Ceiling transport vehicle

Abstract

This overhead conveyance vehicle comprises: a traveling cart that travels on a track; a body section provided so as to be rotatable relative to the traveling cart; a transfer device that is provided to the body section and capable of dispatching articles horizontally; and an obstacle sensor that is provided in the body section so as not to overlap with the direction in which the transfer device dispatches articles, said obstacle sensor serving to detect obstacles located in front of the traveling cart in the direction of travel thereof.

Description

[Technical Field]

[0001] One aspect of the present disclosure relates to an overhead transport vehicle. [Background technology]

[0002] An overhead transport vehicle is known that includes a traveling carriage that travels along a track and a main body that is connected to the traveling carriage and positioned below the track. Such an overhead transport vehicle is equipped with an obstacle sensor that detects obstacles that may obstruct the vehicle while traveling. For example, the overhead transport vehicle described in Patent Document 1 is equipped with a transfer device that is connected to the underside of the traveling carriage and is rotatable relative to the traveling carriage. The obstacle sensor is attached to the lower end of a support member that extends downward from the traveling carriage, and this support member is positioned at a portion of the periphery of the transfer device. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 7040637 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the above-mentioned conventional ceiling transport vehicle, a support member is provided around a portion of the transfer device, so even if the transfer device is rotatable relative to the traveling cart, it is not possible to send out (move horizontally) items in the direction in which the support member is located, and there are limitations on the transfer positions to which items can be transferred.

[0005] Therefore, an object of one aspect of the present disclosure is to provide an overhead transport vehicle that can increase the degree of freedom in the position to which an article is transferred by a transfer device. [Means for solving the problem]

[0006] A ceiling transport vehicle according to one aspect of the present disclosure comprises a traveling carriage that travels on a track, a main body that is rotatable relative to the traveling carriage, a transfer device that is provided on the main body and is capable of sending out items horizontally, and an obstacle sensor that is provided on the main body so as not to overlap with the direction in which the transfer device sends out items and that detects obstacles located ahead of the traveling carriage in the direction of travel.

[0007] In an overhead transport vehicle with this configuration, when the main body rotates relative to the traveling carriage, the obstacle sensor and the transfer device rotate together, so the position of the obstacle sensor does not overlap with the direction in which the transfer device sends out articles. This eliminates the need for a support member for attaching the obstacle sensor to the traveling carriage in the direction in which articles are sent out from the transfer device. As a result, the transfer device can send out articles in any direction, increasing the degree of freedom in the position in which articles are transferred by the transfer device.

[0008] In an overhead transport vehicle according to one aspect of the present disclosure, the traveling carriage may be arranged in a grid pattern on a track including a plurality of first rails extending in a first direction and a plurality of second rails extending in a second direction perpendicular to the first direction, and the traveling carriage may move in the first direction by traveling on a pair of first rails adjacent to each other in the second direction, and move in the second direction by traveling on a pair of second rails adjacent to each other in the first direction. This configuration increases the degree of freedom in the traveling direction of the traveling carriage, while also increasing the degree of freedom in the transfer position of the article by the transfer device.

[0009] The overhead transport vehicle according to one aspect of the present disclosure may further include a control unit that, when the traveling carriage starts traveling, rotates the main body so that the detection area of ​​the obstacle sensor faces forward in the traveling direction of the traveling carriage. With this configuration, regardless of where the obstacle sensor is installed on the main body, when the overhead transport vehicle is traveling, it is possible to detect an obstacle located forward in the traveling direction.

[0010] An obstacle sensor for an overhead transport vehicle according to one aspect of the present disclosure includes a first sensor arranged to be able to detect an obstacle on one side of the main body in a predetermined direction, and a second sensor arranged to be able to detect an obstacle on the other side of the predetermined direction, and the control unit may rotate the main body so that the detection area of ​​one of the first sensor and the second sensor faces forward in the traveling direction of the traveling vehicle, depending on the traveling direction when the traveling vehicle starts traveling, and may disable the detection of obstacles by the other of the first sensor and the second sensor. In this configuration in which two obstacle sensors are provided in the main body, the time required to rotate the main body so that the detection area of ​​the obstacle sensor faces forward in the traveling direction of the traveling vehicle can be shortened compared to when only one obstacle sensor is provided in the main body.

