JPH0546083Y2 - - 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.
are arranged on both sides of the front wheel 4 and symmetrically about the front wheel 4, so that the detection coils 3a and 3b are steered together with the front wheel 4 when the steering wheel is operated. Also, in 1977-
In the transport vehicle disclosed in Japanese Patent No. 125932, as shown in FIG. 12, 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. The arm 12 is mounted so as to swing thereon, and is mounted on both sides of the tip of the arm 12.
A pair of detection coils 13a and 13b are arranged.

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, if an attempt was made to travel smoothly not only on straight sections but also on curved sections, it was not possible to increase the traveling speed on the straight sections, which caused problems 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. 13, this means that the transport vehicle 21
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 begins to travel 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 a position at a distance l from the guide line G, respectively.
As a result, the detection coil 24
The sensitivity to deviations caused by a and 24b is increased, and the train runs around curved sections without derailing.

However, in this guided vehicle guidance system, the link 23 to which the detection coils 24a and 24b are attached
a, 23b to swing without interfering with the vehicle body side, and to prevent a part of the vehicle body, which is a magnetic material, from interposing between the moving detection coils 24a, 24b and the guide wire G. In many cases, the detection coils 24a and 24b are placed at the bottom of the vehicle body due to the need to secure space. There was a problem that the installation position was too low, making it difficult to guide.

This idea was created in view of the above problems.
It is an object of the present invention to provide a guidance device for a transport vehicle in which a pair of detection coils is made to follow the movement of steering wheels being steered, and both detection coils are arranged at an appropriate height for easy guidance control.

Means for Solving the Problems The guided vehicle guiding device of this invention as a means for solving the above problems detects the magnetic field generated in the guiding wire with a pair of detection coils located on both sides of the guiding wire. A guide device for a guided vehicle that causes the guided vehicle to travel along a guide line by operating an actuator according to the detection output of the detection coil, and driving the steered wheels by the actuator via a steering link mechanism. In the vehicle, the pair of detection coils are provided in a position ahead of the steering wheels of the vehicle body so as to be movable in the width direction of the vehicle body along a guide rail disposed in the width direction of the vehicle body. The detection coil is connected to a part of the steering link mechanism by a connecting member so as to follow the movement of the steering wheel.

Effect By configuring as described above, both detection coils are arranged at appropriate heights, accurate guidance control is ensured, and when the conveyance vehicle approaches a curved part, the pair of detection coils and the guidance wire Since the distance between the vehicle and the vehicle changes, the steering wheel is steered to correct this change. When the steering wheel is steered, the detection coils connected to the steering link mechanism by the connecting member move along the guide rail in the steering direction according to the steering angle, so each detection coil is connected to the guide rail. approach each direction. As the detection coils approach each other in the direction of the guide wire, the sensitivity of each detection coil to deviation increases. Therefore, the conveyance vehicle can run smoothly at high speed along the guide line without derailing at the curved portion.

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

Figures 1 to 7 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 connected to the rear of the rear wheels 34, 34 via a connecting portion 35a. A driver's seat 31a and a steering wheel 31b for use in manned driving are provided on the upper part of the vehicle body 31.

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 power point of the bell crank 42. Also bell crank 42 no 2
One point of action includes the two tie rods 44, 4.
5, one end of one tie rod 44 is attached to the top side of the bell crank 42, and the other tie rod 44 is attached to the bottom side of the bell crank 42.
5 are rotatably connected to each other, and the other end rod ends of both tie rods 44, 45 are rotatably connected to the ends of the knuckle arms 40, 41, respectively.

On the other hand, on the rear side of the rear wheels 34, 34, a guide rail 46 having a C-shaped cross section and having a slit 46a in the longitudinal direction of the lower surface is connected to the connecting portion 35 of the counterweight 35 located behind both the rear wheels 34, 34.
The center portion is supported at the center portion a, and is provided substantially horizontally in the width direction of the vehicle body. And this guide rail 4
6, a pair of detection coils 47, 47 connected at a predetermined interval by a rod-shaped connector 47a are respectively suspended by sliders 48, 48 engaged with the slit 46, and moved in the width direction of the vehicle body. It is set freely. The slider 48 has a T-shape, and rollers 48 are provided at both ends of the T-shaped horizontal bar.
a, 48a are disposed in a rollable manner within the guide rail 46, and the detection coil 47 is attached to the lower end of a vertical bar extending downward from the slit 46a (see FIGS. 3 and 4). ).

