Overhead transport vehicle system

Abstract

The overhead transport vehicle system (1) includes: an overhead transport vehicle (6), which has a traveling section (50) with traveling wheels (51) and a main body section (7) supported on the traveling section (50) by means of a suspension section (8) and holding the transported object (10); and a cylindrical traveling track (4), which has a slit section (G) for the suspension section (8) to move when the traveling section (50) travels and a rolling section (41) for the traveling wheels (51) to roll, and forms an internal space (S) for the traveling section (50) to travel. In the internal space (S) of the traveling track (4) in the curved section (4C), above the passage area (R) for the traveling wheels (51) rolling on the outside of the curve to pass through, a levitation limiting section (81) is arranged along the extension direction of the traveling track (4) for contact with the traveling wheels (51) that are levied from the rolling section (41) by a predetermined amount.

Description

[Technical Field]

[0001] One aspect of the present invention relates to an overhead transport vehicle system. [Previous Technology]

[0002] Overhead transport vehicles that travel along tracks installed on the ceilings of buildings such as factories are known. For example, Patent Document 1 (International Publication No. 2012 / 157319) discloses an overhead transport vehicle having a traveling section that travels on the tracks and a main body section that holds articles. In the overhead transport vehicle of Patent Document 1, the traveling section travels inside the cylindrical track, which is formed into a square tube, and the main body section is suspended and supported relative to the traveling section by means of a slit provided on the lower surface of the track.

[0003] In this type of overhead transport vehicle, sometimes a portion of the traveling wheels that make up the traveling section may float up due to centrifugal force when traveling in curved sections, causing the traveling section to tilt. In this case, there is a risk of collision between various parts of the traveling section and the traveling track, and damage to various parts of the traveling section. [Summary of the Invention]

[0004] [The problem the invention aims to solve]

[0005] Therefore, one objective of the present invention is to provide an overhead transport vehicle system capable of suppressing the lifting amount of the traveling wheels when the traveling unit travels in a curved section. [Technical means for solving the problem]

[0006] One aspect of the overhead transport vehicle system of the present invention includes: an overhead transport vehicle having a traveling section with traveling wheels and a main body section supported on the traveling section by means of a suspension section and holding the transported object; and a cylindrical traveling track having a slit section for the suspension section to move when the traveling section travels and a rolling section for the traveling wheels to roll, and forming an internal space for the traveling section to travel; in the internal space of the traveling track in a curved section, above a passage area for the traveling wheels rolling on the outside of the curve to pass through, a levitation limiting section is arranged along the extending direction of the traveling track for contact with the traveling wheels that are levied from the rolling section by a predetermined amount.

[0007] In this overhead transport vehicle system, within the internal space of the travel track in the curved section, a buoyancy limiting part is arranged along the extending direction of the travel track, allowing the travel wheel on the outer side of the curve to contact the track when it rises a predetermined amount from the rolling part. This prevents the travel wheel on the outer side of the curve from rising from the rolling part by more than a predetermined amount in the curved section. Therefore, the amount of buoyancy of the travel wheel when the traveling unit travels in the curved section can be suppressed.

[0008] In one embodiment of the overhead transport vehicle system of the present invention, the traveling track may have a side portion that intersects with the rolling portion, and the levitation limiting portion may protrude from the side portion toward the interior space. In this structure, the levitation limiting portion can be easily formed using the side portion of the traveling track.

[0009] In one embodiment of the overhead transport vehicle system of the present invention, the overhead transport vehicle may further include a forked roller for branching at a branching point of the travel track. The forked roller and the lifting restraint of the overhead transport vehicle traveling on the travel track are arranged opposite each other in a width direction orthogonal to both the extension direction and the vertical direction of the travel track. The lifting restraint has an end face opposite to the forked roller, and a conical surface is provided in the internal space of the straight section, which connects the end face and the side face when viewed from above in the vertical direction. In this structure, even when the forked roller of the overhead transport vehicle reaches the entrance of the curved section while maintaining a state that is outside the end face of the lifting restraint when viewed from above, the forked roller will not collide with the end face of the lifting restraint in the extension direction, but will be smoothly guided to the end face of the lifting restraint by the conical surface. Thus, damage to at least one of the forked roller and the lifting restraint can be prevented.

