JPS6161938A - engine control device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a control device for an automobile gasoline engine, etc., and particularly includes an electronic control device and controls the amount of fuel supplied to the engine according to the amount of accelerator operation by the driver. The present invention relates to an engine control device that independently controls the amount of intake air.

[Background of the invention]

When an internal combustion engine such as a gasoline engine runs continuously, the air-fuel ratio (hereinafter referred to as A/F), which is the ratio of air and fuel in the intake mixture, is
) is desirably kept at a predetermined value accurately.

By the way, in automobile engines such as Kallin,
The amount of intake air is controlled by operating a throttle valve that is mechanically linked to the accelerator pedal, and if a carburetor is used, the amount of fuel corresponding to this amount of air is mechanically controlled.
When an electronically controlled fuel injection device is used, a method has been used in the past in which the A/F is determined electrically, thereby obtaining the required A/F.

However, the specific gravity of air and fuel such as gasoline is significantly different, and due to the difference in inertia accompanying the supply operation, changes in the amount of fuel cannot follow changes in the intake air amount during transient operations, and therefore, the above-mentioned In the conventional method, A in the transient state
/F? There is a problem that 111 (goods) cannot be obtained sufficiently, and for this reason, for example, when accelerating VC, once A/
However, during deceleration, the A/F became rich (-floating), making it impossible to maintain the correct A/F'.

Therefore, in order to eliminate the drawbacks of the conventional methods described above, we developed a mixture supply system that can be called an intake air amount advance control method and a fuel amount follow-up control method. A mixture supply system using an air amount follow-up control method is disclosed in Japanese Patent Application Laid-Open No. 53-40131 and Japanese Patent Application Laid-Open No. 57-91.
This method has been proposed in Publication No. 345 and the like.

However, even in such a conventional fuel quantity advance control system, the details of the detailed control 1 in its implementation are not disclosed, and there is a problem that sufficient driving characteristics cannot be obtained if applied as is. For example, when changing the gear required when accelerating or decelerating a car, the accelerator pedal is suddenly released and then depressed again, but at this time, the A/F is simply changed due to the amount of fuel in advance. Even if control is performed to maintain the speed at a predetermined value, the sense of deceleration and acceleration will be insufficient and sufficient drivability will not be obtained.

[Purpose of the invention]

The present invention was made in view of the above circumstances, and its purpose is to obtain sufficient engine response characteristics even when a sudden accelerator operation is performed such as during a gear change operation, and to provide a good driving feel. is to provide an engine control device that can keep the ring running.

[Summary of the invention]

In order to achieve this object, the present invention monitors the control state of the engine, and when the control state of the engine becomes a transient state where it changes significantly, the relationship between the fuel supply firefly and the intake air amount taking A/F into account is determined. is modified so that control is performed based on the necessary acceleration and deceleration of the engine.

[Embodiments of the invention]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An engine control device according to the present invention will be explained in detail below using illustrated embodiments.

FIG. 1 is a block diagram of an engine system to which an embodiment of the engine control device according to the present invention is applied. In this figure, 1 is an engine, 2 is an intake pipe, 3 is a control valve, 4 is a throttle actuator, and 5 is an engine system. is an injector (fuel injection valve), 6 is a valve opening sensor, 7 is a throttle chamber, 8 is an accelerator pedal, 9 is an accelerator position sensor, 10
is a control circuit, 11 is a cooling water temperature sensor, and 12 is an A/F
Sensor; 13 is the rotation speed sensor built into the distributor, 14 is the UilP air, 15 is the tsuyuel tank, 1
6 is a fuel pump, 17 is a fuel pressure regulator, and 18 is a lever for driving a throttle valve.

The flow of intake air to the engine 1 is controlled by changing the opening degree of the throttle valve 3 using a throttle actuator 4 .

Pressurized fuel pumped from a tank 15 by a fuel pump 16 is introduced into the injector 5, and the pressure of the fuel at this time is kept constant by a regulator 17. Then, the injector 5 is driven by drive<S Ti.
When the drive signal T+ is operated electromagnetically, an amount of fuel is injected into the throttle chamber 7 according to the time period during which the drive signal T+ is supplied.

