JPH1047123A - Throttle opening control device of engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve startability by giving the function of a throttle opener at the time of start to an electrically controlled throttle valve. SOLUTION: A water temperature Tw is detected at the time of start in a Step 11. When its water temperature Tw is in a prescribed range (A to B), an increasing amount TVOUP of a target throttle opening is set on the basis of the water temperature Tw in Steps 12, 13. A target throttle opening which is set on the basis of the increasing amount TVOUP, an acceleration manipulated variable during start is corrected to be increasing side, and thereby, the throttle opening is increased.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a throttle opening control device for a vehicle engine.

[0002]

2. Description of the Related Art In recent years, instead of a mechanical throttle valve linked to an accelerator pedal by a wire, a command signal from a control unit based on an accelerator operation amount (accelerator pedal depression amount) detected by an accelerator sensor and the like is transmitted via a motor. Electronically controlled throttle valves with controlled opening have been developed.

[0003]

By the way, when the engine is started, the startability can be improved by slightly opening the throttle valve even when the accelerator operation is not performed, and particularly, the oil tightness of the valve portion of the fuel injection valve is poor. Therefore, if fuel is dripped into the intake system during the idle time from engine stop to restart and the atmosphere is rich, startability deteriorates, but by increasing the throttle opening, Good startability can be obtained.

Conventionally, this function has been performed by a throttle opener, but since the throttle opener is a mechanical type, it has various restrictions and causes an increase in cost. In view of such circumstances, an object of the present invention is to enhance the function of an electronically controlled throttle valve by providing the electronically controlled throttle valve with a function of a throttle opener at the time of starting.

Another object of the present invention is to realize a more optimal start-up control by utilizing the characteristics of the electronically controlled throttle valve and to greatly improve the startability.

[0006]

Therefore, in the invention according to claim 1, as shown in FIG. 1, an accelerator operation amount detecting means for detecting an accelerator operation amount, and a target based on the detected accelerator operation amount. A throttle opening control device for an engine, comprising: target throttle opening setting means for setting a throttle opening; and throttle valve driving means for driving an electronically controlled throttle valve so as to attain the set target throttle opening. Starting time detecting means for detecting the start time of the engine, and water temperature detecting means for detecting the cooling water temperature of the engine,
And starting time correcting means for correcting the target throttle opening set by the target throttle opening setting means to an increasing side when the cooling water temperature is within a predetermined range at the time of starting. .

That is, at the time of starting, when the cooling water temperature is within a predetermined range, the target throttle opening set based on the accelerator operation amount is corrected to the increasing side, and the throttle valve is opened to start the engine. Improve the performance. According to a second aspect of the present invention, in the first aspect of the present invention, the starting correction means has an increase setting means for setting an increase in the target throttle opening based on at least the cooling water temperature at the start. Features.

By setting the increment of the target throttle opening on the basis of the cooling water temperature at the time of starting, a throttle opening suitable for the starting situation can be obtained. In the invention according to claim 3, in the invention according to claim 2, the increase amount setting means sets the increase amount of the target throttle opening to a value corresponding to a cooling water temperature at the time of starting and a standing time from engine stop to start. It is characterized by setting based on.

By setting the increment of the target throttle opening based on not only the cooling water temperature at the time of starting but also a value corresponding to the idle time from the stop of the engine to the start of the engine, in particular, the oil tightness of the fuel injection valve is reduced. If this occurs, the longer the standing time, the more fuel leaks.
The startability can be ensured by increasing the throttle opening.

According to a fourth aspect of the present invention, in the third aspect of the present invention, a difference between a cooling water temperature when the engine is stopped and a cooling water temperature when the engine is started is used as the value corresponding to the idle time. . When the standing time is short, the difference between the cooling water temperature when the engine is stopped and the starting cooling water temperature is small, and when the standing time is long, the difference between the cooling water temperature when the engine is stopped and the cooling water temperature when starting is large. This is because they are correlated. Note that when the leaving time is longer than a certain length, the difference does not increase any longer. However, when the leaving time becomes longer than a certain value, the engine completely cools down and the rich limit is expanded, so the throttle opening is increased so much. No need, so no problem.

