JP2002108454A - Unmanned vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem of turning radius difference when an unmanned vehicle makes a turn with a simple configuration. SOLUTION: In this unmanned vehicle 1, a supporting shaft 9 for supporting a driving box 6 provided with driving wheels 7 is provided with a main sprocket 18, and a chain 22 is wound between the sprocket 18 and an intermediate sprocket 20 of the intermediate shaft 19 at the rear of the sprocket 18. Driven wheels 16 are provided at the rear of a bottom frame 2, and their interconnected shafts 23 are respectively provided integrally with slave sprockets 24. A chain 26 twisted at the rear of the shaft 19 one time is wound between an intermediate sprocket 21 at the lower end of the shaft 19 and the sprockets 24.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic guided vehicle for transporting various parts, products, documents, and the like unattended in factories and offices.

[0002]

2. Description of the Related Art A conventional automatic guided vehicle is shown in FIG. The automatic guided vehicle 40 is provided with drive wheels 42, 42 which are provided with a drive motor and are steered with a drive motor in front of a bottom surface of a main body 41 having a lift table or a fork at the rear, and the drive wheels 42, 42.
The support shaft 43 that rotates in conjunction with the direction of the
A fixed wheel driven wheel 44, 44 is provided behind the bottom surface of the vehicle 1 to steer the drive wheel 42 while detecting a guide line 46 on a traveling road by a forward guide sensor 45 provided in front of the main body 41. ing. When the automatic guided vehicle 40 curves, steering is performed by changing the rotational speed of the left and right drive wheels 42, 42 by a drive motor.

[0003]

In FIG. 7, the trajectory when the automatic guided vehicle 40 makes a 90 ° curve to the left is shown by a two-dot chain line. 4
Since only the wheels 2 and 42 curve along the guide line 46, a large inner wheel difference is generated between the rear driven wheels 44 and 44. Therefore, a large traveling space is required inside the guide line 46, which results in a problem in designing the traveling path, using space around the traveling path, and the like. On the other hand, it is desirable that the automatic guided vehicle 40 of such a two-wheel drive be able to retreat, but the driven wheels 44 and 4 which do not change direction are preferable.
Since 4 is on the traveling side, it is difficult to control the steering and it is difficult to realize the steering. Further, even when the driven wheels 44, 44 are replaced with freely changeable wheels, they do not always face the retreating direction when moving backward, and a large load is applied at the time of turning. It is necessary to use a drive motor having a large value, which leads to an increase in cost.

SUMMARY OF THE INVENTION An object of the present invention is to provide an automatic guided vehicle capable of eliminating a difference in inner race when making a curve with a simple structure.

[0005]

SUMMARY OF THE INVENTION In order to achieve the above object, an invention according to a first aspect of the present invention is directed to an interlocking shaft that enables a driven wheel to change its direction and that rotates the driven wheel integrally with the direction change. With the drive wheel and the driven wheel facing in the front-rear direction between the support shaft and the interlocking shaft, twisting and winding the chain once along the way to support the interlocking shaft via the chain. It is characterized in that it can be turned by the same amount in the direction opposite to the shaft, and when the direction of the drive wheel is changed, the driven wheel can be tilted by the same angle in the opposite direction to the drive wheel. In addition to the object of the first aspect, the invention described in claim 2 further includes a driving wheel provided at the rear of the main body so as to easily achieve the same retreat as at the time of forward movement without using a driving motor having a large output. A reversing guide sensor that tilts by the same angle in the direction opposite to that of the driving wheel in accordance with the change of direction is provided, and when reversing, the driving wheel can be steered while detecting the guide line by the retreating guide sensor.

[0006]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a front view of an automatic guided vehicle, and FIG.
FIG. 3 is a side view of a state where the elevator is raised, and FIG. 3 is a side view of a state where the elevator is lowered. The automatic guided vehicle 1 has a bottom frame 2 having a rectangular outer shape as a main body. A pair of columns 3 and 3 are erected near the front (the left side in FIGS. 2 and 3 is referred to as the front), and a control box 4 having a built-in control unit is provided on the front side of the columns 3 and 3 and the rear side. Are provided with horizontal elevators 5 respectively. Below the control box 4,
Drive boxes 6 each having drive wheels 7, 7 on the left and right and drive motors 8, 8 (shown in FIG. 4) for individually driving each drive wheel 7 in a chain are suspended from the lower surface of the control box 4. It is supported by a support shaft 9 so as to be horizontally rotatable. Further, a forward guide sensor 10 for detecting a guideway of the traveling path is provided in front of the drive box 6. Numerals 11 and 11 denote bumpers protruding from the front and rear of the bottom frame 2 along the short side direction.