[0010] In one embodiment of the overhead transport vehicle system of the present invention, the overhead transport vehicle may also have a control unit that controls each part of the traveling section, the forked rollers being arranged in a manner that allows them to move in the width direction, and the control unit controlling the forked rollers to move in the width direction towards the inside of the curve before or simultaneously with the traveling section entering the curve. In this structure, damage to at least one of the forked rollers and the lifting restraint due to collision between the forked rollers and the lifting restraint can be prevented more reliably. [Effects of the Invention]

[0011] According to one aspect of the present invention, the amount of wheel lift-up when the walking unit travels in a curved section can be suppressed.

Implementation Method

[0013] Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings. It should be noted that in the description of the drawings, the same elements are labeled with the same reference numerals and repeated descriptions are omitted. In Figures 2 and 3, the directions "up", "down", "left", "right", "front", and "rear" are defined for ease of explanation.

[0014] As shown in Figures 1 and 2, the overhead conveyor system 1 is a system for transporting items (transported objects) 10 between loading units 9 using overhead conveyor 6 (hereinafter referred to as "conveyor 6") that can move along the travel track 4. Items 10 include, for example, containers such as FOUPs (Front Opening Unified Pods) for storing multiple semiconductor wafers and marking cassettes for storing glass substrates, as well as general parts. The overhead conveyor system 1 includes the travel track 4, multiple conveyor 6s, and multiple loading units 9.

[0015] As shown in FIG1, the mounting section 9 is arranged along the travel track 4 and is located at a position where the transport vehicle 6 can transfer the item 10. The mounting section 9 includes a buffer zone and an interface. The buffer zone is a mounting section for temporarily mounting the item 10. The buffer zone is a mounting section for temporarily mounting the item 10 when it is impossible to transfer the item 10 being transported by the transport vehicle 6 to the interface because other items 10 are mounted at the target interface. The interface is a mounting section for transferring the item 10 to a semiconductor processing device (not shown), such as a cleaning device, a film deposition device, a photolithography device, an etching device, a heat treatment device, or a planarization device. It should be noted that the processing device is not particularly limited and can be various devices.

[0016] For example, the loading section 9 is positioned to the side of the travel track 4. In this case, the transport vehicle 6 uses the lateral delivery section 24 to laterally deliver the lifting drive section 28 and the like, and raises and lowers the lifting platform 30, thereby transferring the item 10 between itself and the loading section 9. It should be noted that, although not shown, the loading section 9 may also be positioned directly below the travel track 4. In this case, the transport vehicle 6 transfers the item 10 between itself and the loading section 9 by raising and lowering the lifting platform 30.

[0017] The travel track 4 is, for example, laid near the ceiling, which serves as overhead space for workers. The travel track 4 is, for example, suspended from the ceiling. The travel track 4 is a predetermined travel path for the transport vehicle 6 to travel. The transport vehicle 6 moves in a predetermined direction on the travel track 4. The travel track 4 is supported by supports 4A, 4A.

[0018] As shown in Figures 2 and 3, the travel track 4 has: a cylindrical track body 40, which is composed of a pair of lower surface portions (rolling portions) 41, 41, a pair of side portions 42, 42, and an upper surface portion 43; a power supply portion 45; and a magnetic plate 46. The track body 40 forms an internal space S for the travel portion 50 of the transport vehicle 6 to travel. The lower surface portion 41 extends along the travel direction of the transport vehicle 6 and constitutes the lower surface of the track body 40. The lower surface portion 41 is a plate-shaped component for the travel rollers (travel wheels) 51 of the transport vehicle 6 to roll, thereby causing the travel portion 50 to travel. The side portions 42 are erected (crossed) from the lower surface portion 41. The side portions 42 extend along the travel direction of the transport vehicle 6 and constitute the side of the track body 40. The upper surface portion 43 extends along the travel direction of the transport vehicle 6 and constitutes the upper surface of the track body 40.

[0019] Between a pair of lower surface portions 41, 41 facing each other in the width direction (left-right direction) orthogonal to the extension direction of the travel track 4, a slit G is formed for the suspension portion 8 of the travel portion 50, which will be described in detail later, to pass through during travel. The slit G extends along the extension direction of the travel track 4.

[0020] The power supply unit 45 supplies power to the power supply core 57 of the transport vehicle 6 and transmits and receives signals relative to the power supply core 57. The power supply unit 45 is fixed to a pair of side portions 42, 42, and extends along the travel direction. The power supply unit 45 supplies power to the power supply core 57 in a non-contact manner. The magnetic plate 46 causes the LDM (Linear DC Motor) 59 of the transport vehicle 6 to generate magnetic force for moving or stopping. The magnetic plate 46 is fixed to the upper surface portion 43 and extends along the travel direction.

[0021] The transport vehicle 6 travels along the track 4 and transports items 10. The transport vehicle 6 is configured to carry items 10. The transport vehicle 6 is an elevated unmanned transport vehicle. The number of transport vehicles 6 in the elevated transport vehicle system 1 is multiple and there is no particular limitation. The transport vehicle 6 has a main body 7, a traveling part 50, and a main controller (control part) 35. The main body 7 has a main frame 22, a lateral delivery part 24, an θ driver 26, a lifting drive part 28, a lifting platform 30, and a cover 33.

[0022] The main frame 22 is connected to the traveling unit 50 via the suspension part 8 and supports the lateral delivery part 24, the θ driver 26, the lifting drive part 28, the lifting platform 30, and the cover 33. The lateral delivery part 24 delivers the θ driver 26, the lifting drive part 28, and the lifting platform 30 laterally in a width direction (left-right direction) orthogonal to the traveling direction of the traveling track 4. The θ driver 26 causes at least one of the lifting drive part 28 and the lifting platform 30 to rotate in the horizontal plane within a predetermined angle range. The lifting drive part 28 raises and lowers the lifting platform 30 by winding or releasing lifting materials such as wires, ropes, and straps. A chuck is provided on the lifting platform 30 for freely gripping or releasing the item 10. The cover 33 is provided in pairs, for example, at the front and rear of the traveling direction of the transport vehicle 6. The cover 33 allows claws (not shown) to protrude to prevent the item 10 from falling during transport.

[0023] As shown in Figures 3 and 5, the traveling unit 50 enables the transport vehicle 6 to travel along the traveling track 4. The traveling unit 50 has two main bodies 50A and 50B, which are connected to each other. The two main bodies 50A and 50B each have a traveling roller 51, a side roller 52, a branch roller 53, an auxiliary roller 54, a tilting roller 55, a power supply core 57, and an LDM 59.

[0024] Traveling rollers 51 are disposed at the front and rear, left and right ends of the traveling section 50. The traveling rollers 51 roll on the inner surfaces 41a, 41a of a pair of lower surface portions 41, 41 of the track body 40. Side rollers 52 are disposed such that they clamp the traveling rollers 51 in the front-rear direction. The side rollers 52 are configured to contact the inner surface 42a of the side surface portion 42 of the track body 40.

[0025] The bifurcation roller 53 is arranged to sandwich the side roller 52 from above and below. The bifurcation roller 53 is provided for switching the transport vehicle 6 (traveling unit 50) to travel in a straight line or in a bifurcation at the bifurcation point of the traveling track 4. More specifically, the bifurcation roller 53 is selectively guided by a guide member provided at the bifurcation point to switch the traveling direction of the transport vehicle 6. Four bifurcation rollers 53 are provided relative to one main body 50A (50B). The bifurcation rollers 53 are mounted on a support member 53A that is movable in the width direction. The support member 53A is driven in the width direction by a drive unit 53B. That is, the four bifurcation rollers 53 move together in the width direction by the movement of the support member 53A. The drive of the drive unit 53B is controlled by the main body controller 35.

[0026] The side roller 52 is configured to contact a guide (not shown) disposed on the connecting part or branch part of the travel track 4. The auxiliary roller 54 is a group of three rollers disposed at the front and rear of the travel unit 50. The auxiliary roller 54 is provided to prevent the LDM 59 and the power supply core 57 from contacting the magnetic plate 46 disposed on the upper surface part 43 of the travel track 4 when the travel unit 50 tilts forward or backward due to acceleration or deceleration. The tilting roller 55 is disposed in a state tilted relative to the front-back direction. The tilting roller 55 is provided to prevent tilting caused by centrifugal force when the travel unit 50 travels in the curved section.

[0027] The power supply core 57 is arranged at the front and rear of the traveling unit 50 in a left-right direction, sandwiching the LDM 59, and performs non-contact power supply and non-contact signal transmission and reception with the power supply unit 45 arranged on the traveling track 4. The power supply core 57 exchanges signals with the main controller 35. The LDM 59 is located at the front and rear of the traveling unit 50. The LDM 59 generates a magnetic force for traveling or stopping by means of an electromagnet between itself and the magnetic plate 46 arranged on the upper surface part 43 of the traveling track 4.

[0028] The traveling unit 50 is controlled by the transport controller 90, which will be described in detail later, in a state with the aid of the main controller 35. Specifically, an instruction from the transport controller 90 is sent to the main controller 35, and the main controller 35, upon receiving the instruction, controls the traveling unit 50.

[0029] The main controller (control unit) 35 is an electronic control unit composed of a CPU (Central Processing Unit), ROM (Read Only Memory), and RAM (Random Access Memory). The main controller 35 controls various actions in the transport vehicle 6. Specifically, the main controller 35 controls the traveling unit 50, the lateral delivery unit 24, the θ driver 26, the lifting drive unit 28, and the lifting platform 30. The main controller 35 can be configured as software, for example, loading a program stored in ROM into RAM and having the CPU execute the program. The main controller 35 can also be configured as hardware based on electronic circuits, etc. The main controller 35 communicates with the transport controller 90 (see Figure 1) via the power supply unit 45 (feeder) of the traveling track 4.

[0030] The transport controller 90 is an electronic control unit consisting of a CPU, ROM, and RAM. The transport controller 90 communicates with the main controller 35 via wired or wireless means and sends transport instructions to the main controller 35 to make the transport vehicle 6 transport the item 10.

[0031] As shown in Figure 4, the travel track 4 is composed of a straight section 4S and a curved section 4C. As shown in Figures 2 to 4, in this embodiment, within the internal space S of the travel track 4 in the curved section 4C, above the passage area R through which the travel roller 51 rolling on the inner surface 41a of the lower surface portion 41 passes and below the upper surface portion 43, a buoyancy restriction portion 81 is arranged along the extending direction of the travel track 4 for contact with the travel roller 51 that is buoyed up from the lower surface portion 41 by a predetermined amount. The buoyancy restriction portion 81 extends from the inner surface 42a of the side surface portion 42 towards the internal space S to its top end. In other words, the top end of the buoyancy restriction portion 81 protrudes towards the internal space S compared to the inner surface 42a of the side surface portion 42.

[0032] The levitation limiting part 81 is made of, for example, stainless steel, and can be integrally formed with the side part 42 or mounted relative to the side part 42 by means of a bracket or the like. It should be noted that the above-mentioned specified amount is appropriately set according to the amount of levitation of the traveling roller 51 corresponding to the collision state between the traveling track 4 and each part of the traveling part 50. That is, the amount of levitation is permissible when the traveling roller 51 is levied but the traveling track 4 and each part of the traveling part 50 do not collide.

[0033] It should be noted that, when viewed from above, the pair of side portions 42, 42 constituting the travel track 4, the outer side of the curve in the travel track 4 refers to the side portion 42 with the larger curve radius (smaller curvature), and the inner side of the curve in the travel track 4 refers to the side portion 42 with the smaller curve radius (larger curvature). Furthermore, in the lower surface portion 41, the side portion 42, and the upper surface portion 43, the surface that contacts the aforementioned internal space S is called the inner surface, and the surface on the opposite side of the inner surface, that is, the surface that contacts the external space, is called the outer surface.

