JPS62294735A - Control device for acceleration time interruption increase of electronically controlled fuel injection internal combustion engine - Google Patents

Abstract

PURPOSE:To improve the characteristic of acceleration, by inhibiting the setting of an interruption fuel injection amount for a decision in the initial time while interruption injection in the initial time of acceleration decision, having bad accuracy of detection, even if an acceleration condition is decided on the basis of the opening change rate of a throttle valve. CONSTITUTION:A control unit 4 calculates the basic fuel injection amount on the basis of detection values of an engine speed sensor 1 and an air flow meter 2 while a correction value on the basis of detection values of a water temperature sensor 3 and a throttle valve opening sensor 7. The control unit 4 calculates an opening change amount on the basis of the detection value of the throttle valve opening sensor 7, and when said change amount is decided two times continuously to increase to a predetermined value or more, interruption injection is performed by searching for its amount on the basis of the water temperature and the opening change amount.

Description

Detailed Description of the Invention 3. Detailed Description of the Invention (Field of Industrial Application) The present invention relates to an electronically controlled fuel injection type internal combustion engine, and more specifically, the present invention relates to an electronically controlled fuel injection type internal combustion engine. The present invention relates to an acceleration interrupt increase control device in which an amount is set.

<Prior Art> There are the following conventional electronically controlled fuel injection internal combustion engines.

That is, the intake air flow I detected by the air flow meter
The basic fuel injection tank Tp (=KxQ/N; is a constant) is calculated from Q and the engine rotational speed N detected by a crank angle sensor, etc., and various corrections are made according to the engine operating state such as the cooling water temperature Tw. After calculating the coefficient C0EF, the air-fuel ratio feedback correction coefficient α, and the correction numerator s based on the battery voltage, the fuel injection amount Ti (=TpXCOEFXα+
Ts) is calculated. For example, in the single point injection system (SP1 method), the two
An injection pulse signal having a pulse width corresponding to the fuel injection 11Ti is outputted to the fuel injection valve in synchronization with an ignition signal or the like every rotation, thereby injecting and supplying fuel to the engine.

By the way, some of the various correction coefficients C0EF include an increase correction coefficient during acceleration, but since the responsiveness deteriorates during acceleration between injection pulses (pulses corresponding to fuel injection lTi), so-called interrupt injection is not performed. (Patent application No. 61-08118)
(See No. 7, etc.)

'Specifically, the opening degree α of the throttle valve is detected at a predetermined sampling time, and when the opening degree changes from an idle state (throttle valve is fully closed) by a predetermined amount or more, it is determined that the engine is in an accelerating state. Then, an interrupt injection pulse signal with a pulse width corresponding to the amount of change Δα in the throttle valve opening detected at the first time of this acceleration determination (multiple pairs of interrupt increased fuel amounts are set in advance depending on the magnitude of the amount of change Δα ()) is inserted into the injection pulse signal corresponding to the fuel injection amount Ti and output.

<Problems to be Solved by the Invention> By the way, as described above, the interrupt fuel injection amount is set in accordance with the amount of change Δα in the opening of the throttle valve during a predetermined sampling time, that is, the rate of change in the opening of the throttle valve. In this case, there will be variations in the detection accuracy of the opening change rate at the first time of acceleration determination, so even if the acceleration state is the same, the amount of fuel increased by the interrupt will be different, and the air-fuel ratio will not reach the desired value. There was a risk of losing control.

That is, as shown in FIG.
s), so if the sampling time Δt is synchronized with the beginning of the opening operation of the throttle valve, the rate of change (Δα) is approximately accurate.

/Δt), but the sampling time Δ
The sampling time Δt includes many idle states within
When the opening operation of the throttle valve starts in the latter half of the period, the amount of change Δα is calculated based on the difference in the opening between the start and end of the sampling period, so even if there is rapid acceleration, the apparent gradually increases Δα within the predetermined sampling time Δ
Therefore, even though it is actually a rapid acceleration state, it is considered to be a slow acceleration state (that is, the opening change rate is Δα2/Δt), and the actual engine demand is There was a risk that the air-fuel ratio would become over-lean due to the interrupt injection being performed in an amount smaller than the actual amount.

The present invention has been made in view of the above problems, and it is an object of the present invention to set an interrupt fuel injection amount during acceleration in accordance with the acceleration state of the engine.

<Means for Solving the Problems> Therefore, in the present invention, as shown in FIG. An electronically controlled fuel injection type internal combustion system comprising: a fuel injection amount setting means for setting a fuel injection amount; and an injection pulse signal output means for outputting an injection pulse signal corresponding to the set fuel injection amount to a fuel injection valve. In an engine, a throttle valve opening change rate detecting means for detecting a rate of change in opening of a throttle valve installed in an intake passage of the engine, and a means for detecting a rate of change in opening of a throttle valve detected by the means for detecting a rate of change in opening of a throttle valve installed in an intake passage of the engine; engine acceleration state determining means for determining that the engine is in an accelerating state and outputting an acceleration determination signal when Interrupt fuel injection amount setting means for setting the injection amount; interrupt fuel injection amount setting prohibition means for prohibiting setting of the interrupt fuel injection amount at the first time of acceleration determination by the engine acceleration state detection means; and the interruption fuel injection amount setting means. an interrupt injection pulse signal output means for outputting an interrupt injection pulse signal corresponding to the interrupt fuel injection (1) set by the above to the fuel injection valve immediately after outputting the acceleration determination signal. I made it.

According to the interruption increase control device during acceleration having such a configuration, even if the detected throttle valve opening change rate exceeds a predetermined value in the opening direction and it is determined that the engine is in an accelerating state, it is determined that the engine is in an accelerating state. When it is determined, the interruption fuel injection amount setting prohibition means prohibits the setting of the interruption fuel injection amount, so that no interruption injection is performed.

That is, when detecting the throttle valve opening change rate, the detection accuracy of the change rate is poor at the first time as shown in Figure 5 (there is a habit of incorrectly determining that the acceleration state is slower than the actual acceleration state). ) Therefore, in this state of poor detection accuracy, interrupt injection is prohibited, and interrupt injection is performed using the interrupt fuel injection amount set based on the second highly accurate opening change rate detection value following this first time. It is something.

<Example> An embodiment of the present invention will be described below based on the drawings.

Figure 2 shows an electronically controlled fuel injection system equipped with an acceleration interrupt increase control device according to the present invention! ! ! , is a configuration block diagram showing an example of an engine.

In this figure, the engine rotation speed N signal which is the output of the rotation speed sensor 1, the engine intake air flow iQ signal which is the output of the air flow meter 2, the engine cooling water temperature Tw signal which is the output of the water temperature sensor 3, and the engine intake air The throttle valve opening α signal, which is the output of the throttle valve opening sensor 7 that detects the opening of a throttle valve (not shown) installed in the passage, is transmitted to a microcomputer configured by an input/output device storage device and a central processing unit. The signals are input to a control unit 4 built in a computer, and the control unit 4 outputs an injection pulse signal and an interrupt injection pulse signal to the drive circuit 6 of the fuel injection valve 5, which are set as described later based on these signals.

That is, as shown in the flowcharts of FIGS. 3 and 4, the control unit 4 includes fuel injection amount setting means, injection pulse signal output means 2, acceleration state determination means 2, interruption fuel injection amount setting means 1, interruption injection pulse A signal output means and an interrupt fuel injection amount setting prohibition means are provided as software. Note that the engine operating state detection means in this embodiment is the rotational speed sensor 1. The air flow meter 2 and the water temperature sensor 3 correspond to the throttle valve opening sensor 7.
and the control unit 4 constitute throttle valve opening change rate detection means.

Next, the operation will be explained according to the flowcharts of FIGS. 3 and 4.

First, the fuel injection amount control routine will be explained based on the flowchart in FIG. Read the rotation speed N and intake air flow iQ.

Then, in step 2, the basic fuel injection amount Tp (-KxQ/N; K is a constant) is calculated from these values in the central processing unit.

In step 3, correction coefficients based on each operating state set in the jQ device are searched from various operating states such as the engine cooling water temperature Tw detected by the water temperature sensor 3, and these correction coefficients are The basic fuel injection amount Tp is corrected by the fuel injection amount Ti (=TpxC
OEF + ・).

When the fuel injection amount Ti is set in step 3, an injection pulse signal corresponding to this fuel injection amount Ti is outputted to the drive circuit 6 of the fuel injection valve 5 in step 4.

The fourth acceleration interrupt injection control routine improves acceleration performance by interrupting the injection pulse signal output to the drive circuit 6 to perform fuel injection.
This will be explained based on the flowchart shown in the figure.

In step 10, the throttle valve opening α detected by the throttle valve opening sensor 7 is read.

