JP2002283821A - Article carrying dolly - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a dolly that prevents a detecting portion thereof from being displaced even with an eccentric load that tilts a main body of the dolly, thereby ensuring accurate detection of the position of the dolly main body. SOLUTION: This article carrying dolly is provided with a dolly main body 1 that runs on a running surface F by means of a plurality of driving wheels 4a and a plurality of driven wheels 6 to transport a cargo M, a laser scanner 13 that emits a laser beam so that it strikes a plurality of reflecting bodies R and detects the laser beam reflected therefrom, and a self-position detecting device that detects the position of the dolly main body 1 based on the laser beam reflected off the plurality of reflecting bodies received by the laser scanner 13. It is characterized in that column supports 14 that support the laser scanner 13 are oscillatably erected on the dolly main body 1 and a position retaining means 22 that holds the column supports 14 in a perpendicular position with respect to the running surface F is provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an article carrier that travels automatically while detecting its own position by a laser type position detector based on a command signal from a controller.

[0002]

2. Description of the Related Art An example of this kind of article transport trolley is disclosed in Japanese Patent Application Laid-Open No. Hei 6-297927. The trolley main body is provided with a traveling drive device having front and rear drive wheels on a center line. These traveling drive devices are supported so as to be pivotable about a vertical axis. Further, on the bogie main body, driven wheels that uniformly contact the drive wheels on both the left and right sides of the drive wheels and transmit the driving force uniformly are urged downward.

[0003] The bogie body is equipped with a transfer device for loading and unloading, and a laser type position detecting device for detecting its own position. This laser type position detecting device scans a laser beam from a light emitting and receiving device in a circumferential direction, reflects the laser light to a reflector disposed near a traveling path, and reflects the reflected laser light by the light emitting and receiving device. By receiving the light, the self-position is detected from the light receiving angles of the plurality of received reflected laser lights.

[0004]

By the way, many equipments such as manufacturing equipment and storage equipment are installed near the traveling route, and the equipment is mounted on the upper part of the bogie main body so that the laser light does not interfere with these equipments. The light emitter / receiver is arranged via the support member.

[0005] However, there is a case where the carriage body is inclined because the load is biased and mounted on the transfer device. Then, in the light emitting and receiving device, since the support member has a span length, the displacement is amplified by the inclination, the relative position of the light emitting and receiving device with respect to the bogie main body is shifted, and the self-position detected by the light emitting and receiving device and the actual bogie There is a possibility that the position of the main body is shifted and the accuracy of the traveling control is reduced.

An object of the present invention is to solve the above-mentioned problems and to provide an article transporting cart capable of detecting the position of the cart body with high accuracy without displacing the detector even if the cart body is inclined. Aim.

[0007]

In order to achieve the above object, the invention according to claim 1 is directed to a carriage body for transporting a load by traveling on a traveling surface by a plurality of wheels, and detecting light to a plurality of reflectors. An article transport trolley comprising: a light emitting and receiving device for irradiating and detecting the reflected detection light thereof; and a self-position detecting device for detecting a position of the bogie main body from the reflected detection light received by the light emitting and receiving device, wherein the bogie main body is provided. Further, there is provided a posture supporting means for vertically supporting a supporting member for supporting the light emitting and receiving device, and for maintaining the posture of the supporting member perpendicular to a running surface.

[0008] According to the above construction, the column member can be held in a posture perpendicular to the running surface by the posture holding means, so that the carriage body tilts due to the movement of the center of gravity due to the load biased on the carriage body. , The support member is held in a posture perpendicular to the running surface. Therefore, the change of the position of the light emitting and receiving device due to the inclination of the bogie main body can be kept within the range that does not affect the traveling control, the self-position can be detected with high accuracy, and accurate traveling control can be performed It becomes.

According to a second aspect of the present invention, in the configuration of the first aspect, the posture holding means is constituted by a plurality of guide rollers disposed at a lower portion of the column member and grounded on the running surface. is there.

According to the above configuration, the posture of the support member can be maintained only by grounding the plurality of guide rollers, and the detection accuracy can be improved with a simple configuration. According to a third aspect of the present invention, in the configuration of the first or second aspect, the wheels are biased downward on both sides of the plurality of drive wheels disposed at front and rear positions of the center portion of the bogie main body. And a driven wheel that evenly grounds the drive wheel, and the strut member is supported by the bogie main body so as to be swingable at least around an axis in the front-rear direction.

According to the above structure, in the bogie structure in which the driving wheels are arranged at the front and rear positions of the center portion and the driven wheels are urged downward on the left and right sides to evenly contact the driving wheels with the load, The displacement of the center of gravity tends to cause tilting to the left and right, which greatly affects the position shift of the light emitting and receiving device. By supporting the support member on the bogie so that it can swing around the longitudinal axis, the right and left The inclination can be coped with, and the detection accuracy of the self-position can be further improved.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Here, an embodiment of an article transport cart according to the present invention will be described with reference to FIGS.

