JP2512789B2 - Engine fuel control device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to vehicle engine control, and more particularly to an engine control device suitable for fuel control during acceleration / deceleration.

[Conventional technology]

A conventional air-fuel ratio control device, for example, as described in JP-A-60-219428, interrupt injection that is not synchronized with the rotation of the engine at the time when acceleration is detected as compensation for a sudden increase in air amount during acceleration. The amount of fuel increase is injected by a preset amount according to the state of acceleration.

[Problems to be solved by the invention]

In the prior art, the acceleration fuel supply amount is predetermined. For this reason, it was not possible to correct this even if it deviated from the optimum value due to variations in manufacturing and changes with time after manufacturing. Therefore, it was not possible to sufficiently meet the demands of the driver.

Specifically, for example, a smooth acceleration characteristic cannot be obtained, or the torque generation is less than the acceleration characteristic requested by the driver, or the torque is too high.
There was a problem that the characteristics of the engine deviated from the characteristics required by the driver.

An object of the present invention is to provide an engine control device that produces optimum acceleration characteristics.

[Means for solving problems]

In order to achieve the above object, in the present invention, the fuel supply amount determined based on the engine operation information is supplied in synchronization with the rotation of the engine, and the acceleration fuel is supplied asynchronously with the rotation of the engine by detecting the acceleration operation state. In the supply, an air-fuel ratio sensor that gives an output proportional to the oxygen concentration of the exhaust gas of the engine, driver instruction means that gives a driver's instruction regarding the driving of the vehicle, a map and an acceleration table for determining the acceleration fuel supply amount are provided. The map includes a basic map that holds the basic injection time t0 corresponding to the basic acceleration fuel amount as a function of the initial throttle opening θTH during acceleration and the change rate ΔθTH of the throttle opening, and the air-fuel ratio sensor. To correct the basic injection time by the time when the air-fuel ratio detected by exceeds the specified reference air-fuel ratio It consists of a correction map that holds the correction injection time t1 as a function of the throttle opening θTH and the rate of change ΔθTH of the throttle opening.The acceleration table uses the degree of acceleration as a parameter to determine the acceleration characteristics indicated by the driver. An acceleration characteristic table given as a correction coefficient of 1 and an economic efficiency instruction table giving a characteristic of economic efficiency instructed by the driver as a second correction coefficient with the engine speed as a parameter are included. It is characterized in that it is determined based on the time obtained by multiplying the sum of the basic injection time t0 and the corrected injection time t1 by both of the above correction coefficients.

[Action]

In the present invention, the excess or deficiency of the acceleration fuel supply amount can be detected from the state of the exhaust gas, whereby the acceleration data that determines the acceleration fuel amount can be corrected and the acceleration fuel supply amount can be made appropriate.

In the present invention, depending on the driver's intention, for example, the acceleration characteristics can be changed depending on whether a rapid torque generation is desired at the time of acceleration or a smooth torque generation is desired.
The control characteristics according to the driver's request can be obtained.

〔Example〕

 Examples will be described below with reference to the drawings.

FIG. 2 is a partial cross-sectional view schematically showing the entire control system of the engine. Intake air passes through the air cleaner 2, the slot torque chamber 4, and the intake pipe 6 and is supplied into the cylinder 8. The gas fueled in the cylinder 8 is discharged into the atmosphere through the exhaust pipe 10.

The throttle 4 is provided with an injector 12 for injecting fuel, and the fuel injected from the injector 12 is atomized in the air passage of the throttle 4 and mixed with intake air. A mixture is formed, and this mixture is supplied to the combustion chamber of the cylinder 8 through the intake pipe 6 and the opening of the intake valve 20.

A throttle valve 14 is provided near the outlet of the injector 12. The throttle valve 14 is configured to be mechanically interlocked with the accelerator pedal and is driven by the driver. The injector 12 may be provided upstream of the throttle valve 14. Also throttle valve 14
May be electrically opened according to the operation amount of the accelerator pedal.

