Abstract:
A transport facility includes a track, and first and second transport vehicles that travel along the track. In order to supply electric power to the transport vehicles, a flexible first cable guide which includes a front-end attached to the first vehicle and a base-end fixed to the track, is folded back in a U-shape between the base-end and the front-end, is provided on a first side of the track, and supplies electric power to the first vehicle, and a flexible second cable guide which includes a front-end attached to the second vehicle and a base-end fixed to the track, is folded back in a U-shape between the base-end and the front-end, is provided on a second side of the track, and supplies electric power to the second vehicle. Thus, the first and second flexible cable guides are compactly installed while preventing interference therebetween.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention relates to a transport facility for use in an automated warehouse and the like, and particularly relates to supplying electric power to the transport vehicle. 
         [0003]    2. Description of the Related Art 
         [0004]    An automated warehouse in which two transport vehicles travel on the same track is known (JP 2007-1692). In such an automated warehouse, racks are divided into a common area to which the two transport vehicles access, and dedicated areas to which only one transport vehicle accesses. The transport vehicles are controlled so as to be prevented from interfering with each other in the common area. 
         [0005]    Meanwhile, when electric power is supplied to the transport vehicles via cable guides, interference between the cable guides becomes a problem. On the other hand, a cable guide is a member having a large width, and needs a large space in order to be installed. Therefore, it is necessary to make it possible to compactly install a pair of cable guides while preventing the interference between the cable guides. 
       SUMMARY OF THE INVENTION 
       [0006]    Preferred embodiments of the present invention make it possible to compactly install a pair of cable guides while preventing interference between the cable guides. 
         [0007]    A transport facility according to a preferred embodiment of the present invention includes a track; and a first transport vehicle and a second transport vehicle that are configured to travel commonly along the track. The transport facility further includes a flexible first cable guide which includes a front end section attached to the first transport vehicle and a base end section fixed to the track, is folded back in a U-shape between the base end section and the front end section, is arranged on a first side of the track, and supplies electric power to the first transport vehicle; and a flexible second cable guide which includes a front end section attached to the second transport vehicle and a base end section fixed to the track, is folded back in a U-shape between the base end section and the front end section, is arranged on a second side of the track, and supplies electric power to the second transport vehicle. 
         [0008]    In various preferred embodiments of the present invention, it is possible to reliably supply electric power to the first transport vehicle and the second transport vehicle via the cable guides without the cable guides interfering with each other. Furthermore, since the first transport vehicle and the second transport vehicle preferably may have the same configuration and the first cable guide and the second cable guide preferably may have the same configuration, manufacturing thereof is easy. 
         [0009]    It is preferable that the first cable guide and the second cable guide are arranged such that the front end sections are respectively folded back upward in a U-shape toward the base end sections, preferably a first support member which supports the first cable guide from below is provided in an area that is closer to the second transport vehicle and on the first side of the track when viewed from the center in a traveling direction of the track. Further, a second support member which supports the second cable guide from below is provided in an area that is closer to the first transport vehicle and on the second side of the track when viewed from the center in the traveling direction of the track. Accordingly, it is possible to prevent the cable guides folded back upward from rubbing against the floor surface of the track or the like which would cause dust and wearing. 
         [0010]    It is particularly preferable that each of the first support member and the second support member includes a plurality of brackets that are arranged at a distance and a plurality of rollers, and the rollers are supported by the brackets so as to be rotatable. Accordingly, it is possible to prevent the cable guides from rubbing against the support member and creating dust, and particularly when pairs of left and right rollers are provided to support both the left and right end sections of each cable guide, no force is applied to an electric power feeder accommodated in the central portion of the cable guide. 
         [0011]    It is preferable that the base end section of the first cable guide is fixed to a position in a central portion of the track and in the area closer to the first transport vehicle. 
