JPH0546082Y2 - - Google Patents

Description

[Detailed explanation of the invention] Industrial application field This invention detects the magnetic field generated in the guiding wire,
The present invention relates to a guide device for a guided vehicle that performs automatic travel control based on this detection output.

Conventional technology A magnetic field is generated by passing an alternating current through a guide wire laid on a running road surface such as a floor, this magnetic field is detected by a detection coil, and steering wheels are steered along the guide wire according to the detection output. Transport vehicles that run unmanned are known (for example, disclosed in Japanese Patent Publication No. 53-26753 and Japanese Utility Model Application Publication No. 125932-1983).

Problems to be Solved by the Invention In this type of guiding device for a guided vehicle, a detection coil for detecting a magnetic field is installed as follows. For example, in the conveyance vehicle disclosed in Japanese Patent Publication No. 53-26753, as shown in FIG. , and are arranged symmetrically with respect to the front wheels 4, so that the detection coils 3a, 3b are steered together with the front wheels 4 when the steering is operated. Also, in 1977-
In the conveyance vehicle disclosed in Publication No. 125932, as shown in FIG. 9, a triangular frame-shaped arm 12 is attached to the front of the vehicle body 11 and extends forward in a horizontal direction in conjunction with steering operation. A pair of detection coils 13a and 13b are arranged on both sides of the tip of the arm 12.

However, for example, in the case of a forklift with rear wheel steering, the steering mechanism does not have a triangular frame-shaped arm or a steering shaft for steering like a three-wheeled automatic guided vehicle. It has not been possible to configure the detection coil to follow the steered steering wheel by using the frame or the steering shaft.

By the way, the output voltage detected by the detection coil changes depending on the distance between the detection coil and the guide wire, and the closer the two are, the higher the output voltage becomes. Voltage fluctuations are large (high sensitivity to deviations), and output voltage fluctuations are small depending on distance changes when both are separated.

Due to these characteristics of the detection coil, when traveling along the straight part of the guide line, that is, when the running wheels are not being steered, the sensitivity to deviations is low to avoid unnecessary movement (meandering), and when traveling along the curved part of the guide line. When traveling along the road, that is, when steering the steering wheels, it is desirable to be highly sensitive to deviations to avoid derailment.

However, in the conventional guided vehicle guidance device described above, the distance between the pair of detection coils 3a, 3b and the detection coils 13a, 13b is fixed, and even when the guided vehicle travels on a straight section, it also travels on a curved section. Even when doing so, the distance between the guide wire and the detection coil is always constant. As a result, the sensitivity to deviations is the same for straight sections and curved sections, so if you improve the sensitivity to deviations so that you can drive optimally on curved sections, you will be able to greatly steer the traveling wheels even in response to small deviations. This means that the train will have to make corrections in its direction of travel, leading to meandering in the straight section and possibly derailment. Therefore, when attempting to run smoothly not only on straight sections but also on curved sections, it is not possible to increase the traveling speed on the straight sections, which poses a problem in terms of conveyance efficiency.

Therefore, the present applicant has developed and applied for a guided vehicle guidance device in which the detection coil is movable so as to increase the sensitivity to deviations in curved portions (Utility Application No. 122273/1983). No. 63-31406,
Jitsuhei No. 5-7609)).

As shown in FIG.
Two links 23a and 23b are provided which swing while maintaining a mutually parallel state by steering the steering wheel 2, and a pair of detection coils 24a and 24b are attached to these two links 23a and 23b. When the transport vehicle 21 approaches a curved portion, the distance between the detection coils 24a, 24b and the guide wire G changes, so the steering wheels 22 are adjusted to correct this.
is steered and starts traveling along the guide line G. At this time, the pair of links 23a and 23b rotate in conjunction with the steering wheel 22 while maintaining a parallel state in the same direction, and each detection coil 24a and 24b approaches the guide line G, respectively. As a result, the sensitivity to deviations caused by the detection coils 24a and 24b is increased in the curved portion, and the train is allowed to travel through the curved portion without derailing.

However, in this guided vehicle guidance device, the pair of detection coils 24a, 24
Although the distance between B and guide line G approaches, the amount of approach is small, and the sensitivity to deviations in curved sections is still insufficient, so it is not always possible to run at a sufficiently high speed in curved sections. Ta.

This idea was created in view of the above problems.
It is an object of the present invention to provide a guiding device for a conveyance vehicle that can guide a guided vehicle so that it can travel at high speed not only on straight sections but also on curved sections.