The actual opening degree of the throttle valve 3 is detected by the throttle valve opening degree sensor 6, and is inputted to the control circuit 10 as an opening degree signal θTll.

When the accelerator pedal 8 is depressed, the accelerator position sensor 9 detects the depressed position, and an accelerator position signal θ^C is input to the control circuit 10.

When the engine 1 rotates, the rotation speed is detected by the rotation speed sensor 13, the rotation speed signal N is input to the control circuit 10, the temperature of the cooling water is detected by the temperature sensor 11, and the engine temperature signal TW is input to the control circuit. 10 is input.

When the engine 1 rotates and exhaust gas flows into the exhaust pipe 14, A/l! A signal 14fy representing the output A/F' is detected by the sensor 12 and input to the control circuit 10.

The control circuit 10 receives a position signal θmC representing the applied position of the accelerator pedal 8 from the accelerator position sensor 9, and uses this signal θmC, the rotational speed signal N, and the warm signal Tw to determine the fuel amount. is calculated, and a drive signal IIJ with a corresponding pulse width TP is output to the injector 5 to supply a predetermined amount of fuel into the throttle chamber 7, and the intake air amount Wt is calculated based on the calculated fuel sound.
n, a corresponding drive signal θTll is output to the throttle actuator 4, the opening degree of the soft valve 3 is controlled to a predetermined value, the total intake air amount is controlled to a predetermined value, and the fuel is controlled as in the prior art. The mixture supply A8 system (4)l is carried out based on quantity advance control and intake air quantity follow-up control system.

FIG. 2 shows an embodiment of the i#+ control circuit 10, in which the ROM and R
C that has a built-in AM and constitutes a microcomputer
PU, Ilo that performs data input/output processing, and each input circuit INA~i that performs waveform shaping functions, etc.
It consists of an NC, an output circuit DR, etc.
) 5ens 1 to 6 via signals θTl, θmuC, N
, TV, EAF, etc., and outputs the driving signals T+, θH, etc. from the output circuit.

Note that the fuel pump 16 is supplied with a signal that turns on only when the engine is started and when the engine is rotating, and the CLTeH is a clutch that is provided assuming automatic operation control of the transmission. actuator.

Here, to explain the throttle actuator 4, this actuator 4 may be of any type as long as it has good responsiveness and provides the necessary resolution.
For example, a stepper motor, a DC motor, a negative pressure servo, a linear solenoid, etc. may be used.

FIG. 3 shows an example of a throttle actuator using a direct current 0TV motor, in which the rotation of a direct current motor 40 is transmitted at a reduced speed from a gear 41 to a gear 42, which engages with a female thread formed in the center hole of this gear 42. The throttle valve 3 is fully opened and closed by moving a male threaded rod 43 in the direction of the arrow and pushing the lever 18 of the throttle valve 3 with a push rod 44.

In addition, various methods can be considered to control the DC motor 40 at this time, but as an example, in order to enable digital control by the control circuit IO including a computer, the signal θTH is shown in FIG. A pulse signal as shown is used, and the opening degree of the throttle valve 3 can be controlled by the number of pulse signals.

As is well known, the injector 5 is generally controlled by pulse signals, and an example of the characteristics thereof is shown in FIG. Here, the pulse width Tp refers to the pulse width of the drive signal Ill and the valve opening time of the injector 5, and the fuel injection amount refers to the amount per pulse.

For reference, the relationship between the throttle valve opening degree θtg and the opening area of the throttle valve is shown in FIG. 6, which shows a non-linear characteristic.

