JPH07180570A - Throttle valve control device - Google Patents

Abstract

PURPOSE:To exhibit a fail safe function when a failure occurs in an electronic control throttle system and thereafter to perform safe self-running of an automobile. CONSTITUTION:During ordinary operation, a manual system throttle valve 4 is held in a fully opened state through a link 24 and a diaphragm 9. An acceleration wire 12 is slackened loosely enough to prevent the occurrence of interlocking between an accelerator pedal 6 and a throttle valve 4 and the opening of an electronic control system throttle valve 5 is controlled by means of a throttle opening signal determined based on a signal for an accelerator depressing amount. When a failure occurs in an electronic control system, the manual system throttle valve 4 is forcibly closed by using the link 24 and the diaphragm 9. Thereafter, the diaphragm 9 is coupled to the throttle valve 5 through a second link 26. An acceleration wire 12 is released from slacking and the throttle valve 5 is forcibly held in a fully closed state. By depressing the accelerator pedal 6, the opening of the throttle valve 4 is manually controlled.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a throttle valve control device for electronically controlling the opening of a throttle valve of an engine.

[0002]

2. Description of the Related Art In recent years, in the field of automobiles, electronic control of engine control has been used to control the opening of a throttle valve of an engine intake system.

This type of throttle valve control system detects the amount of depression of the accelerator pedal (accelerator position), and a microcomputer (engine control unit) presets an optimum throttle opening according to the amount of depression of the pedal. Is used to control the opening of the throttle valve by driving the throttle actuator based on this opening signal.High-precision control of the throttle opening is possible, improving fuel consumption and exhaust gas purification. It is expected that cruise control (constant vehicle speed control) will be possible as well as the above.

However, in the case of practical application, it is necessary to take the following measures. That is, in this type of electronically controlled throttle system, for example, if the throttle electronic control system such as the throttle actuator or the throttle actuator drive circuit fails and the throttle valve is left open, the throttle valve controls the intake air amount. Since it determines the engine output, it may lead to engine runaway. Therefore, it is necessary to take fail-safe measures. Therefore, for example, as disclosed in Japanese Patent Laid-Open No. 60-50235, a fail-safe throttle valve with a return spring interlocking with an accelerator pedal is provided in addition to a throttle valve electronically controlled by a throttle actuator. Even if the control throttle valve is locked with the throttle valve open, it is possible to prevent the engine from running out of control by releasing the accelerator pedal to close the failsafe throttle valve with the force of the return spring spring.

As a conventional example of this type of throttle valve control device, for example, Japanese Patent Laid-Open No. 61-286 can be used.
There is one disclosed in Japanese Patent No. 547, etc.

[0006]

As described above, this type of throttle control device is provided with safety measures when a failure occurs in the throttle valve drive mechanism (electronic control system) such as the throttle actuator and the throttle actuator drive circuit. , Measures such as emergency closing of the failsafe throttle valve in conjunction with the accelerator pedal and the return spring are proposed, but as other emergency measures,
Even if the throttle valve drive mechanism fails, it would be convenient if the car could be driven by itself and traveled to home or a car repair shop. However, no consideration was given to this point.

The present invention has been made in view of the above points, and an object of the present invention is to provide a fail-safe function when a failure occurs in the throttle valve drive mechanism and to provide emergency measures after that. As a countermeasure, it is to provide a throttle valve control device that enables safe self-driving of an automobile.

