JPH0125056Y2 - - Google Patents

Description

[Detailed description of the invention] This invention uses a microcomputer to automatically control the opening of the throttle valve so that the actual vehicle speed reaches a preset speed without pressing the accelerator pedal. This invention relates to an automobile speed control device.

In typical prior art, the automatic control of the throttle valve is released by executing a microcomputer program in response to a so-called cancel signal generated when a speed-reducing operation such as a brake or clutch is performed. In addition, when the microcomputer performs an operation that does not follow the program and goes out of control, such runaway is detected by executing a program for detecting runaway, and the speed of the microcomputer is automatically controlled. The program is configured to initialize and reset the program to its first step.
In such prior art, each of the programs described above is relatively complex, and it is extremely difficult to reliably detect runaway patterns of various types using the programs.

The purpose of the present invention is to create a vehicle that achieves, with the simplest possible configuration, the automatic control of the throttle valve by the speed control operation of the brake or clutch, etc., and the prevention of runaway of the microcomputer. An object of the present invention is to provide a speed control device.

Referring to FIG. 1, an embodiment of the present invention is shown, in which a spark ignition internal combustion engine 1 is used as a drive source for an automobile.
A throttle valve 3 is provided in the intake path 2 of the engine. The throttle valve 3 is driven by an actuator 5 for automatic control via a link mechanism 4, and is also operated by an accelerator pedal 6. The microcomputer 7 is powered and operated by power from a power supply 8 via a power switch 9 and a line 10. When the vehicle is running with the speed controlled by the operation of the accelerator pedal 6, the microcomputer 7 gives a high level signal to the inverting circuit 11,
Therefore, the low level signal via the amplifier circuit 12 demagnetizes the release valve solenoid 13 included in the actuator 5. Therefore, the valve body 15 of the release valve 14 is displaced away from the valve seat 17 around the fulcrum 50 by the spring force of the spring 16. Therefore, the diaphragm chamber 18 of the actuator 5 is open to the atmosphere via the valve hole 19, and the diaphragm 20 remains biased by the spring 21 accordingly.

When the car is running at a desired actual speed by operating the accelerator pedal 6, when the set switch 22 is operated, the opening degree of the throttle valve 3 is automatically controlled, and the car continues to run at the set speed. More specifically, the microcomputer 7 records the actual vehicle speed of the vehicle when the set switch 22 is operated.
The set vehicle speed is stored in the memory provided in the
A control valve solenoid 26 included in the actuator 5 is duty-controlled via an inversion circuit 23 and an amplification circuit 24. The control valve solenoid 26 is controlled by changing the duty of the excitation current. When the output from the microcomputer 7 to the reversing circuit 23 is at a high level and the control valve solenoid 26 is not excited, the valve element 28 of the control valve 27 is separated from the valve seat 30 by the spring force of the spring 29. Therefore, the diaphragm chamber 18 is open to the atmosphere via the valve hole 31. This control valve 27 is angularly displaceable around a fulcrum 32. When the valve body 28 is separated from the valve seat 30, the other valve body 33 is separated from the valve seat 30.
4, so that the valve hole 35 is isolated from the diaphragm chamber 18. The valve hole 35 communicates with the intake path 2 upstream of the throttle valve 3 and is under negative pressure. When a low level signal is applied to the inverting circuit 23 from the microcomputer 7, the control valve solenoid 26 is energized. Therefore, the control valve 27 is in the state shown in the first diagram, and the valve body 2
8 is seated on the valve seat 30, the valve body 33 is separated from the valve seat 34, and the diaphragm chamber 18 becomes under negative pressure. Due to the negative pressure in the diaphragm chamber 18, the diaphragm 20 is displaced to the right in FIG. The opening degree is controlled.

Even if the vehicle is not running at the set vehicle speed, that is, even if the automatic speed control is cancelled, if the actual vehicle speed is higher than a predetermined vehicle speed, for example, 40 km/hour, the above-mentioned control is performed by operating the resume switch 36. It is possible to return to the set vehicle speed and start driving. Such a set switch 22
The operation of the actuator 5 according to the operation of the resume switch 36 is achieved by the execution of a program by the microcomputer 7.

Microcomputer 7 has reset input terminal 4
has 0. When the reset input terminal 40 becomes low level, the microcomputer 7 is initialized to the first step of the program and enters the reset state. At this time, the inverting circuits 11 and 23
The signal input to is at a high level, so the microcomputer 7 keeps the release valve solenoid 13 and the control valve solenoid 26 demagnetized, and the vehicle can travel by operating the accelerator pedal 6.

A resistor 41 is connected between reset input terminal 40 and line 10. Reset input terminal 4
0 is grounded via a capacitor 42. The reset input terminal 40 is connected to a switch 44 which becomes conductive when a clutch interposed in the transmission means for transmitting power from the internal combustion engine 1 to the wheels is cut off by depressing the clutch pedal, and a switch 44 which is connected when the parking brake is activated. It is grounded to a low level via a switch 45 which is conductive when the voltage is on. In an automobile equipped with a so-called automatic transmission having a torque converter, the switch 44 is configured to conduct when the select lever is in the neutral position. These switches 44 and 45 have a function of being turned on by a speed control operation of the vehicle. A low level signal is applied to the reset input terminal 40 from the line 10 via a switch 46 and an inverting circuit 47. The switch 46 becomes conductive when the brake pedal is depressed and the vehicle is about to stop or has stopped.