[0034] The levitation limiting part 81 is provided in a way that it is opposite to the bifurcated roller 53 of the transport vehicle 6 traveling on the travel track 4 in the width direction. As shown in FIG3, the top end of the internal space S side of the levitation limiting part 81 is configured as an end face 81a. The vertical dimension of the end face 81a is larger than the vertical dimension of the bifurcated roller 53. That is, the end face 81a of the levitation limiting part 81 is configured to allow the bifurcated roller 53 to roll. A tapered part 83 is provided at the entrance and exit portions of the curved section 4C (i.e., the boundary portion of the straight section 4S with the curved section 4C). The tapered part 83 is also installed on the side portion 42 constituting the travel track 4 in the same way as the levitation limiting part 81.

[0035] The tapered portion 83 has a tapered surface 83a that smoothly connects the inner surface 42a of the side portion 42 to the end face 81a of the levitation limiting portion 81. The vertical dimension of the tapered surface 83a is larger than the vertical dimension of the bifurcated roller 53, and is approximately the same as the end face 81a. With this structure of the tapered portion 83, the bifurcated roller 53 can roll continuously on the inner surface of the side portion 42, the tapered surface 83a, and the end face 81a.

[0036] In this embodiment, the main controller 35 controls the bifurcation roller 53 to move in the width direction toward the inside of the curve (the position of the bifurcation roller 53 shown in FIG. 5) before or at the same time as the traveling part 50 enters the curve section 4C. More specifically, the main controller 35 controls the drive of the drive part 53B to move the support member 53A, thereby moving the bifurcation roller 53. In this embodiment, the main controller 35 moves the bifurcation roller 53 in the width direction to a position on the end face 81a of the levitation restriction part 81, or to a position that is closer to the inside of the end face 81a of the levitation restriction part 81.

[0037] The effects of the overhead transport vehicle system 1 according to the above embodiment will be explained. In the overhead transport vehicle system 1 according to the above embodiment, a levitation limiting part 81 is arranged in the internal space S of the travel track 4 in the curved section 4C. The levitation limiting part 81 is a part that the travel roller 51 on the outside of the curve contacts when it is levied from the lower surface part 41 by a predetermined amount, and is arranged along the extending direction of the travel track 4. As a result, it is possible to prevent the travel roller 51 on the outside of the curve from levying from the lower surface part 41 by a greater than predetermined amount in the curved section 4C. Therefore, it is possible to suppress the amount of levitation of the travel roller 51 when the travel unit 50 travels in the curved section 4C. As a result, for example, it is possible to suppress damage to at least one of the travel unit 50 (e.g., LDM 59, power supply core 57) and the travel track 4 (e.g., power supply part 45, magnetic plate 46).

[0038] In the overhead transport vehicle system 1 of the above embodiment, the levitation limiting part 81 is configured to protrude from the side part 42 toward the interior space S. Therefore, the levitation limiting part 81 can be easily constructed using the side part 42 of the travel track 4.

[0039] In the elevated transport vehicle system 1 of the above embodiment, the bifurcated roller 53 and the lifting restriction part 81 of the transport vehicle 6 traveling on the travel track 4 are arranged opposite each other in the width direction. The lifting restriction part 81 has an end face 81a opposite to the bifurcated roller 53, and a conical surface 83a is provided in the internal space S of the straight section 4S, which connects the end face 81a and the side surface 42 when viewed from above. Therefore, even when the bifurcated roller 53 of the transport vehicle 6 reaches the entrance of the curved section 4C while maintaining a state that is outside the end face 81a of the lifting restriction part 81 when viewed from above, the bifurcated roller 53 will not collide with the end in the extending direction of the lifting restriction part 81, but will be smoothly guided to the end face 81a of the lifting restriction part 81 by the conical surface 83a. Therefore, damage to at least one of the bifurcated roller 53 and the lifting restriction part 81 can be prevented.

