JP3067583B2 - Diesel engine control unit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control system for a diesel engine for controlling a fuel injection amount and an exhaust gas recirculation system in a diesel engine, and more particularly to a diesel engine suitable for suppressing output torque fluctuation and diesel smoke. The present invention relates to an engine control device.

[0002]

2. Description of the Related Art Conventionally, in a control device of a diesel engine, in order to suppress a sudden output torque fluctuation at the time of acceleration, based on a final injection amount command value to be finally supplied to a combustion chamber by a fuel injection pump. Annealing treatment has been applied. As a result, the change in the final injection amount command value becomes gradual, and the output characteristics of the diesel engine also become gradual accordingly.Thus, even when the accelerator opening increases sharply, the output torque fluctuation is suppressed. You.

Here, the final injection amount command value is calculated based on the smaller of the basic injection amount command value and the maximum injection amount command value except at the time of starting, and the basic injection amount command value is It is calculated based on the smaller of the governor pattern injection amount command value calculated based on the accelerator opening, the engine speed, and the like, or the final injection amount command value subjected to the smoothing process. The maximum injection amount command value is requested by the driver (corresponding to the accelerator opening).
This is a control upper limit value for the basic injection amount command value.

In a conventional diesel engine control device, as described in Japanese Patent Application Laid-Open No. 2-305336, one of the exhaust gas discharged from a combustion chamber into an exhaust passage to suppress NOx in the exhaust gas. An exhaust gas recirculation device (EGR) that recirculates the section through the intake passage to the combustion chamber. In the control device for a diesel engine having such an EGR, when the difference between the maximum injection amount command value and the final injection amount command value is smaller than a predetermined EGR determination command value, the process of stopping the operation of the EGR is performed. Is running. For example, during acceleration when the final injection amount command value finally matches the maximum injection amount command value, the difference between the two becomes smaller than the EGR determination command value, and thus the EGR operation is stopped. As a result, the shortage of the intake air amount due to the exhaust gas recirculation is eliminated, and the amount of diesel smoke generated is suppressed.

However, even when the EGR stop signal is output to the EGR, the exhaust gas recirculation is not stopped immediately due to a response delay of the EGR and the amount of generated diesel smoke is sufficiently suppressed. It was hard to say. Therefore, as described in JP-A-2-305336, a process for reducing the maximum injection amount in accordance with the EGR stop signal is performed to compensate for the EGR response delay.

As described above, by reducing the maximum injection amount, the shortage of the intake air amount with respect to the injection amount supplied to the combustion chamber by the fuel injection pump is eliminated, and the N in the exhaust gas is reduced.
Ox and the amount of diesel smoke generated can be suppressed. In such a control device for a diesel engine in which the maximum injection amount reduction process is performed, the difference between the maximum injection amount command value and the final injection amount command value is smaller than a predetermined EGR determination command value, and When the injection amount is being reduced, the operation of the EGR is stopped.

[0007]

However, in the conventional diesel engine control device, since the smoothing process is always performed based on the final injection amount command value, the maximum injection amount command value, the basic injection amount command value, The size relations frequently changed. In addition, the difference between the maximum injection amount command value and the final injection amount command value for stopping EGR is determined by a predetermined EGR value.
The EGR operation is performed when the reduction of the maximum injection amount is completed, even though the diesel engine is in the non-exhaust gas recirculation region, since the execution is performed when the injection amount is smaller than the determination command value and the maximum injection amount is being reduced. Was.

[0008] Therefore, the repetition of the operation signal and the stop signal for the EGR causes the EGR control valve to repeatedly open and close, thereby deteriorating the reliability of the EGR control valve. Was. Also,
There is a problem that the EGR is activated in a region where the maximum injection amount command value is selected as the final injection amount command value, and the amount of diesel smoke generated due to the shortage of the intake air amount increases. Further, there is a problem that the output torque fluctuates due to the fluctuation of the internal EGR amount due to the repeated opening and closing of the EGR control valve.

These problems will be described with reference to a timing chart shown in FIG. Here, FIG. 10 shows each injection command value during acceleration (basic injection amount command value QBAS
E, maximum injection amount command value QFULL, final injection amount command value Q
FIN), the accelerator opening, the engine speed, and the EGR duty value DEFIN.

Until the basic injection amount command value reaches the maximum injection amount command value, the basic injection amount command value is adopted as the final injection amount command value. The smoothing process is performed based on the basic injection amount command value. On the other hand, when the basic injection amount command value reaches the maximum injection amount command value, the maximum injection amount command value is adopted as the final injection amount command value, and the difference between the maximum injection amount command value and the final injection amount command value is Extremely small and DEFI
Since 0 is output as N, the EGR shifts from the operating state to the stopped state.

[0011] With the transition from the operating state to the stop state of the EGR, the decrease correction of the maximum injection amount command value is executed instantaneously, and the maximum injection amount command value temporarily drops. Therefore,
The acceleration smoothing process performed based on the final injection amount command value (basic injection amount command value) is performed based on the maximum injection amount command value, and is smoother than the governor pattern injection amount command value. The processed maximum injection amount command value becomes smaller. As a result, the maximum injection amount command value subjected to the smoothing process is adopted as the basic injection amount command value, and the basic injection amount command value follows the change of the maximum injection amount command value.

The reduction correction for the maximum injection amount command value is eventually changed, and the maximum injection amount command value starts increasing and becomes larger than the basic injection amount command value. As a result, the basic injection amount command value is adopted as the final injection amount command value, and a difference occurs between the maximum injection amount command value and the final injection amount command value.
When the GR stop condition is not satisfied and the EGR map corresponds to the EGR operation region, the EGR is operated again.

However, when the maximum injection amount command value exceeds the basic injection amount command value, the basic injection amount command value is adopted as the final injection amount command value. It will be performed based on the value. Then, under the condition that the accelerator opening is still large (in an acceleration state), the basic injection amount command value reaches the maximum injection amount command value again, and the final injection amount command value adopts the maximum injection amount command value. As a result, the EGR stop condition is restored, the decrease correction of the maximum injection amount command value is executed, the maximum injection amount drops again, and the basic injection amount instruction value becomes larger than the maximum injection amount instruction value.

Thereafter, by repeating the above series of changes, the operation and stop of the EGR are repeated. The repetition of the operation / stop of the EGR is performed by first stopping the EGR when the difference between the maximum injection amount command value and the final injection amount command value is:
Smaller than a predetermined EGR determination command value, and
This is caused by executing the stop of the EGR when the maximum injection amount is being reduced.

Second, even after the final injection amount command value employs the maximum injection amount command value not based on the accelerator opening, acceleration smoothing processing is performed based on the final injection amount command value (maximum injection amount command value). Is caused by the fact that the magnitude relationship between the maximum injection amount command value and the basic injection amount command value frequently changes.

Third, even if the final injection amount command value employs the maximum injection amount command value not based on the accelerator opening, the smoothing process during acceleration is continued. This is caused by the frequent occurrence of a change in the magnitude relationship between the values.

The above-mentioned problems occur due to these three reasons. The present invention has been made in order to solve the above-mentioned conventional problems.The present invention prevents frequent activation and stop of the exhaust gas recirculation means, suppresses output torque fluctuations, and reduces the amount of diesel smoke generated. The purpose is to control.

[0018]

According to a first aspect of the present invention, there is provided a control apparatus for a diesel engine, comprising: a fuel injection pump M3 for supplying fuel to a combustion chamber M2 of a diesel engine M1; , The diesel engine M1
Operating state detecting means M4 for detecting the operating state of
Governor pattern injection amount calculation means M5 for calculating a governor pattern injection amount based on the engine speed, accelerator opening, and the like detected by the operation state detection means M4, and an operation state detected by the operation state detection means M4 The engine acceleration state determining means M6 for determining whether or not the diesel engine M1 is in an acceleration state based on the
Is determined to be in an accelerated state, the acceleration smoothing injection amount calculating means M7 for calculating the acceleration smoothing injection amount based on the previously calculated basic injection amount required for the fuel injection pump M3, If the engine acceleration state determination means M6 determines that the diesel engine M1 is in an accelerated state, the basic injection amount is determined based on the smaller injection amount of the governor pattern injection amount or the accelerated smoothing injection amount. A basic injection amount calculating means M8 for calculating
A maximum injection amount calculation unit M9 for calculating a maximum injection amount based on the intake pressure detected by the operating state detection unit M4, and the maximum injection amount based on the smaller injection amount of the basic injection amount or the maximum injection amount. Fuel injection pump M3
The final injection amount calculating means M10 for calculating the final injection amount to be finally supplied to the combustion chamber M2, and the difference between the maximum injection amount and the final injection amount is determined by the operating state detecting means M4. If the exhaust gas recirculation determination amount is larger than the exhaust gas recirculation determination amount calculated based on the detected operation state, the exhaust gas recirculation region determining means M11 that determines that the diesel engine M1 is in the exhaust gas recirculation region; When the determination means M11 determines that the diesel engine M1 is in the exhaust gas recirculation region, a part of the exhaust gas discharged from the combustion chamber M2 is used for the combustion chamber M2.
Whether the diesel engine M1 is in a transition state from the exhaust gas recirculation area to the non-exhaust gas recirculation area based on the result determined by the exhaust gas recirculation means M12 for recirculating the exhaust gas and the result determined by the exhaust gas recirculation area determining means M11. The engine transient state determining means M13 for determining whether or not the diesel engine M1
Is determined to be in a transition state from the exhaust gas recirculation region to the non-exhaust gas recirculation region, a maximum injection amount correcting means M14 for reducing the maximum injection amount for a predetermined period is provided.

