combustion engine M1 is opened by opening a valve to obtain a fuel pressure higher than a predetermined level. Fuel injection nozzle M2 for injecting fuel, fuel injection pump M3 that is drive-controlled to pump fuel to the fuel injection nozzle M2, and fuel pressure when the fuel injection nozzle M2 is closed is detected as valve closing pressure. Fuel pressure detecting means M4 for operating the fuel injection pump M3 based on the valve closing pressure detected by the fuel pressure detecting means M4.
To a fuel injection nozzle M2 to a residual fuel amount calculation means M6 for calculating a residual fuel amount in the fuel system M5,
A residual fuel amount deviation calculating means M7 for calculating a difference between the reference residual fuel amount when the fuel injection nozzle M2 is closed and the residual fuel amount calculated by the residual fuel amount calculating means M6 as a residual fuel amount deviation. , A control amount correction means M8 for correcting various control amounts for fuel injection based on the calculation result of the residual fuel amount deviation calculation means M7, and a fuel injection pump based on the correction result of the control amount correction means M8 M3
And a pump control means M9 for driving and controlling

[0009]

According to the above-described structure, as shown in FIG. 1, when the fuel is pumped from the fuel injection pump M3 to the fuel injection nozzle M2 and fuel injection is performed, the fuel pressure detection means M4 causes the fuel injection nozzle M2. The valve closing pressure is detected when the valve is closed. Further, in the residual fuel amount calculation means M6, the fuel system M5
The amount of residual fuel inside is calculated based on the valve closing pressure. Further, the residual fuel amount deviation calculation means M7 calculates the difference between the reference residual fuel amount when the valve is closed and the actually calculated residual fuel amount as the residual fuel amount deviation. Further, in the control amount correcting means M8, based on the calculated residual fuel amount deviation,
Various control amounts for fuel injection, such as the fuel injection amount and the fuel injection timing, are corrected. That is, the various control amounts are corrected according to the difference in the residual fuel amount that changes according to the difference in the valve closing pressure. Then, in the pump control means M9, the fuel injection pump M3 is drive-controlled based on the corrected various control amounts, and the fuel pressure-fed to the fuel injection nozzle M2 through the fuel system M5 is adjusted.

Here, the residual fuel amount corresponds to the amount of fuel actually confined in the fuel system M5 when the fuel injection nozzle M2 is closed. It is known that the residual fuel amount has a stronger correlation with the valve closing pressure than the valve opening pressure of the fuel injection nozzle M2, and changes directly due to the difference in the valve closing pressure. Further, it is known that the deviation of the residual fuel amount, that is, the difference in the residual fuel amount affects the difference in the fuel amount injected from the fuel injection nozzle M2, the injection timing thereof, and the like.

Therefore, a more appropriate residual fuel amount can be obtained from the valve closing pressure, and a more appropriate residual fuel amount deviation can be obtained. Further, at each fuel injection, the influence of the residual fuel amount is more appropriately excluded from the various control amounts for fuel injection, and the fuel injection control is performed without being affected by the change over time of the fuel injection nozzle M2. .

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the fuel injection control device for a high pressure injection internal combustion engine according to the present invention is embodied in an electronically controlled diesel engine for an automobile will be described in detail below with reference to FIGS.

FIG. 2 shows a schematic structure of a diesel engine system with a supercharger in this embodiment, and FIG. 3 shows the distribution type fuel injection pump 1 in an enlarged manner. The fuel injection pump 1 includes a drive pulley 2, and the drive pulley 2 is a diesel engine 3 as a high pressure injection internal combustion engine.
Is connected to the crankshaft 40 via a belt or the like. Then, the drive shaft 2 is rotated by the crankshaft 40 and the fuel injection pump 1 is driven, so that the fuel pipe is connected to the fuel injection nozzle 4 provided for each cylinder (four cylinders in this embodiment) of the diesel engine 3. Fuel is pumped through the path 4a.

In this embodiment, the fuel injection nozzle 4 is an automatic valve having a needle valve and a spring for adjusting the valve opening pressure of the needle valve, which is an automatic valve. The valve is opened. Therefore, the fuel pressure-fed from the fuel injection pump 1 applies the fuel pressure P of a predetermined level or higher to the fuel injection nozzle 4, so that the fuel is injected from the nozzle 4 to the diesel engine 3.

The fuel injection pump 1 has a drive shaft 5
Is provided, and the drive pulley 2 is attached to the tip of the drive shaft 5. A fuel feed pump (developed by 90 degrees in this figure) 6 made up of a vane type pump is provided in the middle of the drive shaft 5. A disc-shaped pulsar 7 is attached to the base end side of the drive shaft 5. On the outer peripheral surface of the pulsar 7, the same number as the number of cylinders of the diesel engine 3, that is, four teeth in this embodiment (a total of "eight") are formed at equal angular intervals. Also, between each missing tooth,
Fourteen protrusions (“56” in total) are formed at equal angular intervals. The base end of the drive shaft 5 is connected to the cam plate 8 via a coupling (not shown).

A roller ring 9 is provided between the pulsar 7 and the cam plate 8. A plurality of cam rollers 10 facing the cam face 8a of the cam plate 8 are mounted in the circumferential direction of the roller ring 9. The cam faces 8a are provided in the same number as the number of cylinders of the diesel engine 3. Also, the cam plate 8 is the spring 1
It is urged by 1 to engage the cam roller 10.

A base end of a plunger 12 for fuel pressurization is attached to the cam plate 8 so as to be integrally rotatable. Then, the cam plate 8 and the plunger 12 are integrally driven to rotate as the drive shaft 5 rotates.
That is, the rotational force of the drive shaft 5 is transmitted to the cam plate 8 via the coupling, so that the cam plate 8 is rotated while being engaged with the cam roller 10. As a result, while the cam plate 8 is rotated, the cam plate 8 is reciprocated in the left-right direction in the same number as the number of cylinders, and accordingly, the plunger 12 is rotated and reciprocated in the same direction. That is, the cam face 8 a is the cam roller 1 of the roller ring 9.
Plunger 12 moves forward (lift) in the process of climbing to 0
To be done. On the contrary, the cam face 8a has the cam roller 1
Plunger 12 returns (down) in the process of getting over 0
To be done.

