US20080022881A1

US20080022881A1 - Traveling rails for carriage

Info

Publication number: US20080022881A1
Application number: US11/826,984
Authority: US
Inventors: Toshio Takasu; Keitaro Kojima
Original assignee: Asyst Shinko Inc
Current assignee: Asyst Shinko Inc
Priority date: 2006-07-07
Filing date: 2007-07-19
Publication date: 2008-01-31
Also published as: TW200904738A; JP4848862B2; CN101100266A; JP2008013330A

Abstract

In a carriage traveling rail to which a carriage is movably attached, upper ends of a plurality of suspenders are fixed to a ceiling and the suspenders extend downward. A first linear rail member is elongated in one direction and suspended by the suspenders which are arranged with a prescribed interval. A curved rail module is curved in a vertical plane and elongated in the curved direction. The curved rail module is suspended by the suspenders which are arranged with a prescribed interval and includes a curved member having a curved face which is curved in the vertical plane along the elongated direction, and a plurality of second linear rail members elongated in one direction and fixed to the curved member. The second rail members are shorter than the first linear rail member in length relative to the elongated direction. The second linear rail members are in contact with the curved face while being so arranged that adjacent ones of the second linear members are elongated in directions different from each other and end faces in the elongated direction of the adjacent ones of the second linear members oppose each other, so that the carriage travels while being guided by the second linear rail members.

Description

BACKGROUND

The present invention relates to traveling rails on which a carriage is movably mounted.
Japanese Patent Publication No. 2005-112563A discloses a transport system in which an OHT (Overhead Hoist Transport) carriage is suspended on a rail (carriage traveling rail) suspended on a ceiling and the OHT carriage is movable along the rail (the carriage is movably attached to the carriage traveling rail).
Here, when the transport system is used in a clean room for producing a semiconductor or a liquid crystal device, new factories may be established in existing buildings or new production facilities may be additionally established in existing factory spaces so as to expand a production capacity and update existing production lines to new production lines corresponding to up-to-date devices. In the transport system, the rail is generally installed in a horizontal direction in the vicinity of the ceiling and thus the OHT carriage moves in the horizontal direction. It may be necessary to give a level difference to the rail in stalled on the ceiling at the time of establishing the new factories and facilities.
In the transport system disclosed in the above publication, a plurality of rail members constituting the rail are disposed to be inclined in accordance with the level difference in portions of the rail of which the level varies. At this time, it is necessary to dispose the rail members while checking an inclination angle of the rail members, thereby increasing the number of installation processes and making a working error easily occur. In order to form a smoothly curved rail, it is necessary that the rail members disposed in the varied portions are shorter than rail members disposed in the horizontal direction and inclined portions are formed by the use of a plurality of the short rail members, thereby increasing the number of processes of suspending the rail on the ceiling in the inclined portions.

