JPS6316286B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a constant speed traveling device for an automobile, and more specifically, it includes a vehicle speed detection means for detecting the actual vehicle speed, a memory for storing a set vehicle speed, and outputs from these vehicle speed detection means and the memory. The present invention relates to a constant speed driving device for an automobile, comprising a calculation means for deriving a difference between the two, and which runs at a constant speed so that the actual vehicle speed becomes a set vehicle speed based on the output from the calculation means.

Conventionally, in constant speed driving systems for automobiles that have been able to preset a desired set speed regardless of the actual vehicle speed, a signal representing the actual vehicle speed is applied to one input of a comparator serving as a calculation means, and a signal representing the actual vehicle speed is applied to the other input. A signal obtained from a rotary variable resistor or the like is applied to the controller to control the actual vehicle speed to the set vehicle speed. Such prior art is dangerous because sudden acceleration and deceleration may occur if the rotary variable resistor is moved carelessly.

SUMMARY OF THE INVENTION An object of the present invention is to provide a constant speed vehicle driving device with improved safety.

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram of one embodiment of the present invention. A throttle valve 1 provided in connection with an internal combustion engine of an automobile is connected to an accelerator pedal 3 via a link mechanism 2 and an actuator 4.
is connected to a diaphragm 6 made of a material such as rubber, which defines a working chamber 5. A solenoid valve 7 is connected to the working chamber 5, and when the solenoid valve 7 is excited, a negative pressure source such as an intake manifold communicates with the working chamber 5, and the solenoid valve 7 is demagnetized. The working chamber 5 is thereby communicated with external atmospheric pressure. The solenoid valve 7 is given a duty signal from a processing device 8 realized by a microcomputer or the like. Although the processing device 8 is shown in this embodiment as a block diagram, similar operations may be accomplished by executing a program. A vehicle speed detection circuit 10 that detects the actual vehicle speed of the vehicle body derives a vehicle speed signal having a frequency proportional to the actual vehicle speed onto a line 11. switch 12
has a common contact 13 and individual contacts 14 and 15. Individual contacts 14 are connected to line 11 . An output from a preset vehicle speed setter 16 realized by a variable resistor or the like is given to a pseudo vehicle speed signal generating circuit 17. The pseudo vehicle speed signal generation circuit 17 connects a preset vehicle speed setter 16 to a line 18.
A pseudo vehicle speed signal representing the vehicle speed corresponding to the output from the vehicle is derived. This pseudo vehicle speed signal is a pulse train having a frequency proportional to the vehicle speed. The pseudo vehicle speed signal from line 18 is transmitted to individual contact 15 of switch 12.
given to. The switch 12 connects the common contact 13 to the individual contact 1 when the line 19 is at a low level.
4, and at this time, the pseudo vehicle speed signal generation circuit 17
has been inactivated. When the line 19 becomes high level, the common contact 13 of the switch 12 is switched to the individual contact 15 and becomes conductive, and the pseudo vehicle speed signal generating circuit 17 is activated. switch 1
2 is converted into a voltage by a frequency-to-voltage conversion circuit 20 and sent from a line 21 to a subtractor 22.
is applied to one input of switch 2.
The signal is stored in a memory circuit 24 via a high-speed limiter 25 and a low-speed limiter 26. The switch 23 is conductive when the line 28 is at a high level, and is cut off when the line is at a low level. The stored contents of the memory circuit 24 are applied to the other input of the subtracter 22. The subtracter 22 calculates the difference between the output from the frequency-voltage conversion circuit 20 and the content stored in the storage circuit 24 and provides the difference to the duty control circuit 29 . The duty control circuit 29 applies a duty signal to the electromagnetic valve 7 so that the actual vehicle speed represented by the signal via the line 21 is equal to the set vehicle speed represented by the stored contents of the memory circuit 24, thereby controlling the pressure in the working chamber 5. During acceleration, the absolute value of the negative pressure increases and the opening degree of the throttle valve 1 increases, and during deceleration, the absolute value of the negative pressure decreases and the opening degree of the throttle valve 1 decreases.

When the driver operates the set switch 30 to make it conductive, a high level signal is output to the line 28 via the OR gate 31. Therefore, switch 2
3 conducts. In this way, the actual vehicle speed while traveling can be stored in the memory circuit 24.