[0011] In the overhead transport vehicle according to one aspect of the present disclosure, the control unit may determine which of the detection areas of the first sensor and the second sensor should face forward in the traveling direction of the traveling vehicle, based on information on which direction perpendicular to the traveling direction the article will be transferred to at the next transfer location. This configuration can shorten the time required for turning for transfer after arriving at the next transfer location. [Effects of the Invention]

[0012] According to one aspect of the present disclosure, it is possible to increase the degree of freedom in the position to which an article is transferred by a transfer device. [Brief explanation of the drawings]

[0013] [Figure 1] FIG. 1 is a perspective view illustrating an example of a guided 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 of the overhead transport vehicle in FIG. 1 as viewed from the X direction. [Figure 4] 4 is a perspective view of the ceiling transport vehicle in FIG. 1 as seen obliquely from above. [Figure 5]FIG. 5 is a perspective view showing only the rail 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] 7 is a perspective view of the ceiling transport vehicle in FIG. 1 as seen obliquely from below. [Figure 8] 8 is a side view of the ceiling transport vehicle in FIG. 1 as seen from the Y direction. [Figure 9] FIG. 9 is a block diagram showing the functional configuration of the ceiling transport vehicle system according to the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0014] Hereinafter, embodiments of the present disclosure 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 will be referred to as the X direction (first direction), a direction perpendicular to the X direction and along the horizontal plane will be referred to as the Y direction (second direction), and the vertical direction will be referred to as the Z direction.

[0015] As shown in FIG. 1, an overhead transport vehicle system 1 according to an embodiment is a grid system (transport system or rail-guided vehicle system) for transporting articles M by overhead transport vehicles 2, for example, in a clean room of a semiconductor manufacturing factory. The overhead transport vehicle system 1 includes, for example, a plurality of overhead transport vehicles 2 (hereinafter collectively referred to as "transport vehicles 2"), a system controller 5 that controls the plurality of transport vehicles 2, and a track R along which the plurality of transport vehicles 2 travel. The transport vehicles 2 move along the track R of the overhead transport vehicle system 1. The transport vehicles 2 travel along the track R and transport articles M, such as FOUPs (Front Opening Unified Pods) that house semiconductor wafers or reticle pods that house reticles. The transport vehicles 2 may also be referred to as carts, transport vehicles, transport carriers, or traveling carriers. The plurality of transport vehicles 2 enables high-density transport of the articles M, improving the efficiency of transporting the articles M. Note that the overhead transport vehicle system 1 may also include only one transport 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 transport vehicle 2. The stocker stores the article M transported by the transport 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 ceiling transport 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 each other. 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 each other 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 after molding each of the first rail member 110, second rail member 120, and intersection rail member 130. Each first rail member 110 includes a first beam portion 111 disposed at the upper end position of the rail unit 100 and extending in the X direction, a first rail (traveling rail) R1 disposed at the lower end position 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 (traveling 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 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 multiple squares by the multiple first rails R1 and the multiple second rails R2. The intersection rail R3 is located at a portion 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 with a gap in the X direction. The intersection rail R3 is adjacent to the second rail R2 with a gap in the Y direction. The intersection rail R3 is used when the guided vehicle 2 travels along the first rail R1, when the guided vehicle 2 travels along the second rail R2, and when the guided 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 (relative to the first rails R1) between two first rails R1 adjacent in the Y direction and two other first rails R1 adjacent in the Y direction. In addition, the same four intersection rails R3 as above are arranged at intervals (relative to the second rails R2) 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 transport 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 transport 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 transport vehicle 2 passes in a straight line between the rail units 100, the traveling wheels 31 of the transport vehicle 2 travel on the intersecting traveling surface R3a. At that time, the traveling wheels 31 pass over any two of the four intersecting rails R3 described above. Alternatively, when the transport 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 transport vehicle 2 pass over the intersecting traveling surface 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 ceiling transport 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 transport vehicle system 1 includes a communication system (not shown). The communication system is used for communication between the transport vehicles 2 and the system controller 5. The transport 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 transport vehicle 2 will be described with reference to FIGS. 1, 3, and 4. As shown in FIGS. 1 and 3, the transport vehicle 2 is provided so as to be able to travel along a track R. The transport vehicle 2 has a traveling carriage 20 that travels on the track R, and a main body 10 that is attached to the lower part of the traveling carriage 20 and is rotatable relative to the traveling carriage 20. The traveling carriage 20 includes a carriage 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 carriage unit 50 in a plan view and that protrude upward from the carriage unit 50, and four wheel turning mechanisms 40 that turn each of the four traveling wheels 31 of the running section 30 relative to the carriage unit 50. A carriage controller (control unit) 8 is provided inside the carriage unit 50.