[0007] Like the forklift and the like, the lift 5
The hydraulic cylinder 12 vertically moves between the columns 3, 3 and a pair of chains 14, 14 that are bridged over sprockets (not shown) provided on both ends of the piston rod 13 in the hydraulic cylinder 12, and perform a lifting operation. In addition, on the left and right sides below the elevator 5, the center is rotatably attached to the center, one end is attached to the base end of the elevator 5 or the support 3 of the bottom frame 2, and the other end is the bottom frame. A pair of X-links 15 and 15 are provided which can be vertically extended and contracted by sliding along the inner edge of the long side 2 or the back surface of the elevator 5 to support the elevator 5 in a horizontal posture so as to be able to ascend and descend. ing. Further, a horizontal extending piece 2a having substantially the same height as the upper surface thereof is extended from the rear edge of the bottom frame 2, and a pair of direction-changeable driven wheels 16, 16 are provided on the left and right of the extending piece 2a. , And supports the automatic guided vehicle 1 together with the drive wheels 7, 7. 17
Is a holder that is rotatably provided on the back surface of the extension piece 2a in order to increase the strength of each driven wheel 16, and that changes the direction integrally with the driven wheel 16.

On the other hand, the main sprocket 18 is
Are vertically and integrally fixed, and the lower surface of the control box 4 and the rear of the drive box 6 are also vertically interposed.
An intermediate shaft 19, to which the main shafts 0, 21 are fixed orthogonally and integrally, is rotatably suspended, and a chain is provided between the main sprocket 18 and the upper intermediate sprocket 20, which is set at the same height as the main sprocket 18. 22 are wound.
2 and 4, interlocking shafts 23, 23 for supporting the driven wheels 16, 16 project from the upper surface of the extension piece 2a of the bottom frame 2, and the interlocking shafts 23, 23 Subsprockets 24, 24 are provided horizontally and integrally with each other at the same height as the intermediate sprocket 21 below the intermediate shaft 19. Further, in the bottom frame 2, the slave sprockets 24,
24, a pair of intermediate sprockets 25, 25 having a smaller interval than the slave sprockets 24, 24 are located slightly forward.
Is provided at the same height as the slave sprocket 24 so as to be rotatable and horizontal. And 26 is the intermediate sprocket 2
1 and a chain wound between the slave sprockets 24, 24. After being wound around the intermediate sprocket 21 from the front, the chain is twisted once to pass between the intermediate sprockets 25, 25, It is wound around the slave sprockets 24 and 24 at the same time after being turned over and turned left and right. However, the twisted portion of the chain 26 is replaced by rods 27 having a small thickness in order to prevent interference between the intersecting chains 26 and a shift in the height of the chain 26 due to the intersection.

Further, a sensor sprocket 28 meshing with a chain 26 is provided at the center of the bottom frame 2 slightly forward of the intermediate sprockets 25, 25 so as to rotate in synchronism with the slave sprocket 24, and is rotatably and horizontally provided. A connecting bar 29 is integrally extended rearward on the interlocking shaft of the sensor sprocket 28 so as to dive under the extending piece 2a, and a retreating guide sensor 30 is provided at the tip of the connecting bar 29 in an orthogonal shape. . Here, since all sprockets are formed with the same diameter and the same number of teeth, respectively, when the support shaft 9 rotates, the intermediate shaft 19 rotates by the same amount via the chain 22, The rotation of the intermediate sprocket 21 accompanying the rotation causes the slave sprockets 24, 24 to rotate by the same amount via the chain 26. However, since the chain 26 is twisted once, the slave sprockets 24, 24 And in the opposite direction to the rotation of the intermediate shaft 19 by the same amount. Similarly, the intermediate sprocket 2
By one rotation, the sensor sprocket 28 meshing with the crossed chain 26 also rotates by the same amount in the direction opposite to the rotation of the support shaft 9 and the intermediate shaft 19. And
In the state of FIG. 4 in which the drive wheels 7, 7 are parallel to the front-rear direction of the automatic guided vehicle 1, the driven wheels 16, 16 and the connecting bar 29 are set so as to be parallel to the drive wheels 7, 7.