According to a fifth aspect of the present invention, in the first aspect of the invention, the start-time correction means includes an increase setting means for setting an increase in the target throttle opening based on an elapsed time from the start of the start. It is characterized by having. By setting the increase amount of the target throttle opening based on the elapsed time from the start of the start, the longer the elapsed time, the worse the startability can be seen. In such a case, it is possible to open the throttle valve more and start the engine earlier.

According to a sixth aspect of the present invention, in the first aspect of the present invention, the start-time correction means initializes the increment of the target throttle opening based on at least the coolant temperature at the start. Means for increasing the target throttle opening in accordance with the elapsed time from the start of the start. Initially, the increment of the target throttle opening is set based on the cooling water temperature at the start.
Since it can be seen that the startability has deteriorated, it is possible to start more quickly by opening the throttle valve when the startability is deteriorated by increasing the startability in accordance with the elapsed time.

According to a seventh aspect of the present invention, in the invention according to the sixth aspect, the increment initial setting means sets the increment of the target throttle opening to the cooling water temperature at the start and the idle time from the engine stop to the start. It is characterized in that it is initialized based on the corresponding value. Thereby, the same operation as the invention according to claim 3 is obtained.

According to an eighth aspect of the present invention, in the invention according to the seventh aspect, a difference between a cooling water temperature when the engine is stopped and a cooling water temperature when the engine is started is used as the value corresponding to the idle time. . Thereby, the same operation as that of the invention according to claim 4 is obtained. According to a ninth aspect of the present invention, in the invention of the sixth to eighth aspects, a learning means for rewriting data of the increment initial setting means based on the increment of the target throttle opening at the end of the start is provided. It is characterized by having.

By learning the increase of the target throttle opening at the end of the start and reflecting the increase in the next control, a better startability can always be obtained irrespective of a change over time.

[0016]

Embodiments of the present invention will be described below. FIG. 2 shows an embodiment of the system configuration. An electronically controlled throttle valve 3 is provided in an intake passage 2 of the engine 1 to control an intake air flow rate.

The electronically controlled throttle valve 3 is driven by a motor 4 without being mechanically connected to an accelerator pedal. The motor 4 is operated by a command signal from the control unit 10. Each cylinder of the engine 1 is directly exposed to an intake manifold / branch portion, an intake port, or a combustion chamber.
An electromagnetic fuel injection valve 5 is provided. These fuel injection valves 5 are energized and opened by a drive pulse signal output at a predetermined timing in synchronization with engine rotation from the control unit 10, and inject fuel adjusted to a predetermined pressure. Therefore, the fuel injection amount is controlled by the pulse width of the drive pulse signal.

Each cylinder of the engine 1 is also provided with an ignition unit 6, and these ignition units 6 perform an ignition operation in response to an ignition signal from a control unit 10. For controlling the electronically controlled throttle valve 3, the fuel injection valve 5, and the ignition unit 6, the control unit 10 includes an accelerator operation amount (accelerator pedal depression amount) Ac
, An engine speed sensor (crank angle sensor) 12 for detecting the engine speed Ne, an air flow meter 13 for detecting the intake air flow rate Qa, a cooling water temperature Tw
A detection signal is input from a water temperature sensor 14 or the like for detecting the temperature. In addition, signals are also input from an engine key switch (ignition switch) 15 and a start switch 16.

Here, the control unit 10
As a throttle opening control, as shown in a flowchart of FIG. 3 described later, a target throttle opening tTVO is determined based on an accelerator operation amount Ac, and the motor 4 is controlled by a command signal corresponding to the target throttle opening tTVO.
To control the electronically controlled throttle valve 3 so that the target throttle valve opening degree tTVO is achieved.

