JP2543233Y2 - Constant speed traveling device - Google Patents

Description

[Detailed description of the invention]

[0001]

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

[0002]

2. Description of the Related Art Various types of conventional constant-speed traveling devices have been provided.
No. 530 is known.

[0003] This is because a set switch for setting a set speed to set the current vehicle speed to a predetermined speed, a cruise control is started again after releasing the constant speed traveling control (cruise control), or A resume / accelerate switch for increasing a vehicle speed set by a switch, a cancel switch for canceling the cruise control, and a microcomputer for controlling a throttle actuator based on signals from the switches. The set switch and the resume / accelerate switch are connected to a microcomputer via a pair of voltage input ports. On the other hand, the cancel switch is connected to each of the voltage input ports via a shared current limiting resistor and a pair of diodes connected in a forward direction to each other downstream of the current limiting resistor.

When the set switch or the like is turned on, an "H" signal is output to the microcomputer due to the potential difference between the two voltage input ports. When the set switch or the like is turned off, a different potential difference between the voltage input ports is used. An "L" signal is output to the microcomputer to perform cruise control, release of the cruise control, and the like.

[0005]

However, in the above-described conventional constant speed traveling device, the ON / OFF of the set switch and the like is determined by two potentials of "H" and "L" depending on the potential difference of the voltage input port.
Since only one of the two diodes is used for detection, if one of the two diodes is broken open for some reason, the following problem occurs.

That is, for example, when the set switch is turned on, that is, when the cancel switch is turned on to stop the constant speed running during the cruise control at a predetermined set vehicle speed, the voltage input port on the set switch side becomes "L". "
The voltage input port on the resume / accelerate switch side is set to “H”, so that the microcomputer may perform control when the resume / accelerate switch is on.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and comprises a set switch for setting a vehicle speed to a predetermined speed, a change switch for changing the set vehicle speed, and the like. A cancel switch for canceling the constant-speed traveling; and a control unit for controlling a throttle actuator in accordance with output signals input from the switches through a plurality of voltage input ports, wherein the cancel switch and each voltage input port are provided. In a constant-speed traveling device in which a shared current-limiting resistor and a separate diode are connected, a shunt resistor is connected between each diode and each voltage input port. Features.

[0008]

According to the present invention, the on / off signals from the switches to the microcomputer can be detected not only by the "H" and "L" signals but by the potential difference signals of at least three regions. it can. That is, as for the ON / OFF signals of each set switch and change switch, the potential difference at each voltage input port is in a high region and a low region, while the voltage of the cancel switch system has a potential difference by a current limiting resistor and each shunt resistor. It is controlled to be in the middle area. Therefore, for example, if the diode on one side of the cancel switch breaks open,
When the cancel switch is turned on during the cruise control, a potential difference signal between the low range and the middle range is input to each voltage input port. Accordingly, the microcomputer can perform control for canceling the cruise control by determining that the cancel switch is turned off based on such a potential difference.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a general configuration diagram showing one embodiment of a constant speed traveling device according to the present invention, wherein 1 is a battery, 2 is a group of sensors and switches for detecting various information, and 3 is each of the sensors. A control unit 4 that calculates a control value for constant-speed traveling based on information signals from the group and the switch group 2 is a throttle actuator that controls a throttle opening amount based on an output signal from the control unit 3.

The sensor group and the switch group 2 include a vehicle speed sensor 5 for rotating a magnet by, for example, a speedometer cable and outputting a pulse signal proportional to the actual vehicle speed in combination with a reed switch. It is provided with a main switch 7 that is turned on and off and supplies the power supply voltage of the battery 1 to the control unit 3 via an ignition switch 6 by an on operation, and a stop lamp switch 8 that releases the cruise control by a brake operation. Further, 9 is a set, coast switch, 10 is a resume or accelerate switch as a change switch, 11 is a cancel switch, and the set and coast switch 9 sets a set speed to set the current vehicle speed to a predetermined speed. Or lower the set speed. The resume / accelerate switch 10 is for starting the cruise control again after canceling the cruise control or for increasing the speed set by the set / coast switch 9. The cancel switch 11 is for canceling the cruise control halfway.

The control unit 3 includes a power supply circuit 12 for inputting the power of the battery 1, a sensor group 2 and the like.
And an input circuit 13 for inputting an output signal from the CPU, and fetching necessary external data from the input circuit 13 in accordance with a program stored in advance in the ROM, and calculating data while transmitting and receiving data to and from the RAM. And a microcomputer 14 for calculating processing values necessary for cruise control and an output circuit 15 for inputting data processed by the microcomputer 14 and outputting control signals for cruise control and fail-safe to the throttle actuator 4. It has.

The throttle actuator 4 includes a vacuum pump 16 for generating a predetermined negative pressure, an air introduction control valve 17 for introducing air, and a fail-safe control valve 1.
8 and a diaphragm drive section 19 which is operated by the vacuum pump 16 and the control valves 17 and 18 to control the throttle opening amount.

The set, coast switch 9
And resume, the accelerated switch 10 is turned on,
The off-state current signal is input to the microcomputer 14 from the voltage input ports P1 and P2 via the input circuit 13.

The cancel switch 11 is turned on,
A current limiting resistor R1 for sharing a current signal when turned off, a first diode D1 and a second diode D2 respectively connected in the forward direction to respective electric circuits of a set, coast switch 9 and resume, and an accelerated switch 10 respectively. Through each voltage input port P1, P2 to the microcomputer 1
4 is input. Furthermore, between the diodes D1 and D2 of the current circuits of the set and coast switch 9 and the resume and accelerate switch 10, and the input circuit 13,
First and second shunt resistors R2 and R3 are connected in parallel. The first and second shunt resistors R2 and R3 are voltage level detecting resistors, one end of which is grounded.

