JP7736026B2 - Overhead transport vehicle system - Google Patents

Description

The present invention relates to an overhead transport vehicle system.

One example of technology related to overhead transport vehicle systems is the transport system described in Patent Document 1. The transport system described in Patent Document 1 comprises a first overhead transport vehicle that travels on a first overhead track, a second overhead transport vehicle that travels on a second and third overhead track, a first placement unit (placement unit) that can transfer items between the first and second overhead transport vehicles, and a rotation mechanism that rotates the first placement unit around a vertical axis.

International Publication No. 2020/153041

In the above-mentioned system, the placement section can be rotated using a rotation mechanism, which improves the degree of freedom in the placement direction of items on the placement section. However, the rotation of the placement section requires more space around it than usual (when the placement section does not rotate).

The present invention aims to provide an overhead transport vehicle system that can improve the degree of freedom in the direction in which items are placed on the placement section without requiring any special space.

(1) The overhead transport vehicle system of the present invention comprises a track including a first track and a second track that travel in different directions, an overhead transport vehicle that travels along the track and has a holding section that holds an item in a predetermined orientation, and a loading section on which items are placed from the overhead transport vehicle on the first track and the overhead transport vehicle on the second track, wherein multiple recesses are formed on the bottom surface of the item, and the loading section has multiple protrusions that can fit into the recesses, and a protrusion changing device that changes the position of at least one of the multiple protrusions so that the protrusion fits into the recess depending on the orientation of the item to be placed on the loading section.

With this ceiling transport vehicle system, an item can be placed on the platform regardless of its orientation relative to the platform by simply changing the position of at least one of the multiple protrusions without rotating the platform. This increases the degree of freedom in the orientation in which an item can be placed on the platform without requiring any special space. As a result, the platform can be shared between multiple tracks traveling in different directions.

(2) The overhead transport vehicle system described in (1) above has a rotation mechanism that rotates the holding unit around a rotation axis along the vertical direction, and a control unit that controls the operation of the overhead transport vehicle, and the control unit of the overhead transport vehicle traveling on the first track may control the rotation mechanism so that the orientation of the item when unloading onto the placement unit matches a predetermined orientation for the overhead transport vehicle traveling on the second track that loads the item from the placement unit after unloading. In this case, the item can be loaded onto the placement unit in an orientation that corresponds to the next loading, making it possible to shorten the dwell time for holding the item in the holding unit when the next loading occurs.

(3) In the ceiling transport vehicle system described in (1) or (2) above, the placement section is provided with protrusions at positions corresponding to the multiple recesses of an item when the item is placed from the ceiling transport vehicle on the first track, and at positions corresponding to the multiple recesses of the item when the item is placed from the ceiling transport vehicle on the second track, and the protrusion changing device may cause a protrusion that comes into contact with a position on the bottom surface of the item that is not a recess to sink due to the weight of the item. In this case, the position of the protrusion can be changed with a simple mechanism.

(4) In the overhead transport vehicle system described in any one of (1) to (3) above, the height of the first track and the height of the second track may be the same, and the traveling direction of the first track and the traveling direction of the second track may be opposite. In this case, it is possible to transfer articles via the placement unit between the first track and the second track, which are at the same height and traveling in opposite directions.

(5) In the overhead transport vehicle system described in any one of (1) to (3) above, the height of the first track and the height of the second track may be different. In this case, it is possible to transfer items between the first track and the second track, which are at different heights, via the loading section.

(6) In the ceiling transport vehicle system described in any one of (1) to (5) above, the ceiling transport vehicle has a main body, a rotation mechanism that rotates the holding unit around a rotation axis along the vertical direction, a lifting drive unit that raises and lowers the holding unit, a lateral feed mechanism that moves the lifting drive unit laterally from the main body, and a control unit that controls the operation of the ceiling transport vehicle, wherein the center-to-center distance between the second track and the transfer position of the placement unit is smaller than the center-to-center distance between the first track and the transfer position of the placement unit, and when placing an item from the ceiling transport vehicle on the first track onto the placement unit, the control unit may rotate the holding unit using the rotation mechanism, and then move the lifting drive unit laterally using the lateral feed mechanism until the item is positioned above the transfer position of the placement unit, and then lower the holding unit using the lifting drive unit.

In this case, because the center-to-center distance between the second track and the placement unit's transfer position is smaller than the center-to-center distance between the first track and the placement unit's transfer position, when placing an item from the overhead transport vehicle on the first track onto the placement unit, if the holding unit is rotated at the placement unit's transfer position to rotate the item, the rotating item may be prone to interference with the overhead transport vehicle traveling on the second track. Therefore, by rotating the holding unit to a position where the item's rotation trajectory does not interfere with the overhead transport vehicle traveling on the second track, and then moving the lifting drive unit laterally until the item is positioned at the transfer position, it is possible to avoid such interference.

This invention makes it possible to provide an overhead transport vehicle system that improves the degree of freedom in the direction in which items are placed on the placement section without requiring any special space.

