JP2002081336A - Electronic throttle control device of internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve retreating running performance in an electronic throttle system when a throttle valve cannot pass through a whole closing position from a negative opening side at the start of an engine. SOLUTION: When the throttle valve 12 cannot pass through the whole closing position from the negative opening side at the start of the engine, an opening of the throttle valve 12 is controlled in a variable range on the negative opening side in response to an accelerator operation amount (this control is hereinafter called 'negative opening side control'). During the negative opening side control, the throttle valve 12 is driven in a short time to the positive opening side whenever a predetermined condition (for example, idling time during stopping of a vehicle) is satisfied, and thus, when the throttle valve 12 can pass through the whole closing position, negative opening side control is gradually returned to a normal control. At this time, a characteristic of a desired throttle opening for the accelerator operation amount is gradually returned to a normal state.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic throttle control device for an internal combustion engine which passes through a fully closed position and holds the throttle valve at a minus opening when the internal combustion engine (hereinafter referred to as "engine") is stopped. It is about.

[0002]

2. Description of the Related Art A conventional electronic throttle control device detects an amount of depression of an accelerator pedal by an accelerator sensor, sets a target throttle opening in accordance with an output signal of the accelerator sensor, and sets a target throttle opening (actual throttle opening). The throttle valve opening is controlled by a motor or the like such that the throttle opening) matches the target throttle opening. In such an electronic throttle control device, as disclosed in Japanese Patent Application Laid-Open No. 4-249678, the throttle valve is moved from a fully open position where the intake air amount is maximum to a fully closed position where the intake air amount is minimum, on the minus opening side. It has been proposed to be configured to be rotatable to a final stop position (opener opening degree) exceeding the above. Further, in this publication, when the motor or the throttle opening sensor fails, the power to the motor is cut off, and the throttle valve is fully closed by a spring force for urging the throttle valve to the minus opening side. A technique is disclosed in which a vehicle can be evacuated by turning over to a minus opening degree and holding the opener opening degree.

[0003]

In the above configuration, when the engine is started, the throttle valve is moved from the minus opening side to the full closing position to be driven to the plus opening side, so that the intake passage is closed while the engine is stopped. Due to icing or deposits generated on the wall surface, a situation may occur in which the throttle valve cannot pass through the fully closed position from the minus opening side when the engine is started. In such a situation, the control computer determines that the electronic throttle system is faulty, shuts off the power to the drive motor of the throttle valve, and sets the throttle valve to the maximum opening on the minus opening side (opener opening) by the spring force. To keep it. As a result, the amount of intake air at the time of failure is ensured, and evacuation traveling to the service factory is enabled.

However, in this configuration, the throttle valve is fixed at the opening degree of the opener during the limp-home running, and the amount of intake air becomes constant. Therefore, in order to control the vehicle speed during the limp-home running, it is complicated to mix fuel cut and the like. Therefore, there is a drawback that the evacuation traveling performance is poor.

The present invention has been made in view of such circumstances, and accordingly, an object of the present invention is to improve the limp-home running performance that is performed when the throttle valve cannot pass through the fully closed position from the minus opening side at the time of starting. An object of the present invention is to provide an electronic throttle control device for an internal combustion engine that can be improved.

[0006]

According to a first aspect of the present invention, there is provided an electronic throttle control apparatus for an internal combustion engine according to the present invention. If the throttle valve cannot pass through the fully closed position from the minus opening side at the time of starting, the opening degree of the throttle valve is controlled by the control means within the movable range on the minus opening side (hereinafter, this control is referred to as “ Minus side control ”). If you do this,
Even when the throttle valve cannot pass through the fully closed position from the minus opening side at the time of starting, the throttle valve is not fixed at the opener opening (maximum minus opening), and the opening of the throttle valve is set within the movable range on the minus opening side. It is possible to perform the limp-home running while controlling the intake air amount by controlling. Accordingly, it is not necessary to perform complicated fuel injection control in which fuel cut or the like is interwoven during evacuation traveling, so that control during evacuation traveling can be simplified and drivability during evacuation traveling can be improved.

In this case, the opening degree of the throttle valve may be controlled in the minus opening side movable range in accordance with the accelerator operation amount during execution of the minus opening side control. With this configuration, the throttle valve can be driven in conjunction with the accelerator operation during the execution of the negative opening degree control, and the drivability during the limp-home running can be further improved.