[0030] The main body 10 is disposed below the track R. 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 have dimensions that fit into one square on the track R (see FIG. 1) in a plan view. The transport vehicle 2 can pass other transport vehicles 2 traveling on the 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 of its circumference. 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 transport 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 top plate 12a. A first 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 first rotation drive unit 16 is provided below the slide mechanism 11, and the lift drive unit 14 is provided below the first 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 transport vehicle 2, and is the point where the article M is handed over to and from the transport 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 arranged in a stacked manner in the Z direction, for example. By rotating the main body 10, the slide mechanism 11 moves the first 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 movement direction 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 movement direction of the movable plates coincides with the position of the opening of the cylindrical frame 12b.

[0036] The first 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 first 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 first rotation drive unit 16 can orient the laterally protruding article holder 13 (or the article M held by the article holder 13) in a desired direction. The slide mechanism 11 and the first rotation drive unit 16 are controlled by the cart controller 8. Note that the lift drive unit 14 can be rotated by the first rotation drive unit 16 even when the movable plate of the slide mechanism 11 is stored without moving (the state indicated 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 second rotation drive unit 52A, such as an electric motor, is provided on the top plate 12a. When the driving force of the second rotation drive unit 52A 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 transport vehicle 2 can use the transfer device 18 to deliver the article M to and from the load port.

[0038] A cover 17 is attached to the outer surface of the cylindrical frame 12b. The cover 17 surrounds the transfer device 18 and the article M held by the transfer device 18. The cover 17 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] As shown in FIGS. 7 and 8 , the cylindrical frame 12b is provided with an obstacle sensor 61 that detects an obstacle located ahead in the traveling direction of the transfer vehicle 2 (traveling carriage 20). More specifically, the obstacle sensor 61 is provided at the lower part of the cylindrical frame 12b so as to protrude downward from the lower end of the cylindrical frame 12b (cover 17). The obstacle sensor 61 is, for example, an optical sensor that detects an obstacle by emitting detection light. The emission area of ​​the detection light may be linear, strip-shaped, or radial. The obstacle sensor 61 may also be a sensor that can detect the distance from the obstacle sensor 61. The detection result of the obstacle sensor 61 is acquired by the carriage controller 8. The obstacle sensor 61 may be provided at the lower part of the cylindrical frame 12b by cutting out a portion of the lower part of the cover 17, rather than protruding downward from the lower end of the cylindrical frame 12b.

[0040] The obstacle sensor 61 of this embodiment includes a first sensor 61a arranged to be able to detect an obstacle on one side of the main body 10 in the predetermined direction D, and a second sensor 61b arranged to be able to detect an obstacle on the other side of the predetermined direction D. For example, when the main body 10 is rotated relative to the traveling carriage 20 so that the predetermined direction D of the main body 10 coincides with the X direction, the first sensor 61a detects an obstacle on one side of the X direction, and the second sensor 61b detects an obstacle on the other side of the X direction. Note that, as will be described in detail later, when the transport vehicle 2 is traveling, the detection function of one of the first sensor 61a and the second sensor 61b is disabled. Note that the predetermined direction D of the main body 10 indicates the orientation of the main body 10. The orientation of the main body 10 can be based on, for example, a direction along the arrangement direction of the pair of claws 13a, a direction along the arrangement direction of the pair of anti-sway members 71, a direction perpendicular to the protruding direction of the movable plate of the slide mechanism 11, or the like.

