JPH112152A - Constant speed running device for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a constant speed running device for a vehicle in which control of forced actuation stop to a clutch means can be performed by a subsidiary CPU in a relatively simple constitution. SOLUTION: A constant speed running device for a vehicle is provided with an actuator 52 to control opening of a throttle valve, and a cruise control means 54 to control actuation of an actuator 52. The actuator 52 includes a motor 56 and a clutch means 58 to rotate the throttle valve, and the cruise control means 54 includes a main CPU 60 to control actuation of the motor 56 and the clutch means 58, and a subsidiary CPU 62 to forcedly stop actuation of the clutch means 58. During constant speed run, a control mode signal is supplied from the main CPU 60 to the subsidiary CPU 62, and the subsidiary CPU 62 controls forced deenergization for the clutch means 58 based on the control mode signal.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicular constant-speed traveling device for driving a vehicle at a constant traveling speed, and in particular, a cruise control means for controlling the traveling of the vehicle comprises a main CPU.
And a constant speed traveling device for a vehicle including two CPUs of a sub CPU.

[0002]

2. Description of the Related Art In recent years, in order to reduce the burden of long-distance traveling of a driver, an apparatus equipped with a constant-speed traveling device that travels a vehicle at a set constant traveling speed has been increasing.
As an example of this constant-speed traveling device, there is one as shown in FIG. Referring to FIG. 6, the conventional constant speed traveling device includes an actuator 2 for controlling the opening of a throttle valve (not shown) and a cruise control means 4 for controlling the operation of the actuator 2. Have. The actuator 2 includes a motor 6 for operating the throttle valve, and clutch means 8 for selectively transmitting the torque from the motor 6 to the throttle valve. The cruise control means 4 includes two CPUs (central processing units), that is, a main CPU 10 and a sub CPU 12. The main CPU 10 controls the operation of the motor 6 and the clutch means 8, and the sub CPU 12 controls the forcible de-energization of the clutch means 8. In connection with the cruise control means 4, a cruise main switch 14, a cruise switch 16 and a cruise release switch 18 are provided. The cruise main switch 14 is a switch for operating the constant speed traveling device, the cruise switch 16 is a switch for setting the traveling speed of the vehicle to start the constant speed traveling, and the cruise release switch 18 is a constant speed driving device. This is a switch for canceling the traveling operation. The cruise control means 4 further includes a vehicle speed sensor 20, and a detection signal from the vehicle speed sensor 20 is sent to the cruise control means 4.

In such a constant speed traveling device, when the cruise main switch 14 is operated, the constant speed traveling device can be driven at a constant speed. When the cruise switch 16 is operated in such a state, the running speed at the time when the cruise switch 16 is operated is stored, and the constant speed running is started with the stored running speed. In the constant-speed running state, the clutch means 8 is operated by a signal from the main CPU 10, and the operation of the motor 6 is controlled by this signal. That is, the traveling speed of the vehicle is slower (or faster) than the set (stored) traveling speed.
Then, the main CPU 10 of the cruise control means 4 operates the motor 6 so that the opening degree of the throttle valve becomes large (or small), and by operating the motor 6 in this manner, the vehicle is kept at a set speed. It is run at high speed. The sub CPU 12 generates a clutch release signal when the running speed of the vehicle becomes abnormally high or low in the constant speed running state, stops the energization of the clutch means 8, and sets the motor 6.
The control of the throttle valve by is released. When the cruise release switch 18 is operated, the cruise control unit 4 releases the constant speed traveling state.

[0004]

However, the conventional constant speed traveling apparatus has the following problems to be solved. That is, as shown in FIG. 6, the speed signal from the vehicle speed sensor 20 is transmitted to the main CPU 10 and the sub CP
U12, the main CPU 10 and the sub CPU
In both cases, the traveling speed of the vehicle is calculated based on these speed signals, the motor 6 and the clutch means 8 are controlled based on the running speed calculated by the main CPU 10, and the clutch is controlled based on the running speed calculated by the sub CPU 12. Forcibly stopping the operation of the means 8, that is, controlling the deenergization. Therefore, the main CPU 10 and the sub CP
Since the running speed is monitored in U12, there is a problem that a control program for the monitoring is complicated. Further, when trying to diagnose a failure of the main CPU 4, there is a problem that the control program becomes complicated.

SUMMARY OF THE INVENTION An object of the present invention is to provide a constant-speed traveling apparatus for a vehicle which can control the forced de-energization of a clutch means by a sub CPU with a relatively simple configuration.