As shown in FIG. 3 and FIG. 6, this article transporting trolley includes a transfer device 2 having a pair of transfer fork members 2a which can move back and forth on a main body 1 of the trolley.
Travel route M based on an operation command signal transmitted wirelessly from
A plurality of stations P1 to P5 are moved from the home position HP along L to convey a load M such as a processed part.

As shown in FIG. 4, on a bottom frame 1a of the bogie body 1, a traveling device for rotating left and right driving wheels 4a by a traveling driving device (such as an electric motor) 4b at front and rear positions of a center line CL. 4F and 4B are provided. The left and right drive wheels 4a, 4a of the traveling devices 4F, 4B are separately driven to control the rotational speed difference during corner traveling and the like, and the front and rear traveling devices 4F, 4B
Each of the bottom frames 1a is rotatably supported around a vertical axis via a turning bearing 5 and is turned by a steering device (not shown). As a result, the forward and backward movement along the center line CL can be quickly changed to the traverse movement, and the front and rear drive wheels 4a, 4a turned by 90 degrees are rotated forward and reverse, so that the center O of the bogie main body 1 becomes the axis center. It is configured to be able to turn.

In the bogie main body 1, driven wheel devices 7R and 7L for biasing the driven wheels 6 downward at predetermined pressures on both left and right sides of the driven wheels 8 in order to make all the driving wheels 4a land evenly. Is provided. Further, the driven wheel devices 7R and 7L have a fixing function of fixing the driven wheel 6 to prevent the bogie main body 1 from tilting and swaying when the load M is transferred by the transfer device 2 or when traversing is started. Equipped.

That is, the driven wheel devices 7R and 7L are
As shown in FIG. 5, the bearing 7a is attached to the bottom frame 1a.
A rotatable member 7b is rotatably supported around a vertical axis via a wheel support 7d, and a wheel support 7d is attached to the rotatable member 7b via a horizontal support pin 7c so as to be vertically swingable. The driven wheel 6 is rotatably supported by the wheel support 7d. A hydraulic working cylinder (fixing means) 7f is provided on the bottom frame 1a via a mounting member so that the piston rod e moves downward and urges the wheel support 7d downward. A first coil spring (urging means) 7h for urging the wheel support 7d to rotate downward through the piston rod 7e to the extension room 7g, and a rotating member 7b
A first biasing coil spring (biasing means) 7i is provided between the wheel support 7d and the piston rod 7e, and biases the wheel support 7d downward. Further, a hydraulic pressure pipe 7m having an electromagnetic switching valve 7k interposed from a hydraulic oil tank 7j is connected to the extension chamber 7b of the working cylinder 7f. The switching valve 7k is held at the position I during normal running, so that the liquid can freely enter and exit the extension room 7g.
At the time of transfer of the load by the transfer device 2, the position is switched to the position II, the flow of the liquid into and out of the extension room 7g is stopped, the piston rod 7e is locked, and the upward movement of the driven wheel 6 is restricted.

This transport vehicle confirms the current self-position of the transport vehicle detected by the self-position detecting device 12 based on the operation command signal from the central control device 3 by the travel control device 11 and controls the traveling direction. It is configured as follows. A laser scanner (light emitting and receiving device) 13 for detecting a self-position is provided on a support member 14 at the uppermost position at the front of the carriage body 1.
It is arranged through. This laser scanner 13
Laser light (detection light) L 360 degrees horizontally around the vertical axis
t, and detects the reflected laser light (reflection detection light) Lr respectively reflected by the plurality of reflectors R disposed near the traveling route.
2, the self-position can be detected from the light receiving angle of the reflected laser light Lr.

The laser scanner 13 outputs a laser beam L
In order to avoid the obstacles of t and Lr, it is arranged on the top of the bogie main body 1 via a support member 14. In addition, if the carriage body 1 is slightly inclined due to the bias of the load M, the laser scanner 13 may be moved due to the span length (height) of the support member 14.
Is largely displaced with respect to the bogie main body 1, and in order to prevent this, a column supporting device 21 for vertically supporting the column member 14 so as to be swingable on the bogie main body 1, and a supporting surface F And a posture holding means 22 for holding the posture so as to be perpendicular to the camera.

As shown in FIGS. 1, 2, and 4, the support member 14 includes a base portion 14a and a gate-shaped frame 14b disposed on the base portion 14a so as to be movable up and down. In the support device 21, the base portion 14a is loosely fitted in a holding space portion 23 formed in the bogie main body 1. The base body 14a is supported by the bogie main body 1 so as to be swingable within a predetermined range via a horizontal pin 24 in the front-rear direction perpendicular to the horizontal direction in which the bogie main body is easily inclined. The posture holding means 22 is constituted by left and right posture holding roller devices 25 in which guide rollers 25a disposed on the left and right sides at the bottom of the base portion 14a are in contact with the running surface F. The attitude holding roller device 25 is provided with a guide roller 25a and a spherical guide roller 25a that can rotate and follow the traveling direction of the bogie main body 1 and a guide roller 25a so as not to hinder the grounding state of the drive wheel 4a. Running surface F
And a biasing member 25b such as a coil spring that is grounded.