[0008]

The gist of the present invention will be described with reference to the reference numerals of the embodiment of FIG.
In addition, an electronic control system throttle valve 5 used in normal operation and a manual system throttle valve 4 used in an emergency are provided in a two-stage arrangement structure in the flow direction, and the electronic control system throttle valve 5 has at least a control unit 14. The opening is controlled via the throttle actuator 18 based on the optimum opening signal calculated by inputting the accelerator pedal depression amount detection signal, and the electronic control system throttle valve 5 and the manual system throttle valve 4 are respectively linked by the link mechanism 2
The throttle opening / closing and holding mechanism 9 is switchably connected to the throttle actuator 18 and the manual type accelerator wire 12 and another throttle opening / closing holding mechanism 9 via 4, 26.
Link mechanism on the manual throttle valve 4 side (hereinafter, this link mechanism is referred to as a first link mechanism 24)
And the manual system throttle valve 4 is held in the fully opened state via the first link mechanism 24, and at the time of this holding operation, the first link mechanism 24 connects the accelerator wire 12 to the accelerator wire 12. The pedal 6 and the manual throttle valve 4 are set so as to move to a position where the pedal 6 and the manual throttle valve 4 are loosened to the extent that they do not work together. Further, the throttle opening / closing holding mechanism 9 has a malfunction in the control system of the electronic control system throttle valve 4. In an emergency, a fail-safe operation for forcibly closing the manual throttle valve 4 via the first link mechanism 24 is performed, and after the fail-safe operation, the electronic mode is changed by the driver or a failure signal of the electronic control system. Link mechanism on the control system side (hereinafter,
This link mechanism is referred to as a second link mechanism 26], and the first link mechanism 24 and the manual throttle valve 4 are released from the connection and the accelerator wire 12 is released from the looseness. The electronically controlled throttle valve 5 is forcibly held in the fully open state via the second link mechanism 26.

[0009]

With this structure, during normal operation,
The electronic control system throttle valve 5 is in the use mode, and at this time, the manual system throttle valve 4 is held in the fully open state via the first link mechanism 24 and the throttle opening / closing holding mechanism 9, and the manual system accelerator wire 12
Is in a slackened state in which the accelerator pedal 6 and the manual throttle valve 4 are not interlocked. Therefore, even if the accelerator pedal 6 is depressed, the manual throttle valve 4 does not operate via the accelerator wire 12, and the manual throttle valve 4 is kept in the fully open state, so that the electronic throttle control operation is guaranteed. That is, the control unit 14 calculates the optimum throttle opening based on the accelerator pedal depression amount detection signal, the cruise control signal, etc., and the throttle actuator 18
The throttle opening of the electronic control system throttle valve 5 is controlled through the control of the intake air amount of the engine.

When the drive mechanism of the throttle electronic control system (throttle actuator 18, throttle actuator drive circuit 14, etc.) fails, first, the first link mechanism 24 and the throttle opening / closing holding mechanism 9 are provided for fail-safe operation. The manual throttle valve 4 is forcibly closed by using the engine so that the engine intake passage becomes the minimum opening degree and the intake amount is controlled to the minimum flow rate. The engine intake air amount determines the fuel amount, and by controlling the intake air amount to the minimum, the engine is fixed in, for example, an idle state, and it is possible to prevent the engine from running out of control.

Further, after the fail-safe operation, it becomes possible to select the use of the manual throttle valve 4 based on the driver's mode switching or the electronic control system failure signal.
When this is selected, the first link mechanism 2 between the throttle opening / closing holding mechanism 9 and the manual throttle valve 4
The connection via 4 is released (the fully open holding operation of the manual throttle valve 4 is released), and the slack of the accelerator wire 12 is released. At this time, the throttle opening / closing holding mechanism 9 is connected to the electronic control system throttle valve 5 via the second link mechanism 26, and the throttle opening / closing holding mechanism 9 forcibly brings the electronic control system throttle valve 5 into the fully opened state. Retained.

As a result, the fail safe is released, and when the accelerator pedal 6 is stepped on, the throttle valve 4 can be manually opened through the accelerator wire 12 to control the intake amount, so that the emergency of the automobile can be performed. Manual self-supporting becomes possible.

In the case of electronic throttle control, the link mechanism 26 is separated from the electronic control system throttle valve 5, and in the case of manual self-driving, the link mechanism 24 is separated from the manual system throttle valve 4. However, since the link mechanism does not burden the opening control of the throttle valves 4 and 5, the load of the driving force required for the operation of the electronic control system or the manual system is reduced.

