Overhead traveling vehicle system

Abstract

To provide an overhead traveling vehicle allowed to be made compact.SOLUTION: An overhead traveling vehicle system 1 is provided with: railroads R at least in part arranged in a lattice-like state; a travel part 30 traveling along the railroad R; a wheel revolving mechanism 40 revolving the travel part 30; and an overhead travel vehicle 2 placed below the railroad R and having a body part 10 suspended from the traveling body 30. The traveling part 30 includes traveling wheels 31 rolling on the railroad R around the rotation shaft as a base shaft and revolvable around a revolving shaft L30 as a base shaft. The wheel revolving mechanism 40 is arranged below the railroad R and below the travel wheels 31 to rotate the travel wheels 31.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to an overhead traveling vehicle system. [Background technology]

[0002] An overhead traveling vehicle system is known that includes tracks arranged in a grid pattern, a traveling section that travels along the tracks, and an overhead traveling vehicle that has a main body that is disposed below the tracks and suspended from the traveling section (see, for example, Patent Document 1). In such an overhead traveling vehicle system, the traveling section has traveling wheels and a direction-changing mechanism (steering drive unit) that rotates the traveling wheels around a rotating shaft. The direction-changing mechanism is provided on the top surface of the main body and includes a drive source, a pinion gear, and a rack. When the drive source rotates the pinion gear, the pinion gear moves along the rack in a circumferential direction around the rotating shaft, and the traveling wheel rotates around the rotating shaft. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 7070704 Summary of the Invention [Problem to be solved by the invention]

[0004] In the overhead traveling vehicle system described above, for example, it is necessary to place a steering drive unit between the upper surface of the main body and the track, which may result in a relatively large height dimension of the overhead traveling vehicle. Therefore, in the overhead traveling vehicle system described above, it is desirable to make the overhead traveling vehicle compact.

[0005] The present invention has been made in view of the above circumstances, and has an object to provide an overhead traveling vehicle system that allows the overhead traveling vehicle to be made compact. [Means for solving the problem]

[0006] (1) The overhead traveling vehicle system according to the present invention is The overhead traveling vehicle comprises a track at least part of which is arranged in a grid pattern, a running unit which runs along the track, a steering drive unit which turns the running unit, and an overhead traveling vehicle which has a main body which is arranged below the track and suspended from the running unit, the running unit rolls on the track around a rotation axis and includes running wheels which are rotatable around a swivel axis, and the steering drive unit is provided below the track and below the running wheels and turns the running wheels.

[0007] With this overhead traveling vehicle system, the space below the track can be effectively utilized to locate the steering drive unit. This eliminates the need to locate the steering drive unit between the top surface of the main body and the track, making it possible to reduce the height dimension of the overhead traveling vehicle. As a result, the overhead traveling vehicle can be made more compact.

[0008] (2) In the overhead traveling vehicle system described in (1) above, the traveling unit may include a traveling drive motor provided on the rotation axis of the traveling wheel. In this case, the traveling drive motor can be disposed by effectively utilizing the space above the track. This allows, for example, the height dimension from the traveling drive motor to the traveling wheel to be reduced, thereby making the overhead traveling vehicle more compact.

[0009] (3) In the overhead traveling vehicle system described in (2) above, the track has a plurality of first rails extending in a first direction and a second rail extending in a second direction perpendicular to the first direction, the first rails and the second rails being arranged in a grid pattern, the overhead traveling vehicle moves in the first direction by running a pair of first rails adjacent to each other in the second direction, and moves in the second direction by running a pair of second rails adjacent to each other in the first direction, and the overhead traveling vehicle is provided with a first sensor that acquires first information from a first mark that indicates the first information. The overhead traveling vehicle system may further include a sensor for acquiring second information from a first mark indicating second information different from the first information, and a second sensor for acquiring second information from a second mark indicating second information different from the first information. Each of the first and second rails may have a first surface facing the first sensor and on which the first mark is located, and a second surface facing the second sensor and on which the second mark is located. The second surface may be located outside the first surface and inclined toward the overhead traveling vehicle relative to the first surface when viewed from the center of a cell, which is a space surrounded by the pair of first rails and the pair of second rails in a plan view. In this case, the first and second rails forming the track are each provided with a first surface and a second surface separate from the first surface. By placing two different types of marks, one type on each surface, two different types of marks can be placed on the track. Furthermore, in an overhead traveling vehicle system with this configuration, the second surface, which is located outside the first surface when viewed from the center of the cell in a plan view, is inclined toward the overhead traveling vehicle relative to the first surface. This eliminates the need to provide the second sensor so that it projects out from the overhead traveling vehicle in order to face the second surface, thereby preventing the overhead traveling vehicle from becoming too large.

[0010] (4) In the overhead traveling vehicle system described in any one of (1) to (3) above, the traveling unit may further include a support member that axially supports the traveling wheels, and the steering drive unit may include a steering motor as a drive source, a first gear connected to an output shaft of the steering motor, and a second gear that meshes with the first gear and is connected to the support member. In this case, the support member, the first gear, the second gear, and the steering motor can be integrated into a single unit. As a result, the traveling unit can be made more compact.

[0011] (5) In the overhead traveling vehicle system described in (4) above, the steering motor may be provided so that its output shaft is parallel to the rotation axis. In this case, the steering drive unit can be configured more simply. As a result, the steering drive unit can be made more compact. [Effects of the Invention]

[0012] According to the present invention, it is possible to provide an overhead traveling vehicle system that enables the overhead traveling vehicle to be made compact. [Brief explanation of the drawings]

[0013] [Figure 1] FIG. 1 is a perspective view showing an example of an overhead traveling vehicle system according to an embodiment. [Figure 2] FIG. 2 is an exploded perspective view showing four rail units that constitute the rail assembly in FIG. 1 and a connecting member that connects them. [Figure 3] FIG. 3 is a side view showing the overhead traveling vehicle in FIG. [Figure 4] FIG. 4 is a perspective view showing the overhead traveling vehicle in FIG. [Figure 5] FIG. 5 is a perspective view showing only the track portion of the rail assembly. [Figure 6] FIG. 6 is a cross-sectional view showing a connection portion between a plurality of rail units. [Figure 7] FIG. 7 is a side view showing the running unit, the wheel turning mechanism, and the track. [Figure 8] FIG. 8 is a cross-sectional view showing the running portion. [Figure 9] FIG. 9 is a perspective view showing the running unit and the wheel turning mechanism. [Figure 10] FIG. 10 is a perspective view showing the state in which the inside of the gear box in FIG. 9 is exposed. [Figure 11] 11 is a cross-sectional perspective view showing the running unit and the wheel turning mechanism in FIG. [Figure 12] FIG. 12 is a perspective view showing an overhead traveling vehicle according to a modified example. [Figure 13] FIG. 13 is a perspective view showing a rail unit according to a modified example. [Figure 14] FIG. 14 is a schematic cross-sectional view of the first rail taken along a plane perpendicular to the X direction. DETAILED DESCRIPTION OF THE INVENTION

[0014] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the description of the drawings, the same elements are given the same reference numerals, and duplicated description will be omitted. In the drawings, for convenience of explanation, each configuration according to the embodiment is depicted with an appropriately changed scale. Some drawings also show an XYZ Cartesian coordinate system. In the following description, this coordinate system will be referenced for ease of explanation. In the following description, one direction along a horizontal plane is defined as the X direction (first direction), a direction perpendicular to the X direction and along the horizontal plane is defined as the Y direction (second direction), and the vertical direction is defined as the Z direction.

[0015] As shown in FIG. 1 , an overhead traveling vehicle system 1 according to an embodiment is a grid system (transport system) for transporting an article M by an overhead traveling vehicle 2, for example, in a clean room of a semiconductor manufacturing factory. The overhead traveling vehicle system 1 includes, for example, a plurality of overhead traveling vehicles 2 (hereinafter collectively referred to as "traveling vehicles 2"), a system controller 5 that controls the plurality of traveling vehicles 2, and a track (rail) R on which the plurality of traveling vehicles 2 travel. The traveling vehicles 2 move along the track R of the overhead traveling vehicle system 1. The traveling vehicles 2 travel along the track R and transport an article M, such as a FOUP (Front Opening Unified Pod) that houses semiconductor wafers or a reticle pod that houses reticles. The traveling vehicles 2 may also be referred to as a carriage, a transport vehicle, a transport carriage, a traveling carriage, or the like. The plurality of traveling vehicles 2 enables high-density transport of the article M, improving the transport efficiency of the article M. Note that the overhead traveling vehicle system 1 may also include only one traveling vehicle 2.

[0016] The track R is installed on or near the ceiling of a building such as a clean room. The track R is installed adjacent to, for example, a processing device, a stocker (automated warehouse), etc. The processing device is, for example, an exposure device, a coater developer, a film forming device, an etching device, etc., and performs various processes on the semiconductor wafers in the article M transported by the traveling vehicle 2. The stocker stores the article M transported by the traveling vehicle 2.

[0017] The track R is arranged in a grid pattern in a plan view (see also FIG. 5). The track R extends horizontally. In this embodiment, the track R is constructed by arranging a plurality of rail units 100, each having a first rail R1, a second rail R2, and an intersection rail R3, side by side in the X and Y directions. The overhead traveling vehicle system 1 includes a plurality of rail units 100 arranged side by side in the X and Y directions, and a plurality of connecting members 140 that connect the plurality of rail units 100 to one another. The plurality of rail units 100 and the plurality of connecting members 140 form a rail assembly 200. The rail assembly 200 is suspended from a ceiling or the like (not shown) by a plurality of hanging members H at the portions where the rail units 100 are connected to one another by the connecting members 140.

[0018] FIG. 2 is an exploded perspective view showing the four rail units 100 that make up the rail assembly 200 in FIG. 1 and the connecting members 140 that connect them. Each rail unit 100 is a rectangular parallelepiped (frame-shaped) member and has the same configuration. Each rail unit 100 includes two first rail members 110 arranged along the X direction, two second rail members 120 arranged along the Y direction, and four intersection rail members 130 arranged so that gaps are formed on extensions of the first rail members 110 and the second rail members 120 (i.e., at the intersections of the grid). When the rail unit 100 is viewed from above, the two parallel first rail members 110 and the two parallel second rail members 120 are arranged in a square shape, and the four intersection rail members 130 are arranged at the vertices of the square.

[0019] Each rail unit 100 is made of, for example, metal and is an integrated unit formed by molding the first rail member 110, the second rail member 120, and the intersection rail member 130. Each first rail member 110 includes a first beam portion 111 disposed at the upper end of the rail unit 100 and extending in the X direction, a first rail R1 disposed at the lower end of the rail unit 100 and extending in the X direction, and a first support wall 113 disposed between the first beam portion 111 and the first rail R1 and joined to the first beam portion 111 and the first rail R1. Each second rail member 120 includes a second beam portion 121 disposed at the upper end of the rail unit 100 and extending in the Y direction, a second rail R2 disposed at the lower end of the rail unit 100 and extending in the Y direction, and a second support wall 123 disposed between the second beam portion 121 and the second rail R2 and joined to the second beam portion 121 and the second rail R2. The multiple first beam portions 111 and the multiple second beam portions 121 form a lattice-like structure extending along the XY plane at the upper end position of the rail assembly 200. The first support wall 113 extends along the XZ plane. The second support wall 123 extends along the YZ plane.

[0020] The intersection rail member 130 includes an intersection support pillar 133 extending along the Z direction (vertical direction) at the position where the first beam portion 111 and the second beam portion 121 are joined at a right angle, and an intersection rail R3 provided at the lower end of the intersection support pillar 133.

[0021] As shown in FIGS. 1 and 5 , the multiple first rails R1 each extend along the X direction. The multiple second rails R2 each extend along the Y direction. The track R is formed in a grid pattern in a plan view by the multiple first rails R1 and the multiple second rails R2. The track R is formed into a plurality of squares by the multiple first rails R1 and the multiple second rails R2. The intersection rail R3 is disposed at a location corresponding to an intersection of the first rail R1 and the second rail R2. The intersection rail R3 is adjacent to the first rail R1 at a distance in the X direction and adjacent to the second rail R2 at a distance in the Y direction. The intersection rail R3 is used when the traveling vehicle 2 travels along the first rail R1, when the traveling vehicle 2 travels along the second rail R2, and when the traveling vehicle 2 travels from the first rail R1 to the second rail R2 or from the second rail R2 to the first rail R1.

[0022] Each rail unit 100 forms a square (or rectangular) track R corresponding to one square within itself. By arranging multiple rail units 100 in the X and Y directions, multiple first rails R1 extend in a row in the X direction, and multiple second rails R2 extend in a row in the Y direction. On the X-direction line, two intersection rails R3 are arranged at an interval between one first rail R1 and another first rail R1. On the Y-direction line, two intersection rails R3 are arranged at an interval between one second rail R2 and another second rail R2. The track R will be described from another perspective. Focusing on four squares consisting of two squares lined up in the X direction and two squares lined up in the Y direction, four intersection rails R3 adjacent in the X and Y directions are arranged at an interval between two first rails R1 adjacent in the Y direction and two other first rails R1 adjacent in the Y direction. Furthermore, the same four intersection rails R3 as above are arranged at intervals between two second rails R2 adjacent in the X direction and another two second rails R2 adjacent in the X direction.

[0023] In the rail assembly 200, a plurality of first rails R1, a plurality of second rails R2, and a plurality of intersection rails R3 are arranged at predetermined intervals to form a track R. A gap G corresponding to the above-mentioned interval is formed between each first rail R1 and each intersection rail R3. A gap G corresponding to the above-mentioned interval is formed between each second rail R2 and each intersection rail R3. The gap G in the track R has a constant size. Each first rail R1 includes a first running surface R1a that is flat and horizontal on its upper surface, and the running wheels 31 of the running vehicle 2 run on the first running surface R1a in the X direction (first running direction D1). Each second rail R2 includes a second running surface R2a that is flat and horizontal on its upper surface, and the running wheels 31 of the running vehicle 2 run on the second running surface R2a in the Y direction (second running direction D2). The intersection rail R3 includes an intersection running surface R3a that is flat and horizontal on its upper surface. The first running surface R1a, the second running surface R2a, and the intersection running surface R3a are all at the same height throughout the track R. The first running surface R1a, the second running surface R2a, and the intersection running surface R3a are arranged on the same or nearly the same horizontal plane.

[0024] For example, no gaps as large as the gap G are formed between the four intersecting rails R3 described above. When the traveling vehicle 2 passes through multiple rail units 100 in a straight line, the traveling wheels 31 of the traveling vehicle 2 travel on the intersecting running surfaces R3a. At that time, the traveling wheels 31 pass over any two of the four intersecting rails R3 described above. Alternatively, when the traveling vehicle 2 changes its traveling direction between the rail units 100 (changing its traveling direction by 90 degrees, i.e., when steering), the traveling wheels 31 of the traveling vehicle 2 pass over the intersecting running surfaces R3a (while changing direction).

[0025] As described above, in the rail assembly 200, a lattice-shaped track R is formed by the first rail member 110, the second rail member 120, and the intersection rail member 130. The layout of the lattice-shaped track R in the overhead traveling vehicle system 1 can be adjusted or changed as appropriate by arranging the multiple rail units 100 in any desired arrangement (including adding or deleting rail units 100).

[0026] 2 and 6, the connection structure of the rail units 100 using the connecting members 140 will be described. As shown in FIGS. 2 and 6, each connecting member 140 includes an upper connecting member 141 and a lower connecting member 142. The upper connecting member 141 is a plate-like or frame-like member extending horizontally, and is attached to the upper surface of one of the four corners of a plurality of (typically four) rail units 100. The upper connecting member 141 abuts near the intersection of the first beam portion 111 and the second beam portion 121 of each rail unit 100. The lower connecting member 142 is a plate-like or frame-like member extending horizontally, and supports the lower surface of one of the four corners of a plurality of (typically four) rail units 100. The lower connecting member 142 abuts against the intersection rail R3 of each rail unit 100.