Therefore, even if the bogie main body 1 is inclined, the guide roller 25a is grounded to the running surface F with equal pressure, and the support member 14 is set in a posture perpendicular to the running surface F with the horizontal pin 24 as a center. Since the laser scanner 13 is held, the laser scanner 13 can be held at an appropriate position, and the self-position can be accurately detected.

When the attitude of the four drive wheels 4a is normally controlled so as to be evenly grounded, the carriage body 1
When the running surface F is tilted forward and backward when the running surface F is tilted forward and backward without generating a tilt in the front and rear direction, there is no problem in detecting the self-position.

As shown in FIG. 7, an auxiliary horizontal pin 26 is attached to the bogie main body 1 at the base end side of the horizontal pin 24 and extends in the horizontal direction orthogonal to the horizontal pin 24 to support the horizontal pin 24 so as to be vertically swingable. By doing so, the guide roller 25 can be urged downward by the weight of the support member 14, and the urging member becomes unnecessary. Of course, instead of the universal joint structure using the horizontal pin 24 with the auxiliary horizontal pin 26, a spherical joint or the like may be adopted.

According to the above embodiment, the driven wheel device 7
A support member configured to urge the driven wheel 6 downward by R and 7L to ground all the drive wheels 4a evenly, and to support the laser scanner 13 even when the bogie main body is slightly inclined left and right during traveling. 14 is swingably attached to the bogie main body 1 via a horizontal pin 24 by a column supporting device 21, and a posture holding roller device 25 is provided at the bottom of the column member 14, so that the column member 14 travels by a guide roller 25a. The posture is always kept perpendicular to the plane F. Thereby, the relative position of the laser scanner 13 with respect to the carriage main body 1 does not change. Therefore, the self-position of the transport vehicle can be accurately detected, and the accuracy of travel control can be further improved.

[0024]

As described above, according to the first aspect of the present invention, since the support member can be held in a posture perpendicular to the running surface by the posture holding means, the load imbalanced on the bogie main body can be held. Due to the movement of the center of gravity, the support member is maintained in a posture perpendicular to the running surface even if the bogie main body is inclined during running. Therefore, the change of the position of the light emitting and receiving device due to the inclination of the bogie main body can be kept within the range that does not affect the traveling control, the self-position can be detected with high accuracy, and accurate traveling control can be performed It becomes.

According to the second aspect of the present invention, the posture of the support member can be maintained only by grounding the plurality of guide rollers, and the detection accuracy can be improved with a simple configuration.

According to the third aspect of the present invention, the bogie structure is such that the drive wheels are arranged at the front and rear positions of the center portion, and the driven wheels are urged downward at the left and right side portions so that the drive wheels are evenly grounded. In, the inclination of the center of gravity due to the load is likely to cause left and right inclination, which greatly affects the position shift of the light emitter and receiver, but by supporting the support member on the bogie so that it can swing around the longitudinal axis, It is possible to cope with the left and right inclination of the bogie main body, and it is possible to further improve the detection accuracy of the self-position.

[Brief description of the drawings]

FIG. 1 is a main part cross-sectional view showing an embodiment of an article transporting cart according to the present invention.

FIG. 2 is a partially exploded perspective view of the article transport cart.

FIG. 3 is a front view showing a configuration of the article transporting cart.

FIG. 4 is a plan view showing a truck main body of the article transporting truck.

FIG. 5 is a configuration diagram showing a driven wheel device of the article transporting cart.

FIG. 6 is a schematic plan view of a factory facility using the article transport cart.

FIG. 7 is a sectional view of a main part showing another embodiment of the wheel support device of the article transporting cart.

[Explanation of symbols]

 M Load F Running surface CL Center line R Reflector Lt Laser beam Lr Reflected laser beam 1 Bogie body 2 Transfer device 3 Central control device 4F, 4B Running device 4a Drive wheel 4b Travel drive device 5 Slewing bearing 7R, 7L Drive wheel device REFERENCE SIGNS LIST 11 travel control device 12 self-position detection device 13 laser scanner 14 support member 21 support support device 22 attitude holding means 23 holding space 24 horizontal pin 25 attitude holding roller device 25 a guide roller 25 b biasing member

Claims (3)

[Claims] 1. A light emitting and receiving device for irradiating a plurality of reflectors with detection light and detecting the reflected detection light on a bogie main body that conveys a load by traveling on a running surface by a plurality of wheels; An article transporting truck equipped with a self-position detecting device for detecting the position of the truck body from the reflection detection light received in the above, wherein a pillar member supporting the light emitting and receiving device is erected on the truck body in a swingable manner. An article transporting truck provided with a posture holding means for holding the posture of the support member perpendicular to a running surface. 2. The article transport trolley according to claim 1, wherein the attitude holding means comprises a plurality of guide rollers disposed below the support member and grounded on the running surface. 3. A plurality of driving wheels disposed at front and rear positions of a center portion of a bogie main body, and driven wheels urged downward on both sides of the driving wheels to evenly ground the driving wheels. The support member is supported by the bogie main body so as to be swingable at least around an axis in the front-rear direction.
Or the article transport trolley according to 2.