JPS6017236A - Fuel supply control method under deceleration of internal-combustion engine - Google Patents

Abstract

PURPOSE:To improve the acceleration performance by performing the incremental correction of fuel through incremental acceleration only during specific interval while reducing the incremental acceleration for every trigger signal pulse to be produced for every predetermined crank angle position. CONSTITUTION:A fuel injection valve 6 is provided between an engine 1 and a throttle valve 3 of a suction tube 2. An engine rotary angle position Ne sensor 11 will produce a pulse at the predetermined crank angle position. An electronic control unit ECU5 will perform incremental correction of fuel through incremental acceleration only over predetermined interval to set the incremental acceleration such that it will be reduced for every occurrence of trigger signal pulse. Consequently, shock is relieved during acceleration resulting in improvement of acceleration performance.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a fuel supply control method during acceleration of an internal combustion engine, and in particular, to a method for controlling fuel supply during acceleration of an internal combustion engine, and in particular to a method for controlling fuel supply during acceleration of an internal combustion engine. This invention relates to a fuel supply control method that improves performance.

(Prior Art) As a fuel supply control method for an internal combustion engine, a valve opening time of a fuel injection device of an engine is synchronized with the generation of a pulse of a predetermined crank angle position signal, for example, a top dead center (TDC) signal. Parameter values representing the amount of intake air, such as absolute pressure in the intake pipe, and specifications representing the operating state of the engine, such as engine speed, absolute pressure in the intake pipe, engine water temperature, throttle valve opening, and exhaust gas. The fuel injection amount is determined by electronically adding and/or multiplying constants and/or coefficients depending on the concentration (oxygen concentration), etc., and the mixture is supplied to the engine. A fuel supply control method is known in which the air-fuel ratio of the fuel is controlled.

Generally, when accelerating an engine, it is necessary to enrich the air-fuel mixture by increasing the pressure and amount of fuel supplied to the engine. Conventionally, when engine acceleration is detected, an acceleration increase correction variable TAOO is set according to the opening speed Δθ of the throttle valve from the table shown in FIG. The valve opening time TOUT' is set based on engine operating parameter values such as several 7%l.
The mixture was enriched by adding The solid line in Fig. 2(b) shows the time change of the valve opening time TOUT', which is set based on the engine operating parameter values of the intake pipe absolute pressure and the engine rotation speed Ne.
The broken line indicates the value obtained by adding the variable value TAOO to this valve opening time TOUT'.

In such a fuel supply control method during acceleration, first, suppose that the above-mentioned variable value 7'AOO is not added as shown in FIG. 2(b).
If fuel is supplied to the engine along the time change of the valve opening time TOUT' shown by the solid line, the time change of the displacement amount of the engine mount part and the engine speed Ne in this case are shown in Fig. 2 ( Indicated by solid lines in g) and (d). More specifically, the valve opening time ``o+rT,' is determined by the increase in the absolute pressure in the intake pipe due to the opening operation of the throttle valve (Fig. 2 (C)), and the value corresponding to the increase in the absolute pressure in the intake pipe. From the point in time when the valve opening time 7'OUT' starts to increase due to engine acceleration (time A in Figure 2), the torque increases as a result of increasing the amount of fuel to the engine, and the engine speed increases. Until the reciprocal 1/#g (Fig. 2 (d)) starts decreasing (at point B on the time axis), in the illustrated example, the F3TDC (top dead center) signal (Fig. 2 (α) ).This time delay is mainly due to the delay between fuel supply and explosion, the detection delay of the sensor used to detect the operating state of the engine, and the time delay between when the throttle valve is opened and when the throttle valve is opened. This is due to the time delay until the charging efficiency increases, i.e. until the actual amount of intake air supplied to the engine reaches the value required to generate a torque increase useful for engine acceleration.In particular, electronic fuel injection In an internal combustion engine equipped with a supply device, a chamber is provided in the intake pipe downstream of the throttle valve in order to suppress pressure fluctuations in the intake pipe and reduce fluctuations in intake air amount due to pressure fluctuations, and a chamber is provided in the intake pipe downstream of the throttle valve to increase the intake pipe passage volume. Because of this, the delay time from opening the throttle valve to increasing charging efficiency is long.For this reason, such an engine has a time delay corresponding to the time between points A and B mentioned above compared to a gas pump engine. become longer.