SUMMARY

It is therefore one advantageous aspect of the invention to provide a traveling rail for a carriage having a level difference but capable of reducing the number of processes and working errors.
According to one aspect of the invention, there is provided a carriage traveling rail, to which a carriage is movably attached, comprising:
a plurality of suspenders, upper ends of which are fixed to a ceiling, extending downward;
a first linear rail member, elongated in one direction and suspended by the suspenders which are arranged with a prescribed interval; and
a curved rail module, being curved in a vertical plane and elongated in the curved direction, the curved rail module suspended by the suspenders which are arranged with a prescribed interval and comprising:
a curved member, having a curved face which is curved in the vertical plane along the elongated direction; and
a plurality of second linear rail members, elongated in one direction and fixed to the curved member, the second rail members being shorter than the first linear rail member in length relative to the elongated direction, wherein:
the second linear rail members are in contact with the curved face while being so arranged that adjacent ones of the second linear members are elongated in directions different from each other and end faces in the elongated direction of the adjacent ones of the second linear members oppose each other, so that the carriage travels while being guided by the second linear rail members.
With this configuration, when the carriage traveling rail has a level difference, portions of which the level varies can be connected by the use of a curved rail module. Here, the curved rail module can be formed by arranging a plurality of second linear rail members in contact with a curved face and fixing the second linear rail members to a curved member. Accordingly, at the time of forming the portions of the traveling rail of which the level varies, it is not necessary to check the inclination angles for the second linear rail members, thereby reducing the number of processes and making the working error difficult to occur. In the curved rail module, since the plurality of second linear rail members are fixed to the curved member, the curved rail module can be suspended on a ceiling by supporting the curved rail module by the use of a suspender at prescribed intervals and it is not necessary to individually support the plurality of second linear rail members by the use of the suspenders. Accordingly, the number of suspenders is small and the number of processes of suspending the curved rail module is decreased.
The curved member may be either a convex curved member in which the curved face is convex toward the second linear rail members or a concave curved member in which the curved face is convex toward an opposite side of the second linear rail members.
With this configuration, even when the curved member can be placed only at any one of an upside and a lower side of the second linear rail member, both a curved rail module curved to be upwardly convex and a curved rail module curved to be downward concave can be manufactured by the use of a convex curved member and a concave curved member as the curved members, thereby connecting all the portions of the carriage traveling rail of which the level varies by the use of the curved rail modules.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram showing a transport system 1 according to one embodiment of the invention.
FIG. 2 is a side view showing a carriage traveling rail in FIG. 1.
FIG. 3 is a schematic perspective view showing a first linear rail member in FIG. 2.
FIGS. 4A and 4B are schematic perspective views showing curved rail modules in FIG. 2.
FIG. 5 is a section view showing a connecting part between a second linear rail and a concave-curved member and a connecting part between the second linear rail and a convex-curved member in FIG. 4.
FIG. 6 is a side view showing the linear rail member and an OHT carriage viewed from a direction that the OHT carriage is transported.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

