JPS6019943A - Method of moderately controlling fuel injection quantity in diesel engine - Google Patents

Abstract

PURPOSE:To effectually reduce the shock of acceleration and deceleration in a wide range of operation and prevent white smoke from being made, by gradually nearing the quantity of injected fuel or the degree of opening of an accelerator to an aimed value by every allowable alteration quantity in the acceleration or deceleration. CONSTITUTION:It is detected by sensors whether the temperature of cooling water of engine, the speed of a vehicle, the shifted position of a manual transmission and the revolution speed of the engine are higher or lower than prescribed values. The maximum of allowable increases alpha1, alpha2, alpha3, alpha4, which are determined when said quantities are lower than the prescribed values, and the maximum of allowable decreases beta1, beta2, beta3, beta4, which are determined when said quantities are higher than the prescribed values, are used as a final allowable increase alpha and a final allowable decrease beta. An aimed value Qi for the quantity of injected fuel is calculated depending on the revolution speed of the engine and the degree of opening of the accelerator. In the acceleration of the engine, the quantity of injected fuel is gradually augmented to the aimed value Qi by every allowable increase alpha. In the deceleration of the engine, the quantity of inected fuel is gradually reduced to the aimed value Qi by every allowable decreases beta. The quantity of injected fuel is thus moderately controlled. This results in reducing the shock of the acceleration and deceleration and preventing white smoke from being made by the engine furnished with an intake orifice.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a fuel injection edge smoothing control method for a diesel engine, and particularly to a method for controlling engine rotational speed and edge smoothing, which is suitable for use in an electronically controlled diesel engine for automobiles equipped with a manual transmission. When determining the fuel injection amount according to the engine operating condition including the accelerator opening, the fuel injection amount is determined during acceleration and deceleration.
The present invention also relates to an improvement in a fuel injection amount smoothing control method for a diesel engine that reduces acceleration/deceleration by smoothing the accelerator opening.

Generally, in a diesel engine, cylinder surface pressure is high due to high compression, and mechanical loss due to friction and the like is large. Therefore, when decelerating by fully opening the accelerator pedal,
Compared to the Ganlin engine, engine braking is stronger, and in particular, in diesel engines that have a function to cut fuel when the accelerator pedal is fully opened at a predetermined engine speed or higher, the negative torque caused by engine braking is Because of the large size, the traveling speed of the automobile would be rapidly reduced, and there was a risk that the deceleration would be so large that it would make the occupants feel uncomfortable.

In order to solve these problems, for example,
-28829, by limiting the rate of decrease in fuel injection amount to below a predetermined limit value during sudden deceleration,
It has been proposed to perform so-called smoothing processing to reduce the deceleration shock, especially during engine braking.

However, engine rotation speed, vehicle running speed,
There are variations in deceleration shock depending on the shift position of a manual transmission, and it has been difficult to effectively prevent deceleration shock in all driving ranges.

Also, if you perform the so-called guard process, which stops the fuel at a certain 111% ω during smoothing or deceleration, and then slowly decreases the fuel injection amount from there, it will be especially difficult for diesel engines equipped with an intake throttle to control the amount of intake air. The present invention was made in order to solve the above-mentioned conventional problems in which white smoke was sometimes generated in engines, and it is possible to effectively reduce acceleration/deceleration shocks in a wide operating range. However, the purpose of this invention is to provide a fuel injection amount smoothing control method for a diesel engine that can prevent the generation of white smoke.

The present invention provides the following advantages when determining the fuel injection amount according to engine operating conditions including engine speed and accelerator opening.
Diesel engine fuel 11j [Ql] in which the acceleration/deceleration is reduced by smoothing the fuel injection gA amount or accelerator opening during acceleration/deceleration. A procedure for determining the permissible amount of change in fuel injection amount or accelerator opening according to at least one of the following: a change in the gear position of a transmission, an engine rotational speed, and an accelerator opening; A procedure for determining the target value of the fuel injection amount or accelerator opening from etc., a procedure for determining whether acceleration or deceleration is being performed, and a procedure for determining the fuel injection amount or accelerator opening from the above-mentioned allowable value. The above objective is achieved by including a procedure of gradually approaching the target value by the amount of change.

