JPS61234242A - Fuel supply device for internal-combustion engine - Google Patents

Abstract

PURPOSE:To enable an engine to be smoothly accelerated and decelerated even when a characteristic of the internal-combustion engine is changed due to its aged deterioration of the like, by correcting the damping rate of an acceleration and deceleration correction coefficient to be study controlled on the basis of an output signal from an O2 sensor. CONSTITUTION:A microprocessor 21, obtaining the opening of a throttle valve 32 in every predetermined time on the basis of a detection result in an opening sensor 33, decides speed change required time of an internal-combustion engine 26 by a change rate of said throttle valve opening, and the microprocessor, after it performs an acceleration and deceleration correction, returns its coefficient to 1.0 by a predetermined damping rate. In this way, after the microprocessor decides the engine is the acceleration or deceleration required time, the microprocessor, correcting on the basis of an output signal from an O2 sensor 35 the damping rate of the acceleration and deceleration correction coefficient in the present use to be addition or subtraction controlled so that a time of air-fuel ratio changing from a rich condition to a lean condition or from the lean condition to the rich condition becomes a predetermined value, stores the damping rate in a RAM 23 as a new damping rate.

Description

[Detailed Description of the Invention] [Summary] When increasing or decreasing the rotation speed of an internal combustion engine, conventionally, the fuel injection amount is adjusted based on the acceleration/deceleration correction amount and the attenuation rate (fixed value) stored in the storage means. However, the present invention is configured to perform learning control on the attenuation rate, thereby enabling smooth acceleration and deceleration even when the characteristics of the internal combustion engine change due to aging or the like.

[Industrial application field]

The present invention relates to an improvement in a fuel supply system for an internal combustion engine, and more particularly, to a fuel supply system for an internal combustion engine that can smoothly perform acceleration and deceleration even when the characteristics of the internal combustion engine change due to aging or the like. It is related to.

[Conventional technology]

Based on the detection results of an O2 sensor such as a zirconia 02 sensor that detects the oxygen concentration in the exhaust gas of an internal combustion engine, it is determined whether the air-fuel ratio A/F is in a rich state or a low state. It has been proposed in the past to perform air-fuel ratio feedback control based on the air-fuel ratio.

Figure 8 is a diagram showing the relationship between the state of the air-fuel ratio A/F and the air-fuel ratio correction coefficient FAF.The air-fuel ratio correction coefficient FAF is calculated after skipping a certain amount when the air-fuel ratio A/F becomes rich. , decreases at a predetermined slope, and when the air-fuel ratio A/F becomes lean, increases at a predetermined slope after skipping a certain amount. Note that the reason why the air-fuel ratio correction coefficient FAF is skipped by a certain amount is to eliminate the influence of the response delay of the 02 sensor. Incidentally, the fuel injection amount TAU is determined by multiplying the basic injection 11TP determined by the rotation speed of the internal combustion engine and the intake air amount by the air-fuel ratio correction coefficient FAF, and the air-fuel ratio correction coefficient FAF is determined by the air-fuel ratio correction coefficient FAF. /F decreases when it is in a rich state and increases when it is in a rich state, so the basic injection amount TP is determined by multiplying the air-fuel ratio correction coefficient FAF to inject the amount of fuel. This makes it possible to bring the actual air-fuel ratio closer to the stoichiometric air-fuel ratio.

By performing air-fuel ratio feedback control like this, the actual air-fuel ratio can be brought close to the stoichiometric air-fuel ratio in steady state, but when the throttle valve opening is suddenly changed for acceleration or deceleration. In this case, the air-fuel ratio becomes far different from the stoichiometric air-fuel ratio, and there is a problem in that smooth acceleration and deceleration cannot be performed. Now, for example, Figure 9 (A)
Assume that the opening of the throttle valve is suddenly increased at time t1 for acceleration, and the opening of the throttle valve is suddenly decreased for deceleration at time t2, as shown in FIG.
The output signal of the 02 sensor, which outputs a signal corresponding to the oxygen concentration in the exhaust gas, is at a low level for a while after acceleration, and at a high level for a while after deceleration, as shown in FIG. 2(B). In other words, when the opening of the throttle valve is suddenly increased for acceleration, a state of excess air and insufficient fuel (lean state) occurs, and when the opening of the throttle valve is suddenly decreased for deceleration, there is a temporary state of excess air and insufficient fuel (lean state). In a state of excess fuel and insufficient air (
rich condition), which adversely affects drivability and smooth acceleration.

There was a problem that deceleration could not be performed.

Therefore, in order to solve this problem, the fuel i TAU to be supplied to the internal combustion engine is determined by the following equation (1), and the acceleration/deceleration correction coefficient α is changed as shown in FIG. 9(C). It is also proposed that However, in the opening ceremony, TP is the basic injection amount determined from the rotational speed of the internal combustion engine and the amount of intake air, and FAF is the air-fuel ratio correction coefficient.