Hereinafter, exemplary embodiments of the invention will be described with reference to the accompanying drawings.
FIG. 1 is a diagram schematically illustrating a configuration of a transport system according to an embodiment of the invention. A transport system 1 is installed in a clean room for manufacturing a semiconductor. As shown in FIG. 1, the transport system 1 includes a carriage traveling rail 2 and an OHT carriage 5. The OHT carriage 5 moves along the carriage traveling rail 2, and thus workpieces are transported in each manufacturing process and between manufacturing processes.
The carriage traveling rail 2 includes an interprocess rail 6, a plurality of branch rails 7, and a plurality of intraprocess rails 4. The interprocess rail 6 is an annular rail extending in a vertical direction of FIG. 1 on the left side of a plurality of bays 9 arranged in the vertical direction of FIG. 1 to perform processes at the time of manufacturing a semiconductor. The carriage 5 moves between the bays 9 along the interprocess rails 6. A plurality of the branch rails 7 are rails branched from the interprocess rail 6 in correspondence with the plurality of bays 9. The carriage 5 moves from the interprocess rail 6 to the branch rail 7 corresponding to the bay 9 of a transport destination and then, moves up to the upside of each bay 9 along the branch rail 7. A plurality of the intraprocess rails 4 are connected to the plurality of branch rails 7 and extend on each bay 9 in an annular pattern. A semiconductor manufacturing equipment 36 for manufacturing a semiconductor and a stocker 37 for stocking a FOUP (Front-Opening Unified Pod) 34 (see FIG. 6) transported by the OHT carriage 5 are provided in each bay 9. A port 35 for loading and unloading the FOUP 34 (see FIG. 6) is provided in the semiconductor manufacturing equipment 36. An unloading port 38 and a loading port 39 for loading and unloading the FOUP 34 to and from the stocker 37 are provided in the stocker 37. The OHT carriage 5 moves to the upsides of the port 35, the unloading port 38, and the loading port 39 along the intraprocess rail 4. Accordingly, as described below, parts manufactured in one bay 9 for performing a process can be loaded on the FOUP 34 (see FIG. 6) and transported to another bay 9 for performing another process.
Next, a structure of the carriage traveling rail 2 is described with reference to FIGS. 2 to 5. FIG. 2 is a side view of the carriage traveling rail 2 of FIG. 1. FIG. 3 is a schematic perspective view of a first linear rail member 8 of FIG. 2. FIG. 4A is a schematic perspective view of a curved rail module 41 of FIG. 2 and FIG. 4B is a schematic perspective view of a curved rail module 42 of FIG. 2. FIG. 5 is a section view of a connecting part between a concave-curved member 10 and a second linear rail member 12 of FIG. 4A and a connecting part between a convex-curved member 11 and the second linear rail member 12 of FIG. 4B.
As shown in FIG. 2, the carriage traveling rail 2 includes a first linear rail member 8, the two kinds of curved rail modules 41 and 42, and a suspender 14. As shown in FIG. 3, the first linear rail member 8 has a rectangular parallelepiped outer shape and has openings 8 b on two end faces in an elongated direction thereof. There is formed a space 8 a extending in the elongated direction of the first linear rail member 8 and having a slit 8 c both ends of which are connected to the two openings 8 b on the lower face of the first linear rail member 8. As described below, a primary coil 21, a primary core 23, secondary coils 24, branch rollers 27, and traveling wheels 28 (see FIG. 6) of the OHT carriage 5 move within the space 8 a.
As shown in FIGS. 2 and 4A, the curved rail module 41 includes five second linear rail members 12 and a concave-curved member 10. The curved rail module 41 is curved within a vertical face and elongates in a curved direction. The second linear rail member 12 has a substantially rectangular parallelepiped outer shape having a length in the elongated direction smaller than that of the first linear rail member 8. The second linear rail members 12 have openings 12 b formed on two end faces in the elongated direction thereof. There is formed a space 12 a extending in the elongated direction of the second linear rail member 12 and having a slit 12 c both end of which is connected to the two openings 12 b on the lower face of the second linear rail member 12. As described below, the primary coil 21, the primary core 23, the secondary coils 24, the branch rollers 27, and the traveling wheels 28 (see FIG. 6) of the OHT carriage 5 move within the space 12 a.
The concave-curved member 10 has a flat upper face and a lower curved face 10 a smoothly curved within the vertical face to be convex upward along the elongated direction (convex in a direction away from the second linear rail members 12). The five second linear rail members 12 are fixed to the concave-curved member 10 in contact with the curved face 10 a so that elongated directions of adjacent second linear rail members 12 are different from each other. The openings 12 b (end faces in the elongated direction) of the adjacent second linear rail members 12 are connected to be opposed to each other. Here, a gap is provided between the openings 12 b of the adjacent second linear rail members 12. However, since the gap is small, the carriage 5 is guided and moved to the five second linear rail members 12 beyond the gap (beyond the openings 12 b of the adjacent second linear rail members 12). The gap does not cause an actual problem. A profile of an end face of the second linear rail members 12 is adjusted so as to prevent the gap from being produced. The five second linear rail members 5 form a smoothly curved rail along the curved 10 a as a whole. As shown in FIG. 5, the second linear rail member 12 and the concave-curved member 10 are fixed to each other by mounting, from a side of the concave-curved member 10, a nut 16 on a bolt 15 extending through the second linear rail member 12 and the concave-curved member 10 from a ceiling face of the space 12 a of the second linear rail member 12. Here, the second linear rail member 12 and the concave-curved member 10 are fitted into each other by the use of the bolt 15 and the nut 16 with a washer 19 disposed below the ceiling face, and a washer 17 and a spring washer 18 disposed on the concave-curved member 10 interposed therebetween.