[0014]

An embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is an overall configuration diagram of a throttle valve control apparatus according to this embodiment. In the figure, 1 is an intake passage of an engine, 2 is an engine, and 3 is a fuel injection valve.

In the intake passage 1, there are a total of 2 upstream and 2 downstream.
The individual throttle valves 4 and 5 are arranged to form a two-stage throttle valve arrangement structure.

The downstream throttle valve 5 serves as an electronic control system throttle valve used during normal operation (throttle electronic control mode), and the upstream throttle valve 5 also serves as a fail-safe when the electronic control system fails (emergency). It becomes a manual throttle valve for self-driving.

The electronic control system throttle valve 5 and the manual system throttle valve 4 are connected to the throttle actuator 18 and the manual system accelerator wire 12 via link mechanisms 24 and 26, respectively, and a separate throttle opening / closing holding mechanism (here, a diaphragm mechanism is used). (Used) 9 is switchably connected via a later-described electromagnetic solenoid type link engagement switching pin 23a.

One end of the first link mechanism 24 is connected to a throttle lever 4a axially attached to a manual throttle valve 4, and this throttle lever 4a also forms a part of the link mechanism 24 and the throttle lever 4a. Is connected via an accelerator pedal 5 and an accelerator wire 12. On the other hand, one end of the second link mechanism 26 is coupled to the lever 5a axially attached to the electronic control system throttle valve 5, and this lever 5a also forms a part of the link mechanism 26.

Between the first and second link mechanisms 24 and 26, there is provided an electromagnetic solenoid type link engagement switching pin 23a for switching and selecting one of these link mechanisms by an electric signal. The link engagement switching pin 23a is connected to the diaphragm mechanism (throttle opening / closing holding mechanism) 9.

In the throttle electronic control mode, the first link (hereinafter simply referred to as "link") 24 and the diaphragm mechanism 9 are connected via the link engagement switching pin 23a, and the diaphragm mechanism 9 is throttled in the engine intake passage 1. Negative pressure downstream of the valve is introduced via the pressure regulator 8 so that the first link 24 causes the manual throttle valve 4 to operate.
Operates so that it is fully opened.

When a failure occurs in the throttle electronic control system, the atmosphere is introduced into the diaphragm mechanism 9 so that the first link 24 operates so as to close the manual system throttle valve 4, and thereafter the link engagement switching pin 23a is electronically operated. The second link 26 and the diaphragm mechanism 9 are connected by switching operation based on a control system failure signal (which may be a mode switching operation by the driver), and the diaphragm mechanism 9 is connected to the negative valve downstream of the throttle valve in the engine intake passage 1. The pressure is introduced and the second link 26
Is set to fully open the electronic control system throttle valve 5.

That is, during normal operation, the manual throttle valve 4 is previously kept fully open through the operations of the solenoid valve 7, the pressure regulator 8, the diaphragm mechanism 9, and the first link 24, which will be described later, and in this state, the accelerator is released. In response to a depression amount detection signal of the pedal 6, an electronic control system throttle valve 5 is provided with a throttle valve electronic control system including an accelerator opening sensor 13, a control unit 14, a throttle actuator drive circuit (control circuit) 17 and a throttle actuator 18. The opening degree is controlled.

Further, in the cruise control (constant vehicle speed control) mode during normal operation, the vehicle speed sensor signal, the control unit 14, the throttle actuator drive circuit 17, and the throttle actuator 18 throttle are provided so that the set vehicle speed can be obtained. The opening of the throttle valve 5 is controlled via the electronic control system. Also in this case, the manual throttle valve 4 is held in the fully opened state via the diaphragm mechanism 9 and the first link 24.

Here, the electronic throttle control system will be described.