The control unit 10 controls the fuel injection amount by controlling the intake air flow rate Qa and the engine speed N.
From e, the basic fuel injection amount Tp = K * Q / N (K is a constant)
Is determined, and various corrections are made to this, so that the final fuel injection amount Ti = Tp * COEF (COEF is various correction coefficients)
Is calculated and controlled. Control unit 10
In the control of the ignition timing, an optimal ignition timing ADV is set and controlled by referring to a map based on the engine speed Ne and the basic fuel injection amount (load) Tp.

Next, the throttle opening control according to the present invention will be described with reference to the flowchart of FIG. This flow is executed every predetermined time. In step 1 (indicated as S1 in the figure, the same applies hereinafter), the accelerator sensor 11
Is read to detect the accelerator operation amount Ac. This part corresponds to the accelerator operation amount detecting means.

In step 2, the target throttle opening tTVO is set in a substantially proportional relationship from the accelerator operation amount Ac with reference to a table stored in advance. This portion corresponds to target throttle opening setting means. In step 3, the amount of increase TVOUP of the target throttle opening at startup set by the flowchart of FIG. 4 (or FIG. 5, or FIG. 7, or FIG. 8) described later is read, and the target throttle opening is calculated by the following equation. The degree tTVO is corrected to the increasing side. This part corresponds to the starting correction means.

TTVO = tTVO + TVOUP If no correction is necessary except at the time of starting, TVOUP
= 0 and no correction is made. In step 4, the motor 4 is driven by a command signal corresponding to the target throttle opening tTVO, and the target throttle opening tTVO
The electronically controlled throttle valve 3 is controlled so that This part corresponds to the throttle valve driving means.

Next, the setting of the increment TVOUP of the target throttle opening at the time of starting will be described with reference to a flowchart. FIG. 4 is a flowchart of the first embodiment.
Note that this flow is executed with a change from OFF to ON of the start switch 16 as a start-time detecting means as a trigger.
In step 11, the signal of the water temperature sensor 14 as the water temperature detecting means is read to detect the starting water temperature Tw.

In step 12, the detected starting water temperature Tw is detected.
Is within a predetermined range (A to B). Here, the lower limit value A is preferably lower than the lower limit value A.
The upper limit value B is 10 ° C., above which the water temperature is usually 60 to 80 ° C., for example. When it is out of the predetermined range (A to B),
Since no correction is performed, the process proceeds to step 15, where the increment of the target throttle opening is set to TVOUP = 0, and the process is terminated.

If within the predetermined range (A to B), step
Proceed to 13. In step 13, the increment TVOUP is set by referring to a predetermined table for the increment TVOUP of the target throttle opening in accordance with the starting water temperature Tw. here,
The lower the starting water temperature Tw, the larger the increase TVOUP. In step 14, the start switch 16 is turned off
Then, while the start switch 16 is ON (during start-up), the increment TVOUP is maintained.

Then, when the start switch 16 is turned off (starting is completed), the routine proceeds to step 15, where the increment of the target throttle opening TVOUP is set to 0, and the processing is terminated. By such control, when the engine is started and the water temperature is within a predetermined range, the target throttle valve opening tTVO
Is increased by an amount TVOUP corresponding to the starting water temperature Tw, so that the startability can be improved.

Here, the steps 12 and 13 together with the step 3 correspond to the starting correction means.
The portion 13 corresponds to the increment setting means. FIG. 5 is a flowchart of the second embodiment. Note that this flow is also executed by using a change from OFF to ON of the start switch 16 as a start-time detecting means as a trigger. In step 21, a signal from the water temperature sensor 14 as a water temperature detecting means is read to detect the starting water temperature Tw.

In step 22, the detected starting water temperature Tw is detected.
Is within a predetermined range (A to B). If it is out of the predetermined range (A to B), no correction is performed.
Proceed to 26 and increase the target throttle opening TVOV = 0
To end the process. If it is within the predetermined range (A to B), the process proceeds to step S23.