As shown in FIGS. 2 and 4B, the curved rail module 42 includes five second linear rail members 12 and a convex-curved rail member 11. The curved rail module 42 is curved within the vertical face and elongates in the curved direction. The second linear rail members 12 of the curved rail module 42 are the same as those of the curved rail module 41. The convex-curved rail member 11 has a flat upper face and a lower curved face 11 a smoothly curved within the vertical face to be convex downward along the elongated direction (convex toward the second linear rail members 12). The five second linear rail members 12 are fixed to the convex-curved member 11 in contact with the curved face 11 a so that elongated directions of adjacent second linear rail members 12 are different from each other. The openings 12 b (end faces in the elongated direction) of the adjacent second linear rail members 12 are connected to be opposed to each other. Here, the gap is provided between the openings 12 b of the adjacent second linear rail members 12, but the gap is small and the carriage 5 is guided and moved to the five second linear rail members 12 beyond the gap. The profile of the end face of the second linear rail members 12 is adjusted so as to prevent the gap from being produced. The five second linear rail members 12 form the smoothly curved rail along the curved 11 a as a whole. As shown in FIG. 5, the second linear rail member 12 and the convex-curved member 11 are fixed to each other by the use of the bolt 15, the nut 16, the washers 17 and 19, and the spring washer 18 in the same manner as the second linear rail member 12 and the concave-curved member 10.
Upper ends of a plurality of suspenders 14 are fixed to the ceiling. The suspenders 14 extend downward from the upper end. Lower ends of the suspenders 14 are fixed to both ends of the first linear rail member 8 in the elongated direction and fixed to the second linear rail member 12 located at both ends of the curved rail modules 41 and 42 in the elongated direction (supported at prescribed intervals). According to this configuration, the first linear rail member 8, and the curved rail modules 41 and 42 are suspended on the ceiling by the suspenders 14.
As shown in FIG. 2, the carriage traveling rail 2 is formed of a rail having the level difference. The plurality of first linear rail members 8 are disposed and the openings 8 b of the adjacent first linear rail members 8 are connected to each other in portions of the carriage traveling rail 2 having a constant level, which extends in the horizontal direction. In the portions of the traveling rail 2 of which the level varies, the curved rail module 41 is disposed adjacent to the first linear rail member 8 located in a higher position, and the opening 8 b and the opening 12 b are connected to each other, and the curved rail module 42 is disposed adjacent to the first rail member 8 located in a lower position, and the opening 8 b and the opening 12 b are connected to each other. The curved rail modules 41 and 42 are connected to each other with the first linear rail member 8 interposed therebetween.
Here, the curved rail modules 41 and 42 can be formed by arranging the five second linear rail members 12 on the curved face 10 a and the curved face 11 a and fixing the five second linear rail members 12 to the concave-curved member 10 and the convex-curved member 11. The portions of the carriage traveling rail 2 of which the level varies can be connected by the use of the curved rail modules 41 and 42, and thus it is not necessary to dispose the second linear rail members 12 while checking the inclination angles of the second linear rail members 12 in the portions of the traveling rail 2 of which the level varies. Accordingly, the number of processes of suspending the curved rail module is decreased and a working error is difficult to occur. In the curved rail modules 41 and 42, since the five second rail members 12 are fixed to each of the concave-curved member 10 and the convex-curved member 11, it is possible to suspend the curved rail modules 41 and 42 by fixing two second linear rail members 12 located at both ends of each of the curved rail modules 41 and 42 in the elongated direction to the lower ends of the suspenders 14 (by supporting the curved rail modules 41 and 42 by the use of the suspenders 14 at the prescribed intervals). Accordingly, it is not necessary to individually suspend the five second linear rail members 12 by the use of the suspenders 14, and thus the number of the suspenders 14 may be small and the number of the working processes of suspending the curved rail modules 41 and 42 is decreased.