The accelerator opening sensor 13 detects the depression amount of the accelerator pedal 6. Control unit 14
Determines the fuel supply amount based on the accelerator pedal depression amount detection value, drives the injection valve 3 via the injection valve control circuit 15, and obtains the air amount commensurate with the fuel supply amount and determines the air amount. The throttle valve opening degree corresponding to the above is calculated, and the throttle actuator 1
Drive eight. Then, the throttle opening state at that time is detected by the throttle opening sensor 19, the actual air amount is detected by the air flow rate sensor 16, and these detected values are fed back to the control unit 14 to obtain an accurate required air amount. The throttle opening corresponding to the above is calculated, and the throttle valve opening control is performed via the throttle actuator drive circuit 17 and the throttle actuator 18. The throttle actuator 18 is composed of, for example, a stepping motor.

On the other hand, the manual throttle valve 4 is the throttle actuator 1 of the electronic control throttle valve 5.
8. When the throttle valve drive mechanism such as the actuator drive circuit 17 fails, the valve 4 itself closes to the minimum opening (opening in the idle rotation range) to prevent runaway of the engine.
After that, it is used as a throttle valve when manually driving by itself. In order to perform the manual operation of the throttle valve, the operating lever 4a of the manual throttle valve 4 and the accelerator pedal 6 are connected via an accelerator wire 10. The wire 10 is used for the diaphragm mechanism 9 in the throttle electronic control mode.
Also, the operation of the link 24 causes slack, and manual control is not performed. This point will be described later.

The solenoid valve 7 has one end connected downstream of the electronic control system throttle valve 5 via a negative pressure introduction passage 10 and the other end connected upstream of the manual system throttle valve 4 via an atmospheric pressure introduction passage 11. And solenoid valve 7
The suction negative pressure or the atmospheric pressure is introduced into the diaphragm mechanism 9 by the switching control.

The diaphragm mechanism 9 operates via the pressure regulator 8 based on the introduction of the suction negative pressure and the atmospheric pressure.

FIG. 2 is a vertical sectional view showing details of the diaphragm mechanism 9. The diaphragm mechanism 9 is composed of a diaphragm 20, a return spring 21, a rod 22 and the like. One end of the rod 22 is connected to the diaphragm 20 and the other end is
An electromagnetic solenoid 23 and a link engagement switching pin 23a that moves by turning on and off the electromagnetic solenoid 23 are incorporated.

In the electromagnetic solenoid type link engagement switching pin 23a, the pin 23a engages with the hole 25 of the link 24 of the manual throttle valve 4 when the electronic solenoid 23 is turned on during normal operation. The manual throttle valve 4 and the diaphragm mechanism 9 are connected via the first link 24. In addition, after the failure of the throttle valve electronic control system, the electromagnetic solenoid 23 is turned off and the pin 23a is moved after the fail-safe operation described later, and the second
Engages with the hole 27 of the link 26, thereby connecting the electronic control system throttle valve 5 and the diaphragm mechanism 9 via the second link 26.

In the diaphragm mechanism 9, when the first and second links 24 and 26 are engaged with the pin 23a, a cover 28 and a cover 29 are provided to restrict the surroundings so that the engaged state does not come off. It is installed in. Further, the pin engaging hole 27 of the link 26 on the electronic control system throttle side is
Even if the electronic control system throttle valve 5 stops at any position from fully closed to fully open due to a failure, it is formed in a long hole shape with a sufficient margin so that the pin 23a can always be inserted.

Next, the operation of this embodiment will be described.

First, regarding normal operation, in this mode, an ON signal is output from the control unit 14 to the electromagnetic solenoid 23 in advance, and the pin 23a is engaged with the first link 24.

In this state, when the engine is started, the solenoid valve 7 is turned on, the suction negative pressure passing through the negative pressure introducing passage 10 acts on the control chamber 9a via the pressure regulator 8, and the diaphragm 20 operates in the direction of arrow A. To do. At that time, the electromagnetic solenoid 2 attached to the diaphragm 20
Since the pin 23a of No. 3 is connected to the first link 24, the throttle lever 4a is pulled in the direction of arrow A through the link 24 as shown in FIG. At the same time, the throttle wire 12 is loosened. Further, the electronic control system throttle valve 5 has electronic control system elements 14, 17, 1
The opening degree is controlled via 8 to reach the idle rotation range opening degree. Then, under this state, fuel control corresponding to idle rotation is performed, and proper idle rotation control is performed.

