JPS6223546A - Electronically controlled fuel injection device for internal-combustion engine - Google Patents

Abstract

PURPOSE:To improve a response characteristic of acceleration in an engine, by providing a comparing means which compares outputs from an acceleration correction coefficient setting means and a slow acceleration correction coefficient setting means to output a larger correction coefficient as a correction signal. CONSTITUTION:A device provides an acceleration correction coefficient setting means E and a slow acceleration correction coefficient setting means F which respectively output correction coefficients in accordance with an engine operative condition in that time through an acceleration detecting means C and a slow acceleration detecting means D. A correction coefficient comparing means G, comparing outputs from the both setting means E, F, outputs a larger correction coefficient as a correction signal. A pulse output means H outputs a fuel injection pulse in which a fuel injection signal, output from an injection quantity setting means A, is corrected on the basis of the correction signal output from the comparing means G. In this way, the device, avoiding a hesitation in an engine when it is slow accelerated, enables a response characterristic of acceleration in the engine to be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to an electronically controlled fuel injection device for an internal combustion engine, and more particularly to a device for reducing hesitation (feeling of sluggishness) during acceleration operation.

<Prior art> In an electronically controlled fuel injection system for an internal combustion engine, fuel injection is generally performed based on the intake air flow rate detected by an intake air flow rate measuring window (air flow meter) and the engine speed detected from the ignition signal of the ignition coil. (The main injection amount is determined, and the fuel = 1 injection signal obtained by appropriately correcting the basic injection amount corresponding to this basic injection amount is proportional to the rotation period of the engine, for example by synchronizing it with the ignition signal. By outputting the output to the drive circuit of the city magnet type fuel injection valve t to drive the injection valve at the cycle, the optimal amount of fuel is supplied to the engine.

By the way, hesitation that occurs during acceleration is often seen in single-point injection systems in which fuel is injected at one point in the intake passage upstream from the intake throttle valve, and the hesitation that occurs during acceleration is often seen in single-point injection systems that inject fuel at one point in the intake passage upstream from the intake throttle valve. The longer the time, the more noticeable it becomes. This is because it takes a long time for the injected fuel to actually reach the combustion chamber, and in order to reduce this hesitation, the fuel injection amount is increased when engine acceleration is detected. I was doing it.

However, the resolution of the throttle opening sensor that outputs a signal responsive to the opening of the intake throttle valve is approximately 0.18 deg, and the output of the throttle opening sensor is The resolution was set to 1.6 degrees to avoid malfunctions due to noise. FIG. 5 shows the characteristic causes of the acceleration judgment limit.

<Problems to be Solved by the Invention> However, in an electronically controlled fuel injection system equipped with such a conventional acceleration increase correction mechanism, the opening degree of the intake throttle valve is 1.
Unless the change is greater than 6 degrees, it is not determined that the acceleration state yE is present. Therefore, it takes 1.5 seconds for the intake throttle valve to go from fully open to fully open (80/L, SX 30m5
) so that it is not considered an acceleration if it takes longer than
For example, as shown by the broken line in Figure 5, from fully closed to fully open,
．． During slow acceleration operation, which requires 5 to 7 seconds, the expected increase in acceleration is not carried out, so there is a problem in that hesitation occurs due to a delay in fuel supply.

The present invention has been made in view of these conventional problems, and is capable of achieving a desired increase in acceleration not only during sudden acceleration and normal acceleration, but also under slow acceleration conditions that were not detected in the past. The purpose is to improve acceleration response by reliably executing the fuel injection system and reducing hesitation during acceleration of an internal combustion engine equipped with an electronically controlled fuel injection system.

Means for Solving the Problems> In order to achieve such an object, the present invention provides an injection amount setting means A that outputs a fuel injection signal according to the engine operating state at a predetermined cycle, as shown in FIG. and a throttle opening sensor B that outputs a signal responsive to the opening of an intake throttle valve installed in the intake passage, and detects the acceleration operation of the engine from the amount of change in the output of the throttle opening sensor B per unit time. an acceleration detection means C; a slow acceleration detection means for detecting a slow acceleration operation of the engine based on the amount of change in the output of the throttle opening sensor B per a predetermined time longer than the unit time; and the acceleration detection means C.
and acceleration correction coefficient setting means E and slow acceleration correction coefficient setting means for outputting correction coefficients according to the engine operating state at that time when acceleration operation and slow acceleration operation of the engine are detected through the slow acceleration detection means E and the slow acceleration detection means. means F, a comparison means G for comparing the outputs of the acceleration correction coefficient setting means E and the slow acceleration correction coefficient setting means F, and outputting the larger correction coefficient as a correction signal, and an output from the injection amount setting means A. pulse output means H for outputting a fuel injection pulse corrected based on the supplementary iE signal output from the comparison means G; The structure includes a driving means J for driving the fuel injection valve I of the formula.

<Operation> With such a configuration, not only sudden acceleration and normal acceleration, but also slow acceleration, which could not be detected in the past, can be reliably detected and the desired acceleration increase can be executed. The present invention is designed to reduce hesitation during acceleration of an internal combustion engine equipped with a controlled fuel injection device, thereby improving acceleration response.

<Example> An example of this invention '51 will be described below.

FIG. 2 is a block diagram showing an embodiment of an electronically controlled fuel injection device for an internal combustion engine according to the present invention. In this diagram,
The ignition coil I outputs the ignition zero (rotation speed signal), the airflow meter 2 outputs the intake air flow II signal,
A cooling water temperature signal that is the output of the water temperature sensor 3, a throttle valve opening signal that is the output of the throttle opening sensor 4, and a fuel temperature signal that is the output of the fuel temperature sensor 5 are supplied to a control unit 6 that has a built-in microcomputer. Based on these various signals, the control unit 6 outputs an injection pulse set as described later to the drive circuit 8 of the fuel injection valve 7.