During the period from time A to time B, the actual amount of intake air supplied cannot be accurately detected, mainly due to the delay in the detection of the absolute pressure in the intake pipe by the intake U self-contained counter pressure sensor, and the required amount during this period Fuel cannot be supplied. As a result, optimal combustion of the air-fuel mixture within the cylinder cannot be achieved. Furthermore, during this period, an effective increase in torque cannot be obtained due to the low through-filling efficiency mentioned above. Immediately after point B, when the charging efficiency increases and the amount of intake air actually supplied to the engine reaches the value necessary to generate an increase in torque that is effective for accelerating the engine, a sudden increase in torque occurs. . As a result of this torque increase, the engine speed N# suddenly increases, but prior to this increase in engine speed, the engine itself is displaced at its mounting position in an attempt to rotate about the crankshaft. The engine is usually fixed to a mount on the vehicle body via an elastic member such as rubber, but the displacement of this engine suddenly increases after point B on the time axis, as shown by the curve in Figure 2 (g). This displacement becomes approximately stable after time C, and the engine speed N# also increases smoothly. The sudden displacement of the engine mount between point B and point C is more than can be absorbed by the cushioning effect of elastic members such as rubber, and the displacement of the engine mount at point C A shock corresponding to the amount of downward overshoot from the stable displacement position during acceleration (the size of the shaded area in Fig. 1 (g)) shown below is caused, and the driver is also given an unpleasant shock. become.

Next, during acceleration, the above-mentioned valve opening time 7'0TJT' is adjusted as shown in Fig. 2 (Fig.
When the correction is made as shown by the dotted line in h), the above-mentioned time delay is slightly reduced because the inappropriateness of the fuel supply amount mainly due to the delay in detecting the absolute pressure inside the intake pipe is corrected. However, as shown in Fig. 3, the correction values 7'A and OO are only a function of the throttle valve opening speed Δθ and do not take into account the time change in displacement of the engine mount, so the torque generation characteristics are This cannot be improved, and the shock caused by the displacement of the engine mount becomes even greater as shown by the dotted line in FIG. 2 (tj).

Furthermore, in acceleration operation from deceleration, the position of the engine mount part during deceleration is on the deceleration side than the neutral position, so the amount of displacement of the engine mount part at the beginning of acceleration operation is large compared to acceleration operation from cruising. It will also be a big shock. Furthermore, the p-shock becomes even larger due to the addition of a shock due to the presence of backlash in the gears of the drive system.

(Problems to be Solved by the Invention) The present invention has been made in view of the above-mentioned points, and the problem to be solved by the present invention is to detect the operating state in which the engine should be accelerated, and then wait until an increase in torque effective for acceleration occurs. An object of the present invention is to provide a fuel supply control method that improves acceleration performance by shortening the time delay and alleviating shock during acceleration.

(Problem (Means for Solving)) According to the present invention, an internal combustion engine having a throttle valve disposed in the middle of an intake passage is operated in synchronization with a trigger signal pulse generated at each predetermined crank angle position. In a fuel supply control method for injecting and supplying a required amount of fuel according to a state, an acceleration request signal from the engine in a low load operating state is detected, and the throttle valve is opened from the time when all of the acceleration request signals are detected. increases with movement,
Increasingly correcting the fuel amount according to the acceleration increase value only for a period until the amount of intake air actually supplied to the engine reaches a value necessary to generate an increase in torque effective to accelerate the engine; There is provided a fuel supply control method during acceleration of an internal combustion engine, characterized in that the fuel amount corrected in this way is supplied to the engine, and the acceleration increase value is set to decrease every time a pulse of the trigger signal is generated. Ru.

Embodiments Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 4 is an overall configuration diagram of a fuel supply control device to which the method of the present invention is applied. Reference numeral 1 indicates, for example, a four-cylinder internal combustion engine, and as shown in FIG. A mounting member 1b is formed integrally with the cylinder block 1α on the side wall. The engine 1 is mounted to the vehicle chassis side mount 50 via the mounting member 1b and the mount rubber 51 with bolts 52. In FIG. 5, only one part for attaching the engine to the chassis is shown, and the others are omitted. Mine intake pipe 2 to engine l
is connected to the intake pipe 2, and a throttle valve 3 is provided in the middle of the intake pipe 2. A throttle valve opening sensor 4 is connected to the throttle valve 3 and converts the opening of the throttle valve into an electrical signal and sends it to an electronic control unit (hereinafter referred to as rEcUJ) 5.