[0027] A rod-shaped hanging member H extending in the vertical direction penetrates the upper connecting member 141 and the lower connecting member 142. The upper connecting member 141 and / or the lower connecting member 142 are fixed to the rail units 100 by fastening members (not shown) or the like, thereby connecting the rail units 100 to each other. Note that spaces 100e extending in the Z direction are formed between the rail units 100, and spaces R3e extending in the Z direction are formed between four intersection rails R3 adjacent in the X and Y directions (central portions in plan view). The hanging member H is inserted into the spaces 100e and R3e, and the upper connecting member 141 and / or the lower connecting member 142 are fixed to the hanging member H.

[0028] The overhead traveling vehicle system 1 includes a communication system (not shown). The communication system is used for communication between the traveling vehicles 2 and the system controller 5. The traveling vehicles 2 and the system controller 5 are connected to each other so as to be able to communicate with each other via the communication system.

[0029] Next, the configuration of the traveling vehicle 2 will be described with reference to FIGS. 1, 3, and 4. As shown in FIGS. 1 and 3, the traveling vehicle 2 is provided so as to be able to travel along a track R. The traveling vehicle 2 includes a traveling bogie 20 that travels on the track R, and a main body 10 that is attached to the bottom of the traveling bogie 20 and is rotatable relative to the traveling bogie 20. The traveling bogie 20 includes a bogie unit 50, for example, having a rectangular shape, that is arranged below the track R, running sections 30 that are provided at the four corners of the bogie unit 50 in a plan view and protrude upward from the bogie unit 50, and four wheel swivel mechanisms 40 that rotate each of the four traveling wheels 31 of the running section 30 relative to the bogie unit 50. The running sections 30 and the wheel swivel mechanisms 40 are integrated into a single unit. A bogie controller (controller) 8 is provided inside the bogie unit 50.

[0030] The main body 10 is disposed below the track R and suspended from the travel unit 30. As shown in FIGS. 3 and 4, the main body 10 has a main body frame 12 formed, for example, in a cylindrical shape. The main body frame 12 includes a disk-shaped top plate 12a and a cylindrical frame 12b hanging down from the periphery of the top plate 12a, and has a shape with an open bottom. The main body 10 is formed to a size that fits into one square on the track R (see FIG. 1) in a plan view. A traveling vehicle 2 can pass another traveling vehicle 2 traveling on an adjacent first rail R1 or second rail R2. The main body 10 includes a transfer device 18 disposed inside the main body frame 12. The transfer device 18 is, for example, rectangular in a plan view. The cylindrical frame 12b is open in a portion in the circumferential direction. The range in which the open portion (notch) is formed is large enough to allow the transfer device 18 to pass through. When moving horizontally, the transfer device 18 passes through the opening in the cylindrical frame 12b.

[0031] The main body 10 is attached to the bottom of the bogie unit 50 and is rotatable around a rotation axis L10 in the Z direction relative to the bogie unit 50. Traveling wheels 31 provided at the four corners of the bogie unit 50 are placed on the track R (on the first travel surface R1a, the second travel surface R2a, or the intersection travel surface R3a). The bogie unit 50 is suspended from the track R via the four traveling wheels 31 and four wheel swivel mechanisms 40. The four traveling wheels 31 allow the bogie unit 50 and the main body 10 to be stably suspended, and also allow the main body 10 to travel stably. In other words, the traveling vehicle 2 is suspended and supported by the traveling wheels 31 that travel along the track R, and moves below the track R.

[0032] The transfer device 18 moves horizontally relative to the main body 10 to transfer an article M between the load port (mounting table). The transfer device 18 is provided below the top plate 12a of the main body frame 12. The main body 10, including the transfer device 18, can rotate about a rotation axis L10 by a rotation drive unit, such as an electric motor (not shown), provided on the top plate 12a. The transfer device 18 has an article holding unit 13 that holds the article M below the track R, an elevation drive unit 14 that raises and lowers the article holding unit 13 in the vertical direction, and a slide mechanism 11 that slides the elevation drive unit 14 in the horizontal direction. The slide mechanism 11 is held on the underside of the cylindrical frame 12b. A rotation drive unit 16 is provided between the slide mechanism 11 and the elevation drive unit 14 to rotate the elevation drive unit 14 about the rotation axis L14 relative to the slide mechanism 11. The rotation drive unit 16 is provided below the slide mechanism 11, and the lift drive unit 14 is provided below the rotation drive unit 16. The article holder 13 is provided below the lift drive unit 14 via a plurality of hanging members 13b. The load port is the transfer destination or source of the traveling vehicle 2, and is the point where the article M is handed over to or from the traveling vehicle 2.

[0033] The article holding unit 13 holds the article M by suspending it by gripping the flange portion Ma of the article M. The article holding unit 13 is, for example, a chuck having claw portions 13a that can move horizontally. The article holding unit 13 holds the article M by inserting the claw portions 13a below the flange portion Ma of the article M and raising the article holding unit 13. The article holding unit 13 is connected to a hanging member 13b such as a wire or a belt.

[0034] Lifting drive unit 14 is, for example, a hoist, and lowers article holding unit 13 by paying out hanging member 13b, and raises article holding unit 13 by reeling in hanging member 13b. Lifting drive unit 14 is controlled by cart controller 8, and lowers or raises article holding unit 13 at a predetermined speed. Lifting drive unit 14 is also controlled by cart controller 8, and maintains article holding unit 13 at a target height.

[0035] The slide mechanism 11 has multiple movable plates that are stacked in the Z direction, for example. By rotating the main body 10, the slide mechanism 11 moves the rotation drive unit 16, the lift drive unit 14, and the article holder 13 attached to the lowest movable plate in any direction in a horizontal plane. The direction of movement of the movable plates in the slide mechanism 11 is determined by the rotation angle of the main body 10 relative to the cart unit 50. In the main body 10, the orientation of the transfer device 18 and the main body frame 12 is set so that the direction of movement of the movable plates coincides with the position of the opening in the main body frame 12.

[0036] The rotation drive unit 16 includes, for example, an electric motor, and rotates the lift drive unit 14 (and the article holder 13) within a predetermined angular range around a rotation axis L14 extending vertically. The angle at which the rotation drive unit 16 can rotate is, for example, any angle equal to or less than 180 degrees, but the upper limit is not limited to 180 degrees. The rotation drive unit 16 can orient the article holder 13 (or the article M held by the article holder 13) that is laterally extended in a desired direction. The slide mechanism 11 and the rotation drive unit 16 are controlled by the cart controller 8. Note that the lift drive unit 14 can be rotated by the rotation drive unit 16 even when the movable plate of the slide mechanism 11 is stored without moving (the state shown by the solid line in FIG. 3). In this case, for example, the rotation axis L14 of the lift drive unit 14 coincides with the rotation axis L10 of the main body 10.

[0037] The carriage unit 50 has a cylindrical support member (cylindrical member) 52 at its lower end. The top plate 12a of the main body frame 12 is rotatably attached to the underside of the support member 52. For example, a rotation drive unit (not shown), such as an electric motor, is provided on the top plate 12a. When the driving force of the rotation drive unit is transmitted to the support member 52, the main body frame 12 rotates around a rotation axis L10 extending vertically relative to the carriage unit 50. The rotation angle of the main body frame 12 is, for example, any angle between 360 degrees and 540 degrees, but the upper limit is not limited to 540 degrees and the lower limit is not limited to 360 degrees. The slide mechanism 11 is attached to the underside of the top plate 12a, and the top plate 12a supports the slide mechanism 11. The main body frame 12 and the transfer device 18 are integrated, and the main body frame 12 and the transfer device 18 rotate together. The traveling vehicle 2 can use the transfer device 18 to deliver the article M to and from the load port.

[0038] A cover (not shown) may be attached to the outer surface of the cylindrical frame 12b. In this case, the cover surrounds the transfer device 18 and the article M held by the transfer device 18. The cover is cylindrical with an open bottom end, and has a cutout at the portion where the movable plate of the slide mechanism 11 protrudes (the above-mentioned open portion).