By the way, even when the throttle valve cannot pass through the fully closed position due to icing or deposits at the time of starting, the temperature around the throttle valve rises due to the heat radiation from the internal combustion engine with the lapse of time after the starting. Can be melted or the deposit softened. Therefore, there is a possibility that the throttle valve will eventually return to a state in which the throttle valve can pass the fully closed position even during the execution of the minus opening degree control.

Therefore, the throttle valve is temporarily driven to the positive opening side during the execution of the negative opening side control, and the control is returned to the normal control when the throttle valve passes the fully closed position. You may make it return. In this way, in the case of a temporary malfunction due to icing or deposit, when the cause of the malfunction has been resolved, the throttle valve is driven to the positive opening side to return to the normal control.

Further, the driving of the throttle valve to the positive opening side may be performed during idling while the vehicle is stopped, while the negative opening side control is being performed.
As described above, when the throttle valve is driven to the positive opening side during idling while the vehicle is stopped, it is possible to return to the normal control without affecting drivability at all.

Further, the driving of the throttle valve to the positive opening side may be performed at predetermined intervals during the execution of the negative opening side control. here,
The “predetermined interval” may be set by any one of, for example, the amount of rise in cooling water temperature, time, integrated value of travel distance, integrated value of consumed fuel, and the like. If the drive of the throttle valve to the positive opening side is performed at a predetermined interval during the execution of the negative opening side control, the cause of the temporary malfunction due to icing or deposit is eliminated. Thus, it is possible to quickly return to the normal control.

By the way, during the limp-home running, there is a possibility that the accelerator operation of the driver may be messy, so that if the control is returned to the normal control immediately, the vehicle may suddenly start due to excessive depression of the accelerator pedal. is there.

Therefore, it is preferable that the characteristic of the target throttle opening degree with respect to the accelerator operation amount is gradually returned to the normal state when returning from the minus opening side control to the normal control. With this configuration, immediately after returning from the minus opening side control to the normal control, the target throttle opening is set smaller than normal with respect to the accelerator operation amount. This can prevent the vehicle from suddenly starting. Moreover, since the characteristic of the target throttle opening with respect to the accelerator operation amount is gradually returned to the normal state after the return of the normal control, the driver's accelerator operation feeling can be gradually returned to the normal state. It is possible to smoothly return to the normal control without feeling uncomfortable feeling of the accelerator operation.

When returning from the negative opening control to the normal control, the upper limit guard value for limiting the maximum positive opening of the throttle valve may be gradually increased. . Also in this case, similarly to the case of the above-described claim 6, it is possible to prevent sudden start of the vehicle due to excessive depression of the accelerator pedal immediately after the return to the normal control, and to prevent the driver from feeling uncomfortable with the accelerator operation. It is possible to smoothly return to the normal control.

Further, when the frequency of execution of the minus opening side control becomes a predetermined frequency or more, the driving to the plus opening side may not be performed. In other words, in the case where the minus opening side control is performed many times, there is a possibility that a large amount of deposit is deposited on the inner wall of the intake passage, and therefore, the drive to the plus opening side is not performed. The opening of the throttle valve is controlled in the movable range on the minus opening side. In this case, the driver may be notified by turning on a warning light or the like to recognize the necessity of repair.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. First, the configuration of the electronic throttle system will be described with reference to FIGS. A throttle valve 12 is rotatably mounted in the middle of an intake pipe 11 of an engine (internal combustion engine) via a rotary shaft 13, and a motor 14 (throttle actuator) such as a DC motor is connected to the rotary shaft 13 of the throttle valve 12. Have been.
The driving force of the motor 14 causes the throttle valve 12
(Throttle opening) is controlled, and the throttle opening is detected by the throttle opening sensor 15.
The rotation shaft 13 of the throttle valve 12 and the motor 14 may be connected via a reduction gear mechanism.

A return spring 16 is mounted on one end of the rotary shaft 13 of the throttle valve 12 for urging the throttle valve 12 to rotate to the minus opening side. When the motor 14 is turned off, the spring force of the return spring 16 holds the throttle valve 12 in contact with an opener stopper (not shown) at the maximum minus opening (opener opening). Opener opening is, for example, -5 ° to-
It is set within the range of 10 °. In the normal control, the throttle valve 12 is controlled within a range from the throttle opening at idle near the fully closed position (0 °) to the maximum plus opening (for example, + 90 °). At the fully closed position, the gap (clearance) between the throttle valve 12 and the inner surface of the intake pipe 11 is minimized, and the amount of intake air is minimized.

