JPS61229949A - Throttle controller for vehicle - Google Patents

Abstract

PURPOSE:To prevent a vehicle from reckless driving by providing a throttle valve driving device capable of transmitting disengageably a drive force between the throttle valve and a motor to close the throttle valve in abnormalities. CONSTITUTION:Between a motor 4 for driving a throttle valve 1 and the throttle vlave 1 is provided a throttle valve driving device 5. When a micro-computer 7 has any abnormalities, pulse voltage is not generated so that a watch dock circuit 11 does not generate voltage and said device 5 stops its operation to close the throttle valve 1. Thus, even when any failures take place in a controller, a vehicle can be prevented from reckless driving leading to danger of accident.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a control device for a throttle valve used for controlling a vehicle engine, and particularly to a fail-safe system thereof.

[Conventional technology]

Conventionally, the throttle valve of an automobile was connected to the accelerator pedal with a wire such as a piano wire, and this was driven in conjunction with the movement of the accelerator pedal to control the engine.

However, in recent years, for example,
As shown in Japanese Patent No. 200856, an idea has been proposed in which the accelerator pedal and the throttle valve are separated and the throttle valve is freely driven by a microcomputer.

By separating the accelerator pedal and the throttle valve drive in this way, various controls become possible. for example,
If the amount of accelerator pedal depression is regarded as the driver's request for vehicle speed, the microcomputer only needs to drive the throttle valve so that the vehicle speed corresponds to the amount of pedal depression. Next, assuming that pressing the accelerator pedal requests engine torque, the throttle is controlled to output a carrot torque corresponding to the amount of pressing the accelerator pedal. Furthermore, various controls such as idle rotation speed control during idle rotation, constant speed running control, and extremely low speed running are possible. In particular, if a stepping motor is used as the motor for driving the throttle valve, fine control is possible and the throttle valve can be driven accurately using digital output from a computer.

[Problem that the invention seeks to solve]

However, in the above-mentioned device, if the computer or drive motor breaks down, the throttle valve may remain open and stop. , the rotation of carrots may become abnormally high and never return to normal. In such a case, there is a risk that the vehicle may run out of control and cause an accident, and there has been a demand for establishing safety against this type of failure.

The present invention was developed in view of the above problems, and an object of the present invention is to provide a highly safe throttle control device for a vehicle that can prevent dangers such as a runaway vehicle.

[Means for solving problems]

A vehicle throttle control device according to the present invention includes a separable throttle valve drive device for transmitting driving force between the throttle valve and the motor, and closes the throttle valve when an abnormality occurs. .

[Effect]

In the vehicle throttle control device of the present invention, the microcomputer detects that the output signal of the rotation angle sensor of the throttle valve and the rotation angle signal of the drive command to the motor differ by more than a predetermined value at the time of runaway and that this continues for a predetermined period of time. In this case, the output signal is stopped, and the watchdog circuit therefore stops the throttle valve drive device, and the system throttle valve, which is in a state where the motor and the throttle valve are separated from each other, is closed.

〔Example〕

FIG. 1 shows the configuration of a vehicle throttle control device according to the present invention. In the figure, 1 is the intake passage 3 of the engine 2.
It is rotatably held by a throttle valve disposed therein, and biased in the closing direction by a spring (not shown). 4
is a motor that drives the throttle valve 1, and a throttle valve driving device 5 is installed between the motor 4 and the throttle valve 1. This throttle valve driving device 5 transmits the driving force of the motor 4 to the throttle valve 1, and disconnects the driving force of the motor 5 in response to a stop signal from a watchdog circuit, which will be described later. 6 is a rotation angle detection sensor that detects the rotation angle (opening degree) of the throttle valve 10, and 7 is a microcomputer to which this output signal is input. The output signal of the accelerator pedal sensor 9 to be detected is inputted through an input peripheral circuit (not shown). The Mayu microcomputer 7 is input with the information necessary to operate the engine 2 and move the car, such as the engine speed and vehicle speed, and the microcomputer 7 uses this input information to control the accelerator pedal. A drive command is output to the motor 4 through the peripheral circuit 10 so as to give a throttle opening corresponding to the depression of step 8. In addition,
The rotation angle detection sensor 6 and the accelerator pedal sensor 9 use a variable resistor, a rotary encoder, or the like.

