JPS62107249A - Acceration increment control device for automobile engine of fuel injection type - Google Patents

Abstract

PURPOSE:To provide proper accelerating performance by making a correction to a fuel feeding increment which is retrieved based on a detected manipulated variable for acceleration, based on an actually detected accelerating condition such that an initial acceleration will be a target acceleration. CONSTITUTION:In the titled engine A, a drive pulse signal corresponding to a fuel injection which is set by a setting means B based on engine operating conditions, is outputted to fuel injection valves C by a drive pulse signal output means D. And a manipulated variable for acceleration is detected by an acceleration detecting means F, and a fuel feeding increment for acceleration corresponding to the manipulated variable is retrieved by a retrieval means based on a command from a memory means, and the increment in a form of an interrupting pulse signal, is interrupted into the drive pulse signal in the initial stage of acceleration so as to be outputted to the fuel injection valve C. In this case, an actual accelerating condition of a vehicle is detected by a detecting means I, and a correction is made to the fuel feeding increment for acceleration by a correction means J based on the detected accelerating condition such that an initial acceleration will be a target acceleration.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to an acceleration increase control device for a fuel-injected internal combustion engine for a vehicle, and more particularly to an acceleration increase control device that increases acceleration amount at an early stage of acceleration.

<Prior Art> The following is a conventional example of an electronically controlled fuel injection type internal combustion engine (see Utility Model Application No. 60-066558).

That is, the basic injection tTp-KXQ is determined based on the detected intake air flow rate Q of the intake air flow meter that detects the intake air flow rate based on the output voltage of a hot wire resistor installed in the intake passage and the engine rotational speed N.
/N (K is a constant), as well as various correction coefficients C0EF mainly depending on water temperature, air-fuel ratio feedbank correction coefficient α, and correction coefficient Ts depending on battery voltage, fuel injection 11Ti- during steady operation is calculated. TpXC
Calculate OEF×α+Ts.

Then, in synchronization with the ignition signal and the like, a drive pulse signal having a pulse width corresponding to the fuel injection amount Ti is outputted to the fuel injection valve to supply fuel to the engine.

In addition, during acceleration operation, the fuel injection ITi is multiplied by the acceleration increase coefficient obtained from the rate of change of the intake throttle valve opening, etc. to set the increase fuel amount during acceleration, and an interrupt with a pulse width corresponding to the increase fuel amount is set. Acceleration is increased by so-called interrupt injection, in which a pulse signal is inserted between the drive pulse signals and an increased amount of fuel is injected at the beginning of acceleration.

(Problem to be Solved by the Invention) However, in such a conventional acceleration increase control device, in order to obtain optimal acceleration characteristics, a fuel injection valve whose fuel injection characteristics or intake air flow rate detection characteristics are average values is used. Alternatively, it is compatible with the intake air flow meter, and the increased fuel amount during acceleration is set based on the rate of change of the intake throttle valve opening, etc., so the increased fuel amount during acceleration is determined by product variations in the fuel injection valve or intake air flow rate needle. For example, the air-fuel ratio based on the amount of fuel becomes leaner.

Specifically, if the fuel injection characteristics worsen and the increased fuel amount during acceleration becomes lower than normal, the intake air flow rate characteristics of the intake air flow meter will deteriorate, and the intake air flow rate detected by the actual intake air flow rate (shown by the solid line in Figure 11) will deteriorate. The air flow rate (shown by the broken line in FIG. 11) decreases.

As a result, the combustion performance of the engine decreases or a misfire occurs, and as shown in Figure 11, the indicated mean effective pressure in the combustion chamber abnormally decreases (A in Figure 11) at the beginning of acceleration, and the acceleration of the vehicle decreases. The problem is that the engine speed decreases (deceleration state B in FIG. 11), and in the worst case, an engine stall occurs.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an acceleration increase control device that can prevent a decrease in combustion performance or a misfire even if interrupt injection is performed at an early stage of acceleration.

Means for Solving the Problems> For this reason, the present invention sets an appropriate amount of increased fuel during acceleration even if there are manufacturing variations in fuel injection valves, etc., and prevents a decrease in combustion performance or misfire during acceleration. It is characterized by

As shown in FIG. 1, the first invention includes a fuel injection amount setting means B that sets the fuel injection amount during steady operation based on the operating state of the engine A, and a drive corresponding to the set fuel injection amount. The fuel injection valve C is synchronized with the engine rotation using the pulse signal.
a drive pulse output means for outputting a drive pulse to a drive pulse, a storage means E for storing an increased fuel amount during acceleration set in correspondence with an acceleration operation amount, an acceleration detection means F for detecting an acceleration operation amount, and a detected acceleration operation. a retrieval means G for retrieving an increased amount of fuel during acceleration from the storage means according to the amount of fuel; and an interrupt pulse signal corresponding to the retrieved increased amount of fuel during acceleration inserted between the drive pulse signals at an early stage of acceleration. and an interrupt pulse output means H for outputting to the fuel injection valve, a vehicle acceleration state detection means I for detecting the actual acceleration state of the vehicle.
a correction means J that corrects the increased fuel amount during acceleration so that the acceleration at the initial stage of acceleration becomes the target acceleration based on the detected acceleration state; An update method for rewriting the .