         [0012]    And when the first transport vehicle is located in the area closer to the first transport vehicle, the first cable guide is folded back in a U-shape from a state of being in contact with a floor surface of the track, whereas when the first transport vehicle is located in the area closer to the second transport vehicle, the first cable guide is folded back in a U-shape from the vicinity of the base end section and is supported by the first support member in a state of being raised from the floor surface of the track, the base end section of the second cable guide is fixed to a position in the central portion of the track and in the area closer to the second transport vehicle. 
         [0013]    Further, when the second transport vehicle is located in the area closer to the second transport vehicle, the second cable guide is folded back in a U-shape from a state of being in contact with the floor surface of the track, whereas when the second transport vehicle is located in the area closer to the first transport vehicle, the second cable guide is folded back in a U-shape from the vicinity of the base end section and is supported by the second support member in the state of being raised from the floor surface of the track. 
         [0014]    Accordingly, the transport vehicles are able to travel a relatively long distance with relatively short cable guides. Furthermore, the cable guides that are raised from the floor surface are reliably prevented from rubbing against the floor surface. 
         [0015]    Furthermore, it is preferable that electric power feeders are accommodated in central portions of the first cable guide and the second cable guide with respect to a left-right direction, which is a direction that is perpendicular or substantially perpendicular to the traveling direction in a horizontal plane, and a pair of the rollers are provided on both the left and right sides of each bracket in the left-right direction. Accordingly, no stress is applied to the electric power feeders by the rollers. 
         [0016]    Furthermore, an automated warehouse according to a preferred embodiment of the present invention includes the above-described transport facility; pillars that are provided relatively close to the track; pillars that are provided on sides opposite to the track; and racks that include rack boards, wherein a pair of the racks are provided on the two sides of the track, the pillars of each rack that are close to the track are provided rearward with respect to a front end of the corresponding rack board that is close to the track, and at least portions of the first cable guide and the second cable guide are arranged in spaces below the respective rack boards, the spaces being created due to the pillars close to the track being provided rearward. Accordingly, it is possible to accommodate the cable guides using the spaces below the rack boards, resulting in space saving. 
         [0017]    The above and other elements, features, steps, characteristics and advantages of the present invention will become more apparent from the following detailed description of the preferred embodiments with reference to the attached drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0018]      FIG. 1  is a plan view showing an automated warehouse according to a preferred embodiment of the present invention. 
           [0019]      FIG. 2  is a side view showing a transport facility and a cable guide. 
           [0020]      FIG. 3  is a front view of main portions of the transport facility and racks. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0021]    The following describes preferred embodiments of the present invention. The scope of the present invention is based on the recitation of the claims, and is intended to be determined in accordance with the understanding of a person skilled in the art with reference to the recitation of this description and well-known techniques in the field of the present invention. 
         [0022]      FIGS. 1 to 3  show an automated warehouse  2  and transport vehicles  4  and  5  according to a preferred embodiment of the present invention. The transport vehicles  4  and  5  are, for example, stacker cranes, but may be another type of transport vehicles that do not include a mast  6 . The transport vehicles  4  and  5  preferably have the same or substantially the same configuration and each include a transfer device  7  that moves up and down along the mast  6 . However, without the transfer device  7  that directly moves up and down a transport vehicle with a lift platform (not shown) on which the transfer device  7  is mounted moves up and down along the mast  6  is usable. A flexible cable guide  8  is attached to the transport vehicle  4  and a flexible cable guide  9  is attached to the transport vehicle  5 , and electric power is supplied to the transport vehicles  4  and  5  via the cable guides  8  and  9  from base end sections  22  and  23  thereof on the ground. The reference numerals  28  and  29  denote front end sections of the cable guides  8  and  9  attached to the transport vehicles  4  and  5 , respectively. 