A cylinder 14 is formed in the pump housing 13, and the plunger 12 is fitted in the cylinder 14. A high pressure chamber 15 is formed between the tip end surface of the plunger 12 and the bottom surface of the cylinder 14. Further, suction grooves 16 and distribution ports 17 are formed on the outer periphery of the tip end side of the plunger 12 in the same number as the number of cylinders. Furthermore, corresponding to the suction groove 16 and the distribution port 17,
A distribution passage 18 and an intake port 19 are formed in the pump housing 13.

In the pump housing 13 of this embodiment, the delivery valve 3 formed of a constant pressure valve (CPV) is provided on the outlet side of each distribution passage 18.
6 is provided. The delivery valve 36 is for preventing the reverse flow of the fuel pressure-fed from the distribution passage 18 to the fuel pipe 4a, and is opened when the fuel pressure P of a certain level or higher is obtained.

The drive shaft 5 is rotated and the fuel feed pump 6 is driven, so that fuel is introduced into the fuel chamber 21 from the fuel tank (not shown) through the fuel supply port 20. Further, in the suction stroke in which the plunger 12 is returned and the high pressure chamber 15 is depressurized, the suction groove 1
The fuel is introduced from the fuel chamber 21 into the high-pressure chamber 15 by communicating one of the six with the suction port 19. On the other hand, in the compression stroke in which the plunger 12 is moved forward and the high pressure chamber 15 is pressurized, fuel is pressure-fed and injected from the distribution passage 18 to the fuel injection nozzle 4 of each cylinder through the fuel pipe 4a.

In the pump housing 13, the high pressure chamber 1
A spill passage 22 for spilling fuel is formed between the fuel cell 5 and the fuel chamber 21. An electromagnetic spill valve 23 is provided in the spill passage 22. Then, the electromagnetic spill valve 23 is opened and closed in order to adjust the spill of fuel from the high pressure chamber 15. The electromagnetic spill valve 23 is a normally open type valve, and when the coil 24 is in a non-energized (off) state, the spill passage 22 is opened by the valve body 25, that is, the valve is opened, and the fuel in the high pressure chamber 15 is filled with fuel. Be spilled. On the other hand, when the coil 24 is energized (turned on), the spill passage 22 is closed or closed by the valve body 25, and the spill of fuel from the high pressure chamber 15 to the fuel chamber 21 is blocked.

Therefore, the electromagnetic spill valve 23 is controlled to be turned on and off by energization, so that the valve 23 is controlled to be closed and opened, and the spill of fuel from the high pressure chamber 15 to the fuel chamber 21 is adjusted. The electromagnetic spill valve 23 is opened during the compression stroke of the plunger 12, so that the high pressure chamber 1
The fuel in 5 is decompressed and the fuel injection from the fuel injection nozzle 4 is stopped. That is, even if the plunger 12 is moving forward, while the electromagnetic spill valve 23 is open,
The fuel pressure in the high pressure chamber 15 does not rise, and the fuel injection nozzle 4
Fuel is not injected from. Further, the opening timing of the electromagnetic spill valve 23 is controlled during the forward movement of the plunger 12, so that the end timing of the fuel injection from the fuel injection nozzle 4 is adjusted and the fuel injection amount to the cylinder is controlled. .

A timer device (developed by "90 degrees" in this figure) 26 for controlling the fuel injection timing to the advance side or the retard side is provided below the pump housing 13. . The timer device 26 changes the time when the cam face 8a engages the cam roller 10, that is, the time when the plunger 12 reciprocates by changing the rotational position of the roller ring 9 with respect to the rotational direction of the drive shaft 5. belongs to.

The timer device 26 is driven by control hydraulic pressure, and includes a timer housing 27 and a timer piston 28 fitted in the housing 27. Further, in the timer housing 27, a low pressure chamber 29 and a pressurizing chamber 30 are formed on both sides of the timer piston 28, respectively. Then, in the low pressure chamber 29, the timer piston 28
A timer spring 31 is provided for urging the pressure chamber 30 into the pressurizing chamber 30. Further, the timer piston 28 is connected to the roller ring 9 via a slide pin 32.

Fuel pressurized by the fuel feed pump 6 is introduced into the pressurizing chamber 30. The position of the timer piston 28 is determined by the equilibrium relationship between the fuel pressure and the urging force of the timer spring 31. Further, the position of the roller ring 9 is determined by determining the position of the timer piston 28, and the reciprocating timing of the plunger 12 is determined via the cam plate 8.

The fuel pressure inside the fuel injection pump 1 is used as the control oil pressure of the timer device 26. The timer device 26 is provided with a timer control valve (TCV) 33 for adjusting the fuel pressure. That is, the communication passage 34 is provided between the pressurizing chamber 30 and the low pressure chamber 29 of the timer housing 27.
TCV33 is provided on the way. The TCV 33 is a solenoid valve whose opening is controlled by a duty-controlled energizing signal, and the fuel pressure in the pressurizing chamber 30 is adjusted by controlling the opening of the TCV 33. Then, by adjusting the fuel pressure, the reciprocating timing of the plunger 12 is controlled, so that the fuel injection nozzle 4
The fuel injection timing from is controlled to the advance side or the retard side.