Further, in an embodiment of the present invention, the permissible change i in the fuel injection amount or accelerator opening degree is determined by a permissible change amount according to the engine cooling water temperature, an allowable change amount according to the traveling speed of the vehicle, and a shift position of the transmission. The maximum value of the permissible change according to the engine rotational speed is set so that an appropriate permissible change can be selected even when the permissible change is determined from a large number of parameters. It is something.

Furthermore, in another embodiment of the present invention, when the engine cooling water temperature is low, the allowable change amount is increased,
This is to prevent the generation of white smoke from increasing.

Further, in another practical IM aspect of the present invention, when the traveling speed of the vehicle is high, the permissible change amount is increased to prevent deterioration of the vehicle driving performance during acceleration, and to prevent deterioration of the vehicle driving performance during deceleration. This prevents the generation of white smoke and improves the effectiveness of engine braking.

Furthermore, in another embodiment of the present invention, when the shift position of the transmission is on the low speed side, the allowable change amount is set small to alleviate acceleration/deceleration shock. .

Furthermore, in another embodiment of the present invention, during sudden acceleration when the amount of change in the accelerator opening is large in the positive direction, the allowable amount of change is made large; on the other hand, when the amount of change in the accelerator opening is negative When there is a sudden deceleration in the direction of the vehicle, the permissible amount of change is reduced to improve the acceleration performance and the effectiveness of the engine brake.

In the present invention, when performing smoothing processing on the fuel injection amount or accelerator opening, the allowable change amount is defined as changes in engine cooling water temperature, vehicle running speed, transmission shift position, engine rotation speed, and accelerator opening. Since the amount is changed according to at least one of the amounts, acceleration/deceleration shock can be effectively prevented over a wide driving range, and the generation of white smoke can also be prevented.

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an electronically controlled automobile diesel engine equipped with a manual transmission, in which the fuel injection amount smoothing control method for a diesel engine according to the present invention is adopted, will be described in detail below with reference to the drawings.

In this embodiment, as shown in FIG. 2, a diesel engine 1
A drive shaft 14 that rotates in conjunction with the rotation of the output shaft of 0, and a noid pump 1'6 fixed to the drive shaft 14 for pumping fuel (Figure i2 shows a state rotated by 90 degrees).
From the fuel pressure adjustment valve 18 for adjusting the fuel supply pressure, and the simultaneous rotational displacement of the gear 20 fixed to the drive shaft 14, the time required for the hetodynamic pongee 14 to rotate by a predetermined crank angle is measured. The rotation speed sensor 22, which is composed of an electromagnetic pickup, for example, is used to detect the rotation speed of the diesel engine 1o, and detects the fuel injection timing &! A roller ring 24 for controlling the roller ring 24, a timer piston 26 for driving the roller ring 24, a timing control valve 28 for controlling the position of the timer piston 26, and a mechanism for detecting the position of the timer piston 26. , a timer position sensor 30 consisting of, for example, a variable inductance sensor, a spill ring 32 for controlling the fuel injection amount, and the spill ring 3
Plunger 34a and compression spring 34 for driving 2.
b1 A spill actuator 34 consisting of a coil 34c and a coil case 34 (1), a spill position sensor 36 consisting of, for example, a variable inductance sensor for detecting the position of the spill ring 32 from the displacement of the plunger 34, and a spill position sensor 36 for cutting fuel when the engine is stopped. The fuel UJA includes a fuel cut solenoid (hereinafter referred to as FCV) 38, a plunge 1740, and a delivery pulp 42.
an injection nozzle 4 for injecting fuel discharged from the delivery valve 42 of the fuel injection pump 12 into the sub-combustion chamber of the diesel engine 10.
4, an intake pressure sensor 48 for detecting the pressure of intake air taken in through the intake pipe 46, an intake temperature sensor 50 for similarly detecting the mW of the intake air, and a cylinder block 10a of the diesel engine 10. placed in
a water wetness sensor 52 for detecting engine cooling water temperature;
An accelerator sensor 54 for detecting the depression angle of an accelerator pedal 53 operated by the driver (hereinafter referred to as accelerator opening); a manual transmission 55 for changing the gear ratio according to the driving condition of the automobile; A vehicle speed sensor 56 for detecting the traveling speed of the automobile, that is, the vehicle speed from the rotational speed of the output shaft of the manual transmission 55, and the shift position of the manual transmission 55.

