JPH06264778A - Electronic throttle drive device - Google Patents

Abstract

PURPOSE:To provide an electronic throttle drive device capable of accurately detecting sticking of an electromagnetic clutch for throttle valve opening and closing control. CONSTITUTION:In a state controlled to separate a second electromagnetic clutch 5, voltage is applied to a DC motor 7 in the direction to close a throttle valve 1 from an electromagnetic clutch drive circuit 33d of an electronic controller 33, a motor drive electric current at the time of this voltage application is detected and in accordance with this motor drive electric current, sticking of the second electromagnetic clutch 5 is judged, and in the case when the second electromagnetic clutch 5 is stuck, a warning light is flashed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic throttle drive device for controlling opening / closing of a throttle valve by a motor, and more specifically, opening / closing operation of the throttle valve can be controlled by an accelerator pedal via a first electromagnetic clutch. In addition, the present invention relates to an electronic throttle drive device that can be electronically controlled by a motor via a second electromagnetic clutch.

[0002]

2. Description of the Related Art Electronic throttle drives of this type are
For example, as disclosed in Japanese Patent Application Laid-Open No. 2-30939, a normally closed first electromagnetic clutch that is in a connected state when not energized and a second normally open type electromagnetic clutch that is not connected in a non-energized state. Having a clutch and a first
A throttle valve is connected to one end of the electromagnetic clutch and the second electromagnetic clutch, a motor is arranged at the other end of the second electromagnetic clutch, and an accelerator lever interlocked with an accelerator pedal is arranged at the other end of the first electromagnetic clutch. is doing.

More specifically, an accelerator drum connected to one end of an accelerator wire via a first electromagnetic clutch is provided on one of the rotary shafts of a throttle valve incorporated in a throttle body, and the throttle valve rotates. A motor for opening and closing the throttle valve is provided on the other side of the shaft via a second electromagnetic clutch. When the opening / closing of the throttle valve is electronically controlled by the motor via the second electromagnetic clutch, constant speed traveling control can be performed so as to maintain the vehicle speed at a desired set speed, and When the electronic control is released, by operating the accelerator pedal connected to the other end of the accelerator wire, the operation of the accelerator drum corresponding to the operation of the accelerator pedal is transmitted to the throttle valve via the first electromagnetic clutch to throttle the throttle valve. The valve is controlled to open and close, and the traveling operation is performed according to the operation of the accelerator pedal.

In the electronic throttle drive device constructed as described above, the throttle valve is opened / closed by the motor in the normal state, and the electric current to both electromagnetic clutches is stopped in the abnormal state to stop the opening / closing of the throttle valve by the motor. The throttle valve is opened and closed by the pedal to allow the accelerator pedal to run.

[0005]

In the above-mentioned conventional electronic throttle drive device, when the electromagnetic clutch is de-energized, the second electromagnetic clutch for transmitting the rotation of the motor to the throttle valve is a complete clutch. Although it must be separated from the plate, the electromagnetic clutch may stick to the clutch plate for some reason.

The present invention has been made in view of the above,
It is an object of the invention to provide an electronic throttle drive device capable of accurately detecting sticking of an electromagnetic clutch for throttle valve opening / closing control.

[0007]

In order to achieve the above object, the electronic throttle drive device of the present invention, as shown in FIG. 1, has a motor for controlling the rotation of the throttle valve so that the opening / closing of the throttle valve is electronically controlled by the motor. An electronic throttle drive device having an electromagnetic clutch transmitting to a motor, a voltage for applying a predetermined voltage for controlling rotation of the motor in a direction of closing the throttle valve in a state where the electromagnetic clutch is controlled to be disengaged. Applying means 91, current detecting means 92 for detecting a motor driving current when the voltage is applied to the motor, and sticking judging means for judging sticking of the electromagnetic clutch based on the motor driving current detected by the current detecting means. The point is to have 93 and.

[0008]

In the electronic throttle drive device of the present invention, a voltage is applied to the motor in the direction to close the throttle valve in a state where the electromagnetic clutch is controlled to be disengaged, and the motor drive current at the time of applying the voltage is detected, and the motor is driven. The sticking of the electromagnetic clutch is determined based on the drive current.