Further, one of the pair of detection coils 47, 47 (the right side in FIG. 2) connected by the connector 47a has a guide rail 4.
The other end of a coil spring 49, which has one end locked, is connected to the end on the same side as this detection coil 47 of 6, and is always elastically biased in the return direction (rightward in FIG. 2), and the other end ( (Left side in Figure 2)
One end of a towing cable 50 is connected to the detection coil 47 of the . The tow rope 50, which has one end connected to the detection coil 47, is connected to a first pulley 51 attached to the other end of the guide rail 46 and a second pulley 51 attached to the under beam 37 near the center line of the vehicle body. 52, and the other end is connected to the bell crank 42 which connects the end of the rod 43a of the power steering cylinder 43.
is connected to the point of emphasis. And tow rope 50
The lengths of the detection coils 47, 47 are set so that when the rear wheels 34, 34 are traveling straight, the detection coils 47, 47 are located at the same distance from the center line of the vehicle body. When the power steering cylinder 43 rotates the bell crank 42 in the clockwise direction in FIG.
is moved to the left in FIG. 2 against the elastic force of the coil spring 49 and guided by the guide rail 46. Conversely, when the power steering cylinder 43 rotates the bell crank 42 in the counterclockwise direction in FIG.
0 is loosened, both detection coils 47, 47 are pulled by the elastic force of the coil spring 49, and are guided by the guide rail 46 to move to the right in FIG. Also, both the detection coils 47, 47, when moving, the over beam 36,
Under beam 37, bell crank 42, counterweight 35, and counterweight 3
It is arranged so as not to interfere with the connecting portion 35a to the vehicle body side of No.5.

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

When the forklift 30 reaches, for example, a right-hand curve, both the detection coils 47,
47, a 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 linkage S is activated by a predetermined amount. Only rotationally driven. When the bell crank 42 rotates, the tie rods 44, 45 whose one ends are connected to the bell crank 42, and the knuckle arms 40, to which the rod ends of each tie rod 44, 45 are connected.
41, both the left and right rear wheels 34, 34 are steered by a predetermined angle.

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, both the rear wheels 34, 34 are steered to a predetermined steering angle, and at the same time, the detection coil 47 is guided by a towing cable 50 whose one end is connected to the power point of the bell crank 42 driven by the power steering cylinder 43. , 47 move in the bending direction of the guide wire G at the curved portion, and as a result, the distance l between each detection coil 47 and the guide wire G becomes shorter (see FIG. 5).
At this time, both the detection coils 47, 47 move linearly while being suspended from the lower surface of the guide rail 46, so there is no need for interference or magnetic objects in the area below the guide rail 46. Since the position where the rail 46 is disposed can be selected relatively freely, both detection coils 47, 47 can be disposed at a location where the installation conditions such as the height are most compatible.

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 47,
47 moves in the direction approaching the guide wire G without interfering with the vehicle body side, and the magnetic field generated by the guide G can be detected under optimal conditions. From approaching,
The sensitivity of the detection coils 47, 47 to deviations is increased, and as a result, deviations in curved sections can be corrected quickly and accurately, improving driving performance such as high speed and minimum turning radius during unmanned driving on curved sections. improves.

Furthermore, FIGS. 8 and 10 show a second embodiment of this invention, which is different from the first embodiment in which a single tow rope with one end fixed to a bell crank is used as a connecting member. The connecting member used was two coil springs with one end of each fixed to a knuckle arm, and the same components as in the first embodiment are given the same reference numerals. , a detailed explanation thereof will be omitted.

The forklift 60 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.

The detection coils 57, 57 of the guidance device that causes the forklift 60 to run unmanned by detecting the magnetic field generated by the guidance wire G are connected together at a predetermined interval by a rod-shaped connector 57a. At the same time, it is supported by the connecting portion 35a on the rear side of the rear wheels 34, 34 and is supported by a guide rail 56 provided substantially horizontally in the width direction of the vehicle body, and is suspended by sliders 58, 58, respectively, so as to be freely movable in the width direction of the vehicle body. It is set in.

Further, the other end of each coil spring 59, whose one end is locked to the knuckle arms 40, 41, is connected to the pair of detection coils 57, 57 connected by the connector 57a.