[0040] In the elevated transport vehicle system 1 of the above embodiment, the main controller 35 can also control the bifurcation roller 53 to move in the width direction toward the inside of the curve before or at the same time as the traveling unit 50 enters the curve section 4C. This more reliably prevents damage to at least one of the bifurcation roller 53 and the floating restriction part 81 due to collision between the bifurcation roller 53 and the floating restriction part 81.

[0041] An embodiment has been described above, but the present invention is not limited to the above embodiment. Various modifications can be made without departing from the spirit of the invention.

[0042] In the above embodiment, an example was described in which the rolling surface for the traveling roller 51 to roll is configured as the lower surface portion 41 of the traveling track 4, but it is not limited to this. The rolling surface for the traveling roller 51 to roll may also be formed separately at a position above the lower surface of the traveling track 4.

[0043] In the above embodiments and variations, an example of moving the bifurcation roller 53 in the width direction before the transport vehicle 6 enters the curve section 4C has been described. However, such control is not necessary. In addition, the transport vehicle 6 does not necessarily have the bifurcation roller 53.

[0044] In the above embodiments and modifications, the example of the levitation limiting part 81 being installed on the side portion 42 of the travel track 4 has been described, but it is not limited to this. For example, the levitation limiting part 81 may also be configured to be suspended from the upper surface portion 43 of the travel track 4, as long as it is provided above the passage area R through which the travel roller 51, which rolls on the inner surface 41a of the lower surface portion 41, passes.

[0045] In the above embodiments and variations, an example was described in which the floating restriction part 81 is provided above the passage area R through which the traveling roller 51, which rolls on the outer side of the bend on the inner surface 41a of the lower surface part 41, passes. However, it is also possible to provide the floating restriction part 81 above the passage area through which the traveling roller 51, which rolls on the inner side of the bend on the inner surface 41a of the lower surface part 41, passes, based on this structure. [Simplified Explanation of the Diagram]

[0012] [Fig. 1] is a schematic structural diagram of an embodiment of an overhead transport vehicle system. [Fig. 2] is a front view of the overhead transport vehicle of Fig. 1. [Fig. 3] is an enlarged cross-sectional view of the travel track portion of Fig. 2. [Fig. 4] is a top view showing the configuration of the levitation limiting part. [Fig. 5] is a diagram showing the traveling part that travels within the internal space of the travel track.

Claims

1. An overhead transport vehicle system, characterized in that it comprises: an overhead transport vehicle having a traveling section with traveling wheels, a main body section supported on the traveling section by means of a suspension section and holding a transported object, and a branching roller for branching at a branching point of the traveling track; and a cylindrical traveling track having a slit section for the suspension section to move when the traveling section travels, and a rolling section for the traveling wheels to roll, and forming an internal space for the traveling section to travel; in the internal space of the traveling track in a curved section, above a passage area for the traveling wheels rolling on the outer side of the curve to pass through, a levitation limiting section is arranged along the extending direction of the traveling track for contacting the traveling wheels that are levied from the rolling section by a predetermined amount, the traveling track having a side section intersecting the rolling section, and the levitation limiting section protruding from the side section toward the internal space. The aforementioned bifurcated rollers and the aforementioned lifting restriction parts of the aforementioned overhead transport vehicle that travels on the aforementioned travel track are arranged to be opposite each other in a width direction orthogonal to both the extension direction and the vertical direction of the aforementioned travel track. The aforementioned lifting restriction part has an end face opposite to the aforementioned bifurcated rollers. A conical surface is provided in the aforementioned internal space in the straight section that connects the aforementioned end face and the aforementioned side face when viewed from above in the vertical direction.

2. The overhead transport vehicle system as described in claim 1, wherein, The aforementioned overhead transport vehicle has a control unit that controls each part of the aforementioned traveling unit. The aforementioned bifurcated roller is configured to be movable in the aforementioned width direction. The aforementioned control unit controls the aforementioned bifurcated roller to move inward toward the inside of the aforementioned curve in the aforementioned width direction before or at the moment the aforementioned traveling unit enters the aforementioned curved section.

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