JPS6332137A - Electronic-controlled fuel injector for internal combustion engine - Google Patents

Abstract

PURPOSE:To prevent the variation of fuel injection quantity due to the variation of the revolution speed in an acceleration and deceleration speed operation by calculating the fuel injection quantity on the basis of the weighted average of the revolution speed and the opening degree of a throttle valve when an outside load acts onto an engine. CONSTITUTION:Each detection value of a throttle valve opening degree detecting means A for detecting the neutral state of an automatic transmission, revolution speed detecting means B, and an outside load detecting means C for detecting the neutral position, etc. of an automatic transmission is input into a fuel injection quantity calculating means E. The fuel injection quantity calculating means E detects the intake air quantity from a data map on the basis of the throttle valve opening degree and the weighted average value of the engine revolution speed at the preceding time and the engine revolution speed at this time, when the oatomatic transmission detects the drive position. In case of neutral position, the automatic transmission detects the intake air quantity on the basis of the engine revolution speed at this time and the throttle valve opening degree.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an electronically controlled fuel injection system for an internal combustion engine, and particularly to one that calculates a fuel injection amount based on a throttle valve opening and an engine rotational speed.

(Prior Art) Conventional examples of this type of electronically controlled fuel injection device include the following.

That is, data on the intake air flow rate Q or the basic fuel injection amount 'rp corresponding to each operating range is stored in ROM (or RAM) in advance for each of a plurality of operating ranges in which the throttle valve opening degree α and the engine rotational speed N are used as parameters. Then, data in the corresponding operating range is retrieved from the ROM based on the detected values of the throttle valve opening α and the engine rotational speed N.

When searching for the intake airflow IQ, the basic injection amount Tp (=to -Q/
After calculating N; is a constant), the fuel injection amount Ti=TpX
COEFxα+Ts is calculated.

Then, an injection pulse signal corresponding to the calculated fuel injection if T i is output to the fuel injection valve to inject and supply fuel to the engine.

In addition, when writing the basic injection amount trl in the TpZROM, substitute the basic injection amount `r p retrieved from the throttle valve opening degree α and the engine rotational speed N into the calculation formula for the fuel injection amount `Fi. The fuel injection amount Ti is calculated.

(Problems to be Solved by the Invention) By the way, since fuel injection control is performed with good responsiveness depending on the operating state of the engine, for example, when there is a transition from deceleration to acceleration, the combustion chamber pressure changes depending on the throttle valve opening ( If it follows the change (shown by the solid line in FIG. 4) with good responsiveness, it will rise accordingly. As a result, the engine output attempts to increase rapidly, but the vehicle is unable to respond to the increase with good response, resulting in vehicle torsion vibration (jerky vibration between the forward direction and backward direction of the vehicle9). As a result, the engine rotational speed also fluctuates greatly for a short period of time (Iυ major fluctuation II), as shown in Figure 4, at approximately 400%.
Otsuρ9m,).

Therefore, when the intake air flow rate Q is retrieved from the ROM based on the detected flow nottle valve opening degree and engine rotation speed,
The retrieved intake air flow rate Q also varies depending on the engine rotational speed, as shown in FIG.

For this reason, there is a problem in that the fuel injection iTi also promotes the variable EaJL acceleration shock and acceleration surge in substantially synchronization with the engine rotational speed, as shown in FIG. Further, there is a problem in that a delay in acceleration response or sluggishness occurs due to fluctuations in the fuel injection amount Ti.

Furthermore, when the engine is shifted to deceleration immediately after acceleration, the engine rotational speed fluctuates greatly for a short period of time as shown in FIG. 5, causing the same problem as during acceleration.

Furthermore, the intake air flow rate Q or the basic injection amount Tp is stored in the ROM (or RAM) for each operating region using the predetermined throttle valve opening and the engine rotational speed of a predetermined tiJ as parameters.
Therefore, it is necessary to perform interpolation calculations so that the data near the boundaries of adjacent operating regions differ by a positive 6'. However, if the above interpolation calculation is omitted in order to speed up the calculation speed of the fuel injection amount, the throttle valve opening or engine speed detected during acceleration operation as shown in Fig. If the engine is held near the boundary between the regions for a predetermined period of time, the intake air flow rate Q or the basic injection amount 'rp that is retrieved at this time will vary between the two operating regions, resulting in the same problem as above.

The present invention has been made in view of the above-mentioned circumstances, and it is possible to avoid problems even if engine rotational fluctuations occur during transient operation. Change the amount of t゛1 jet 1! An object of the present invention is to provide an electronically controlled tall fuel injection 9/1 device that can suppress acceleration shock and the like.

ζ Problem, Means for Solving ~> For this reason, the present invention, as shown in FIG.
71 to 71 to detect the valve opening degree [I nottle valve opening degree detection means A, rotation speed 1'32 output means 13 to detect the rotational speed of the engine, and whether or not the outside is acting on the engine. The external load detection means C detects the external load, and the weighted averaging means calculates the weighted average of the engine rotational speed of the detected turn or the previously weighted averaged engine rotational speed and the currently detected engine rotational speed. When the external load is applied, the fuel f1 injection amount is calculated according to the weighted average engine speed and the detected throttle valve opening, and when the external load is not applied, the fuel injection ratio is calculated. The fuel injection amount calculation means 1 calculates the fuel injection amount according to the engine rotational speed and the throttle valve opening, and the fuel injection valve F is operated on the driving side f' according to the calculated fuel injection amount.
A drive control means G for JO is provided.