A fuel injection valve 6 is provided in the intake pipe 2 between the engine l and the throttle valve 34. This fuel injection valve 6 is connected to the intake pipe 2
Each injection valve is provided for each cylinder slightly upstream of an intake valve (not shown), and each injection valve is connected to a fuel pump (not shown) and electrically connected to the ECU 5.
The valve opening time of fuel injection is controlled by the signal from 3.

On the other hand, an absolute pressure sensor (7'BA sensor) 8 is provided immediately downstream of the throttle valve 3 via a pipe 7, and the absolute pressure signal converted into an electrical signal by the absolute pressure sensor 8 is transmitted to the ECU 3. supplied to

Further, a smoked intake air temperature sensor 9 is installed downstream of the intake air temperature sensor 9 to detect the intake air temperature and supply a corresponding electric signal to the EcUs.

A water temperature sensor 1° mounted on the main body of the engine 1 is composed of a thermistor or the like, detects the engine cooling water temperature, and supplies a corresponding temperature signal to the ECU 3.

The engine rotational angular position (Me) sensor 11 and the cylinder discrimination (c'yL) sensor 12 are installed around the camshaft or crankshaft (not shown) of the engine 1), and the engine rotational angular position sensor 11 receives the TDC signal. , the cylinder discrimination sensor 12 outputs one pulse each at a predetermined crank angle position of a specific cylinder at a predetermined crank angle position for every 180 degree rotation of the engine crankshaft.
Each of these pulse signals 1iEcU5 is supplied.

The three-way catalyst 14 is disposed in the exhaust pipe 13 of the engine 1, and purifies components such as HC, CO, and NOx in the exhaust gas. The Ot sensor 15 is inserted into the exhaust pipe 13 upstream of the three-way catalyst 14, detects the oxygen concentration in the exhaust gas, outputs a signal corresponding to the detected value, and supplies the signal to the ECU 3. The ECU 3 is supplied with a signal from an atmospheric pressure sensor 16 that detects atmospheric pressure.

The ECU 3 determines engine operating states such as a fuel cut (fuel cutoff) operating range, low engine rotation range, acceleration range, and deceleration range based on the various engine parameter signals described above, and also determines the TD according to the engine operating state.
Fuel injection time T during which the injection valve 6 should be opened in synchronization with the C signal
OUT is calculated based on the following equation.

7' OUT =7' * xA", +7' A O
Cj XA'! 10A''3 Music (IJ) Here, Ti is the standard value of the injection time of the fuel injection valve 6, and is determined according to the engine rotation speed Ne and the absolute pressure in the intake pipe 7'BA.

7'AOO is a correction variable during acceleration according to the present invention, and this correction variable 7'AOO is similar to 7'A in FIG. 2, which will be described later.
Determined by the OO determination subroutine.

Variables , , and 8 are used to determine the optimal starting characteristics, exhaust gas characteristics, fuel efficiency characteristics, acceleration characteristics, etc. according to the engine operating conditions based on the engine parameter signals from each of the above-mentioned sensors. It is calculated based on a predetermined calculation formula so that

The ECU 3 adjusts the fc fuel injection time TOU as described above.
A drive signal for opening the fuel injection valve 6 based on T is supplied to the fuel injection valve 6.

FIG. 6 is a block diagram showing the circuit configuration inside the ECU 3 shown in FIG. 4. After the output signal from the engine rotation angle position sensor 11 shown in FIG.
The TDC signal is supplied to the central processing unit (hereinafter referred to as CPU) 503 and is also supplied to the Me counter 502. The Me counter 502 measures the current TDC signal from the time the TDC signal is input from the engine rotation angle position sensor J1.
It measures the time interval until the DC signal is input, and its count Me is proportional to the reciprocal of the engine rotation speed Be.

The Me counter 502 uses this counted value Mef data bus 51
0 to cpUs 03.

The output signals from each sensor such as the throttle valve opening sensor 4, the intake pipe absolute pressure sensor 8, and the engine water temperature sensor 10 in FIG. Yoshi sequential A-
The signal is supplied to a D converter 506.

The CPU 503 further connects a read-only memory (hereinafter referred to as ROM) 507, a random access memory (hereinafter referred to as RAM) 508, and a drive circuit 5 via a data bus 510.
Connected to 09 and 9. The RAM 508 temporarily stores the calculation results in the CPU 503, and the ROM 507 stores the calculation results in the CPU 503.
Control program executed by U503, intake pipe absolute pressure and engineering? It stores a basic injection time Ti map of the fuel injection valve 60 to be read based on the engine rotational speed, a plurality of correction variable TAOO table groups to be described later, and the like.

CPU503 is ROM507VC memory saletail ff1
The fuel injection time TOUT f of the fuel injection valve 6 is calculated according to the aforementioned various engine parameter signals and injection time correction parameter signals according to the llm program, and these calculated values are supplied to the drive circuit 509 via the data bus 510. . The drive circuit 509 supplies the fuel injection valve 6 with a control signal to open the fuel injection valve 6 according to the calculated value.

FIG. 7 is a flowchart of the correction variable TAOO'ft determination control program, and this program is executed every time the TDC signal is generated.

In this program, first, the amount of change Δθn in the valve opening θth of the throttle valve 3 shown in FIG. 4 is calculated (step 1). This calculation is based on the difference Δ between the valve opening θthn detected at the current TDC signal and the valve opening θth detected at the previous TDC signal.
Let θru=θth−θthn−i. Hey, this Δ
Calculation of the θ value is performed by using a clock signal in which pulses are generated at one-step time intervals as a sampling signal in place of the valve opening value θth detected every time a pulse of the TDC signal occurs, and detecting the value every time the clock signal pulse occurs. Valve opening value θth
You may also be forced to calculate using tl-.

Next, it is determined whether or not this amount of change Δθ is larger than a predetermined acceleration determination value G+ (for example, +0.4 degrees/TDC) (step 2). If this answer is affirmative (Yes, that is, Δθi
h>c; If 10 is established and it is determined that the engine operating state is in the acceleration region, it is determined whether the control variable rLAOoO value is greater than the value 3↓ (step 3).

The control variable nAOO changes its value from 0 to 1 in step 15, which will be described later, every time a TDC signal is generated immediately after entering the acceleration region.
This is a variable that is added in increments. In other words, the determination in step 3 is to determine whether or not a time period corresponding to 4 TDC signals has elapsed since entering the acceleration region.

If the answer to step 3 is negative (A'O), that is, if the value of the control variable AOO is 0.1.2.3, then the value of the control variable WAOO is O. It is determined whether or not (step 4).

If the answer to step 4 is affirmative (Ye, ?), that is, if the engine operating state is in the acceleration region and the value of the control variable rLAOO at that time is O, then immediately after the TDC signal enters the acceleration region this time. It can be determined that the first T D (,' is a signal. In such a case, the following step 5
- 11, whether or not the operating state of the engine at the time of the previous TDC signal was in the fuel cut (fuel cutoff) operating range, and whether the engine rotation speed Nε obtained from the value Me counted at the time of the current TDC signal is equal to or higher than the predetermined rotation speed. Depending on whether or not the current TDC signal is reached, a set of TAOO tables optimal for the operating state of the acceleration region entered immediately before the current TDC signal is selected.

Therefore, first, in step 5, it is determined whether or not the operating state of the engine at the time of the previous TDC signal was a fuel cut, and if the answer is affirmative (Yg, y), that is,
If there was a fuel cut last time, then TDC this time.
The engine rotation speed Ng calculated at the time of the signal is the predetermined rotation speed #A
aa, (for example, 1.5007-) is determined (step 6).

If the answer to step 6 is affirmative (1'gz), that is, if there was a previous fuel cut and Ntt>Nhaa holds true, proceed to step 7 and perform the fourth set of 7'AOO.

Select a table group, and if the answer is negative (No), that is, if there was a previous fuel cut and N6≦NAOO1, proceed to step 8 and select 7'AOO of the second set.

Select a group of tables.

If the answer to step 5 is negative (NO), that is, if the fuel was not cut last time, then proceed to step 9, and similarly to step 6 above, check whether the engine speed Hg is higher than the predetermined rotation speed A'AOO, Determine whether or not.

If the answer to step 9 is affirmative ()'g, p), that is, if there was no previous fuel cut and Ne>Nhaal holds true, proceed to step 10 and perform the third set of TAOO
3 table groups are selected, and if the answer is negative (#o), that is, if it was not the previous 7 uwel cut and N6≦NAOO1, proceed to step 11 and select the 7'AOO of the first set.
, select the table group.

Depending on the determination result in step 5, that is, whether the engine operating state directly enters the acceleration region from the 7 fuel cut region or enters the acceleration region while in the fuel supply operation region, a set of different 7 The reason for selecting the 'AOO table group is as follows.

When the engine is operated at 7 fuel cut, the fuel adhering to the inner wall of the intake pipe evaporates.

For this reason, in the early stages of resuming fuel supply by releasing the fuel cut, if the amount of fuel is not increased until the fuel adhering to the intake pipe is saturated, the air-fuel ratio A/F of the mixture taken into the combustion chamber will decrease. will essentially become lean. Also, when operating at 7 fuel cut, residual C in the cylinder
Ot disappears, and the air-fuel ratio, 4/F, becomes lean as well. Therefore, if the state before entering the acceleration region is 7 fuel cut, it is necessary to increase the amount of fuel compared to the case where there is no fuel cut. The flock is being prepared.

Further, the reason why different sets of TAOCJ tables are selected depending on the engine rotational speed Net in step 6 or 9 is that the amount of fuel required by the engine differs depending on the operating state during acceleration.

The first to fourth table groups TAOO, ~TAO
As shown in FIG. 8, O is a table group provided for each value of the control variable nAOO, that is, for each progression of the TDC signal. In other words, each group of tables TAoai<i=x,
2.3.4) is the table Tho when AOO=O
When ci-6 is rLAOO=1, table TA
00 L −1 is “table T when AOO=2”
Aoai-.

, and when nAOO=3, tape kTAOOi
-B is selected. Each of these
The pull TAOOi-1()°=0.1.2.3) has a correction value 7'A O corresponding to the amount of change Δθ in the throttle valve opening.
O is set.

Returning to FIG. 7, when any of the table groups 7'AOOi is selected in step 78, 1o or 11, the process proceeds to step 12, where the table TAOOz- corresponding to the value of the control variable rLAOO is selected. jf: is selected, and TACCfL corresponding to the actual variation Δθ of the valve opening θth of the throttle valve 3 calculated in step 1 is read from the selected table TAOOJ.

If the answer to step 4 is negative (#O), that is, the control variable r
LA[j (If j is one of the values 1, 2, or 3, proceed to step 13 to select the table group TAOCi of the same set of the previous TDC signal, and then proceed to step 1 described above.
Proceed to step 2. In other words, the first T immediately after entering the acceleration region
When a DC signal is generated (CrLAoo=o), select the table group 7'AOOi that matches the operating state at that time (step 7.8.10 or 11) and extract the TAOO value from the first table rhoai-6 of the table group. (Step 12). Then, from the next TDC signal, the TAOO values are read out from the tables corresponding to the values of the control variables '&AOO of the same table group in the order in which the TDC signal is generated.

In step 12, 7'ACOf'ii fi' is read out, and the process then proceeds to step 14, where the rhac term (TAOOx K, ) in the above-mentioned equation (1) is calculated. Then, the value 1 is added to the value of the control variable rLAco described above (step 15), and the execution of this program is ended.

If the determination result in step 3 is affirmative (Yez), that is, if 4 TDC signals have elapsed since entering the acceleration region, it is determined that the fuel correction period during acceleration has elapsed, and step 2
If the answer is negative (CNO), that is, if Δθru≦G+, it is determined that the engine is in a region other than the acceleration operation region,
In either case, the value of the fuel correction variable 7'AOO during acceleration is set to 0 (step 16), and the value of the control variable nAO
The OO value is reset to O (step 17), and the execution of this program is ended.

7' calculated in step 14 or 16 of this program
The valve opening time TOUT of the fuel injection valve 6 is calculated by another control program based on the above-mentioned equation (1) using the ACO term, and the amount of fuel corresponding to the calculated value TOUT is supplied to the engine.

Figure 1 shows a case where fuel supply control according to the above embodiment is performed when an internal combustion engine, which is mounted on a mount on a test stand and is in a decelerating state, shifts to an accelerating state by opening the throttle valve. It shows changes in the displacement position of the engine mount over time, etc. As shown in Figure 1 (C), when the throttle valve opening increases and enters the acceleration region,
At the initial stage of entry, the valve opening time TOUT (FIG. 1(h)) of the fuel injection valve is corrected by the TAOO value. This TAOO value is a value corresponding to the amount of change Δθ of the valve opening θth of the throttle valve at that time.
) is read from another table. That is, 7'A
The OO value is determined as a function of the above-mentioned change amount Δθ path and time.

Therefore, a rapid increase in torque is obtained after acceleration, and the time until the engine speed N# starts to increase, that is, the 17Ne signal starts to decrease in FIG. can be shortened to 4 TDC signals between points A and B.

Moreover, the increase in fuel amount, that is, the fuel increase correction value TAOO'
Since it is determined as a function of i waiting time, it is possible to control the amount of increase in torque and the timing of increase in torque due to increases in filling efficiency and fuel amount. Furthermore, an increase value of 2 to 4 times (5 to 10 times if the fuel is cut off immediately before) is added to the reference value (Ti Therefore, the period during which the initial torque increase occurs (the period between time point 8 in FIG. 1(e) and time point 8) appears early after the engine acceleration is detected (time point A in FIG. 1). Further, since the charging efficiency at the initial stage of acceleration is low, a small initial torque increase can be obtained. This small initial torque increase makes it possible to eliminate backlash in the gears of the drive system without causing shock, and the position of the engine mount is adjusted at an early point after acceleration is detected (point B in Figure 1). It is brought to an intermediate position (position near time B in FIG. 1(g)) on the way to the stable position on the side (displacement position 3'o in FIG. 1(g)). Then, until the charging efficiency actually increases and the increase in effective torque necessary for acceleration is obtained, the amount of fuel that is sufficient to maintain the position of the engine mount, which has been moved to the intermediate position described above, is supplied. . As a result, the displacement of the engine mount portion, that is, the displacement that occurs when the engine attempts to rotate about the crankshaft at the mount position becomes gentle as shown in FIG. 1 (#). Therefore, the shock to the driver due to displacement of the engine mount and backlash of gears etc. during acceleration can be alleviated.

In addition, as is clear from FIG. 1(d), in the conventional example shown by the dotted line, the engine collides with the engine mount at time C, causing the engine to return to the opposite direction of the engine mount and return to a stable position during acceleration. 1(g), the transmission of acceleration torque to the drive system is delayed. In the present invention, as shown by the solid line, the displacement position of the engine mount is biased to an intermediate position on the way to the stable position during acceleration (displacement position y in Fig. 1 (g)) before the effective torque increase occurs. Therefore, acceleration torque is obtained at the same time as the increase in effective torque is generated, and acceleration performance is also improved.

Figure 9 shows the results of a funny running test, in which an internal combustion engine mounted on a mount on a vehicle chassis, whose engine speed is in the low engine speed range, more specifically around 150 orpm, is accelerated by the opening operation of the throttle valve. Figure 7 shows changes over time in the displacement position of the engine mount when the fuel supply control shown in Figure 1 is performed when transitioning to the 10th state.
The figure shows changes over time in the displacement position of the engine mount when an internal combustion engine in substantially the same low engine rotation range is accelerated by conventional fuel supply control. According to the conventional fuel supply control during acceleration, the acceleration increase correction value 7'Aoa is set as a function only of the throttle valve opening speed value Δθ, as shown in FIG. Approximately 8 TDC signal pulses are generated (time B in Figure 10) from the time of detection (time A in Figure 10), an increase in torque effective to accelerate the engine occurs, and then the position of the engine mount changes. It is rapidly displacing. Due to this rapid displacement, the engine repeatedly collides with the chassis side mound HC, and gradually changes its displacement position to a stable position on the acceleration side (10th position).
It is made to converge to the displacement position yl) in figure (g).

On the other hand, in FIG. 9 illustrating the fuel supply control method to which the present invention is applied, from the time when an operating state in which the engine should be accelerated is detected (time A in FIG. 9), to the time when an increase in torque effective for accelerating the engine occurs. Only during the period up to (time point B in FIG. 9), accelerated increase is performed using the accelerated increase correction value TAOO,
Moreover, since the acceleration increase correction value TAOO is decreased every time a TDC signal pulse is generated (shaded area in Fig. 9 Ch),
The effective torque increase in the engine acceleration pressure occurs at an earlier time than in FIG. 10, that is, in the embodiment, it occurs at the fourth TDC signal pulse from time A. Also, regarding the displacement of the engine mount, its position is temporarily held at an intermediate position on the way to the acceleration-side stable position (displacement position y+ in Figure 9) at time B, and then rapidly converges to the acceleration-side stable position. Therefore, the acceleration shock is almost eliminated, and the increase in engine torque effectively acts on engine acceleration, and the engine acceleration is significantly faster than that in FIG. 10.

The shock during acceleration occurs when the engine accelerates from a low-load operating state, such as during deceleration when the mixture is made lean or the fuel is cut off, or when the engine is in a low-speed operating range (for example, when the engine speed is below 3000 m/s). The TAOO table group is similar to the conventional acceleration increase characteristic because the displacement position of the engine mount does not change significantly due to the 7 riction of the drive system during acceleration from cruising other than this range, for example, 3000 γ pm or more. (For example, the 8th
TAOO, table group) shown in the figure may also be provided.

In the above embodiment, whether or not the operating state of the engine has entered the acceleration region is detected based on the amount of change Δθ in the throttle valve opening, but the present invention is not limited to this. However, the acceleration driving state may be detected by other means, such as an accelerator pedal position detection means.

(Effects of the Invention) As detailed above, according to the fuel supply control method during acceleration of an internal combustion engine of the present invention, when an acceleration request signal from an engine in a low load operating state is detected, the acceleration request signal During the period from when the engine is detected until the amount of intake air actually supplied to the engine, which increases with the opening of the throttle valve, reaches the value required to generate an increase in torque effective to accelerate the engine. The amount of fuel to be supplied is corrected by increasing the amount of fuel supplied based on the acceleration increase value, and this acceleration increase value is set to decrease every time a trigger signal pulse occurs at each predetermined crank angle position of the engine. It is possible to shorten the time delay from detection of a request signal to generation of effective acceleration torque, and furthermore, it is possible to improve acceleration performance without generating shock during acceleration.

[Brief explanation of the drawing]

Figure 1 shows the engine rotational speed Ng when acceleration fuel supply control is performed according to the method of the present invention to an internal combustion engine in a decelerating state.
FIG. 2 shows the engine rotation pNe and the position of the engine mount when acceleration fuel supply control is performed using the conventional method to an internal combustion engine in a decelerating state. 3 is a graph showing the relationship between throttle valve opening speed Δθ and acceleration increase correction value TACC according to the conventional fuel supply control method during acceleration; FIG. A block diagram showing the overall configuration of a fuel supply control device to which the method is applied, FIG. 5 is a partial front view of the engine illustrating the state in which the engine is mounted on the chassis side mount, and FIG. 6 is the electronic control shown in FIG. 4. Units)
(ECU), FIG. 7 is a flowchart explaining the procedure for setting the value of the acceleration increase correction variable TAOO according to the present invention, and FIG. 8 is the determination of the acceleration increase correction variable value TAOOf according to the present invention. A graph showing a group of tables, FIG. 9, shows the engine rotational speed Ng and the position of the engine mount when acceleration fuel supply control is performed according to the method of the present invention to an internal combustion engine installed in an actual vehicle and operating at low rotational speed. Fig. 10 is a timing chart explaining each time change, and shows the engine rotational speed Ne and the engine mount when acceleration fuel supply control is performed using the conventional method to an internal combustion engine installed in an actual vehicle and operating at low rotational speed. 3 is a timing chart illustrating each change in position over time. 1... Internal combustion engine, 2... Intake passage, 3... δ
Throttle valve, 4... Throttle valve opening sensor, 5...
・Electronic control unit, 6...Fuel injection valve, 1
DESCRIPTION OF SYMBOLS 1... Engine rotation angle position sensor, 50... Vehicle chassis side mount, 51... Mount rubber, 503...
CpU. 507...ROM0 Applicant Honda Motor Co., Ltd. Agent Patent Attorney Satoshi Watanabe Onma Kanji Nagato

Claims (1)

[Scope of Claims] 1. A required amount of fuel for an internal combustion engine having a throttle valve disposed in the middle of an intake passage in synchronization with a trigger signal pulse generated at each predetermined crank angle position according to the operating state of the engine. In the fuel supply control method for injecting and supplying a The fuel amount is increased by the acceleration increase value only for a period until the intake air amount supplied to the engine reaches a value necessary to generate an effective torque increase to accelerate the engine, and the fuel amount is corrected in this way. 1. A method for controlling fuel supply during acceleration of an internal combustion engine, characterized in that the acceleration increase value is set to decrease every time a pulse of the tri-force signal is generated. 2. The fuel supply control method during acceleration of an internal combustion engine according to claim 1, wherein the low-load operating state is a state in which the engine rotational speed is equal to or lower than a predetermined rotational speed. 3. The fuel supply control method during acceleration of an internal combustion engine according to claim 1, wherein the low-load operating state is a deceleration operating state.