[0009]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 2 is a sectional view showing the structure of an electronic throttle driving device according to an embodiment of the present invention. The electronic throttle drive device 10 shown in the figure has a normally open first electromagnetic clutch 3 for transmitting the operation amount of an accelerator pedal to the throttle valve 1 on the left side of the throttle valve 1 and for rotating the DC motor 7. A normally-closed second electromagnetic clutch 5 that transmits to the throttle valve 1 is provided on the right side of the throttle valve 1, and an electronic controller (not shown) opens and closes the throttle valve 1 via the DC motor 7 and the second electromagnetic clutch 5. By performing electronic control, automatic constant speed traveling control (ASCD) can be performed without using the accelerator pedal, and the operation amount of the accelerator pedal can be transmitted to the throttle valve 1 via the first electromagnetic clutch 3. Control of driving force characteristics by accelerator pedal (accelerator-by-wire control ) Can be carried out.

The first electromagnetic clutch 3 has an accelerator drum 13 connected to an accelerator pedal (not shown) through an accelerator wire 11 and a first electromagnetic clutch plate 15 which is brought into contact with and separated from the accelerator drum 13. This first
The electromagnetic clutch plate 15 is biased by a first clutch biasing spring 17 having a spring constant K ₁ . Further, a first electromagnetic clutch coil 19 is provided near the first electromagnetic clutch plate 15, and when the first electromagnetic clutch coil 19 is energized, the first electromagnetic clutch coil 19 is turned on.
When the first electromagnetic clutch plate 15 is attracted by the magnetic force of the electromagnetic clutch coil 19 to separate the first electromagnetic clutch plate 15 from the accelerator drum 13, and the first electromagnetic clutch coil 19 is de-energized,
The first electromagnetic clutch plate 15 causes the accelerator drum 13 to move by the urging force of the first clutch urging spring 17.
It is designed to be connected to.

Further, the first electromagnetic clutch 3 has a throttle valve return spring 9 for urging the throttle valve 1 in the closing direction. Further, an accelerator drum return spring 14 is attached to the accelerator drum 13, and an accelerator sensor 12a and a throttle sensor 12b are provided near its side.

On the other hand, the second electromagnetic clutch 5 has a DC motor 7 whose rotation is controlled by an electronic controller (not shown), and the rotation of the DC motor 7 is transmitted to the clutch connecting plate 23 via the reduction gear 21. It is like this. A second electromagnetic clutch plate 25 is arranged opposite to the clutch coupling plate 23, and the second electromagnetic clutch plate 25 is provided by a second clutch biasing spring 27 having a spring constant K ₂ . It is energized and is normally disconnected from the clutch connecting plate 23. In addition, the second electromagnetic clutch plate 2
5, a second electromagnetic clutch coil 29 is provided on the side opposite to the clutch coupling plate 23, and when the second electromagnetic clutch coil 29 is energized, the magnetic force of the second electromagnetic clutch coil 29 is increased. To pull the clutch connecting plate 23 to the second electromagnetic clutch plate 2
5 and the clutch connecting plate 23 are connected, whereby the rotation of the DC motor 7 is transmitted to the throttle valve 1 via the reduction gear 21, the clutch connecting plate 23, and the second electromagnetic clutch plate 25, and the throttle valve 1 is connected. The opening / closing can be controlled according to the rotation of the DC motor 7. When the second electromagnetic clutch coil 29 is in the non-energized state, the clutch coupling plate 23 is separated from the second electromagnetic clutch plate 25 by the urging force of the second clutch urging spring 27.

FIG. 3 is a system configuration diagram using the electronic throttle drive device 10 shown in FIG. The electronic throttle drive device 10 of FIG. 2 is shown in the right side portion of FIG. 3, and the accelerator drum 13 is the accelerator wire 11.
Is connected to the accelerator pedal 31 via
The C motor 7 is connected to the motor drive circuit 33b of the electronic controller 33 via a pair of cables 32. Further, the first electromagnetic clutch coil 19 and the second electromagnetic clutch coil 29 of the electronic throttle drive device 10 are connected in series, one end of which is connected to the ground, and the other end of which is connected to the electronic controller 33 via the cable 34. It is connected to the electromagnetic clutch drive circuit 33d.

The electronic controller 33 has a microcomputer 33a and a self-holding relay circuit 33c in addition to the motor drive circuit 33b and the electromagnetic clutch drive circuit 33d, and the microcomputer 33a has the accelerator sensor 12a, throttle sensor 12b and vehicle speed sensor. 35,
A cancel switch 37 and a set switch 39 are connected, and a brake limit switch 41 is connected to the self-holding relay circuit 33c.
An accelerator limit switch 43 is connected between 3c and the motor drive circuit 33b.