Next, when the running mode shifts to normal operation, the pin 23a is engaged with the first link 24 in this case as well,
Further, the diaphragm 20 of the diaphragm mechanism 9 is directed in the direction of arrow A, and the manual throttle valve 4 is continuously held in the fully opened state. In this state, the accelerator pedal 1
The depression amount of 3 is detected by the accelerator opening sensor 13 and input to the control unit 14. The control unit 14 first determines the fuel supply amount according to the detection signal, and drives the injection valve 3 via the injection valve control circuit 15. After that, an air amount corresponding to the fuel supply amount is determined, a throttle opening corresponding to the air amount is determined, and the throttle actuator 18 is driven via the throttle actuator control circuit 17 based on this opening signal. Then, the throttle opening at that time is measured by the throttle opening sensor 1
The air flow sensor 1 detects the actual amount of air
6 and feeds back these detection signals to the control unit 14 to obtain the throttle opening corresponding to the required air amount for operation.

Further, when the cruise control is set from the above-mentioned normal operation traveling state, it is performed as shown in FIG.

FIG. 5 is a cruise control (constant vehicle speed control) system diagram during normal operation. As described above, the manual throttle valve 4 is held fully open via the diaphragm mechanism 9 and the link 24. When the driver depresses the accelerator pedal 6 to the vehicle speed intended by the driver, the sensor 13 detects the vehicle speed and inputs it to the control unit 14 and simultaneously inputs the cruise control switch. When the control unit 14 inputs the cruise control switch signal, the control unit 14 sets the vehicle speed at that time as the required vehicle speed, sets the reference throttle opening corresponding to this vehicle speed, and detects the actual traveling vehicle speed. The opening degree of the electronic control system throttle valve 5 is controlled via the throttle actuator drive circuit 17 and the throttle actuator 18 so that the vehicle speed becomes the set vehicle speed.

In the normal driving (throttle valve electronic control) mode, since the wire 12 connecting the accelerator pedal 6 and the upstream throttle lever 4 is slack, the accelerator pedal 6 and the upstream throttle lever 4 are slackened. 4 is not interlocked via the wire 12.

Next, a case where a failure occurs in the throttle actuator drive circuit 17, the throttle actuator 18, etc. of the throttle valve opening electronic control system will be described.

First, when a failure occurs in an element of the throttle valve opening electronic control system, the failure determining means incorporated in the control unit 14 detects the failure state as follows.

FIG. 6A is a flow chart when a failure occurs in the electronic control of the throttle valve opening. To determine such a failure, the actual opening signal .theta. Of the throttle opening sensor after the feedback control and the calculated value .theta. 'In the control unit are read, and if the difference is 0, proper throttle control is performed. And returns to the main routine. If it is not 0, it is determined that the throttle control has a failure, and the routine proceeds to the diaphragm stop routine.

FIG. 6 (b) shows the diaphragm stop routine. If any of the throttle valve drive mechanisms 17 and 18 fails, the control unit 14 is operated first.
Outputs an OFF signal to the solenoid valve 7 to cut the suction negative pressure, and the control chamber 9a of the diaphragm mechanism 9 is set to the atmospheric pressure state, and the negative pressure suction state of the diaphragm 20, the rod 22, and the first link 24 is released. Then, the state of FIG. 3A is returned to the state of FIG. By performing such an operation, the manual throttle valve 4 closes to the idle rotation range.

By closing the manual throttle valve 4 in this way, when the throttle actuator 18 or the throttle actuator drive circuit 17 fails, the runaway of the engine is prevented even if the electronic control throttle valve 5 is left open. Can be prevented.

Further, in this embodiment, after a failure of the throttle valve drive mechanism, the vehicle can be manually driven as follows.