An electronic control unit (hereinafter referred to as "ECU") 17 for controlling a motor 14 for driving the throttle valve 12 detects a throttle opening sensor 15 and an accelerator operation amount (an accelerator pedal depression amount). The output signal of the accelerator sensor 18 is input. ECU 17
Functions as a control means referred to in the claims. During normal control, feedback control of the motor 14 is performed by PID control or the like according to a target throttle opening set based on an accelerator operation amount detected by the accelerator sensor 18 or the like. Then, the throttle opening is controlled to the target throttle opening by the driving force of the motor 14.

Further, the ECU 17 executes the routines shown in FIGS. 3 to 7 so that when the throttle valve 12 cannot pass through the fully closed position from the minus opening side at the time of engine start, the ECU 17 adjusts the throttle according to the accelerator operation amount. The opening of the valve 12 is controlled within a movable range on the minus opening side (hereinafter, this control is referred to as “minus opening side control”), and a predetermined condition is satisfied during the execution of the minus opening side control. Each time, the throttle valve 12 is driven to the positive opening side for a short time, and when the throttle valve 12 can pass through the fully closed position, the control gradually returns from the negative opening side control to the normal control. Hereinafter, the processing contents of each routine of FIGS. 3 to 7 for executing this control will be described in detail.

[Main Routine] The main routine of FIG. 3 is repeatedly executed at predetermined time intervals after an ignition switch (not shown) is turned on. When this routine is started, first, in step 101, it is determined whether or not the fully closed position valve block determination flag is ON. This fully closed position valve lock determination flag is used when the throttle valve 12 is locked at the fully closed position and cannot pass through in the fully closed position valve lock determination routine of FIG. The flag is set to ON.

If it is determined in step 101 that the fully closed position valve block determination flag is OFF, the routine is terminated without performing the subsequent processing. If it is determined that the valve 12 cannot pass through the fully closed position),
In step 02, a negative opening side control routine shown in FIG. 5 described below is executed, and the opening of the throttle valve 12 is controlled in the negative opening side movable range according to the accelerator operation amount.

Thereafter, the routine proceeds to step 103, where it is determined whether or not the value of the number-of-minus-opening-side control execution counter is smaller than a predetermined value. The number-of-minus-opening-side control execution counter is the number of times that the throttle valve 12 has failed to pass the fully closed position when the ignition switch is turned on (that is, the negative opening degree), according to a minus-opening-side control execution number counting routine shown in FIG. (The number of executions of the side control) is counted.

If it is determined in step 103 that the value of the negative opening side control execution counter is equal to or larger than the predetermined value, the routine is terminated without performing the subsequent processing. In other words, when the minus opening side control is performed many times, it is possible that a large amount of deposits are accumulated on the inner surface of the intake pipe 11 or the like. Without performing, only the minus opening side control is performed, and the driver is notified by turning on a warning light, etc.
Make them aware of the need for repair.

On the other hand, if it is determined in step 103 that the value of the negative opening side control execution number counter is smaller than the predetermined value, the execution conditions of the fully closed position passing try process are satisfied in steps 104 to 106. Is determined.
The fully closed position passing try process is performed in step 107 described later.
This is a process in which the throttle valve 12 is driven from the minus opening side to the plus opening side for a short time to try to pass the fully closed position.

In the present embodiment, the execution condition of the fully closed position passing try process is to satisfy all of the following conditions. A predetermined time has elapsed since the previous fully closed position pass try processing (step 104). The engine operating state is idle (step 105). The vehicle is stopped (step 106).

If any one of these three conditions is not satisfied, the execution condition of the fully closed position pass try processing is not satisfied, and the subsequent processing is not performed.
This routine ends.

On the other hand, if all three conditions are satisfied, the execution condition of the fully closed position pass try process is satisfied, and the routine proceeds to step 107, where the fully closed position pass try process is executed. In the fully closed position passing try process, the throttle valve 12 is driven for a short time to the positive opening of the same air flow as the current air flow of the negative opening to try to pass the fully closed position.

Thereafter, the routine proceeds to step 108, where it is determined whether or not the throttle valve 12 has passed the fully closed position.
If the vehicle cannot pass through the fully closed position, the negative opening side control is continuously performed. If the throttle valve 12 has passed through the fully closed position as a result of the fully closed position passing try process, the routine proceeds to step 109, where a return control routine shown in FIG. I do. Then, in step 110, the fully closed position valve block determination flag is reset to OFF, and this routine ends.