The accelerator sensor 12a is an accelerator opening sensor (double system), detects the accelerator opening ACC of the accelerator pedal 31 by the output voltage of the potentiometer, and supplies it to the microcomputer 33a. The throttle sensor 12b is a throttle opening sensor, detects the throttle opening TVO of the throttle valve 1 by the output voltage of the potentiometer, and supplies it to the microcomputer 33a. The vehicle speed sensor 35 supplies a pulse signal having a frequency proportional to the vehicle speed to the microcomputer 33a by an electromagnetic pickup or the like provided on the transmission output shaft.

The set switch 39 is an ASCD set switch that indicates the start of automatic constant speed running control (ASCD), and the cancel switch 37 is an automatic constant speed running control (ACD).
It is a cancel switch for ASCD indicating cancellation of (SCD). The brake limit switch 41 is a switch which is closed and turned on only when the brake is not operated, and the accelerator limit switch 43 is a switch which is opened and turned off only when the accelerator is not operated.

The microcomputer 33a is an ordinary one-chip microcomputer, which has a built-in CPU, RAM, ROM, digital port, A / D port, various timers, etc., and outputs a CLUTCH signal for instructing energization of the electromagnetic clutch when the system is normal. A DIR that outputs the target throttle opening based on the output signals of various sensors and the switch signal, and indicates the forward / reverse direction of the DC motor 7 so that the actual throttle opening matches the target value.
It outputs a signal and a DUTY signal instructing the drive current of the DC motor 7. When the system fails, the DC motor 7
A signal for instructing the interruption of the drive current and the clutch drive current is output, and control is performed to shift the throttle control by the DC motor 7 to the throttle direct control by the accelerator pedal 31.

The motor drive circuit 33b is a microcomputer 33a.
The power transistor in the output stage is controlled to be turned on / off based on the DUTY signal and the DIR signal from the control signal to control the drive current and the current direction of the DC motor 7. The self-holding relay circuit 33c turns on when the set switch 39 is pressed, and thereafter keeps on until the cancel switch 37 is pressed, the brake is operated, or the ignition switch is turned off. The electromagnetic clutch drive circuit 33d controls the power transistor on / off based on the CLUTCH signal from the microcomputer 33a, and controls the first electromagnetic clutch coil 19 and the second electromagnetic clutch coil 29.

A warning lamp 51 for notifying the fixation of the second electromagnetic clutch 5 when the fixation of the second electromagnetic clutch 5 is detected is connected to the microcomputer 33a as described later.

Next, the operation of the electronic throttle driving device constructed as described above will be described with reference to the flow charts shown in FIGS. The processing shown in FIGS. 4 and 5 is performed by the microcomputer 33a in a predetermined cycle, for example, 10 mse.
It is carried out for each c.

First, the system is diagnosed based on the signals from the sensors and switches, and the presence or absence of a failure is confirmed (steps P1 and P2). CL for instructing ON / OFF of the electromagnetic clutch drive current when there is a system failure
The values of DUTY and DIR indicating the drive current and rotation direction of the UTCH and DC motor 7 are initialized to 0 (step P3), and the process proceeds to step P13.

When the system is normal, the accelerator opening degree ACC, the throttle opening degree TVO, and the vehicle speed VSP are calculated based on the read values of the respective sensors (steps P4 to P4).
6).

Next, it is checked whether or not the value of the flag Fmode is 1, and the automatic constant speed running control (ASCD) has been executed until now.
It is determined whether or not it is in the middle or in the accelerator-by-wire control (step P7). If the flag Fmode is 1, it is determined whether or not the set switch 39 for instructing the start of the ASCD control is turned on (step P8). If it is turned on, the flag Fmode is set to 0 (step P8). Then, the current vehicle speed VSPO detected by the vehicle speed sensor 35 is stored and set as the target vehicle speed VSPR (step P10).

Then, the target throttle opening TVOR is calculated from the vehicle speed deviation (VSPR-VSPR0) using a control method such as PID control, and the ASCD control calculation is performed (step P11). Then, by further using a control method such as PID control, the throttle opening deviation (TVOR-TV
Based on O), the duty ratio DUTY for instructing the motor drive current and the DIR for instructing the motor rotation direction are calculated (step P12). The calculated DUTY and DIR are written in a predetermined I / O register of the microcomputer 33a, a PWM signal and a 1-bit signal indicating the motor rotation direction are output (step P13), and the process returns to the first process.

In the check in step P8, if the set switch 39 is not turned on, step P8
Proceeding to 17, the target throttle opening TVOR is calculated from the accelerator opening ACC based on a predetermined accelerator opening-throttle opening correspondence map in consideration of the engine and vehicle characteristics (accelerator-by-wire control calculation), and is described above. Go to step P12 and thereafter.

