JPH0543527B2 - - Google Patents

Description

[Detailed Description of the Invention] [Object of the Invention] <Industrial Application Field> The present invention relates to a control circuit for a constant speed traveling device for a vehicle that uses an actuator that is driven by a motor and includes an actuating member that performs a vehicle speed control operation. .

<Prior art> In general, in a constant speed running device for a vehicle, in order to maintain the vehicle speed at a set speed for constant speed running, acceleration/deceleration is performed based on calculations based on the speed difference between the previous and current times in the control cycle, for example. There is something in control. Furthermore, when the vehicle is traveling downhill where running resistance is low, for example, the vehicle speed may continue to increase by accelerating more than the deceleration caused by normal calculation control. Therefore, it is recommended to set an upper limit higher than the set vehicle speed, and when the vehicle speed exceeds the upper limit, fully close the throttle valve and actively use the engine brake to decelerate the vehicle.

By the way, some actuators that perform vehicle speed control operations use a motor as a drive source to improve control accuracy. In this motor-type actuator, a magnetic clutch is interposed between the actuating member connected to the throttle valve and the motor, so that when the vehicle speed exceeds the upper limit as described above, the magnetic clutch is inserted. The clutch can be disengaged, the actuating member can be freed, and the throttle valve can be fully closed.

However, on a long downhill slope, there is a problem in that the magnetic clutch is repeatedly engaged and disconnected near the above-mentioned upper limit, which impairs the durability of the magnetic clutch.

<Problems to be Solved by the Invention> In view of the problems of the prior art, the main object of the present invention is to perform deceleration control to suppress excessive increase in vehicle speed during constant speed driving. It is an object of the present invention to provide a control circuit for a constant speed traveling device for a vehicle that can be smoothly operated.

[Structure of the invention]

<Means for Solving the Problems> According to the present invention, such an object is to calculate the traveling vehicle speed based on a vehicle speed detection signal, and to carry out calculation control to maintain the traveling vehicle speed at a set vehicle speed to perform acceleration and deceleration control. control means for providing a signal;
A vehicle having a motor that rotates in forward and reverse directions based on acceleration and deceleration control signals from the control means, and an actuator that includes a clutch means that selectively connects the vehicle speed control means biased in the deceleration direction to the drive shaft of the motor. In the control circuit of the constant speed traveling device, the control means operates based on a vehicle speed deviation between the traveling vehicle speed and the set vehicle speed until the traveling vehicle speed exceeds a first upper limit value higher than the set vehicle speed. A normal deceleration control signal is supplied to the actuator, and when the traveling vehicle speed exceeds the first upper limit value, the actuator is supplied with a deceleration control signal that becomes an enhanced value than the normal value determined by the calculation. a second vehicle whose traveling vehicle speed is higher than the first upper limit value;
This is achieved by providing a control circuit for a vehicle constant speed running device, which is characterized in that it supplies a clutch disengagement signal to the clutch means when the upper limit of .

<Function> In this way, when the traveling vehicle speed becomes higher than the set vehicle speed, the deceleration control signal is first strengthened compared to the normal deceleration control signal calculated based on the vehicle speed deviation between the traveling vehicle speed and the set vehicle speed. A deceleration control signal is supplied to the actuator, and when the traveling vehicle speed increases, a clutch disengagement signal is supplied to the clutch means, so that when the traveling vehicle speed increases, the clutch is not immediately disengaged at the upper limit value. First, deceleration control is performed at a value that is stronger than normal, and then when the traveling vehicle speed increases, the clutch is disengaged, thereby making it possible to smoothly suppress the excessive increase in the traveling vehicle speed.

<Examples> Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In FIG. 1, a forward/reverse drive circuit for a motor 2 serving as a drive source for an actuator 1 of a vehicle constant-speed traveling system is constructed by a transistor bridge circuit of a known type consisting of four transistors Q1 to Q4. . An operating member 4 is connected to the drive shaft of the motor 2 via a magnetic clutch 3, and a throttle valve 6 is connected to the operating member 4 via a throttle wire 5. These operating member 4, throttle wire 5, and throttle valve 6 constitute vehicle speed control means for controlling vehicle speed. Therefore, when the magnetic clutch 3 is in the connected state, the throttle valve 6 is interlocked with the rotation of the motor 2.

In the bridge circuit described above, the emitters of the transistors Q1 and Q2 are connected to the power supply terminal V, and the emitters of the transistors Q3 and Q4, whose collectors are respectively connected to the collectors of the transistors Q1 and Q2, are Grounded. Furthermore, both terminals of the motor 2 are connected to the connection point between the collectors of the transistors Q1 and Q3 and the connection point between the collectors of the transistors Q2 and Q4 via normally closed limit switches 8 and 9, respectively. Therefore, by supplying an ON signal from the control circuit 7 to the transistors Q1 and Q4, the motor 2 is rotated in a direction that drives the actuating member 4 to the acceleration side, which is the fully open side of the throttle valve 6, or the transistors Q2 and Q4 are turned on. By turning on Q3, the motor 2 is rotated in a direction that drives the actuating member 4 to the deceleration side.

Note that each limit switch 8 and 9 is set. Furthermore, limit switch 8
A diode D1 is connected to the direction in which the deceleration side drive current flows to the motor 2, and a limit switch 9 is connected to
Diodes D2 are connected in parallel with each other in the direction in which the acceleration side drive current flows. By doing so, over-rotation of the motor 2 can be suitably prevented.

The excitation coil 10 of the magnetic clutch 3 described above is driven by a transistor Q5 which is controlled on and off by a control circuit 7. Also,
For example, a pulse signal is inputted to the control circuit 7 from the vehicle speed sensor 11, and the traveling vehicle speed is calculated at every predetermined cycle time.

Next, the operation procedure according to this embodiment will be described below with reference to FIG.

When the constant speed running state is set, the magnetic clutch 3 is in the connected state. Further, the calculation control vehicle speed range 12 in which normal acceleration/deceleration control is performed to maintain the running vehicle speed at the set value for constant speed running has a predetermined width above and below the set value, which may be, for example, 4 to 6 km/h. is set. When the traveling vehicle speed fluctuates within this calculation control vehicle speed range 12, the acceleration is calculated from the deviation of the vehicle speed from the set value and the speed difference between the current vehicle speed and the previous vehicle speed every control cycle (for example, 250 ms). Or calculate deceleration. An ON signal whose time changes depending on the control value calculated using these values is supplied from the control circuit 7 to the transistors Q1 and Q4 or the transistors Q2 and Q3, respectively. In this way, the motor 2 rotates toward acceleration or deceleration to maintain the vehicle speed at the set value.

In the area above the calculation control vehicle speed range 12, as described above, the first upper limit value, which is 4 to 6 km/h higher than the set value, is used as the boundary, and the deceleration control value is lower than the control value of the deceleration in the calculation control vehicle speed range 12. A deceleration control vehicle speed range 13 is set for performing predetermined deceleration control with a large deceleration control value. Furthermore, set a second value that is, for example, 10 km/h higher than the set value.
A clutch disengaged vehicle speed range 14 is established above the second upper limit, in which the control circuit 7 supplies an off signal to the transistor Q5 to disengage the magnetic clutch 3. is set.

In the deceleration control vehicle speed range 13, by continuously supplying the deceleration side drive signal to the motor 2, for example, the value is increased compared to the value obtained using calculation in the calculation control vehicle speed range 12. Deceleration control is performed by value. Note that this deceleration side drive signal may be supplied discontinuously as a pulse having a width larger than the pulse width of the deceleration side drive signal in the calculation control vehicle speed range 12.

When the traveling vehicle speed reaches the clutch disengaged vehicle speed range 14, the operating member 4 becomes free due to the disengaged state of the magnetic clutch 3, so the throttle valve 6 is biased toward the deceleration side by a closing spring (not shown). Therefore, the throttle valve 6 is forced into a fully closed state, and stronger engine braking is obtained, thereby suppressing an excessive increase in vehicle speed. Note that even after the disconnection signal is supplied to the magnetic clutch 3, the deceleration side drive signal continues to be supplied to the motor 2 for a predetermined period of time. Even in this case, the actuating member 4 can be reliably driven to the operating limit on the deceleration side.

In this way, if the vehicle speed continues to increase beyond the calculation control vehicle speed range 12 when driving down a long downhill slope, first, the deceleration is greater than the calculation control range 12 in the deceleration control vehicle speed range 13. It also performs deceleration control. Therefore, since the increase in vehicle speed is further suppressed in the deceleration control vehicle speed range 13, the vehicle speed can be prevented from easily reaching the clutch disengagement speed range 14, and the magnetic clutch 3 can be prevented from repeatedly engaging and disengaging. It can be prevented.

In this embodiment, the second upper limit value is a predetermined value that is 10 km/h higher than the set value, but it may be a function value that changes based on the set value.

〔Effect of the invention〕

According to the present invention, when the traveling vehicle speed becomes relatively higher than the set vehicle speed, first, a deceleration larger than the normal deceleration control signal calculated based on the vehicle speed deviation between the traveling vehicle speed and the set vehicle speed is performed. Since an increase in vehicle speed is suppressed by supplying a control signal to the actuator, it is possible to prevent frequent control to disengage the clutch means due to an excessive increase in vehicle speed. Therefore, the frequency of repeated engagement and disengagement of the clutch means can be suppressed, improving the durability of the clutch means, and smooth deceleration control can be performed since clutch disengagement control is performed after relatively large deceleration control. The effects are extremely large.

[Brief explanation of the drawing]

FIG. 1 is a schematic circuit diagram showing a main part of a control circuit of a constant speed traveling device for a vehicle to which the present invention is applied.
FIG. 2 is a time chart showing the operating procedure of the vehicle constant speed traveling system according to the present invention. 1...actuator, 2...motor, 3...
Magnetic clutch, 4... Operating member, 5... Throttle wire, 6... Throttle valve, 7...
...Control circuit, 8, 9...Limit switch, 10
... Excitation coil, 11 ... Vehicle speed sensor, 12 ...
Arithmetic control vehicle speed range, 13...deceleration control vehicle speed range,
14...Clutch breakage speed range.

Claims (1)

[Scope of Claims] 1. A control means for calculating a traveling vehicle speed based on a vehicle speed detection signal, performing calculation control to maintain the traveling vehicle speed at a set vehicle speed, and supplying acceleration and deceleration control signals; Constant-speed running for a vehicle, comprising: a motor that rotates in forward and reverse directions based on acceleration and deceleration control signals; and an actuator that includes a clutch means that selectively connects a vehicle speed control means biased in the deceleration direction to a drive shaft of the motor. In the control circuit of the device, the control means performs normal deceleration that is calculated based on a vehicle speed deviation between the traveling vehicle speed and the set vehicle speed until the traveling vehicle speed exceeds a first upper limit value higher than the set vehicle speed. supplying a control signal to the actuator, and supplying a deceleration control signal to the actuator that has a value that is enhanced than the normal value determined by the calculation when the traveling vehicle speed exceeds the first upper limit; A control circuit for a constant speed traveling device for a vehicle, characterized in that when the traveling vehicle speed exceeds a second upper limit value higher than the first upper limit value, a clutch disengagement signal is supplied to the clutch means.