Next, the OHT carriage 5 is described with reference to FIG. 6. FIG. 6 is a side view of the linear rail members 8 and 12, and the OHT carriage 5 as viewed in a transport direction of the OHT carriage 5. In order to easily understand FIG. 6, the space 8 a (the space 12 a) in FIG. 6 is drawn larger than that in FIGS. 3 to 5.
As shown in FIG. 6, the OHT carriage 5 includes the primary coil 21, the primary core 23, the two secondary coils 24, the two branch rollers 27 and the two traveling wheels 28 which move within the spaces 8 a and 12 a, and a positioning mechanism 29, a suspension belt 30 and a hoist 31 which extend downward beyond openings 8 c and 12 c.
The primary coil 21 and the primary core 23 are provided in a substantially center of the OHT carriage 5 in a plan view. Meanwhile, in the linear rail members 8 and 12, a secondary permanent magnet 22 extending in the elongated direction is placed in a substantially center of the ceiling faces of the spaces 8 a and 12 a in correspondence with the primary coil 21 and the primary core 23.
The two secondary coils 24 are formed in the vicinity of two lateral faces of each of the spaces 8 a and 12 a in a direction perpendicular to the elongated direction of each of the linear rail members 8 and 12. Meanwhile, two primary power feeders 25 extending in the elongated direction of each of the linear rail members 8 and 12 are provided on the two lateral faces of each of the linear rail members 8 and 12 in correspondence with the secondary coils 24.
A power supplied to the primary power feeders 25 is supplied to the OHT carriage 5 as a conductive power conducted to the secondary coil 24 in a non-contact manner. A linear motor including the primary coil 21, the primary core 23 and the secondary permanent magnet 22 generates a traveling thrust of the OHT carriage 5.
The two branch rollers 27 are placed below each of the secondary coils 24. Meanwhile, branch guides 26 are formed adjacent to a branch point (see FIG. 2) between the interprocess rail 6 and the branch rail 7, which protrude in the horizontal direction from the same lateral face as a face on which the primary power feeder 25 is provided below the primary power feeder 25 in correspondence with the branch roller 27, have a profile of an end face curved downward at an end and extend in the elongated direction of the linear rail members 8 and 12. The two branch rollers 27 are integrally movable in the horizontal direction shown in FIG. 6. Only one of the two branch rollers 27 selectively engages with the corresponding branch guide 26. According to this configuration, it is possible to choose whether or not to move the OHT carriage 5 to the branch rail 7 from the interprocess rail 6.
The two traveling wheels 28 are respectively provided below the two branch rollers 27. A diameter of each of the two traveling wheels has a size exceeding the gap produced between the openings 12 b of the adjacent second linear rail members 12 in the above-mentioned curved rail modules 41 and 42. The traveling wheels 28 are supported on bottom faces of the spaces 8 a and 12 a. The traveling wheels 28 move within the spaces 8 a and 12 a with the primary coil 21, the primary core 23, the secondary coils 24 and the branch roller 27 by rotation of the traveling wheels 28. According to this configuration, the OHT carriage 5 moves along the linear rail members 8 and 12.
The positioning mechanism 29 performs a positioning operation between the OHT carriage 5 and the port 35. The suspension belt 30 extends downward from a lower face of the positioning mechanism 29. The hoist 31 is mounted on a lower end of the suspension belt 30. The hoist 31 is movable in the vertical direction by rolling up or down the suspension belt 30.
A gripper 32 for gripping the FOUP 34 is provided on a lower face of the hoist 31. The FOUP 34 is a box in which a semiconductor substrate such as a silicon wafer internally transported can be put. A flange 33 engaging in the gripper 32 is formed on an upper face of the FOUP 34. The gripper 32 grips the FOUP 34 by engagement with the flange 33 and during the FOUP 34 is transported and the gripper 32 places the FOUP 34 on the port 35 and the loading port 39 by disengagement from the flange 33 when the FOUP 34 arrives at the port 35 and the loading port 39 of a transport destination.
Here, a transporting operation of the FOUP 34 performed by the OHT carriage 5 is described. At the time of transporting the FOUP 34, the OHT carriage 5 first moves to the upside of the port 35 at which the FOUP 34 to be transported is placed along the carriage traveling rail 2. The OHT carriage 5 is positioned by the positioning mechanism 29 at the upside of the port 35 of the transport destination. When the positioning operation is completed, the suspension belt 30 is released and the hoist 31 moves downward until the gripper 32 is brought contact with the flange 33 of the FOUP 34. The gripper 32 engages with the flange 33, and then the suspension belt 30 is rolled up.
Next, the OHT carriage 5 moves to the upside of the port 35 of the transport destination along the carriage traveling rail 2. The OHT carriage 5 is positioned by the positioning mechanism 29 at the upside of the port 35 of the transport destination. When the positioning operation is completed, the suspension belt 30 is released and the hoist 31 moves downward to the port 35 with the FOUP 34. At the time when the lower face of the FOUP 34 reaches the port 35, the FOUP 34 is placed on the port 35 by disengagement of the gripper 32 from the flange 33. After then, the OHT carriage 5 rolls up the suspension belt 30 and moves along the carriage traveling rail 2 in accordance with a subsequent command. An operation of taking the FOUP 34 out of the unloading port 38 and an operation of transporting the FOUP 34 to the loading port 39 are the same as the transporting operation of the FOUP 34 performed by the OHT carriage 5. Accordingly, a description thereof will be omitted.