         [0023]    The transport vehicles  4  and  5  travel on a common traveling rail  10 , and C denotes the center of the rail, that is, the center of the traveling rail  10  in the traveling direction. The traveling space in which the transport vehicles  4  and  5  travel is a space that includes the traveling rail  10  and the spaces to the left and right thereof (in the direction that is orthogonal, in the horizontal plane, to the traveling direction of the transport vehicles  4  and  5 , that is, the up-down direction of  FIG. 1 ). Furthermore, a pair of, for example, left and right racks  12  and  13  are provided on the left and right of the traveling space. Instead of the pair of left and right racks, one rack may be provided only either on the right or the left. The racks  12  and  13  are divided into a common area  14  that is located in the center of the traveling rail  10  and to which both the transport vehicles  4  and  5  access, a dedicated area  15  that is located on one end side of the traveling rail  10  and to which only the transport vehicle  4  accesses, and a dedicated area  16  that is located on the other end side of the traveling rail  10  and to which only the transport vehicle  5  accesses. The reference numeral  18  denotes pillars for the racks  12  and  13  that are located on the rear ends thereof when viewed from the traveling rail  10 . Furthermore, as shown in  FIG. 3 , pillars  36  on the front sides are provided at rearward positions below rack boards  38 , which are the lowermost stages of rack boards having stages in the vertical direction, so as to enable portions of the spaces below the rack boards  38 , which are the lowermost stages, to be available for the cable guides  8  and  9 . Also, the pillars  18  and  36  support the racks  12  and  13 . 
         [0024]    The cable guide  8  is arranged laterally on one of the left and right sides of the traveling rail  10  and the cable guide  9  is arranged laterally on the other side of the traveling rail  10 , and the base end sections  22  and  23  of the cable guides  8  and  9  are arranged symmetrically with respect to the rail center C. Furthermore, the cable guide  8  is arranged so as to use the space below the lowermost rack board of the rack  12 , and the cable guide  9  is arranged so as to use the space below the lowermost rack board of the rack  13 . Moreover, a unit constituted by the transport vehicle  4  and the cable guide  8  and a unit constituted by the transport vehicle  5  and the cable guide  9  have the same configuration, and are arranged symmetrically with respect to the rail center C such that the masts  6  face each other. Accordingly, it is only needed to manufacture the uniform transport vehicles  4  and  5  and the uniform cable guides  8  and  9 , and to install them in the automated warehouse  2 , allowing a reduction in the manufacturing cost. Furthermore, if the masts  6  of the transport vehicles  4  and  5  are arranged close to the rail center C, not the masts  6  but the transfer devices  7  will be located at the ends of the traveling rail  10 , leading to an extension of the range of the racks to which the transport vehicles  4  and  5  can access. 
         [0025]    The positions of the transport vehicles  4  and  5  and the shapes of the cable guides  8  and  9  are illustrated with reference to  FIG. 2 , in which the transport vehicle  5  and the cable guide  9  are taken as an example. The transport vehicle  4  and the cable guide  8  have a symmetrical relationship to the components in  FIG. 2  with respect to the rail center C. The transport vehicle  5  can travel to the farthest back portion of the dedicated area  16  and the transport vehicle  4  can travel to the farthest back portion of the dedicated area  15 . The cable guides  8  and  9  respectively have preferably U-shaped sections  26 , which are folded in a U-shape, between the base end sections  22 ,  23  and the front end sections  28 ,  29 , and the positions of the U-shaped sections  26  are changed due to the travel of the transport vehicles  4  and  5 . When the transport vehicle  5  travels from the rail center C toward the dedicated area  16 , the cable guide  9  is folded back at its U-shaped section  26  from a state of being in contact with the floor surface of the track, and when the transport vehicle  5  travels from the rail center C toward the dedicated area  15 , the cable guide  9  is folded back in the U-shape from the vicinity of the base end section  23  and extends to the front end section  29  in the state of being raised from the floor surface of the track. Since the cable guides  8  and  9  will create dust and also be damaged if the cable guides  8  and  9  are suspended and allowed to rub against the floor surface of the automated warehouse  2 , support members  20  for use for the transport vehicle  4  and support members  21  for use for the transport vehicle  5  are provided on the lateral sides of the traveling rail  10  so as to support the lower portions of the cable guides  8  and  9 . The support member  20  for use for the transport vehicle  4  are arranged closer to the dedicated area  16  than the rail center C at an appropriate distance, and the support member  21  for use for the transport vehicle  5  are arranged closer to the dedicated area  15  than the rail center C at an appropriate distance. 