[0041] The detection direction (the direction of emission of detection light) of the obstacle sensor 61 is directed slightly downward rather than horizontally, as shown in Fig. 8. This allows the obstacle sensor 61 to detect an obstacle that is about to enter the travel area of ​​the transport vehicle 2 from below in the vertical direction or an obstacle that has entered the travel area of ​​the transport vehicle 2 from below, without detecting other transport vehicles 2. Note that the term "obstacle" as used here includes any member, part of a worker, etc.

[0042] The following description will be given taking as an example a case where the article M is a container (FOUP, etc.) with a lid on its front surface. In this case, the article M has a flange portion Ma, as well as a front surface Mb on which the lid or the like is provided, side surfaces Mc that are the sides other than the front surface Mb, a bottom surface Md that is the bottom, and a top surface Me on which the flange portion Ma is provided. The bottom surface Md is provided with positioning holes that fit into positioning pins provided on the load port when the article is placed on the load port. The orientation of such an article M is set based on the direction in which the lid is arranged, the arrangement direction of the positioning holes (arrangement pattern), etc., as described above.

[0043] The main body 10 has an article holding mechanism 70 including a pair of anti-sway members 71, 71, a pair of article fall prevention members 72, 72, and a pair of lid fall prevention members 73, 73.

[0044] The pair of anti-swaying members 71, 71 are provided to come into contact with the article M and prevent the article M from swaying during travel. One of the pair of anti-swaying members 71, 71 is provided at the first end 12c in the predetermined direction D of the main body 10, and the other of the pair of anti-swaying members 71, 71 is provided at the second end 12d. Each of the pair of anti-swaying members 71, 71 is provided so as to be able to advance to a predetermined position or retract from a predetermined position, and comes into contact with the article M in the advanced position and moves away from the article M in the retracted position.

[0045] Each of the pair of anti-sway members 71, 71 is composed of two roller members arranged in a direction perpendicular to the predetermined direction D (the Y direction in this embodiment). This reduces friction between the pair of anti-sway members 71, 71 and the article M when the pair of anti-sway members 71, 71 advance to the advanced position and come into contact with the article M. As described above, for example, when the main body 10 is rotated relative to the traveling carriage 20 so that the predetermined direction D in the main body 10 coincides with the X direction, the pair of anti-sway members 71, 71 come into contact with the article M so as to sandwich it from both ends in the X direction.

[0046] The pair of article fall prevention members 72, 72 are provided to prevent the article M from falling downward from the transfer device 18 during travel. One of the pair of article fall prevention members 72, 72 is provided at the first end 12c in the predetermined direction D of the main body 10, and the other of the pair of article fall prevention members 72, 72 is provided at the second end 12d. Each of the pair of article fall prevention members 72, 72 is provided so as to be able to advance to a predetermined position or retract from a predetermined position, and is located below the article M in the advanced position and is away from below the article M in the retracted position.

[0047] The pair of lid drop prevention members 73, 73 are provided to prevent the lid provided on the front surface Mb from falling below the transport vehicle 2 when it comes off. One of the pair of lid drop prevention members 73, 73 is provided at the first end 12c in the predetermined direction D of the main body 10, and the other of the pair of lid drop prevention members 73, 73 is provided at the second end 12d. Each of the pair of lid drop prevention members 73, 73 is provided so as to be able to advance to or retract from a predetermined position, and is located in front of the lid of the article M in the advanced position, and is away from the front of the lid of the article M in the retracted position.

