JP2000136734A - Failure judgement method of constant speed traveling device for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform failure judgement in different cases for failure judgement of a transistor in a motor driving circuit for a constant speed traveling device. SOLUTION: When detecting (ST2) no motor current flow during decelerating control (ST1), a clutch is put in a cut condition (ST3) and, if a clutch switch is not turned to OFF, when located at a deceleration side lock position, that a deceleration side driving circuit is in failure is not determined and, if the clutch switch is turned to OFF, that a transistor in the deceleration side driving circuit is in opening failure is judged (ST4) because no motor current flows in spite of an open/close controlled condition. In this way, inconvenience of whether the transistor in the deceleration side driving circuit is in opening failure or not cannot be judged only by the fact that motor current is not detected through a conventional deceleration signal is avoided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for judging a failure of a constant speed traveling device for a vehicle.

[0002]

2. Description of the Related Art Conventionally, in a constant speed traveling apparatus for a vehicle, for example, as described in Japanese Patent Application No. 10-153301 by the same applicant, a motor is used as a drive source and the rotational force of the motor is magnetized. In some cases, a clutch is transmitted to a semicircular sheave as an output member of an actuator via a clutch, and a throttle valve connected to the semicircular sheave via a wire is remotely controlled.

[0003] In such a motor-driven actuator, it is necessary to determine the failure of a transistor used in the motor drive circuit. For example, a motor current detection circuit is provided, and each time a forward / reverse drive control signal is output to the motor drive circuit, the presence or absence of the motor current is checked. If the motor current does not flow, the corresponding side of the forward / reverse rotation is detected. It can be determined that the transistor of the motor drive circuit has failed.

[0004]

In the above-described apparatus, when the motor returns to the deceleration-side lock position corresponding to the fully closed position, the motor is prevented from flowing any more. In addition, a limit switch is provided to cut off the motor current. Therefore, if the deceleration-side drive control signal is output while the motor is positioned at the deceleration-side lock position, the limit switch is actuated and the motor current does not flow. Could not be distinguished whether it was malfunctioning or the operation result of the deceleration side lock position detection limit switch.

Conventionally, the combination of the deceleration-side drive control signal and the motor current detection only when it is clear that the throttle valve is on the open side and the limit switch does not operate due to the uncertainty of such a failure judgment. Failure judgment was performed. Therefore, there is a problem that opportunities for making a failure determination are narrowed.

[0006]

SUMMARY OF THE INVENTION In order to solve such a problem and to realize a failure judgment in various situations in a failure judgment of a transistor of a motor drive circuit of a constant-speed traveling device, the present invention According to the invention, there is provided a method for determining a failure of a constant-speed traveling device for a vehicle, in which an actuator having a structure in which a throttle valve is driven by a motor via a clutch performs vehicle speed control to match an actual vehicle speed to a target vehicle speed. A clutch switch for detecting the contact state of the clutch in conjunction with the engagement and disengagement of the clutch;
A step of detecting a motor current when outputting an acceleration / deceleration signal to the motor; and a step of disengaging the clutch if the motor current is not detected when outputting a deceleration signal to the motor. And when the clutch switch detects the disengaged state of the clutch when the motor current is not detected and the clutch is disengaged, determining that the deceleration side drive circuit of the motor has failed. And

According to this, when the motor current is not detected when the deceleration signal is output, it is considered that the transistor of the deceleration-side drive circuit has an open failure. If the clutch switch detects the disengaged state of the clutch, it can be determined that the actuator is in the open / close control position apart from the fully closed position of the throttle valve, and in such a case, the motor current does not flow. If detected, it can be determined that an open failure of the transistor of the deceleration-side drive circuit has occurred.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail with reference to specific examples shown in the accompanying drawings.

FIG. 1 is a schematic diagram showing a schematic configuration of a constant speed traveling device for a vehicle to which the present invention is applied. As shown in FIG. 1, the present constant-speed traveling apparatus uses a motor-driven actuator, and a motor 1 as a drive source thereof.
And a sector gear 2 as a drive side member of a clutch that meshes with a drive gear 1a fixed to the motor drive shaft, and a driven side member of a clutch rotatably and coaxially provided on the sector gear 2. And a semicircular sheave 3. A throttle valve 4 is connected to the semicircular sheave 3 via a wire W.