The forklift 60 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 the magnetic field generated by the guide wire G laid on the traveling road surface is detected by a pair of detection coils 57, 57. The vehicle is steered so that the detection outputs detected by both detection coils 57, 57 are equal, and the vehicle travels unmanned along the guide line G while automatically correcting the direction of travel.

And this unmanned forklift 60
However, when it reaches a right curve, for example, the right curve is detected from the difference between the detection outputs of the two detection coils 57, 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 both left and right rear wheels 34, 34 by a predetermined angle via knuckle arms 40, 41, and the forklift 60 moves around the curved section. A guiding line G runs along it. 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
Coil spring 5 with one end locked at 0,41
9 and 59, the detection coils 57 and 57 follow the movement of the steered rear wheels 34 and 34, and are elastically pulled in the steering direction while suspended from the guide rail 56, causing the guide wire G to bend. Move in the direction of the curve (see Figure 10).

Therefore, when the forklift 60 travels on a curved portion, the rear wheels 34, 3, which are the traveling wheels,
4 is steered, both detection coils 57,
57 move in the direction closer to the guide wire G, the distance l between each detection coil 57 and the guide wire G becomes shorter, and the sensitivity to the deviation of the detection output of the detection coil 57 becomes higher, and as a result, Since deviations in curved portions are corrected quickly and accurately, driving performance such as high speed and minimum turning radius during unmanned driving on curved portions is improved.

In both of the above embodiments, the case of a forklift where the rear wheels are steering wheels has been described.
In addition to being suitable for use with four-wheel steering type forklifts, it can also be applied to other guided vehicles that run unmanned.

Effects of the invention As explained above, the guiding device for a guided vehicle according to the invention detects the magnetic field generated in the guiding wire with a pair of detection coils located on both sides of the guiding wire, and follows the detection output of the sensing coil. In the guide device for a guided vehicle, which drives the guided vehicle along a guide line by operating an actuator and driving the steered wheels by the actuator via a steering link mechanism, the pair of detection coils are connected to the vehicle body. The detection coil is installed at a position ahead of the steering wheel in the driving direction, supported by a guide rail arranged in the width direction of the vehicle body so that it can move in the width direction of the vehicle body, and both detection coils follow the movement of the steering wheel being steered. In this way, the detection coil and a part of the steering link mechanism are connected by a connecting member, and the detection coil is brought close to the guide wire when traveling around a curved portion, so that sensitivity to deviations is increased. As a result, deviations in curved areas can be corrected quickly and accurately.
Driving performance such as high speed and minimum turning radius during unmanned driving around curves has been improved, significantly shortening transport time, and the ability to turn corners with a small radius saves space on the transport vehicle's travel path. This has the effect of making it possible to

[Brief explanation of the drawing]

Figures 1 to 7 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 an enlarged view of the main part showing the installation state of the detection coil, FIG. 4 is a sectional view taken along the line - - in FIG. 3, FIG. 5 is a schematic plan view showing the operation of the steering link mechanism, and FIG. 7 is a plan view of FIG. 6, FIGS. 8 to 10 show the second embodiment, FIG. 8 is a plan view showing the steering link mechanism of the steering wheels, and FIG. The figure is a front view of figure 8, and figure 10.
The figure is a schematic plan view showing the operation of the steering link mechanism, and FIGS. 11 to 13 are explanatory diagrams of conventional examples, respectively. 30,60...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, 46,56...Guide rail, 47,5
7...Detection coil, 48, 58...Slider, 5
0...Tow rope, 59...Coil spring, G...
...guiding 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, which drives the guided vehicle along a guide line by steering and driving the steered wheels via a steering link mechanism, the pair of detection coils are connected to a point in front of the steering wheel of the vehicle body in the traveling direction. The detection coils and the steering link are provided so as to be movable in the vehicle width direction along guide rails arranged in the vehicle width direction, and the detection coils and the steering link are installed so that the detection coils follow the movement of the steered wheels. A guide device for a transport vehicle, characterized in that a part of the mechanism is connected to the vehicle by a connecting member. (2) The carrier vehicle according to claim 1, wherein the pair of detection coils are connected to each other so as to move in the width direction of the vehicle body while maintaining a constant interval during steering. induction device. (3) The guiding device for a guided vehicle according to claim 1 or 2, wherein the connecting member is a towing cable whose one end is connected to a bell crank of a steering link mechanism.