On the upper part of the roller ring 9, a rotation speed sensor 35 composed of an electromagnetic pickup coil is attached so as to face the outer peripheral surface of the pulsar 7. This rotation speed sensor 35
Detects the passage of the pulsar 7 when it is traversed by the protrusion of the pulsar 7 and outputs it as a pulse signal. That is, the rotation speed sensor 35 outputs an engine rotation pulse signal for each constant crank angle. At the same time, the rotation speed sensor 35 outputs, as a reference position signal, an engine rotation pulse signal corresponding to a constant crank angle due to the missing tooth of the pulsar 7. Further, the rotation speed sensor 35 outputs a series of engine rotation pulse signals as a signal for obtaining the engine rotation speed NE.
Since the rotation speed sensor 35 is integrated with the roller ring 9, it is possible to output a reference engine rotation pulse signal with respect to the reciprocating movement of the plunger 12 at a constant timing regardless of the control operation of the timer device 26. .

In addition, the pump housing 13 is provided with a fuel temperature sensor 37 for detecting the temperature of the fuel contained in the fuel chamber 21, that is, the fuel temperature THF.

Next, the diesel engine 3 will be described. In FIG. 2, in the diesel engine 3, a main combustion chamber 44 corresponding to each cylinder is formed by the cylinder bore 41, the piston 42, and the cylinder head 43. Further, the cylinder head 43 is formed with auxiliary combustion chambers 45 communicating with the respective main combustion chambers 44. Then, the fuel is injected from each fuel injection nozzle 4 into each auxiliary combustion chamber 45. Each sub-combustion chamber 45 is provided with a well-known glow plug 46 as a starting assist device.

As shown in FIGS. 2 and 4, each fuel injection nozzle 4 of this embodiment is provided with a pressure sensor 47 as a fuel pressure detecting means. The pressure sensor 47 detects the pressure of the fuel sent from the fuel injection pump 1 to each fuel injection nozzle 4, that is, the fuel pressure P, and
The fuel pressure P when the valve is closed is detected as the valve closing pressure, and a signal corresponding to the magnitude of the detected value is output.

On the other hand, the diesel engine 3 is provided with an intake passage 49 and an exhaust passage 50 which communicate with each cylinder. Further, the intake passage 49 is provided with a compressor 52 of a turbocharger 51 that constitutes a supercharger,
The exhaust passage 50 has a turbine 53 of a turbocharger 51.
Is provided. Further, a waste gate valve 54 is provided in the exhaust passage 50. As is well known, the turbocharger 51 uses the energy of the exhaust gas to rotate the turbine 53 and the compressor 52 coaxially with the turbine 53 to rotate the pressure of the intake air. Then, by boosting the pressure of the intake air, high-density air is sent to the main combustion chamber 44, a large amount of fuel injected through the auxiliary combustion chamber 45 is burned, and the output of the diesel engine 3 is increased. Further, by opening and closing the waste gate valve 54, the turbocharger 5
The boosting level of the intake air by 1 is adjusted.

Between the intake passage 49 and the exhaust passage 50,
Exhaust gas recirculation valve passage (EG
R passage) 56 is provided. Then, a part of the exhaust gas in the exhaust passage 50 is recirculated to the vicinity of the intake port 55 in the intake passage 49 by the EGR passage 56.
An EGR valve 57 is provided in the middle of the EGR passage 56, and the EGR valve 57 allows the exhaust gas recirculation amount (E
GR amount) is adjusted. Further, an electric vacuum regulating valve (EVRV) 58 whose opening is adjusted to open and close the EGR valve 57.
Is provided. Then, the EGRV 58 causes EGR
The EGR passage 5 is opened and closed by driving the valve 57.
E guided from the exhaust passage 50 to the intake passage 49 through 6
The amount of GR is adjusted.

A throttle valve 59 is provided in the middle of the intake passage 49, and the valve 59 is opened and closed in conjunction with the depression of the accelerator pedal 60. Also, in the intake passage 49,
A bypass passage 61 is provided alongside the throttle valve 55, and a bypass throttle valve 62 is provided in the passage 61. A two-stage diaphragm chamber actuator 63 is provided to open and close the bypass throttle valve 62. Also, two vacuum switching valves (VS for driving the actuator 63)
V) 64, 65 are provided. And each VSV6
The bypass throttle valve 62 is controlled to be opened / closed by controlling the on / off of the valves 4 and 65 and driving the actuator 63. For example, the bypass throttle valve 62 is controlled to a half open state to reduce noise and vibration during idle operation, to a fully open state to normal operation, and to a fully closed state to smoothly stop when the operation is stopped. To be done.

The electromagnetic spill valve 23, TCV3 as described above
3, glow plug 46, EVRV58 and each VSV6
4, 65 are electronic control units (hereinafter simply referred to as "ECU")
71 are electrically connected to each other. Then, the drive timing of each of the members 23, 33, 46, 58, 64, 65 is controlled by the ECU 71.

As a sensor for detecting the operating state of the diesel engine 3, the following various sensors are provided in addition to the rotation speed sensor 35 described above. That is, in the vicinity of the air cleaner 66 provided at the inlet of the intake passage 49, the temperature of the air taken into the intake passage 49, that is, the intake air temperature THA is detected and a signal corresponding to the magnitude of the detected value is output. An intake air temperature sensor 72 is provided. An accelerator sensor 73 is provided near the throttle valve 59 to detect the accelerator opening ACCP corresponding to the engine load from the open / close position of the valve 59 and output a signal corresponding to the detected value. There is. In the vicinity of the intake port 55, an intake pressure sensor 74 that detects the pressure of the intake air after being supercharged by the turbocharger 51, that is, the supercharging pressure PiM, and outputs a signal according to the magnitude of the detected value. It is provided. Further, the diesel engine 3 is provided with a water temperature sensor 75 that detects the temperature of the cooling water, that is, the cooling water temperature THW, and outputs a signal according to the magnitude of the detected value. Further, the diesel engine 3 is provided with a crank angle sensor 76 which detects a rotation reference position of the crankshaft 40, for example, a rotation position of the crankshaft 40 with respect to a top dead center of a specific cylinder, and outputs a signal corresponding to the rotation position. Has been. Furthermore, the transmission (not shown) is provided with a vehicle speed sensor 77 for detecting the vehicle speed (vehicle speed) SPD. This vehicle speed sensor 7
7 includes a magnet 77a rotated by the output shaft of the transmission, and the magnet 77a periodically turns on the reed switch 77b, thereby outputting a pulse signal corresponding to the vehicle speed SPD.