That is, a shift position switch 5 for detecting the shift position.
The target 11R error timing and An electronic control unit that controls the timing control valve 28, the spill actuator 34, etc. so that the calculated amount of fuel is injected from the fuel injection pump 12 at the target injection timing q. (hereinafter referred to as ECU)
) 58.

In the figure, 25 is a cam plate, and 33 is a tension spring.

As shown in detail in FIG. 3, the ECU 38 includes a central processing unit (hereinafter referred to as "CPU") 59 made of, for example, a microcomputer for performing various arithmetic processes;
The cooling water temperature sensor 5 input via the buffer 60
2 outputs, the output of the intake air temperature sensor 50 which is input via a buffer 62, the output of the intake pressure sensor 48 which is input via a buffer 64, the output of the accelerator sensor 54 which is input via a buffer 66, and the buffer 67. The vehicle speed sensor 56 output is inputted via the sensor drive circuit 68
The output of the spill position sensor 36 is driven by an output frequency signal for driving the sensor and input via the sensor signal detection circuit 70, and the output of the spill position sensor 36 is driven by the frequency signal for driving the sensor output from the sensor drive circuit 72, and the sensor signal is detected. The timer position sensor 3 input via the circuit 74
A multiplexer 76 for sequentially taking in outputs, etc., and an analog-to-digital converter (hereinafter referred to as A) for converting the analog signal output from the multiplexer 76 into a digital signal.
/D converter) 78, an input/output port 80 for inputting the output of the A/D converter 78 to the CPU 59, and the shift position switch 5 inputted via the buffer 82.
7 output, a waveform shaping circuit 94 for waveform shaping the output of the city record rotation speed 1 good sensor 22 and inputting it into the CPU 59, and a clock generation circuit 10.
2, and a backup random access memory (hereinafter referred to as backup R) that is used to temporarily store calculation data etc. in the CPL 159 and is backed up in the event of a power failure.
A random access memory (hereinafter referred to as RAM) 104 including a RAM (hereinafter referred to as RAM), and a read-only memory (hereinafter referred to as ROM) 106 for storing control programs, various data, etc. A drive circuit 108 for driving the timing control valve 28 in accordance with the calculation result in the CPLI 59, a drive circuit 109 for driving the FCV 38 in accordance with the calculation result in the CPU 59, and a digital-to-analog converter ( A servo amplifier 112 for driving the spill actuator 34 according to the deviation between the output of the CPU 59 and the output of the spill position sensor 36, which is converted into an analog signal by a D/A converter (hereinafter referred to as a D/A converter) 110. and a drive circuit 114.

The action will be explained below.

Calculation of the fuel injection amount in this embodiment is performed according to the flowchart shown in Figure 4. That is, first step 1
At step 10, it is determined whether the engine cooling water temperature determined from the output of the water temperature sensor 52 is less than a predetermined value, for example, 60°C. When the determination result is positive, that is, when it is determined that the engine coolant temperature is low, the process proceeds to step 112, and the allowable increase amount α1 and allowable decrease amount β1 according to the engine coolant temperature are set to relatively large values, e.g. 0.5
．． Enter 6.3. On the other hand, if the determination result in step 110 is negative, the process proceeds to step 114, where the allowable increase amount α1 and allowable decrease amount β1 according to the engine cooling water temperature are set to relatively small values, for example, 0.20.0. .1
Enter 3.

After completing step 112 or 114, Stella 7116
Then, it is determined whether the vehicle speed determined from the output of the vehicle speed sensor 56 is less than a predetermined value, for example, 40 km/l+. If the determination result is positive, the process proceeds to step 118, where the allowable increase amount α2 and allowable decrease amount β2 according to the vehicle speed are set to relatively small values, for example, 0.24.0.
Enter 16. On the other hand, if the determination result in step 116 is negative, that is, if it is determined that the vehicle speed is high, the process proceeds to step 120, and relatively Enter a large value, for example 0.30.0.25.