As shown by the broken line in FIG. 1, the second invention includes a pressure detection means for detecting the combustion pressure of engine A, and calculates the indicated average effective pressure per stroke at the initial stage of acceleration based on the detected combustion pressure. a calculation means M for calculating, a correction means N for correcting the increased fuel amount during acceleration so that the calculated indicated average effective pressure becomes the target indicated average effective pressure, and the storage means for storing the corrected increased fuel amount during acceleration. An update means for rewriting data is provided.

In this manner, by updating the increased fuel amount during acceleration stored in the storage means, an optimum increase in fuel amount during acceleration is achieved and a decrease in combustion performance during acceleration or misfire is prevented.

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

FIG. 2 shows an embodiment of the first invention.

In the figure, a vehicle 1 is provided with an acceleration sensor 2 consisting of a piezoelectric element or the like as vehicle acceleration state detection means for detecting the acceleration of the vehicle 1, and the output voltage of the acceleration sensor 2 is transferred to an amplifier 3 and an A/D converter. The signal is inputted via a device 4 to a control device 5 consisting of, for example, a microcomputer.

The control device 5 also receives a rotation speed signal output from the rotation speed sensor 6, an intake air flow rate signal output from the air flow meter 7, a cooling water temperature signal output from the water temperature sensor 8, and an acceleration detection means. The intake throttle valve opening signal outputted from the intake throttle valve opening sensor 9 is input. The control device 5 operates according to the flowcharts shown in FIGS. 3 to 5 and outputs a pulse signal to the fuel injection valve 10 via the drive circuit 11.

Here, the control device 5 is fuel injection amount setting means.

It also functions as a storage means (RAM of the control device 5), a search means, a correction means, and an update means, and the control device 5 and the drive circuit 11 constitute a drive pulse output means and an interrupt pulse output means.

Next, the operation will be explained according to the flowcharts shown in FIGS. 3 to 5.

First, the fuel injection amount control routine will be explained based on the flowchart in Fig. 3. In Sl, various signals such as the rotational speed signal N, intake air flow rate signal Q, cooling water temperature signal, intake throttle valve opening signal, etc. are read. . In S2, basic injection is performed based on engine speed and intake air flow rate! jtTp (=K・Q/N)
After calculating, in S3, the fuel injection amount Tt during steady operation corrected from various operating conditions including the cooling water temperature etc. is calculated in the same manner as in the conventional example.

Then, in S4, a drive pulse signal corresponding to the fuel injection amount T1 is output to the fuel injection valve 10 via the drive circuit 11 at a predetermined timing in synchronization with the engine rotation to perform a fuel injection operation.

Next, the acceleration increase during acceleration operation will be explained according to the flowchart shown in FIG. 4. In S11, various signals such as a cooling water temperature signal and an intake throttle valve opening signal are read.

At Sl2, the rate of change Δα of the intake throttle valve opening is calculated from the intake throttle valve opening signal, and at 313, it is determined whether or not it is an acceleration operation from the calculated rate of change Δα of the intake throttle valve opening. Proceed to S14, and if NO, proceed to Sll.

In S14, RA is set under the same conditions as the rate of change Δα (operated amount).
Search for the increased fuel amount Tα during acceleration from M (or ROM). The increased fuel amount Tα during acceleration is set to increase in accordance with the increase in the rate of change Δα, as shown by the solid line in FIG. Here, the increased fuel amount Tα during acceleration is set to a minimum value that allows a predetermined acceleration performance to be obtained.

In S15, the increase correction coefficient K is retrieved from the RAM under the same conditions as the rate of change Δα and the detected cooling water temperature. As shown in FIG. 7, this increase correction coefficient is stored in the RAM in a rewritable manner for each region partitioned by the rate of change Δα and the cooling water temperature. The initial value of the increase correction coefficient for each area is set to 1.

In S16, the threshold width of the interrupt pulse signal (in other words, the actual increased fuel amount during acceleration) is calculated by multiplying the retrieved increased fuel amount Tα during acceleration by the increase correction coefficient.

In S17, an interrupt pulse signal is outputted to the fuel injection valve 10 between the drive pulse signals to perform interrupt injection and increase the amount of fuel for acceleration.

