JPS6032961A - Fuel injection moderating control method for diesel engine - Google Patents

Abstract

PURPOSE:To reduce acceleration/deceleration shock reliably and to achieve quick acceleration/deceleration by providing a step for deciding that it is under acceleration/deceleration and a step for bringing the fuel injection or the accelerator opening near to the target level. CONSTITUTION:Steps for deciding that it is under acceleration/deceleration, for detecting the elapsed time after start of acceleration/deceleration and for obtaining the allowable variation of accelerator opening or fuel injection in correspondense with the elapsed time are provided. Furthermore, a step for bringing the fuel injection quantity or the accelerator opening step by step near to the target level is provided. Since proper moderating processing can be performed in accordance with the acceleration/deceleration state, shock can be reduced reliably resulting in smooth acceleration/deceleration.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a fuel injection amount smoothing control method for a diesel engine, and particularly to a method for smoothing the engine rotation speed and the like, which is suitable for use in an electronically controlled diesel engine for automobiles equipped with a manual transmission. Fuel for a diesel engine in which the fuel injection amount or accelerator opening is smoothed during acceleration/deceleration to reduce acceleration/deceleration shock when determining the fuel injection amount according to engine operating conditions including the accelerator opening. This invention relates to improvements in injection quantity smoothing control methods.

Diesel engines, especially electronically controlled diesel engines for automobiles, use fuel injection equipment and the amount of change in accelerator opening during acceleration and deceleration to reduce acceleration shock during acceleration and deceleration shock during deceleration. So-called fuel injection amount smoothing control has been proposed, which performs smoothing processing based on the limit and alleviates acceleration/deceleration shock.

However, if the allowable change amount is constant regardless of the acceleration/deceleration state, for example, if the allowable change amount is made small in order to reduce acceleration shock, the acceleration feeling will be bad (on the other hand, the acceleration feeling may be improved). If the allowable amount of change is increased in order to increase the amount of change, there is a problem in that acceleration shock remains.This also applies to deceleration shock.

The present invention has been made in order to solve the above-mentioned conventional problems, and it is possible to perform appropriate fuel injection amount smoothing control according to the acceleration and M speed state, and therefore, it is possible to reliably reduce acceleration/deceleration shock. It is an object of the present invention to provide a method for annealing a fuel injection lid of a diesel engine, which allows for rapid acceleration and deceleration.

The present invention provides the following advantages when determining the fuel injection amount according to engine operating conditions including engine speed and accelerator opening.
A procedure for determining whether acceleration or deceleration is being performed in a fuel injection lid smoothing control method for a diesel engine in which the fuel injection amount or accelerator opening is smoothed during acceleration or deceleration to alleviate acceleration/deceleration shock. and when accelerating or decelerating,
A procedure for detecting the elapsed time after the start of acceleration/deceleration, a procedure for calculating the allowable amount of change in the fuel injection lid or accelerator opening according to the elapsed time after the start of acceleration/deceleration, and a procedure for determining the opening of the fuel injection lid or the accelerator. The above object is achieved by including the step of gradually approaching the target value by the permissible change amount.

Further, in an embodiment of the present invention, the allowable change amount is small at the beginning of acceleration/deceleration, so that smoothing processing that matches the acceleration/deceleration state can be easily performed.

In the present invention, the adjustment is 3! Since the allowable amount of change in fuel injection amount or accelerator opening is changed according to the elapsed time after the start, it is possible to perform appropriate smoothing processing according to the acceleration/deceleration state, and therefore reduce acceleration/deceleration shock. It is possible to reliably reduce the speed and then accelerate and decelerate immediately.

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an electronically controlled automobile diesel engine equipped with a manual transmission, in which a fuel injection lid 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 the engine; a feed pump 16 fixed to the drive shaft 14 for feeding fuel under pressure (FIG. 2 shows a state rotated by 90 degrees);
1 = fuel pressure adjustment valve 18 for adjusting the fuel supply pressure;
For detecting the rotation speed of the diesel engine 10 by measuring the time required for the drive shaft 14 to rotate by a predetermined crank angle from the rotational displacement of the gear 20 fixed to the drive shaft 14, For example, a rotational speed sensor 22 consisting of an electromagnetic pickup, a roller ring 24 for controlling fuel injection timing, a timer piston 26 for driving the roller ring 24, and a timing control for adjusting the position of the timer piston 26 A tine position sensor 30 consisting of a variable inductance sensor, for example, for detecting the position of the timer piston 26, a spill ring 32 for controlling the fuel injection amount, and a plunger for driving the spill ring 32. 34a1 compression spring 3
A spill actuator 34 consisting of a 4b1 coil 34c and a coil case 34d, a spill position sensor 36 consisting of, for example, a variable inductance sensor that detects the position of the spill ring 32 from the displacement of the plunger 34, and a spill position sensor 36 that cuts fuel when the engine is stopped. A fuel injection pump 12 having a fuel cut solenoid 38, a plunger 40, and a delivery valve 42, and the fuel discharged from the delivery valve 42 of the fuel injection pump 12 are injected into the sub-combustion chamber of the diesel engine 10. injection nozzle 44 and an intake pressure sensor 4 for detecting the pressure of intake air taken in through the intake pipe 46.
8, an intake temperature sensor 50 for similarly detecting the temperature of intake air, and a water temperature sensor 52 for detecting the engine cooling water temperature disposed in the cylinder block 10a of the diesel engine 10, which can be operated by the driver. An accelerator sensor 54 detects the depression angle of the accelerator pedal 53 (hereinafter referred to as accelerator opening), the accelerator opening detected from the output of the accelerator sensor 54, and the engine rotation detected from the output of the rotational speed sensor 22. The target injection timing and calculated injection amount are determined based on the speed, the engine cooling water temperature detected from the output of the cooling water depletion sensor 52, etc., and the fuel injection pump 12 injects the calculated amount of fuel at the target injection timing. It also includes an electronic control unit (hereinafter referred to as ECU) 58 that controls the timing control valve 28, spill actuator 34, etc.

In the figure J3, 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 humidity sensor 50 inputted via the buffer 62, the output of the intake pressure sensor 48 inputted via the buffer 64, the output of the accelerator sensor 54 inputted via the buffer 66, and sensor drive. The output of the spill position sensor 36 is driven by the sensor drive frequency signal output from the circuit 68 and is input via the sensor signal detection circuit 70, and the sensor drive frequency signal is also driven by the sensor drive frequency signal output from the sensor drive circuit 72 to detect the sensor signal. Tine position sensor 3 marked n1'J input via circuit 74
A multiplexer 76 for sequentially taking in the 0 output, 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 board 80 for inputting the output of the A/D converter 78 to the CPU 59, and a waveform shaping of the output of the rotational speed sensor 22 to be sent to the CPU 59.
A waveform shaping circuit 94, a clock generation circuit 102, and a backup random access memory (hereinafter referred to as a backup random access memory) for temporarily storing calculation data, etc. to be input to the CPU 59, and used as a backup in the event of a power failure. Random access memory (hereinafter referred to as RAM) 104 including a RAM (hereinafter referred to as RAM), and read-only memory (hereinafter referred to as RAM) for storing control programs, various data, etc.
(hereinafter referred to as ROM) 106, a drive circuit 108 for driving the timing control valve 28 according to the calculation result in the CPU 59, and a drive circuit 108 for driving the FCV 38 according to the calculation result in the CPU 59. 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 drive circuit 109 and a digital-to-analog converter (hereinafter referred to as a D/A converter) 110, the spill actuator It is composed of a servo amplifier 112 and a drive circuit 114 for driving the motor 34.

The action will be explained below.

Calculation of the fuel injection amount in this embodiment is executed according to a routine as shown in FIG. That is, first, in step 110, a target i value 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, etc.

Next, proceed to step 112 and use the current fuel of 11J! I
By comparing J fM with the previous fuel injection amount,
Determine whether the amount of fuel@copper is increasing. If the determination result is positive, that is, if it is determined that the vehicle is accelerating, the process proceeds to step 114, and the counter CM'l-, which counts the elapsed time after the start of acceleration, is set to 11. Next, the process proceeds to step 116, where it is determined whether or not the IC is such that the count value of the counter CM1- is equal to or greater than the set value corresponding to a set time, for example, 0.1 seconds.If the result of the determination is no, that is, When it is determined that the acceleration is in the initial stage, the process proceeds to step 118, and the permissible increase in the fuel q4θ1 range for performing the smoothing control IT is set to a relatively small set value a.

On the other hand, if the determination result in step 116 is positive,
That is, when it is determined that the acceleration is in the middle period or later, the process proceeds to step 120, and the fuel 11 for performing the smoothing control it is
Set the allowable increase in the amount of N swords to a relatively large setting value b (>a)
and J.

After completing step 118 or 120 above, step 122
The process proceeds to step 118 or step 1, where the previous fuel injection amount is
The smoothing process is performed by increasing the allowable increase Q11a or b set in step 20 once on the current m fuel injection side.

On the other hand, if the determination result in step 112 is negative,
That is, when it is determined that the time is not acceleration, the step f
Proceed to step 124 and click the counter CM1 with the click i7 L.
Prepare for the next acceleration start.

Fig. 5 shows an example of the elapsed time after the start of acceleration and the change state of the fuel injection amount in this embodiment. This is the actual fuel injection amount.

In this way, at the beginning of acceleration, the allowable increase in fuel injection amount is set small and the fuel increase is small, and after the middle of acceleration, the allowable increase is set large and the fuel increase is set relatively large, thereby reducing the acceleration shock at the beginning of acceleration. It is possible to reliably prevent this, ensure acceleration performance after the middle period of acceleration, and improve the °C1 acceleration feeling.

In this embodiment, depending on the elapsed time after the start of acceleration,
Since the allowable increase in fuel injection amount is controlled in two stages, control is relatively simple. Note that the method of determining the allowable increase in the fuel injection amount according to the elapsed time after the start of acceleration is not limited to this, for example, the method of calculating the allowable increase in the fuel injection amount according to the elapsed time after the start of acceleration It is also possible to perform more fine-grained control by increasing it in a functional relationship.

In addition, in the above embodiment, the smoothing process during acceleration 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 do so.

Further, in the above embodiments, the present invention is applied to smoothing processing during acceleration, but the scope of application of the present invention is not limited to this, and it can be similarly applied to smoothing processing during deceleration. it is obvious.

Further, in the above embodiments, the present invention is applied to a Kameko control diesel engine for an automobile equipped with a manual transmission, but the scope of application of the present invention is not limited to this.
Auto i1+ equipped with automatic transmission with lock-up gear
It is clear that the invention can be similarly applied to electronically controlled diesel engines for cars and general diesel engines.

As explained above, according to the present invention, it is possible to perform appropriate smoothing processing in accordance with the acceleration/deceleration state.

Therefore, it is possible to reliably reduce acceleration/deceleration shocks, and also to be able to accelerate/decelerate quickly thereafter, thereby providing an excellent effect of being able to obtain a good acceleration/deceleration feeling.

[Brief explanation of the drawing]

FIG. 1 shows fuel injection q of a diesel engine according to the present invention.
FIG. 2 is a partial block diagram showing the configuration of an embodiment of an electronically controlled automobile diesel engine equipped with a manual transmission to which the present invention is applied. FIG. 3 is a block diagram showing the configuration of the electronic control unit used in the embodiment, and FIG. 4 similarly shows the main part of the routine for calculating the fuel injection amount. The flowchart, FIG. 5, shows the steps in the embodiment described above.
FIG. 3 is a diagram showing an example of a state of change in fuel injection amount during acceleration. DESCRIPTION OF SYMBOLS 10... Diesel engine, 12... Fuel injection pump, 22... Rotation degree sensor, 44... Injection nozzle, 54... Accelerator sensor, 58... Electronic control unit h (ECU) . Agent Takaya Ron (and 1 other person)

Claims (2)

[Claims] (1) When determining the fuel injection amount according to engine operating conditions including engine speed and accelerator opening, when accelerating or decelerating, smoothing of the fuel injection amount or accelerator opening is performed to alleviate acceleration/deceleration shocks. In the fuel injection amount smoothing control method for a diesel engine as described above, there is a procedure for determining whether acceleration or deceleration is being performed, a procedure for detecting the elapsed time after the start of acceleration or deceleration when acceleration or deceleration is in progress, and a procedure for determining whether acceleration or deceleration is being performed. The procedure for determining the allowable change amount of the fuel injection amount or accelerator opening according to the elapsed time after the start, and the procedure for calculating the allowable change amount of the fuel injection amount or accelerator opening.
a step of gradually approaching the target value by the permissible change amount;
A fuel injection amount smoothing control method for a diesel engine, the method comprising: (2) The fuel injection amount smoothing control method for a diesel engine according to claim 1, wherein the city-recorded allowable variation is made small at the beginning of acceleration and deceleration.