Furthermore, 11.12 is a watchdog circuit that outputs a voltage when a pulse output is input from the microcomputer 7, and 13 is a logic circuit that takes the logical product of the output signals of these watchdog circuits 11.12. The output is connected to the throttle valve drive device 5.

In the vehicle throttle control device configured as described above, the microcomputer 7 outputs a drive command to the motor 4 based on the amount of depression of the accelerator pedal 8, and the motor 4
The driving force is transmitted to the throttle valve 1 via the throttle valve drive device 5, and the throttle valve 1 is opened and closed by a predetermined amount. When the program is working normally, the microcomputer 7 periodically outputs a pulse voltage to the watchdog circuit 11, and while this output pulse exists, a constant DC voltage is output, so the watchdog circuit 11 also outputs voltage. In addition, this microcomputer 7 periodically sends a pulse voltage to a watchdog circuit 12 when the output signal of the rotation angle detection sensor 6 matches the rotation angle signal that commands the motor 4 to drive based on the accelerator opening degree. This watchdog circuit 12 also outputs a voltage, and therefore a transmission signal is given to the throttle valve drive device 5 to perform normal throttle control. However, if some abnormality occurs in the microcomputer 7 and it goes out of control, the watchdog circuit 11 will not output any voltage because the pulse voltage will not be output.

Therefore, the throttle valve drive device 5 stops its operation and the throttle valve 1 is closed. Further, if the output signal of the nine rotation angle detection sensor 6 and the rotation angle signal to the motor 4 differ significantly and this continues for a predetermined period of time, for example, 10 seconds or more, the microcomputer 7 controls the output signal to the motor 4. Abnormal circuit, abnormal connection to motor 4, rotation angle detection sensor 6
Alternatively, it is determined that some kind of failure has occurred in the device, such as an abnormality in the accelerator pedal sensor 9, and the output to the watchdog circuit 12 is stopped. Therefore, in this case, watchdog circuit 1
2 does not output a signal, the throttle valve driving device 5 stops, and the driving force of the motor 4 is not transmitted to the throttle valve 1.

In this manner, if any abnormality occurs in the control device, the motor 4 and the throttle valve 1 are disconnected, the throttle valve 1 is closed, and there is no risk that the engine 20 rotations will become abnormally high.

FIG. 2 is a perspective view showing one embodiment of the throttle valve driving device 5. As shown in FIG. This throttle valve drive device 5 has a claw 15 that protrudes by applying a current to a solenoid 14 and comes into contact with an arm 16 that drives the throttle valve 1 to drive the motor 4.
When the current to the solenoid 14 is cut off, the claw 15 is retracted and separated from the arm 16, and is urged in the closing direction by a spring (not shown). Throttle valve l
is configured to be closed.

Further, FIG. 3 shows another embodiment of the throttle valve drive device, and this throttle valve drive device 5a has an electromagnet 19 installed on a rotary arm 18 attached to the drive shaft of the motor 4, and an arm 20 of the throttle valve 1. The rotary arm 18 and the arm 20 are separated from each other and transmission of driving force is stopped when the current to the electromagnet 19 is cut off.

Furthermore, FIG. 4 shows a third embodiment of the throttle valve drive device, and this throttle valve drive device 5b transfers the driving force of the motor 4 to a gear 21 on the motor 4 side, a gear 22 on the throttle valve 1 side, and these gears. The gear 23 meshes with the solenoid 21 and 22, and the gear 23 is connected to the solenoid 2.
4, the gear 23 is retractable so that when the current to the solenoid 24 is cut off, the gear 23 is separated from the gears 21 and 22, and the transmission of driving force therebetween is stopped.