Next, the learning routine for the increase correction coefficient will be explained according to the flowchart shown in FIG.

Acceleration G detected in 321 when it is determined that it is an acceleration operation.

, various signals such as cooling water temperature are read in, and at 522, the timer starts counting.

In S23, a change ΔG in the detected acceleration G7 is calculated. Specifically, as shown in FIG. 8, the detected accelerations G, , G, . . . , G, are sampled at predetermined intervals. Then, the change in acceleration between the previous time and this time ΔG (=G
z G+).

In S24, it is determined whether the time t counted by the timer is within the set time T, and if YES, the process advances to S25 and N
If o, the process returns to S21. Here, the set time T is set from the time when the acceleration operation is determined until immediately after the increased amount of fuel during acceleration due to the interrupt injection is combusted.

In S25, it is determined whether or not the calculated acceleration change ΔG exceeds zero. If YES, it is determined that the vehicle is being accelerated by the interrupt injection, and the process returns to 521. In addition, when the change in acceleration ΔG is less than zero even though interrupt injection has been performed, for example, as shown in FIG. 8, when the acceleration decreases and the vehicle is decelerated, the increase searched in the flowchart of FIG. 4 in S26 0.05 is added to the correction coefficient K, and ゛ is calculated as a new increase correction coefficient.

Then, in S27, the increase correction coefficient K is stored in the RAM under the same conditions as the rate of change Δα of the intake throttle valve opening and the cooling water temperature.
is updated to the new increase correction coefficient.

Therefore, during the next acceleration operation, a new increase correction coefficient larger than the previous increase correction coefficient is used, and the increase amount of fuel during acceleration Tα is used to calculate the actual increase in fuel during acceleration! (Tα×°)
is determined, so the actual increased fuel amount during acceleration increases from the previous time. Therefore, even if fuel injection characteristics deteriorate due to, for example, manufacturing variations in fuel injection valves, a decrease in the air-fuel ratio can be prevented. As a result, deterioration of combustibility or misfire during acceleration can be prevented, and proper acceleration performance can be obtained by increasing acceleration as shown by the broken line in FIG. 8 during interrupt injection.

Here, the increase correction coefficient K is corrected within a predetermined range so that the increased fuel amount Tα during acceleration falls within the region surrounded by the chain line in FIG. 6, thereby setting the target acceleration so that the actual acceleration does not decrease.

FIG. 9 shows an embodiment of the second invention. Incidentally, the same elements as in FIG. 2 are given the same reference numerals and their explanations will be omitted.

In the figure, the engine 21 includes first to fourth pressure sensors 22a to 2 as pressure detection means for detecting the combustion pressure of each cylinder.
2d are provided, and detection signals from these pressure sensors 22a to 22d are inputted to a control device 23' via an amplifier 3. The control device 23 also includes a crank angle sensor 2.
4, the crank angle signal (rotational speed signal) is manually input. Furthermore, an intake air flow rate signal, an intake throttle valve opening signal, and a cooling water temperature signal are inputted to the control device 23 via the A/D converter 4, as in the previous embodiment.

Here, the control device 23 serves both as calculation means and correction means.

Next, the operation will be explained according to the flowchart shown in FIG. 1O. Incidentally, the fuel injection amount control routine is the same as the third one in the above embodiment.
Since it is similar to the flowchart in FIG. 4 and FIG. 4, the explanation will be omitted and only the learning routine will be explained.

When an acceleration operation is determined, various signals such as the detected combustion pressure P and cooling water temperature are read in 331, and a timer starts counting in 332. Here, the combustion pressure P is determined by the crank angle signal of the crank angle sensor 24, for example.
Read every ″.

In S33, the indicated mean effective pressure p is determined from the detected combustion pressure P.
, is determined for each cylinder. Specifically, P is the total volume per hit, and dV is the stroke volume change.

In S34, it is determined whether the time t counted by the timer is within the set time T, and if YES, the process advances to S25 and NO.
In this case, the process returns to S21. Here, the set time T is set from the time when the acceleration operation is determined to the time immediately after the fuel increased during acceleration due to the interrupt injection is combusted, as in the embodiment described above.

In S35, the previous indicated mean effective pressure P in the same cylinder,
It is determined whether or not the pressure difference between the indicated mean effective pressure Pm and I during the stroke following that stroke exceeds zero, and if YES, it is determined that the vehicle is being accelerated by the interrupt injection. S31 Return to

In addition, when the pressure difference is less than zero despite the interrupt injection, that is, the indicated average is the dynamic pressure Pm.

is lower than the indicated average effective Pi and the vehicle is decelerated due to deterioration of combustion performance or occurrence of misfire, the fourth
The increase correction coefficient K found in the flowchart in the figure is 0.
05 is added and ' is calculated as a new increase correction coefficient.