Means for Solving the Problems As a means for solving the above problems, the guided vehicle guiding device of this invention detects the magnetic field generated in the guiding wire with a pair of detection coils located on both sides of the guiding wire. The actuator is actuated in accordance with the detection output of the detection coil, and the actuator steers and drives the steering wheel via a steering link mechanism having a tie rod and a knuckle arm, thereby guiding the vehicle to travel along the guide line. The guiding device for a transport vehicle is characterized in that the pair of detection coils are supported by a tie rod or a knuckle arm so as to follow the movement of steered steering wheels.

Effect With the above configuration, when the conveyance vehicle approaches a curved portion, the distance between the pair of detection coils and the guide wire changes, so the steering wheels are steered to correct this. . When the steering wheels are steered, a pair of detection coils supported by tie rods or knuckle arms of the steering link mechanism follow the steering wheels and move in the direction of the guide line to prevent derailment. Furthermore, since the pair of detection coils that follow the steered steering wheels are arranged at the lowest part of the vehicle body, they can move or turn without interfering with the vehicle body, and they can Since there is no magnetic material in
Accurately detect the magnetic field generated by the guide wire to accurately guide the running direction. Furthermore, the detection coils move or turn to follow the steered steering wheels, and each detection coil approaches the guide line direction, so the sensitivity of each detection coil to deviations becomes high. The train can run smoothly at high speed along the guide line without derailing at curved sections.

Embodiments Hereinafter, embodiments of this invention will be described based on the drawings.

Figures 1 to 5 show a first embodiment in which this invention is applied to a guidance system for an unmanned forklift. front wheel 3
A fork 33 is provided in front of the forks 2 and 32 so as to be movable up and down and tiltable. Further, rear wheels 34, 34, which are steering wheels, are provided at the rear of the vehicle body 31, and a counterweight 35 is provided behind the rear wheels 34, 34. A driver's seat 31a and a steering wheel 31b are provided for use when traveling.

Further, the rear wheels 34, 34, which are steering wheels,
Knuckle shafts 3 are installed at the left and right ends of the over beam 36 and under beam 37, which are arranged in two stages, upper and lower.
8 and 39 so as to be steerable via knuckle arms 40 and 41 which are swingably provided.

On the other hand, the steering link mechanism S that steers the rear wheels 34, 34 includes a bell crank 42 and a bell crank 4.
The power steering cylinder 43 rotates the bell crank 42, and the knuckle arm 4 rotates the bell crank 42.
0 and 41, and tie rods 44 and 45 for transmitting power to the terminals 0 and 41. The bell crank 42 is disposed in a space between the over beam 36 and the under beam 37, and is supported so as to be horizontally rotatable about a rotation shaft 42a provided on the center line of the vehicle body. The tip of the rod 43a of the power steering cylinder 43 is connected to the force point of the bell crank 42, and the two tie rods 44, 45 are connected to the two force points of the bell crank 42.
One tie rod 4 is attached to the top side of the bell crank 42.
One end of the tie rod 4 is rotatably connected to the lower surface side of the other tie rod 45, and the rod ends of the other tie rods 44 and 45 are rotatably connected to the ends of the knuckle arms 40 and 41, respectively. connected.

Detection coils 46 and 47 are connected to the tie rods 44 and 45 at their proximal ends.
Stay 48 connected near each rod end of 5,
It is attached via 49. Both stays 4
8 and 49 are members 48a and 49a whose upper ends are connected to tie rods and extend vertically downward; members 48b and 49b which extend from the lower ends of these members 48a and 49a toward the rear of the vehicle body; and members 48b and 49b extending from the rear ends of these members 48b and 49b. Members 48c and 49 extending in the direction of the vehicle center line
The detection coils 46 and 47 are attached to the tip sides of the members 48c and 49c extending in the direction of the center line of the vehicle body, and are disposed below the under beam 37 at the lowest part of the vehicle body. When the rear wheels 34, 34 are running straight,
Both detection coils 4 are installed at the same distance from the vehicle center line and at the same height from the road surface.
6 and 47 are arranged close to the running road surface on which the guide wire G is laid, and both detection coils 46 and 47
The magnetic body is arranged so that no part of the vehicle body is interposed between the vehicle body and the running road surface to reduce the influence of external disturbances, and both detection coils 46 and 47 detect the over beam 36 and the under beam during steering. 37, bell crank 42, counterweight 35, and connection portion 35a of the counterweight 35 to the vehicle body side
It is arranged so that it does not interfere with other equipment.

Next, the operation of the first embodiment configured as described above will be explained.

When the forklift 30 loads cargo onto a fork 33 and transports it, the forklift 30 moves backwards with its rear wheels 34 in the forward direction of movement, and uses a pair of magnetic fields generated by a guide wire G laid on the road surface. The vehicle is detected by the detection coils 46 and 47, and is steered so that the detection outputs detected by both the detection coils 46 and 47 are equal, and the vehicle travels unmanned along the guide line G while automatically correcting the direction of travel.