[0039] The traveling unit 30 has four traveling wheels 31. Each traveling wheel 31 is provided with two auxiliary wheels 32. As shown in FIG. 4, the traveling wheels 31 are provided at the four corners of the bogie unit 50 so as to protrude upward from the top cover 51. Each traveling wheel 31 is rotatable around a horizontal or nearly horizontal axle axis along the XY plane. A traveling drive motor 33 is provided on the rotation axis L31 of each traveling wheel 31. Each traveling wheel 31 is driven to rotate by the driving force of the traveling drive motor 33. The traveling drive motor 33 is configured to be able to switch between forward and reverse rotation, for example. Each traveling wheel 31 rolls on the track R around the rotation axis L31 (see FIGS. 7 and 8). Each traveling wheel 31 rolls on the running surfaces R1a, R2a, and R3a of the first rail R1, the second rail R2, and the intersection rail R3, respectively, to cause the traveling vehicle 2 to travel. That is, the traveling unit 30 travels along the track R. Note that it is not limited to the configuration in which all of the four traveling wheels 31 are rotationally driven by the driving force of the traveling drive motor 33, and it is also possible to configure the traveling wheels 31 to be rotationally driven only in part.

[0040] Four wheel swivel mechanisms 40 (steering drive units) are fixed to a frame (not shown) inside the bogie unit 50, and a pedestal 34 is connected to each wheel swivel mechanism 40 via the pivot shaft of the wheel swivel mechanism 40. A running wheel 31, two auxiliary wheels 32, and one running drive motor 33 are attached to the pedestal 34 via a connecting unit 35 and a support unit 36 ​​(support member). For example, a square-shaped top cover 51 is provided on the top surface of the housing 53, and the pedestal 34 is disposed in notches formed in the four corners of the top cover 51. The connecting unit 35, running wheels 31, auxiliary wheels 32, and running drive motor 33 are disposed above the top cover 51.

[0041] As shown in FIGS. 3 and 4 , the connecting portion 35 connects the bogie unit 50 (more specifically, the wheel swivel mechanism 40 fixed inside the bogie unit 50) and the running wheels 31. With this connecting structure, the bogie unit 50 and the main body 10 are disposed below the track R and suspended from the running portion 30. The connecting portion 35 is formed to a thickness that allows it to pass through the gap G between the first rail R1 and the intersection rail R3 and between the second rail R2 and the intersection rail R3. The support portion 36 is provided on the upper portion of the connecting portion 35 and rotatably supports the rotation shaft of the running wheels 31 and the rotation shaft of the auxiliary wheels 32. The support portion 36 maintains the relative positions of the running wheels 31 and the auxiliary wheels 32.

[0042] As shown in FIG. 4, the traveling wheels 31 are provided so as to be rotatable about the vertically extending rotation axes L30. The four rotation axes L30 are arranged at the vertices of a square in a plan view, and the rotation axis L10 is located at the center of the rotation axes L30. In other words, the four rotation axes L30 are arranged at positions that are four-fold symmetrical with respect to the rotation axis L10 of the main body 10. In a plan view, the positions of the traveling wheels 31 and the rotation axes L30 are different (shifted). The traveling wheels 31 are rotated by the wheel rotation mechanism 40, and as a result, the traveling direction of the traveling vehicle 2 can be changed.

[0043] The auxiliary wheels 32 are arranged one in front of and one behind the running wheel 31 in the traveling direction. Each auxiliary wheel 32 is rotatable around a horizontal or nearly horizontal axle axis along the XY plane. The lower ends of the auxiliary wheels 32 are set, for example, to be higher than the lower ends of the running wheels 31. Therefore, when the running wheels 31 are traveling on the traveling surfaces R1a, R2a, and R3a, the auxiliary wheels 32 do not come into contact with the traveling surfaces R1a, R2a, and R3a. Furthermore, when the running wheels 31 pass through the gaps G between the first rail R1 and the intersection rail R3 and between the second rail R2 and the intersection rail R3, the auxiliary wheels 32 come into contact with auxiliary members (not shown) provided on the first rail R1 and the second rail R2, thereby preventing the running wheels 31 from sagging. It should be noted that the present invention is not limited to providing two auxiliary wheels 32 for one running wheel 31; for example, one auxiliary wheel 32 may be provided for one running wheel 31, or no auxiliary wheel 32 may be provided.

[0044] The wheel swivel mechanisms 40 are mechanisms for rotating the running wheels 31. The four wheel swivel mechanisms 40 are arranged, for example, at the four corners of the housing 53 of the bogie unit 50. Each wheel swivel mechanism 40 has a steering motor 43 and a driving force transmission unit 42 provided between the steering motor 43 and the running wheels 31. The driving force transmission unit 42 is fixed to a frame (not shown) inside the bogie unit 50. The driving force transmission unit 42 is connected to the base unit 34 via a swivel shaft. Each wheel swivel mechanism 40 rotates the base unit 34, the connecting unit 35, the support unit 36, the running wheels 31, the auxiliary wheels 32, and the running drive motor 33 together around the swivel shaft L30. When the running vehicle 2 is positioned at the center of each rail unit 100, each running wheel 31 is rotated 90 degrees around the swivel shaft L30. This causes the traveling wheels 31 to turn on the intersection rail R3. This allows the traveling vehicle 2 to turn. Turning means switching from a first state in which the traveling vehicle 2 travels in the first traveling direction D1 to a second state in which it travels in the second traveling direction D2, or from the second state in which the traveling vehicle 2 travels in the second traveling direction D2 to the first state in which it travels in the first traveling direction D1. The traveling vehicle 2 turns, for example, when the traveling vehicle 2 is stopped. The traveling vehicle 2 may also turn when the traveling vehicle 2 is stopped but the article M is moving (for example, turning). The driving of the wheel turning mechanism 40 is controlled by the bogie controller 8.

[0045] The bogie controller 8 performs overall control of the traveling vehicle 2. The bogie controller 8 is a computer including a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), etc. The bogie controller 8 can be configured as software in which a program stored in the ROM is loaded onto the RAM and executed by the CPU, for example. The bogie controller 8 may also be configured as hardware including electronic circuits, etc. The bogie controller 8 may be configured as a single device or multiple devices. When configured as multiple devices, these devices are connected via a communication network such as the Internet or an intranet to logically construct a single bogie controller 8. The bogie controller 8 is provided in the bogie unit 50, for example.

[0046] The carriage controller 8 controls the traveling of the traveling vehicle 2 based on the transport command. The carriage controller 8 controls the traveling of the traveling vehicle 2 by controlling the traveling drive motor 33, the steering motor 43, etc. The carriage controller 8 controls, for example, the traveling speed, operations related to stopping, and operations related to changing direction. The carriage controller 8 controls the transfer operation of the traveling vehicle 2 based on the transport command. The carriage controller 8 controls the transfer direction of the transfer device 18 by controlling the rotation (turning) of the main body 10 (main body frame 12 and transfer device 18). The carriage controller 8 controls the transfer operation of the traveling vehicle 2 by controlling the transfer device 18, etc. The carriage controller 8 controls the operation of the object grabber to grasp the item M to be placed at a specified load port, and the unloading operation to lower the held item M into the specified load port.

[0047] The system controller 5 is a computer including a CPU, a ROM, a RAM, etc. The system controller 5 can be configured as software in which a program stored in the ROM is loaded into the RAM and executed by the CPU, for example. The system controller 5 may also be configured as hardware including electronic circuits, etc. The system controller 5 may be configured as a single device or multiple devices. When the system controller 5 is configured as multiple devices, these devices are connected via a communication network such as the Internet or an intranet to logically form a single system controller 5. At least some of the various controls of the system controller 5 may be executed by the bogie controller 8.

[0048] The system controller 5 selects one of a plurality of traveling vehicles 2 capable of transporting the item M, and assigns a transport command to the selected traveling vehicle 2. The transport command includes a travel command to cause the traveling vehicle 2 to travel to the load port, and a command to grab the item M placed at the load port or a command to unload the held item M to the load port.

[0049] Next, the running unit 30 will be described in detail with reference to FIGS. 7 and 8. FIGS. 7 and 8 show an example in which the running wheel 31 runs on the intersection running surface R3a in the Y direction. FIG. 8 shows a cross section of the running unit 30 along the XZ plane. As described above, the running unit 30 has the running wheel 31, the running drive motor 33, the support unit 36, and the connecting unit 35. The running wheel 31 rolls on the track R around the rotation axis L31. The running wheel 31 swivels around the pivot axis L30. At this time, since the pivot axis L30 is located on the intersection rail R3, the running wheel 31 can swivel on the intersection rail R3. The running wheel 31 includes an outer ring portion 31a and a wheel portion 31b.