Further, in the check of step P7,
If the flag Fmode is not 1, the process proceeds to step P14 and it is determined whether the cancel switch 37 for instructing the cancellation of the ASCD control is turned on. If the brake switch is not turned on, it is further judged whether or not the brake is stepped on by turning the brake switch on and off (step P1).
5) If the brake is not pressed, the process proceeds to step P11 and thereafter.

When the cancel switch 37 is turned on or the brake is depressed in the checks in steps P14 and P15, the flag F is detected.
Set mode to 1 and proceed to step P17 above,
Performs accelerator-by-wire control calculations.

Next, with reference to the flow chart shown in FIG. 5, a process of determining whether or not the second electromagnetic clutch 5 is fixed will be described.

The electromagnetic clutch sticking determination process shown in FIG. 5 is performed by sensors such as a throttle sensor and an accelerator sensor forming an electronic throttle driving device, relays and switches such as an inhibitor relay, communication lines between units, and the like. Detecting disconnection of signal lines, circuit failure in the electronic controller, etc., disengages the clutch so that the motor drive force cannot be transmitted to the throttle valve, or the ignition switch is turned off. In some cases, it is performed when there is no fault that causes a problem in driving the motor.

The processing shown in FIG. 5 is executed by the microcomputer 33a at a predetermined cycle, for example, 10 msec.

In FIG. 5, first, the electronic controller 3
The microcomputer 33a of No. 3 supplies a DIR signal indicating the direction in which the throttle valve 1 is closed and a DUTY signal indicating a constant duty ratio to the motor drive circuit 33b (step P21). Then, the motor drive current detection circuit detects the motor current, and the detected motor current is stored as I in the memory (step P22). Then, it is determined whether or not the detected and stored motor current is larger than a predetermined value during normal operation (step P23). If it is not larger, there is no problem and the process is terminated. If it is larger than the predetermined value in the normal state, it is diagnosed that the second electromagnetic clutch 5 is stuck and stuck (step P24).

That is, if the electromagnetic clutch is normally disengaged, the load on the motor should be small and the motor drive current should also be small. On the other hand, if the electromagnetic clutch is fixed, the load on the motor is small. Since the motor drive current is large and the motor drive current is also large, the motor drive current is checked, and if it is larger than a predetermined value in the normal state, it is determined that the electromagnetic clutch is stuck.

As described above, when it is diagnosed that the second electromagnetic clutch 5 is stuck, the microcomputer 33a blinks the warning light 51 to notify the driver (step P25). In this case, when the ignition switch is turned on, the power source of the motor drive circuit 33b is shut off, the power supply source to the motor is shut off, and thereby the throttle drive source is shut off.

[0035]

As described above, according to the present invention,
Applying voltage to the motor in the direction to close the throttle valve in the state of controlling to disconnect the electromagnetic clutch,
Since the motor drive current at the time of applying this voltage is detected and the fixation of the electromagnetic clutch is determined based on this motor drive current, the fixation of the electromagnetic clutch can be accurately detected.

[Brief description of drawings]

FIG. 1 is a diagram corresponding to a claim of the present invention.

FIG. 2 is a cross-sectional view showing a configuration of an electronic throttle driving device according to an embodiment of the present invention.

FIG. 3 is a system configuration diagram using the electronic throttle driving device shown in FIG.

FIG. 4 is a flowchart showing the operation of the electronic throttle driving device shown in FIGS.

FIG. 5 is a flowchart showing a process of detecting a stuck state of an electromagnetic clutch in the electronic throttle drive device shown in FIGS.

[Explanation of symbols]

 1 Throttle Valve 3 First Electromagnetic Clutch 5 Second Electromagnetic Clutch 7 DC Motor 9 Throttle Valve Return Spring 17 First Clutch Energizing Spring 19 First Electromagnetic Clutch Coil 27 Second Clutch Energizing Spring 29 Second electromagnetic clutch coil 51 Warning light

Claims (1)

[Claims] 1. An electronic throttle drive device having an electromagnetic clutch for transmitting rotation of a motor to a throttle valve to electronically control opening / closing of a throttle valve by the motor, wherein the electromagnetic clutch is controlled so as to be disengaged. Voltage application means for applying a predetermined voltage to the motor to control the rotation of the motor in the direction of closing the throttle valve, current detection means for detecting a motor drive current when the voltage is applied to the motor, and the current detection means. An electronic throttle driving device, comprising: a sticking determination means for judging whether the electromagnetic clutch is stuck or not, based on the motor drive current detected in 1.