In this embodiment, the ECU 71 constitutes a residual fuel amount calculation means, a residual fuel amount deviation calculation means, a control amount correction means and a pump control means. The above-described sensors 72 to 77, the rotation speed sensor 35, the fuel temperature sensor 37, and the pressure sensor 47 are connected to the ECU 71. In addition, the ECU 71 uses each sensor 3
5, 37, 47, 72 to 77, the electromagnetic spill valve 23, the TCV 33, the glow plug 4
6, EVRV58 and each VSV64,65 etc. are controlled suitably.

Next, the structure of the above-mentioned ECU 71 will be described with reference to the block diagram of FIG. The ECU 71 includes a central processing unit (CPU) 81, a read-only memory (ROM) 82 in which a predetermined control program, maps and the like are stored in advance, and
A random access memory (RAM) 83 for temporarily storing the calculation result of the PU 81, a backup RAM 84 for storing the stored data, and the like are provided. And the ECU
Reference numeral 71 is configured as a logical operation circuit in which these units 81 to 84 are connected to the input port 85, the output port 86 and the like by a bus 87.

At the input port 85, the intake air temperature sensor 72, the accelerator sensor 73, the intake air pressure sensor 74, the water temperature sensor 75, the pressure sensor 47, and the fuel temperature sensor 37 are connected to the buffers 88, 89, 90, 91, 92. , 93, a multiplexer 94, and an A / D converter 95. Similarly, the input port 85 is connected to the rotation speed sensor 35, the crank angle sensor 76, and the vehicle speed sensor 77 described above.
Are connected via the waveform shaping circuit 96. Then, the CPU 81 reads the signals from the sensors 35, 37, 47, 72 to 77, etc., which are input via the input port 85, as input values. Further, the output port 86 is connected to the respective drive circuits 97, 98, 99, 100, 101, 102.
The electromagnetic spill valve 23, the TCV 33, the glow plug 46, the EVRV 58, the VSVs 64, 65, etc. are connected to each other via the. Then, the CPU 81 uses the sensors 3
The electromagnetic spill valve 23, the TCV 33, the glow plug 46, the EVRV 58, the VSVs 64, 65, and the like are preferably controlled based on the input values read from the 5, 37, 47, 72 to 77.

In this embodiment, the CPU 81 also has a timer function. Also, in this embodiment,
The glow plug 46 and the pressure sensor 47 are provided for each cylinder of the diesel engine 3 as shown in FIG.
Only one of them is shown in the block diagram of FIG.

Next, the processing operation for the fuel injection control executed by the above-mentioned ECU 71 will be described with reference to FIGS.
Follow the instructions below. FIG. 6 is a flowchart showing a “subroutine” process executed at each time ti measured by the timer function of the CPU 81 among the processes executed by the ECU 71.

When the processing shifts to this routine, first, at step 110, the fuel pressure P is sampled based on the signal from the pressure sensor 47. Then, in step 120, the fuel pressure Pi at that time ti is calculated.

Next, at step 130, the one-time differential value (dPi / dti) is calculated as the rate of change of the fuel pressure Pi at the time ti at that time. Further, in step 140, the fuel pressure P at the time ti at that time
The second derivative (d ² Pi / d) corresponding to the change in the rate of change of i
ti ² ) is calculated.

Then, in step 150, the fuel pressure Pi obtained this time and the once differentiated value (dPi / dt
i) and the second derivative (d ² Pi / dti ² ) at time ti
Is stored in the RAM 83 as calculation data corresponding to, and the subsequent processing is temporarily terminated.

Therefore, according to the above-mentioned "subroutine" processing, the fuel pressure Pi corresponding to each time ti and the one-time differential value (dPi / dti) each time one fuel injection is executed.
And the twice differentiated value (d ² Pi / dti ² ) are sequentially stored in the RAM 83 as calculation data.

FIG. 7 and FIG. 8 are "Pe calculation routines" for calculating the injection end pressure Pe and the like used for fuel injection control among the processes executed by the ECU 71.
5 is a flowchart showing the processing contents of FIG. The processing of this routine is executed every time fuel is injected once.

When the processing shifts to this routine, first, at step 210, the fuel pressure Pi corresponding to the time ti stored in the RAM 83 and its one-time differential value (d).
Pi / dti) and the time t (i-
The fuel pressure P (i-1) corresponding to 1) is read.

Then, at step 220, time t
The fuel pressure Pi corresponding to i is the time t (i-
It is determined whether or not the fuel pressure is larger than the fuel pressure P (i-1) corresponding to 1). When the fuel pressure Pi is not higher than the previous fuel pressure P (i-1), the fuel pressure P
Assuming that the process is not increasing, the process jumps to step 210 and the processes of steps 210 and 220 are repeated.
If the fuel pressure Pi is higher than the previous fuel pressure P (i-1) in step 220, the process proceeds to step 230 as the process of increasing the fuel pressure P.

In step 230, it is determined whether or not the one-time differential value (dPi / dti) read this time exceeds a predetermined threshold value d1 on the plus side and a predetermined reference time T1 has elapsed. Here, the one-time differential value (dPi / dt
When i) exceeds the threshold value d1 and the reference time T1 has not elapsed, the process jumps to step 210 and the processes of steps 210 to 230 are repeated. Also, step 23
At 0, if the once-differential value (dPi / dti) exceeds the threshold value d1 and the reference time T1 has elapsed, it is determined that it is the process of increasing the fuel pressure P that should lead to the start of fuel injection, and step 240 Move to.

Then, in step 240, RA
Fuel pressure P corresponding to time ti stored in M83
i first derivative (dPi / dti) and second derivative (d
² Pi / dti ² ) respectively.

Next, at step 250, it is judged whether or not the twice-differentiated value (d ² Pi / dti ² ) read this time is smaller than a reference value α. Here, if the twice differentiated value (d ² Pi / dti ² ) is not smaller than the reference value α, it is determined that the rate of change of the fuel pressure Pi has not dropped significantly, and the routine jumps to step 240, The processing of 250 is repeated. On the other hand, in step 250, the second derivative (d ² Pi / dt
If i ² ) is smaller than the reference value α, it is determined that the rate of change of the fuel pressure P has dropped significantly during the process of increasing the fuel pressure P, and the process proceeds to step 260.

Then, at step 260, the once-read differential value (dPi / dti) read this time falls below a predetermined threshold value d2 on the minus side and a predetermined reference time T2.
Just determine whether or not it has passed. Here, when the one-time differential value (dPi / dti) is less than the threshold value d2 and the reference time T2 has not elapsed, the one-time differential value (dPi / dti) is changed due to the start of the fuel injection. Assuming that no change has occurred, the process jumps to step 240 and the processes of steps 240 to 260 are repeated. Also, step 26
At 0, when the one-time differential value (dPi / dti) falls below the threshold value d2 and the reference time T2 has elapsed, the one-time differential value (dPi / dti) is caused by the start of fuel injection.
., That is, the decrease in the rate of change of the fuel pressure P has certainly occurred, the process proceeds to step 270.

In step 270, the RAM 83 is traced back to the time ti at which the one-time differential value (dPi / dti) becomes "0" from the time when it is judged that the decrease in the rate of change of the fuel pressure P has definitely occurred. Search the stored calculation data. Here, the time ti at which the once-differential value (dPi / dti) becomes “0” is the time when the rate of increase of the fuel pressure P first changes from positive to negative during the process of increasing the fuel pressure P. It corresponds.

Then, in step 280, at the time ti at which the once-differential value (dPi / dti) becomes "0" in the retrieved calculation data, the time ti is set to the fuel injection from the fuel injection nozzle 4. The start time is determined and the time ti is set as the injection start time ts. Further, the fuel pressure Pi at the time ts is set as the injection start pressure Ps corresponding to the valve opening pressure when the fuel injection nozzle 4 is opened.

Subsequently, in step 290, the RAM
Fuel pressure Pi corresponding to time ti stored in 83
And the fuel pressure P (i-1) corresponding to the time t (i-1) immediately before the time ti.

Next, at step 300, it is judged if the fuel pressure Pi read this time is smaller than the injection start pressure Ps obtained at step 280. Then, when the fuel pressure Pi is not lower than the injection start pressure Ps, the routine jumps to step 290 and step 29
Each processing of 0,300 is repeated. If the fuel pressure Pi is smaller than the injection start pressure Ps in step 300, the process proceeds to step 310.

In step 310, it is determined whether the fuel pressure Pi corresponding to the time ti is smaller than the fuel pressure P (i-1) corresponding to the immediately preceding time t (i-1). The fuel pressure Pi is the previous fuel pressure P.
If it is not smaller than (i-1), it is determined that the fuel pressure P is not in the process of decreasing, and the process jumps to step 290 and the processes of steps 290 to 310 are repeated. or,
In step 310, when the fuel pressure Pi is lower than the previous fuel pressure P (i-1), the fuel pressure P is in the range lower than the injection start pressure Ps, and the fuel injection ends. As the range that should reach
Go to step 320.

In step 320, the elapsed time Toff from the time when the electromagnetic spill valve 23 is turned off, that is, the valve is closed prior to the current fuel injection stroke, is read. The elapsed time Toff is counted up by a separate processing routine. And step 33
0, whether the elapsed time Toff read this time is smaller than a predetermined reference time T3, that is, the elapsed time Toff.
It is determined whether off has not reached the reference time T3. Here, when the elapsed time Toff has reached the reference time T3, the subsequent processing is temporarily terminated.
On the other hand, when the elapsed time Toff has not reached the reference time T3, the fuel injection end timing is determined.
Control goes to step 340.

In step 340, the one-time differential value (dPi / dti) of the fuel pressure Pi corresponding to the time ti stored in the RAM 83 is read. Then, in step 350, the once-read differential value (dP
i / dti) is smaller than a certain threshold value d3 on the negative side. Here, the one-time differential value (dPi /
If dti) is not smaller than the threshold value d3, it is determined that the rate of change of the fuel pressure P is not sufficiently small, that is, the rate of decrease of the fuel pressure P is not in the increasing process, and the routine jumps to step 340. The processing of steps 340 and 350 is repeated. On the other hand, in step 350,
When the one-time differential value (dPi / dti) is smaller than the threshold value d3, it is determined that the decreasing rate of the fuel pressure P is in the process of increasing, and the process proceeds to step 360.

In step 360, the one-time differential value (dPi / dti) of the fuel pressure Pi corresponding to the time ti stored in the RAM 83 is read. Then, in step 370, the once read differential value (dP
i / dti) is a negative threshold value d4 (d3 <
It is determined whether it is larger than d4). Here, if the one-time differential value (dPi / dti) is not larger than the threshold value d4, it is assumed that the rate of change of the fuel pressure P has not increased from a small state, that is, the rate of decrease of the fuel pressure P. Is not changed from the increasing process to the decreasing process, the process jumps to step 360, and step 36
The processing of 0 and 370 is repeated. On the other hand, step 3
At 70, if the once-differential value (dPi / dti) is larger than the threshold value d4, it is determined that the decreasing rate of the fuel pressure P has changed from the increasing process to the decreasing process, and the process proceeds to step 380.

In step 380, the time ti at the time when the once-differential value (dPi / dti) becomes larger than the threshold value d4 in the immediately preceding step 370 is defined as the fuel injection end timing in the fuel injection nozzle 4. It is determined and the time ti is set as the injection end time te. In addition, “te-T”, which is before the injection end time te by the correction time TP,
The fuel pressure Pi at the time of “P” is set to the fuel injection nozzle 4
Injection end pressure Pe corresponding to the valve closing pressure when the valve is closed
Set as. Here, it is known that the fuel pressure P at the actual injection end time te is slightly delayed on the waveform detected by the pressure sensor 47 due to the fuel properties of the fuel system, the path length, and the like. The correction time TP is to compensate for the delay, and is an extremely short time set according to the difference in the conditions of the fuel system. Here, the correction time TP can be set to “20 to 100 μs”.

When the processing of step 380 is completed, the subsequent processing is once terminated, the next fuel injection is awaited, and the processing from step 210 is started again. Therefore, according to the process of the "Pe calculation routine" described above, every time fuel injection is performed, the injection start time ts and the injection start pressure Ps at that time, and the injection end time te and the injection end thereof are executed. The pressure Pe is calculated respectively. Then, those values are stored in the RAM 83, respectively.

Here, the injection start time ts, the injection start pressure Ps, the injection end time te, the injection end pressure Pe, the fuel pressure P and the one-time differential value (dPi) obtained as described above.
An example of the behavior of / dti) will be described with reference to the time chart of FIG.

When the plunger 12 of the fuel injection pump 1 starts to move forward when fuel is injected from the fuel injection nozzle 4, the fuel pressure P increases at time t1 as shown in FIG. Begin to. And the fuel pressure P
Gradually increases as the plunger 12 moves forward. At this time, the one-time differential value (dP / dt) of the fuel pressure P shows a change as shown in FIG. Here, when the differential value (dP / dt) once exceeds the threshold value d1 on the plus side and elapses for the reference time T1 immediately after time t1, the ECU 71 determines that
It is determined that the fuel pressure P is increasing until the fuel injection starts. After that, at time t2, when the increasing fuel pressure P largely changes, its first derivative (dP /
dt) drops significantly. Then, immediately after time t2,
One-time differential value (dP / dt) is a negative threshold value d2
When the reference time T2 has passed, the ECU 71 determines that the decrease in the rate of change of the fuel pressure P has certainly occurred due to the start of fuel injection. Further, in the ECU 71,
One-time differential value (dPi / dti) traced back from the time of judgment
Is obtained as “0”, and the time t2 is obtained as the injection start time ts. Further, the time t2
Is obtained as the injection start pressure Ps corresponding to the valve opening pressure. That is, as shown in FIG. 7A, the injection start time ts corresponding to the inflection point A at which the rate of increase of the fuel pressure P first changes from positive to negative and the injection start pressure Ps at that time are obtained. .

After that, when fuel injection continues from time t2,
Along with that, the fuel pressure P and the one-time differential value (dPi / dt
i) shows the changes as shown in FIGS. Then, in the process in which the fuel pressure P decreases in a range lower than the injection start pressure Ps, if the one-time differential value (dPi / dti) of the fuel pressure P falls below the negative threshold d3 at the time t3 and falls significantly. , In the ECU 71, the fuel pressure P
It is judged that this is an increasing process of the decrease rate of. Continuing time t4
At, the first derivative of fuel pressure P (dPi / dti)
Once exceeds the negative threshold d4 and rises significantly, the ECU 71 determines that it is the time when the decreasing rate of the fuel pressure P changes from the increasing process to the decreasing process. Then, the time t4 is obtained as the injection end time te in the fuel injection nozzle 4. Also, the time t
4 before the correction time TP (in this case, the time t
The fuel pressure P in 3) is obtained as the injection end pressure Pe corresponding to the valve closing pressure. That is, as shown in FIG. 6A, the injection end time te and the injection end pressure Pe at that time corresponding to the inflection point B at which the decrease temporarily stops in the process of decreasing the fuel pressure P are obtained. Be done. Then, from the injection start time ts to the injection end time te
Up to is the injection period during which the fuel injection is actually performed.

Then, in this embodiment, the following fuel injection amount control is executed by using the injection end pressure Pe obtained as described above. That is, FIG.
5 is a flowchart showing the processing contents of a "fuel injection amount control routine" executed by the above, which is periodically executed at predetermined intervals.

When the processing shifts to this routine, first, at step 410, the engine speed NE is based on various signals from the rotation speed sensor 35, the fuel temperature sensor 37, the accelerator sensor 73, the intake pressure sensor 74, the water temperature sensor 75 and the like. , Fuel temperature THF, accelerator opening ACCP, supercharging pressure PiM, cooling water temperature THW, etc. are read.

Next, at step 420, the basic injection amount Qb according to the present operating state is calculated based on the engine speed NE and the accelerator opening degree ACCP. or,
In step 430, the basic injection amount Qb calculated this time is calculated based on the current cooling water temperature THW, the boost pressure PiM, and the like.
The corrected injection amount Q1 is obtained by performing a correction calculation of That is, the post-correction injection amount Q1 is obtained according to the cold state or the operating state of the turbocharger 51.

Further, in step 440, the fuel temperature THF read this time and the corrected injection amount Q found this time are obtained.
1 based on 1, the reference residual fuel amount that will remain in the fuel system from the fuel injection pump 1 to the fuel injection nozzle 4 when the fuel injection nozzle 4 is closed, that is, the reference residual fuel amount Qr.
Calculate es. This calculation is performed with reference to a predetermined map regarding the relationship between the fuel temperature THF and the reference residual fuel amount Qres with respect to the corrected injection amount Q1.

Then, in step 450, the RAM
The latest injection end pressure Pe stored in 83 is read. Then, in step 460, the actual residual fuel amount Qre remaining in the fuel system from the fuel injection pump 1 to the fuel injection nozzle 4 is calculated based on the latest injection end pressure Pe read this time. This residual fuel quantity Qre
The calculation of is performed according to the following calculation formula.

Qre = Vi * ε * Pe Here, “Vi” means the volume volume in the fuel system from the fuel injection pump 1 to the fuel injection nozzle 4, and “ε”.
Means the bulk modulus of the fuel. Therefore, in the above calculation formula, the actual residual fuel amount Qre is calculated based on the actual injection end pressure Pe.

Then, in step 470, the difference between the currently calculated reference residual fuel amount Qres and the actual residual fuel amount Qre is calculated, and the calculation result is set as the residual fuel amount deviation ΔQre.

Then, in step 480, the corrected injection amount Q1 and the residual fuel amount deviation ΔQre obtained this time are calculated.
Based on, the final target injection amount Q is calculated. That is, the target injection amount Q is obtained by further correcting the post-correction injection amount Q1 by the residual fuel amount deviation ΔQre.

Then, in step 490, fuel injection is executed based on the target injection amount Q found this time, and the subsequent processing is temporarily terminated. That is, by controlling the electromagnetic spill valve 23 on the basis of the target injection amount Q, the pressure feed of fuel from the fuel injection pump 1 to the fuel injection nozzle 4 is controlled, and thus the fuel injection amount injected from the fuel injection nozzle 4 is controlled. To do.

As described above, according to the fuel injection control device of this embodiment, the deviation of the residual fuel amount Qre in the fuel system from the fuel injection pump 1 to the fuel injection nozzle 4 is the target injection amount. The fuel injection amount control is executed by being fed back to Q.

That is, when the fuel injection is performed once, the injection end pressure Pe corresponding to the valve closing pressure when the fuel injection nozzle 4 is closed is detected. Further, based on the detected injection end pressure Pe, the actual residual fuel amount Qr in the fuel system from the fuel injection pump 1 to the fuel injection nozzle 4
e is calculated. Further, the difference between the reference residual fuel amount Qres when the fuel injection nozzle 4 is closed and the actual residual fuel amount Qre is calculated as the residual fuel amount deviation ΔQre. Then, the corrected target injection amount Q is obtained by correcting the post-correction injection amount Q1 obtained according to the operating state based on the residual fuel amount deviation ΔQre. That is,
Injection end pressure P corresponding to the valve closing pressure of the fuel injection nozzle 4
The target injection amount Q is obtained by correcting the post-correction injection amount Q1 with the residual fuel amount deviation ΔQre corresponding to the difference in e. Then, the fuel injection pump 1 is drive-controlled based on the target injection amount Q, so that the amount of fuel pressure-fed to the fuel injection nozzle 4 through the fuel system is controlled.

Here, the residual fuel amount Qre corresponds to the amount of fuel actually confined in the fuel system when the fuel injection nozzle 4 is closed. Then, the residual fuel amount Qre
Has a stronger correlation with the valve closing pressure than the valve opening pressure of the fuel injection nozzle 4, and the injection end pressure Pe corresponding to the valve closing pressure Pe
It has been confirmed that the difference is directly caused by the difference.
Further, the residual fuel amount deviation ΔQre, that is, the residual fuel amount Qr
It has been confirmed that the difference in e affects the difference in the amount of fuel injected from the fuel injection nozzle 4.

Therefore, a more appropriate residual fuel amount Qre is obtained from the injection end pressure Pe, and by extension, a more appropriate residual fuel amount deviation ΔQre is obtained. Further, in each fuel injection, the residual fuel amount Qre is changed from the target injection amount Q of the target.
Is more appropriately eliminated, and the fuel injection amount control is executed without being affected by the change over time of the fuel injection nozzle 4.

As a result, in controlling the fuel injection quantity, the residual fuel quantity deviation Δ
It is possible to accurately correct the fuel injection amount based on Qre. Further, also in a direct injection type diesel engine in which the injection rate of the fuel injection nozzle is increased, a more appropriate residual fuel amount deviation ΔQre can be obtained from the injection end pressure Pe, and more accurate fuel injection amount control can be performed. Can be executed. That is, the difference in the residual fuel amount Qre in the fuel system can be accurately obtained regardless of the rotation range of the diesel engine 3 or whether it is the direct injection type, and thus the control of the conventional technique is performed. It is possible to execute the fuel injection amount control with higher accuracy than in the above. Further, as a result, smoke and emission of nitrogen oxides (NOx) from the diesel engine 3 can be suppressed more appropriately.

Moreover, in this embodiment, more concrete examination is made in obtaining the injection end pressure Pe in the fuel injection nozzle 4. That is, the waveform of the fuel pressure P is monitored by the pressure sensor 47 provided in the fuel injection nozzle 4. Then, when the fuel pressure P is in the decreasing process in the range lower than the injection start pressure Ps, the decreasing rate of the fuel pressure P changes from the once differential value (dPi / dti) to the decreasing process once. The time is required.
Here, the place where the decreasing rate of the fuel pressure P changes from the increasing process to the decreasing process corresponds to a portion where the decrease of the fuel pressure P stops once when the fuel injection nozzle 4 is closed. That is, in the waveform patterns shown in FIGS. 9A and 9B, in the decreasing process of the fuel pressure P, the time when the decreasing rate changes from the increasing process to the decreasing process is the fuel pressure P.
Means the inflection point B when the value stops for a moment.

Therefore, the actual injection end time te is specified from the inflection point B of the fuel pressure P, and the injection end pressure Pe corresponding to the valve closing pressure is specified from the injection end time te. It Therefore, a more appropriate injection end pressure Pe can be obtained by eliminating influences of the fuel injection nozzle 4 over time, individual differences, noise, and the like. As a result, the injection end pressure Pe can be obtained more accurately, and the residual fuel amount Qre and the residual fuel amount deviation ΔQre, and by extension, the target injection amount Q can be obtained more accurately. In that sense, the fuel injection amount control can be performed with higher accuracy.