TAU = TPx FAP x ct ------
---(1) Here, as can be seen from the same figure (C), the acceleration/deceleration correction coefficient α is held at 1.0 in the non-acceleration/deceleration state,
During an acceleration request, the unit correction amount increases by Δα, and during a deceleration request, the unit correction amount decreases by Δα. Therefore, fuel shortage during acceleration or excess fuel during deceleration is prevented, and acceleration and deceleration are performed smoothly. becomes possible. Furthermore, when the acceleration request and deceleration request are completed, the acceleration/deceleration correction coefficient α returns to 1.0 at predetermined damping rates β and β'. In addition, the same figure (D
) shows the output signal of the 02 sensor when the amount of fuel determined by equation (1) is supplied to the internal combustion engine.

However, the conventional example described above also has the following problems.

That is, in the past, the damping rates β and β were set to fixed values, so if the characteristics of the internal combustion engine change due to aging etc.
Alternatively, if the damping rates β and β′ are not appropriate for the internal combustion engine, there is a problem that emissions and drivability are adversely affected.

[Problems to be Solved by the Invention] The present invention solves the above-mentioned problems, and its purpose is to accelerate or decelerate even when the characteristics of the internal combustion engine deteriorate due to aging etc. The goal is to make sure that things can be done smoothly.

[Means for solving problems]

In order to solve the above-mentioned problems, the present invention includes an 02 sensor 2 that outputs a signal corresponding to the oxygen concentration in the exhaust gas of an internal combustion engine 1, and a a first correction coefficient calculating means 3 for calculating an air-fuel ratio correction coefficient based on an output signal of the first correction coefficient calculating means 3, a determining means 4 for determining whether or not it is time to request a change in the rotational speed of the internal combustion engine l; The second correction coefficient calculation means 6 calculates the acceleration/deceleration correction coefficient based on the determination result and the acceleration/deceleration correction amount and attenuation rate stored in the storage means 5, and the first correction coefficient calculation means 3 calculate the acceleration/deceleration correction coefficient. an injection amount calculation means 7 for calculating a fuel injection amount to the internal combustion engine 1 based on the air-fuel ratio correction coefficient calculated by the second correction coefficient calculation means 6, an acceleration/deceleration correction coefficient calculated by the second correction coefficient calculation means 6, and a basic injection amount; an injection means 8 for supplying the engine 1 with an amount of fuel corresponding to the calculation result of the injection amount calculation means 7;
In the internal combustion engine fuel supply system comprising: the storage means based on the output signal of the 02 sensor 2 after the determination means 4 determines that it is time to request a change in the rotational speed of the internal combustion engine 1; Attenuation rate changing means 9 for changing the attenuation rate stored in 5 is provided.

[For production]

Even if the characteristics of the internal combustion engine change due to aging or the like, acceleration and deceleration can be performed smoothly.

〔Example〕

FIG. 2 is a block diagram of an embodiment of the present invention, in which 21 is a microprocessor, 22 is a ROM in which control programs etc. for causing the microprocessor 21 to perform predetermined operations are stored, and 23 is an acceleration/deceleration correction A RAM having a bank-up power supply in which coefficient α, unit correction amount Δα, attenuation rate β, β′, etc. are stored; 24 is an input section; 2 is an output section; 26 is an internal combustion engine main body; 27 is an air cleaner; 28 is an air flow meter , 29 is a throttle chamber, 30 is an intake manifold, 31 is a fuel injector, 32 is a throttle valve, 33 is an opening sensor that detects the opening of the throttle valve 32, 34 is a water temperature sensor that detects the cooling water temperature,
35 is a 02 sensor that outputs a signal corresponding to the oxygen concentration in exhaust gas, 36.37 is a 〇 converter, and 38 is a crank that outputs a position detection signal every time the crankshaft (not shown) rotates by a certain angle. It is an angle sensor.

Further, FIGS. 3 to 6 are flowcharts showing part of the processing contents of the microprocessor 21, and the operation of FIG. 2 will be explained below with reference to the same figures.

The microprocessor 21 performs the processing shown in the flowchart of FIG. 3 at predetermined time intervals during its processing flow. That is, the microprocessor 21 calculates the opening degree θn of the throttle valve 32 based on the detection result of the opening degree sensor 33 that detects the opening degree of the throttle valve 32 at predetermined time intervals (step S1), and then degree θn and the opening degree θ obtained in step Sl of the previous cycle. -l difference Δθ=θ. -θn-/ is determined (step S2), and then it is determined whether the difference Δθ satisfies Δθ>0 (step S3). If the determination result in step S3 is YES, the absolute value 1Δθ1 of the difference Δθ is 1Δθ1.
Step S to judge whether θlax is satisfied or not.
4), and if the judgment result in step S3 is NO, 1Δ
It is determined whether θ1 satisfies the relationship 1Δθl>y (step S7).

That is, in step S4, it is determined whether the rate of change in the opening degree of the throttle valve 32 in the direction in which the throttle valve 32 is opened (hereinafter referred to as the rate of change in the downward direction) is greater than or equal to a predetermined value, and in step S7, it is determined whether or not the rate of change in the opening degree of the throttle valve 32 in the direction in which the throttle valve 32 is opened is greater than or equal to a predetermined value. This means that it is determined whether the rate of change in the direction of closing (hereinafter referred to as the rate of change in one direction) is greater than or equal to a predetermined value.