In order to preset the set vehicle speed in the memory circuit 24 regardless of the actual vehicle speed, the preset vehicle speed setter 16 and the pseudo vehicle speed signal generating circuit 17 are provided as described above, and the preset switch 32 is also provided.

The high-speed limiter 25 in the discrimination circuit 27 derives a low-level signal when the vehicle speed represented by the signal on the line 21 is less than a predetermined upper limit speed V1, and outputs a high-level signal when the vehicle speed is equal to or higher than the upper limit speed V1. Derive. For example, V1=100Km/h
It may be. The low speed limiter 26 is connected to line 2.
When the vehicle speed represented by the signal 1 is less than the lower limit vehicle speed V2, a low level signal is derived and the lower limit vehicle speed V2
When this is the case, a high level signal is derived.
These high speed limiter 25 and low speed limiter 2
The outputs from 6 are respectively given to NOR gates 33. The output of NOR gate 33 is given to AND gate 34. This AND gate 34 has
An output from preset switch 32 is provided. The output from the set switch 30 is further inverted by an inverting circuit 35 and applied to the AND gate 34. The output from AND gate 34 is
A monostable circuit 36 is provided. This monostable circuit 3
The output from 6 is routed to line 19 and applied to delay circuit 37. The output from delay circuit 37 is given to AND gate 38.
The AND gate 38 is given the output from the NOR gate 33 and also the output from the monostable circuit 36 . The output from AND gate 38 is
It is applied from line 28 to switch 23 via OR gate 31.

A preset vehicle speed setter 16 presets a desired set vehicle speed regardless of the actual vehicle speed. Then, press the preset switch 32. At this time, it is assumed that the vehicle speed indicated by the signal on line 21 is less than the upper limit vehicle speed of the high speed limiter 25 and higher than the lower limit vehicle speed V2 of the low speed limiter 26.
Therefore, the high speed limiter 25 and the low speed limiter 2
The output from 6 is low level and therefore
The output from the NOR gate 33 becomes high level.
Set switch 30 is not operated. Therefore, the output from the AND gate 34 remains at a high level for only the time limit W1 from time t1 to time t2, as shown in FIG. 2. Therefore, the common contact 13 of the switch 12 is switched and conductive to the individual contact 15 for a time limit W1 from time t1 to time t2, as shown in FIG. 2. Therefore, the output from the pseudo vehicle speed signal generation circuit 17 is sent from the switch 12 to the frequency-voltage conversion circuit 20 and converted into a voltage. The delay circuit 37 outputs a signal having the waveform shown in FIG. 2 to the AND gate 38. This delay circuit 37 operates from time t3 to time t at time t3 delayed by time limit W2 from time t1.
It is at a high level only until 4. Therefore
A signal shown in FIG. 2 is derived from the AND gate 38, which causes the switch 23 to switch to the second
As shown in FIG. 5, conduction occurs only from time t3 to time t2. The set vehicle speed corresponding to the signal from the pseudo vehicle speed signal generation circuit 17 converted by the frequency-voltage conversion circuit 20 in this way is not stored in the memory circuit 14, and during the period from time t3 to t2 (=W1-W2), The time is selected to be sufficient for a storage operation to occur in storage circuit 24. After time t2, AND gates 34 and 38
The output of the switch 12 remains at a low level, so that the common contact 13 of the switch 12 returns to conduction to the individual contact 14, and the switch 23 is cut off.
Therefore, by operating the preset switch 32,
After the signal representing the vehicle speed set by the preset vehicle speed setter 16 is stored in the memory circuit 24, the contents stored in the memory circuit 24 will not be changed even if the preset vehicle speed setter 16 is carelessly operated. It never gets put away. Therefore, even if the preset vehicle speed setting device 16 is operated carelessly, the actual vehicle speed will not change, and sudden acceleration and deceleration are prevented, allowing safe driving.

Preset switch 32 and set switch 30
Assume that the preset switch is pressed simultaneously, that is, while the set switch is being operated. In this case, the high level signal from set switch 30 is inverted by inverting circuit 35, and therefore the output of AND gate 34 is kept at low level. Therefore, the set switch 30
The switch 23 is made conductive by the output from the switch 23, and the actual vehicle speed is stored in the memory circuit 24. In this way, the operation by the set switch 30 takes priority and the preset operation by the preset switch 32 is not performed.

