JP4200785B2 - Automated guided vehicle - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an automatic guided vehicle that automatically travels along a guide line provided on a traveling road surface.
[0002]
[Prior art]
In general, the automatic guided vehicle is configured such that a front wheel in a traveling direction can freely turn around a vertical axis and a rear wheel is fixed to travel in order to stably steer the vehicle. Here, due to space restrictions, it may be necessary to retract the automatic guided vehicle without changing its direction. In such a case, the direction of the preceding rear wheel is fixed, and the following front wheel is free to turn, so that there is a problem that stable steering cannot be performed and the vehicle is deviated from the travel line.
[0003]
As a technique for solving such a problem, there is one described in Patent Document 1.
[0004]
As shown in FIG. 6, an automatic guided vehicle 40 described in Patent Document 1 includes casters 42 and 43 that are turnable around a vertical axis disposed at four corners of a vehicle body 41, and the turn of the casters 42 and 43 can be switched. And a locking mechanism 44 for locking. The lock mechanism 44 functions so as to obtain good steering performance by locking only the rear caster 43 during forward movement and locking only the front caster 42 during backward movement.
[0005]
[Patent Document 1]
JP-A-11-171010 [0006]
[Problems to be solved by the invention]
However, the automatic guided vehicle 40 must individually lock or release the casters 42 and 43 that can turn, and the lock must be performed in a state where the wheels 45 are accurately directed in the axle direction. A lock mechanism 44 that includes a stopper link 46, a stopper pin 47, and the like and that requires high accuracy must be provided for each of the casters 42 and 43. For this reason, there existed a subject that the complexity and cost increase of an apparatus will be caused.
[0007]
SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to solve the above-described problems and to provide a simple and inexpensive automatic guided vehicle that can perform stable steering in both forward and backward travel.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, the present invention has a guide wheel provided at the center of a vehicle body and supported by a drive source so as to be able to travel forward and backward in the traveling direction, and previously provided on the traveling road surface. A driving unit having driving wheel control means for reading the record of the line and controlling the steering of the driving wheel in the traveling direction and controlling the longitudinal driving, and the front traveling wheel that is supported in front of the traveling direction of the vehicle body and travels in parallel in the axle direction And a forward caster that is turnable around the vertical axis, a rear running wheel that is supported by a rear portion in the running direction of the vehicle body and travels in parallel with the axle direction, a rear caster that is turnable around the vertical axis, and the drive unit. Steering switching means for grounding the front caster and the rear traveling wheel to the traveling road surface when traveling in the direction and simultaneously moving the rear caster and the front traveling wheel away from the traveling road surface; Provided, the steering switching means, slidably disposed in the vehicle width direction together are spaced apart around the body, and a switch member for receiving a force as a signal for reversing the direction of travel from the outside of the vehicle of the pusher, The vehicle body is pivotally supported around the longitudinal axis and connected to each switch member. When one switch member is pushed in one of the vehicle width directions, the other switch member is in the vehicle width direction. A synchronizing lever that interlocks each switch member so as to slide to the other side, and is engaged with both ends of the synchronizing lever, respectively, and when one of the front and rear switch members is pushed, the pushed traveling wheel is pushed down and pushed. der that a pressing lever grounding the opposite side of the caster float the running wheels on the opposite side with floating the side of the caster, which is from the road surface .
[0009]
The driving wheel is provided at the center of the vehicle body and is supported by a driving source so as to be able to travel forward and backward in the traveling direction, and reads a record of a guide line previously provided on the traveling road surface. A drive unit having a drive wheel control means for controlling steering in the running direction and driving back and forth, a front running wheel supported in front of the running direction of the vehicle body and running in parallel to the axle direction, and a forward caster capable of turning around the vertical axis A rear traveling wheel that is supported by a rear portion in the traveling direction of the vehicle body and travels in parallel in the axial direction, a rear caster that can turn around the vertical axis, and a front caster that travels the vehicle body in one direction of traveling by the drive unit; Steering switching means for grounding the rear traveling wheel to the traveling road surface and simultaneously moving the rear caster and the front traveling wheel away from the traveling road surface, the steering switching means, A switch member provided apart from the front and rear of the body and slidable in the vehicle width direction and receiving a force as a signal for reversing the traveling direction from a pusher outside the vehicle, and a vertical axis at the center of the vehicle body Each switch member is pivotably supported and connected to each switch member. When one switch member is pushed to one side in the vehicle width direction, the other switch member slides to the other side in the vehicle width direction. A synchronizing lever that interlocks the switch member, and a wheel that is engaged with both ends of the synchronizing lever and that depresses the caster on the pressed side when either of the front and rear switch members is pressed to And a pressing lever for floating the caster on the opposite side and grounding the traveling wheel on the opposite side .