An air passage is provided upstream of the throttle valve 14 in the throttle slot 4.
22 is provided, and an air amount sensor 24 including a thermal air flow meter including an electric heating element is disposed in the air passage 22 and outputs an electric signal AF that changes according to the air flow velocity.
Since the sensor 24 composed of this heating element (hot wire) is provided in the bypass air passage 22, it is protected from high temperature gas generated at the time of backfire from the cylinder 8 and is contaminated by dust in intake air. It is also protected from things. The outlet of the bypass air passage 22 is opened near the narrowest part of the bench lily, and the inlet is opened on the upstream side of the bench lily.

The fuel, which is pressurized from the fuel tank 30 through the fuel pump 32, is constantly supplied to the injector 12, and when the injection signal from the control circuit 60 is given to the injector 12, the injector 12 is connected to the inside of the intake pipe 6. Is injected with fuel.

The air-fuel mixture sucked from the intake valve 20 is compressed by the piston 50 and burned by the spark of the spark plug (not shown), and this combustion is converted into kinetic energy. The cylinder 8 is cooled by the cooling water 54. The temperature of the cooling water is measured by the water temperature sensor 56, and this measured value TW is used as the engine temperature.

The air-fuel ratio A / F (Air
An air-fuel ratio sensor 142 (A / F sensor) that outputs an analog voltage based on Fuel Ratio) is attached.

A crankshaft (not shown) outputs a reference angle signal for each reference crank angle, for example, 120 degrees for 6 cylinders, 180 degrees for 4 cylinders, and a position signal according to the engine speed. An angle sensor is provided.

The output of the crank angle sensor, the output signal TW of the water temperature sensor 56, the output signal of the A / F sensor 142, and the electric signal AF from the sensor 24 enter the control circuit 60 including a microcomputer, a memory, etc., and the injector 12 and the ignition device. It becomes the input to control 62.

Further, the throttle 26 is provided with a bypass 26 that bypasses the throttle valve 14, and the bypass 26 is provided with a bypass valve 61 that is controlled to open and close.

This bypass valve 61 is provided in the bypass 26 provided by bypassing the throttle valve 14, and is controlled to open / close by a pulse current, and changes the cross-sectional area of the bypass 26 by its lift amount. The output of the circuit 60 drives and controls the drive unit. That is, the control circuit 60 generates an opening / closing cycle signal for controlling the drive section, and the drive section adjusts the lift amount of the bypass valve 61 by the opening / closing cycle signal.

Therefore, in FIG. 2, the injector 12 is controlled to perform air-fuel ratio (A / F) control and fuel increase / decrease control, and the engine speed control (ISC) during idling by the bypass valve 61 and the injector 12 is performed. It can be performed.

FIG. 3 is a diagram showing the overall configuration of a control circuit 60 using a microcomputer and a diagram showing connections between sensors and actuators around the control circuit 60. A central processing unit (hereinafter referred to as CPU) and a read only memory are shown. (Hereinafter referred to as ROM), a random access memory (hereinafter referred to as RAM), and an input / output circuit 108. The CPU 102 calculates the input data from the input / output circuit 108 by various programs stored in the ROM 104, and returns the calculation result to the input / output circuit 108 again. The RAM 106 is used for intermediate storage required for these calculations. CPU1
Various kinds of data are exchanged between the 02, ROM 104, RAM 106, and the input / output circuit 108 by a bus line 110 composed of a data bus, a control bus, and an address bus.

The input / output circuit 108 includes a first analog-digital converter 122 (hereinafter referred to as ADC1) and a second analog-digital converter 122.
It has input means of a digital converter 124 (hereinafter referred to as ADC2), an angle signal processing circuit 126, and a discrete input / output circuit 128 (hereinafter referred to as DIO) for inputting / outputting one bit information.

The outputs of the battery voltage detection sensor 132 (hereinafter referred to as VBS) and the air-fuel ratio sensor 142 (hereinafter referred to as A / FS) are added to the ADC1 to the multiplexer 162 (hereinafter referred to as MPX), One of these is selected by the MPX162 and input to the analog / digital / conversion circuit 164 (hereinafter referred to as ADC). The digital value output from the ADC 164 is stored in register 166.
(Hereinafter referred to as REG).

From the angle sensor 146 (hereinafter referred to as ANGLS), a signal indicating a reference crank angle (for example, 180 ° crank angle (in the case of four cylinders) (referred to as REF)) and a signal indicating a minute angle (for example, 1 degree crank angle) ( (Hereinafter referred to as POS)) is output,
The signal is added to the angle signal processing circuit 126, where the waveform is shaped.