When this manual control is performed, an off signal is output from the control unit 14 to the electromagnetic solenoid 23 in the diaphragm mechanism 9, and the pin 23a of the electromagnetic solenoid 23 is connected to the second link 26 side.
The solenoid valve 7 is turned on again to move the diaphragm 20 to the arrow A side to fully open the electronic control system throttle valve 5. By this operation, the manual throttle valve 4
Is released from the constraint from the first link 24,
The throttle wire 12 is stretched, and the manual throttle valve 4 is interlocked with the accelerator pedal 13 so that the throttle valve drive mechanism can be operated by manual drive, and self-driving is possible after the failure of the throttle valve drive mechanism. When the throttle valve drive mechanism fails, an indication to that effect is given via the display means 45.

FIGS. 4A to 4D are cross-sectional views showing a specific mode of the state immediately before the shift to the manual drive mode after the failure of the throttle electronic control system such as the throttle actuator.

FIG. 4A shows an electronic control system throttle valve 5
However, it failed at the position from fully closed to the idle speed range opening,
This is the state when stopped. Further, FIG. 4B shows a state in which the electronic control system throttle valve 5 fails and stops at a position from the opening in the idle rotation range to the opening before full opening, and FIG. This is a state in which the control system throttle valve 5 fails at the fully open position and is stopped.

In these states, if the state shown in FIG. 4 (a) is left, no matter how much the manual throttle valve 4 is opened, only the amount of air in the idle rotation range will flow, making it impossible to drive by itself. In the state of FIG. 4 (b), the electronic control system throttle valve 5 obstructs the air flow, so that the manual system throttle valve 4 cannot operate as intended by the driver, and FIG. 4 (c) 4 (a),
In the state including (b), that is, when the electronic control system throttle valve 5 fails and stops at any position, the stopping power of the electronic control system throttle valve 5 is lost by the power supply to the throttle actuator being cut off, and the electronic control system The system throttle valve 5 may be closed by the force of the air flow. However, in this embodiment, when the manual control is performed, the link 26 is moved by the suction operation of the diaphragm mechanism 9.
Moves in the direction of arrow A to change the state of FIGS. 4 (a) to 4 (c) to the state of FIG. 4 (d).
Pull a toward the bottom. Therefore, as shown in FIG. 4D, even if the electronic control system throttle valve 5 is in any position,
The electronic control system throttle valve 5 can be held fully open, and since it also functions as a stopper to maintain this state, the manual system throttle valve 4 can be operated manually, even after a failure of the throttle valve drive mechanism, as intended by the driver. Air amount control is possible.

According to this embodiment, when the throttle actuator for electronically controlling the throttle opening, the actuator drive circuit or the like fails, one of the two throttle valves is urgently closed to the idle opening to prevent the vehicle from running out of control. In addition to exhibiting the fail-safe function, the intake air amount can be controlled by manually driving the throttle valve thereafter, so that the vehicle can be driven by itself.

In the case of electronic throttle control, the link 26 is separated from the electronic control system throttle valve 5, and in the case of manual self-driving, the manual system throttle valve 4 is used.
The link 24 is separated from the link 24, and in any case, the link does not burden the opening control of the throttle valves 4 and 5. Therefore, the load of the driving force required for the operation of the electronic control system or the manual system is reduced. You can

[0052]

As described above, according to the present invention, in a device capable of controlling the electronic opening of a throttle valve, when a failure occurs in the throttle valve drive mechanism, in addition to exhibiting a fail-safe function, After that, as an emergency measure, the manual control of the throttle will bring about the effect of enabling the vehicle to drive by itself. Moreover, the electronic control and the manual self-driving can be performed while reducing the load of the throttle driving force.

[Brief description of drawings]

FIG. 1 is a system configuration diagram showing an embodiment of the present invention.

FIG. 2 is a vertical sectional view of a diaphragm mechanism used in the above embodiment.