If the determination result in step S4 is YES, that is, if it is determined that it is required to increase the rotational speed of the internal combustion engine 26, the microprocessor 21 stores the RAM 2
The unit correction amount Δα is added to the acceleration/deceleration correction coefficient α stored in 3.
The added value is set as a new acceleration/deceleration correction coefficient α in RAM2.
3 (step S5), and then moves to another control step S6. Also, the determination result in step S7 is YES.
In this case, the microprocessor 21 stores in the RAM 23 the value obtained by subtracting the unit correction amount Δα from the acceleration/deceleration correction coefficient α stored in the RAM 23 as a new acceleration/deceleration correction coefficient α (step S8). Control step S6
Move to.

Therefore, as shown in FIG. 7(A), if the throttle valve 32 is suddenly opened for acceleration at time t1, the determination result in step S4 becomes YES, and the step of increasing the acceleration/deceleration correction coefficient α Since the process of S5 is performed, the acceleration/deceleration correction coefficient α gradually increases while there is an acceleration request, as shown in FIG. Also, the same figure (
As shown in A), if the opening of the throttle valve 32 is suddenly closed for deceleration at time t7, the determination result in step S7 is YES, and the process in step S8 is to reduce the acceleration/deceleration correction coefficient α. As a result, the acceleration/deceleration correction coefficient α gradually decreases as shown in FIG.

The microprocessor 21 also performs the processes shown in the flowcharts of FIGS. 4 and 5 at predetermined time intervals.

That is, the microprocessor 21 determines the opening θ of the throttle valve 32 based on the detection result of the opening sensor 33 at predetermined intervals.
Find n (step 511), then find the difference Δθ=θn-θn≠ between the opening degree θn found in step 311 and the opening degree θn−/ found in step Sll of the previous cycle (step 512), and then calculate the difference It is determined whether Δθ satisfies the relationship Δθ>0 (step 513). If the determination result in step S13 is YES, 1 & (step 313a), which rOJc the flag FA',
The microprocessor 21 calculates the absolute value 1Δθ1 of the difference Δθ.
It is determined whether or not satisfies the relationship 1Δθl>H (step 514), and if the determination result in step S13 is NO, the flag FA is set to "0" (step 513b).
), it is determined whether lΔθ1 satisfies the relationship 1ΔθI>y (step 526).

Then, if the judgment result in step S14 is NO, the flag FA is set to "0" (step 525), and then the process of step 33B is performed, and if the judgment result is YES, the flag FA is "1" or not. (Step 51)
5). Then, if the judgment result in step 315 is YES, the processing in step 338 is performed, and if the judgment result is NO, the flag FA is set to "1" (step 516), and then the counter A provided internally in software is
, B's karantoi direct CNTA.

Set CNTB to "0" and step S L7.18)
, then set the flag FB to "0" (step 519),
Next, the flag FC is set to "1" (Step 520), the flag FD is set to "0" (Step 521), and the AD converter determines whether or not the air-fuel ratio at that time is Lynch-like Mu. The determination is made based on the output signal of the 02 sensor 35 applied via the 02 sensor (step 522). Then, if the determination result in step S22 is YES, after setting the flag FB to "1" (step 523), step 3
38 processing, and if the judgment result is NO, flag F
After setting E to "0" (step 524), step 83
8.

Here, the flag FA is set to "1" in step 516 when the rate of change in the opening degree of the throttle valve 32 in the + direction is equal to or greater than the predetermined value If the rate of change in the opening degree in the child direction is less than or equal to the predetermined value It will only be done once. Also, step S1
At 7,1B, the count values CNTA, CNTB
The counters A and B whose values are set to "0" are set to "0" for a predetermined period of time (for example, 1
Interrupt routine that occurs every 0 m5ec (Figure 6)
It is something that is advanced by.

Further, if the determination result in step 326 is NO, the microprocessor 21 sets the flag FA' to "0".
L (step 537) and step 338 are performed, and if the determination result is YES, it is determined whether the flag F^° is "1" (step 527). If the determination result in step S27 is YES, the microprocessor 21 performs the process in step 33B, and if the determination result is NO, the microprocessor 21 sets the flag FA' to "1" and performs step S33B.
28), then count values CNTA of counters A and B
, Set CNTB to "0" and step 829, 30)
, then set the flag FB to "0" (step 531),
Next, the flag FC is set to "0" in step 532), then the flag FD is set to "1" in step 533), and then 02 is added via the AD converter group and the input section 24.
Based on the sensor output signal, it is determined whether the air-fuel ratio at that time is in a lean state (step 534). Then, if the determination result in step 334 is YES, after setting the flag FE to "1" (step 536), step 3
38 processing, and if the judgment result is NO, flag F
After setting E to "0" (step 535), step 33
Perform process B.