[0010]
The vehicle body is provided with a limit switch for detecting that the synchronization lever has reached a predetermined position for completing the switching of the traveling wheel, and the drive wheel control means is configured such that the limit switch displays position information of the synchronization lever. when acquired, to determine the direction to proceed from this position information, may the drive wheels Ru is a motor for rotating so that forward or reverse drive.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.
[0012]
As shown in FIGS. 1A and 4, the automatic guided vehicle 1 includes a vehicle body 2 on which a load (not shown) can be loaded, and a drive that is provided at the center of the vehicle body 2 and applies thrust to the vehicle body 2. The unit 3, casters 4 and 5 that are supported at the front and rear portions in the traveling direction of the vehicle body 2, respectively, and can be turned around the vertical axis, and are supported at the front and rear portions in the traveling direction of the vehicle body 2. The traveling wheels 6 and 7 traveling in parallel with the traveling direction) and the caster 4 in the traveling direction and the traveling wheels 7 in the traveling direction when the driving unit 3 is operated to travel the vehicle body 2 in one traveling direction. And a steering switching means 9 for moving the rear caster 5 and the front traveling wheel 6 away from the traveling road surface 8 at the same time as contacting the ground.
[0013]
The vehicle body 2 is formed by assembling a frame material into a rectangular frame shape, and the drive unit 3 is fixed at the center of the bottom. The vehicle body 2 is provided with a battery 10 for supplying power to the drive unit 3 and a control panel 11 for operating the drive unit 3 manually or remotely.
[0014]
The drive unit 3 is integrally provided at the bottom of the vehicle body 2 and accommodates a drive wheel control means 12 to be described later. The drive unit 3 is rotatable around the vertical axis at the bottom of the control box 13 and is elastically moved downward. It consists of the self-propelled part 14 provided by energizing.
[0015]
The self-propelling unit 14 includes a motor (servo motor (not shown)) as a driving source, a rotatable driving wheel 16 connected to the motor via a power transmission mechanism 15 such as a chain and a sprocket, and a traveling road surface 8 in advance. A reading unit (not shown) for reading a record of the guide wire 17 provided on the upper side. The driving wheels 16 are arranged in parallel one by one on the left and right, and each driving wheel 16 is rotationally driven by a separate motor. And it can steer by giving a rotation difference to right and left driving wheels 16 suitably. The reading unit is electrically connected to the drive wheel control unit 12 in the control box unit 13 and transmits information read from the guide wire 17 made of magnetic tape or the like to the drive wheel control unit 12. .
[0016]
The drive wheel control means 12 is specifically composed of a microcomputer, and is based on a command sent from the control panel 11, a reverse signal obtained from a limit switch 18 described later, and information obtained from the guide wire 17. By controlling the activation, stop, adjustment of the rotation speed, change of the rotation direction, and the like, the steering in the traveling direction of the drive wheels 16 is controlled and the longitudinal drive control is performed.
[0017]
The casters 4 and 5 are respectively attached to both front and rear sides of the vehicle body 2 so as to support the four corners of the vehicle body 2. Specifically, the casters 4 and 5 are rotatably supported by a plate 2 a provided at the bottom of the vehicle body 2 and extend up and down, and the casters 4 and 5 are provided at the lower end of the turning shaft 19 and rotate integrally with the turning shaft 19. And a wheel 21 provided on the wheel holder 20 so as to be rotatable about a horizontal axis. The wheel 21 is pivotally supported by the wheel holder 20 so as to be grounded at a position shifted in the horizontal direction from directly below the turning shaft 19, and always follows the turning shaft 19 when traveling.
[0018]
The traveling wheels 6 and 7 are provided between the front casters 4 and the rear casters 5 so as to be movable up and down. Specifically, the traveling wheels 6 and 7 are attached to one end side of a support lever 22 provided at the bottom of the vehicle body 2 so as to be rotatable about an axis extending in the vehicle width direction, and the support lever 22 rotates. It is designed to go up and down. Further, a counterweight 23 is provided on the other end side of the support lever 22 for floating the traveling wheels 6 and 7.