According to the embodiment described above, when the carriage traveling rail 2 is disposed with the level difference, the portions of the carriage traveling rail 2 of which the level varies can be connected by the use of the curved rail modules 41 and 42. Here, since the curved rail modules 41 and 42 can be formed by arranging the five second linear rail members in contact with the curved faces 10 a and 11 a, and by fixing the five second linear rail members to the curved members 10 and 11, it is not necessary to check the inclination angle for each second linear rail member 12, and thus the number of working processes is decreased and the working error is difficult to occur at the time of forming the portions of the traveling rail of which the level varies.
In the curved rail modules 41 and 42, since the five second linear rail members 12 are fixed to each of the concave-curved member 10 and the convex-curved member 11, it is possible to suspend the curved rail modules 41 and 42 on the ceiling by fixing the second linear rail members 12 located at both ends of each of the curved rail modules 41 and 42 in the elongated direction to the lower ends of the suspenders 14. Accordingly, it is not necessary to suspend the five second linear rail members 12 by the use of the suspenders 14 separately, and thus the number of the suspenders 14 may be small and the number of the processes for suspending the curved rail modules 41 and 42 is decreased.
The curved rail module 41 having a rail curved to be convex upward and the curved rail module 42 having a rail curved to be convex downward can be formed by using the concave-curved member 10 and the convex-curved member 11 as the curved member. Accordingly, even when the curved member can be provided only at the upside of the second linear rail member 12, all the portions of the carriage traveling rail 2 of which the level varies can be connected by the use of the curved rail modules 41 and 42.
In the above-mentioned description, the preferred embodiment of the invention has been described, but the invention is not limited to the above-mentioned embodiment. Various changes and modifications may be made within the scope without departing from the claims. For example, in the embodiment, the five second linear rail members 12 are used to form each of the curved rail modules 41 and 42, but the number of the second linear rail members 12 is not limited to five. An optimum design value selected in accordance with the degree of the rail level difference, and lengths of the curved face 10 a and the second linear rail members 12 in the elongated direction may be applied to the number of the second linear rail members 12.
In the embodiment, in the portions of the carriage traveling rail 2 of which the level varies, the curved rail module 41 is connected to the first linear rail member 8 located at the higher position, the curved rail module 42 is connected to the first linear rail member 8 located at the lower position and the first linear rail member 8 is connected between the curved rail modules 41 and 42, but the invention is not limited to them. The curved rail module 41 may be directly connected to the curved rail module 42 in portions of carriage traveling rail 2 having a small level difference. On the contrary, the plurality of curved rail modules 41 and the plurality of curved rail modules 42 each may be continuously connected in portions of the carriage traveling rail 2 having a large level difference.
In the embodiment, the carriage traveling rail 2 for transporting the OHT carriage 5 is described, but the invention may be applied to carriage traveling rails for transporting other kinds of carriages such as an OHS (Over Head Shuttle).
In the above-mentioned description, the printer according to the embodiment has been described, but the invention is not limited to all the above-mentioned embodiments. Various changes and modifications may be made within the scope without departing from the claims.
The disclosure of Japanese Patent Application No. 2006-187670 filed Jul. 6, 2006 including specification, drawings and claims is incorporated herein by reference in its entirety.

Claims

1. A carriage traveling rail, to which a carriage is movably attached, comprising:

a plurality of suspenders, each of which is extended downward from a ceiling;

a first linear rail member, having a first longitudinal dimension and suspended by the suspenders; and

a curved rail module, comprising:

a curved member, suspended by the suspenders and having a curved face which is curved in a vertical plane along an elongated direction thereof; and

a plurality of second linear rail members, each of which is fixed to the curved member and has a second longitudinal dimension shorter than the first longitudinal dimension, wherein:

the second linear rail members are arranged along the curved face such that adjacent ones of the second linear members are elongated in directions different from each other and longitudinal end faces of the adjacent ones of the second linear members oppose each other.

2. The carriage traveling rail as set forth in claim 1, wherein the curved member is either a convex curved member in which the curved face is convex toward the second linear rail members or a concave curved member in which the curved face is convex concaved from the second linear rail members.