The signals output from the voltage input ports P1 and P2 are subjected to constant voltage processing. In the figure, reference numeral 20 denotes a horn relay coil, and reference numeral 21 denotes a horn switch.

Therefore, according to this embodiment, when cruise control is performed while the vehicle is running, general operation control, that is, when the set / coast switch 9 is turned on, the information signal from each sensor group 2 is transmitted. This is performed by the microcomputer 14 operating and operating the throttle actuator 4 based on the control signal from the output circuit 15.

Here, a description will be given of the potential difference characteristics at the voltage input ports P1 and P2 due to the ON / OFF operation of the switches 9, 10, and 11.

That is, when only the set / coast switch 9 is turned on, the voltage input port P1 is at the power supply voltage V without passing through a resistor, while the voltage input port P2 is at zero voltage. When only the resume / accelerate switch 10 is turned on, the voltage input port P1 becomes zero voltage and the voltage input port P2 becomes power supply voltage V. Further, when both the switches 9 and 10 are turned on, both the voltage input ports P1 and P2 become the power supply voltage V.

When both switches 9 and 10 are turned off and only cancel switch 11 is turned on, both voltage input ports P1 and P2 have voltages obtained by the following equations, respectively.

[0021]

(Equation 1)

Here, VD is the voltage input port P1, P
2 is the operating voltage. Further, the voltage value of P2 is obtained by the same formula. This is because the power supply current V supplied by the ON operation of the cancel switch 11 is applied to the current limiting resistor R1 and the first shunt resistor R2 or the second shunt resistor R2.
3, the voltage level of the cancel switch 11 system is reduced.

Based on the above expression, each switch 9, 10,
Voltage input port P at the time of ON / OFF operation
Table 1 below summarizes the voltage regions of P1 and P2.

[0024]

[Table 1]

As is clear from this table, when each of the switches 9, 10, 11 is turned off, the voltage input port P
1 and P2 are at the zero voltage level (A region), and when only the cancel switch 11 is turned on, the respective ports P1 and P2 are at the medium voltage level (B region) from the above equation. When each of the switches 9, 10, and 11 is turned on, each of the ports P1 and P2 is at a high voltage level (C region).

Therefore, by using the voltage levels of the three stages A, B and C as regions for controlling the microcomputer 14, the first and second diodes D
Even if 1 and D2 are broken open, the cruise control can be released by turning on the cancel switch 11.

That is, for example, when the first diode D1 is broken open for some reason and only the cancel switch 11 is turned on to cancel the cruise control during the cruise control, the voltage input port P1 Side becomes zero voltage, and one voltage input port P2 side becomes

[0028]

(Equation 2)

## EQU1 ##

On the other hand, when the second diode D2 is openly broken, the voltage on the port P2 side becomes zero, and the voltage on the port P1 side becomes zero.

[0031]

(Equation 3)

## EQU1 ## Therefore, from the above equations, the following potential difference relationship is obtained.

[0033]

(Equation 4)

Accordingly, the microcomputer 14 using the potential difference signals of the voltage input ports P1 and P2 shown in Table 1 as control elements performs control according to Table 2 below.

[0035]

[Table 2]

As is clear from this table, A,
Normal operation is determined based on the relative voltage values in the B and C areas, and the voltage values of the voltage input ports P1 and P2 are A and P, respectively.
In the case of the area A, the area A, the area C, the area B, the area B, the area C, the area A is determined to be normal, and the cruise control and the resume control corresponding thereto are performed.
If it is the area, the area B, the area C, the area C, the area B, the area C, C, it is determined that there is an abnormality, and a signal for canceling the cruise control is output to the throttle actuator 4.

In particular, when the cancel switch 11 is turned on in a state where one of the first and second diodes D1 and D2 is openly broken, each port P1
It is determined that the voltage value of P2 is abnormal in the areas A and B and areas B and A, and the cruise control is reliably released.
For this reason, the possibility of erroneous control such as cruise control or resume control is eliminated.

The present invention is not limited to the above-described embodiment. For example, a plurality of stop lamp switches 8 for releasing cruise control may be provided, and the voltage input ports P1 and P2 are provided inside the control unit 3. Instead, it may be arranged outside. .

[0039]

As is apparent from the above description, according to the constant-speed traveling device of the present invention, a common current-limiting resistor and an individual diode are connected between the cancel switch and each voltage input port. In addition, since a shunt resistor is connected between each diode and each voltage input port, at least three voltage value regions can be set for each voltage input port. Therefore, by using the plurality of voltage value areas as an on / off determining element of each switch by the control unit,
Even if each diode is broken open, cruise control and the like can be reliably released by turning on the cancel switch.

[Brief description of the drawings]

FIG. 1 is a schematic view showing an embodiment of a constant speed traveling device according to the present invention.

[Description of Signs] 2 ... Sensors and Switches 3 ... Control Unit 4 ... Throttle Actuator 9 ... Set, Coast Switch 10 ... Resume, Accelerate Switch, 11 ... Cancel Switch, P1, P2 ... Voltage Input Port , R1 ... current limiting resistors, R2, R3 ... shunt resistors, D1, D2 ... diodes.

Claims (1)

(57) [Scope of request for utility model registration] 1. A set switch for setting a vehicle speed to a predetermined speed, a change switch for changing the set vehicle speed and the like, a cancel switch for canceling the constant speed traveling, and a plurality of voltage input ports from the switches. And a control unit for controlling the throttle actuator in accordance with the output signal inputted thereto. A constant current limiting resistor and a separate diode are respectively connected between the cancel switch and each voltage input port. In the high-speed traveling device, a shunt resistor is connected between each of the diodes and each of the voltage input ports.