In this way, when an external load is applied to the engine, the fuel injection amount is calculated based on the weighted average of the engine rotation speed, and the actual engine rotation speed changes during acceleration/deceleration operation. This suppresses fluctuations in the fuel injection amount even when the engine is in use.

<Example> An example of the present invention will be described below with reference to FIGS. 2 and 3.

In the figure, it's not from a microcomputer, etc.
l? 'Ill device l detects the engine rotational speed; rotational speed sensor 12 as rotational speed detection means;
] 71 - Detects the opening of the throttle valve (not shown) A throttle valve opening sensor 3 serves as a throttle valve opening detection means, and a neutral switch 1 serves as an external load detection means for detecting the presence or absence of a neutral state. Detection signals are inputted from the engine and the water temperature sensor 5 that detects the engine cooling water temperature.

The control device 1 operates according to the flowchart shown in FIG. 3 and outputs a drive pulse signal to the fuel injection valve 6 via the drive circuit 7.

Here, the control device 1 constitutes a weighted average means and a fuel injection amount calculation means, and the control device 1 and the drive circuit 7 constitute a drive control means.

Next, the operation will be explained according to the flowchart shown in FIG.

At Sl, various signals such as the throttle valve opening 32 detected by the throttle valve opening sensor 3 and the engine rotational speed N detected by the rotational speed sensor 2 are read.

In S2, it is determined whether the neutral switch 4 is ON or not. If YES, the process proceeds to S3; if NO, the process proceeds to S4. At this point, neutral switch 4 is turned on (YE
S), it is determined that the engine side and the driving wheel side are disconnected in the neutral state, and no external load (driving force) is acting on the engine, and the neutral switch 4 is OFF.
When the result is (No), it is determined that the engine side and the driving wheel side are connected and that an external load is acting on the engine. Note that the external load may be detected from the on/off state of the clutch and the presence or absence of the neutral state.

In S3, 3 of the intake air flow rate Q stored in the ROM is calculated based on the detected throttle valve opening α and engine rotational speed N.
Data on the intake air flow IQ corresponding to the relevant operating region is retrieved from the dimensional map table.

In S4, a weighted average value NA of the detected previous engine rotational speed N, -1 and the current engine rotational speed Ni is calculated using the following equation.

In S5, the intake air flow f is calculated from the ROM based on the weighted average engine speed NA and the detected throttle valve opening.
Search fi Q A.

In S6, the basic injection amount 'rp is calculated and set by the following formula based on the intake air flow rates Q and QA retrieved in S3 or S5 and the detected engine rotational speed N.

T p = K-Q (QA) / N (K is a constant) In S7, various correction coefficients C0FF to be multiplied by the Tp are calculated based on the engine cooling water temperature and the like.

In S8, the voltage correction numerator s is calculated based on the voltage value of the battery.
Set.

In S9, the final fuel injection amount Ti is calculated using the following equation.

Ti=TpXCOEF+Ts In S10, a drive pulse signal having a pulse width corresponding to Ti calculated in S9 is output to the fuel injection valve 6 via the drive circuit 7.

As a result, the fuel injection valve 6 is energized for a predetermined period of time, and fuel in an amount corresponding to Ti is injected and supplied to the engine.

As explained above, since the previous detected engine rotation speed and the current engine rotation speed are weighted averaged,
Even if actual engine rotational fluctuations occur during acceleration/deceleration operation, the weighted average engine rotational speed will be lower than the actual engine rotational speed in areas where the fluctuation is high, while it will be lower than the actual engine rotational speed in areas where the fluctuation is low. higher than the speed. As a result, the fluctuation force of the weighted average engine rotation speed is suppressed more than the fluctuation force of the actual engine rotation speed, so the intake air searched based on the weighted average engine rotation speed and the detected throttle valve opening degree is suppressed. Fluctuations in flow rate can be suppressed. Therefore, it is possible to suppress fluctuations in the fuel injection amount during acceleration/deceleration operation, reduce shocks and surges during acceleration/deceleration, and suppress response delay or breathlessness during acceleration.

Note that the weighted average of the previous engine rotation speed and the detected current engine rotation speed may be weighted averaged.

<Effects of the Invention> As explained above, the present invention determines the fuel injection amount based on the weighted average of the engine rotational speed and the detected throttle valve opening when an external load is acting on the engine. Since it is calculated, even if the actual engine speed changes during acceleration/deceleration operation, it is possible to suppress fluctuations in the fuel injection amount11r11.
Acceleration shock.

Surges, etc. can be suppressed.

[Brief explanation of the drawing]

Fig. 1 is a diagram corresponding to the claims of the present invention, Fig. 2 is a configuration diagram showing an embodiment of the present invention, Fig. 3 is a diagram corresponding to the claims of the same,
FIGS. 4 to 6 are diagrams for explaining the drawbacks of the conventional technology.

Claims (1)

[Claims] Throttle valve opening detection means for detecting the throttle valve opening of the engine; rotational speed detection means for detecting the rotational speed of the engine; external load detection means for detecting whether an external load is acting on the engine; weighted averaging means for weighted averaging the detected previous engine rotational speed or the previous weighted average engine rotational speed and the currently detected engine rotational speed; Fuel injection amount calculation means that calculates the fuel injection amount according to the engine rotation speed and the detected throttle valve opening degree, and calculates the fuel injection amount according to the detected engine rotation speed and the throttle valve opening degree when no external load is applied. What is claimed is: 1. An electronically controlled fuel injection device for an internal combustion engine, comprising: and a drive control means for driving and controlling a fuel injection valve according to the calculated fuel injection amount.