Referring to FIG. 2, when power switch 9 is turned on at time t1, the voltage on line 10 becomes high level as shown in FIG. 21. Therefore, the voltage at the reset input terminal 40 changes at time t as shown in FIG.
It increases from 1 as time passes. Immediately after time t1, the reset input terminal 40 of the microcomputer 7 is at a low level due to the action of the capacitor 42, so that it is reset. This allows the microcomputer 7 to execute the program from the first step of the program. Therefore, by operating the set switch 22 and the resume switch 36, a program for automatic speed control is executed.

During execution of this program, if the microcomputer 7 goes out of control, the driver depresses the brake pedal or the clutch pedal, causing the switches 46 and 44 to conduct and the reset input terminal 40 to go low. Then,
The microcomputer 7 is reset. This prevents the microcomputer 7 from running out of control. Further, when the parking brake is applied, the reset input terminal 40 remains at a low level, so that the microcomputer 7 does not run out of control. The program is configured so that when the microcomputer 7 is reset, the set vehicle speed stored in its memory is not cleared. When the power switch 9 is turned off at time t2, the microcomputer 7 is disabled.

In the present invention, when the power is turned on, the microcomputer 7 is energized and the capacitor 42 is charged via the resistor 41, and when the microcomputer 7 is energized and becomes operational. , the reset input terminal 40
is at the same level as the reset signal, that is, for example, at the low level as mentioned above, so that the microcomputer 7 is reset when the power is turned on, and normal operation is achieved. Also, when the microcomputer 7 is reset,
Solenoid 1 of release valve 17 and control valve 27
3 and 26 are demagnetized, thereby reducing the opening degree of the throttle valve 3, so that safe operation is achieved, and in particular, even if the solenoids 13 and 26 are disconnected, deceleration is performed, so it is safe. be.

As described above, according to the present invention, there is provided means for generating a reset signal by at least one speed control operation such as a brake and a clutch;
Since the microcomputer is reset by this reset signal, even if the microcomputer goes out of control, it can be prevented by the driver's operation of the brake and/or clutch. Therefore, a complicated program for detecting runaway as described in connection with the prior art described above becomes unnecessary. Also, since the reset signal is generated by a speed restraint operation such as a brake and/or clutch, the reset signal is generated in response to a cancel signal generated by the speed restraint operation as described in connection with the prior art mentioned above. The present invention does not require complex programming steps to run a program to disable automatic control of the throttle valve. Moreover, the means for generating a reset signal by such a speed suppression operation has a simple structure. As described above, the present invention achieves many excellent effects.

[Brief explanation of drawings]

FIG. 1 is an overall system diagram of an embodiment of the present invention, and FIG. 2 is a waveform diagram for explaining the reset operation of the microcomputer 7 when the power is turned on. DESCRIPTION OF SYMBOLS 1... Internal combustion engine, 2... Intake path, 3... Throttle valve, 5... Actuator, 6... Accelerator pedal, 7... Microcomputer, 8...
Power supply, 13...Release valve solenoid, 14...
...Release valve, 18...Diaphragm chamber, 20...
...Diaphragm, 21...Spring, 26...Solenoid for control valve, 27...Control valve, 40...Reset input terminal, 41...Resistor, 42...Capacitor, 44, 45, 46...Switch, 47... ...Inversion circuit.

Claims (1)

[Claims for Utility Model Registration] Means 44, 45, 46, 47 for generating a reset signal by at least one speed control operation such as a brake or a clutch; 6, a diaphragm 20 which is an actuator and is connected to the throttle valve 3, and which communicates with the atmosphere on one side and forms a diaphragm chamber 18 on the other side; 3 in the closing direction, and the diaphragm chamber 1 is disposed in the diaphragm chamber 18 by demagnetizing the release valve solenoid 13.
8 to the atmosphere; and a control valve 27 provided in the diaphragm chamber 18 that connects the diaphragm chamber 18 to a negative pressure source by energizing the control valve solenoid 26 and opens it to the atmosphere by demagnetizing the diaphragm chamber 18. Such an actuator 5 comprising
Based on the program, release valve solenoid 1 is activated so that the actual vehicle speed becomes the preset vehicle speed.
The control valve solenoid 26 is duty-controlled while the solenoid 3 remains energized, and the reset signal is received at the reset input terminal 40 to demagnetize the control valve solenoid 26 and the release valve solenoid 13, and the program returns to the first step. A microcomputer 7 to be initialized and a power supply 8 to energize the microcomputer 7
and a capacitor 42 whose one end is connected to the reset input terminal 40 and whose other end is connected to one terminal of the power supply 8 which is at the same level as the reset signal; A speed control device for an automobile, characterized in that a resistor 41 is connected to the other terminal of a power source 8.