In step 23, the stored engine-stop water temperature Tw _END is read, and the difference ΔTw between the engine-stop water temperature Tw _END and the start-up water temperature Tw is ΔTw = Tw _END −T
Find w. The water temperature difference ΔTw correlates with the idle time from the stop of the engine to the start of the engine. The water temperature Tw _END when the engine is stopped is determined by the water temperature sensor according to the flowchart of FIG.
Detected from 14 signals and stored.

In step 24, an increase TVOUP of the target throttle opening is referred to in accordance with a water temperature difference Tw at start and a water temperature difference ΔTw between when the engine is stopped and when the engine is started, and the increase TVOUP is determined. Set. Here, the lower the starting water temperature Tw and the larger the water temperature difference ΔTw, the larger the increase TVOUP. In step 25, it is determined whether or not the start switch 16 has been turned off, and the increment TVOUP is maintained while the start switch 16 is on (during start-up).

When the start switch 16 is turned off (starting is completed), the routine proceeds to step 26, where the increment of the target throttle opening TVOUP is set to 0, and the processing is terminated. As described above, not only the water temperature Tw at the time of starting, but also the water temperature difference ΔT
Based on w, the increase amount of the target throttle opening TVUP
In particular, if the fuel injection valve has poor oil tightness, the longer the idle time, the greater the amount of leaked fuel. Can be secured.

Here, the steps 22 to 24 correspond to the starting correction means together with the step 3, and in particular,
24 corresponds to the increment setting means. FIG. 7 is a flowchart of the third embodiment. Note that this flow is also executed by using a change from OFF to ON of the start switch 16 as a start-time detecting means as a trigger. In step 31, a signal from the water temperature sensor 14 as a water temperature detecting means is read to detect the starting water temperature Tw.

In step 32, the detected starting water temperature Tw is detected.
Is within a predetermined range (A to B). If it is out of the predetermined range (A to B), no correction is performed.
Proceed to 35 and increase the target throttle opening TVOV = 0
To end the process. If it is within the predetermined range (A to B), the process proceeds to step 33.

In step 33, the increment TVOUP is set with reference to a table in which the increment TVOUP of the target throttle opening is determined in accordance with the elapsed time from the start of the start. Here, the increment TVOUP is set to ₀ until the elapsed time from the start of the start reaches the predetermined time T ₀ , and after T ₀ , the increment TVOUP is gradually increased with a constant gradient as time elapses.

In step 34, the start switch 16 is
The start switch 16 is set to O
While the value is N (during start), the process returns to step 33, and the increment TVOUP is reset according to the elapsed time from the start of the start. Then, when the start switch 16 is turned off (when the start is completed), the routine proceeds to step 35, where the increment of the target throttle opening TVOUP is set to 0, and the processing is terminated.

In this way, by setting the increase amount TVOUP of the target throttle opening based on the elapsed time from the start of the start, it can be seen that the longer the elapsed time, the worse the startability. Therefore, when the startability is deteriorated, it is possible to open the throttle valve more and start the engine earlier. Here, the steps 32 and 33 together with the step 3 correspond to the starting correction means, and particularly the step 33 corresponds to the increment setting means.

FIG. 8 is a flowchart of the fourth embodiment. Note that this flow is also executed by using a change from OFF to ON of the start switch 16 as a start-time detecting means as a trigger. In step 41, a water temperature sensor as water temperature detecting means
The signal 14 is read to detect the starting water temperature Tw. In step 42, the detected starting water temperature Tw is adjusted to a predetermined range (A to A).
B) It is determined whether it is within.