When the forklift 30 is guided by the guide line G and travels along a straight line, the two detectors attached to the stays 48 and 49 whose proximal ends are supported near the respective rod ends of the tie rods 44 and 45 of the steering linkage S are used. The coils 46 and 47 are arranged at appropriate distances from the guide wire G, so that the sensitivity to deviations does not become too high, and the meandering that occurs when the sensitivity to deviations is too high and even the slightest deviation is detected. (See Figure 2).

When the forklift 30 reaches, for example, a right curve, both the detection coils 46,
47, the right curve of the guide line G is detected, and the power steering cylinder 43 is actuated by an amount corresponding to the curvature of the guide line G, and the bell crank 42 of the steering link mechanism S is moved by a predetermined amount. Drive only rotationally. When the bell crank 42 rotates,
Tie rods 44, 45 have one end connected to the bell crank 42, and a knuckle arm 4 to which the rod ends of each tie rod 44, 45 are connected.
Both the left and right rear wheels 34, 34 are steered by a predetermined angle via the wheels 0, 41.

Both the left and right rear wheels 34, 34 are steered, and the forklift 30 travels along the guide line G of the curved portion. At this time, as both rear wheels 34, 34 are steered to a predetermined steering angle, both tie rods 4
4 and 45 respectively move in the bending direction of the guide wire G at the curved portion, the positions of the detection coils 46 and 47 supported by both tie rods 44 and 45 via stays 48 and 49 are also in the same direction. and is placed in a close position above the guide line G (see Figure 3).

Therefore, when the forklift 30 travels around a curved portion, the rear wheels 34, 3, which are traveling wheels,
4 is steered, both detection coils 46,
Since the positions of the detection coils 47 move in the direction closer to the guide wire G, the sensitivity of the detection coils 46 and 47 to deviations is increased, and as a result, deviations in curved portions can be corrected accurately in a short time. This improves driving performance such as high speed and minimum turning radius during unmanned driving around curves.

6 and 7 show a second embodiment of this invention, in which the detection coil, which was supported by the tie rod via the stay in the first embodiment, is replaced by the same steering wheel. It is supported by the knuckle arm of the link mechanism, and the same components as in the first embodiment are designated by the same reference numerals.
A detailed explanation thereof will be omitted.

The forklift 50 has rear wheels 34, 34, which are steering wheels, at the rear of a vehicle body 31, and an overbeam 3.
The rear wheels 34 and 34 are provided at both ends of the under beam 37 and supported by knuckle shafts 38 and 39, respectively, so that the rear wheels 34 and 34 can be steered.
The vehicle is steered by driving a steering link mechanism S disposed in a space between the counterweight 35 and the counterweight 35 by a power steering cylinder 43.

The steering link mechanism S includes a bell crank 42 that is horizontally rotatably disposed around a rotation shaft 42a provided on the center line of the vehicle body, and two points of action formed on the bell crank 42. Two tie rods 4 with one end of each rotatably connected to the
4, 45, and a knuckle arm 4 which rotatably connects each rod end side of both tie rods 44, 45.
0,41, and the bell crank 42
By rotating the rear wheels 34, 34 with the power steering cylinder 43, the rear wheels 34, 34 to which the respective knuckle arms 40, 41 are connected are steered.

Detection coils 56 and 57 of the guidance device that causes the forklift 50 to run unmanned by detecting the magnetic field generated by the guidance wire G are attached to the ends of the knuckle arms 40 and 41 of the steering linkage S. They are attached via stays 58 and 59, respectively, and are disposed below the under beam 37 at the lowest part of the vehicle body, and are at the same distance from the center of the vehicle body and at the same distance from the road surface when the rear wheels 34 and 34 are traveling straight. It is installed at a height.
Therefore, both detection coils 56 and 57 are connected to the guide wire G.
As you approach the driving road surface where
By arranging the vehicle body, which is a magnetic material, between the two detection coils 56, 57 and the road surface, the influence of external disturbances can be reduced, and both the detection coils 56, 57 during steering can be 57 is over beam 36, under beam 37, bell crank 4
2. It is arranged so as not to interfere with the counterweight 35 and the connecting portion 35a of the counterweight 35 to the vehicle body side.

The forklift 50 configured in this way is
When the fork 33 is loaded with cargo and transported, the fork 33 travels backwards with the rear wheels 34, 34 forward in the traveling direction, and a pair of detection coils 56, 57 detect the magnetic field generated by the guide wire G laid on the traveling road surface. The vehicle is steered so that the detection outputs detected by both detection coils 56 and 57 are equal, and the vehicle travels unmanned along the guide line G while automatically correcting the direction of travel.