Another object of the present invention is to provide a vehicular constant-speed traveling apparatus capable of performing a failure diagnosis of a main CPU with a relatively simple configuration.

[0007]

SUMMARY OF THE INVENTION The present invention provides a cruise setting means for setting a running speed of a vehicle constant, an actuator for controlling an opening of a throttle valve during a constant speed running operation, and Cruise control means for controlling the operation of the actuator according to a signal from the setting means, wherein the actuator is provided between the motor and the throttle valve, and a motor for rotating the throttle valve. The cruise control means for controlling the operation of the motor and the clutch means, and the clutch means forcibly removing the clutch means. A constant-speed traveling device for a vehicle including a sub-CPU for energizing the vehicle. A control mode signal is sent to the sub CPU, and the sub CPU controls the forcible de-energization of the clutch means based on the control mode signal from the main CPU. Device.

According to the present invention, the sub CPU
Since the forcible de-energization of the clutch means is controlled based on the control mode signal sent to the PU, there is no need to monitor the traveling speed with the sub-CPU, thereby simplifying the control program in the sub-CPU. it can.

Further, according to the present invention, when a signal from an ignition switch is sent to the cruise control means, and when a signal from the ignition switch is sent to the cruise control means at the time of starting operation of the vehicle, the cruise control means is provided. The means performs a failure diagnosis mode, and when the control mode signal is transmitted from the main CPU to the sub CPU during the failure diagnosis mode, the sub CPU generates an abnormality signal.

According to the present invention, when the ignition key is operated at the start of the operation of the vehicle, the failure diagnosis mode is performed. In this failure diagnosis mode, the main CPU
When the control mode signal is sent from the sub-CPU to the sub-CPU, the control mode signal is transmitted to the sub-C
The sub CPU generates an abnormal signal indicating that the main CPU has failed.

According to the present invention, there is provided a cruise main switch for operating a constant-speed traveling operation by a constant-speed traveling device in connection with the cruise control means. When the cruise control unit is operated and the cruise main switch is operated to terminate the constant speed traveling operation, the cruise control unit performs a failure diagnosis mode. During the failure diagnosis mode, the main CPU sends the sub CPU to the sub CPU. When the control mode signal is sent, the sub CPU generates an abnormal signal.

According to the present invention, when the cruise main switch is operated to end the fixed-side traveling operation, the failure diagnosis mode is executed. When a control mode signal is sent from the main CPU to the sub CPU in the failure diagnosis mode, the control mode signal is sent to the sub CPU even though the operation of the constant speed traveling device is completed. The sub CPU generates an abnormal signal indicating that the main CPU has failed.

Further, according to the present invention, the cruise control means performs a failure diagnosis mode when the cruise setting means is operated at the start of constant speed traveling, and the control mode signal is transmitted from the main CPU to the sub-during the failure diagnosis mode. CPU
, The constant speed traveling control by the cruise control means is permitted.

According to the present invention, when the cruise setting means is operated at the start of the constant speed traveling, the failure diagnosis mode is executed.
When a control mode signal is sent from the main CPU to the sub CPU in the failure diagnosis mode, the main C
This means that the PU is operating normally, so that the constant speed traveling control by the cruise control means is permitted.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of a constant-speed traveling device for a vehicle according to the present invention will be described with reference to the accompanying drawings. FIG. 1 is a block diagram schematically showing an embodiment of a constant-speed traveling device for a vehicle according to the present invention.

In FIG. 1, a constant-speed traveling device shown is a throttle valve (not shown) provided in an intake pipe of an internal combustion engine.
And a cruise control means 54 for controlling the operation of the actuator 52. The actuator 52 includes a motor 56 that controls opening and closing of an intake passage of an intake pipe by rotating a throttle valve, and clutch means 58 disposed between the motor 56 and the throttle valve. Motor 56
Can be composed of a DC motor and a stepping motor. Further, the clutch means 58 can be formed of, for example, an electromagnetic clutch having an engagement claw and an engagement recess which are engaged with each other in a detachable manner. Clutch means 58
Is for selectively transmitting the rotational driving force from the motor 56 to the throttle valve. If the motor 56 is rotated forward (or reverse), for example, when the clutch means 58 is energized and in the driving connection state, the rotational driving force from the motor 56 is transmitted to the throttle valve via the clutch means 58,
Thus, the throttle valve is rotated in an opening direction for opening the intake passage (or a closing direction for closing the intake passage). Note that when the clutch means 58 is deenergized and the driving connection is released, the rotational driving force from the motor 56 is not transmitted to the throttle valve.