If it is out of the predetermined range (A to B), no correction is performed, so the routine proceeds to step 49, where the increment of the target throttle opening TVOUP is set to 0, and the processing is terminated. If it is within the predetermined range (A to B), the process proceeds to step 43. Steps
In 43, the engine-stopped water temperature Tw _END stored in memory
(Refer to the flowchart of FIG. 6), and the difference ΔTw between the engine stop water temperature Tw _END and the start water temperature Tw = Tw = Tw
Find _END- Tw. The water temperature difference ΔTw correlates with the idle time from the stop of the engine to the start of the engine.

In step 44, the basic increase LTVOUP of the target throttle opening is referred to in accordance with a predetermined map in accordance with the starting water temperature Tw and the water temperature difference ΔTw between when the engine is stopped and when the engine is started. Set the LTVOUP.
Here, the lower the starting water temperature Tw and the larger the water temperature difference ΔTw, the larger the basic increase LTVOUP.

In step 45, a time increase TTVOU of the target throttle opening is made according to the elapsed time from the start of the start.
P is referred to a predetermined table, and the time increment TTVO
Set UP. Here, until the elapsed time from the start of the start reaches the predetermined time T ₀ , the time increase TTVUP =
0, and after T ₀ , the time increment TTVUP is gradually increased at a constant gradient with the passage of time.

In step 46, the final increment TVOUP is set by adding the basic increment LTVOUP and the time increment TTVUP as shown in the following equation. TVUP = LTVOUP + TTVOUP In step 47, it is determined whether or not the start switch 16 has been turned off. While the start switch 16 is on (during start-up), the process returns to steps 45 and 46, and according to the elapsed time from the start of start, Reset the time increment TVOUP,
As a result, the final increment TVOUP is reset.

When the start switch 16 is turned off (when the start is completed), the process proceeds to step 48 if necessary, and learning is performed. That is, regarded as increment TVOUP the target throttle opening at present is a time of starting the end of the optimal increase in starting, as the next time, it starts from the beginning of startup in a predetermined time T in ₀ ends, the basic Increase LT
The VOUP map data (data corresponding to the current start-up water temperature Tw and the water temperature difference ΔTw) is rewritten according to the increase amount of the target throttle opening TVOUP at the present time at the end of the start-up.

Of course, this requires a basic increase LT
It is necessary to provide a VOUP map on a rewritable RAM so that the backup power supply circuit can store and retain the data even during engine key-off. Then, after learning, the process proceeds to step 49, where the target throttle opening degree increase T
VOUP = 0, and the process ends.

As described above, the starting water temperature Tw and the water temperature difference Δ
Based on Tw, the increase amount of the target throttle opening TVUP
Initialization is set, but it can be seen that the longer the elapsed time from the start of the start, the worse the startability.Therefore, if the startability is deteriorated by increasing the elapsed time, It becomes possible to open the valve more and start earlier.

Further, by learning the increase amount TVOUP of the target throttle opening at the end of the start and reflecting it in the next control, a better startability can always be obtained regardless of a change with time. Here, the steps 42 to 46 together with the step 3 correspond to the starting correction means, particularly the step 44 corresponds to the increment initial setting means, and the steps 45 and 46 correspond to the increment increasing means. Step 48 corresponds to a learning means.

[0047]

As described above, according to the first aspect of the present invention, the electric throttle valve is set based on the accelerator operation amount when the engine is started and the water temperature is within a predetermined range. By opening the throttle valve by correcting the target throttle opening to the increasing side, it is possible to obtain an effect that the startability can be improved.

According to the second aspect of the present invention, by setting the increment of the target throttle opening based on the water temperature at the time of starting, a throttle opening suitable for the starting situation can be obtained.
According to the third aspect of the present invention, by setting the increment of the target throttle opening in consideration of the idle time from the stop of the engine to the start of the engine, particularly when the oil-tightness of the fuel injection valve is poor, As the amount of leaked fuel increases, the opening degree of the throttle is greatly increased, and the startability can be secured.