Here, the flag FA' is set to "1" in step 328 when the rate of change in the opening degree of the throttle valve 32 in one direction is equal to or greater than a predetermined value of 7 (when the determination result in step S26 is YES), and the flag FA' is set to "1" in step 328. If the rate of change in the opening degree of 32 in one direction is less than or equal to the predetermined value y (if the determination result in step S26 is NO), it is set to "0" in step S37, so the processing in steps 328 to S36 is performed. is performed only once at the start of deceleration. Also, step 3
The functions of flag FB to flag FB initialized at 19-21.23.24°31-33.35.36 are as follows. The flag FB becomes "1" when the air-fuel ratio first changes from a lean state to a rich state after detecting an acceleration request, or when the air-fuel ratio first changes from a rich state to a lean state after detecting a deceleration request. set, flag FC
is set to "1" when an acceleration request is detected, flag FD
is set to "1" when a deceleration request is detected, and the flag PE is set to "1" when the air-fuel ratio at the start of the acceleration request is in a rich state or when the air-fuel ratio at the start of the deceleration request is in a lean state. It is something.

Further, in step 538 (FIG. 5), the microprocessor 21 determines whether the flag FC is "1" or not.
If the determination result is NO, the process of step S55 is performed, and if the determination result is YES, it is determined whether the flag PH is "1" (step 539). For example, if the output signal of the 02 sensor 35 changes as shown in FIG.
0", the judgment result in step S39 is NO. Also, if the output signal of the O2 sensor changes as shown in FIG.
is set to "1" in the Step S edict, so
The determination result in step S39 is YES.

If the determination result in step S39 is YES, that is, the air-fuel ratio at the start of the acceleration request (time tl) is as shown in FIG. 7(D).
If the air-fuel ratio is in the rich state as shown in step 547), the microprocessor 21 determines whether the air-fuel ratio at that time is in the lean state based on the output signal of the 02 sensor 35 (step 547), and the determination result is N.

In this case, the process moves to another control step S72, and the determination result is Y.
In the case of ES, after setting the flag FB to "0" (step 5
4B), the measurement time TA by counter A is TA<0, 1
It is determined whether 5 seconds is satisfied (step 549). That is, in step 549, when the acceleration request starts (
This means that it is determined whether the time from time t1 to time t2 when the air-fuel ratio becomes lean is within 0.15 seconds.

Then, if the determination result in step S49 is Y, the microprocessor 21 moves to another control step 372,
If the judgment result is No, after setting the flag FC to “0” (
Step 542), the measurement time TB by counter B is T
It is determined whether the relationship B<0.3 sec is satisfied (step 543). If the determination result in step SO is YES, the microprocessor 21 determines that the attenuation rate β is too large, and subtracts the predetermined value Δβ from the attenuation rate β stored in the RAM 23, which is the value β−Δβ. After storing it in the RAM 23 as the attenuation rate β (step 546), the process moves to another control step S72, and
If the determination result in step S43 is NO, it is determined whether the time TB measured by counter B (time from time t1 to t2) is TB<2.5 sec (step 544), and if the determination result is YES. If the judgment result is NO, the process moves to another control step S72, and if the judgment result is NO, the damping rate β
is determined to be too small, and the value β+Δβ, which is obtained by adding a predetermined value Δβ to the attenuation rate β stored in the RAM 23, is stored in the RAM 23 as a new attenuation rate β (step 545);
After this, the process moves to another control step S72.

That is, if the air-fuel ratio at the start of the acceleration request (time tl) is in a rich state as shown in FIG. If the time is 0.15 sec or more and 0.3 sec or less, the attenuation rate β will decrease by the predetermined value Δβ (
Step 546), if the time from time t1 to time t2 is 2.5 seconds or more, the attenuation rate β is increased by a predetermined value Δβ (step 545).

Further, if the determination result in step S39 is NO, that is, if the air-fuel ratio at the start of the acceleration request t1 is in a lean state as shown in FIG. 7(C), or if the flag PH is set to "0" in step S4B. If it is set to , flag FB
It is determined whether or not is "0" (step 540).

Here, since the flag FB has been set to "0" in step S19, the determination result in step S40 is YES at the acceleration request start time t1. If the determination result in step 540 is YES, the microprocessor 21 determines whether the air-fuel ratio at that time is in a rich state based on the output signal of the O2 sensor 35 (step 550). If the judgment result in step S50 is NO, the process moves to another control step S72, and if the judgment result is YES, the count value CNTB of counter B is
is set as rOJ (step 551), then the flag FB is set to "1" (step 552), and then it is determined whether the time TA measured by the counter A satisfies the relationship TA≧1 sec (step 553).

That is, by performing the process of step S51, if the air-fuel ratio at the acceleration request start time t1 is in a lean state as shown in FIG. 7(C), the time t3 at which the air-fuel ratio changes from a lean state to a rich state At this time, the count value CNTB of counter B is set to rOJ, and the air-fuel ratio at t1 at the start of the acceleration request is in a rich state as shown in the figure (D>), and from time t1 to time t2. If the time of If the air-fuel ratio at the start of the request t1 is in a lean state as shown in FIG. Request start time t1
The air-fuel ratio is in a rich state as shown in the same figure (D),
And the time from time tl to time t2 is 0.15 seconds
If it is within 1 sec, it is determined whether the time from time tl to time t4 is 1 sec or more.