[0048] The pair of anti-sway members 71, 71, the pair of article fall prevention members 72, 72, and the pair of lid fall prevention members 73, 73 are driven to advance to the advanced position and retreat to the retreated position by a drive unit such as a single electric motor (not shown). That is, the pair of anti-sway members 71, 71, the pair of article fall prevention members 72, 72, and the pair of lid fall prevention members 73, 73 advance to the advanced position and retreat to the retreated position at approximately the same time. The pair of anti-sway members 71, 71, the pair of article fall prevention members 72, 72, and the pair of lid fall prevention members 73, 73 are connected to the drive unit by link members or the like.

[0049] The travel unit 30 has four travel wheels 31. Two auxiliary wheels 32 are provided for each travel wheel 31. As shown in FIG. 4, the travel wheels 31 are provided at the four corners of the carriage unit 50 so as to protrude upward from the top cover 51. Each travel wheel 31 is rotatable around a horizontal or nearly horizontal axle axis along the XY plane. A travel drive motor 33 is provided on the rotation axis of each travel wheel 31. Each travel wheel 31 is driven to rotate by the driving force of the travel drive motor 33. The travel drive motor 33 is configured to be able to switch between forward and reverse rotation, for example. Each travel wheel 31 rolls on the track R. Each travel 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 travel the transport vehicle 2. It should be noted that the present invention is not limited to a configuration in which all of the four traveling wheels 31 are rotationally driven by the driving force of the traveling drive motor 33, and a configuration in which only some of the four traveling wheels 31 are rotationally driven may also be adopted.

[0050] Four wheel swivel mechanisms 40 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 swivel 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 portion 35 and a support member 36. 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 portion 35, running wheels 31, auxiliary wheels 32, and running drive motor 33 are disposed above the top cover 51.

[0051] 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 positioned 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 member 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 member 36 maintains the relative positions of the running wheels 31 and the auxiliary wheels 32.

[0052] As shown in FIG. 4, the traveling wheels 31 are provided so as to be rotatable about rotation axes L30 extending in the vertical direction. The four rotation axes L30 are arranged at the vertices of a square in a plan view, and the rotation axis L10 is arranged 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 (displaced). The traveling wheels 31 are rotated by the wheel rotation mechanism 40, and as a result, the traveling direction of the transport vehicle 2 can be changed.

[0053] The auxiliary wheels 32 are arranged one at the front and one at the rear of 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 wheel 31 is 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 wheel 31 passes 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 auxiliary wheels 32 come into contact with auxiliary members (described in detail below) provided on the first rail R1 and the second rail R2, thereby preventing the running wheel 31 from dropping. Note that the number of auxiliary wheels 32 provided per running wheel 31 is not limited to two. For example, one running wheel 31 may be provided with one auxiliary wheel 32.

[0054] 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 traveling 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 member 36, the traveling wheels 31, the auxiliary wheels 32, and the traveling drive motor 33 together around the swivel axis L30. With the transport vehicle 2 positioned at the center of each rail unit 100, each traveling wheel 31 is rotated 90 degrees around the swivel axis L30. This causes the traveling wheels 31 to rotate on the intersection rail R3. This allows the transport vehicle 2 to turn. Turning refers to switching from a first state in which the transport vehicle 2 travels in a first travel direction D1 to a second state in which the transport vehicle 2 travels in a second travel direction D2, or from the second state in which the transport vehicle 2 travels in the second travel direction D2 to the first state in which the transport vehicle 2 travels in the first travel direction D1. The transport vehicle 2 turns, for example, when the transport vehicle 2 is stopped. The transport vehicle 2 may also turn when the transport vehicle 2 is stopped but the article M is moving (for example, turning). The drive of the wheel turning mechanism 40 is controlled by the carriage controller 8.

[0055] As described above, a gap G is formed in the track R. When the transport vehicle 2 travels on the first rail R1 and crosses the second rail R2, or when the transport vehicle 2 travels on the second rail R2 and crosses the first rail R1, a part of the transport vehicle 2 (more specifically, for example, the connecting portion 35) passes through the gap G.

[0056] Note that a guide roller that abuts against the side of the intersecting 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 (transport vehicle 2) from shifting position relative to the track R.