The DIO 128 includes an idle switch 148 (hereinafter referred to as IDLE-SW) and a top gear switch 150 (hereinafter referred to as TOP-SW) that operate when the throttle valve 14 is returned to the fully closed position. Starter switch (hereinafter referred to as START-SW) is input.

Next, a pulse output circuit and a control target based on a calculation result of the CPU will be described. An injector control circuit 1134 (hereinafter referred to as INJC) is a circuit that converts a digital value of a calculation result into a pulse output. Therefore, a pulse INJ having a pulse width corresponding to the fuel injection amount is generated by the INJC 1134 and applied to the injector 12 via the AND gate 1136.

The ignition pulse generation circuit 1138 (hereinafter referred to as IGNC) includes a register (hereinafter referred to as ADV) for setting the ignition timing and a register (hereinafter referred to as DWL) for setting the primary current conduction start time of the ignition coil. And these data are set by the CPU. This pulse IGN is generated via an AND gate 1140 to an amplifier 62 for generating a pulse IGN based on the set data and supplying a primary current to the ignition coil.
Add.

The opening rate of the bypass valve 61 is controlled by a pulse ISC applied from a control circuit (hereinafter referred to as ISCC) 1142 via an AND gate 1144. ISCC1142 has a register ISCD for setting the pulse width and a register ISCP for setting the pulse period.

The 1-bit input / output signal is controlled by the circuit DIO128. Input signals include IDLE-SW signal, START-SW signal, and TOP-SW signal. Further, as the output signal, there is a pulse output signal for driving the fuel pump. This DIO
Is provided with a register DDR192 for deciding whether to use a terminal as an input terminal and a register DOUT194 for latching output data.

The mode register 1160 is a register (hereinafter, referred to as MOD) that holds an instruction to instruct various states inside the input / output circuit 108. For example, by setting an instruction set in the mode register 1160, AND gates 1136, 1140, 1144. , 1156 are all in operating state or inactive state.
By setting an instruction in the MOD register 1160 in this way, it is possible to control the stop and start of the output of INJC, IGNC, and ISCC.

Signal to control the fuel pump 32 to DIO128
DIO1 is output.

In the control system shown in FIG. 2 and FIG. 3, the fuel injection by the injector 12 is intermittently performed periodically in synchronization with the rotation of the engine, and the fuel injection amount is controlled in one injection operation. This is performed by controlling the valve opening time of the injector 12, that is, the fuel injection time T _i .

Therefore, in the embodiment of the present invention, this T _i is set as follows.

T _i = K _ref · T _p · (1 + β) · COEF + T _s (1) T _p = k · Q _a / N… (2) K _ref = 1 / λ where k: coefficient Q determined by the injector _a : intake air amount N: engine speed T _p : basic fuel injection time β: control amount COEF: sum of various correction factors T _s : battery voltage correction time K _ref : set air-fuel ratio coefficient λ: excess air coefficient The basic fuel injection time T _p is calculated from the air amount Q _a and the engine speed N by the equation (2), and is multiplied by the set air-fuel ratio coefficient K _ref to obtain the fuel injection time which is almost the target air-fuel ratio. Also, the fuel injection time to achieve the target air-fuel ratio by the feedback control amount β by the air-fuel ratio sensor
Let T _i . In the case of open loop control, β = 1.0.

Here, in the feed back control, proportional / integral / derivative operation is generally known, but in the feed back control of an automobile using an air-fuel ratio sensor, proportional / integral / derivative operation is also performed.
Precise air-fuel ratio control is performed by the differential operation (PID control).
Therefore, the calculation of the manipulated variable β using the microcomputer is preferably performed at every rotation cycle of the engine in consideration of the dead time of the engine, the time constant, and the sampling cycle. This manipulated variable β can be expressed by the following equation.