If the judgment result in step S53 is No, the microprocessor 21 moves to another control step S72, and if the judgment result is YES, after setting the flag PC to "0" (step 554), the microprocessor 21 moves to another control step S72. The process moves to S72.

If the determination result in step 540 is NO, the microprocessor 21 determines whether the air-fuel ratio at that time is in a lean state based on the output signal of the 02 sensor 35 (step S 41 ). Then, if the judgment result in step S41 is NO, the microprocessor 21 moves to another control step S72, and if the judgment result is YES, it sets the flag FC to "0" (step 542), and then sets the measurement time TB by the counter B. determines whether or not satisfies the relationship TB<0.3sec (step 543
). Here, since the flag FB is set to "1" in step 352, in step S43, if the air-fuel ratio at the start of the acceleration request t1 is in a lean state as shown in FIG. 7(C), The time from time t3 to time t5 is 0
．． 3 seconds or less, and the air-fuel ratio at the start of the acceleration request t1 is in a rich state as shown in FIG. If it is within 15 seconds, it is determined whether the time from time t4 to time t6 is within 0.3 seconds. If the determination result in step 343 is YES, the microprocessor 21 determines that the attenuation rate β is too large, and subtracts the predetermined value Δβ from the attenuation rate β stored in the RAM 23, which is the value β−Δβ. Store it in the RAM 23 as the attenuation rate β (status 7"54
6) If the determination result is No, it is determined whether the time TB measured by the counter B satisfies the relationship TB<2.5 sec (step 544).

If the determination result in step 344 is YES, it is determined that the currently used attenuation rate β is appropriate, and the attenuation rate β is not rewritten and another control step S7 is performed.
2, if it is determined that the attenuation rate β is too small, the value β+Δβ is calculated by adding a predetermined value Δβ to the attenuation rate β stored in the RAM 23.
After storing it in the RAM 23 as a new attenuation rate β (step 545), the process moves to another control step 372.

Further, if the judgment result in step 338 is NO, the microprocessor 21 judges whether the flag FD is "1" (step 555), and if the judgment result is No, the microprocessor 21 moves to another control step S72. , the judgment result is YES
In this case, determine whether the flag FE is "1" (
step 856). For example, if the output signal of the 02 sensor 35 changes as shown in FIG. 7(C), the flag FB was set to "0" in step S35, so the determination result in step S56 is NO , and if the output signal of the 02 sensor 35 changes as shown in FIG.
”, the determination result in step S56 is YES.

If the determination result in step S56 is YES, that is, the air-fuel ratio at the start of the deceleration request (time t7) is as shown in FIG. 7(D).
If the condition is lean as shown in step 564), the microprocessor 21 determines whether the air-fuel ratio at that time is in the rich condition based on the output signal of the 02 sensor 35 (step 564), and if the determination result is NO moves to another control step S72, and if the judgment result is YES, the flag FE is
After setting 0 to 0 (step 565), it is determined whether the time TA measured by counter A satisfies TA<0.15 sec (step 566). That is, in step 366, from the start of the deceleration request (time t7) to time t8
The time it takes for the air-fuel ratio to reach a rich state is 0.1.
This means that it is determined whether or not it is within 5 seconds.

Then, if the determination result in step S66 is YES,
The microprocessor 21 moves to another control step S72, and if the determination result is NO, sets the flag FD to "0" (step 559), and then sets the measurement time TB by the counter B.
It is determined whether or not the relationship TB<0.3 sec is satisfied (step 560). And step S
If the determination result in step 60 is YES, the microprocessor 21 determines that the attenuation rate β' is too large and subtracts the predetermined value Δβ' from the attenuation rate β° stored in the RAM 23, which is the value β'-Δβ'. After storing the new attenuation rate β in the RAM 23 (step 563), another control step S
72, it is determined whether TB<2.5 sec (step 561), and the result of the determination is YES.
In this case, the process moves to another control step S72, and the judgment result is N.
In the case of O, it is judged that the attenuation rate β is too small, and RAM2
The RAM 23 stores the value β+Δβ1, which is obtained by adding a predetermined value Δβ′ to the attenuation rate β” stored in
(step 562), and then the process moves to another control step S72.

That is, if the air-fuel ratio at the start of the deceleration request (time t7) is in a lean state as shown in FIG. If the time is within 0.3 sec, the attenuation rate β' will be reduced by the predetermined value Δβ' (step 563).
, if the time from time t7 to time t8 is 2.5 seconds or more, the attenuation rate β' increases by a predetermined value Δβ' (step 562).

Further, if the determination result in step S56 is NO, that is, if the air-fuel ratio at the time t7 when the deceleration request starts is in a rich state as shown in FIG. 7(C), or if the flag FE is set to rOJ in step S65. If so, flag FB
It is determined whether or not is rOJ (step 557).

Here, since the flag FB has been set to "0" in step S31, the determination result in step 357 is YES at time t7 when the deceleration request starts. If the determination result in step S57 is YES, the microprocessor 21 determines whether the air-fuel ratio at that time is in a lean state based on the output signal of the 02 sensor 35 (step 567), and in step S67 If the judgment result is NO, the process moves to another control step S72, and if the judgment result is "tBS", the count value CNT of counter B is
B is set to "0" (step 868), and then the flag FB is set to "0".
is set as rlJ (step 369), and then it is determined whether the time T^ measured by the counter A satisfies the relationship T^≧1 sec (step 570).

That is, by performing the process of step 368, if the air-fuel ratio at t7 when the deceleration request starts is in a rich state as shown in FIG. 7(C), the air-fuel ratio changes from a rich state to a low state. At time t9, the count value CNTB of counter B is set to "0", and the air-fuel ratio at t7 when the deceleration request starts is in a lean state as shown in FIG. If the time from t7 to time t8 is within 0.15 seconds, the count value CNTB of counter B will be set to "0" at time tlo when the air-fuel ratio changes from the rich state to the lean state.

Further, in step S70, if the air-fuel ratio at the time t7 when the deceleration request starts is in a rich state as shown in FIG.
This means that it is determined whether the time from time t7 to time t9 is 1 sec or more, and when the deceleration request starts at t.
7 is in a lean state as shown in the figure (D), and the time from time t7 to time t8 is 0.15 se.
If it is within c, it is determined whether the time from time t7 to time tlO is 1 sec or more.

If the judgment result in step S70 is NO, the microprocessor 21 moves to another control step S72, and if the judgment result is YES, after setting the flag FD to "0" (step 371), the microprocessor 21 moves to another control step S72. The process moves to S72.

If the determination result in step S57 is NO, the microprocessor 21 determines whether the air-fuel ratio at that time is in a rich state based on the output signal of the 02 sensor 35 (step 858). Then, if the judgment result in step 55B is NO, the microprocessor z1 moves to another control step 372, and if the judgment result is YES, it sets the flag FD to "0" (step 559), and then sets the measurement time TB by the counter B. It is determined whether or not the relationship TB<0.3 sec is satisfied (step 560).

Here, since the flag FB is set to "1" in step 569, in step 560, if the air-fuel ratio at t7 at the start of the deceleration request is in a rich state as shown in FIG. 7(C), The time from time t9 to time tll is 0.
3 seconds or less, and if the deceleration is within 0.15 seconds, the time 11
This means that it is determined whether the time from 0 to time t12 is within 0.3 seconds. And step S6
If the judgment result of 0 is YES, microprocessor 2
1 determines that the attenuation rate β' is too large, and stores the value β'-Δβ' obtained by subtracting the predetermined value Δβ' from the attenuation rate β' stored in the RAM 23 as a new attenuation rate β' in the RAM 23 ( Step 563), if the judgment result is NO, the measurement time TB by counter B is TB<2.5 sec.
Determine whether the relationship is satisfied (Step 5)
61).

If the determination result in step S61 is YES, that is, the time from time t9 to time tll or time tlO
If it is determined that the time from The process moves to S72, and the determination result in step S61 is N.
In the case of O, that is, if it is determined that the time from time t9 to time tll or from time 110 to 112 is 2.5 seconds or more, the attenuation rate β' is determined to be too small and is stored in the RAM 23. After the value β'+Δβ', which is obtained by adding a predetermined value Δβ' to the existing attenuation rate β°, is stored in the RAM 23 as a new attenuation rate β' (step 562), the process moves to another control step 372.

Here, the processing in steps Sll to 72 will be explained with reference to FIG. 7 as follows. That is, at the start of the acceleration request t
If the air-fuel ratio of 1 is in a lean state as shown in FIG. 553). Then, from time t1 to time t3
If it is determined that the time to
O), if the time from time t1 to time t3 is less than 1 sec,
It is determined whether the time from time t3 to time t5 satisfies ■↑B<0.3 sec ■TB≧2.5 sec ■0.3 sec≦TB<2.5 sec (step 343. 44)
. If it is determined that the condition (■) is satisfied, the currently used attenuation rate β is considered too large and the predetermined value Δβ is subtracted from the attenuation rate β stored in the RAM 23, and the value is set as the new attenuation rate β. It is stored in the RAM 23 (step 546), and if it is determined that (2) is satisfied, it is determined that the currently used attenuation rate β is too small, and the RAM 23 is stored.
The value obtained by adding a predetermined value Δβ to the attenuation rate β stored in 23 is stored in the RAM 23 as a new attenuation rate β (step 345). Assuming that the rate β is appropriate, the attenuation rate β is not rewritten.

In addition, if the air-fuel ratio at the start of the acceleration request t1 is in a rich state as shown in FIG.
It is determined whether the time from time t1 to time t2 is within 0.15 seconds (step 549).
If it is determined that the time until the end of the process is 0.15 seconds or more, it is determined whether the time satisfies the above conditions (■, ■, or ■), and the same processing as described above is performed based on the determination result. It is something.