[0057] The transport 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 transport 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.

[0058] The carriage controller 8 shown in FIGS. 3 and 9 performs overall control of the transport vehicle 2. The carriage controller 8 is a computer including a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and the like. The carriage 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 carriage controller 8 may also be configured as hardware including electronic circuits, for example. The carriage 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 configure a single carriage controller 8. The carriage controller 8 is provided in the carriage unit 50, for example.

[0059] The carriage controller 8 controls the travel of the transport vehicle 2 based on the transport command. The carriage controller 8 controls the travel of the transport vehicle 2 by controlling the travel drive motor 33, the steering motor 43, etc. The carriage controller 8 controls, for example, the travel speed, operations related to stopping, and operations related to changing direction. The carriage controller 8 controls the transfer operation of the transport 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 transport 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.

[0060] The bogie controller 8 controls the travel drive motor 33 (travel unit 30) based on the detection result of the first sensor 61a or the second sensor 61b. For example, when an obstacle is detected by the first sensor 61a or the second sensor 61b, the bogie controller 8 controls the travel drive motor 33 to stop the travel of the traveling bogie 20. If the first sensor 61a and the second sensor 61b are sensors that can detect the distance to an obstacle, the bogie controller 8 may control the travel drive motor 33 to make the traveling bogie 20 slow down when an obstacle is detected within a first distance, and may control the travel drive motor 33 to stop the traveling bogie 20 when an obstacle is detected within a second distance that is shorter than the first distance.

[0061] When the traveling carriage 20 starts traveling, the carriage controller 8 drives the second rotation drive unit 52A to rotate the main body unit 10 so that the orientation of the article M held by the transfer device 18 is constant with respect to the traveling direction of the traveling carriage 20. As described above, the article M has an orientation, and the carriage controller 8 rotates the main body unit 10 so that the front surface Mb on which the lid is provided faces in a direction perpendicular to the traveling direction. Here, the direction perpendicular to the traveling direction may be either the left or the right when the traveling carriage 20 is viewed from the front in the traveling direction.

[0062] 7 and 8, when the traveling carriage 20 starts traveling, the carriage controller 8 of this embodiment rotates the main body 10 so that the predetermined direction D in the main body 10 coincides with the traveling direction (the traveling direction at the start of traveling), thereby causing the front surface Mb on which the lid is provided to face a direction perpendicular to the traveling direction. More specifically, the carriage controller 8 rotates the main body 10 so that the direction in which the first end 12c and the second end 12d of the main body 10 are aligned roughly coincides with the traveling direction, in other words, so that the direction in which the pair of anti-sway members 71, 71 are arranged roughly coincides with the traveling direction, in other words, so that the detection direction of the first sensor 61a and the second sensor 61b roughly coincides with the traveling direction.

[0063] Here, "when the traveling carriage 20 starts traveling" may refer to all situations in which the transport vehicle 2 starts traveling from a stopped state, such as when the transport vehicle 2 starts traveling after switching its traveling direction at the intersection rail R3, when the transport vehicle 2 starts traveling after completing the transfer operation of the item M, when the transport vehicle 2 starts traveling after making an emergency stop, or it may refer only to, for example, when the transport vehicle 2 starts traveling after switching its traveling direction at the intersection rail R3.

[0064] The vehicle controller 8 rotates the main body 10 so that the detection area (emission direction of detection light) of one of the first sensor 61a and the second sensor 61b faces forward in the traveling direction of the traveling vehicle 20, depending on the traveling direction when the traveling vehicle 20 starts traveling, and disables the other of the first sensor 61a and the second sensor 61b from detecting an obstacle. In other words, the vehicle controller 8 rotates the main body 10 so that one of the first sensor 61a and the second sensor 61b can detect an obstacle ahead in the traveling direction of the traveling vehicle 20, and enables only one of the first sensor 61a and the second sensor 61b, which will detect an obstacle ahead in the traveling direction, to detect an obstacle, and disables the other of the first sensor 61a and the second sensor 61b, which will detect an obstacle behind in the traveling direction.