FIG. 5 shows a specific circuit of the watchdog circuit. In the figure, a transistor 25 has its base connected to the output of the microcomputer 7 via a resistor 26, and its emitter connected to a power supply and to the output of the microcomputer 7 via a resistor 27.

28 is a comparator whose positive input terminal is connected to the collector of the transistor 25 and grounded via a capacitor 29 and a resistor 30. The negative input terminal of the terminal is connected to the power supply through the resistor 31, and the resistor 3
2, and the output terminal is connected to a power supply via a resistor 33. In such a watchdog circuit, first, an output pulse from the microcomputer 7 passes through the transistor 25 and charges the capacitor 29. Since a part of the charged electric charge is discharged through the resistor 30, the pulse current is determined and unless it is output in a cycle shorter than the next cycle,
It is not possible to charge the capacitor 29 and maintain a constant voltage. This voltage is then compared with a predetermined voltage by a comparator 28, and if a voltage higher than that is maintained, a constant voltage is output, and this output operates the throttle valve drive device. There is.

In the above embodiment, two circuits are provided, the watchdog circuit 11 and the watchdog circuit 120, but a single watchdog circuit having these functions may be used.

FIG. 6 is a flowchart of a program related to the 7A program of the microcomputer 7.

The program runs in a loop at a constant cycle while performing various processes, but if the program returns to a certain position in the loop, the program is set to output a pulse to the output terminal, and the computer is running out of control. Check to see if there are any. This result is output to the watchdog circuit 11. Further, when the difference between the output value of the rotation angle detection sensor 6 of the throttle valve 1 and the rotation angle commanded by the computer exceeds a certain set value K, a timer is activated. Then, for a specified period of time,
For example, if this continues for more than 10 seconds, a flag indicating a failure is set and pulse output to the watchdog circuit 12 is stopped. Note that the above-mentioned timer may be a counter.

〔Effect of the invention〕

As described above, according to the vehicle throttle control device of the present invention, the motor that drives the throttle valve is attached via the throttle valve drive device, and the driving force of the motor is not transmitted to the throttle valve in the event of an abnormality. Even if some kind of failure occurs within the device, it is possible to prevent the risk of the vehicle running out of control and causing an accident.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram showing the configuration of a vehicle throttle control device of the present invention, FIG. 2 is a perspective view showing an embodiment of a throttle valve drive device of the vehicle throttle control device, and FIG. 3 is a perspective view showing another embodiment of the same throttle valve drive device, FIG. 4 is a perspective view showing a third embodiment of the same throttle valve drive device, and FIG. 5 is a vehicle throttle control device of the present invention. FIG. 6 is a circuit diagram showing an embodiment of the watchdog circuit of the present invention, and FIG. 6 is a flowchart showing the operation of the microcomputer of the throttle control device for the vehicle. DESCRIPTION OF SYMBOLS 1... Throttle valve, 2... Engine, 4... Motor, 5°5a, 5b... Throttle valve drive device, 6...
・Rotation angle detection sensor, 7... microcomputer,
8...Accelerator pedal, 9...Accelerator pedal senna, 11°12...Watchdog circuit. In addition, the same reference numerals in the figures indicate the same or equivalent parts O. Agent Masuo Oiwa Figure 1 Figure 2rlA Figure 3 Figure 4 Figure 5

Claims (1)

[Claims] It is installed between the motor and the throttle valve, which is installed in the intake passage of the engine and is biased in the closing direction, and transmits the driving force of the motor to the throttle valve to open and close the throttle valve. A throttle valve drive device capable of stopping force transmission, a rotation angle detection sensor that detects the rotation angle of the throttle valve, an output signal of this rotation angle detection sensor is input, and a drive command is output to the motor based on the accelerator opening degree. and a microcomputer that stops the output signal when the output signal runs out of control and when the output signal of the rotation angle detection sensor and the rotation angle signal of the drive command differ by more than a predetermined value and this continues for a predetermined time; A vehicular throttle control device comprising a watchdog circuit for stopping the throttle valve driving device when the output signal is not inputted.