[0050] The traveling drive motor 33 is a drive source that generates a driving force for rotating the traveling wheels 31. The traveling drive motor 33 drives the traveling wheels 31. The traveling drive motor 33 is arranged so that an output shaft 33a of the traveling drive motor 33 is coaxial with the rotation axis L31 of the traveling wheels 31. The traveling drive motor 33 is provided on the rotation axis L31 of the traveling wheels 31. Specifically, when viewed from the direction along the rotation axis L31, the traveling drive motor 33 is arranged so that it overlaps with the rotation axis L31. The output shaft 33a of the traveling drive motor 33 is connected to the wheel portion 31b of the traveling wheels 31 via a connection part 37. The connection part 37 includes, for example, a reducer that reduces the rotation speed of the traveling drive motor 33, and an axle that transmits the driving force of the traveling drive motor 33 to the traveling wheels 31.

[0051] The outer diameter of the traveling drive motor 33 is smaller than the outer diameter of the traveling wheel 31. When viewed in the axial direction of the rotation axis L31, the outer shape of the traveling drive motor 33 is included in the outer shape of the traveling wheel 31. A cable Ca is electrically connected to the traveling drive motor 33. The traveling drive motor 33 is also electrically connected to the bogie controller 8, which will be described later, via the cable Ca. The traveling drive motor 33 is driven based on instructions input from the bogie controller 8, thereby driving the traveling wheel 31 to rotate.

[0052] The support portion 36 rotatably supports the running wheel 31 and the auxiliary wheel 32. In other words, the support portion 36 supports the axle of the running wheel 31 so that the running wheel 31 is rotatable in a rotational direction about the rotation axis L31. The support portion 36 supports the axle of the auxiliary wheel 32 so that the auxiliary wheel 32 is rotatable in a rotational direction about the rotation axis of the auxiliary wheel 32. In the example shown in the figure, the support portion 36 extends in the vertical direction, and rotatably supports the running wheel 31 via the connection portion 37, and also rotatably supports the auxiliary wheel 32.

[0053] The connecting portion 35 is connected to the lower portion of the support portion 36. In the illustrated example, the connecting portion 35 extends downward from the lower portion of the support portion 36 while curving inward (toward the travel drive motor 33), extends linearly downward, and then extends so as to curve outward (toward the travel wheels 31). A cable Ca is arranged along the connecting portion 35. For example, when the traveling vehicle 2 travels on the first rail R1 and crosses the second rail R2, or when the traveling vehicle 2 travels on the second rail R2 and crosses the first rail R1, the connecting portion 35 and the cable Ca pass through the gap G and extend downward from above the track R (see FIG. 7). The base portion 34 is a substantially rectangular parallelepiped portion that is continuous with the lower portion of the connecting portion 35 (see FIG. 4). For example, the base portion 34 is fixed at its upper end to a swivel cylinder 48.

[0054] 2 and 8, a first support wall (support wall) 113 is connected to the upper surfaces of the plurality of first rails R1, and a second support wall (support wall) 123 is connected to the upper surfaces of the plurality of second rails R2. A first cutout portion K1 is formed in the first support wall 113 and the second support wall 123. The first cutout portion K1 allows the traveling part 30 to pass through when the traveling vehicle 2 is traveling. For example, the first cutout portion K1 and the second cutout portion K2 allow the traveling wheel 31 and the traveling drive motor 33 to pass through.

[0055] The first cutout portion K1 of the first support wall 113 has a shape formed by cutting out an end portion of the first support wall 113 in the X direction so that the end portion opens outward in the X direction, as viewed from the Y direction. The first cutout portion K1 of the second support wall 123 has a shape formed by cutting out an end portion of the second support wall 123 in the Y direction so that the end portion opens outward in the Y direction, as viewed from the X direction. The first cutout portion K1 includes a first portion K11 and a second portion K12. The first portion K11 and the second portion K12 are continuous with each other. The first portion K11 allows passage of a portion of the traveling drive motor 33 on the side opposite to the traveling wheel 31 side. The second portion K12 allows passage of other portions of the traveling drive motor 33, the connection portion 37, the support portion 36, the traveling wheel 31, and the auxiliary wheel 32.

[0056] A second cutout portion K2 is formed on the side of the intersection support pillar 133. The second cutout portion K2 allows the running wheel 31 and the auxiliary wheel 32 to pass through. The second cutout portion K2 has a shape formed by cutting out so as to open on the side of the first support wall 113 or the second support wall 123. The second cutout portion K2 is formed so as to be continuous with the first cutout portion K1. The second cutout portion K2 may also be omitted.

[0057] Next, the wheel turning mechanism (steering drive unit) 40 will be described in detail with reference to Fig. 7 and Figs. 9 to 11. As shown in Fig. 7, the wheel turning mechanism 40 is provided below the track R and below the traveling wheels 31. As shown in Figs. 9 to 11, the driving force transmission unit 42 of the wheel turning mechanism 40 is a mechanism that transmits the driving force generated in the steering motor 43 to the traveling unit 30. The driving force transmission unit 42 has a gear box 44, a housing 45, and a swivel cylinder 48. The gear box 44 is provided below the base unit 34. The housing 45 is disposed below the gear box 44. A fixing member 45a is provided on the side of the housing 45. The housing 45 is fixed to a frame 54 in the bogie unit 50 via the fixing member 45a (see Fig. 7).

[0058] The swivel cylinder 48 has, for example, a cylindrical shape. The swivel cylinder 48 has a swivel axis L30 as its axial direction and passes through the gear box 44 and the housing 45. The swivel cylinder 48 is provided so as to be rotatable relative to the gear box 44 and the housing 45 around the swivel axis L30 as a base axis. The base 34 is connected to the upper end of the swivel cylinder 48. The lower end of the swivel cylinder 48 protrudes downward from the housing 45. A slip-out prevention member 49 is provided at the lower end of the swivel cylinder 48. The outer diameter of the slip-out prevention member 49 is larger than the outer diameter of the through-hole in the housing 45 through which the swivel cylinder 48 passes. This prevents the swivel cylinder 48 from slipping out upward.

[0059] The steering motor 43 of the wheel turning mechanism 40 is a drive source that generates a driving force for turning. The steering motor 43 is disposed below the gear box 44. The steering motor 43 is fixed to a housing 45. An output shaft 43b of the steering motor 43 is arranged so as to be parallel to the turning axis L30. The output shaft 43b is connected to the driving force transmission unit 42.

[0060] As shown in FIGS. 10 and 11 , the gearbox 44 has a first gear 46, a second gear 47, and a bearing 43c therein. The first gear 46 is, for example, a spur gear. The first gear 46 is arranged with its axial direction aligned with the vertical direction. The first gear 46 is coaxially connected to the output shaft 43b of the steering motor 43. The second gear 47 is, for example, a sector gear. The second gear 47 is arranged with its axial direction aligned with the rotation axis L30. The second gear 47 meshes with the first gear 46. The second gear 47 is engaged with the outer peripheral surface of the swivel tube 48 in the direction of rotation about the rotation axis L30. For example, a cylinder to which the inner peripheral surface of the second gear 47 is fixed can rotate in the direction of rotation about the rotation axis L30, and the inner peripheral surface of this cylinder and the outer peripheral surface of the swivel tube 48 can rotate synchronously so as to be integrated in the rotation direction via a keyway. As a result, the second gear 47 is connected to the support portion 36 via the swivel cylinder 48, the base portion 34, and the connecting portion 35. The bearing 43c rotatably supports the output shaft 43b of the steering motor 43. The bearing 43c is disposed below the first gear 46.

[0061] In the wheel swivel mechanism 40 configured as described above, when the traveling wheels 31 are swiveled, first, a driving force is generated in the steering motor 43 and transmitted to the first gear 46 via the output shaft 43b. As a result, the first gear 46 rotates, and the second gear 47 meshing with the first gear 46 rotates about the swivel axis L30. In synchronization with the rotation of the second gear 47, the swivel cylinder 48 rotates, for example, 90 degrees about the swivel axis L30. As a result, the base portion 34, the connecting portion 35, and the support portion 36 rotate 90 degrees about the swivel axis L30, and the traveling wheels 31 swivel 90 degrees about the swivel axis L30.