_{β = K p · e n +} ΣK i · e n + K d · (e n -e n-1) ... (3) (A / F) i: the air-fuel ratio of the i th point (A / F) _OB: target Air-fuel ratio where K _{p is} proportional gain K _{i is} integral gain K _{d is} differential gain e _{i is} deviation (e _i = (A / F) _i − (A / F) _OB ) Fig. 4 shows fuel during acceleration Shows injection and air-fuel ratio change. By depressing the accelerator pedal in the steady running state, the throttle valve opens and the vehicle enters the acceleration state. θTH is the throttle valve opening. In the fuel injection, the steady injection amount that is normally synchronized with the position signal (b) is calculated according to the equation (1), and the fuel is injected. Here, in the case of acceleration, interrupt injection is performed. Since the control of the fuel system is delayed with respect to the air flow rate, the interrupt injection that is asynchronous with respect to the steady injection is performed. If the interrupt injection is not performed during acceleration, a lean spike of the air-fuel ratio occurs as shown in FIG. 4 (d), and a torque drop during acceleration occurs as shown in FIG. 4 (f). On the other hand, when the interrupt injection is performed, the lean spike can be eliminated as shown in FIG. 4 (e), and smooth generation of torque can be realized as shown in (g).

However, in the conventional air-fuel ratio control, as shown in FIG. 5, for example, about four stages of fuel supply amount, for example, interrupt injection time is set with respect to the time point change rate of the throttle valve. Since it was fixed, it was not possible to respond to changes over time and changes in operating conditions. Therefore, in the present invention, an air-fuel ratio deviation (for example, a lean spike as shown in FIG. 4D) reflecting the interrupt injection immediately after acceleration is detected, and the acceleration state (Δθ _TH / Δt in FIG. 4A) is detected. ) Is updated and stored as a learning value, and when the same acceleration state occurs next time, the learning value is used to correct the interrupt injection amount to optimize the injection amount.

FIG. 1 is a block diagram showing one embodiment of the present invention.
When acceleration is detected by the acceleration detection means 2000, the fuel supply amount corresponding to the acceleration state is searched from the acceleration table 3500, interrupt injection is performed by the interrupt injection means 3600, and the air-fuel ratio deviation thereafter is detected by the air-fuel ratio deviation detection means 1000. The data of the acceleration table is detected, the data of the acceleration table is calculated by the acceleration table learning means, and this value is written in the acceleration table 3500. Here, the acceleration state detecting means 2000 is means for calculating an angular change Δθ _TH of the slot angle detected by the slot sensor θ _TH 140 within a fixed time, and determining acceleration when a certain value or more. The CPU 102 takes in the slot angle, calculates the rate of change of the opening, and determines acceleration. In addition to this, acceleration detection can also be judged by a change in intake air amount or a change in accelerator pedal operation amount. When the acceleration state is detected, the interrupt injection means 3600 is driven to execute the interrupt injection. On the other hand, the air-fuel ratio deviation immediately after this acceleration is detected by the air-fuel ratio deviation detecting means 1000, and the acceleration table learning means 3000 updates the acceleration table 3500. The air-fuel ratio deviation detection means 1000 detects the output of the air-fuel ratio sensor 24, and the CPU 102
The target air-fuel ratio written in advance and determined by the engine speed N and the basic injection time T _P is read out, and the deviation of the air-fuel ratio input from the air-fuel ratio sensor from the target air-fuel ratio is calculated. The above calculation is executed according to the program stored in the ROM 104 via the CPU. The acceleration table learning means 3000 writes the acceleration injection amount or the acceleration injection correction amount in the acceleration table 3500 as necessary with the acceleration state from the acceleration state detection means 2000 and the air-fuel ratio deviation from the air-fuel ratio deviation detection means 1000 as input values. . The above procedure is performed via the CPU 102, and its control program is stored in the ROM 104. This acceleration table has a format having a correction value or a fuel amount, which is data for each divided acceleration state, and these values are stored in the RAM 106. It may be stored in a non-volatile memory instead of the RAM. Interrupt injection means 36
00, when acceleration is detected by the acceleration state detection means 2000, interrupts the CPU 102 to interrupt the program in progress, saves it, and then searches the acceleration table for a correction value, which is acceleration data according to the acceleration state. In addition to the interrupt injection amount according to the acceleration state, the asynchronous fuel injection amount that is the interrupt injection amount at the relevant time is calculated, and the calculation result is set in the indication register 1136, and the injector 12 is activated and interrupted. Acceleration injection, which is injection, is executed. The above procedure is also executed according to the program stored in the ROM 104 via the CPU 102.