Further, the control apparatus for a diesel engine according to the second aspect of the present invention includes a combustion chamber M of the diesel engine M1.
A fuel injection pump M3 for supplying fuel to the engine 2, an operating state detecting means M4 for detecting an operating state of the diesel engine M1, an engine speed and an accelerator opening detected by the operating state detecting means M4. The governor pattern injection amount calculating means M5 for calculating the governor pattern injection amount based on the above and the like, and whether or not the diesel engine M1 is in an accelerating state is determined based on the operating state detected by the operating state detecting means M4. When the diesel engine M1 is determined to be in an accelerated state by the engine acceleration state determination means M6 and the engine acceleration state determination means M6, the fuel injection pump M3 calculated last time finally determines the combustion state. Acceleration smoothing injection amount calculating means M15 for calculating an acceleration smoothing injection amount based on the final injection amount to be supplied to the chamber M2; When the engine acceleration state determination means M6 determines that the diesel engine M1 is in an accelerated state, and when the basic injection amount is larger than the maximum injection amount, only the governor pattern injection amount is used. A basic injection amount calculating means M16 for calculating the basic injection amount, a maximum injection amount calculating means M9 for calculating a maximum injection amount based on the intake pressure and the like detected by the operating state detecting means M4, A final injection amount calculating means M10 for calculating a final injection amount to be finally supplied to the combustion chamber M2 by the fuel injection pump M3 based on the smaller injection amount of the basic injection amount or the maximum injection amount; An exhaust gas recirculation calculated based on an operation state detected by the operation state detection means M4, wherein a difference between the maximum injection amount and the final injection amount is calculated. If greater than the cross-sectional volume, the diesel engine M1 is an exhaust gas recirculation region determining means M11 for determining that there is an exhaust gas recirculation region,
If the exhaust gas recirculation area determining means M11 determines that the diesel engine M1 is in the exhaust gas recirculation area, a part of the exhaust gas discharged from the combustion chamber M2 is recirculated to the combustion chamber M2. It is determined whether or not the diesel engine M1 is in a transition state from the exhaust gas recirculation region to the non-exhaust gas recirculation region based on the result determined by the exhaust gas recirculation unit M12 and the exhaust gas recirculation region determination unit M11. Transient state determining means M1 for determining
3, when the engine transient state determination means M13 determines that the diesel engine M1 is in a transition state from the exhaust gas recirculation region to the non-exhaust gas recirculation region, the maximum injection amount is reduced for a predetermined period. And the maximum injection amount correcting means M14.

Further, the control apparatus for a diesel engine according to the present invention detects a fuel injection pump M3 for supplying fuel to a combustion chamber M2 of the diesel engine M1, and detects an operation state of the diesel engine M1. Operating state detecting means M4, an governor pattern injection amount calculating means M5 for calculating a governor pattern injection amount based on an engine speed, an accelerator opening, and the like detected by the operating state detecting means M4; Engine acceleration state determination means M6 for determining whether or not the diesel engine M1 is in an acceleration state based on the operation state detected by the state detection means M4, and the diesel engine M1 is determined by the engine acceleration state determination means M6. When it is determined that the combustion chamber is in the accelerated state, the combustion chamber M3 calculated last time is finally used as the combustion chamber. The acceleration smoothing injection amount calculating means M15 for calculating the acceleration smoothing injection amount based on the final injection amount to be supplied to the engine 2 and the engine acceleration state determining means M6 determine that the diesel engine M1 is in an accelerated state. In this case, the basic injection amount calculating means M8 for calculating the basic injection amount based on the smaller injection amount of the governor pattern injection amount or the acceleration smoothing injection amount.
A maximum injection amount calculating unit M9 for calculating a maximum injection amount based on the intake pressure detected by the operating state detecting unit M4, and an injection amount smaller than the basic injection amount or the maximum injection amount. A final injection amount calculating means M10 for calculating a final injection amount to be finally supplied to the combustion chamber M2 by the fuel injection pump M3 based on the fuel injection pump M3.
When the difference between the maximum injection amount and the final injection amount is larger than the exhaust gas recirculation determination amount calculated based on the operation state detected by the operation state detection unit M4,
When the exhaust gas recirculation region determining means M11 that determines that the diesel engine M1 is in the exhaust gas recirculation region and the exhaust gas recirculation region determining device M11 determines that the diesel engine M1 is in the exhaust gas recirculation region, ,
Exhaust gas recirculation means M12 for recirculating a part of the exhaust gas discharged from the combustion chamber M2 to the combustion chamber M2
Engine transient state determination for determining whether the diesel engine M1 is in a transition state from the exhaust gas recirculation area to the non-exhaust gas recirculation area based on the result determined by the exhaust gas recirculation area determination means M11. When the means M13 and the engine transient state determination means M13 determine that the diesel engine M1 is in a transition state from the exhaust gas recirculation region to the non-exhaust gas recirculation region, the maximum injection amount is reduced for a predetermined period. Injection amount correction means M14 for
When the exhaust gas recirculation area determining means M11 determines that the diesel engine M1 is not in the exhaust gas recirculation area, or when the maximum injection amount is reduced by the maximum injection amount correction means M14, Exhaust gas recirculation prohibition means M17 for prohibiting recirculation of exhaust gas by the exhaust gas recirculation means M12.

[0021]

In the control apparatus for a diesel engine according to the first aspect of the present invention, fuel is supplied to the combustion chamber M2 of the diesel engine M1 by the fuel injection pump M3, and the diesel engine is operated by the operating state detecting means M4. M1
Is detected.

The governor pattern injection amount calculating means M5 calculates the governor pattern injection amount based on the engine speed, accelerator opening, and the like detected by the operating state detecting means M4. When the engine acceleration state determination means M6 determines that the diesel engine M1 is in an acceleration state, the acceleration smoothing injection amount calculation means M7 calculates the basic injection amount required for the fuel injection pump M3 calculated last time. Calculates the acceleration smoothing injection amount based on. Then, the basic injection amount calculating means M8
When the engine acceleration state determination means M6 determines that the diesel engine M1 is in an accelerated state, the fuel injection pump M3 is controlled based on the smaller of the governor pattern injection amount and the accelerated smoothing injection amount. To calculate the required basic injection quantity.

The maximum injection amount calculating means M9 calculates the maximum injection amount based on the intake pressure detected by the operating state detecting means M4. In addition, the final injection amount calculation means M10
Based on the smaller injection amount of the basic injection amount or the maximum injection amount, the fuel injection pump M3 finally ends the combustion chamber M
2 to calculate the final injection quantity to be supplied.

When the difference between the maximum injection amount and the final injection amount is smaller than the exhaust gas recirculation determination amount calculated based on the operation state detected by the operation state detection means M4, It is determined that the diesel engine M1 is in the exhaust gas recirculation area. When the exhaust gas recirculation area determining means M11 determines that the diesel engine M1 is in the exhaust gas recirculation area, the exhaust gas recirculation means M12 transfers a part of the exhaust gas discharged from the combustion chamber M2 to the combustion chamber M2. Recirculate. The maximum injection amount correction means M14 determines the maximum injection amount by a predetermined amount when the engine transient state determination means M13 determines that the diesel engine M1 is in a transition state from the exhaust gas recirculation region to the non-exhaust gas recirculation region. Reduce the period.

Therefore, the basic injection amount is always calculated based on the smaller injection amount of the acceleration smoothing injection amount or the governor pattern injection amount calculated based on the basic injection amount. Even though it is not affected.

In the control apparatus for a diesel engine according to the second aspect of the present invention, the acceleration smoothing injection amount calculating means M
A step 15 calculates an accelerated smoothing injection amount based on a previously calculated final injection amount to be finally supplied to the combustion chamber M2 by the fuel injection pump M3. If the basic injection amount is larger than the maximum injection amount, the basic injection amount calculation means M16 calculates the basic injection amount based only on the governor pattern injection amount.

Therefore, the basic injection amount does not use the maximum injection amount that fluctuates without reflecting the accelerator opening as a calculation parameter, and once the basic injection amount exceeds the maximum injection amount, the maximum injection amount is once again increased. Does not exceed the basic injection amount, the output torque fluctuation is suppressed, and the repetition of recirculation / stop of exhaust gas by the exhaust gas recirculation means M12 is suppressed.

Further, in the control apparatus for a diesel engine according to the third aspect of the present invention, the acceleration smoothing injection amount calculating means M15 is finally supplied to the combustion chamber M2 by the fuel injection pump M3 calculated last time. The acceleration smoothing injection amount is calculated based on the final injection amount to be performed. The exhaust gas recirculation prohibiting means M17 is provided when the exhaust gas recirculation area determination means M11 determines that the diesel engine M1 is not in the exhaust gas recirculation area, or when the maximum injection amount is reduced by the maximum injection amount correction means M14. If so, prohibit exhaust gas recirculation.

Therefore, the exhaust gas is not recirculated by the exhaust gas recirculation means M12, and the final injection amount is maximized even though the exhaust gas recirculation means M12 has completed the reduction period of the maximum injection amount despite the fact that it is in the non-exhaust gas recirculation region. Exhaust gas recirculation in the state calculated based on the injection amount is prevented.

[0030]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Several embodiments of the present invention applied to a control device for a diesel engine will be described below with reference to the drawings.

First, the configuration of the control device DC1 for the diesel engine according to the first embodiment will be described with reference to FIG. FIG. 2 is a schematic configuration diagram showing a supercharged diesel engine system to which the present embodiment is applied.

The diesel engine system includes a diesel engine 10 as an internal combustion engine, and a fuel injection pump 40 for pumping fuel toward the diesel engine 10.

The diesel engine 10 and the fuel injection pump 40 are drivingly connected by mounting a belt or the like on a crankshaft 14 (described later) of the diesel engine 10 and a drive pulley 41 (described later) of the fuel injection pump 40. Have been. And the diesel engine 10
Is started, and the drive pulley 41 rotates to drive the fuel injection pump 40, and the fuel passage 19 (described later)
The fuel is pumped to the diesel engine 10 via the.

The configuration of the diesel engine 10 will be described. The diesel engine 10 includes a cylinder block 11 in which a plurality of cylinders are formed, a cylinder head 12 connected to an upper portion of the cylinder block 11, and a piston 13 that reciprocates up and down in each cylinder of the cylinder block 11. ing. A crankshaft 14 is connected to a lower end of the piston 13.
4 is rotated. Further, in the vicinity of the crankshaft 14, a reference position of rotation of the crankshaft 14, for example, the crankshaft 1 corresponding to the top dead center of the specific cylinder
4 is provided with a crank angle sensor 80 for detecting the rotational position.

The space defined by the inner wall of each cylinder block 11, the cylinder head 12, and the top of the piston 13 functions as a main combustion chamber 15 for main combustion of the air-fuel mixture. In addition, each cylinder block 11
The cylinder head 12 has an intake port 16, an exhaust port 17, and a sub-combustion chamber 18 for pre-combustion of an air-fuel mixture corresponding to each cylinder. It communicates with the chamber 15. Further, each sub combustion chamber 18 is provided with a fuel injection nozzle 20 connected to a fuel injection pump via a fuel passage 19, and a glow plug 21 as a starting assist device. A water temperature sensor 8 for detecting the temperature (cooling water temperature) THW of the cooling water flowing through the cooling water passage is provided in the cylinder block 11.
1 is provided.

An intake pipe 22 and an exhaust pipe 23 are respectively connected to the intake port 16 and the exhaust port 17 of the cylinder head 12, and a compressor 25 of a turbocharger 24 is disposed in the intake pipe 22. Is provided with a turbine 26 of a turbocharger 24.
An air cleaner 27 is attached to the end of the intake pipe 22, and an intake air temperature sensor 82 that detects the intake air temperature of the intake air is provided in the intake pipe 22 near the air cleaner 27. Further, a waste gate valve 28 for adjusting the supercharging pressure obtained by the turbocharger 24 is attached to the exhaust pipe 23.
The intake port 16 is provided with an intake pressure sensor 83 for detecting the intake pressure in the intake port 16.

The exhaust pipe 23 and the intake port 16 are connected by a recirculation pipe 29 for recirculating a part of the exhaust gas in the exhaust pipe 23 to the intake port 16. And the reflux pipe 29
EGR valve 3 for adjusting the amount of exhaust gas recirculation
The EGR valve 30 is controlled to open and close by control of a vacuum switching valve (VSV 31).

Further, a throttle valve 33 that opens and closes in conjunction with the depression amount of an accelerator pedal 32 is provided in the middle of the intake pipe 22. Near the throttle valve 33, an opening / closing position of the throttle valve 33 is provided. Opening ACCP corresponding to the load of diesel engine 10
Is provided with an accelerator opening sensor 84 for detecting the acceleration.

An axle (not shown) is connected to a reed switch 85b by a magnet 85a provided on the axle.
Vehicle speed (vehicle speed) SPD by turning on / off
A vehicle speed sensor 85 for detecting the vehicle speed is provided.

Next, the configuration of the fuel injection pump 40 will be described. The fuel injection pump 40 includes a drive pulley 41 for driving the fuel injection pump 40 by the transmitted driving force of the diesel engine 10, and a drive shaft 42 is connected to the drive pulley 41. Then, approximately in the center of the drive shaft 42,
A fuel feed pump 43 (developed at 90 degrees in the figure) composed of a vane type pump is provided, and a disk-shaped pulsar 44 having a plurality of projections on the outer peripheral surface is attached near the base end of the drive shaft 42. Have been. A cam plate 45 on which a cam face 46 is formed is connected to a base end (right end in the drawing) of the drive shaft 42 via a coupling (not shown).

A roller ring 47 is provided between the pulsar 44 and the cam plate 45.
A plurality of cam rollers 48 facing the cam face 46 of the cam plate 45 are attached to the side of the cam plate 45 facing the cam plate 45. In addition, on the upper part of the roller ring 47,
A rotation speed sensor 86 composed of an electromagnetic pickup coil is mounted to face the outer peripheral surface of the pulser 44, and outputs a pulse signal corresponding to the engine rotation speed NE as the protrusion of the pulser 44 passes. Then, the cam plate 45
Is always urged and engaged with the cam roller 48 by a spring 49 provided on the side where the cam face 46 is not formed.

A fuel pressurizing plunger 50 is mounted on the side of the cam plate 45 where the cam face 46 is not formed so as to be integrally rotatable. The cam plate 45 rotates as the drive shaft 42 rotates, and the cam face 46 is moved. By engaging with the cam roller 48, the cam plate 4
5 and the plunger 50 are reciprocally driven in the left and right directions in the figure while rotating.

The plunger 50 includes a pump housing 51
Are formed on the outer periphery of the distal end side (right end side in the figure) of which the number of intake grooves 56 and distribution ports 57 are the same as the number of cylinders of the diesel engine 10. The space between the tip end surface (right end side in the figure) of the plunger 50 and the inner bottom surface of the cylinder 52 functions as a high-pressure chamber 53.

The pump housing 51 has a fuel supply port 5 connected to a fuel tank (not shown) through a fuel passage (not shown) near the fuel feed pump 43.
4 has a fuel chamber 55 above the plunger 50. The pump housing 51 has a suction groove 56.
In addition, a suction port 58 and a distribution passage 59 corresponding to the distribution port 57, and a spill passage 60 for fuel overflow that communicates the high-pressure chamber 53 with the fuel chamber 55 are formed. An electromagnetic spill valve 61 for adjusting the amount is provided.

The electromagnetic spill valve 61 is a normally-open type valve, and when the coil 62 is not energized (off),
The valve body 63 is opened, and the fuel in the high-pressure chamber 53 is released from the fuel chamber 55.
Overflows to On the other hand, when the coil 62 is energized (ON), the valve body 63 is closed and the overflow from the high-pressure chamber 53 to the fuel chamber 55 is stopped.

Also, on the lower side of the pump housing 51,
A timer device 64 for fuel injection timing control (developed at 90 degrees in the figure) is provided. This timer device 64
By controlling the position of the roller ring 47 with respect to the rotation direction of the drive shaft 42, the cam face 4
This is a device for controlling the timing at which the cam 6 engages with the cam roller 48, that is, the reciprocating timing of the cam plate 45 and the plunger 50.

The timer device 64 is fitted in the timer housing 65, and the timer piston 66 connected to the roller ring 47 via the slide pin 65a and the fuel pressurized by the fuel feed pump 43 are used for the timer device 64. The pressurized chamber 67a to be introduced (timer housing 6 in the figure)
5) and a low-pressure chamber 67b (left space in the timer housing 65 in the figure). In addition, the timer device 64 is disposed in the middle of the communication passage 68, which communicates between the pressure chamber 67a and the low-pressure chamber 67b, and the timer spring 66a for urging the timer piston 66 toward the pressure chamber 67a. Equipped with a timing control valve.

The timing control valve 69 is an electromagnetic valve whose opening and closing are controlled by a duty-controlled energizing signal. The opening and closing of the timing control valve 69 controls the fuel pressure in the pressurizing chamber 67a.

Next, the operation of the fuel injection pump 40 having the above-described configuration will be described with reference to the flow of fuel. The rotation of the drive shaft 42 causes the fuel feed pump 43
Is driven, the fuel in the fuel tank is supplied to the fuel chamber 55 via the fuel supply port 54. In the suction stroke in which the plunger 50 moves to the left in the drawing (returns) and the high-pressure chamber 53 is depressurized, one of the suction grooves 56 communicates with the suction port 58 in the fuel supplied to the fuel chamber 55. It is introduced into the high pressure chamber 53. In contrast, plunger 5
In the compression stroke in which 0 moves to the right in the drawing (forward movement) and the high-pressure chamber 53 is pressurized, the fuel supplied to the fuel chamber 55 is pressure-fed from the distribution passage 59 to the fuel injection nozzle 20 for each cylinder. Then, the fuel is injected into the sub-combustion chamber 18.

By opening the electromagnetic spill valve 61 during the compression stroke, the fuel pressure in the high-pressure chamber 53 is reduced, and the fuel injection from the fuel injection nozzle 20 to the combustion chamber is stopped. Therefore, by controlling the valve opening / closing timing of the electromagnetic spill valve 61 during the forward movement of the plunger 50, the fuel injection amount from the fuel injection nozzle 20 is adjusted.

The forward movement start timing of the plunger 50 is adjusted by adjusting the opening / closing timing of the timing control valve 69 of the timer device 64 and adjusting the fuel pressure to the pressurizing chamber 67a.

Next, a control system of the control device DC1 of the diesel engine according to the present embodiment will be described with reference to a control block diagram shown in FIG. Diesel engine control unit D
The control system of C1 is an electronic control unit 70 (hereinafter referred to as “EC
U ". ) At the core. And E
The governor pattern calculating means, the engine acceleration state determining means, the acceleration smoothing injection amount calculating means, the basic injection amount calculating means, the maximum injection amount calculating means, the final injection amount calculating means, the exhaust gas recirculation area determining means, the engine transient state determining by the CU 70 , A maximum injection amount correcting means and the like are realized.

The ECU 70 always sets the basic injection amount command value QB
Various control programs such as a first injection amount calculation program for calculating an acceleration smoothing injection amount command value QSMA based on ASE, and various correction terms, base EGR duty DEBSE, etc. are calculated based on the detection values detected by the sensors. ROM 71 which stores a map for storing.

The ECU 70 executes a CP for executing an arithmetic process based on a control program stored in the ROM 71.
U72, RAM 73 and RAM 7 for temporarily storing the calculation results of CPU 72, data input from each sensor, and the like.
3 is provided with a backup RAM 74 for holding various data stored when the power supply is stopped.

Then, the CPU 72, the ROM 71, and the RAM
73 and a backup RAM 74 include a bidirectional bus 75
And the input interface 76 and the output interface 77. The input interface 76 includes a crank angle sensor 80, a water temperature sensor 81, an intake air temperature sensor 82, an intake air pressure sensor 83, an accelerator opening sensor 84, a vehicle speed sensor 8
5. The rotation speed sensor 86 and the like are connected. If the signal output from each sensor is an analog signal, the signal is converted into a digital signal by an A / D converter (not shown) and then output to the bidirectional bus 75.

External circuits such as the glow plug 21, the VSV 31, the electromagnetic spill valve 61, and the timing control valve 69 are connected to the output interface 77. These external circuits operate the control program executed by the CPU 72. The operation is controlled based on the result.

Next, regarding the first injection amount calculation program in the diesel engine control device DC1 according to the first embodiment having the above-described configuration, refer to the flowchart of the first injection amount calculation program as the main routine shown in FIG. I will explain.

Here, the first injection amount calculation program is a program for always calculating the acceleration smooth injection amount command value QSMA based on the basic injection amount command value QBASE when the diesel engine 10 is accelerating. is there. In addition,
“S” in the flowchart of each program indicates each step.

In S100, the engine speed NE output from the speed sensor 86, the accelerator opening ACCP output from the accelerator opening sensor 84, the intake pressure sensor 8
The ECU 70 reads the intake pressure VPIM output from the ECU 3 into the ECU 70.

In step S110, the maximum injection amount command value QFUL is obtained by the subroutine maximum injection amount calculation program.
Calculate L. The maximum injection amount calculation program will be described with reference to the flowchart of the maximum injection amount calculation program shown in FIG.

In S1100, based on the map in the ROM 71, the maximum injection amount command value offset term QFULO and the maximum injection amount command value intake pressure correction coefficient QFULB corresponding to the engine speed NE read in S100 are calculated.
In subsequent S1105, based on the map in the ROM 71,
An intake pressure correction coefficient MQFPB corresponding to the intake pressure VPIM read at 100 is calculated.

At S1110, the EGR valve 30 (VS
V31) is operating, whether the EGR valve 30
The determination is made based on whether or not the final EGR duty DEFIN output for (VSV31) is zero.

As a result of the determination, the final EGR duty DEF
If it is determined that IN is not 0, that is, if it is determined that the EGR valve 30 (VSV31) is operating (S1110: YES), it is determined whether the EGR flag XEGR is set (S1115). . If it is determined that the EGR flag XEGR is set (S1115: YES), the process proceeds to S11
Move to 40. On the other hand, when it is determined that the EGR flag XEGR has been reset (S1115: N
O), after setting the EGR flag XEGR in S1120, the process proceeds to S1140.

On the other hand, the final EGR duty DE
When it is determined that FIN is 0, that is, when it is determined that the EGR valve 30 (VSV31) is not operating (S1120: NO), it is determined whether the EGR flag XEGR is reset (S1125). ).
If it is determined that EGR flag XEGR has been reset (S1125: YES), the process proceeds to S1140. On the other hand, when it is determined that the EGR flag XEGR is set (S1125: N
O), the EGR flag XEGR is reset in S1130, and the predetermined value A is stored in the transient intake pressure correction term MQFPT in S1135, and then the step moves to S1140. The initial value of the transient intake pressure correction term MQFPT is 0.
It is assumed that

At S1140, the intake pressure correction coefficient MQFP
By subtracting the transient intake pressure correction term MQFPT from B, a maximum injection amount command value intake pressure correction term MQFP is calculated. In subsequent S1145, it is determined whether or not the maximum injection amount command value intake pressure correction term MQFP is equal to or greater than the intake pressure correction coefficient MQFPB.

Then, the maximum injection amount command value intake pressure correction term M
If it is determined that QFP is equal to or greater than the intake pressure correction coefficient MQFPB (S1145: YES), the intake pressure correction coefficient MQFPB is set as the maximum injection amount command value intake pressure correction term MQFP.
Is stored (S1150), and the transient intake pressure correction term MQF
After storing 0 in PT (S1155), the step is S
It moves to 1165.

On the other hand, when it is determined that the maximum injection amount command value intake pressure correction term MQFP is smaller than the intake pressure correction coefficient MQFPB (S1145: NO), the transient intake pressure correction term MQFPT is included in the transient intake pressure correction term MQFPT. After storing the value obtained by subtracting the predetermined value B from the atmospheric pressure correction term MQFPT (S1160), the process proceeds to S1165.

In S1165, the maximum injection amount command value intake pressure correction term M is added to the maximum injection amount command value intake pressure correction coefficient QFULB.
QFP multiplied by the maximum injection quantity command value offset term Q
By adding FULO, the maximum injection amount command value QF
Calculate the ULL. Then, the step returns to the main routine.

In the main routine, the governor pattern injection amount command value QGOV corresponding to the accelerator opening ACCP detected by the accelerator opening sensor 84 and the engine speed NE detected by the speed sensor 86 based on the map of the ROM 71. Is calculated (S120).

In S130, it is determined whether or not the governor pattern injection amount command value QGOV is equal to or more than the last calculated final injection amount command value before cylinder correction QFINAOL (precisely, the last final injection amount command value QFIN). . That is, the injection amount command value required by the driver (that is, the governor pattern injection amount command value QGOV) is equal to or greater than the last injection amount command value QFIN which was finally supplied to the diesel engine 10 by the fuel injection pump 40 last time. By determining whether or not there is, it is determined whether or not the diesel engine 10 is in an accelerated state (whether or not the driver wants to accelerate).

Then, the governor pattern injection amount command value QG
OV is the last calculated final injection amount command value QF before cylinder correction
When it is determined that the engine speed is equal to or more than INAOL, that is, when it is determined that the diesel engine 10 is in an accelerating state (the driver desires acceleration) (S130: YE
S), an acceleration smoothing injection amount command value QSMA for suppressing sudden output torque fluctuation during acceleration is calculated (S).
140). This accelerated annealing injection amount command value QSMA is different from the previously calculated basic injection amount command value QBASEOL.
It is calculated by performing an accelerated annealing process. Specifically, the previously calculated basic injection amount command value QBASEOL
Is calculated by adding the acceleration smoothing amount MQSMAD calculated from the map of the ROM 71 based on the accelerator opening ACCP and the engine speed NE.

In the following S150, the governor pattern injection amount command value QGOV or the acceleration smoothing injection amount command value QSM
A smaller injection amount command value of A is stored as a basic injection amount command value QBASE. Here, when the diesel engine 10 is in an accelerating state, usually, the acceleration smoothing injection amount command value QSMA is smaller than the governor pattern injection amount command value QGOV, and the acceleration smoothing injection amount command value QSMA is equal to the basic injection amount. Stored as the quantity command value QBASE. Then, the step shifts to S180.

On the other hand, when it is determined that the governor pattern injection amount command value QGOV is less than the previously calculated pre-cylinder correction final injection amount command value QFINAOL, that is, it is determined that the diesel engine 10 is in a deceleration state. In this case (S130: NO), the deceleration smoothing injection amount command value QS for suppressing the fluctuation of the output torque during deceleration is set.
The MD is calculated (S160). The deceleration smoothed injection amount command value QSMD is obtained by adding the previously calculated final injection amount command value before cylinder correction QFINAOL to the deceleration smoothing amount calculated from the map in the ROM 71 based on the accelerator opening ACCP and the engine speed NE. It is calculated by adding MQSMDD.

At S170, the governor pattern injection amount command value QGOV or the deceleration smoothing injection amount command value QSM
The larger injection amount command value of D is stored as the basic injection amount command value QBASE. Here, when the diesel engine 10 is in the deceleration state, the deceleration smoothing injection amount command value QSMD is usually larger than the governor pattern injection amount command value QGOV, and the deceleration smoothing injection amount command value QSMD is the basic injection. Stored as the quantity command value QBASE. Then, the step shifts to S180.

At S180, the maximum injection amount command value QFUL
The smaller of L and the basic injection amount command value QBASE is stored as the pre-cylinder correction final injection amount command value QFINA. In the first embodiment, the acceleration smoothing injection amount command value QSMA is always calculated by performing the acceleration smoothing process on the previous basic injection amount command value QBASEOL, so that the maximum injection amount command value QFULL A pre-cylinder correction final injection amount command value QFINA that is not affected by the magnitude relationship with the basic injection amount command value QBASE is obtained.

Then, at S190, the final injection amount command value Q
FIN is calculated, an injection amount command signal is output to the fuel injection pump 40, and this program ends. Note that the final injection amount command value QFIN calculated this time is used as an updated value of the last pre-cylinder correction final injection amount command value QFINAOL by the last final injection amount command value storage program shown in FIG.

At S200, the engine speed counter C
It is determined whether the NIRQ counter value is the fuel injection end timing, for example, 13 or not. And
When it is determined that the counter value is 13, (S20
0: YES), the final injection amount command value QFI calculated this time
N, the last injection amount command value before final cylinder correction QFIN
The AOL is updated (S210). On the other hand, if the counter value is 1
When it is determined that it is not 3 (S200: NO), the last injection amount command value before final cylinder correction QFINAOL is not updated.

Next, a control device DC2 for a diesel engine according to a second embodiment will be described. The control device DC2 for the diesel engine according to the second embodiment stops the acceleration smoothing process when the basic injection amount command value QBASE is larger than the maximum injection amount command value QFULL, instead of the first injection amount calculation program. The second injection amount calculation program is stored in the ROM 7
1 is different from the control device DC1 for the diesel engine according to the first embodiment, and the other components are the same.

Hereinafter, the second injection amount calculation program will be described with reference to the flowchart of the second injection amount calculation program shown in FIG. Here, the second injection amount calculation program prevents the frequent operation of the EGR valve 30 by stopping the acceleration smoothing process when the basic injection amount command value QBASE is larger than the maximum injection amount command value QFULL. It is a program. Steps S300 to S370 are performed in step S200 of the first injection amount calculation program.
Since each step almost corresponds to steps S270 to S270,
This will be briefly described.

First, at S300, the ECU 70 calculates the engine speed NE output from the speed sensor 86, the accelerator opening ACCP output from the accelerator opening sensor 84, and the intake pressure VPIM output from the intake pressure sensor 83.
Perform a read to. Then, in S310, a maximum injection amount command value QFULL is calculated by a maximum injection amount calculation program which is a subroutine. In S320, the engine speed NE, the accelerator opening ACCP, and the ROM 7 are calculated.
1 based on the governor pattern injection amount command value QGO
Calculate V.

In the following S330, the governor pattern injection amount command value QGOV is changed to the last cylinder correction last injection amount command value QF before cylinder correction.
It is determined whether or not INA or more. If the governor pattern injection amount command value QGOV is equal to or greater than the last cylinder correction last injection amount command value QFINAOL (S33).
0: YES), the last pre-cylinder correction final injection amount command value QFI
After performing acceleration smoothing processing on the NAOL, the acceleration smoothing injection amount command value QSMA is calculated (S340), and the basic injection amount command value QBASE is calculated (S350).
The step moves to S380.

On the other hand, the governor pattern injection amount command value QGOV is equal to the last cylinder correction last injection amount command value QFIN before cylinder correction.
If it is less than AOL (S330: NO), the deceleration smoothing injection amount command value QSMD is calculated (S360), and the basic injection amount command value QBASE is calculated (S370), and then the process proceeds to S370.

At S380, basic injection amount command value QBAS
It is determined whether E is larger than the maximum injection amount command value QFULL. When it is determined that the basic injection amount command value QBASE is larger than the maximum injection amount command value QFULL (S380: YES), the governor pattern injection is performed instead of the basic injection amount command value QBASE once calculated in S350. The amount command value QGOV is stored as the basic injection amount command value QBASE (S385), and the step moves to S390. Therefore, the acceleration smoothing process is not performed on the basic injection amount command value QBASE, and the basic injection amount command value QBASE is not affected by the variation of the maximum injection amount command value QFULL.

The basic injection amount command value QBASE is equal to S
Although calculated at 370, the basic injection amount command value QBASE is the basic injection amount command value QBASE for the diesel engine 10 under the deceleration state, and does not exceed the maximum injection amount command value QFULL.

On the other hand, the basic injection amount command value QBAS
If it is determined that E is equal to or less than the maximum injection amount command value QFULL (S380: NO), the basic injection amount command value QBA
The step moves to S390 without restoring the SE.

At S390, the maximum injection amount command value QFUL
The smaller of L and the basic injection amount command value QBASE is stored as the pre-cylinder correction final injection amount command value QFINA. Subsequently, in S395, the final injection amount command value QFI is determined based on the final injection amount command value QFINA before cylinder correction.
N is calculated, an injection amount command value is output to the fuel injection pump 40, and this program ends.

Next, a control unit DC3 for a diesel engine according to the third embodiment will be described. The control device DC3 for the diesel engine according to the third embodiment replaces the first injection amount calculation program with an exhaust gas recirculation prohibition processing program for prohibiting exhaust gas recirculation when the transient injection amount command value is being reduced. Is different from the control device DC1 for the diesel engine according to the first embodiment in that the ROM 71 has the same configuration, and the other components are the same.