Then, in S37, the increase correction coefficient K is stored in the RAM under the same conditions as the rate of change Δα of the intake throttle valve opening and the cooling water temperature.
is updated to the new increase correction coefficient.

Therefore, in the same way as in the embodiment described above, during the next acceleration operation, the actual amount of increased fuel during acceleration (Tα×°) is determined by a new increase correction coefficient that is larger than the previous increase correction coefficient. As a result, the actual increased fuel amount during acceleration increases from the previous time, so the same effect as in the embodiment described above is achieved.

Here, as in the embodiment described above, the increase correction coefficient K is corrected within a predetermined range so that the indicated mean effective pressure P becomes the target indicated mean effective pressure.

In each of the examples, the acceleration operation was determined from the rate of change in the opening of the intake throttle valve, but the rate of change in the intake negative pressure.

The acceleration operation may be determined from the rate of change in the intake air flow rate, the rate of change in the basic injection amount, or the like. Further, although the increase correction coefficient is rewritten, the increase fuel amount during acceleration may be rewritten.

<Effects of the Invention> As explained above, the present invention corrects and rewrites the increased fuel amount during acceleration in the storage means according to the acceleration state of the vehicle or the indicated average effective pressure of the combustion pressure. During acceleration, deterioration of combustion performance or misfire can be prevented, and appropriate acceleration performance can be obtained.

[Brief explanation of drawings]

Fig. 1 is a diagram corresponding to the claims of the first and second inventions, Fig. 2 is a configuration diagram showing an embodiment of the first invention, Figs. 3 to 5 are flowcharts of the same as above, and Figs. 6 to 8. 9 is a block diagram showing an embodiment of the second invention, FIG. 10 is a flowchart of the same, and FIG. 11 is a diagram for explaining the drawbacks of the conventional method. . 1... Vehicle 2... Acceleration sensor 5, 23.
...Control device 9...Intake throttle valve opening sensor 10
...Fuel injection valve 11...Drive circuit 22a~
22d...Pressure sensor patent applicant Japan Electronics Co., Ltd. Agent Patent attorney Fujio SasashimaFigure 1He-JFigure 3Figure 4Figure 5Figure 6Figure 7Figure 10Figure 11

Claims (2)

[Claims] (1) A fuel injection amount setting means that sets the fuel injection amount during steady operation based on the operating state of the engine, and a drive pulse signal corresponding to the set fuel injection amount to the fuel injection valve in synchronization with the engine rotation. A drive pulse output means for outputting, a storage means for storing an increased fuel amount during acceleration set corresponding to the acceleration operation amount, an acceleration detection means for detecting the acceleration operation amount, and an acceleration operation amount for detecting the acceleration operation amount according to the detected acceleration operation amount. a retrieval means for retrieving an increased amount of fuel during acceleration from the storage means; and an interrupt pulse signal corresponding to the retrieved increased amount of fuel during acceleration inserted between the drive pulse signals at an early stage of acceleration to the fuel injection valve. an interrupt pulse output means for outputting an interrupt pulse; a vehicle acceleration state detection means for detecting an actual acceleration state of the vehicle; and a vehicle acceleration state detection means for detecting an actual acceleration state of the vehicle; 1. An acceleration increase control device for a fuel injection internal combustion engine for a vehicle, comprising a correction means for correcting the amount of fuel to be increased during acceleration, and an update means for rewriting data in the storage means to the corrected increase fuel amount during acceleration. (2) A fuel injection amount setting means that sets the fuel injection amount during steady operation based on the operating state of the engine, and a drive pulse signal corresponding to the set fuel injection amount to the fuel injection valve in synchronization with the engine rotation. A drive pulse output means for outputting, a storage means for storing an increased fuel amount during acceleration set corresponding to the acceleration operation amount, an acceleration detection means for detecting the acceleration operation amount, and an acceleration operation amount for detecting the acceleration operation amount according to the detected acceleration operation amount. a retrieval means for retrieving an increased amount of fuel during acceleration from the storage means; and an interrupt pulse signal corresponding to the retrieved increased amount of fuel during acceleration inserted between the drive pulse signals at an early stage of acceleration to the fuel injection valve. an interrupt pulse output means for outputting, a pressure detection means for detecting the combustion chamber pressure of the engine, a calculation means for calculating the indicated mean effective pressure per stroke at the initial stage of acceleration based on the detected combustion pressure; A correction means for correcting the increased fuel amount during acceleration so that the indicated average effective pressure becomes the target indicated average effective pressure, and an updating means for rewriting the data in the storage means to the corrected increased fuel amount during acceleration. An acceleration increase control device for a vehicle fuel-injected internal combustion engine, characterized in that: