JPS6245950A - Electronic control fuel injection device for car internal combustion engine - Google Patents

Abstract

PURPOSE:To make engine output follow on a car speed so favorably as well as to reduce a car vibration to be produced at the time of accelerating drive, by controlling an accelerating increment so as to be delayed for the specified time long at the time of the said accelerating drive immediately after decelerating drive. CONSTITUTION:When an accelerating drive state of an engine A is detected by an accelerating drive state detecting device C, an increment fuel injection quantity at acceleration is set by an accelerating increment fuel setting device D. And, when a decelerating drive state of the engine A is detected by a decelerating drive state detecting device E and a fact that it shifts to the accelerating drive state immediately after decelerating drive is judged by a judging device F, a total fuel injection quantity is calculated by an operational device G with only a fuel injection quantity at steady driving to be found by a fuel injection quantity setting device B, for the specified time long since the accelerating drive has started. And, afterward, on the basis of the fuel injection quantity at steady driving and the increment fuel injection quantity at acceleration, a total fuel injection quantity is calculated, and a fuel injection valve H is controlled on the basis of the calculated result.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industry> Second Field of Application The present invention relates to an electronically controlled fuel injection device for a vehicle internal combustion engine.

<Prior Art> The following is a conventional example of an electronically controlled fuel injection device for a vehicle internal combustion engine.

That is, from the intake air flow rate Q detected by an air flow meter etc. and the engine rotation speed N, the basic injection amount Tp=Kx
After calculating Q/N (K is a constant), various correction coefficients C0EF mainly depending on water temperature, air-fuel ratio feedback correction coefficient α, and correction coefficient Ts depending on battery voltage, the fuel injection amount Ti during steady operation is calculated. -TpX
Calculate C0EFxα+Ts.

For example, in a single point injection system (hereinafter referred to as SP1 system), the fuel injection valve MJ
It outputs an injection pulse signal of pulse 11 corresponding to i to supply fuel to the engine.

Furthermore, during acceleration operation, the increased fuel injection amount during acceleration is calculated from the rate of change of the intake throttle valve opening, etc., and the increased fuel injection amount is added to the fuel injection amount Ti, thereby increasing the amount of fuel during acceleration and increasing the engine output. increase

Incidentally, the increase in fuel consumption during acceleration can also be performed by interrupt injection, which is performed by inserting an injection pulse during acceleration into a normal injection pulse signal.

<Problems to be Solved by the Invention> However, in such conventional electronically controlled fuel injection systems, fuel injection control is performed with good responsiveness according to the operating state of the engine. If you do this, there are the following problems.

In other words, since fuel injection control is performed with good responsiveness depending on the engine operating state, when the operation shifts from deceleration to acceleration, the combustion chamber pressure changes depending on the intake throttle valve opening (see the solid line in Fig. 4). It follows changes in the solid line (shown by the solid line) with good responsiveness and rises rapidly. Therefore, as the engine output increased rapidly, vehicle torsional vibration (jerky vibration between the forward direction and backward direction of the vehicle, hereinafter referred to as vehicle vibration) increased as shown by the solid line in Figure 4, deteriorating drivability. .

The present invention was developed in response to the above-mentioned circumstances, and provides an electronically controlled fuel injection device for a vehicle internal combustion engine that suppresses vehicle vibrations occurring when transitioning from deceleration to acceleration by 4V; b&. Let's call it "one target."

Means for Solving the Problems> For this reason, the present invention provides fuel injection amount setting means B for setting the fuel injection amount during steady operation based on the operating state of the engine, as shown in FIG. , an acceleration driving state detection means C for detecting an acceleration driving state, an acceleration driving increase fuel setting means C for setting an increased fuel injection amount during acceleration according to the detected acceleration driving state, and a deceleration driving state detecting means C for detecting a deceleration driving state. A driving state detecting means E, a determining means F that determines from these detecting means C and E whether or not the driving state has shifted to an accelerated driving state immediately after decelerating driving, and a determining means F that determines whether or not the driving state has shifted to an accelerating driving state immediately after decelerating driving; For a predetermined period of time from the start of operation, total fuel injection is performed using only the fuel injection amount during steady operation! After calculating I=J■, the total fuel injection amount is calculated based on the fuel injection amount during steady operation and the increased fuel injection amount during acceleration, and in other operating regions, the fuel injection amount during steady operation and acceleration are calculated. calculation means G that calculates the total fuel injection amount based on the calculated total fuel injection amount, and drive pulse output means I that outputs an injection pulse signal corresponding to the calculated total fuel injection amount to the fuel injection valve I tried to prepare.

<Function> In this way, when shifting to acceleration operation immediately after deceleration operation, the total fuel injection amount is calculated only from the fuel injection amount during steady operation without adding the increased fuel injection amount at a predetermined speed, and during acceleration. This eliminates the sudden increase in engine output in the early stages, thereby suppressing vehicle vibration.

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

In FIG. 2, a control device 1 consisting of, for example, a microcomputer receives an ignition signal (rotation speed signal) output from an ignition coil 2, an intake air flow rate signal output from an air flow meter 3, and an output from a water temperature sensor 4. The intake throttle valve opening signal is output from the intake throttle valve opening sensor 5, the fuel temperature signal is output from the fuel temperature sensor 6, and the vehicle speed sensor 7 outputs from the vehicle speed sensor 7, which detects the vehicle speed. A vehicle speed signal from the engine and an ON/OFF signal from an idle switch 8 that detects the idle operating state are input. The control device 1 operates according to flowchart I shown in FIG. 3 and outputs an injection pulse signal to the drive circuit 10 of the fuel injection valve 9.