[0062] Note that a guide roller that abuts against the side of the crossing rail R3 may be provided between the traveling wheel 31 and the wheel turning mechanism 40 (for example, near the connecting portion 35). The guide roller prevents the traveling carriage 20 (traveling vehicle 2) from shifting position relative to the track R.

[0063] The traveling vehicle 2 is equipped with a position detection unit (not shown) that detects position information. The position detection unit detects the current position of the traveling vehicle 2 by detecting a position marker that indicates position information provided on the track R, for example. The position detection unit detects the position marker in a non-contact manner.

[0064] As described above, in the overhead traveling vehicle system 1 of this embodiment, the wheel turning mechanism 40 can be arranged by effectively utilizing the space below the track R. Specifically, the wheel turning mechanism 40 can be arranged in the dead space below the track R and below the traveling wheels 31. This eliminates the need to arrange the wheel turning mechanism 40 between the top cover 51 of the bogie unit 50 and the track R, and the dimension of the traveling vehicle 2 in the height direction can be reduced. As a result, the traveling vehicle 2 can be made more compact.

[0065] In the overhead traveling vehicle system 1 of this embodiment, the traveling unit 30 includes a traveling drive motor 33 provided on the rotation axis of the traveling wheel 31. In this case, the traveling drive motor 33 can be arranged by effectively utilizing the space above the track R. This makes it possible to reduce the height dimension from the traveling drive motor 33 to the traveling wheel 31, for example, and make the traveling vehicle 2 more compact. As a result, the overhead traveling vehicle system 1 can be made a more compact system.

[0066] In the overhead traveling vehicle system 1 of this embodiment, it is possible to increase the diameter of the traveling wheels 31. As a result, the traveling of the traveling vehicle 2 becomes more stable, and the traveling vehicle 2 can carry a heavier load (the load-bearing capacity of the traveling vehicle 2 is improved). In addition, the traveling wheels 31 can overcome the gap G more reliably.

[0067] In the overhead traveling vehicle system 1 of this embodiment, the traveling unit 30 includes a support unit 36 ​​that pivotally supports the traveling wheels 31, and the wheel swivel mechanism 40 includes a steering motor 43 as a drive source, a first gear 46 connected to an output shaft 43b of the steering motor 43, and a second gear 47 that meshes with the first gear 46 and is connected to the support unit 36. In this case, the support unit 36, the first gear 46, the second gear 47, and the steering motor 43 can be unitized. As a result, the wheel swivel mechanism 40 can be made more compact. Furthermore, since the wheel swivel mechanism 40 can be unitized, the productivity of the wheel swivel mechanism 40 is improved, and replacement and inspection of the wheel swivel mechanism 40 are made easier.

[0068] In the overhead traveling vehicle system 1 of this embodiment, the first gear 46 and the second gear 47 are provided inside the gear box 44, not in the top cover 51 of the bogie unit 50. Therefore, compared to a structure in which gears such as rack gears are provided directly on the main body 10, it is possible to suppress friction between the gears caused by vibrations during traveling, etc.

[0069] In the overhead traveling vehicle system 1, the connecting part 35 and the cable Ca pass through the gap G, for example, when the traveling vehicle 2 travels on the first rail R1 and crosses the second rail R2, or when it travels on the second rail R2 and crosses the first rail R1. Since there is no need to provide the connecting part 35 with a transmission mechanism such as a belt that transmits driving force to the traveling wheels 31, it is possible to increase the strength of the connecting part 35, etc.

[0070] Furthermore, since the overhead traveling vehicle system 1 does not require a transmission mechanism such as a belt between the traveling drive motor 33 and the traveling wheels 31, the following effects are achieved: Backlash can be reduced and rigidity can be improved. Stop position accuracy can be improved. The size of the guide roller can be increased. The structure can be simplified and productivity can be improved.

[0071] Furthermore, the running unit 30 is provided above the track R, not on the top cover 51 of the bogie unit 50. The wheel turning mechanism 40 is provided inside the housing 53 of the bogie unit 50, not on the top cover 51 of the bogie unit 50. This makes it possible to add other components to the top cover 51 of the bogie unit 50. For example, it is possible to provide a cell recognition sensor S1 on the top cover 51 of the bogie unit 50 (FIG. 13). Furthermore, for example, it is possible to provide a position recognition sensor S2 inside the housing 53, and for the position recognition sensor S2 to recognize the position recognition mark M2 through the cutout 51 a. Details will be explained in a modified example described later.

[0072] [Variations] Although the embodiments have been described above, one aspect of the present invention is not limited to the above-described embodiments, and various modifications are possible without departing from the spirit of the invention.

[0073] The overhead traveling vehicle system 1 of the above embodiment may be configured as follows. That is, in the overhead traveling vehicle system 1, the track R has a plurality of first rails R1 extending in the X direction and second rails R2 extending in the Y direction, and the first rails R1 and second rails R2 are arranged in a grid pattern. The traveling vehicle 2 moves in the X direction by the traveling unit 30 traveling on a pair of first rails R1 adjacent in the Y direction, and moves in the Y direction by the traveling unit 30 traveling on a pair of second rails R2 adjacent in the X direction. The traveling vehicle 2 has a cell recognition sensor S1 that acquires first information from a cell recognition mark M1 that indicates first information, and a position recognition sensor S2 that acquires second information from a position recognition mark M2 that indicates second information that is different from the first information. Each of the first rail R1 and the second rail R2 may have a first surface 61 facing the cell recognition sensor S1 and on which a cell recognition mark M1 is arranged, and a second surface 62 facing the position recognition sensor S2 and on which a position recognition mark M2 is arranged, the second surface 62 being arranged outside the first surface 61 when viewed from the center of the cell C, which is the space surrounded by the pair of first rails R1 and the pair of second rails R2 in a plan view, and inclined toward the overhead traveling vehicle 2 with respect to the first surface 61. In this case, the first rail R1 and the second rail R2 forming the track R are each provided with the first surface 61 and the second surface 62 separate from the first surface 61, so that at least two different types of marks can be arranged on each surface, thereby making it possible to arrange at least two different types of marks at the same position in the traveling direction of the track R. Furthermore, in the overhead traveling vehicle system 1 having this configuration, the second surface 62, which is arranged on the outside of the first surface 61 when viewed from the center of the cell C in a plan view, is arranged so as to be inclined toward the traveling vehicle 2 relative to the first surface 61. This eliminates the need to provide the position recognition sensor S2 so that it protrudes from the traveling vehicle 2 in order to face the second surface 62, thereby preventing the traveling vehicle 2 from becoming larger. Such an overhead traveling vehicle system 1 may be configured as follows.

[0074] FIG. 12 is a perspective view showing a traveling vehicle 2 according to a modified example. As shown in FIG. 12, the traveling vehicle 2 includes one cell recognition sensor (first sensor) S1 and four position recognition sensors (second sensors) S2. Note that, in the example of FIG. 11, only three of the four position recognition sensors S2 are shown. The cell recognition sensor S1 and the position recognition sensor S2 are provided in the housing 53 of the bogie unit 50. The cell recognition sensor S1 is disposed so that its detection direction faces upward substantially perpendicular to the top cover 51. The position recognition sensor S2 is disposed so that its detection direction faces substantially upward. More specifically, the position recognition sensor S2 is disposed so that its detection direction faces in a direction tilted outward as viewed from the center of the cell C with respect to the Z direction.

[0075] A cell recognition mark (first mark) M1 and a position recognition mark (second mark) M2 are arranged on the track R (see FIG. 13). The cell recognition sensor S1 detects the cell recognition mark M1 arranged on the track R in a non-contact manner. The position recognition sensor S2 detects the position recognition mark M2 arranged on the track R in a non-contact manner. The position recognition sensor S2 detects the position recognition mark M2 through a notch 51a provided in the top cover 51. The cell recognition mark M1 and the position recognition mark M2 will be described in detail later.

[0076] The cell recognition sensor S1 faces the cell recognition mark M1 when the traveling vehicle 2 is located at a predetermined position in the cell C (when the traveling vehicle 2 is stopped or traveling). At this time, the cell recognition sensor S1 acquires information (first information) about the cell C from the cell recognition mark M1.