Further, in this embodiment, in order to control the fuel injection amount from the fuel injection nozzle 4 to the target injection amount Q, the fuel amount itself pumped from the fuel injection pump 1 is adjusted. . Therefore, unlike the configuration in which a special pressure adjusting means is provided to adjust the valve opening pressure or the valve closing pressure of the fuel injection nozzle, the present embodiment does not complicate the mechanism for fuel injection. It is sufficient to use the fuel injection nozzle 4 that is the same as before.

The present invention is not limited to the above-described embodiment, but may be implemented as follows with a part of the configuration appropriately changed without departing from the spirit of the invention. (1) In the above embodiment, the target injection amount Q is obtained by correcting the post-correction injection amount Q1 based on the residual fuel amount deviation ΔQre, and the fuel injection amount control is executed based on the target injection amount Q. did. In contrast, the residual fuel amount deviation Δ
The target injection start timing may be determined by correcting the injection start timing based on Qre, and the fuel injection timing control may be executed based on the target injection start timing.
That is, as the various control amounts for fuel injection to be corrected, the fuel injection timing and the like can be mentioned in addition to the fuel injection amount.

(2) In the above embodiment, the injection end time te
From the correction time TP to the fuel pressure Pi
Was set as the injection end pressure Pe corresponding to the valve closing pressure. On the other hand, for example, the average value of the fuel pressure Pi obtained in the range of “20 to 100 μs” traced from the injection end time te is set as the injection end pressure Pe, or “20 to 100 μs traced from the injection end time te. The fuel pressure Pi at a specific time point during the period "" may be set as the injection end pressure Pe.

(3) In the above embodiment, in order to obtain the injection end pressure Pe corresponding to the valve closing pressure, the injection start time ts
Although the injection start pressure Ps at that time is actually obtained and used, the injection end pressure may be obtained by using a predetermined injection start time or injection start pressure.

(4) In the above embodiment, the pressure sensor 47 for detecting the fuel pressure P is used as the fuel injection nozzle 4 of each cylinder.
However, the pressure sensor may be provided in the middle of the fuel pipe communicating with each fuel injection nozzle, or may be provided corresponding to the high pressure chamber of the fuel injection pump.

(5) In the above embodiment, the diesel engine 3 as a high pressure injection internal combustion engine is embodied, but any high pressure injection internal combustion engine equipped with a fuel injection pump and a fuel injection nozzle is limited to a diesel engine. Instead, it can be embodied in a high-pressure gasoline injection engine or the like.

[0087]

As described above in detail, according to the present invention, the residual fuel amount in the fuel system is calculated based on the valve closing pressure of the fuel injection nozzle. Further, the difference between the reference residual fuel amount at the time of valve closing and the calculated residual fuel amount is calculated as the residual fuel amount deviation, and various control variables for fuel injection are calculated based on the calculated residual fuel amount deviation. Is being corrected. Then, the fuel injection pump is drive-controlled based on the corrected various control amounts. Therefore, a more appropriate residual fuel amount can be obtained from the valve closing pressure, and thus a more appropriate residual fuel amount deviation can be obtained. Further, in each fuel injection, the influence of the residual fuel amount is more appropriately excluded from the various control amounts for fuel injection, and the fuel injection control is performed without being affected by the change over time of the fuel injection nozzle.
As a result, it is possible to accurately determine the difference in the residual fuel amount in the fuel system regardless of whether the internal combustion engine is in the rotation range or whether it is a direct injection type, and execute highly accurate fuel injection control. It has the excellent effect of being able to.

[Brief description of drawings]

FIG. 1 is a conceptual configuration diagram illustrating a basic conceptual configuration of the present invention.

FIG. 2 is a schematic configuration diagram showing a diesel engine system with a supercharger in an embodiment embodying the present invention.

FIG. 3 is a cross-sectional view showing a distributed fuel injection pump in one embodiment.

FIG. 4 is a diagram showing a pressure sensor provided in a fuel injection nozzle in one embodiment.

FIG. 5 is a block diagram showing a configuration of an ECU in one embodiment.

FIG. 6 is a flowchart showing the processing of a “subroutine” executed by the ECU in one embodiment.

FIG. 7 illustrates a “P” executed by an ECU in one embodiment.
7 is a flowchart showing a process of an "e calculation routine".

FIG. 8 is the same “Pe calculation routine” in one embodiment.
It is a flowchart which shows the process of.

FIG. 9 is a time chart for explaining the behavior of the fuel pressure and its differential value once obtained during one fuel injection in one embodiment.

FIG. 10 is a flowchart showing a process of a “fuel injection amount control routine” executed by an ECU in one embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Fuel injection pump, 3 ... Diesel engine as a high pressure injection internal combustion engine, 4 ... Fuel injection nozzle, 47 ... Pressure sensor as fuel pressure detection means, 71 ... Residual fuel amount calculation means, Residual fuel amount deviation calculation means, control An ECU that constitutes a quantity correction means and a pump control means.

Claims (1)

[Claims] 1. A fuel injection nozzle for injecting fuel to a high-pressure injection internal combustion engine, which is opened when a fuel pressure of a predetermined level or higher is obtained, and fuel which is drive-controlled for pressure-feeding the fuel to the fuel injection nozzle. An injection pump, fuel pressure detection means for detecting the fuel pressure when the fuel injection nozzle is closed as a valve closing pressure, and based on the valve closing pressure detected by the fuel pressure detection means, from the fuel injection pump A residual fuel amount calculation means for calculating the residual fuel amount in the fuel system up to the fuel injection nozzle, a reference residual fuel amount when the fuel injection nozzle is closed, and the residual fuel amount calculation means. The residual fuel amount deviation calculating means for calculating a difference from the residual fuel amount deviation as a residual fuel amount deviation, and fuel injection based on the calculation result of the residual fuel amount deviation calculating means. Control amount correction means for correcting various control amounts for controlling the fuel injection pump based on the correction result of the control amount correction means. Fuel injection control device for internal combustion engine.