Here, the control device 1 constitutes a fuel injection amount setting means, an increase fuel amount setting means during acceleration, a determination means, and a calculation means, and the control device 1 and the drive circuit 10 constitute a drive pulse output means. In addition, the idle switch 8 and the intake throttle valve opening sensor 5
constitute an acceleration driving state detection means and a deceleration driving state detection means, respectively.

Next, the operation will be explained based on the flowchart shown in FIG.

Various signals such as an ignition signal, an intake air flow rate signal, a cooling water temperature signal, a throttle valve opening signal, a fuel temperature signal, and a vehicle speed signal are read at Sl. Then, at S2, the ignition coil 2
After calculating the basic injection amount from the engine rotational speed N obtained from the ignition signal and the intake air flow rate Q detected by the air flow meter 3, fuel injection during steady operation is corrected from various operating conditions including cooling water temperature etc. The quantity Ti is calculated in the same manner as in the conventional example.

In S3, it is determined whether the idle switch 8 has changed from ON to OFF, and if it is maintained ON or OFF, it is determined that the operating state is steady, and the process advances to S4 to read out the fuel injection amount Ti calculated in S2. If YES, it is determined that the vehicle is in an accelerated driving state, and the process proceeds to S5, and it is determined whether the vehicle speed detected by the vehicle speed sensor 7 is less than a predetermined value. If No, that is, it is less than a predetermined value, the process proceeds to S4.

If YES, the process proceeds to S6 and calculates the opening speed of the intake throttle valve from the intake throttle valve opening signal from the intake throttle valve opening sensor 5.

Then, the increased twist I injection amount Tα during acceleration is retrieved from the memory based on the opening speed of the intake throttle valve calculated in S6. The memory stores an amount of fuel (2) to be increased during acceleration so as to increase in proportion to the opening speed of the intake throttle valve.

In S8, based on the opening speed of the intake throttle valve, it is determined whether the operation is an acceleration operation immediately after a deceleration operation, and when it is determined that the operation is an acceleration operation immediately after a deceleration, the process proceeds to S9 and a timer starts counting. When it is determined that the driving is accelerated, the process proceeds to Sll, which will be described later.

In SIO, it is determined whether a predetermined time has elapsed from the time when the timer starts counting, that is, from the start of acceleration operation, and if No, the process proceeds to S4, and when the predetermined time has elapsed, S
Proceed to ll.

At Sll, the fuel injection amount (Ti) during steady operation and the increased fuel injection amount Tα during acceleration are added to obtain the total fuel injection amount.

In SI2, an injection pulse signal corresponding to the fuel injection amount T1 during steady operation determined in S4 or the total fuel injection amount during acceleration operation determined in Sll is sent to the fuel injection valve 9 via the drive circuit 10. Output.

In this way, during acceleration operation immediately after deceleration operation, fuel injection control is performed based on the fuel injection amount Ti during steady operation without adding the increased fuel injection amount Tα at the predetermined speed for a predetermined time, and then the fuel injection hIT i is Increased fuel injection amount T during acceleration
Since fuel injection control is performed by adding α, the combustion chamber pressure at the beginning of acceleration operation due to misfire etc. is lower than before as shown by the broken line in Figure 4 (after the predetermined time, the pressure increases with a delay in acceleration operation) )do. Therefore, since the engine output during acceleration increases after the acceleration operation, the vehicle speed follows the increase in engine output well, so the vehicle vibration is much greater than before, as shown by the broken line in Figure 4. It is possible to reduce this and improve drivability.

Incidentally, since the change in vehicle speed is small during acceleration operation other than immediately after deceleration operation, vehicle vibration is extremely small, and drivability does not deteriorate even if the amount increase during acceleration is not delayed. Further, the present invention can also be applied to interrupt injection. The presence or absence of acceleration operation may be determined based on the opening speed of the intake throttle valve.

<Effects of the Invention> As explained above, in the present invention, during acceleration operation immediately after deceleration operation, the increase during acceleration is delayed by a predetermined time, so that the engine output at the initial stage of acceleration lags behind the acceleration operation. As the engine output increases, the vehicle speed follows the engine output well. As a result, vehicle vibration is reduced by 11 times more than in the past, and drivability can be improved.

[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, and Fig. 3 is a flow diagram of the same as above.
, FIG. 4 is a diagram for explaining the effects of the conventional example and the embodiment. 1...Control device...Intake throttle valve opening sensor 8...
・Idle switch 9...Fuel injection valve 10...
Drive circuit patent applicant Japan Electronics Co., Ltd. Agent Patent attorney Tomiji Sasashima 1llff2133 Figure 101 Figure 3 Part 2

Claims (1)

[Claims] A fuel injection amount setting means for setting a fuel injection amount during steady operation based on the operating state of the engine, an acceleration operation state detection means for detecting an acceleration operation state, and an increased amount of fuel during acceleration according to the detected acceleration operation state. Acceleration increase fuel setting means for setting the injection amount, deceleration operation state detection means for detecting the deceleration operation state, and determination means for determining from these detection means whether or not the acceleration operation state has shifted immediately after the deceleration operation; When it is determined that the acceleration operation state has shifted immediately after the deceleration operation, the total fuel injection amount is calculated using only the fuel injection amount during the steady operation for a predetermined period of time from the start of the acceleration operation, and then the total fuel injection amount is calculated based on the fuel injection amount during the steady operation and the acceleration operation. calculation means for calculating the total fuel injection amount based on the fuel injection amount during steady operation and the fuel injection amount during acceleration in other operating regions; 1. An electronically controlled fuel injection device for a vehicle internal combustion engine, comprising: a drive pulse output means for outputting an injection pulse signal corresponding to the calculated total fuel injection amount to a fuel injection valve.