FIG. 6 is a flow chart showing the above procedure. FIG. 7 is a detailed flow chart of FIG. Acceleration detection 2010 is a tester (program management unit) executed at regular time intervals, for example, every 10 ms, and the difference between the slot angle detected the last time (10 ms ago) and the angle detected this time is taken to obtain Δθ _{TH in} step 2022. Ask for. Alternatively, the maximum angle change within a certain period of time may be captured. Further, instead of the throttle angle, the intake air amount or the accelerator pedal depression amount may be changed. The Δθ _TH obtained by the above procedure is compared with a predetermined comparison value Δθ _THS, and if it exceeds the predetermined value, it is determined that the vehicle is in an accelerated state, and interrupt injection 3610 is performed. At this time, the eighth
The basic interrupt injection time t ₀ as shown in the figure is indexed from a map (in this case 8 × 8) having a function as a function of the initial throttle angle θ _TH and the rate of change Δθ _TH at the time of acceleration, and is created in advance. Acceleration table (interruption injection correction map t _l (Δθ _TH , θ _TH ), the acceleration fuel supply amount (interruption injection time T _to
Is calculated in step 3611.

After the interrupt injection, it is determined in step 2013 that the interrupt injection has been performed, and the interrupt injection correction learning 3010 is executed. First step
At 3011, the air-fuel ratio deviation is detected. This takes the maximum value of the air-fuel ratio deviation from two rotations to eight rotations after the interrupt injection. This is because the fuel for interrupt injection is detected after two revolutions because it takes four strokes (four-cycle engine) until it is sucked and discharged, and the air-fuel ratio deviation thereafter is monitored for a certain period of time to find the maximum value during that period. Eight revolutions is a value that should be changed depending on the engine characteristics. Further, the air-fuel ratio deviation x is a constant K _lo at step 3012.
It is multiplied and becomes the evaluation value K _l , which is a constant criterion (here 0.1)
If larger, learn to learn in step 3013
Move to 3014. Further, if K _l is an extremely large value, in step 3014 it is considered that a sensor or other abnormality is the cause and learning is terminated.

Learning, as shown in step 3015, t _l (Δθ _TH , θ _TH ) = t _l (Δθ _TH , θ _TH ) _OLD + K _l …
(4) The value previously stored in the map is updated. However, this value is the upper limit value or the lower limit value (here -5.0 to +
If it exceeds 5.0), the upper and lower limits are set in steps 3016, 3017, 3018, 3019. The above is the interrupt injection correction learning 3010.

 FIG. 9 is a model showing the effect of learning.

Drawings (a-1)-(a-3) show the state before learning.
As shown in (a-3), the output of the air-fuel ratio sensor 142 has a value proportional to the oxygen concentration of the exhaust gas of the engine. Since the learning t _e is “0”, the basic interrupt injection amount t ₀
Only. The size at that time is now the basic unit of 1.0. At this time, the interrupt injection amount becomes insufficient, a lean spike occurs, and acceleration table learning (interruption injection correction learning) is performed to set the map coefficient to 0.30. Figures (b-1) to (b
-3) indicates the time when the same acceleration occurs next time, and the learning value is added to this interrupt injection, and T _t0 becomes 1.30. Although the lean spike is reduced by this, in the figures (c-1) to (c-3) in which further learning is performed and the next similar acceleration occurs, the lean spike becomes smaller than the predetermined value, and it corresponds to the acceleration.
We can get T _t0 of 1.45.

According to one embodiment of the present invention, in the interrupt injection correction learning, the air-fuel ratio deviation test and the learning value test are performed, and the safe interrupt injection (complete with the fail-safe mechanism when the sensor is abnormal or malfunctioning) It has the effect of realizing accelerated fuel supply).

In the above embodiment, the interrupt injection amounts t ₀ and t _l are θ
_The map relating to _TH and θ _TH is a two-dimensional map, but each dimension can be selected in the range of 1 to n.