The cruise control means 54 includes a main CPU 6
0 and the sub CPU 62. The main and sub CPUs 60 and 62 are constituted by, for example, a central processing unit. In this embodiment, the main CPU 60 is for controlling the operation of the motor 56 and the clutch means 58, and the motor 5 is controlled by a signal from the main CPU 60.
6, forward rotation, reverse rotation and stop are controlled. Also, sub C
The PU 62 controls the forcible de-energization of the clutch means 58. When the clutch means 58 is de-energized by a signal from the sub CPU 62, the drive connection is forcibly released. As described later, the main CPU 60 generates a control mode signal at the time of traveling at a constant speed, and sends the control mode signal to the sub CPU 62. This control mode signal
It includes a constant speed traveling signal indicating that the vehicle is traveling at a constant speed by the constant speed traveling device, a speed signal for monitoring the traveling speed of the vehicle, and the like. The sub CPU 62 has a main CP
A clutch release signal is generated based on the control mode signal from U60, as described later, and the clutch means 58 is forcibly released from the drive connection based on the clutch release signal. In this embodiment, the sub CPU 62 provides the speed range in which the constant speed traveling operation is permitted, that is, the lower limit speed value (for example, 60
km / h) and an upper limit speed value (for example, 120 km / h).
h) is stored, and when the running speed of the vehicle becomes lower than the lower limit speed value or becomes higher than the upper limit speed value, the sub CPU 62 generates the clutch release signal.

In connection with the cruise control means 54, there are provided a cruise main switch 64, a cruise switch 66 constituting cruise setting means, and a cruise release switch 68 constituting cruise release means. The cruise main switch 64 is a switch for permitting the operation of the constant speed traveling device. The cruise permit signal from the switch 64 is sent to the main and sub CPUs 60 and 62 of the cruise control means 54. When the cruise main switch 64 is operated, a cruise permitting signal is sent to the cruise control means 54. When the cruise permitting signal is not sent, the cruise switch 66 is operated to perform the constant speed running by the constant speed running device. There is no. The cruise switch 66 is a switch for setting the traveling speed of the vehicle at a constant speed, and a cruise signal from the cruise switch 66 is sent to the main CPU 60. When the cruise switch 66 is turned on (closed) while the cruise main switch 64 is on, the cruise signal is
The traveling speed when the cruise switch 66 is operated is stored in the main CPU 60 based on the cruise signal, and the constant speed traveling based on the stored traveling speed is started. Cruise release switch 68
Is a switch for releasing the constant speed traveling. A cruise release signal from the cruise release switch 68 is sent to the main CPU 60. Cruise control switch 68
Is turned on (closed) to send a crew step release signal to the main CPU 60, whereby the constant speed traveling by the cruise control means 54 is released. The cruise main switch 64, the cruise switch 66, and the cruise release switch 68 are provided near the driver's seat of the vehicle, for example, in association with the steering wheel.

In this embodiment, there are provided a vehicle speed sensor 70 for detecting the running speed of the vehicle and an ignition switch 72 associated with an ignition key (not shown) operated when starting the vehicle. Signals from the vehicle speed sensor 70 and the ignition switch 72 are also sent to the main CPU 60. The ignition switch 72 is provided on a key cylinder (not shown) of the vehicle. When the ignition key is inserted into the key cylinder, the ignition switch 72 is turned on (closed), generates an operation permission signal, and sends the signal to the main CPU 60.

In connection with the cruise control means 54, a warning lamp 74 is further provided. As will be described later, when the sub CPU 62 generates an abnormal signal, the warning lamp 74 is turned on based on the abnormal signal, thereby notifying the driver that the main CPU 60 has failed.

Next, control by the cruise control means 54 will be described. FIG. 2 shows a flowchart of the control by the cruise control means 54. Referring to FIG. 2 together with FIG. 1, in order to perform constant-speed traveling by the constant-speed traveling device, first, the cruise main switch 64 is operated to be turned on (step S1). Then, the cruise control signal from the cruise main switch 64 is sent to the main CPU 60 of the cruise control means 54, whereby the cruise control means 54 enters the cruise permission state.
Next, the process proceeds to step S2, where it is determined whether a cruise release signal has been input to the main CPU 60. At this time, if the cruise release switch 68 is not operated, no cruise release signal is generated, and therefore, the process proceeds to step S3. On the other hand, when the cruise release switch 68 is operated, the cruise release signal is output from the main CPU.
60, and proceeds from step S2 to step S4. In step S4, the clutch means 58 is held inoperative based on the cruise release signal, the motor 56 is inoperative, and the throttle valve (not shown) is not operated by the constant-speed traveling device.