Also, the time from time t1 to time t2 is 0.15 se.
If it is determined that it is within c, from time t1 to time t4
Determine whether the time until
step 553). If it is determined that the time from time t1 to time t4 is 1 sec or more, the attenuation rate β is not rewritten, and if the time from time t1 to time t4 is less than 1 sec, from time t4 to time t6
It is determined whether the time until the end satisfies the conditions (1), (2), or (2) described above, and the same processing as described above is performed based on the determination result.

Further, if the air-fuel ratio at the time t7 when the deceleration request starts is in a rich state as shown in FIG. 7(C), from time t7 to time t
It is determined whether the time up to 9 is 1 sec or more (step S70). Then, from time t7 to time t9
If it is determined that the time until the end is l sec or more, the attenuation rate β' is not rewritten (the flag FD is set to "0" in step S71, so that the determination result in step S55 becomes NO). ), time t7
If the time from time t9 to time t9 is less than 1 sec, the time from time t9 to time tll is
,■ is satisfied (Step 3)
60.61). If it is determined that the condition (■) is satisfied, the currently used attenuation rate β'' is too large and the predetermined value Δβ'' is subtracted from the attenuation rate β' stored in the RAM 23 to create a new attenuation. RAM2 as rate β′
3 (step 563), and if it is determined that (2) is satisfied, it is determined that the currently used attenuation rate β'' is too small, and the attenuation rate β'' stored in the RAM 23 is set to a predetermined value Δβ. ' is stored in the RAM 23 as a new attenuation rate β' (step 562), and if it is determined that (2) is satisfied, the currently used attenuation rate β' is deemed to be appropriate and the attenuation rate β is changed. ° is not rewritten.

In addition, if the air-fuel ratio at the time t7 when the deceleration request starts is in a lean state as shown in FIG.
It is determined whether the time until the end of the process is within 0.15 seconds (step 866). Then, from time t7 to time t8
If it is determined that the time until the end of the process is 0.15 seconds or more, it is determined whether the time satisfies the above conditions (■, ■, or ■), and the same processing as described above is performed based on the determination result. It is something.

Also, the time from time t7 to time t8 is 0.15 se.
If it is determined that the mountain is higher than c, the time tl changes from time t7.
.

Determine whether the time until
Step S70). Then, from time t7 to time tlO
If it is determined that the time to
If the time until the end is less than 1 sec, the time tl.

It is determined whether the time from t12 to time t12 satisfies the above conditions (1), (2), or (2), and the same processing as described above is performed based on the determination result.

The microprocessor 21 also operates for a predetermined period of time (for example, 10
The process shown in the flowchart of FIG. 6 is also performed every time (m5ec), and in step S80, the count value CNTA of the counter A is incremented by 1, and in step S81, the count value C
Determine whether NTA is "0" and proceed to step S82.
Then, the count value CNTA is decremented by 1. In addition, counter A can count from "0" to "¥FFJ,"
Further, if the count value is incremented by 1 when the count value is "¥PFJ", the count value is set to "0", and if the count value is -1 when the count value is "0", the count value is set to [¥FFJ]. Therefore, if the determination result in step S81 is YES, the count value CNTA of the counter A is held at ¥FFJ, and if the determination result in step S81 is NO, the count value CNTA of the counter A is
A will be given +1.

Next, the microprocessor 21 increments the count value CNTB of the counter B by +1 (step 583), then determines whether the count value CNTB is "0" (step 584), and if the determination result is YES, the microprocessor 21 increases the count value CNTB by +1. -1 step 585), the judgment result is NO.
In this case, the process of step S86 is performed.

Note that counter B also has the same function as counter A, so if the judgment result in step S84 is NO, the count value CNTB is incremented by 1, and if the judgment result is YES, the count value CNTB is increased to ¥FFJ. will be retained.

In step S86, the microprocessor 21 increments the count value CNTC of the counter C provided internally by software by 1, and then the count value CNTC becomes "
5'' (step 587). Therefore, if the flowchart shown in the figure is started every 10m5ec as described above, then 50m5ec
Once every c, the determination result in step S87 becomes YES. If the judgment result in step S87 is NO, the microprocessor 21 moves to another control step S93, and if the judgment result is YES, the count value CNTC is set to "0" (step 588), and then the acceleration/deceleration correction coefficient α is set to 1. It is determined whether it is .0 (step 589). If the judgment result is No, the acceleration/deceleration correction coefficient α is α>1.0.
Determine whether the relationship is satisfied (step S
90). If the judgment result is YES, the acceleration/deceleration correction coefficient α is decreased by the attenuation rate β stored in the RAM 23 (step 591), and if the judgment result is NO, the acceleration/deceleration correction coefficient α is stored in the RAM 23. (step 592), and moves to control step S93 for this retransmission. That is, by performing the processing of steps 391 and 92, the acceleration/deceleration correction coefficient α is calculated as shown in FIG.
As shown in B), the attenuation rates β and β′ decrease or increase until the value reaches 1.0.