FIG. 10 is a flow chart showing another embodiment of the present invention. The start 4000 of this flow chart is the start of the routine for steady injection. At the time of interrupt injection for acceleration, the interrupt injection embodiment flag is set at step 2000 or step 3610 in FIG. After that, the number of engine revolutions is counted, and then the following two blocks are processed until M revolutions are reached. First is the steady-state injection; correction is performed after the interrupt injection of formula (1), and T _i ′ = T _i + K _ts · t _l (Δθ _TH , θ _TH ) ... (5) Formula (1) Modify T _i in the second term. This is more As described above, the correction may be reduced according to the rotation m after the interrupt injection. These steady-state injection corrections mean the disturbance of the air-fuel ratio and the correction of the fuel supply amount due to the execution of interrupt injection.
The sign of _ts can be selected according to engine characteristics, both positive and negative. The magnitude of the coefficient t _{e of} step 4020 is determined with the acceleration degree Δθ _TH and the throttle opening θ _TH as parameters. Further, the coefficient T _ts is lowered as shown in FIG. 11 based on the passage of time or the integrated value of the engine speed. Therefore, the fuel supply amount is increased by K _ts · t _e from the calculation result T _i of the fuel supply amount in the steady state, and decreases with the lapse of time. Further, in addition to the learning control of the acceleration interrupt injection, there is a case where the steady learning in which the correction of the fuel supply amount during the steady running is learned from the parameters of the air-fuel ratio closed loop control is performed, but even if this control condition is satisfied, the step 4010 is performed. Under the condition of 1, the steady learning control is not performed because it is the state after acceleration. For this reason, the stationary learning is prohibited in step 4030.

According to the present embodiment, there is an effect that the air-fuel ratio fluctuation after the interrupt injection is reflected in the steady injection as well, and the air-fuel ratio fluctuation can be further reduced, and the steady learning in the unstable region of the air-fuel ratio fluctuation after the interrupt injection is prohibited. By doing so, it is possible to avoid uncertain learning.

According to the above-described embodiment, since the interrupt injection amount can be optimized by learning, on-board autotuning of the interrupt injection amount becomes possible. Here, the basic injection time t ₀ and the correction map t _l may be combined into one and all interrupt injection amounts may be determined by t _l .

According to this embodiment, there is an effect that the interrupt injection amount can be optimized even if the capacity of the RAM used is reduced.

Next, another alternative is shown. Acceleration characteristics should be changed according to the driver's intention and driving environment. The driver's intention is input from the instruction means 136 shown in FIG. For example, a variable resistor is used. Fig. 12 is a principle diagram, in which the driver gives hope by the lever. Multiplexer 16 so that the instruction content is input to ADC164 as voltage
Input to 2.

The embodiment is shown in FIG. 13, and as in FIG.
In 2010, determine whether the vehicle is in an accelerated state. Step 3614
To read the desired acceleration characteristics. Fig. 14 is the table, and the characteristics of I to E are determined by the driver's instruction, and the data is selected according to the degree of acceleration. Incidentally, this characteristic is stored as data as a tail with a driver instruction and a degree of acceleration Δθ _TH as a parameter. This table lookup of step 3614 is performed. In step 3616, the driver instruction for economy is fetched and the economy data table is searched. This table uses the economy instruction and the engine speed N as parameters. Its characteristics are shown in FIG. When the driver desires high acceleration in the acceleration data tad table shown in FIG. 14, characteristic (i) is selected, and when quietness is desired, characteristic (e) is selected, and characteristic (e) is selected from characteristic (i) by voltage for the lever position. Fig. 15 shows the table of economic data ted. When high output is desired, a is selected, while when economic is selected, characteristic e is selected.

Step 3618 is obtained by adding steps 3611, tad and ted shown in FIG. As a result, the acceleration fuel supply amount is determined, and acceleration injection is performed in step 3612.

When the driver's instruction is fetched in steps 3614 and 3616, the driver instruction mode is entered and learning control is not performed.