An exciting coil 5 constituting a magnet clutch is integrally assembled with the sector gear 2, and its magnetic pole surface is oriented in the direction of rotation of the sector gear 2 and the semicircular sheave 3. An armature plate 6 constituting a magnet clutch is integrally assembled with the semicircular sheave 3. become. When the exciting coil 5 and the armature plate 6 are magnetically coupled, the sector gear 2 and the semicircular sheave 3 can rotate integrally with each other.

The motor 1 and the exciting coil 5 are electrically connected to a control circuit 7, and the motor 1 is driven according to the output of the acceleration side drive signal A and the deceleration side drive signal D from the control circuit 7. The excitation coil 5 is excited by the output of the excitation signal CL from the control circuit 7 in the forward and reverse directions. Further, the sector gear 2 is integrally provided with a clutch switch 8 which may be a limit switch for detecting a magnetic coupling (clutch connection) state between the sector gear 2 and the semicircular sheave 3. Is integrally formed with a projection 3a for turning on the clutch switch 8 in the magnetic coupling state.

When the sector gear 2 and the semicircular sheave 3 are engaged by the magnetic coupling between the exciting coil 5 and the armature plate 6, the clutch switch 8 is hit by the projection 3a and the clutch switch 8 is turned on. The ON signal of the clutch switch 8 is input to the control circuit 7, and the control circuit 7 determines whether the clutch is engaged or disengaged according to the input of the clutch signal LS of the clutch switch 8. In the present embodiment, the clutch engagement state is detected by turning on the clutch switch 8 and the clutch disconnection state is detected by turning off the clutch switch 8.

Next, the control circuit 7 will be described below with reference to FIG. The control circuit 7 is provided with a main control unit IC, and the main control unit IC includes a speed sensor SP.
, The set signal from the set switch SW1, the resume signal from the resume switch SW2,
Each is entered.

An excitation signal CL for the excitation coil 5 is sent from the main control unit IC to the actuator ACT.
And the acceleration-side drive signals A1 and A2 and the deceleration-side drive signals D1 and D2 for the motor 1 are output. The acceleration / deceleration-side drive signals A1, A2 and D1, D2 correspond to the transistor Q1.
To Q4, which is output to the bridge circuit 9,
Both transistors Q1 and Q4 that are turned on by the acceleration / deceleration-side drive signals A1 and A2 constitute an acceleration drive circuit, and both transistors Q that are turned on by the deceleration-side drive signals D1 and D2
A deceleration side drive circuit is configured by 2 · Q3.

A switch signal detecting I / O circuit 10 for detecting the on / off state of the clutch switch 8
The detection signal from the I / O circuit 10 is input to the input port LS of the main control unit IC. Further, a current detection circuit 11 for detecting whether or not a drive current is flowing through the motor 1 is connected to the bridge circuit 9, and a motor current detection signal from the current detection circuit 11 is supplied to an input port of the main control unit IC. Input to I.

In the actuator ACT, there is provided a limit switch 12 for detecting the deceleration side lock position of the motor 1 corresponding to the fully closed position of the throttle valve 4. The limit switch 12 is opened when the motor 1 reaches the deceleration side lock position, closed when the motor 1 is rotated from the deceleration side lock position to the fully open side, and the deceleration side drive current can flow to the motor 1 only in the closed state. I have to.

In the control of the constant-speed traveling apparatus thus constructed, a method for judging a transistor failure of the deceleration-side drive circuit in the main control unit IC will be described with reference to the flowchart of FIG. 3 and the time chart of FIG. It is shown below. First, it is determined in a first step ST1 whether or not deceleration control is being performed. If the deceleration control is not being performed, the present control routine is ended. If the deceleration control is being performed, the process proceeds to the second step ST2. In the second step ST2, the presence or absence of the motor current detected by the current detection circuit 11 is determined. If the motor current is flowing, the control routine is terminated, and the deceleration side drive signal is output as shown in FIG. If the motor current cannot be detected in spite of the third step ST3
Proceed to.