3A is an explanatory diagram showing a normal operating state of the first embodiment, and FIG. 3B is an explanatory diagram showing a state at the time of failure.

4A to 4D are explanatory views showing a state immediately before an operation in a throttle valve manual control mode of the above embodiment.

FIG. 5 is a system configuration diagram showing a cruise control state of the above embodiment.

6A and 6B are flow charts showing the operation of the above embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Intake passage, 2 ... Internal combustion engine, 4 ... Failsafe manual throttle valve, 5 ... Electronically controlled throttle valve, 6 ... Accelerator pedal, 9 ... Diaphragm mechanism (throttle valve opening / closing holding mechanism), 12 ... Accelerator Wire, 1
4 ... Control unit, 18 ... Throttle actuator, 23a ... Link engagement switching pin, 24, 26 ... Link mechanism.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location F02D 41/22 310 MH

Claims (2)

[Claims] 1. An engine control intake valve (1) is provided with an electronically controlled throttle valve (5) used during normal operation and a manual throttle valve (4) used in an emergency by a two-stage arrangement structure in the flow direction. The electronic control system throttle valve (5) is controlled in opening degree via a throttle actuator (18) based on an optimum opening degree signal calculated by the control unit (14) receiving at least an accelerator pedal depression amount detection signal. Moreover, the electronic control system throttle valve (5) and the manual system throttle valve (4) are respectively linked by a link mechanism (24,
26) through the throttle actuator (18)
And a throttle wire opening / closing holding mechanism (9) different from the accelerator wire (12) of the manual system, and the throttle opening / closing holding mechanism (9) is connected to the manual throttle valve (4) in the throttle electronic control mode. Side link mechanism (hereinafter, this link mechanism will be referred to as a first link mechanism (24)) and the manual throttle valve (4) will be fully opened via the first link mechanism (24). A holding operation is performed, and at the time of this holding operation, the first link mechanism (24) releases the accelerator wire (12) to such an extent that the accelerator pedal (6) and the manual throttle valve (4) are not interlocked. The throttle opening / closing holding mechanism (9) is set so as to move to any position, and the electronic control system throttle valve (4) has a control system. In the event of a failure, a fail-safe operation is performed in which the manual throttle valve (4) is forcibly closed via the first link mechanism (24), and after the fail-safe operation, the mode switching operation of the driver or the electronic control system In response to a failure signal, the electronic control system side link mechanism [hereinafter, this link mechanism
Of the accelerator wire (12) and the first link mechanism (24) and the manual throttle valve (4) are uncoupled from each other and the accelerator wire (12).
Throttle valve control, wherein the electronic control system throttle valve (5) is forcibly held in the fully opened state via the second link mechanism (26) under the release of the slack. apparatus. 2. The first and second link mechanisms (24, 2)
6), an electromagnetic solenoid type link engagement switching pin (23a) for switching and selecting one of these link mechanisms by an electric signal is provided, and the link engagement switching pin (23a) is used for opening and closing the throttle. In the throttle electronic control mode, the first link mechanism (24) and the diaphragm mechanism (9) are connected to each other via the link engagement switching pin (23a). Then, a negative pressure downstream of the throttle valve in the engine intake passage (1) is introduced into the diaphragm mechanism (9) so that the first link mechanism (24) fully opens the manual throttle valve (4). When the throttle electronic control system is operated and a failure occurs, the atmosphere is introduced into the diaphragm mechanism (9) to cause the first link mechanism (24) to operate. The second system operates by closing the manual throttle valve (4), and then the link engagement switching pin (23a) is switched based on a mode switching operation of the driver or a failure signal of the electronic control system to operate the second link. Mechanism 2
6 and the diaphragm mechanism (9) are coupled to each other, a negative pressure downstream of the throttle valve in the engine intake passage (1) is introduced into the diaphragm mechanism (9), and the second link mechanism (26) causes the electronic mechanism to operate. The throttle valve control device according to claim 1, wherein the control system throttle valve (5) is set so as to be fully opened.