         [0026]    Stocks in the racks  12  and  13  and the movement of the transport vehicles  4  and  5  are controlled by a controller  24  on the ground side, and the transport vehicles  4  and  5  perform communication with the controller  24  on the ground side via the cable guides  8  and  9 , or perform wireless communication such as optical communication with the controller  24  on the ground side. Also, the controller  24  gives an instruction to perform a transportation operation such that interference of the transport vehicles  4  and  5  is prevented. 
         [0027]      FIG. 3  shows arrangement of the cable guide  8  and the racks  12  and  13  with reference to the transport vehicle  4 , for example; the counterparts preferably are similarly arranged. The reference numeral  30  denotes a drive wheel, the reference numeral  31  denotes a traveling motor, and the reference numeral  32  denotes a lifting motor configured to move the transfer device up and down. Each support member  20  supports a pair of, for example, left and right rollers on two sides  33  of a C-shaped bracket so that the rollers are rotatable, that is, the rollers  34  support the vicinity of the left and right sides of the cable guide  8  from below. Accordingly, the underside of the cable guide  8  does not rub against the floor surface. Note that the support members  21  preferably have the same configuration as that of the support members  20 , and are arranged point-symmetrically to the support members  20  with respect to the rail center C. The pairs of rollers  34  support the cable guides  8  and  9  such that no force is applied to electric power feeders accommodated in the central portions of the cable guides. 
         [0028]    Packages  39  such as cassettes in which substrates of flat panel displays are accommodated or cassettes in which semiconductor wafers are accommodated are arranged on the rack boards  38 , and the rear end pillars  18  are arranged as shown in  FIG. 1  and the front side pillars  36  are arranged at positions located rearward with respect to the front ends of the rack boards  38 . Therefore, the spaces between the pillars  36  and the traveling rail  10  are available for the cable guides  8  and  9 . In  FIG. 3 , the cable guide  8  is partially accommodated in the space below the rack board  38 , but the cable guide  8  may entirely be accommodated therein. 
         [0029]    In the present preferred embodiment, one traveling rail  10  preferably is used, but a configuration is also possible in which two traveling rails are provided and the cable guides  8  and  9  are arranged outside the two traveling rails with respect to the left-right direction. Furthermore, in the present preferred embodiment, “transport facility” refers to a facility that preferably includes by the transport vehicles  4  and  5 , the cable guides  8  and  9 , the support members  20  and  21  including the rollers  34 , and spaces in which these constituent components are installed. 
         [0030]    According to the present preferred embodiment, the following advantages are achieved: 
         [0031]    1) Interference between the cable guides  8  and  9  is prevented, and electric power is reliably supplied to the transport vehicles  4  and  5  in contrast to the case where electric power is supplied via the rail. 
         [0032]    2) Space saving is achieved since the spaces below the racks  12  and  13  are available for the cable guides  8  and  9 . 
         [0033]    3) The manufacturing cost is reduced since the transport vehicles  4  and  5  preferably have the same configuration and the cable guides  8  and  9  preferably have also the same configuration. 
         [0034]    4) The support members  20  and  21  prevent the cable guides  8  and  9  from rubbing against the floor surface, and the rollers  34  smoothly move the cable guides  8  and  9 . Therefore, the present preferred embodiment is particularly suitable for an automated warehouse in a clean room, for example. 
         [0035]    While preferred embodiments of the present invention have been described above, it is to be understood that variations and modifications will be apparent to those skilled in the art without departing from the scope and spirit of the present invention. The scope of the present invention, therefore, is to be determined solely by the following claims.