Incidentally, as the execution condition of the fully closed position passing try process, only one or two of the following conditions may be used. Also, instead of the condition (predetermined time has passed since the previous fully closed position pass try processing), for example, the cooling water temperature has increased by a predetermined value or more since the previous fully closed position pass try processing, or The condition may be that the running distance integrated value or the consumed fuel integrated value has become equal to or more than a predetermined value from the previous fully closed position passing try processing, in other words,
It is sufficient that the fully closed position passing try processing is executed at appropriate intervals.

[Fully Closed Position Valve Lock Judgment] The fully closed position valve lock determination routine shown in FIG. 4 is repeatedly executed at predetermined time intervals after the ignition switch is turned on to determine whether the throttle valve 12 is locked at the fully closed position and cannot pass. The determination is made as follows. First, step 201
In steps 204 to 204, it is determined whether or not there is a possibility that the throttle valve 12 is locked at the fully closed position and cannot pass therethrough. Here, when all of the following four conditions are satisfied, it is determined that there is a possibility that the throttle valve 12 is locked at the fully closed position and cannot pass therethrough.

The target throttle opening is larger than a predetermined plus opening (step 201). The actual throttle opening detected by the throttle opening sensor 15 is not more than the fully closed position (0 °) (step 20).
2) The control duty DUTY (absolute value) of the motor 14 is larger than a predetermined value (step 203). The current (absolute value) of the motor 14 is larger than a predetermined value (step 204).

When the target throttle opening is larger than a predetermined plus opening, the motor 1
By determining whether or not the actual throttle opening remains on the minus opening side in spite of a large driving force to the plus opening side of No. 4, the throttle valve 12 is moved to the fully closed position. It is determined whether or not there is a possibility that the vehicle cannot be locked and cannot pass.

If at least one of these four conditions is not satisfied, this routine is terminated without determining that the valve is at the fully closed position. On the other hand, if all four conditions are satisfied, the throttle valve 12
It is determined that there is a possibility that the throttle valve 12 may not be locked at the fully closed position and may not be able to pass. Count.

Thereafter, the routine proceeds to step 206, where it is determined whether or not the time during which the throttle valve 12 cannot pass through the fully closed position has exceeded a predetermined time, based on whether or not the value of the lock determination counter has exceeded a predetermined value. Then, when the value of the lock determination counter exceeds a predetermined value, it is finally determined that the throttle valve 12 is locked at the fully closed position, and the routine proceeds to step 207, where the fully closed position valve block determination flag is turned on. And the routine ends.

[Negative Opening Side Control] The negative opening side control routine of FIG. 5 is executed in step 102 of the main routine of FIG. 3, and is executed when the throttle valve 12 cannot pass the fully closed position from the negative opening side. The negative opening side control is performed as follows. First, step 301
Then, the target throttle opening degree characteristic map at the time of the normal control in FIG. 8 is searched to calculate the target throttle opening degree θP under the normal state according to the current accelerator operation amount. After this,
Proceeding to step 302, a target minus opening .theta.N for obtaining the same air flow rate as the target throttle opening .theta.P is calculated. In the next step 303, it is determined whether or not the absolute value of the target minus opening .theta.N is larger than the opener opening. If it is larger than the opener opening, the routine proceeds to step 304, where the target minus opening θN is guarded by the opener opening, and the target minus opening θN is set to the opener opening, and this routine is terminated. I do. As a result, during execution of the negative opening side control, as shown in FIG. 9, the target negative opening θN in the movable range on the negative opening side (range from the fully closed position to the opener opening) according to the accelerator operation amount. Is set, and the opening of the throttle valve 12 is controlled to match this target minus opening θN.

[Counting the number of times the negative opening side control was performed]
6 is executed after a lapse of a predetermined time from the turning on of the ignition switch. First, at step 401, it is determined whether or not the throttle valve 12 has passed the fully closed position when the ignition switch is turned on. Is determined, and if the throttle valve 12 cannot pass through the fully closed position, the routine proceeds to step 402, where the minus opening side control execution number counter is counted up. As a result, the number of times that the throttle valve 12 has failed to pass through the fully closed position when the ignition switch is turned on (that is, the number of times of execution of the minus opening degree control) is counted.