After completing step 118 or 120, step 122
, and according to the output of the shift position switch 57,
It is determined whether or not the manual transmission 55 is in the first speed. If the determination result is positive, that is, if it is determined that the shift position is the first gear on the low speed side, step 12
4, the allowable increase tooth α3 and allowable decrease amount β3 according to the shift position are set to relatively small values, for example, 0.
24, enter 0.16. On the other hand, if the determination result in step 122 is negative, the process proceeds to step 126, where the allowable increase amount α3 and allowable decrease amount β3 according to the shift position are set to relatively large values, for example, 0.32.0. .2
Enter 7.

After completing step 124 or 126, step 128
Then, the engine rotation speed NE is set to a predetermined value, for example, 250 Orpm, according to the output of the rotation speed sensor '22.
Determine whether or not it exceeds.

If the determination result is positive, that is, if it is determined that the engine rotational speed is high, the process proceeds to step 130, and relatively large values are set as the allowable increase amount α4 and allowable decrease amount β4 according to the engine rotational speed. For example 0.27.0
．． Enter 20. On the other hand, if the determination result in step 128 is negative, the process proceeds to step 132, where the allowable increase amount α4 and allowable decrease amount β4 according to the engine speed are set to relatively small values, for example, 0.24. .0.1
Enter 6.

After the above step 130 or 132 is completed, step 13
Proceed to step 4, and calculate each allowable increase amount α1, α as shown in the following formula.
2, α3, α4, and the maximum values of the allowable decreases β1, β2, β3, and β4 are the final allowable increases α and allowable decreases β, respectively.

α<-MAX A target value Q1 of the fuel injection amount is calculated according to the engine rotational speed determined from the output of the rotational speed sensor 22, the accelerator opening degree determined from the output of the accelerator sensor 54, and the like. Next, the process proceeds to step 138, where it is determined whether or not the vehicle is accelerating, for example because the accelerator opening is increasing.

If the determination result is positive, proceed to step 140;
The fuel injection amount is smoothed by gradually increasing the fuel injection amount from the fuel injection amount immediately before the acceleration determination to the target value Qi by the allowable increase amount α determined in step 134 described above.

On the other hand, if the determination result in step 138 is negative, the process proceeds to step 142, where it is determined whether or not the vehicle is decelerating because, for example, the accelerator opening is decreasing. If the determination result is positive, the process proceeds to step 144, and the fuel injection amount is increased from the fuel injection amount 9Affl immediately before the deceleration determination to the target value Q1 determined in the aforementioned step 134.
The fuel injection amount is smoothed by gradually reducing it by the allowable reduction amount β.

On the other hand, if the determination result in step 142 is negative,
In other words, when it is determined that there is no need to perform smoothing processing during acceleration and deceleration, fuel injection is performed! ) is controlled so that it matches the target value Ql.

In this way, acceleration/deceleration shocks can be effectively suppressed over a wide driving range by changing the allowable changes α and β in the fuel injection amount according to engine cooling water temperature, vehicle speed, transmission position, engine rotational speed, etc. can be reduced to or,
Even in a diesel engine equipped with an intake throttle device, no white smoke is generated.

In this embodiment, each allowable increase amount α1, α2, α
3. α4, allowable reduction amount β4, β2, β3, β,
The control is simple because each of them takes two values, large and small. Note that it is also possible to determine the allowable increase amount and allowable decrease amount using a calculation formula as a function of engine cooling water temperature, etc.

In addition, in this example, the allowable change amount is determined by water temperature, vehicle speed,
Since the change is made according to the four parameters of the shift position and the engine speed, and the final allowable change amount is the maximum value, fine control is performed and the allowable change amount is easy to determine.

Note that the number of parameters, the legal method for determining the final allowable change amount, etc. are not limited to these.