Hereinafter, the exhaust gas recirculation prohibition processing program will be described with reference to the flowchart of the exhaust gas recirculation prohibition processing program shown in FIG. Here, the exhaust gas recirculation prohibition processing program is executed when the operation state of the diesel engine 10 is in the non-exhaust gas recirculation region or when the transient injection amount command value of the maximum injection amount command value QFULL is being reduced. This program prohibits exhaust gas recirculation.

First, in S400, it is determined whether or not the ignition signal is ON. That is, it is necessary to close the EGR valve 30 at the start of the start of the diesel engine 10. Therefore, if the ignition signal is O
If it is determined that it is FF (S400: NO), the step moves to S455 and the EGR final duty DEF
Store 0 in IN.

On the other hand, if it is determined that the ignition signal is ON (S400: YES), it is determined whether the starter signal is OFF (S405). And
If the starter signal is ON for the reason described above (S405: NO), the step moves to S455. On the other hand, if the starter signal is OFF (S405: YES), the step moves to S410.

At S410, the engine speed NE, the accelerator opening ACCP, the final injection amount command value QFIN, the water temperature T
The HW and the intake pressure VPIM are read into the ECU 70. Then, based on the map in the ROM 71, the EGR water temperature correction term NETHW corresponding to the water temperature THW is calculated (S415), and the EGR intake pressure correction term MEP corresponding to the intake pressure VPIM.
The calculation of IM (S420) is executed. ROM 71
The basic EGR duty DE corresponding to the engine speed NE and the final injection amount command value QFIN based on the map
The BSE is calculated (S425), and the EGR determination command value QEGR corresponding to the engine speed NE is calculated (S430). Here, the EGR determination command value QEGR is
This is a threshold value used to determine whether to open or close the valve 30.

In S435, the maximum injection amount command value QFUL
It is determined whether or not a value obtained by subtracting the pre-cylinder correction final injection amount command value QFINA from L is greater than an EGR determination command value QEGR. Here, generally, the basic injection amount command value QB
When the ASE is larger than the maximum injection amount command value QFULL, the maximum injection amount command value QFULL is adopted as the pre-cylinder correction final injection amount command value QFINA, so that the maximum injection amount command value QFULL and the pre-cylinder correction final injection amount are used. Command value QFI
The difference from NA becomes smaller.

If it is determined that the value obtained by subtracting the pre-cylinder correction final injection amount command value QFINA from the maximum injection amount command value QFULL is larger than the EGR determination instruction value QEGR (S435: YES), the process proceeds to step S440. Move to On the other hand, the maximum injection amount command value QFULL
If it is determined that the value obtained by subtracting the pre-cylinder correction final injection amount command value QFINA from EGR is equal to or less than the EGR determination command value QEGR (S435: NO), the process proceeds to S455.

In step S440, the transient intake pressure correction term MQF
It is determined whether or not the PT is being calculated, that is, whether or not the maximum injection amount command value QFULL is being reduced. Then, the transient intake pressure correction term MQFP
If it is determined that T is not being calculated (S4
40: NO), the step moves to S445, and when it is determined that the transient intake pressure correction term MQFPT is being calculated (S440: YES, the step is S455).
Move to

In S445, the basic EGR duty DE
BSE, EGR water temperature correction term NETHW, and intake pressure V
By multiplying by PIM, the final EGR duty DE
Calculate FIN. Then, in S450, an EGR drive signal based on the final EGR duty DEFIN is output to the EGR valve 30, and the program ends.

As described above in detail based on each embodiment, the control system DC for the diesel engine according to each of the above embodiments is described.
1, DC2 and DC3 are frequent EGR valves 3 respectively.
In order to suppress the opening / closing operation of 0, a first injection amount calculation program, a second injection amount calculation program, and an exhaust gas recirculation program are provided as components.

Accordingly, frequent opening and closing operations of the EGR valve 30 are suppressed, and the reliability and durability of the EGR valve 30 can be improved. Further, the maximum injection amount command value QFULL does not greatly change due to the opening / closing operation of the EGR valve 30, and the opening of the EGR valve 30 in the maximum injection amount command value QFULL region, that is, the exhaust gas recirculation can be prevented. The amount of generated diesel smoke can be suppressed.

The above effects will be described in detail with reference to the timing chart shown in FIG. FIG. 4 shows how the basic injection amount command value QBASE, the maximum injection amount command value QFULL, the final injection amount command value QFIN, and the accelerator opening ACCP, the engine speed NE, and the EGR final duty DEFIN change during acceleration. It is a timing chart shown.

During a period in which the basic injection amount command value QBASE is smaller than the maximum injection amount command value QFULL, the final injection amount command value QFIN adopts the basic injection amount command value QBASE. It is calculated based on the basic injection amount command value QBASE. Further, since the basic injection amount command value QBASE during acceleration uses the acceleration smoothing injection amount command value QSMA, the basic injection amount command value QBASE
The smoothing process is performed on E itself, and eventually exceeds the maximum injection amount command value QFULL.

Then, the final injection amount command value QFIN takes the maximum injection amount command value QFULL.
The value becomes equal to or less than the R determination command value QEGR, and the EGR valve 30 is closed. When the EGR valve 30 is closed, a decrease correction is performed on the maximum injection amount command value QFULL, and the maximum injection amount is reduced.

Here, conventionally, the acceleration smoothed injection amount command value QSMA is calculated based on the maximum injection amount command value QFULL, and as the maximum injection amount command value QFULL becomes smaller, the basic injection amount command value QSMA becomes smaller. The value QBASE was also reduced. Therefore, when the maximum injection amount command value QFULL increases due to the change of the decrease correction, the maximum injection amount command value QFULL becomes larger than the basic injection amount command value QBASE again, and the final injection amount command value QFIN becomes the basic injection amount command value QBASE. Take. As a result, the final injection amount command value QFI
The difference between N and the maximum injection amount command value QFULL becomes larger than the EGR determination command value QEGR, and the EGR valve 30 is opened.

At this time, the acceleration smoothing injection amount command value QSM
A is calculated based on the basic injection amount command value QBASE, and the basic injection amount command value QBASE immediately becomes larger than the maximum injection amount command value QFULL. Therefore, the final injection amount command value QFIN is equal to the maximum injection amount command value QFULL.
When the difference between the final injection amount command value QFIN and the maximum injection amount command value QFULL becomes equal to or less than the EGR determination command value QEGR, the EGR valve 30 is opened, and the reduction correction for the maximum injection amount command value QFULL is performed. Be executed. Here, since the EGR valve 30 (VSV31) has a response delay with respect to the EGR final duty DEFIN, in the region where the maximum injection amount command value QFULL is adopted as the final injection amount command value QFIN, And the amount of diesel smoke generated increased.

However, in the first injection amount calculation program in the first embodiment, the acceleration smoothing injection amount command value QS
MA is always calculated by performing an acceleration smoothing process on the basic injection amount command value QBASE, and the basic injection amount command value QBASE during acceleration is always calculated based on the basic injection amount command value on which the acceleration smoothing process is performed. A value QBASE (accelerated smooth injection amount command value QSMA) is taken. As a result, even when the maximum injection amount command value QFULL increases due to the change of the reduction correction, the basic injection amount command value QBASE does not become smaller than the maximum injection amount command value QFULL, and is once closed. The EGR valve 30 will not be opened again.

Accordingly, the EGR valve 30 is not frequently opened and closed, and the reliability and durability of the EGR valve 30 can be improved. Further, in a region where the final injection amount command value QFIN adopts the maximum injection amount command value QFULL, the EGR valve 30 is not opened, and the amount of diesel smoke generated can be suppressed. Further, since the EGR valve 30 is not frequently opened and closed, it is possible to prevent output torque fluctuation due to variation in the internal EGR amount.

In the second injection amount calculation program according to the second embodiment, when the basic injection amount command value QBASE is larger than the maximum injection amount command value QFULL, the governor pattern injection amount command is set as the basic injection amount command value QBASE. The value QGOV is adopted, and the acceleration smoothing injection amount command value QSMA is not adopted. That is, the last pre-cylinder correction final injection amount QF
The acceleration smoothing process for INAOL (previous final injection amount command value QFIN) is prohibited.