As another embodiment, control based on the driving environment will be shown. It is detected whether the driving environment is a high speed dolo, a normal road or a parking lot by the navigation 90 in Fig. 3 or the driver's instruction. Figure 16 shows the correction coefficient K _a depending on the driving environment.
FIG. If it is a highway, the a characteristic is selected. On the other hand, in the parking lot, the C characteristic is selected, and when traveling in the city, the B characteristic is selected. The correction coefficient K _a based on this environmental condition is selected in step 3620 of FIG. 13, and the value obtained by multiplying the fuel injection amount T _t0 by this coefficient K _a is set as the new fuel injection amount in step 3622, and this value is output. Register (INJC113 in Fig. 3
4) Set, and asynchronous acceleration injection is performed.

Also, steps 3624 and 3626 limit the maximum fuel supply during acceleration based on the driver's economic desires. The output shown in Fig. 12 detects the demand for economy and determines the maximum required fuel quantity. Supplying a fuel of more than this value will waste the fuel economically, so it is limited to less than this value. Therefore, the acceleration characteristic is slightly lowered, but the fuel ratio is greatly improved.

〔The invention's effect〕

According to the present invention, it is possible to provide an engine with good maneuverability, in which fluctuations in the air-fuel ratio during acceleration are suppressed even when aging or driving conditions change, and torque is constantly low.

Further, in the present invention, it is possible to control the acceleration characteristics according to the driver's intention.

[Brief description of drawings]

Fig. 1 is a basic block diagram for correcting the amount of accelerated fuel supply based on the state of exhaust gas, Fig. 2 is an overall system diagram, Fig. 3 is a hardware block diagram, and Fig. 4 is accelerated fuel injection. FIG. 5 is a table showing the basic fuel amount for accelerated injection, FIG. 6 is an explanatory diagram for the operation of accelerated fuel injection,
FIG. 7 is a detailed explanatory view of FIG. 6, FIG. 8 t ₀ map and t _e map, FIG. 9 is a motion explanatory view, FIG. 10 is a motion diagram of acceleration increase after acceleration correction, and FIG. 11 is a coefficient. FIG. 12 is a characteristic diagram of K _ts , FIG. 12 is a principle diagram of the driver indicating means, FIG. 13 is a flow chart showing another embodiment, and FIGS. 14, 15, and 16 are characteristics of coefficients tad, ted, Ka. It is a figure. 24 …… Air-fuel ratio sensor, 12 …… Injector, 102 …… CP
U, 106 ... RAM, 140 ... Slottle angle sensor, 2000 ...
… Acceleration state detection means, 1000 …… Air-fuel ratio deviation detection means, 30
00 ... correction map learning means, 3500 ... interrupt injection correction map, 36000 ... interrupt injection means.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-63-41635 (JP, A) JP-A-62-261629 (JP, A) JP-A 61-25938 (JP, A) JP-A 53- 20019 (JP, A)

Claims (2)

(57) [Claims] Claim: What is claimed is: 1. A fuel supply amount, which is determined on the basis of engine operating information, is supplied in synchronism with the rotation of the engine, and acceleration fuel is supplied asynchronously with the rotation of the engine by detecting an accelerating operation state. An air-fuel ratio sensor that gives an output proportional to the oxygen concentration of the exhaust gas, driver instruction means that gives a driver's instruction regarding the driving of the car, a map and an acceleration table for determining the acceleration fuel supply amount, Basic injection time corresponding to the acceleration fuel amount
A basic map that holds t0 as a function of the initial throttle opening θTH during acceleration and the change rate ΔθTH of the throttle opening, and the air-fuel ratio detected by the air-fuel ratio sensor exceeds a predetermined reference air-fuel ratio. The corrected injection time t1 for correcting the basic injection time according to the time
It consists of a correction map that is held as a function of TH and the change rate ΔθTH of the throttle opening, and the acceleration table has the degree of acceleration as a parameter.
The acceleration characteristic table which gives the acceleration characteristic instructed by the driver as the first correction coefficient, and the economical characteristic which the driver instructed with the engine speed as the parameter
Economic efficiency instruction table given as a correction coefficient of the acceleration fuel supply amount, and the acceleration fuel supply amount is determined based on the time obtained by multiplying the sum of the basic injection time t0 and the correction injection time t1 by both the correction coefficients. Characteristic engine fuel control device. 2. A fuel for an engine according to claim 1, which has operating environment data, and determines the acceleration fuel supply amount based on the data of the acceleration table and the operating environment data. Control device.