In the automatic guided vehicle 1 configured as described above, the drive motors 8, 8 operate at the same rotational speed and the drive wheels 7, 7 move forward when they synchronize and rotate.
When the number of revolutions of the line 8 changes, a curve to the left and right becomes possible.
Therefore, when the automatic guided vehicle 1 operates an operation button (not shown) provided on the control box 4, the control unit 4 detects the guide line 31 provided on the traveling path with the forward guide sensor 10 as shown in FIG. Controls the drive motors 8, 8 according to a preset program, causes the automatic guided vehicle 1 to travel along the guideline 31, and lifts and lowers the elevator 5 at a predetermined location to transport the load. Here, FIG.
As shown in (A), when the drive box 6 rotates to the left during a left curve, as described above, the support shaft 9 is rotated via the chain 22.
, The intermediate shaft 19 rotates counterclockwise by the same amount, and further rotates the slave sprockets 24, 24 via the chain 26 clockwise by the same amount in the opposite direction. Then, the secondary sprocket 2
Similarly, the interlocking shafts 23, 23 of the 4, 24 rotate rightward to incline the driven wheels 16, 16 in the opposite direction to the driving wheels 7, 7, so that the automatic guided vehicle 1 smoothly curves along the guideline 31. . In the case of a right curve, the rotation of the driving wheels 7, 7 and the rotation of the driven wheels 16, 16 as shown in FIG.
This can also be smoothly curved.

In the automatic guided vehicle 1, the sensor sprocket 28 provided behind the bottom frame 2 is
As a result, the connecting wheel 29 is rotated in the same direction as the driven sprocket 24 by the same amount, and the connecting bar 29 and the retreating guide sensor 30 are inclined at the same angle as the driven wheels 16, 16 (FIGS. 5A and 5B). The automatic guided vehicle 1 can be moved backward by reversing the rotation of the automatic guided vehicle 7. Also in this case, since the control unit controls the drive motors 8 according to the guide line 31 detected by the retreating guide sensor 30, it is possible to retreat the automatic guided vehicle 1 along a locus similar to the forward movement even in the case of a curve.

As described above, according to the automatic guided vehicle 1, the interlocking shafts 23, 23 are suspended from the driven wheels 16, 16, which can change direction, and are interposed between the support shaft 9 and the interlocking shafts 23, 23. The chain 26 is twisted once and wound on the way,
3 and 23 can be rotated by the same amount in the direction opposite to the support shaft 9 via the chain 26, and when the direction of the drive wheels 7, 7 is changed, the driven wheels 16, 16 can be tilted in the opposite direction by the same angle. Thus, traveling with four-wheel steering can be performed with a simple configuration. Therefore, as shown by the two-dot chain line in FIG. 6, the difference between the inner wheels is eliminated both in the forward and backward movements, and there is no hindrance to the design of the traveling road and the use of the surrounding space. In addition, a reversing guide sensor 30 that tilts in the opposite direction to the driving wheels 7, 7 by the same angle as the driving wheels 7, 7 change direction is provided. , 7, the driven wheels 16, 16 are steered, so that the output of the original drive motors 8, 8, including the curve, can be easily moved backward as in the forward movement without using a drive motor having a large output. It becomes feasible.

In the above embodiment, the support shaft 9 and the interlocking shaft 23
Between the hydraulic cylinder 12
The intermediate shaft 19 is not necessarily required as long as the chain can be wound directly between the support shaft 9 and the interlocking shaft 23 without any obstacle. Similarly, one chain 26 is wound between the intermediate shaft 19 and the interlocking shaft 23, but the interlocking shaft 23 is wound around the intermediate shaft (a support shaft if the intermediate shaft is omitted) by separate chains. It is also possible to turn. In the above embodiment, the reverse guide sensor 30 is provided behind the automatic guided vehicle 1 so that the vehicle can be retracted and the inner race difference at the time of a curve can be eliminated. The retreating guide sensor 30 becomes unnecessary.