[Return Control] The return control routine of FIG.
This is executed in step 109 of the main routine of FIG. 3, and when the throttle valve 12 passes through the fully closed position by the fully closed position passing try process, the control gradually returns from the minus opening side control to the normal control as follows. . First, in step 501, it is determined whether or not the target throttle opening θP in a normal state calculated according to the current accelerator operation amount is larger than a predetermined plus opening θPo (for example, 10 ° to 20 °). Throttle opening θP is predetermined plus opening θ
If Po or less, the process proceeds to step 506, where the final target throttle opening is set to the target throttle opening θP in a normal state. Thus, in a region where the target throttle opening θP under the normal state is equal to or less than the predetermined plus opening θPo, the final target throttle opening is set according to the accelerator operation amount.

On the other hand, in step 501, the target throttle opening .theta.
If it is determined that it is larger than Po, step 502
And adds a predetermined value α to the previous accelerator operation smoothing coefficient KA (i-1) to calculate the current accelerator operation smoothing coefficient KA
Update (i). KA (i) = KA (i-1) + α

Thus, as shown in FIG. 10, the number of times the driver depresses the accelerator pedal by a predetermined opening degree or more (that is, the number of times the target throttle opening .theta.P becomes equal to or more than a predetermined plus opening .theta.Po). Operation smoothing coefficient KA
(i) is increased by a predetermined value α.

After calculating the accelerator operation smoothing coefficient KA (i), the routine proceeds to step 503, where the accelerator operation smoothing coefficient K
It is determined whether or not A (i) is larger than 1 which is the upper limit guard value. If the accelerator operation smoothing coefficient KA (i) is larger than 1, the routine proceeds to step 504, where the accelerator operation smoothing coefficient KA (i) ) Is set to 1. As a result, the accelerator operation smoothing coefficient KA (i) is set in the range from 0 to 1.

Thereafter, the routine proceeds to step 505, where the final target throttle opening is calculated by the following equation using the accelerator operation smoothing coefficient KA (i). Final target throttle opening = (θP−θPo) × KA (i)
+ ΘPo θP: target throttle opening under normal conditions θPo: predetermined plus opening

In this case, the accelerator operation smoothing coefficient KA (i) is determined according to the number of times the driver has depressed the accelerator pedal by a predetermined opening degree or more (the number of times the target throttle opening degree θP has become a predetermined plus opening degree θPo or more). Since the value gradually increases and approaches 1, the characteristic of the final target throttle opening degree with respect to the accelerator operation amount gradually returns to the normal state when returning from the negative opening side control to the normal control.

In this embodiment described above, when the throttle valve 12 cannot pass through the fully closed position from the minus opening side when the engine is started (when the ignition switch is turned on), the minus opening side control is performed to perform the accelerator operation. Since the opening of the throttle valve 12 is controlled in the movable range on the minus opening side in accordance with the amount, even when the throttle valve 12 cannot pass through the fully closed position from the minus opening side, the opening of the throttle valve 12 is opened. It is not fixed by the degree, and it is possible to perform the limp-home run while controlling the intake air amount by controlling the opening degree of the throttle valve 12 in the movable range on the minus opening side according to the accelerator operation amount. Accordingly, it is not necessary to perform complicated fuel injection control in which fuel cut or the like is interwoven during evacuation traveling, so that control during evacuation traveling can be simplified and drivability during evacuation traveling can be improved.

Further, in the present embodiment, the throttle valve 12 is driven to the positive opening side for a short time every time a predetermined condition is satisfied during the execution of the negative opening side control, whereby the throttle valve 12 is fully driven. When the vehicle can pass the closed position, the control returns from the negative opening control to the normal control.In the case of a temporary malfunction due to icing or deposit, when the cause of the malfunction has been resolved, the normal Control can be returned.

Further, when returning from the minus opening control to the normal control, the characteristic of the final target throttle opening with respect to the accelerator operation amount is gradually returned to the normal state. The final target throttle opening can be set smaller than usual with respect to the manipulated variable, preventing sudden start of the vehicle due to excessive depression of the accelerator pedal immediately after returning to normal control, and driving after returning to normal control. It is possible to gradually return the driver's accelerator operation feeling to a normal state, and smoothly return to the normal control without causing the driver to feel uncomfortable in the accelerator operation.