Although not explained in the above embodiment, the processing shown in the flowcharts of FIGS. 4 and 5 is performed by the water temperature sensor 3.
This is carried out only when it is determined that the internal combustion engine is completely warmed up based on the detection result of 4 or the like. Further, in the embodiment described above, acceleration is performed based on the rate of change in the opening degree of the throttle valve 32.

Although the deceleration request is detected, the acceleration is based on the rate of change in the amount of intake air or the rate of change in intake pipe pressure.

Of course, a deceleration request may also be detected. In addition, although not explained in the above embodiment,
The microprocessor 21 uses the formula (1) using other routines.
The calculation shown in FIG. 1 is performed, and an amount of fuel corresponding to the calculation result is supplied from the fuel injector 31 to the internal combustion engine.

〔Effect of the invention〕

As explained above, the present invention includes an O2 sensor that outputs a signal corresponding to the oxygen concentration in exhaust gas of an internal combustion engine, and a first correction that calculates an air-fuel ratio correction coefficient based on the output signal of the O2 sensor. a coefficient calculating means, a determining means for determining whether or not it is time to request a change in the rotational speed of the internal combustion engine (in the embodiment, it consists of an opening sensor 33, a microprocessor 21, etc.), and a determination by the determining means. a second correction coefficient calculation means for calculating an acceleration/deceleration correction coefficient based on the result and the acceleration/deceleration correction amount and attenuation rate stored in a storage means such as the RAM 23; an injection amount calculation means for calculating a fuel injection amount to the internal combustion engine based on a fuel ratio correction coefficient, an acceleration/deceleration correction coefficient calculated by the second correction coefficient calculation means, and a basic injection amount; and an injection means for supplying the internal combustion engine with an amount of fuel corresponding to the calculation result, wherein the determination means determines that it is time to request a change in the rotational speed of the internal combustion engine. attenuation rate changing means for changing the attenuation rate stored in the storage means based on the subsequent output signal of the 02 sensor, the attenuation rate β.

Since it is configured to perform learning control on β', even if the characteristics of the internal combustion engine change due to aging etc.
It has the advantage of being able to perform smooth acceleration and deceleration.

[Brief explanation of drawings]

FIG. 1 is a block diagram of the present invention, FIG. 2 is a block diagram of an embodiment of the present invention, and FIGS. 3 to 6 are microprocessor 21.
A flowchart showing part of the processing contents, FIG.
8 is a diagram showing the relationship between the air-fuel ratio and the air-fuel ratio correction coefficient, and FIG. 9 is a diagram illustrating the acceleration/deceleration correction coefficient α. 1.26 is the internal combustion engine, 2.35 is the 02 sensor, 3 is the first
4 is a judgment means, 5 is a storage means, and 6 is a correction coefficient calculation means.
2 is a second correction coefficient calculating means, 7 is an injection amount calculating means, 8 is an injection means, 9 is an attenuation rate changing means, 21 is a microprocessor, 22 is a ROM, 23 is a RAM, 24 is an input section, and 1 is an output section. , 27 is an air cleaner, 27 is an air flow meter, 29 is a throttle chamber, 30 is an intake manifold, 31 is a fuel injector, 32 is a throttle valve, 33 is an opening sensor, 34 is a water temperature sensor, 36.
37 is an AD converter, and 38 is a crank angle sensor. Patent Applicant Fujitsu Ten Ltd. Representative Patent Attorney Gobe Tamamushi (one other person) Block diagram of the embodiment of the present invention Figure 2 Flowchart showing the processing details of Microbe 0 ton + f21 No. 6 Client Fuel Ratio and Air Fuel Ratio Edge surface showing the relationship with the correction coefficient! 8 Figure 9 Time chart for acceleration/deceleration

Claims (1)

[Scope of Claims] An O_2 sensor that outputs a signal corresponding to the oxygen concentration in exhaust gas of an internal combustion engine; and a first correction coefficient calculation means that calculates an air-fuel ratio correction coefficient based on the output signal of the O_2 sensor. , a determining means for determining whether or not it is time to request a change in the rotational speed of the internal combustion engine; and determining an acceleration/deceleration correction coefficient based on the determination result of the determining means and the acceleration/deceleration correction amount and attenuation rate stored in the storage means. based on the air-fuel ratio correction coefficient calculated by the first correction coefficient calculation means, the acceleration/deceleration correction coefficient calculated by the second correction coefficient calculation means, and the basic injection amount. an injection amount calculation means for calculating the amount of fuel to be injected into the internal combustion engine, and an injection means for supplying an amount of fuel corresponding to the calculation result of the injection amount calculation means to the internal combustion engine. In the apparatus, a damping rate for changing the damping rate stored in the storage means based on the output signal of the O_2 sensor after the judgment means judges that it is time to request a change in the rotational speed of the internal combustion engine. A fuel supply device for an internal combustion engine, characterized by comprising a changing means.