[0077] The position recognition sensor S2 is arranged so as to face each of the second surfaces 62 (see FIG. 8) on which the position recognition marks M2 are arranged on each of the pair of first rails R1 included in the rail unit 100 when the traveling vehicle 2 moves in the X direction. In addition, the position recognition sensor S2 is arranged so as to face each of the second surfaces 62 on which the position recognition marks M2 are arranged on each of the pair of second rails R2 included in the rail unit 100 when the traveling vehicle 2 moves in the Y direction. The position recognition sensor S2 acquires position information (second information) on the track R from the position recognition marks M2.

[0078] Fig. 13 is a perspective view showing a rail unit 100 according to a modified example. Fig. 14 is a schematic cross-sectional view of the first rail R1 when cut along a plane perpendicular to the X direction. The example of Fig. 13 shows one rail unit 100 as viewed from the negative side in the Z direction. Each of the first rail R1 and second rail R2 included in the rail unit 100 has a first surface 61 and a second surface 62.

[0079] The first rail R1 will now be described. In this modification, the first surface 61 is perpendicular to the Z direction. The first surface 61 is parallel to the first running surface R1a in the Z direction. The shape of the first surface 61 is a rectangle extending in the X direction in a plan view. The first surface 61 is formed to face the cell recognition sensor S1 of the traveling vehicle 2. The first surface 61 is formed so that the traveling vehicle 2 can travel in the X direction with the cell recognition sensor S1 of the traveling vehicle 2 facing it.

[0080] A cell recognition mark M1 indicating information about the cell C is arranged on the first surface 61. It can also be said that the cell recognition mark M1 indicates information about which cell is which among the multiple cells C formed by the track R. The information about the cell C may be an ID that uniquely identifies the cell C, or may be information about the position of the cell C. In this modified example, the cell recognition mark M1 is composed of one barcode Ba. In the example of FIG. 13, the barcode Ba is arranged in the center of the first rail R1 (first surface 61) in the X direction. The cell recognition mark M1 faces the cell recognition sensor S1 when the traveling vehicle 2 is located at a predetermined position within the cell C, and the cell recognition sensor S1 acquires information about the cell C from the cell recognition mark M1.

[0081] In this modification, the predetermined position refers to the cell center. A state in which the traveling vehicle 2 is located at the cell center within the cell C refers to a state in which the bogie unit 50 is not misaligned horizontally with respect to the cell C and is not misaligned rotationally with respect to the cell C. "The bogie unit 50 is not misaligned horizontally with respect to the cell C" refers to the state in which the center of the bogie unit 50 and the center of the cell C coincide in a planar view. "The bogie unit 50 is not misaligned rotationally with respect to the cell C" refers to the state in which, of the four sides of the rectangular bogie unit 50, two sides extending in the X direction are parallel to the pair of first rails R1 that constitute the cell C, and two sides extending in the Y direction are parallel to the pair of second rails R2 that constitute the cell C in a planar view. Note that the center of the first rail R1 or the center of the cell C does not need to be strictly the center or center, and may have a certain width.

[0082] The second surface 62 is disposed outside the first surface 61 when viewed from the center of the cell C. The second surface 62 is inclined toward the traveling vehicle 2 (vertically downward in the example of FIG. 13) relative to the first surface 61. The shape of the second surface 62 is a rectangle extending in the X direction when viewed from a direction perpendicular to the second surface 62. The second surface 62 is formed to face the position recognition sensor S2 of the traveling vehicle 2. The second surface 62 is formed so that the traveling vehicle 2 can travel in the X direction with the position recognition sensor S2 of the traveling vehicle 2 facing the second surface 62.

[0083] A position recognition mark M2 indicating position information on the track R (first rail R1) is arranged on the second surface 62. The position information on the first rail R1 may be information regarding the position on the first rail R1 in the X direction, or information regarding the distance from the center of the first rail R1 (the center of the cell) in the X direction. The information indicated by the position recognition mark M2 is different from the information indicated by the cell recognition mark M1. In this modification, the position recognition mark M2 is composed of a plurality of barcodes Bb (14, for example) arranged in the X direction. The plurality of barcodes Bb are arranged without gaps on the second surface 62 along the X direction. The position recognition mark M2 faces the position recognition sensor S2 when the traveling vehicle 2 is traveling or stopped along the first rail R1, and the position recognition sensor S2 acquires position information on the first rail R1 from the position recognition mark M2.

[0084] Next, the second rail R2 will be described. In this modification, the configuration of the second rail R2 is the same as the configuration of the first rail R1. Therefore, descriptions that overlap with the above-described first rail R1 will be omitted as appropriate.

[0085] On the second rail R2, the first surface 61 is parallel to the second running surface R2a (see FIGS. 1, 2, and 5) in the Z direction. The shape of the first surface 61 is a rectangle extending in the Y direction in a plan view. The first surface 61 is formed so that the running vehicle 2 can run in the Y direction with the cell recognition sensor S1 facing it. A barcode Ba, which is the cell recognition mark M1, is arranged on the first surface 61. In the example of FIG. 13, the barcode Ba is arranged in the center of the second rail R2 (first surface 61) in the Y direction.

[0086] The second surface 62 has a rectangular shape extending in the Y direction when viewed from a direction perpendicular to the second surface 62. The second surface 62 is formed so that the traveling vehicle 2 can travel in the Y direction with the position recognition sensor S2 of the traveling vehicle 2 facing it. A position recognition mark M2 is arranged on the second surface 62. The position information on the second rail R2 may be information about the position on the second rail R2 in the Y direction, or may be information about the distance from the center of the second rail R2 (the center of the cell) in the Y direction. In this modification, the position recognition mark M2 is composed of a plurality of barcodes Bb (14 barcodes, for example) arranged in the Y direction. The plurality of barcodes Bb are arranged on the second surface 62 along the Y direction with no gaps between them. The position recognition mark M2 faces the position recognition mark M2 when the traveling vehicle 2 is traveling or stopped along the second rail R2, and the position recognition sensor S2 acquires position information on the second rail R2 from the position recognition mark M2.

[0087] The bogie controller 8 acquires the detection result of the cell recognition sensor S1. Specifically, the bogie controller 8 acquires information on the cell C acquired by the cell recognition sensor S1. Furthermore, the bogie controller 8 identifies the cell C in which the traveling vehicle 2 is located based on the information on the cell C.

[0088] The bogie controller 8 acquires the detection result of the position recognition sensor S2. Specifically, the bogie controller 8 acquires position information acquired by the position recognition sensor S2. Furthermore, the bogie controller 8 derives the amount of deviation between a predetermined position in the cell C and the stopping position of the traveling vehicle 2 based on the position information. The amount of deviation includes the amount of deviation in the horizontal direction (X direction and Y direction) as well as the amount of deviation in the rotational direction around the Z direction.

[0089] The amount of deviation in the X direction can be derived, for example, by performing a predetermined calculation process using position information acquired by at least one of the two position recognition sensors S2 facing the second surface 62 of the first rail R1 and pre-stored position information of the center of cell C. The amount of deviation in the X direction can also be derived by pre-storing a table in which the relationship between the position information indicated by the position recognition mark M2 and the amount of deviation is associated with each other, and performing a read process to read from the table the amount of deviation corresponding to the position information indicated by the position recognition mark M2 acquired by the position recognition sensor S2. The amount of deviation in the Y direction can also be derived by the above calculation process or read process, similar to the amount of deviation in the X direction.

[0090] The amount of deviation in the rotation direction around the Z direction can be derived by performing a predetermined calculation process using four pieces of position information acquired from two position recognition sensors S2 facing the second surface 62 of the first rail R1 and two position recognition sensors S2 facing the second surface 62 of the second rail R2, for example. The amount of deviation in the rotation direction around the Z direction can be calculated using at least the above three pieces of position information. The amount of deviation in the rotation direction around the Z direction can also be derived by pre-storing a table in which the relationship between each piece of position information and the amount of deviation for the four rails that make up one cell C is associated and stored, and then performing a read process to read from the table the amount of deviation corresponding to the three pieces of position information acquired by the position recognition sensors S2.