And this unmanned forklift 50
When, for example, a right curve is reached, the right curve is detected from the difference between the detection outputs of the two detection coils 56 and 57, and the bell crank 42 is moved by the power steering cylinder 43 by an amount corresponding to the curvature of the guide line G.
is rotationally driven, and tie rods 44, 45, one end of which is connected to the bell crank 42, steer the left and right rear wheels 34, 34 by a predetermined angle via knuckle arms 40, 41, so that the forklift 50 moves around the curved section. The vehicle travels along the guide line G. At this time,
When both the rear wheels 34, 34 are steered to a predetermined steering angle, the knuckle arms 40,
41 rotates, each knuckle arm 4
Detection coils 56 and 57 provided at 0 and 41 via stays 58 and 59 are the rear wheels 3 to be steered.
4 and 34, it rotates in the steering direction and moves to a close position above the guide line G (see FIG. 7).

Therefore, when the forklift 50 travels on a curved portion, the rear wheels 34, 3, which are the traveling wheels,
4 is steered, both detection coils 56,
57 move in the direction approaching the guide line G, the sensitivity to the deviation of the detection output becomes high, and as a result, the correction of the deviation in the curve part is performed accurately in a short time. Driving performance such as high speed performance and minimum turning radius will be improved during unmanned operation.

In both of the above embodiments, the case of a forklift with a pair of rear wheels as steering wheels has been described, but it can also be suitably implemented in a forklift with a four-wheel steering system, and can also be applied to other guided vehicles that run unmanned. It can also be applied to

Effects of the Invention As explained above, the guiding device for a guided vehicle according to this invention detects the magnetic field generated in the guiding wire with a pair of detection coils located on both sides of the guiding wire. A conveyance system that guides a vehicle to travel along a guide line by operating an actuator in accordance with the detection output of a detection coil, and using the actuator to steer and drive steering wheels via a steering link mechanism having a tie rod and a knuckle arm. In a car guidance system, the pair of detection coils are supported by tie rods or knuckle arms so as to follow the movement of the steered wheels. Derailment is prevented by moving in the direction of the guide wire, and since both detection coils are placed at the bottom of the car body, there is no interference with the car body, and there is no space between the detection coil and the guide wire. Since there is no magnetic material,
The magnetic field generated by the guide wire can be accurately detected, and it is less susceptible to disturbances, allowing accurate guidance in the running direction.

In addition, since the pair of detection coils that follow the steering wheels approach the guide line when driving around a curve, the sensitivity to deviations is high, and deviations on curves can be corrected quickly and accurately. ,
Driving performance such as high-speed running and minimum turning radius has been improved during unmanned driving around curved sections, significantly shortening transport time, and the ability to turn corners with a small radius saves the travel path of the transport vehicle. This has the effect of saving space.

[Brief explanation of the drawing]

Figures 1 to 5 show a first embodiment of this invention, in which Figure 1 is a plan view showing the steering link mechanism of the steering wheel, Figure 2 is a front view of Figure 1, and Figure 3 is a front view of Figure 1. 4 is a schematic plan view showing the operation of the steering link mechanism;
The figure is a side view showing the entire forklift, Figure 5 is a plan view of Figure 4, Figures 6 and 7 are a second embodiment, and Figure 6 is a steering link mechanism for steering wheels. FIG. 7 is a schematic plan view showing the operation of the steering link mechanism, and FIGS. 8 to 10 are explanatory diagrams of conventional examples. 30,50...Forklift, 31...Vehicle body, 34...Rear wheel (steering wheel), 36...Over beam, 37...Under beam, 40,41
...Natsukuru Arm, 42...Bellcrank, 4
3... Power steering cylinder, 44, 45... Tie rod, 46, 47, 56, 57... Detection coil, 48, 49, 58, 59... Stay, G...
Guide line, S...Steering link mechanism.

Claims (1)

[Claims for Utility Model Registration] (1) A magnetic field generated in a guide wire is detected by a pair of detection coils located on both sides of the guide wire, and an actuator is operated according to the detection output of the detection coil, and the actuator In a guide device for a guided vehicle that guides the vehicle to travel along a guide line by steering and driving a steering wheel through a steering link mechanism having a tie rod and a knuckle arm, the pair of detection coils are steered. A guide device for a conveyance vehicle, characterized in that it is supported by a tie rod or a knuckle arm so as to follow the movement of steering wheels. (2) A utility model characterized in that the pair of detection coils are attached to the lower part of a stay whose upper part is supported by a tie rod or a knuckle arm, and are arranged at the lowest part of the vehicle body so as to directly face the running road surface. A guide device for a guided vehicle according to claim 1.