According to the fourth aspect of the present invention, a value corresponding to the idle time can be obtained relatively easily from the difference between the engine-stop water temperature and the engine-start water temperature. According to the invention according to claim 5, by setting the increment of the target throttle opening based on the elapsed time from the start of the start, the throttle valve is opened more when the startability deteriorates and it takes time. As a result, the engine can be started quickly.

According to the sixth aspect of the present invention, the increment of the target throttle opening is initially set on the basis of the starting water temperature. Next, open the throttle valve more,
It is possible to start quickly. According to the seventh aspect, the same effect as that of the third aspect is obtained.

According to the eighth aspect, the same effect as that of the fourth aspect can be obtained. According to the ninth aspect of the present invention, by learning the increase in the target throttle opening at the end of the start and reflecting the increase in the next control, it is possible to always obtain better startability irrespective of a change with time. Can be

[Brief description of the drawings]

FIG. 1 is a functional block diagram showing a configuration of the present invention.

FIG. 2 is a system diagram showing an embodiment of the present invention.

FIG. 3 is a flowchart of throttle opening control.

FIG. 4 is a flow chart of a first embodiment for setting an increase at startup.

FIG. 5 is a flow chart of a second embodiment for setting an increase at startup.

FIG. 6 is a flowchart of stopping-time water temperature storage.

FIG. 7 is a flowchart of a third embodiment for setting an increase at startup.

FIG. 8 is a flowchart of a fourth embodiment for setting an increase at startup.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Engine 2 Intake passage 3 Electric throttle valve 4 Motor 5 Fuel injection valve 6 Ignition unit 10 Control unit 11 Accelerator sensor 12 Speed sensor 13 Air flow meter 14 Water temperature sensor 15 Engine key switch 16 Start switch

Claims (9)

[Claims] An accelerator operation amount detecting means for detecting an accelerator operation amount; a target throttle opening setting means for setting a target throttle opening based on the detected accelerator operation amount; A throttle valve driving means for driving an electronically controlled throttle valve so as to provide a throttle opening degree control device for an engine, wherein: a starting time detecting means for detecting when the engine is started; and a water temperature detecting means for detecting a cooling water temperature of the engine. And starting correction means for correcting the target throttle opening set by the target throttle opening setting means to an increasing side at the time of starting and when the coolant temperature is within a predetermined range. Engine throttle opening control device. 2. The engine throttle according to claim 1, wherein said starting correction means includes an increment setting means for setting an increment of the target throttle opening based on at least a cooling water temperature at the time of starting. Opening control device. 3. An increase setting means for setting an increase in the target throttle opening on the basis of a cooling water temperature at the time of starting and a value corresponding to an idle time from engine stop to start. 3. The throttle opening control device for an engine according to claim 2, wherein 4. The throttle opening control device for an engine according to claim 3, wherein a difference between a cooling water temperature when the engine is stopped and a cooling water temperature when the engine is started is used as the value corresponding to the idle time. 5. The engine throttle according to claim 1, wherein said starting correction means includes an increment setting means for setting an increment of the target throttle opening based on an elapsed time from the start of the starting. Opening control device. 6. The starting correction means includes an initial setting means for initially setting an increase in the target throttle opening based on at least the cooling water temperature at the start, and an increase in the target throttle opening from the start. 2. The throttle opening control device for an engine according to claim 1, further comprising means for increasing the amount according to the elapsed time. 7. The increase initial setting means initializes an increase in the target throttle opening based on a cooling water temperature at the time of starting and a value corresponding to an idle time from engine stop to start. 7. The throttle opening control device for an engine according to claim 6, wherein: 8. The throttle opening control device for an engine according to claim 7, wherein a difference between a cooling water temperature when the engine is stopped and a cooling water temperature when the engine is started is used as the value corresponding to the idle time. 9. A learning means for rewriting data of said increment initial setting means based on the increment of the target throttle opening at the end of the start. The throttle opening control device for an engine according to any one of the preceding claims.