In step S3, the vehicle speed (the vehicle speed monitored by the detection signal from the vehicle speed sensor 70) is within a predetermined range, that is, the lower limit speed value (for example, 60 k).
m / h) or more and the upper limit speed value (for example, 120
km / h) or less. The upper limit speed value and the lower limit speed value are stored in the sub CPU 62,
The main CPU 60 compares the monitor vehicle speed with the lower limit speed and the upper limit speed. If the monitor speed is within the predetermined range, the constant speed traveling allowable state is maintained and step S
Go to 5. On the other hand, when the monitor vehicle speed is out of the predetermined range, the process proceeds to step S4, and the throttle valve is not operated as described above.

In step S5, it is determined whether or not the cruise switch 66 has been operated, and the above-described constant-speed traveling allowable state is maintained until the cruise switch 66 is operated. Then, when the cruise switch 66 is operated,
The process proceeds from step S5 to step S6, and the traveling speed is set. When the cruise switch 66 is operated, a cruise signal is sent to the main CPU 60 and the vehicle speed sensor 7
The monitored vehicle speed monitored based on the detection signal from 0 is stored in the main CPU 60 as a set speed, and the constant speed traveling based on the set speed is performed (step S).
7). During this constant speed traveling, the main CPU 60
The motor 5 is controlled so that the monitor vehicle speed becomes the set traveling speed.
6 and the clutch means 58 are controlled as described above.

When the constant speed traveling is performed in this manner,
Proceeding to step S8, the main CPU 60
A control mode signal is sent to the sub CPU 62, and a constant speed running signal during constant speed running and a speed signal for monitoring the running speed of the vehicle are sent to the sub CPU 62. Therefore, it is not necessary to calculate the monitor vehicle speed in the sub CPU 62, and the control program of the sub CPU 62 can be simplified.

Then, in step S9, the sub CPU
The deenergization control of the clutch means 58 by 62 is performed. That is, when the monitor vehicle speed corresponding to the speed signal from the main CPU 60 is within the predetermined range, that is, not less than the lower limit speed value and not more than the upper limit speed value, the sub CPU 62 does not generate the clutch release signal. C
The drive connection state of the clutch means 58 is not released by the PU 62. On the other hand, when the monitor vehicle speed is out of the predetermined range, that is, smaller than the lower limit speed value or larger than the upper limit speed value, the sub CPU 62 generates a clutch release signal, and the clutch release signal
8 to be sent. Accordingly, the clutch means 58 is forcibly deenergized by the clutch release signal, the drive connection state is released, the rotational driving force from the motor 56 is not transmitted to the throttle valve, and the operation of the throttle valve by the constant speed traveling device is controlled. Is forcibly stopped. As described above, forcible de-energization of the clutch means 58 can be performed using the control mode signal from the main CPU 60.

In such a constant speed traveling apparatus, the failure of the main CPU 60 can be diagnosed by using the control mode signal sent from the main CPU 60 to the sub CPU 62. FIG. 3 shows one control for diagnosing a failure of the main CPU 60. This control is performed at the time of starting operation of the vehicle.

Referring to FIG. 3, at the time of starting operation of the vehicle, first, when an ignition key (not shown) is inserted into a key cylinder (not shown), an ignition switch (not shown) is turned on, and the ignition switch is turned on. 7
2 is sent to the main CPU 60 of the cruise control means 54 (step S11), whereby the failure diagnosis mode by the cruise control means 54 is performed as follows.

In step S12, first, the main C
It is determined whether PU 60 has generated a control mode signal. At this time, if the control mode signal is generated, it means that the control mode signal is generated even though the cruise main switch 64 and the cruise switch 66 are not operated, so that some trouble occurs in the main CPU 60. Will be. Therefore, when a control mode signal is sent from the main CPU 60 to the sub CPU 62 in the failure diagnosis mode, the process proceeds to step 13, where the sub CPU 62 generates an abnormal signal.

When the sub CPU 62 generates an abnormal signal,
A clutch release signal is generated based on the abnormal signal,
This clutch release signal is sent to the clutch means 58,
The clutch means 58 is forcibly deenergized, and is kept in the drive connection released state (step S14). Also, sub C
An abnormal signal from the PU 62 is sent to the warning lamp 74,
The warning lamp 74 is turned on based on the abnormal signal to notify the driver that the main CPU 60 is out of order. As described above, when the main CPU 60 is out of order, the clutch means 58 is forcibly released from the drive connection state, and the throttle valve is not operated by the constant speed traveling device.