[0019]
As shown in FIGS. 1 (a) and 2, the steering switching means 9 receives the force from a pusher (not shown) outside the vehicle as a signal for reversing the traveling direction, and uses that force to reverse the direction. (Progression direction after reversal) The vehicle comprises a wheel switching link mechanism 24 that grounds the rear traveling wheel 7 to the traveling road surface 8 and allows the front traveling wheel 6 to rise.
[0020]
The wheel switching link mechanism 24 is slidable in the vehicle width direction on one side of the vehicle body 2 and is provided spaced apart in the front-rear direction to receive a force (reverse signal) from the pusher; A synchronization lever 26 that is pivotally supported around the vertical axis and interlocks with each switch member 25, and is provided at the front and rear portions of the vehicle body 2 so as to be rotatable about the horizontal axis, and has one end at the end of the synchronization lever 26. And a push-down lever 27 that pushes down one end side (the side on which the traveling wheels 6 and 7 are provided) of the support lever 22 in conjunction with the rotation of the synchronization lever 26.
[0021]
The switch member 25 is formed in a rod shape extending in the vehicle width direction, and is slidably inserted into a guide tube 28 provided on one side of the vehicle body 2 so as to extend in the vehicle width direction. The synchronization lever 26 extends from the vicinity of the front end of the vehicle body 2 to the vicinity of the rear end, and both ends of the synchronization lever 26 are connected to the respective switch members 25 so as to be rotatable about the vertical axis. Engagement holes 29 are formed at both ends of the synchronization lever 26 so as to vertically penetrate one end of the push lever 27. The engagement hole 29 is formed to have a large diameter with a sufficient margin with respect to the pressing lever 27 so as to allow the pressing lever 27 to tilt with respect to the synchronization lever 26.
[0022]
As shown in FIG. 3, the push lever 27 is formed by bending the other end side in the circumferential direction with respect to one end engaged with the synchronization lever 26, and pushes the support lever 22 at the other end. The roller 30 is rotatably provided. The push lever 27 moves up and down the roller 30 by rotating in conjunction with the rotation of the synchronization lever 26.
[0023]
As shown in FIG. 2, the vehicle body 2 is provided with a limit switch 18 for transmitting to the drive wheel control means 12 that the wheel switching link mechanism 24 has received a force from the pusher. Specifically, the limit switch 18 detects that the synchronization lever 26 has reached a predetermined position for completing the switching of the traveling wheels 6 and 7, and the driving wheel control means 12 receives this information. The direction to travel is determined, and the motor is rotated forward or backward.
[0024]
Next, the operation of this embodiment will be described.
[0025]
When the control board 11 is operated to issue a forward command to the automatic guided vehicle 1, the drive wheel control means 12 acquires the position information of the synchronization lever 26 from the limit switch 18, determines the direction to travel, and corrects each motor. Rotate or reverse drive. Thereby, the automatic guided vehicle 1 starts running. At this time, as shown in FIG. 1A, on the rear side of the vehicle body 2 in the traveling direction, the traveling wheel 7 is pushed down by the wheel switching link mechanism 24 and is grounded to the traveling road surface 8, and the caster 5 is in a floating state. On the front side, since the traveling wheel 6 is raised by the weight of the counterweight 23 and the caster 4 is in a grounded state, the automatic guided vehicle 1 stably follows the steering of the drive unit 3 and follows the guide line 17. It is possible to travel stably along.
[0026]
Further, the weight of the load loaded on the vehicle body 2 is received by the front casters 4 and the rear traveling wheels 7, and the driving wheels 16 always travel at a constant ground pressure, so that they are affected by the weight of the loads. It can be steered stably. Steering of the drive unit 3 is performed by appropriately giving a rotation difference to the left and right drive wheels 16.
[0027]
The drive wheel control means 12 stops each motor and stops the drive unit 3 when information indicating that the drive wheel control means 12 stops from the guide line 17 is obtained by arriving at the turning point.
[0028]
When the switch member 25 is pushed inward in the vehicle width direction by the pusher, the synchronization lever 26 connected to the switch member 25 rotates, and the pressing lever 27 engaged with both ends of the synchronization lever 26 rotates. To do. Accordingly, the push lever 27 that has pushed down the rear traveling wheel 7 is rotated to raise the roller 30 to allow the rear traveling wheel 7 to rise, and the front push lever 27 lowers the roller 30. Thus, the front support lever 22 is pushed and turned, and the front traveling wheels 6 are lowered all together (dashed line in FIG. 3). Then, as shown in FIG. 1B, the rear support lever 22 allows the counterweight 23 to descend, and the rear traveling wheels 7 are collectively lifted from the traveling road surface 8, and the front support lever 22 is the front. The traveling wheels 6 are pressed against the traveling road surface 8 so that all the front casters 4 are lifted from the traveling road surface 8.