On the other hand, if it does not interfere with the operation of the X-link 15, the intermediate sprocket 25 can be omitted.
In this case, the sensor sprocket 28 of the retreating guide sensor 30 may be arranged so as to rotate in synchronization with the slave sprocket 24 between the slave sprockets 24. Further, in the above embodiment, the drive box 6 is steered by the control of the drive wheels 7 and the support shaft 9 rotates following the drive box 6. However, the support shaft itself is motorized using a bevel gear or the like. The present invention can also be applied to a structure in which the steering is performed by following the drive box by rotating the drive box.

[0015]

According to the first aspect of the present invention, the interlocking shaft is suspended from a driven wheel capable of changing direction, and the chain is wound between the support shaft and the interlocking shaft to interlock. The shaft can be rotated by the same amount in the direction opposite to the support shaft via the chain, and when the direction of the drive wheel changes direction, the driven wheel can be tilted in the opposite direction to the drive wheel by the same angle. With this configuration, traveling with four-wheel steering can be performed. Therefore, the inner wheel difference at the time of the curve is eliminated, and there is no hindrance to the design of the traveling road and the use of the surrounding space. According to the second aspect of the present invention, in addition to the effect of the first aspect, a retreating guide sensor is provided at the rear of the main body, the reversing guide sensor being tilted by the same angle in a direction opposite to that of the driving wheel as the driving wheel changes direction. In some cases, the drive wheels can be steered while detecting the guide line by the retreating guide sensor, so that the same retreating as in the forward movement including the curve can be easily realized without using a driving motor having a large output.

[Brief description of the drawings]

FIG. 1 is a front view of an automatic guided vehicle.

FIG. 2 is a side view of the automatic guided vehicle in a state where an elevator is raised.

FIG. 3 is a side view of the automatic guided vehicle in a state where an elevator is lowered.

FIG. 4 is an explanatory plan view of the automatic guided vehicle.

FIG. 5A is an explanatory plan view showing a state of a left curve of the automatic guided vehicle. (B) It is a plane explanatory view showing the state of a right curve of an automatic guided vehicle.

FIG. 6 is an explanatory diagram showing a moving locus of a curve of the automatic guided vehicle.

FIG. 7 is an explanatory diagram showing a moving locus of a curve of a conventional automatic guided vehicle.

[Explanation of symbols]

1 ·········································································· Support
0 · · · forward guide sensor, 16 · · · driven wheel, 18 · · ·
Main sprocket, 19 ··· Intermediate shaft, 20, 21, 25 ·
・ Intermediate sprocket, 22, 26 ・ ・ Chain, 23 ・
-Interlocking shaft, 24-Sprocket, 30-Guide sensor for retreat, 31-Guideline.

Claims (2)

[Claims] 1. A driving wheel to be steered is provided in front of a bottom surface of a main body, and a support shaft that rotates integrally with a change of direction accompanying the steering of the driving wheel is vertically provided, and a driven wheel is provided behind the bottom surface of the main body. An automatic guided vehicle that steers the drive wheel while detecting a guide line on a traveling path by a forward guide sensor provided in front of the main body, wherein the driven wheel is capable of changing its direction, and An interlocking shaft that rotates integrally with the direction change is vertically attached to the driving wheel, and the chain is once interposed between the support shaft and the interlocking shaft while the drive wheel and the driven wheel are oriented in the front-rear direction. By twisting and winding, the interlocking shaft can be turned by the same amount in the opposite direction to the support shaft through the chain, and when changing the direction of the drive wheel, the driven wheel is connected to the drive wheel. The feature is that the same angle can be tilted in the opposite direction. Unmanned carrier. 2. A retraction guide sensor is provided at the rear of the main body, the retraction guide sensor being tilted by the same angle in a direction opposite to that of the drive wheel when the direction of the drive wheel is changed. The automatic guided vehicle according to claim 1, wherein the wheels can be steered.