That is, during steady operation of the engine, the control unit 6 generates a basic pulse Tp (=
KXQ/N) is set, and a fuel injection pulse Ti with a pulse width obtained by correcting this by the cooling water temperature, etc. is output to the drive circuit 8 to drive the fuel injection valve 7, thereby synchronizing with one ignition value number. Perform the fuel injection.

On the other hand, the amount of change Δα per unit time (for example, 30+ss) in the throttle valve opening α detected by the throttle opening sensor 4
is larger than a predetermined value (for example, 1.6 degrees), it is determined that acceleration is occurring, and an increase correction described later is performed, thereby ensuring acceleration responsiveness during sudden acceleration and normal acceleration. Further, even if the amount of change Δα per unit time is smaller than a predetermined value, the predetermined time longer than the unit time (for example, 150 as
) is larger than a predetermined value (for example, 1.8 deg), it is determined that the acceleration is slow, and the increase correction described later is executed to reduce hesitation during slow acceleration. The opening sensor 4 and the control unit 6 constitute an acceleration detection means C and a slow acceleration detection means.

Next, specific fuel injection control by the control unit 6 will be explained according to the flowchart of FIG. 3. Third
In the figure, Sl indicates the engine speed N obtained from the ignition signal from the ignition coil 1, the intake air flow rate Q obtained from the signal from the air flow meter 2, and the intake throttle valve based on the opening signal from the throttle opening sensor 4. The opening degree α is input, and the process proceeds to step S2, where a basic pulse Tp (=KXQ/N) corresponding to the basic injection amount is calculated.

Next, in step S3, the current throttle valve opening α and the unit time (
30ms) The current acceleration Aα is calculated based on the previous throttle valve opening α0, and the process proceeds to step S4, where this acceleration Δ
The acceleration correction coefficient @KACC responsive to α is read from the MAP, and the process proceeds to step S5. Figure 5 shows the limits of acceleration detection.

In step S5, the acceleration Aα per predetermined time (150ms) longer than the unit time (30ms) is calculated in the same manner as described above, and the slow acceleration correction coefficient K responds to this acceleration Aα.
The ACCS is read from the MAP in step S6.

Figure 4 shows the limits of slow acceleration detection. In this case, the control unit 6 functions as the acceleration detection means C and the slow acceleration detection means.

Further, in step S7, the acceleration correction coefficient KACC and the slow acceleration correction coefficient KAGCS are compared, and the larger correction coefficient is outputted to the pulse output means H, and in step S8 or S9.
The basic injection pulse T output from the injection amount setting means A at
A fuel injection pulse Ti is calculated by multiplying P by the above correction coefficient (KACC or KACCS) and output. In this case, the control unit 6 functions as the pulse output means H.

Incidentally, the correction coefficients KACC and KAC:O9 are Δα
It has a characteristic that it increases as the output of the water temperature sensor 4 increases and decreases as the N increases, but decreases as the output of the fuel temperature sensor 5 increases. Further, when it is determined by the acceleration detection means C and the slow acceleration detection means that there is neither acceleration nor slow acceleration, that is, when it is determined that steady normal rotation is occurring, both of the correction coefficients KACC and KACC9 are 1'', the basic injection pulse TP is output as the fuel injection pulse Ti. However, even in this case, it is desirable to correct it according to the outputs of the water temperature sensor 3 and the fuel temperature sensor 5.

Although the above embodiment describes the case where the width of the injection pulse is corrected to increase during acceleration, it goes without saying that the present invention can be applied to the case where the width of the injection pulse is increased during acceleration.

<Effects of the Invention> As explained above, according to the present invention, the state of change in the opening of the intake throttle valve is detected for each width interval as in the conventional case, and it is determined whether or not accelerating operation is being performed. Since changes in the intake throttle valve opening are detected at predetermined time intervals longer than this unit time to determine whether or not the state is in a slow acceleration state, responsiveness during sudden acceleration may be impaired. Since it is possible to accurately detect slow acceleration and execute the specified acceleration increase, it is possible to avoid the conventional hesitation during slow acceleration and improve the engine's acceleration response. .

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing the configuration of the present invention, Fig. 2 is a block diagram showing the configuration of an embodiment of the present invention, Fig. 3 is a flowchart showing the control routine, and Fig. 4 is the detection limit of slow acceleration. FIG. 5 is a characteristic diagram between the time limit capability of the control unit and the resolution source showing the detection limit of acceleration. FIG.

Claims (1)

[Claims] an injection amount setting means that outputs a fuel injection signal according to the engine operating state at a predetermined cycle; a throttle opening sensor that outputs a signal responsive to the opening of an intake throttle valve installed in the intake passage; acceleration detecting means for detecting accelerated operation of the engine from the amount of change in the output of the throttle opening sensor; A slow acceleration detection means for detecting, and an acceleration correction for outputting a correction coefficient according to the engine operating state at that time when acceleration operation and slow acceleration operation of the engine are detected through the acceleration detection means and the slow acceleration detection means. a coefficient setting means and a slow acceleration correction coefficient setting means; a comparison means for comparing the outputs of the acceleration correction coefficient setting means and the slow acceleration correction coefficient setting means and outputting a larger correction coefficient as a correction signal; and the injection amount setting means. pulse output means for outputting a fuel injection pulse that is obtained by correcting the fuel injection signal output from the comparison means based on the correction signal output from the comparison means; An electronically controlled fuel injection device for an internal combustion engine, comprising: a drive means for driving an injection valve.