[0029]
When the synchronization lever 26 reaches a predetermined position for completing the switching of the traveling wheels 6 and 7, the limit switch 18 detects this and transmits it to the drive wheel control means 12. The drive wheel control means 12 reversely rotates the motor and reverses the traveling direction of the automatic guided vehicle 1 to start traveling. Since the automatic guided vehicle 1 switches the traveling wheels 6 and 7 to be grounded as described above, only the caster 5 is grounded on the front side in the traveling direction, and only the traveling wheel 6 is grounded on the rear side. For this reason, the automatic guided vehicle 1 can stably follow the steering of the drive unit 3 and can stably travel along the guide line 17.
[0030]
As described above, the drive unit 3 provided at the center of the vehicle body 2, the traveling wheels 6 and 7 supported on the front and rear portions of the vehicle body 2 in the traveling direction, and the front and rear portions of the vehicle body 2 in the traveling direction. The casters 4 and 5 that are supported, and the front casters 4 and the rear traveling wheels 7 are grounded to the traveling road surface 8 when the vehicle body 2 travels in one direction of travel by the drive unit 3, and at the same time the rear casters 5 Since the automatic guided vehicle 1 is configured by including the steering switching means 9 for moving the front traveling wheel 6 away from the traveling road surface 8, the front and rear switching between the casters 4 and 5 and the traveling wheels 6 and 7 that are grounded can be easily performed. The automatic guided vehicle 1 that can be collectively operated by the mechanism and can be stably steered in both forward and backward traveling can be made simple and inexpensive.
[0031]
Since the casters 4 and 5 are attached to both front and rear sides of the vehicle body 2 and the traveling wheels 6 and 7 are provided to be movable up and down between the front casters 4 and the rear casters 5, respectively, the traveling wheels 6 , 7 and casters 4 and 5 can be stably switched without breaking the balance of the vehicle body 2, and can travel stably during traveling.
[0032]
The steering switching means 9 includes the wheel switching link mechanism 24 that moves the rear traveling wheel 7 to below the rear caster 5 and allows the front traveling wheel 6 to rise. 6 and 7 can be moved up and down by a simple mechanism, and the automatic guided vehicle 1 can be made simple and inexpensive.
[0033]
Further, since the wheel switching link mechanism 24 is operated using the force received from the pusher outside the vehicle, it is not necessary to provide a driving source for driving the wheel switching link mechanism 24 in the automatic guided vehicle 1. The automatic guided vehicle 1 can be made simple and inexpensive.
[0035]
Although the casters 4 and 5 are directly attached to the vehicle body 2 and the traveling wheels 6 and 7 are provided so as to be movable up and down, the traveling wheels 6 and 7 are directly attached to the vehicle body 2 and the casters 4 and 5 are movable up and down. It may be provided.
[0036]
And as shown in FIG. 5, you may provide the casters 4 and 5 in the vehicle body 31 so that raising / lowering is possible and providing the traveling wheels 6 and 7 so that raising / lowering is possible. In this case, a lever member 32 is provided at the front portion and the rear portion of the vehicle body 31 and is rotatable about an axis extending in the vehicle width direction. It is preferable that the traveling wheels 6 and 7 and the casters 4 and 5 are alternatively grounded by attaching casters 4 and 5 to the wheel. The wheel switching link mechanism 33 includes a traveling wheel pressing lever 27 for pushing down one end side of the lever member 32 (the side on which the traveling wheels 6 and 7 are attached), and the other end side of the lever member 32 (the caster 4). , 5 attached side) and a caster pressing lever 34 for pressing down. The traveling wheel push-down lever 27 and the caster push-down lever 34 may be rotated in conjunction with the synchronization lever 26 as in the above-described embodiment.
[0037]
【The invention's effect】
In short, according to the present invention, the following excellent effects can be obtained.
(1) An automatic guided vehicle capable of stable steering in both forward and backward travel can be made simple and inexpensive.
[Brief description of the drawings]
FIG. 1 is a side cross-sectional view of a state where an automatic guided vehicle according to a preferred embodiment of the present invention is cut in the vicinity of one side of a drive unit. Represents a state of traveling to the right side of the page.