In the present embodiment, the characteristic of the final target throttle opening degree with respect to the accelerator operation amount is gradually returned to the normal state when returning from the minus opening side control to the normal control. When returning from the degree control to the normal control, the upper limit guard value for limiting the maximum positive opening of the throttle valve 12 may be gradually increased. Even in this case, the same effect as that of the present embodiment can be obtained.

Further, in this embodiment, the fully closed position passing try process is stopped when the number of times of execution of the minus opening side control exceeds a predetermined number. Is more than a predetermined number of times,
The fully closed position passing try process may be stopped.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of an electronic throttle system showing one embodiment of the present invention.

FIG. 2 is a diagram for explaining a rotation range of a throttle valve.

FIG. 3 is a flowchart showing the flow of processing of a main routine.

FIG. 4 is a flowchart showing a process flow of a fully closed position valve block determination routine;

FIG. 5 is a flowchart showing the flow of processing of a minus opening side control routine;

FIG. 6 is a flowchart showing the flow of processing of a routine for counting the number of times of execution of the minus opening side control.

FIG. 7 is a flowchart showing the flow of a process of a return control routine.

FIG. 8 is a diagram conceptually showing a target throttle opening characteristic map during normal control.

FIG. 9 is a diagram conceptually showing a target minus opening degree characteristic map at the time of minus opening side control.

FIG. 10 is a diagram showing the relationship between the number of times the driver steps on the accelerator by a predetermined opening degree or more and the accelerator operation smoothing coefficient KA.

[Explanation of symbols]

11 ... intake pipe, 12 ... throttle valve, 13 ... rotating shaft, 14 ... motor (throttle actuator), 15
... Throttle opening sensor, 16 ... Return spring,
17 ... ECU (control means), 18 ... Accelerator sensor.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) F02D 11/10 F02D 11/10 Q 41/22 310 41/22 310M 45/00 358 45/00 358K F term (Ref.) NA08 NC02 ND41 NE03 NE17 NE19 NE23 PA11Z PA14Z PB00Z PE08Z PF00Z PF03Z PG02Z

Claims (8)

[Claims] 1. A throttle valve provided to be rotatable in both a positive opening side and a negative opening side through a fully closed position that minimizes an intake air amount, and to drive the throttle valve. Throttle actuator
Control means for controlling the throttle actuator so that the opening of the throttle valve matches a target throttle opening set in accordance with an accelerator operation amount or the like, wherein the throttle valve is fully closed when the internal combustion engine is stopped. In the electronic throttle control device for an internal combustion engine, which passes through the position and holds the throttle valve on the minus opening side, the control means does not allow the throttle valve to pass from the minus opening side to the fully closed position when the internal combustion engine is started. An electronic throttle control device for an internal combustion engine, wherein the opening of the throttle valve is controlled in a movable range on the minus opening side (hereinafter, this control is referred to as "minus opening side control"). 2. The control device according to claim 1, wherein the controller controls the opening of the throttle valve in a movable range on the minus opening side according to the accelerator operation amount during the execution of the minus opening side control. Item 2. An electronic throttle control device for an internal combustion engine according to item 1. 3. The control means drives the throttle valve to the positive opening side temporarily during the execution of the negative opening side control, and performs the normal control when the throttle valve passes the fully closed position. The electronic throttle control device for an internal combustion engine according to claim 1 or 2, wherein the electronic throttle control device returns to (1). 4. The control device according to claim 3, wherein the control means performs the drive to the positive opening side of the throttle valve during the negative opening side control during idling while the vehicle is stopped. Electronic throttle control device for internal combustion engine. 5. The control unit according to claim 3, wherein the throttle valve is driven to a positive opening side at a predetermined interval during the execution of the negative opening side control.
Or an electronic throttle control device for an internal combustion engine according to 4. 6. The control means gradually returns the characteristic of the target throttle opening degree to the accelerator operation amount to a normal state when returning from the minus opening degree control to the normal control. An electronic throttle control device for an internal combustion engine according to any one of claims 3 to 5. 7. The control means gradually increases an upper limit guard value for limiting a maximum positive opening of the throttle valve when returning to the normal control from the negative opening side control. An electronic throttle control device for an internal combustion engine according to any one of claims 3 to 6. 8. The control device according to claim 3, wherein the control unit does not perform the drive to the plus opening side when the execution frequency of the minus opening side control becomes a predetermined frequency or more.
An electronic throttle control device for an internal combustion engine according to any one of claims 1 to 7.