Therefore, basic injection amount command value QBASE
Becomes larger than the maximum injection amount command value QFULL, and the difference between the final injection amount command value QFIN and the maximum injection amount command value QFULL becomes equal to or less than the EGR determination command value QEGR.
The EGR valve 30 is opened, and the maximum injection amount command value QFUL
Even when the reduction correction is performed on L, the basic injection amount command value QBASE is not reduced due to the effect of reducing the maximum injection amount command value QFULL.

That is, the basic injection amount command value QBASE
Does not employ the acceleration smoothing injection amount command value QSMA, but employs the governor pattern injection amount command value QGOV. Therefore, the basic injection amount command value QBASE becomes the maximum injection amount command value QFUL.
This is because the parameter related to L is not included.

As a result, the magnitude relationship between the two does not reverse after the basic injection amount command value QBASE exceeds the maximum injection amount command value QFULL, and the frequent opening and closing operation of the EGR valve 30 is suppressed. 30 can be improved in reliability and durability. In a region where the final injection amount command value QFIN uses the maximum injection amount command value QFULL, the amount of diesel smoke generation can be suppressed without opening the EGR valve 30. Further, since the EGR valve 30 is not frequently opened and closed, it is possible to prevent output torque fluctuation due to variation in the internal EGR amount.

Further, in the exhaust gas recirculation prohibition processing program in the third embodiment, the difference between the final injection amount command value QFIN and the maximum injection amount command value QFULL becomes equal to or less than the EGR determination command value QEGR, or During the decrease correction for the amount command value QFULL (during calculation of the transient intake pressure correction coefficient MQFPT), the opening operation of the EGR valve 30 is prohibited (EGR final duty DEFIN = 0).

Here, conventionally, when the EGR valve 30 is closed and the maximum injection amount is being reduced,
The opening operation of the EGR valve 30 has been prohibited (EGR final duty DEFIN = 0). Therefore, when the maximum injection amount command value QFULL increases due to the change of the reduction correction, the difference between the final injection amount command value QFIN and the maximum injection amount command value QFULL is equal to or less than the EGR determination command value QEGR (E
Even if the condition for closing the GR valve 30 is satisfied), the condition for prohibiting the opening operation of the EGR valve 30 is removed, and the EGR valve 30 is closed.
Was open.

However, in the third embodiment, the opening operation of the EGR valve 30 is prohibited if the EGR valve 30 is closed or the maximum injection amount is being reduced. Therefore, even when the maximum injection amount command value QFULL increases due to the change of the decrease correction, the final injection amount command value QFIN and the maximum injection amount command value QFULL are increased.
Is smaller than or equal to the EGR determination command value QEGR (while the EGR valve 30 closing condition is satisfied), the EGR valve 30 is not opened.

As a result, the EGR valve 30 does not frequently open and close, and the reliability and durability of the EGR valve 30 can be improved. The difference between the final injection amount command value QFIN and the maximum injection amount command value QFULL is EGR.
When the value is equal to or less than the determination command value QEGR (while the EGR valve 30 is closed), the EGR valve 30 is not opened, so that the final injection amount command value QFIN uses the maximum injection amount command value QFULL. In this case, the EGR valve 30 is not opened, and the amount of diesel smoke generated can be suppressed. Further, the EGR valve 3
0 is not frequently opened and closed, so the internal E
It is possible to prevent output torque fluctuation due to variation in GR amount.

The present invention can be variously modified and improved without departing from the gist thereof. For example, in each of the above embodiments, the indirect injection diesel engine 10 that injects fuel into the sub-combustion chamber 18 has been described. However, the direct injection diesel engine that directly injects fuel into the combustion chamber (main combustion chamber 15) is described. May be applied. That is, a diesel engine provided with EGR has the above-described problems, and the effects of executing the above embodiments can be obtained.

In each of the above embodiments, the fuel injection pump 40 is provided separately from the diesel engine 10. However, like the fuel injection nozzle 20 provided in the cylinder head 12 of the diesel engine 10, A unit type fuel injection pump (unit injector) provided on the cylinder head 12 may be provided.

Further, in each of the above embodiments, each correction term and the like are calculated based on the map stored in the ROM 71. However, each correction term and the like may be calculated by directly substituting each parameter into a function. Good. In such a case, more accurate correction terms and the like can be calculated.

Further, the governor pattern injection amount command value QGO
V is calculated based on the accelerator opening ACCP and the engine speed NE, and the maximum injection amount command value QFULL is calculated based on the intake pressure VP.
Although the calculation is performed based on the IM or the like, the calculation may be performed based on another detection value. This is because the method of calculating these command values is merely an example.

The technical ideas other than the claims which can be understood from the above embodiments will be described below together with their effects. (1) In the control device for a diesel engine according to any one of claims 1 to 3, the exhaust gas recirculation means includes an exhaust gas recirculation device that connects an exhaust side and an intake side of the combustion chamber. A control device for a diesel engine, comprising: a circulation passage; and a control valve disposed in the middle of the exhaust gas recirculation passage and opening and closing the exhaust gas recirculation passage.

In the case where such a configuration is provided, the recirculation of the exhaust gas to the combustion chamber is executed or stopped by the control valve opening and closing the exhaust gas recirculation passage.

[0119]

As described above, according to the control apparatus for a diesel engine according to the first aspect of the present invention, when the diesel engine is in an accelerating state, the basic value required for the previously calculated fuel injection pump is calculated. An acceleration smoothing injection amount calculating means for calculating an acceleration smoothing injection amount based on the injection amount is provided.

Therefore, the basic injection amount is not affected by a change in the maximum injection amount, which is reduced for a predetermined period, and once the basic injection amount exceeds the maximum injection amount, the maximum injection amount is again reduced to the basic injection amount. Never exceed. As a result, frequent operation / stop of the exhaust gas recirculation means can be prevented, and output torque fluctuation can be suppressed.
Further, the operation of the exhaust gas recirculation means under the condition that the final injection amount adopts the maximum injection amount is prevented, and the amount of diesel smoke generated can be suppressed.

According to the control apparatus for a diesel engine according to the second aspect of the present invention, when accelerating and the basic injection amount is larger than the maximum injection amount, only the governor pattern injection amount is used. A basic injection amount calculating means for calculating a basic injection amount is provided.

Therefore, during acceleration, the maximum injection amount is not used as a parameter for calculating the basic injection amount, and the basic injection amount is not affected by the fluctuation of the maximum injection amount. After exceeding the maximum injection amount, the maximum injection amount does not exceed the basic injection amount again. As a result, frequent operation / stop of the exhaust gas recirculation means can be prevented, and output torque fluctuation can be suppressed. Further, the operation of the exhaust gas recirculation means under the condition that the final injection amount adopts the maximum injection amount is prevented, and the amount of diesel smoke generated can be suppressed.

Further, according to the control apparatus for a diesel engine according to the third aspect of the present invention, when the diesel engine is not in the exhaust gas recirculation area or when the maximum injection amount is reduced, the exhaust gas recirculation is performed. Exhaust gas recirculation inhibiting means for inhibiting exhaust gas recirculation by the means.

Therefore, the end of the weight reduction period regardless of whether the diesel engine is in the exhaust gas recirculation area or not, the exhaust gas recirculation means enables the exhaust gas recirculation means despite the fact that the diesel engine is in the non-exhaust gas recirculation area. No recirculation is performed. As a result, frequent operation / stop of the exhaust gas recirculation means can be prevented, and output torque fluctuation can be suppressed. Further, the operation of the exhaust gas recirculation means under the condition that the final injection amount adopts the maximum injection amount is prevented, and the amount of diesel smoke generated can be suppressed.

[Brief description of the drawings]

FIG. 1 is a conceptual configuration diagram showing a basic conceptual configuration of a diesel engine control device according to the present invention.

FIG. 2 is a system configuration diagram showing a schematic configuration of a diesel engine system to which the present invention is applied.

FIG. 3 is a control block diagram in a control device of the diesel engine.

FIG. 4 shows a basic injection amount command value QBAS during acceleration.
E, maximum injection amount command value QFULL, final injection amount command value Q
FIN, accelerator opening ACCP, engine speed N
E, A timing chart showing how the EGR final duty DEFIN changes.

FIG. 5 is a flowchart showing a first injection amount calculation program as a main routine in the first embodiment.

FIG. 6 is a flowchart showing a maximum injection amount calculation program as a subroutine.

FIG. 7 is a flowchart showing a previous last injection amount command value storage program as an interrupt routine.

FIG. 8 is a flowchart showing a second injection amount calculation program as a main routine in a second embodiment.

FIG. 9 is a flowchart showing an exhaust gas recirculation prohibition processing program as a main routine in a third embodiment.