FIG. 2 is a plan sectional view of the automatic guided vehicle in FIG. 1 (a) cut between a battery and a steering switching means and looked down.
FIG. 3 is an enlarged view of essential parts taken along line III-III in FIG. 2;
4 is a plan sectional view of the automatic guided vehicle of FIG. 1 (a) cut down between a steering switching means and a support lever and looking down. FIG.
FIG. 5 is a side cross-sectional view of a state in which an automatic guided vehicle showing another embodiment is cut near one side of a drive unit.
FIG. 6 is a bottom view of a conventional automatic guided vehicle.
[Explanation of symbols]
1 Automatic guided vehicle 2 Car body 3 Drive unit 4 Casters (front casters)
5 Casters (rear casters)
6 Traveling wheels (front traveling wheels)
7 Traveling wheels (rear traveling wheels)
8 Driving road surface 9 Steering switching means 12 Driving wheel control means 16 Driving wheel 17 Guide line 24 Wheel switching link mechanism (link mechanism)

Claims (3)

A driving wheel provided at the center of the vehicle body and supported by a driving source so as to be able to travel forward and backward in the traveling direction, and by reading a guide line provided in advance on the traveling road surface, the traveling direction of the driving wheel. A drive unit having a drive wheel control means for controlling the steering of the vehicle and driving the vehicle back and forth, a front running wheel supported in front of the vehicle in the running direction and running parallel to the axle direction, a forward caster capable of turning about the vertical axis, A rear traveling wheel that is supported by the rear portion of the vehicle body in the traveling direction and travels in parallel to the axle direction, a rear caster that can turn around the vertical axis, and a front caster and a rear traveling device when the vehicle body travels in one direction of traveling by the drive unit. and a steering switching means for separating moving the rear casters and the front running wheels and at the same time is grounded and wheels to road surface from the road surface, the steering switching means, vehicle A switch member that is spaced apart and is slidable in the vehicle width direction and receives a force as a signal for reversing the traveling direction from a pusher outside the vehicle, and freely rotatable around the vertical axis at the center of the vehicle body And is connected to each switch member. When one switch member is pushed to one side in the vehicle width direction, the other switch member is slid to the other side in the vehicle width direction. The interlocking lever to be interlocked and the both ends of the synchronizing lever are respectively engaged, and when the front or rear switch member is pressed, the pressed wheel is pushed down to lift the pressed caster from the traveling road surface. An automatic guided vehicle comprising: a push lever that floats the opposite traveling wheel and grounds the opposite caster . A driving wheel provided at the center of the vehicle body and supported by a driving source so as to be able to travel forward and backward in the traveling direction, and by reading a guide line provided in advance on the traveling road surface, the traveling direction of the driving wheel. A drive unit having a drive wheel control means for controlling the steering of the vehicle and driving the vehicle back and forth, a front running wheel supported in front of the vehicle in the running direction and running parallel to the axle direction, a forward caster capable of turning about the vertical axis, A rear traveling wheel that is supported by the rear portion of the vehicle body in the traveling direction and travels in parallel to the axle direction, a rear caster that can turn around the vertical axis, and a front caster and a rear traveling device when the vehicle body travels in one direction of traveling by the drive unit. Steering switching means for grounding the wheel to the traveling road surface and simultaneously moving the rear caster and the front traveling wheel away from the traveling road surface. A switch member that is spaced apart and is slidable in the vehicle width direction and receives a force as a signal for reversing the traveling direction from a pusher outside the vehicle, and freely rotatable around the vertical axis at the center of the vehicle body And is connected to each switch member. When one switch member is pushed to one side in the vehicle width direction, the other switch member is slid to the other side in the vehicle width direction. A synchronized lever to be interlocked and engaged with both ends of the synchronized lever, when one of the front and rear switch members is pushed, the pushed caster is pushed down to lift the pushed running wheel from the running road surface. An automatic guided vehicle comprising: a push lever that floats the opposite caster to ground the opposite traveling wheel . The vehicle body is provided with a limit switch for detecting that the synchronization lever has reached a predetermined position for completing the switching of the traveling wheel, and the drive wheel control means is configured such that the limit switch displays position information of the synchronization lever. 3. The automatic guided vehicle according to claim 1 or 2, wherein when it is acquired, a direction to proceed is determined from the position information, and a motor that rotationally drives the driving wheel is driven to rotate forward or backward .

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