In step 11, the opening degree change amount Δα is calculated from the opening degree α read in step 10 and the opening degree α read last time. Note that since this interrupt injection control routine is executed at predetermined time intervals, the amount of change Δα can be regarded as the throttle valve opening change rate.

In step 12, the amount of change Δα calculated in step 11 is
is compared with a predetermined value, and when the amount of change Δα is equal to or greater than the predetermined value on the open side, it is determined that the engine is in an accelerating state, and when the accelerating state is not determined, the engine is directly returned.

When the acceleration state of the engine is determined in step 12, it is determined in step 13 whether or not this acceleration determination is the second time. The second time here means the case where acceleration is determined consecutively from the first acceleration determination, and Y
If it is determined as ES, proceed to the next step 14, and proceed to the next step 14.
When the determination is O, the process returns directly.

This is because, at the first time of acceleration determination, there is a risk of erroneously determining that the acceleration state is slower than the actual acceleration state, as shown in Figure 5. This is intended to avoid setting the interrupt fuel injection amount based on the amount Δα, and in the second and subsequent acceleration determinations following the first time, where there is a risk of erroneous determination,
Since the rate of change in the throttle valve opening degree can be detected substantially accurately, the interrupt injection is performed based on the rate of change in the opening degree detected almost accurately in the second time.

In step 14, the interrupt fuel injection amount T acc is searched from a three-dimensional map of the engine cooling water temperature Tw and the amount of change Δα that has been set and stored in advance. And step 15
An interrupt injection pulse signal corresponding to the interrupt fuel injection ITacc retrieved in is inserted into the injection pulse signal and output to the drive circuit 6 of the fuel injection valve 5 to perform an interrupt injection.

In such interrupt injection control, as described above, interrupt injection is not performed at the first acceleration determination, but interrupt injection is performed when acceleration is determined following the initial acceleration determination. Therefore, the interrupt fuel injection amount T ace is set according to the actual rate of change in throttle valve opening degree, and engine acceleration can be improved by supplying fuel that matches the amount requested by the engine.

<Effects of the Invention> As explained above, according to the present invention, interrupt injection control is not performed in the first acceleration determination with poor protrusion accuracy (of the throttle valve opening change rate), but is performed with good precision in the second consecutive acceleration determination. Since the interrupt injection is executed based on the interrupt fuel injection amount set based on the detected throttle valve opening change rate, the interrupt injection is performed in accordance with the acceleration state of the engine, causing the air-fuel ratio to become over-lean. This has the effect of improving the acceleration of the engine.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram of the present invention, FIG. 2 is a configuration block diagram showing an embodiment of the present invention, FIG. 3 is a flowchart showing a fuel injection control routine in the above embodiment, and FIG. 4 is a flowchart in the same embodiment. FIG. 5 is a flowchart showing the interrupt injection control routine, and is a tight chart for explaining the conventional problems. 1... Rotational speed sensor 2... Air flow meter 3... Water temperature sensor 4... Control unit 5... Fuel injection valve 6... Drive circuit 7...
Throttle Valve Opening Sensor Patent Applicant Japan Electronics Co., Ltd. Agent Patent Attorney Fujio Sasashima Figure 3 Figure 4 Figure 5

Claims (1)

[Claims] an engine operating state detection means for detecting the operating state of the engine; a fuel injection amount setting means for setting a fuel injection amount based on the detected engine operating state; and an injection pulse signal corresponding to the set fuel injection amount. Throttle valve opening change rate detection for detecting the opening change rate of a throttle valve interposed in an intake passage of the engine in an electronically controlled fuel injection internal combustion engine equipped with injection pulse signal output means for outputting to an injection valve. means, engine acceleration state determining means for determining that the engine is in an accelerating state and outputting an acceleration determination signal when the detected rate of change in the opening degree of the throttle valve is equal to or higher than a predetermined value in the opening direction; Interrupt fuel injection amount setting means for setting an interrupt fuel injection amount based on a detected throttle valve opening change rate; and an interrupt for prohibiting setting of an interruption fuel injection amount at the first time of acceleration determination by the engine acceleration state detection means. An electronic control system comprising: a fuel injection amount setting prohibition means; and an interruption injection pulse signal output means for outputting an interruption injection pulse signal corresponding to the set interruption fuel injection amount to the fuel injection valve immediately after outputting the acceleration determination signal. Interrupt increase control device during acceleration for fuel-injected internal combustion engines.