[0091] The carriage controller 8 may control the travel distance of the traveling vehicle 2 in the X direction and the Y direction by controlling the traveling unit 30. Specifically, the carriage controller 8 may control the drive distance of the traveling drive motor 33 that drives the traveling wheels 31 included in the traveling unit 30. The carriage controller 8 controls the traveling unit 30 based on the amount of deviation in the horizontal direction so that the traveling vehicle 2 moves to the predetermined position.

[0092] In the above-described modified example, a bogie controller 8 is provided to control the traveling vehicle 2. One of the two different types of marks is a position recognition mark M2 that indicates position information on the track R. The position recognition sensors S2 facing the position recognition marks M2 are arranged so as to face each of the position recognition marks M2 arranged on each of the pair of first rails R1 when the traveling vehicle 2 moves in the X direction. The position recognition sensors S2 are also arranged so as to face each of the position recognition marks M2 arranged on each of the pair of second rails R2 when the traveling vehicle 2 moves in the Y direction. The position recognition sensors S2 are four position recognition sensors S2 that acquire position information from the position recognition marks M2. The bogie controller 8 derives the amount of deviation between a predetermined position in the cell C and the stopping position of the traveling vehicle 2 based on the position information acquired by the position recognition sensors S2. In this case, the bogie controller 8 can detect the position deviation when the traveling vehicle 2 is stopped.

[0093] In the above modification, an example has been described in which the traveling vehicle 2 holds the article M below the track R. However, the traveling vehicle 2 may hold the article M above the track R. In this case, the carriage unit 50 is disposed above the traveling section 30. The cell recognition sensor S1 is disposed, for example, so as to face downward and substantially perpendicular to the underside of the carriage unit 50. The position recognition sensor S2 is disposed, for example, so as to face substantially downward. The position recognition sensor S2 is disposed so as to face in a direction tilted outward relative to the Z direction when viewed from the center of the cell C. Furthermore, the first surface 61 is disposed so as to be perpendicular to the Z direction and face upward, and the second surface 62 is disposed so as to be tilted toward the traveling vehicle 2 relative to the first surface 61 (for example, vertically upward in the example of FIG. 13). As a result, the cell recognition sensor S1 faces the cell recognition mark M1 disposed on the first surface 61, and the position recognition sensor S2 faces the position recognition mark M2 disposed on the second surface 62.

[0094] In the above modification, the cell recognition mark M1 is described as being provided at the center of the first rail R1 in the X direction and at the center of the second rail R2 in the Y direction. However, the position of the cell recognition mark M1 may be arranged along the extension direction, for example, similar to the position recognition mark M2, and the installation position of the cell recognition mark M1 is not particularly limited as long as it can be detected by the cell recognition sensor S1.

[0095] In the above modified example, the case where the cell recognition mark M1 is arranged on the first surface 61 and the position recognition mark M2 is arranged on the second surface 62 has been described, but the arrangement of the marks may be reversed. That is, the cell recognition mark M1 may be arranged on the second surface 62 and the position recognition mark M2 may be arranged on the first surface 61.

[0096] In the above modification, the case where four position recognition sensors S2 are provided on the traveling vehicle 2 has been described, but the number of position recognition sensors S2 can be changed as appropriate.

[0097] In the above-described modified example, barcodes have been used as examples of the cell recognition mark M1 and the position recognition mark M2, but they may also be two-dimensional codes such as QR Code (registered trademark). In this case, a barcode reader capable of reading two-dimensional barcodes may be used instead of the barcode reader capable of reading barcodes employed as the cell recognition sensor S1 and the position recognition sensor S2. Furthermore, instead of or in addition to the above codes, characters, symbols, figures, colors, and other displays (marks) identifiable by the cell recognition sensor S1 and the position recognition sensor S2 may be used as the cell recognition mark M1 and the position recognition mark M2. In this case, cameras or the like may be used as the cell recognition sensor S1 and the position recognition sensor S2.

[0098] In the above embodiment, the four pivot axes L30 of the traveling unit 30 and the wheel turning mechanism 40 are arranged at the vertices of a square in a plan view, but the arrangement of the pivot axes L30 does not have to be square. In a plan view, the positions of the traveling wheels 31 and the pivot axes L30 may coincide with each other.

[0099] In the above embodiment, the travel drive motor 33 is arranged so that the output shaft 33a of the travel drive motor 33 is coaxial with the rotation axis L31, but this is not limiting. As long as the travel drive motor 33 is arranged on the rotation axis L31, the output shaft 33a may be configured to be offset from the rotation axis L31.

[0100] In the above embodiment, the case where the running wheels 31 rotate on the intersection rail R3 has been described, but when turning by each wheel turning mechanism 40, each running wheel 31 may transfer from the first running surface R1a to the second running surface R2a, or from the second running surface R2a to the first running surface R1a.

[0101] In the above embodiment, the traveling vehicle is an overhead traveling vehicle, but the traveling vehicle may be a tracked vehicle that travels on a track installed on the ground. In the above embodiment, a grid system is used as the overhead traveling vehicle system 1, but the overhead traveling vehicle system 1 is not limited to a grid system. For example, an AGV (Automated Guided Vehicle) may be used as the overhead traveling vehicle system, or various known systems that travel on a grid-like traveling path may be used.

[0102] The components in the above embodiments and modifications are not limited to the materials and shapes described above, and various materials and shapes can be applied. The components in the above embodiments or modifications can be arbitrarily applied to the components in other embodiments or modifications. Parts of the components in the above embodiments or modifications can be omitted as appropriate without departing from the spirit of one aspect of the present invention. In the above embodiment, the cart V holds the article M below the track R, but the main body 10 may be disposed above the track R and hold the article M above the track R. [Explanation of symbols]

[0103] 1...overhead traveling vehicle system, 2...overhead traveling vehicle, 8...carriage controller (control unit), 10...main body, 20...traveling vehicle, 30...traveling unit, 31...traveling wheel, 33...traveling drive motor, 36...support unit, 40...wheel turning mechanism (steering drive unit), 43...steering motor, 43b...output shaft, 46...first gear, 47...second gear, C...cell, D1...first traveling direction (first direction), D2...second traveling direction (second direction), L30...turning axis, L31...rotation axis, M1...cell recognition mark (first mark), M2...position recognition mark (second mark), R...track, R1...first rail, R2...second rail, S1...cell recognition sensor (first sensor), S2...position recognition sensor (second sensor).

Claims

1. At least a portion of the tracks are arranged in a grid pattern; an overhead traveling vehicle having a traveling unit that travels along the track, a steering drive unit that turns the traveling unit, and a main body that is disposed below the track and suspended from the traveling unit, the running unit includes a running wheel that rolls on the track around a rotation axis and is rotatable around a swivel axis, The steering drive unit is provided below the track and below the traveling wheels, and causes the traveling wheels to turn.

2. 2. The overhead traveling vehicle system according to claim 1, wherein the traveling unit further includes a traveling drive motor provided on the rotation shaft of the traveling wheel.

3. The track includes a plurality of first rails extending in a first direction and a second rail extending in a second direction perpendicular to the first direction, the first rail and the second rail are arranged in a grid pattern, the overhead traveling vehicle moves in the first direction by the traveling unit traveling on a pair of the first rails adjacent to each other in the second direction, and moves in the second direction by the traveling unit traveling on a pair of the second rails adjacent to each other in the first direction, The overhead traveling vehicle is a first sensor that acquires the first information from a first mark that indicates the first information; a second sensor that acquires second information from a second mark that indicates second information that is different from the first information, Each of the first rail and the second rail includes: a first surface facing the first sensor and on which the first mark is disposed; 3. The overhead traveling vehicle system according to claim 2, further comprising: a second surface facing the second sensor and on which the second mark is arranged, the second surface being arranged outside the first surface and inclined toward the overhead traveling vehicle relative to the first surface when viewed from the center of a cell, which is a space surrounded by the pair of first rails and the pair of second rails in a plan view.

4. The traveling unit further includes a support member that pivotally supports the traveling wheel, The steering drive unit is a steering motor as a drive source; a first gear connected to an output shaft of the steering motor; 2. The overhead traveling vehicle system according to claim 1, further comprising: a second gear that meshes with the first gear and is connected to the support member.

5. 5. The overhead traveling vehicle system according to claim 4, wherein the steering motor is provided so that an output shaft of the steering motor is parallel to the rotation shaft.

Images