FIG. 10 shows changes in a basic injection amount command value QBASE, a maximum injection amount command value QFULL, a final injection amount command value QFIN, an accelerator opening ACCP, an engine speed NE, and an EGR final duty DEFIN during acceleration according to a conventional example. The timing chart which shows a situation.

[Explanation of symbols]

10: diesel engine, 30: EGR valve, 31
VSV, 40 fuel injection pump, 81 water temperature sensor,
83 ... intake pressure sensor, 84 ... accelerator opening degree sensor, 8
6 ... Rotation speed sensor, DC1, DC2, DC3 ... Diesel engine control device, 70 ... ECU, 71 ... ROM, 73
… RAM, M1… Diesel engine, M2… Combustion chamber, M3
... Fuel injection pump, M4 ... Operation state detection means, M5 ... Governor pattern injection amount calculation means, M6 ... Engine acceleration state judgment means, M7 ... Acceleration smooth injection amount calculation means, M8 ... Basic injection amount calculation means, M9 ... Maximum Injection amount calculation means, M10: Final injection amount calculation means, M11: Exhaust gas recirculation area calculation means, M12: Exhaust gas recirculation means, M13: Engine transient state determination means, M14: Maximum injection amount correction means, M15: Acceleration smoothing Injection amount calculation means, M16 ... basic injection amount calculation means,
M17: Means for inhibiting exhaust gas recirculation.

Continuation of the front page (56) References JP-A-2-305336 (JP, A) JP-A-6-336938 (JP, A) JP-A-5-71385 (JP, A) JP-A-6-159154 (JP) , A) JP-A-7-158483 (JP, A) JP-A 63-113737 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) F02D 41/02 380 F02D 41/10 380 F02D 43/00 301 F02M 25/07 570

Claims (3)

(57) [Claims] 1. A fuel injection pump for supplying fuel to a combustion chamber of a diesel engine, an operating state detecting means for detecting an operating state of the diesel engine, and an engine rotation detected by the operating state detecting means Number, governor pattern injection amount calculation means for calculating the governor pattern injection amount based on the accelerator opening, etc., and whether or not the diesel engine is in an accelerated state based on the operation state detected by the operation state detection means. Engine acceleration state determination means for determining, and when the engine acceleration state determination means determines that the diesel engine is in an accelerated state, the previously calculated basic injection amount required for the fuel injection pump is calculated. An acceleration smoothing injection amount calculating unit for calculating an acceleration smoothing injection amount based on the engine acceleration state determining unit; When it is determined that the engine is in an accelerated state, a basic injection amount calculation unit for calculating a basic injection amount based on the smaller injection amount of the governor pattern injection amount or the acceleration smoothing injection amount, A maximum injection amount calculation unit for calculating a maximum injection amount based on the intake pressure detected by the operation state detection unit, and the fuel injection based on the smaller injection amount of the basic injection amount or the maximum injection amount A final injection amount calculating unit for calculating a final injection amount to be finally supplied to the combustion chamber by a pump; and a difference between the maximum injection amount and the final injection amount is detected by the operating state detecting unit. If the amount is larger than the exhaust gas recirculation determination amount calculated based on the operating state, the exhaust gas recirculation area is determined to be in the exhaust gas recirculation area. And means, when the diesel engine is determined to be in the exhaust gas recirculation area by the exhaust gas recirculation area determining means,
Exhaust gas recirculation means for recirculating a part of the exhaust gas discharged from the combustion chamber to the combustion chamber, and the diesel engine is moved from the exhaust gas recirculation area based on the result determined by the exhaust gas recirculation area determination means. An engine transient state determining means for determining whether or not the engine is in a transition state to a non-exhaust gas recirculation area; and a transition of the diesel engine from the exhaust gas recirculation area to the non-exhaust gas recirculation area by the engine transient state determining means. A control device for a diesel engine, comprising: a maximum injection amount correction means for reducing the maximum injection amount for a predetermined period when it is determined that the state is in a state. 2. A fuel injection pump for supplying fuel to a combustion chamber of a diesel engine, an operating state detecting means for detecting an operating state of the diesel engine, and an engine rotation detected by the operating state detecting means. Number, governor pattern injection amount calculation means for calculating the governor pattern injection amount based on the accelerator opening, etc., and whether or not the diesel engine is in an accelerated state based on the operation state detected by the operation state detection means. Engine acceleration state determination means for determining, and when the engine acceleration state determination means determines that the diesel engine is in an accelerated state, the fuel injection pump calculated last time finally enters the combustion chamber. Acceleration smoothing injection amount calculating means for calculating an acceleration smoothing injection amount based on a final injection amount to be supplied, and the engine acceleration state When it is determined by the disconnection means that the diesel engine is in an accelerated state, and when the basic injection amount is greater than the maximum injection amount, the basic injection amount is determined based only on the governor pattern injection amount. A basic injection amount calculating means for calculating, a maximum injection amount calculating means for calculating a maximum injection amount based on the intake pressure detected by the operating state detecting means, and the like, the basic injection amount or the maximum injection amount. A final injection amount calculating means for calculating a final injection amount to be finally supplied to the combustion chamber by the fuel injection pump based on any of the smaller injection amounts; and a calculation of the maximum injection amount and the final injection amount. If the difference is larger than the exhaust gas recirculation determination amount calculated based on the operating state detected by the operating state detecting means, the diesel engine may control the exhaust gas recirculation. An exhaust gas recirculation region determination means determines that the region, when the diesel engine is determined to be in the exhaust gas recirculation area by the exhaust gas recirculation area determining means,
Exhaust gas recirculation means for recirculating a part of the exhaust gas discharged from the combustion chamber to the combustion chamber, and the diesel engine is moved from the exhaust gas recirculation area based on the result determined by the exhaust gas recirculation area determination means. An engine transient state determining means for determining whether or not the engine is in a transition state to a non-exhaust gas recirculation area; and a transition of the diesel engine from the exhaust gas recirculation area to the non-exhaust gas recirculation area by the engine transient state determining means. A control device for a diesel engine, comprising: a maximum injection amount correction means for reducing the maximum injection amount for a predetermined period when it is determined that the state is in a state. A fuel injection pump for supplying fuel to a combustion chamber of the diesel engine; an operating state detecting means for detecting an operating state of the diesel engine; and an engine rotation detected by the operating state detecting means. Number, governor pattern injection amount calculation means for calculating the governor pattern injection amount based on the accelerator opening, etc., and whether or not the diesel engine is in an accelerated state based on the operation state detected by the operation state detection means. Engine acceleration state determination means for determining, and when the engine acceleration state determination means determines that the diesel engine is in an accelerated state, the fuel injection pump calculated last time finally enters the combustion chamber. Acceleration smoothing injection amount calculating means for calculating an acceleration smoothing injection amount based on a final injection amount to be supplied, and the engine acceleration state If it is determined by the disconnection means that the diesel engine is in an accelerated state, a basic injection for calculating a basic injection amount based on the smaller injection amount of the governor pattern injection amount or the accelerated smoothing injection amount. An amount calculating means, a maximum injection amount calculating means for calculating a maximum injection amount based on the intake pressure detected by the operating state detecting means, etc., and an injection amount which is smaller of the basic injection amount or the maximum injection amount. A final injection amount calculating means for calculating a final injection amount to be finally supplied to the combustion chamber by the fuel injection pump based on the difference between the maximum injection amount and the final injection amount. If the amount is larger than the exhaust gas recirculation determination amount calculated based on the operation state detected by the detection means, the diesel engine is in the exhaust gas recirculation region. An exhaust gas recirculation region determining means for determining, when the diesel engine is determined to be in the exhaust gas recirculation area by the exhaust gas recirculation area determining means,
Exhaust gas recirculation means for recirculating a part of the exhaust gas discharged from the combustion chamber to the combustion chamber, and the diesel engine is moved from the exhaust gas recirculation area based on the result determined by the exhaust gas recirculation area determination means. An engine transient state determining means for determining whether or not the engine is in a transition state to a non-exhaust gas recirculation area; and a transition of the diesel engine from the exhaust gas recirculation area to the non-exhaust gas recirculation area by the engine transient state determining means. If it is determined that the diesel engine is in the state, the maximum injection amount is reduced by a maximum injection amount for a predetermined period, and the exhaust gas recirculation region determination unit determines that the diesel engine is not in the exhaust gas recirculation region. Or when the maximum injection amount is reduced by the maximum injection amount correction means, the exhaust gas is recirculated by the exhaust gas recirculation means. Control device for a diesel engine, characterized in that a flue gas recirculation inhibiting means for inhibiting the ring.