If the control mode signal is not generated in step S12, the process proceeds to step S16, and the normal control mode is performed. That is, when the cruise main switch 64 is turned on to perform the constant speed driving,
The process proceeds to step S1 in the flowchart shown in FIG. 2, and thereafter control according to this flowchart is performed as described above.

FIG. 4 shows another control for diagnosing a failure of the main CPU 60. This control is performed when the constant-speed running operation is completed.

Referring to FIG. 4, in this control, cruise main switch 64 is turned on in step S21 (step S21), and then this switch 64 is turned off (open).
(If the switch 64 is turned off immediately after the cruise main switch 64 is turned on, the cruise main switch 64 is turned on, and after the cruise control means 54 performs a constant speed running, the switch 64 is turned off. (Step S22) and the failure diagnosis mode by the cruise control means 54 is performed as follows.

In step S13, first, the main C
It is determined whether PU 60 has generated a control mode signal. At this time, if the control mode signal is generated, it means that the control mode signal is generated even though the cruise main switch 64 and the cruise switch 66 are not operated, so that some trouble occurs in the main CPU 60. Will be. Therefore, when a control mode signal is sent from the main CPU 60 to the sub CPU 62 in the failure diagnosis mode, the process proceeds to step 24, where the sub CPU 62 generates an abnormal signal.

When the sub CPU 62 generates an abnormal signal,
Similar to the control shown in FIG. 3, a clutch release signal is generated based on this abnormal signal, and the clutch means 58 is forcibly held in the drive connection release state (step S25). Further, an abnormal signal from the sub CPU 62 is sent to the warning lamp 74, and the warning lamp 74 is turned on (step S2).
6). Therefore, when the main CPU 60 is out of order, the clutch means 58 is forcibly brought into the drive disconnection state, and the throttle valve is not operated by the constant speed traveling device.

If no control mode signal is generated in step S23, the process proceeds to step S27, where the main CPU 60 is diagnosed as normal, and the warning lamp 26 and the like are not operated.

FIG. 5 shows still another control for diagnosing a failure of the main CPU 60. In this control, a failure diagnosis mode is performed at the start of constant speed traveling.

Referring to FIG. 5, in this control, the cruise switch 6 is turned on after the cruise main switch 64 is turned on.
When 6 is operated, the process proceeds from step S31 to S32, and the failure diagnosis mode by the cruise control means 54 is executed as follows.

In step S32, first, the main C
It is determined whether PU 60 has generated a control mode signal. At this time, if the control mode signal is not generated, the control mode signal is not generated even though the cruise main switch 64 and the cruise switch 66 are operated, so that some trouble has occurred in the main CPU 60. . Therefore, if the control mode signal is not sent from the main CPU 60 to the sub CPU 62 in the failure diagnosis mode, the process proceeds to step S33, where the sub CPU 62 generates an abnormal signal.

When the sub CPU 62 generates an abnormal signal,
Similar to the control shown in FIG. 3, a clutch release signal is generated based on this abnormal signal, and the clutch means 58 is forcibly held in the drive connection release state (step S34). Further, the abnormal signal from the sub CPU 62 is sent to the warning lamp 74, and the warning lamp 74 is turned on (step S3).
5). Accordingly, when the main CPU 60 is out of order, the clutch means 58 is forcibly brought into the drive disconnection state, and the cruise main switch 64 and the cruise switch 66 are operated to turn on both, so that the throttle is controlled by the constant speed traveling device. No valve is activated.

When the control mode signal is generated in step S32, it means that the main CPU 60 is operating normally. Therefore, the process proceeds to step S36 to be in the controllable mode, and the cruise control means 54
Is performed at a constant speed.

The failure diagnosis control in steps S32 to S36 can be performed, for example, between steps S5 and S6 in the flowchart of FIG. In this embodiment, the failure diagnosis mode is performed when the cruise switch 66 is turned on.
If a resume switch (a switch for resuming constant speed running at the previously set traveling speed after canceling the constant speed traveling) is provided in connection with the Can also be performed.

Although the embodiment of the constant speed traveling device according to the present invention has been described above, the present invention is not limited to such an embodiment, and various modifications and corrections can be made without departing from the scope of the present invention. Is possible.

For example, although three examples have been described as the failure diagnosis modes, any one of these failure diagnosis modes can be applied to the flowchart of FIG. 2 alone or in combination of two or three as appropriate. .