[0065] The carriage controller 8 determines whether to face the detection area of ​​one of the first sensor 61a and the second sensor 61b forward in the traveling direction of the traveling carriage 20 based on information on which direction perpendicular to the traveling direction the article M will be transferred to at the next transfer location. For example, assume that the load port that will be the next transfer location is located on the right side in the traveling direction of the transport vehicle 2. In this case, when the traveling carriage 20 starts traveling, the main body 10 is rotated so that the lateral direction of the slide mechanism 11 in the transfer device 18 (the open portion of the main body frame 12) faces right in the traveling direction. This makes it possible to omit the operation of rotating the main body 10 in the direction in which the load port is located when the transport vehicle 2 arrives at the next transfer location.

[0066] The system controller 5 shown in FIGS. 3 and 9 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 performed by the bogie controller 8.

[0067] The system controller 5 selects one of a plurality of transport vehicles 2 capable of transporting the item M, and assigns a transport command to the selected transport vehicle 2. The transport command includes a travel command to cause the transport 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.

[0068] The effects of the transport vehicle 2 of the above embodiment will be described. In the transport vehicle 2 of the above embodiment, when the main body 10 turns relative to the traveling carriage 20, the obstacle sensor 61 and the transfer device 18 turn together, and the position of the obstacle sensor 61 does not overlap with the direction in which the transfer device 18 sends out the article M. This eliminates the need for a support member for attaching the obstacle sensor 61 to the traveling carriage 20 in the direction in which the article M is sent out from the transfer device 18. As a result, the transfer device 18 can send out the article M in any direction, increasing the degree of freedom in the transfer position of the article M by the transfer device 18.

[0069] The traveling carriage 20 of the transport vehicle 2 in the above embodiment moves in the first direction by traveling on a pair of first rails R1, R1 adjacent to each other in the second direction, and moves in the second direction by traveling on a pair of second rails R2, R2 adjacent to each other in the first direction. This configuration increases the degree of freedom of the traveling direction of the traveling carriage 20, and also increases the degree of freedom of the transfer position of the article M by the transfer device 18.

[0070] The carriage controller 8 of the transport vehicle 2 in the above embodiment rotates the main body 10 so that the detection area of ​​one of the first sensor 61a and the second sensor 61b faces forward in the traveling direction of the traveling carriage 20, depending on the traveling direction when the traveling carriage 20 starts traveling, and disables the other of the first sensor 61a and the second sensor 61b from detecting an obstacle. In this manner, in the configuration of the above embodiment in which two obstacle sensors 6 (the first sensor 61a and the second sensor 61b) are provided on the main body 10, the time required to rotate the main body 10 so that the detection area of ​​the obstacle sensor 6 faces forward in the traveling direction of the traveling carriage 20 can be shortened compared to when only one obstacle sensor 6 is provided on the main body 10. Consequently, the transport capacity of the transport vehicle 2 can be improved.

[0071] The carriage controller 8 of the transport vehicle 2 in the above embodiment determines which detection area of ​​the first sensor 61a or the second sensor 61b should face forward in the traveling direction of the traveling carriage 20, based on information on which direction perpendicular to the traveling direction the article M will be transferred to at the next transfer location. This reduces the time required for turning for transfer after arriving at the next transfer location, and ultimately improves the transport capacity of the transport vehicle 2.

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

[0073] In the above embodiment, the guided vehicle 2 has been described with reference to an example in which two obstacle sensors, a first sensor 61a and a second sensor 61b, are provided as the obstacle sensor 61. However, the present invention is not limited to this. For example, the main body 10 may be provided with only one obstacle sensor 61. In this case, when the traveling vehicle 20 starts traveling, the vehicle controller 8 rotates the main body 10 so that the detection area of ​​the obstacle sensor 61 faces forward in the traveling direction of the traveling vehicle 20. As a result, regardless of where the obstacle sensor 61 is provided on the main body 10, when the guided vehicle 2 travels, it is possible to detect an obstacle located ahead in the traveling direction.