In this way, the preset vehicle speed setter 16 is set by the preset switch 32 only when the actual vehicle speed of the running vehicle is less than the upper limit vehicle speed V1 of the high speed limiter 25 and higher than the lower limit vehicle speed V2 of the low speed limiter 26. Therefore, it is possible to store the determined set vehicle speed in the storage circuit 24. When the actual vehicle speed is higher than the upper limit vehicle speed V1 of the high speed limiter 25, or when the actual vehicle speed is the lower limit vehicle speed V of the low speed limiter 26.
When it is less than 2, the output of NOR gate 33 remains at a low level, and therefore the outputs of AND gates 34 and 38 remain at a low level regardless of the operation of preset switch 32. Therefore, the preset operation by the preset switch 32 is not performed.

During the period from time t1 to t2, line 21
A signal representing the set vehicle speed set by the preset vehicle speed setter 16 is derived. At this time, the high speed limiter 25 and the low speed limiter 26
determines the signal on line 21. When the vehicle speed set by the preset vehicle speed setter 26 is less than V1 and higher than the lower limit vehicle speed V2, the output from the NOR gate 33 becomes high level. Therefore, during the period from time t3 to time t2, the switch 23 becomes conductive, and the signal representing the set vehicle speed is stored in the memory circuit 24 by the preset vehicle speed setter 16 as described above. When the vehicle speed set by the preset vehicle speed setting device 16 is equal to or higher than the upper limit vehicle speed V1 or lower than the lower limit vehicle speed V2, the outputs from the high speed limiter 25 and the low speed limiter 26 are at a high level, and therefore the NOR The output of gate 33 becomes low level, and the outputs of AND gates 34 and 38 are forced to low level. In this way, the preset vehicle speed setting device 1 is set by the operation of the preset switch 32.
The signal representing the vehicle speed set in step 6 is not stored in the memory circuit 24. In this way, even if the preset vehicle speed setter 16 and the pseudo vehicle speed signal generation circuit 17 derive a signal representing an abnormal vehicle speed due to a failure or the like, the signal representing the abnormal vehicle speed will be stored in the storage circuit 24. There isn't. Therefore, sudden acceleration and deceleration are prevented,
Driving safety is improved.

As described above, according to the present invention, after the pseudo vehicle speed signal is once stored in the memory by operating the preset switch, the pseudo vehicle speed signal to the memory is cut off. Even if the pseudo vehicle speed signal of the vehicle speed signal generating means changes, the contents stored in the memory do not change, so that the contents of the memory are not changed inadvertently, and safe driving is possible. Furthermore, since the configuration is such that priority is given to the set function, sudden acceleration will not occur even if the preset switch is operated at the same time with the intention of operating the set switch when the preset vehicle speed is higher than the actual vehicle speed. , safety is further improved.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of one embodiment of the present invention, and FIG.
The figure is a waveform diagram for explaining the operation of the embodiment shown in the first figure. 1... Throttle valve, 4... Actuator,
8...Processing device, 10...Vehicle speed detection circuit, 1
2, 23...Switch, 16...Preset vehicle speed setter, 17...Pseudo vehicle speed signal generation circuit, 20...
...Frequency voltage conversion circuit, 24...Memory circuit, 27
...Discrimination circuit, 30...Set switch, 31...
...OR gate, 32...Preset switch, 3
3...NOR gate, 34, 38...AND gate, 35...inverting circuit, 36...monostable circuit, 3
7...Delay circuit.

Claims (1)

[Scope of Claims] 1. Vehicle speed detection means for detecting the actual vehicle speed, a memory for storing the set vehicle speed, a set switch, and a signal representing the actual vehicle speed from the vehicle speed detection means stored in the memory by operation of the set switch. means for deriving a pseudo vehicle speed signal representing the vehicle speed to be preset; a preset switch; means for storing the pseudo vehicle speed signal in the memory by operating the preset switch; and a calculation means for deriving the difference between the two outputs; In the speed traveling device, when the preset switch is operated while the set switch is being operated, a means is provided for prohibiting the preset switch from storing a pseudo vehicle speed signal, and priority is given to storing a signal representing the actual vehicle speed using the set switch. A constant speed traveling device for an automobile, characterized in that: