JPS61139523A - Constant speed running device - Google Patents

Abstract

PURPOSE:To shorten the braking time of a d.c. motor, by a method wherein the counter electromotive force of a d.c. motor, generated during operation of a limit switch on the accelertion side or on the deceleration side detecting opening at a given opening or more or less of a throttle valve, is short-circuited or consumed by means of a-3-terminal switch and a diode. CONSTITUTION:When, for example, an acceleration signal 1a is provided from a control circuit 1, the signal is returned to the control circuit 1 through a limit switch 102 on the deceleration side, a d.c. motor 2, and a limit switch 101 on the acceleration side. This causes rottion of the d.c. motor 2, and causes a throttle valve 9 to be rotated in an acceleration direction through the medium of a deceleration mechanism 3 and a cable 6. When, during said operation, the limit switch 101 on the acceleration side is opened, an acceleration signal 1a is shut off by a diode 103 with polarity reverse to that of the signal 1a. The d. c. motor 2 is driven by inertia to generate an electromotive force, but the electromotive force flows in a direction reverse to that of the acceleration signal 1a and is returned to the d.c. motor 2. Thereby, the electromotive force is consumed and the d.c. motor 2 is rapidly braked.

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention detects the actual vehicle speed, compares the actual vehicle speed with a set vehicle speed, and automatically controls the throttle to set the vehicle speed based on the comparison result. This invention relates to a constant speed traveling device that maintains vehicle speed.

[Conventional technology]

A conventional device of this type is shown in FIG.

In the figure, 1 is a control circuit that compares a preset vehicle speed with the actual vehicle speed and outputs a speed increase signal 1a or a deceleration signal 16 of opposite polarity, and 2 is a control circuit that outputs a speed increase signal 1a or a deceleration signal 16 of opposite polarity. Upon receiving the deceleration signal 1b, the throttle valve 9
3 is a worm wheel 3 that meshes with a worm 3a connected to the DC motor 2;
b, a reduction mechanism 4 is connected to the worm wheel 3b, and a cable 6 connected to the throttle link 5;
The throttle valve 9 installed in the intake manifold 8 is interlocked with the accelerator pedal. 10 is a transmission connected to an engine (not shown); 11 is this transmission 10;
12 is a speed sensor driven by the speedometer flexible shaft 11 (magnet) 12a and a reed switch 12b.
It consists of 13 is throttle pal 7” 9 (D
This is a normally closed speed increase side limit switch that turns OFF when the opening exceeds a predetermined opening, and a diode 14 of opposite polarity to the speed increase signal 1a is connected in parallel.

Reference numeral 15 denotes a normally closed deceleration side limit switch which is turned off when the adjustment of the throttle valve 9 becomes less than a predetermined opening degree, and a diode 16 having a polarity opposite to the deceleration signal 1b is connected in parallel. In addition, these speed increasing side limit switches 1
3 and deceleration side limit switch 15 are control circuit 1, respectively.
and the DC motor 2 in series. 17 is a speed increase side stopper that mechanically protects the speed increase side limit switch 13 by restricting the rotation of sector 4 after the speed increase side limit switch 13 is turned OFF, and 18 is a speed increase side stopper which similarly protects the speed increase side limit switch 15 when the speed increase side limit switch 15 is turned OFF. The rear stopper is a deceleration side stopper that limits and protects the rotation of the sector 4.

In the constant speed traveling device configured in this way, when traveling at a constant speed, the amount of air-fuel mixture to be supplied into the cylinder of the engine is adjusted by the opening degree of the throttle valve 9, and the vehicle is driven at a desired constant speed. The opening degree of this throttle pulse 7''9 is controlled by the rotational operation of the DC motor 2 in the actuator via the throttle link 5 and cable 6. Also, during normal driving other than constant speed driving, the opening degree of the throttle pulse 7''9 is controlled by the rotation of the DC motor 2 in the actuator. 7 is transmitted to the throttle valve 9 via the throttle link 5.

The DC motor 2 in the actuator rotates in response to the speed increase signal 1a or deceleration signal 1b output from the control circuit 1, and the control of the DC motor 2 is performed in the following process. First, vehicle speed is detected using a speedometer flexible shaft 11 that rotates at a constant ratio with respect to a wheel drive shaft in a transmission 10 installed in the vehicle. Rotate the magnet 12a. The rotational speed of this magnet 12a corresponds to the actual vehicle speed, and the rotational speed is extracted as a pulse using a reed switch 12b. These pulses are counted at fixed time intervals by the control circuit 1 and become the number of pulses corresponding to the actual vehicle speed.

- The number of pulses corresponding to the force setting vehicle speed (target vehicle speed) is counted at regular intervals when setting the vehicle speed, and is set in a vehicle speed setting circuit (not shown) of the control circuit 1. Then, the control circuit 1 compares the number of pulses corresponding to the actual vehicle speed and the number of pulses corresponding to the target vehicle speed, and rotates the DC motor 2 in forward or reverse rotation for a fixed ratio of the difference in the number of pulses in each vehicle speed control cycle. signal to
That is, the speed increase signal 1a or the deceleration signal 1b is output.

In this case, if the actual vehicle speed and target vehicle speed match,
The control circuit 1 does not energize the DC motor 2. Therefore, the opening degree of the sector 4 and the opening degree of the throttle valve 8 are held constant and the vehicle speed does not change. Next, when the actual vehicle speed of the vehicle falls below the target vehicle speed, the control circuit 1 compares the number of pulses corresponding to the actual vehicle speed and the number of pulses corresponding to the target vehicle speed as described above, and calculates the difference in the number of pulses at each control cycle. On the other hand, a speed increase signal 1a is outputted to rotate the DC motor 2 toward the speed increase side for a fixed ratio of time.

When the speed increase signal 1a is given from the control circuit 1, this signal is sent to the deceleration side limit switch 15. DC motor 2. Flows into the control circuit 1 via the speed increase side limiter) 2 switch 13, and as the DC motor 2 rotates, the
Add. Therefore, the opening degree of the throttle valve 9 is also increased to increase the speed of the vehicle and bring it closer to the target vehicle speed. On the other hand, when the actual vehicle speed exceeds the target vehicle speed, the control circuit 1 compares the number of pulses as described above, and shifts the DC motor 2 to the deceleration side for a fixed ratio of the difference in the number of pulses in each control cycle. A deceleration signal 1b for rotation is output. When a deceleration signal 1b is given from the control circuit 1, this signal is sent to the speed increasing limit switch 13,
The current flows to the control circuit 1 via the DC motor 2 and the deceleration side limit switch 15, and as the DC motor 2 rotates, the sector 4
The degree of opening is decreased. Therefore, the opening degree of the throttle valve 9 decreases, and the vehicle decelerates and approaches the target vehicle speed.

By the way, when the DC motor 2 rotates in the speed increasing direction in response to the speed increase signal 1a from the control circuit 1 and the opening degree of the throttle valve 9 is increased, if the opening degree of the throttle valve 9 exceeds a predetermined degree. Speed increase side limit switch 13 is FF
Since the diode 14 has a polarity opposite to the speed increasing signal 1a, the speed increasing signal 1a is cut off and the speed increasing operation is stopped.

At this time, when the deceleration signal 1b is applied, the deceleration signal 1b flows to the control circuit 1 via the diode 14, the DC motor 2, and the deceleration side limit switch 15 even if the speed increase side limit switch is FF, and the DC motor 2 It can rotate in the direction of deceleration. On the other hand, when the DC motor 2 rotates in the deceleration direction in response to the deceleration signal 1b from the control circuit 1 and reduces the opening degree of the throttle valve 9, if the opening degree of the throttle valve 9 becomes less than the predetermined opening degree. Since the deceleration side limit switch 15 is FF L and the diode 16 has the opposite polarity to the deceleration signal 1b, the deceleration signal 1b is cut off and the deceleration operation is stopped. At this time, if the speed increase signal 1a is given, even if the deceleration side limit switch 15 is FF, the speed increase signal 1a will be applied to the diode 16 and the DC motor 2.
, flows to the control circuit 1 via the speed-increasing limit switch 13, and the DC motor 2 can rotate in the speed-increasing direction.

[Problem that the invention seeks to solve]

In such a conventional constant speed traveling device, if the limit switch 13.15 is turned OFF while the DC motor 2 is rotating in response to a control signal from the control path 1, the polarity is reversed to the control signal. Although the control signal is cut off by the included diodes 14 and 16, the DC motor 2 does not stop instantaneously due to inertial force.

During this time, the DC motor 2 generates an electromotive force as a generator, but since this electromotive force is not consumed rapidly, it takes time for the DC motor 2 to stop. Therefore, sector 4 is stopper 17,
Since the DC motor 2 continues to rotate even though the number of rotations is limited by 18, there is a problem in that excessive force is applied to the speed reduction mechanism 3, and in severe cases, the speed reduction mechanism 3 may be damaged. .

The present invention has been made to solve the above problems, and an object of the present invention is to provide a constant speed traveling device in which the braking time of the DC motor when the limit switch is activated is significantly shortened, and the reliability is improved.

[Means for solving problems]

The constant speed traveling device according to the present invention has a common terminal connected to a DC motor, a normally closed terminal connected to a control circuit, and a spout.
A limit switch on the acceleration side and a limit switch on the deceleration side are provided, each consisting of a common terminal and a normally open terminal that are connected when the throttle pulp opening is above or below a predetermined level, and these normally open terminals are connected to each other. First and second diodes having positive polarity in this direction are connected between the normally closed terminal and the normally open terminal.

[Effect]

In the constant-speed traveling device of the present invention, when the speed-increasing limit switch is activated, the speed-increasing signal is cut off by the first diode, and the back electromotive force of the DC motor is transferred to the normally closed terminal of the decelerating-side limit switch, and the second diode, shorted through the normally open terminal of the limit switch on the speed increasing side, and consumed. Furthermore, when the deceleration side limit switch is activated, the deceleration signal is cut off by the second diode, and the back electromotive force of the DC motor is transferred to the normally closed terminal of the speed increase side limit switch, the first diode, and the normally open terminal of the deceleration side limit switch. Short circuited through the terminal, consumed.

〔Example〕

FIG. 1 shows the overall configuration of a constant speed traveling device according to an embodiment of the present invention, and FIGS. 2 to 4 are circuit diagrams illustrating the operation of the main parts thereof. In these figures, 101 indicates a common terminal 101a, a normally closed terminal 101b, and a normally open terminal 10.
1c, the common terminal 101a is connected to one terminal of the DC motor 2, and the normally closed terminal 101b is connected to the output part (not shown) of the deceleration signal 1b of the control circuit 1. has been done. 102 is a common terminal 102a
, a deceleration side limit switch composed of a normally closed terminal 102b and a normally open terminal 102c, the common terminal 102a is connected to the other terminal of the DC motor 2, and the normally closed terminal 102b is connected to the output part of the speed increase signal 1a of the control circuit 1 ( (not shown). Reference numeral 103 denotes a first diode that becomes positive and opposite polarity with respect to the deceleration signal 1b from the control circuit 1 when the common terminal 101a of the speed increasing limit switch 101 is connected to the normally open terminal 101c; 104 represents the decelerating limit switch 102; When the common terminal 102a is connected to the normally open terminal 102cK, the second
diode. In addition, the speed increase side limit switch 1
01 normally open terminal 101c and deceleration side limit switch 10
The two normally open terminals 102c are connected to each other. In the normal state, this constant speed traveling device has a speed increase side limit switch 101 and a speed reduction side limit switch 102.
N1, that is, common terminals 101a and 102a are connected to normally closed terminals 101b and 102b. Since the other configurations are the same as those of the conventional device shown in FIG. 5, corresponding parts are given the same reference numerals and explanation thereof will be omitted.

Next, the operation of the constant speed traveling device having the above configuration will be explained. Here, the control circuit 1 outputs a speed increase signal 1a and a deceleration signal 1b by the same operation as in the conventional device. First, as shown in FIG.
When the speed increase signal 1a is given from the deceleration side limit switch 102, this signal is sent to the normally closed terminal 102b of the deceleration side limit switch 102, the common terminal j02a, and the DC motor 2. Speed increase side limit switch 10
The DC motor 2 is returned to the control circuit 1 via the common terminal 101a and the normally closed terminal 101b, thereby causing the DC motor 2 to rotate and increase its speed. Furthermore, when the control circuit 1 gives the deceleration signal 1b, this signal is sent to the speed increasing limit switch 10.
1 normally closed terminal 101b, common terminal 101a, DC motor 2. Common terminal 102 of deceleration side limit switch 102
a, it is returned to the control circuit 1 via the normally closed terminal 102b, and the DC motor 2 is reversely rotated to perform deceleration.

Next, as shown in FIG. 3, upon receiving the speed increase signal 1a from the control circuit 1, the DC motor 2 rotates and performs a speed increase operation.

If the speed increase side limit switch 101 is activated during the operation, the common terminal 1 of the speed increase side limit switch 101
01a is the normally open terminal 101 separated from the normally closed terminal 101b.
Connect to c. At this time, the speed-increasing signal 1a is cut off because the first diode 103 has the opposite polarity to the speed-increasing signal 1a. The DC motor 2 continues to rotate due to inertia force and generates an electromotive force as a generator, but this electromotive force flows in the opposite direction to the speed increase signal 1a, and the common terminal 102a of the deceleration side limit switch 102 is normally Closed terminal 102b
s second diode 104. Speed increase side limit switch 1
The normally open terminal 101cp of 01 is returned to the DC motor 2 through the common terminal 101a, the electromotive force is short-circuited and consumed, and the DC motor 2 is rapidly braked. Further, when the deceleration signal 1b is applied from the control circuit 1 while the speed increasing limit switch 101 is activated, the deceleration signal 1b is transmitted to the first diode 1o3. Normally open terminal 101c of speed increasing limit switch 101, common terminal 101a, DC motor 2. Common terminal 102a of deceleration side limit switch 102, returns to control circuit 1 via normally closed terminal 102b), DC motor 2
can rotate in the direction of deceleration. If a micro switch or the like is used as the speed increase side limit switch 101, the speed increase side limit switch 10 will change as the DC motor 2 rotates.
The connection of the common terminal 101a of No. 1 is instantly switched from the normally open terminal 101c to the normally closed terminal 101bK, allowing normal speed-up and deceleration operations.

Contrary to the case where the speed increase side limit switch 101 is activated, when the deceleration side limit switch 102 is activated while the DC motor 2 is decelerating in response to the deceleration signal 1b from the control circuit 1, the fourth limit switch 102 is activated. As shown in the figure, the connection of the common terminal 102a of the deceleration side limit switch 102 is switched from the normally closed terminal 102b to the normally open terminal 102c.
Since the second diode 104 has the opposite polarity to the deceleration signal 1b, the deceleration signal 1b is cut off. The DC motor 2 continues to rotate (due to inertial force) and acts as a generator, generating an electromotive force in the opposite direction to the deceleration signal 1b.

This electromotive force is applied to the common terminal 101a of the speed increasing limit switch 101, the normally closed terminal 101b, and the first diode 1.
03. Normally open terminal 102 of deceleration side limit switch 102
c, return to the DC motor 2 via the common terminal 102a,
The electromotive force is short-circuited and consumed, and the DC motor 2 is rapidly braked and stopped. When the speed increase signal 1a is given from the control circuit 1 in a state where the above-mentioned deceleration side limit switch 102 is activated, the speed increase signal 1a is passed through the second diode 104. A normally open terminal 102c and a common terminal 102a of the deceleration side limit switch 102.

DC motor 2. It is returned to the control circuit 1 via the common terminal 101a and the normally closed terminal 101b of the speed increasing side limit switch 101, and the DC motor 2 can rotate in the speed increasing direction. If a micro switch is used for the deceleration side limit switch 102 like the speed increase side limit switch 101 described above, the common terminal 102a of the deceleration side limit switch 102 becomes the normally open terminal 10 as the DC motor 2 rotates in the speed increasing direction.
The connection is instantly switched from 2C to the normally closed terminal 102b, allowing normal speed-up and deceleration operations.

〔Effect of the invention〕

As described above, according to the constant speed traveling device of the present invention, the back electromotive force of the DC motor generated when the limit switch is activated is short-circuited and consumed using a three-terminal switch and a diode. Braking time is significantly shortened, there is no risk of damage to the speed reduction mechanism, and reliability is improved.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the configuration of a constant speed traveling device according to an embodiment of the present invention, FIGS. 2 to 4 are circuit diagrams for explaining the operation of the main parts of the constant speed traveling device, and FIG. The figure is a diagram showing the configuration of a conventional constant speed traveling device. DESCRIPTION OF SYMBOLS 1... Control circuit, 1a... Speed increase signal, 1b... Deceleration signal, 2... DC motor, 9... Throttle valve, 12... Speed detector, 101... Speed increase Side limit switch, 102... Deceleration side limit switch, 1
01a. 102a - common terminal, 101b, 102b -...
Normally closed terminal, 101c, 102e... Normally open terminal, 1
03...First diode, 104... Second diode. Note that the same reference numerals in the figures indicate the same or corresponding parts.

Claims (1)

[Claims] A control circuit that detects the vehicle speed and compares it with a preset vehicle speed, and outputs an accelerating signal or a decelerating signal with the opposite polarity to the accelerating signal based on the comparison result.The accelerating signal and decelerating signal are used to control the throttle valve a DC motor that opens and closes the throttle valve and maintains the vehicle speed at a set vehicle speed by the opening degree of the throttle valve; a common terminal connected to one terminal of the DC motor; The speed increasing side consists of a normally closed terminal that is separated from the common terminal when the valve opening exceeds a predetermined opening, and a normally open terminal that is connected to the common terminal when the throttle valve opening exceeds a predetermined opening. A limit switch, connected to a common terminal connected to the other terminal of the DC motor and the speed increase signal output side of the control circuit, and separated from the common terminal when the throttle valve opening becomes less than a predetermined opening. A deceleration side limit switch comprising a normally closed terminal and a normally open terminal connected to the normally open terminal of the speed increase side limit switch and connected to the common terminal when the throttle valve opening falls below a predetermined opening. , a first diode connected between the normally closed terminal and the normally open terminal of the speed increase side limit switch so as to have a positive polarity with respect to the deceleration signal, the normally closed terminal and the normally open terminal of the speed increase side limit switch. A constant speed traveling device, comprising: a second diode connected between and having a positive polarity with respect to a speed increasing signal.