Moreover, FIG. 7 shows the characteristics of the A/F sensor 12, and the output A/F (this is expressed as λ) varies linearly depending on the residual oxygen concentration in the exhaust gas in the exhaust pipe 14, etc. A signal Lv proportional to can be obtained. In addition, λ
It goes without saying that =1.0 represents the stoichiometric air-fuel ratio of 14.7. By the way, in this embodiment, the basic operation of engine control is shown in Fig. 8, Fig. 91El, and Fig. 10. A/F feedback control is performed based on the three-pole map shown in
By comparing the λ map (8th ml') of these maps with the output λ given by the signal EAF, a map giving θTH in the direction in which they match (Fig. 9) is obtained.
It is executed by modifying and replacing the maps (Fig. 10) that give Note that these maps represent n types of accelerator openings θmC and m, respectively.
The λ map shown in Fig. 8 is a combination of the accelerator opening θm and the engine speed N. The value of λ considered to be optimal for each combination is written in advance.

In addition, the θTH map in Fig. 9 shows the required valve opening to always provide the optimum amount of intake air for each combination of accelerator opening θm and engine speed N. θTH is calculated in advance.

Therefore, the TP map in Fig. 10 calculates the value of λ, which is also given by the λ map, depending on the intake air amount given by the θTH map, for each combination of accelerator opening θm C and engine speed N. TP is written in advance to provide the fuel supply amount necessary to achieve an output λ matching . Note that only the TP map is written in a non-destructive and rewritable memory such as LAM (power backup).

Next, the operation of this embodiment as a whole will be explained with reference to the flowchart shown in FIG.

The processing according to this flowchart is executed by the microcomputer of the control circuit 10 at predetermined fixed time intervals or in synchronization with the rotation of the engine.
In ■, data θAC,N for each building.

Take in TV, MF from each sensor, etc., and use ■ to map each (Fig. 8, Fig. 9, Fig. 10)
is retrieved and data θTi1l, TP, and λ are retrieved.

In ■, the key switch and data l1lW are checked to determine whether the engine operating state is in the starting state or in the warm-up state.If the result is NO, proceed to Difference Δθ between the previous value and the current 1 circle
Determine whether the engine control is in a steady operating state by checking the AC.

Here, if the result in (■) is YES, the operating state of the engine is neither starting nor warming up, and furthermore, there is no change in the depression operation of the accelerator pedal 8 by more than a predetermined amount, that is, the engine is in a steady operating state. This means that at this time, the processing for steady operation according to ~ is executed,
First, the data θTH and TP read from the map at
This allows direct control of the engine.

In the next step (■), the data given by Emr is compared with the data λ read from the map, and it is determined whether there is a difference of more than a predetermined value between the two, and if the difference is more than a predetermined value, When the difference has not reached a predetermined value, it is determined that correction is necessary, and when the difference has not reached a predetermined value, it is determined that correction is unnecessary.

Then, when it is determined that correction is necessary, execute ■ and T
Correct specified items in the p-map. In addition, T due to ■? As already mentioned, A/F feedback control is applied due to map correction.

On the other hand, if the result in ① is YES, at this time it is sufficient to carry out controls corresponding to engine starting and warming up, so the throttle valve opening θ that determines the amount of intake air? H' is set to be given by the product of engine temperature Tw and a predetermined proportionality constant by 8, and data TP' that determines the fuel supply amount is set.
is also a constant with temperature TV! Let it be given by At this time, considering the correction at the time of starting, this constant is determined as a function of the elapsed time t from the time the starting starts, that is, K, = f (t). This provides excellent starting performance.

By the way, the feature of the control of the present invention is that in this embodiment, when the result in (2) is NO, the processing in [phase] and (2) is performed. 12
As shown in the figure, the magnitude of change in data θTH (ΔθT)
To the constant given as a function of l, ,K.

The data θ read from the map is
rH, Tp are corrected, and corrected data θTl[, TP are calculated. Then, at the next 0, this correction data is output to the actuator 4 and the injector 5.

As a result, the data Δθ? During acceleration when H is 10, the constant becomes less than 1.0, which makes the A/F relatively rich and greatly improves the feeling of acceleration.
Similarly, during deceleration when the data Δθte becomes negative, the constant 4 becomes 1.0 or less, thereby making the A/F relatively lean and providing a sufficient sense of deceleration. Note that the data ΔθTH at this time is when the data θTH imported in ■ in the current process is A, and the data θTH imported in ■ in the previous process is B.
Δθ! It may be given by =A-B.

Also, the above is a case where it is applied to an engine with average physical properties, and depending on the engine, even in the -Δθτ■ region, A
There are cases where a better deceleration feeling can be obtained by setting / F at an acidic angle, and in such cases, -ΔθTM'p in Fig.
It is good to have the constant value 4 in the l region equal to or greater than 1.0.

Furthermore, instead of making the constant a function of the data ΔθTll, when the data ΔθTH exceeds a predetermined value, a value of 1.0 or less may be given as a function of time. .

By the way, as is clear from the above explanation, the essence of the present invention is that when the continuous rotation state of the engine enters a transient state, at that time, the data θτu, Tp used in the steady state
The point is that it is used after applying 46 positives to the above.

Therefore, for example, the contents of process (2) in the embodiment shown in FIG.
Assuming an automatic gear change mechanism that will be realized in the future, it will be necessary to open and close the throttle to quickly shift up and down, but in such cases it is especially unnecessary to change the entire amount of fuel supplied. It is known that this is not the case, and in this case, the constant 4 may be kept at 1.0.

Apart from these, due to a failure of the throttle actuator, a predetermined value (θTl()) may be generated between the data θTH given to the throttle actuator and the sensor output data θTa, as shown in FIG. If the above difference occurs, then you can set 4 to O as a constant and use 6h to back up the total number of women to 1t+il.

[Efficacy of invention]

As explained above, according to the present invention, when the engine operation enters a transient state, 1. lI, since the control data in the steady state is corrected, the control i'i [11] in the transient state can be arbitrarily changed as necessary, and the driving feeling actually obtained is always free from stress. It is possible to provide an engine opening device d that can easily control the engine speed and provide a good feeling of acceleration and deceleration.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an example of an engine system to which an embodiment of the engine control device according to the present invention is applied, FIG. 2 is a block diagram showing an embodiment of the control circuit, and FIG. 3 is an example of a throttle actuator. Figure 4 is an explanatory diagram showing an example of throttle actuator control, Figure 5 is an explanatory diagram showing an example of injector characteristics, and Figure 6 is an explanatory diagram showing an example of the injector characteristics. Characteristic diagram, 7th
Figure 1 is an explanatory diagram showing the characteristics of the A/1x sensor. FIG. 8 is a conceptual diagram showing an example of a λ map, FIG. 9 is a conceptual diagram showing an example of a θτH map, FIG. 10 is a conceptual diagram showing an example of a Tp map, and FIG. 11 is a conceptual diagram showing an example of a θτH map. 12 is an explanatory diagram showing an example of characteristics for determining constants, and FIG. 13 is an explanatory diagram of backup operation. 3...Finger valve, 4...Throttle actuator, 5...Injector, 6...
... Throttle valve opening sensor, 8... Accelerator pedal, 9... Accelerator position sensor, 10...
・Control circuit, 11...Temperature sensor, 12...
...A/) 1 sensor, 13...Rotary sensor. Agent Patent attorney Kurijibe Take (and 1 other person) Figure 3 Figure 4 Figure 5 Figure 0 Pulse width Tp (ms) Filial punishment and value 4 Figure 8 Time fist comparison N Figure 9 Number of rotations N Figure 10 Figure 11 Figure 12 Figure 13 θTH

Claims (1)

[Scope of Claims] 1. An engine control device that controls the amount of fuel supplied to the engine and the amount of intake air in accordance with the amount of accelerator operation by the driver based on a proportional relationship determined by the output air-fuel ratio of the engine. , a means for monitoring the control state of the engine, and a correction means for correcting the proportional relationship between the fuel supply amount and the intake air amount determined by the output air-fuel ratio, and the shaft stop is adjusted under transient engine control conditions. An engine control device characterized in that it is configured to operate a means. 2. The engine control device according to claim 1, wherein the transient engine control state is an engine acceleration/deceleration control state.