[0044]

According to the first aspect of the present invention, the forced de-energization of the clutch means is controlled based on the control mode signal sent from the main CPU to the sub CPU. There is no need to monitor the traveling speed by the sub CPU, which can simplify the control program in the sub CPU.

According to the second aspect of the present invention, when the ignition key is operated at the time of starting operation of the vehicle, the failure diagnosis mode is performed. When a control mode signal is sent from the main CPU to the sub CPU in the failure diagnosis mode, the control mode signal is sent to the sub CPU even though the constant speed traveling device is not in an operating state. The CPU generates an abnormal signal indicating that the main CPU has failed, and easily outputs the main CPU.
The failure of U can be checked.

According to the third aspect of the present invention, when the cruise main switch is operated to end the constant speed traveling operation, the failure diagnosis mode is executed. When a control mode signal is sent from the main CPU to the sub CPU in the failure diagnosis mode, the control mode signal is sent to the sub CPU even though the operation of the constant speed traveling device is completed. Sub CPU is main C
An abnormal signal is generated assuming that the PU has failed, and the failure of the main CPU can be easily checked.

Further, according to the vehicle constant speed traveling apparatus of the present invention, when the cruise setting means is operated at the time of starting the constant speed traveling, the failure diagnosis mode is executed. Then, when a control mode signal is sent from the main CPU to the sub CPU in this failure diagnosis mode, the main CPU is operating normally, so that constant speed traveling control by the cruise control means is permitted.

[Brief description of the drawings]

FIG. 1 is a block diagram schematically showing an embodiment of a constant speed traveling device for a vehicle according to the present invention.

FIG. 2 is a flowchart showing control by cruise control means in the constant speed traveling device of FIG.

FIG. 3 is a flowchart showing one of the controls by the cruise control means for diagnosing a failure of the main CPU.

FIG. 4 is a flowchart showing another control by the cruise control means for diagnosing a failure of the main CPU.

FIG. 5 is a flowchart showing another control by the cruise control means for diagnosing a failure of the main CPU.

FIG. 6 is a block diagram schematically illustrating an example of a conventional constant-speed traveling device.

[Explanation of symbols]

 2,52 Actuator 4,54 Cruise control means 6,56 Motor 8,58 Clutch means 10,60 Main CPU 12,62 Sub CPU 14,64 Cruise main switch 16,66 Cruise switch 20,70 Vehicle speed sensor

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI F02D 29/02 F02D 29/02 K 301 301C

Claims (4)

[Claims] 1. Cruise setting means for setting a running speed of a vehicle constant, an actuator for controlling an opening of a throttle valve during a constant speed running operation, and said actuator in accordance with a signal from said cruise setting means. Cruise control means for controlling the operation of the throttle valve, the actuator is provided between the motor and the throttle valve for rotating the throttle valve, the driving force from the motor Cruise control means includes a main CPU for controlling operation of the motor and the clutch means, and a sub CPU for forcibly deactivating the clutch means. The constant speed traveling device for a vehicle includes a control mode from the main CPU to the sub CPU during the constant speed traveling operation. And a sub-CPU for controlling the forced de-energization of the clutch means based on the control mode signal from the main CPU. 2. A signal from an ignition switch is sent to the cruise control means, and when a signal from the ignition switch is sent to the cruise control means at the time of starting operation of the vehicle, the cruise control means fails. 2. The sub-CPU according to claim 1, wherein the sub-CPU generates an abnormality signal when the control mode signal is transmitted from the main CPU to the sub-CPU during the failure diagnosis mode. A constant speed traveling device for vehicles. 3. A cruise main switch for operating a constant speed traveling operation by a constant speed traveling device is provided in connection with the cruise control means, and a signal from the cruise main switch is transmitted to the cruise control means. When the cruise control switch is operated and the cruise main switch is operated to terminate the constant speed traveling operation, the cruise control means performs a failure diagnosis mode. During the failure diagnosis mode, the main CPU sends the control mode signal to the sub CPU. Is sent,
3. The constant-speed traveling device for a vehicle according to claim 1, wherein the sub CPU generates an abnormal signal. 4. The cruise control means executes a failure diagnosis mode when the cruise setting means is operated at the start of constant speed traveling, and sends the control mode signal from the main CPU to the sub CPU during the failure diagnosis mode. When paid,
The constant speed traveling device for a vehicle according to any one of claims 1 to 3, wherein constant speed traveling control by the cruise control means is permitted.