When proceeding to the third step ST3, one of the transistors Q2 and Q3 as the deceleration-side drive circuit has an open failure, or the deceleration-side lock position has been reached and the limit switch 12 is opened. It can be either case.

That is, when the valve is in the open state away from the deceleration side lock position, the actuator ACT controls the opening and closing of the throttle valve 4, and in this state, the sector gear 2 and the semicircular sheave 3 are integrated. Then, the clutch switch 8 should be in the ON state. On the other hand, when the actuator ACT is in the deceleration side lock position state,
The return spring of the throttle valve 4 also forcibly pushes the semicircular sheave 3 toward the deceleration lock position. In this state, the semicircular sheave 3 is moved to the sector gear 2 regardless of the excitation / non-excitation state of the excitation coil 5. On the other hand, since the semicircular sheave 3 is joined, the clutch switch 8 is always on.

Therefore, in the third step ST3, the exciting coil 5 is de-energized and the clutch is disconnected, and the next fourth step ST3 is executed.
In step ST4, the state of the clutch switch 8 is determined. If it is determined in the fourth step ST4 that the clutch switch 8 is in the off state (solid line in FIG. 4), the motor current is not detected even though the actuator ACT is located in the opening / closing control region of the throttle valve 4. Therefore, it is determined that a transistor open failure has occurred in the deceleration-side drive circuit, and the process proceeds to a separate failure processing routine.

Conversely, if it is determined in the fourth step ST4 that the clutch switch 8 is in the ON state (the imaginary line in FIG. 4), it can be determined that the actuator ACT is located at the deceleration-side lock position. Limit switch 12
Is in the open state and the deceleration-side drive current cannot flow through the motor 1. In this case, since this is not a circuit failure, the control routine ends, and
The cruise control is continued.

[0022]

As described above, according to the present invention, the engagement / disengagement of the clutch is detected in the actuator in which the motor current does not flow to the deceleration side by the limit switch or the like in the deceleration side lock position corresponding to the fully closed position. The clutch switch detects the clutch disengaged state by the clutch disengagement signal based on the clutch disengagement signal, and determines that the actuator is at the opening / closing control position apart from the fully closed position of the throttle valve, and in such a case, the motor current flows. If no motor current is detected based on the conventional deceleration signal, it is possible to determine whether or not there is an open failure of the transistor of the deceleration-side drive circuit because it is possible to determine that there is no open failure of the transistor of the deceleration-side drive circuit if it detects that there is no open circuit. The inconvenience of being unable to do so can be resolved.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a schematic configuration of a vehicle constant-speed traveling device to which the present invention is applied.

FIG. 2 is a main part control circuit diagram based on the present invention.

FIG. 3 is a control flow diagram based on the present invention.

FIG. 4 is a time chart in control based on the present invention.

[Explanation of symbols]

 Reference Signs List 1 motor, 1a drive gear 2 sector gear 3 semicircular sheave, 3a projection 4 throttle valve 5 excitation coil 6 armature plate 7 control circuit 8 clutch switch 9 bridge circuit 10 I / O circuit 11 current detection circuit 12 limit switch

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Yoshio Morishima 1-2681, Hirosawa-cho, Kiryu-shi, Gunma F-term in Mitsuba Co., Ltd. 3D044 AA33 AE21 3G065 CA20 CA38 DA05 DA06 EA05 KA05 KA12 3G093 AA01 BA00 BA24 DB20 EC02

Claims (1)

[Claims] 1. A method for judging a failure of a constant-speed traveling device for a vehicle, wherein an actuator having a structure in which a throttle valve is driven by a motor via a clutch performs vehicle speed control to match an actual vehicle speed of the vehicle to a target vehicle speed. A clutch switch for detecting whether the clutch is in contact with the clutch in the rotational direction of the motor, and detecting a contact state of the clutch in conjunction with the contact and separation, and outputting an acceleration / deceleration signal to the motor; Detecting a motor current, outputting a deceleration signal to the motor, disengaging the clutch if the motor current is not detected, and disengaging the clutch when the motor current is not detected. If the clutch switch detects the disengaged state of the clutch when the state is disengaged, it is determined that the deceleration-side drive circuit of the motor has failed. Failure judgment method for a vehicle for constant speed running apparatus characterized by having the steps.