[0074] In the transport vehicle 2 of the above embodiment, an example has been described in which, when the traveling carriage 20 starts traveling, one of the first sensor 61a and the second sensor 61b that detects the area behind the traveling carriage 20 in the traveling direction is disabled from detecting an obstacle, but the obstacle may remain detectable. In this case, the carriage controller 8 may control the traveling carriage 20 (travel drive motor 33) based on detection information from only one of the first sensor 61a and the second sensor 61b that is arranged ahead of the traveling carriage 20 in the traveling direction.

[0075] The transport vehicle 2 of the above embodiment and the above modified example has been described as having an article holding mechanism 70 including a pair of anti-sway members 71, 71, a pair of article fall prevention members 72, 72, and a pair of lid fall prevention members 73, 73, but at least one of the pair of anti-sway members 71, 71, the pair of article fall prevention members 72, 72, and the pair of lid fall prevention members 73, 73 may be provided, or not all of them may be provided. Even in this case, the orientation of the article M may or may not be constant with respect to the traveling direction of the traveling carriage 20, for example, by orienting the front surface Mb of the article M in a direction perpendicular to the traveling direction of the transport vehicle 2.

[0076] In the above embodiment, an overhead transport vehicle 2 has been described as an example of a transport vehicle, but an AGV (Automated Guided Vehicle) that travels along a preset lattice-like route may also be used, or various known systems that travel along lattice-like travel paths may also be used. Also, in the above embodiment, an example of a transport vehicle 2 that holds an article M below the track R has been described, but the transport vehicle 2 may also have a main body 10 disposed above the track R and hold an article M above the track R.

[0077] Furthermore, in the above embodiment and the above modified example, an example of a rail on which the transport vehicle 2 runs is described as a track in which the first rail R1 and the second rail R2 are arranged in a grid pattern, but the track may also be a track that extends in one direction and includes branching and merging sections. [Explanation of symbols]

[0078] 1...ceiling transport vehicle system, 2...ceiling transport vehicle (transport vehicle), 5...system controller, 8...cart controller (control unit), 10...main body, 18...transfer device, 20...traveling cart, 30...traveling unit, 50...cart unit, 61...obstacle sensor, 61a...first sensor, 61b...second sensor, 70...article holding mechanism, 71...swing prevention member, 72...article fall prevention member, 73...lid fall prevention member, M...article, R...track, R1...first rail, R2...second rail, R3...intersection rail.

Claims

1. a traveling vehicle that travels on a track; a main body portion provided rotatably relative to the traveling carriage; a transfer device provided on the main body and capable of sending out an article in a horizontal direction; an obstacle sensor that is provided in the main body so as not to overlap with a direction in which the transfer device sends out the article and that detects an obstacle located ahead in a traveling direction of the traveling carriage; a control unit that rotates the main body unit so that the detection area of ​​the obstacle sensor faces forward in the traveling direction of the traveling vehicle when the traveling vehicle starts traveling, The track has a plurality of first rails extending in a first direction and a plurality of second rails extending in a second direction perpendicular to the first direction, and the traveling carriage moves in the first direction by traveling on a pair of the first rails adjacent to each other in the second direction, and moves in the second direction by traveling on a pair of the second rails adjacent to each other in the first direction, the obstacle sensor includes a first sensor arranged to be able to detect the obstacle on one side of the main body in a predetermined direction, and a second sensor arranged to be able to detect the obstacle on the other side of the main body in the predetermined direction, The control unit rotates the main body so that the detection area of ​​one of the first sensor and the second sensor faces forward in the direction of travel of the traveling cart, depending on the direction of travel when the traveling cart starts traveling, and disables the detection of the obstacle by the other of the first sensor and the second sensor.

2. The ceiling transport vehicle according to claim 1, wherein the control unit determines which detection area of ​​the first sensor and the second sensor should face forward in the direction of travel of the traveling cart based on information as to which direction perpendicular to the traveling direction the item will be transferred to at the next transfer location.

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