In the above embodiment, during acceleration or deceleration, the smoothing process was performed using the allowable increase amount α and allowable decrease amount 8β of − elongation, respectively, but the values of the allowable increase amount α and allowable decrease amount β is changed according to the amount of change in the accelerator opening. For example, during sudden acceleration when the amount of change in the accelerator opening is large in the positive direction, the allowable increase amount α is set to be large, while the amount of change in the accelerator opening is During sudden deceleration when is large in the negative direction, it is also possible to set the allowable reduction amount β to a small value so that more appropriate smoothing processing can be performed during sudden acceleration and deceleration.

Further, in the above embodiment, the smoothing process during acceleration/deceleration was performed on the fuel injection amount, but the target to which the smoothing process is performed is not limited to this, and the smoothing process is performed on the accelerator opening degree. It is also possible to configure the system to perform the following.

In the above embodiments, the present invention was applied to an electronically controlled diesel engine for an automobile equipped with a manual transmission, but the scope of application of the present invention is not limited thereto, and is applicable to an automobile equipped with an automatic transmission. It is clear that the present invention can be similarly applied to electronically controlled diesel engines and general diesel engines.

As explained above, according to the present invention, acceleration/deceleration shocks can be effectively reduced over a wide driving range. Further, even in a diesel engine equipped with an intake throttle device, the generation of white smoke can be reduced. Therefore, it has the excellent effect of improving heavy vehicle operation performance and exhaust gas purification performance.

[Brief explanation of drawings]

FIG. 1 is a flowchart without showing the gist of the fuel injection amount smoothing control method for a diesel engine according to the present invention, and FIG. 2 is an electronically controlled automobile diesel engine equipped with a manual transmission to which the present invention is adopted. FIG. 3 is a cross-sectional view showing the configuration of an embodiment of the engine, including a partial block diagram; FIG. 3 is a block diagram showing the configuration of the electronic control unit used in the embodiment; FIG. , is a flowchart showing the main part of a routine for calculating the fuel injection amount. DESCRIPTION OF SYMBOLS 10... Diesel engine, 12... Fuel injection pump, 22... Rotational speed sensor, 52... Water temperature sensor, 54... Accelerator sensor, 55... Manual transmission, 56... Vehicle speed sensor,
57...Shift position switch, 58...Electronic control unit (ECtJ). Agent Takaya Ron (and 1 other person)

Claims (6)

[Claims] (1) When determining the fuel injection amount according to engine operating conditions including engine speed and accelerator opening, when accelerating or decelerating, smoothing processing is performed on the fuel injection amount or accelerator opening to reduce acceleration/deceleration. In the fuel injection amount smoothing control method for a diesel engine, the fuel injection amount is adjusted according to at least one of the following: engine cooling water temperature, vehicle traveling speed, transmission shift position, engine rotation speed, and amount of change in accelerator opening. Spout! 11m or accelerator opening, a procedure for calculating the target value of the fuel injection amount or accelerator opening from the engine rotation speed, accelerator opening, etc., and a procedure for determining whether acceleration or deceleration is in progress. and, during acceleration/deceleration, a step of gradually bringing the fuel injection amount or accelerator opening degree closer to the target value by the permissible change amount. Method. (2) The permissible amount of change in the fuel injection amount or accelerator opening is determined according to the engine cooling water temperature, the vehicle running speed, and the gear position of the transmission; 2. The fuel eruption annealing control method for a diesel engine according to claim 1, wherein the maximum value of the permissible change amount is determined according to the rotational speed of the engine. (3) The fuel injection amount smoothing control method for a diesel engine according to claim 1 or 2, wherein when the engine cooling water temperature is low, the allowable change amount is increased. (4) When the traveling speed of the vehicle is high, the permissible change amount is increased.
The fuel injection amount smoothing control method for a diesel engine described in . (5) If the shift position of the transmission is on the low speed side,
The fuel injection amount smoothing control method for a diesel engine according to claim 1 or 2, wherein the allowable change amount is made small. (6) During sudden acceleration when the amount of change in the accelerator opening is large in the positive direction, the allowable amount of change is set to be large; on the other hand, during sudden deceleration when the amount of change in the accelerator opening is large in the negative direction, the above-mentioned Acceptable! Claim 1 in which the amount of quantification is reduced
The fuel injection amount smoothing control method for a diesel engine described in .