FIG. 1 is a perspective view showing a storage shelf and tracks on both sides of the shelf in an overhead transport vehicle system according to one embodiment. FIG. 2 is a bottom view of the article. FIG. 3 is a plan view showing the placement unit. FIG. 4 is an enlarged cross-sectional view of a part of the convex portion changing mechanism. Fig. 5(a) is a plan view illustrating the case where an article is transferred from the ceiling transport vehicle on the first track to the placement unit. Fig. 5(b) is a plan view showing a continuation of Fig. 5(a). Fig. 5(c) is a plan view showing a continuation of Fig. 5(b). Fig. 6(a) is a plan view showing a continuation of Fig. 5(c), Fig. 6(b) is a plan view showing a continuation of Fig. 6(a), and Fig. 6(c) is a plan view showing a continuation of Fig. 6(b). Fig. 7(a) is a plan view illustrating the case where an article is transferred from the ceiling transport vehicle on the second track to the placement unit. Fig. 7(b) is a plan view showing a continuation of Fig. 7(a). Fig. 7(c) is a plan view showing a continuation of Fig. 7(b). Fig. 8(a) is a plan view showing a continuation of Fig. 7(c), Fig. 8(b) is a plan view showing a continuation of Fig. 8(a), and Fig. 8(c) is a plan view showing a continuation of Fig. 8(b). 9A and 9B are plan and side views showing a modified convex portion changing device, respectively;

Embodiments will be described in detail below with reference to the drawings. In the description of the drawings, identical or equivalent elements will be designated by the same reference numerals, and duplicate explanations will be omitted.

As shown in FIG. 1, the ceiling transport vehicle system 1 is a system for transporting an item 10 using a ceiling transport vehicle 6 that can move along a track 4. The item 10 is, for example, a FOUP (Front Opening Unified Pod) that accommodates multiple semiconductor wafers. The item 10 may also be a container for storing multiple semiconductor wafers, a container for storing glass substrates, a reticle pod, a general component, or the like. As shown in FIG. 2, the bottom surface 10a of the item 10 is formed with multiple recesses 10h that are arranged so that their positional relationship with the mounting section 8 changes depending on the orientation of the item 10. The recesses 10h are spaces into which the protrusions 2, described below, fit. The recesses 10h are formed in a shape that corresponds to the protrusions 2, described below. The recesses 10h are arranged at three points on the bottom surface 10a that are not aligned in a straight line. The multiple recesses 10h do not have 180-degree rotational symmetry (dual-fold symmetry) with the vertical direction as the rotation axis. The multiple recesses 10h do not have 90-degree rotational symmetry (four-fold symmetry) with the vertical direction as the rotation axis.

As shown in FIG. 1, the overhead transport vehicle system 1 includes a track 4, multiple overhead transport vehicles 6, and multiple storage shelves 40. The track 4 is installed near the ceiling, which provides overhead space for workers in a factory or the like. The track 4 is suspended and supported, for example, by track supports 5. The track 4 includes a first track 4A and a second track 4B that are parallel to each other. A storage shelf 40 is installed between the first track 4A and the second track 4B. The first track 4A and the second track 4B are one-way tracks 4 and travel in different directions. For example, an overhead transport vehicle 6 traveling on the first track 4A travels in one direction in the X direction, while an overhead transport vehicle 6 traveling on the second track 4B travels in the other direction in the X direction. The height of the first track 4A and the height of the second track 4B are the same. The height of the track 4 corresponds, for example, to the height of the position where the overhead transport vehicle 6 touches the ground on the track 4.

The overhead transport vehicle 6 is an overhead unmanned transport vehicle. The overhead transport vehicle 6 travels along the track 4 and transports the item 10. The overhead transport vehicle 6 transfers the item 10 to the loading section 8 of the storage shelf 40. For example, an overhead transport vehicle 6 traveling on the first track 4A transfers the item 10 in the negative Y direction. The negative Y direction at this time is the loading direction when loading the item 10 onto the loading section 8. The loading direction corresponds to the direction in which the item 10 approaches the loading section 8 in a plan view, for example. Furthermore, an overhead transport vehicle 6 traveling on the second track 4B transfers the item 10 in the positive Y direction. The positive Y direction at this time is the loading direction. The loading direction of the item 10 is perpendicular to the X direction, which is the traveling direction of the overhead transport vehicle 6, for example in a horizontal plane. The number of overhead transport vehicles 6 is not particularly limited and may be multiple.

The overhead transport vehicle 6 has a travel unit 18 that travels along the track 4, and a power receiving and communication unit 20 that receives power from the track 4 via contactless power supply. The overhead transport vehicle 6 communicates with a controller (not shown) using the track 4's communication lines, etc. The overhead transport vehicle 6 has a main frame 23, a lateral delivery mechanism 24, a rotation mechanism 26, a lifting drive unit 28, a lifting platform 30, a holding unit 31, a main body cover 33, and a transport vehicle controller (control unit) 38.

The lateral delivery mechanism 24 moves the rotation mechanism 26, lifting drive unit 28, lifting platform 30, and holding unit 31 collectively in the Y direction. The lateral delivery mechanism 24 includes, for example, an upper member 24a attached to the main frame 23, a middle member 24b that can slide in and out in the Y direction along the upper member 24a, and a lower member 24c that can slide in and out in the Y direction along the middle member 24b. The rotation mechanism 26 is attached to the underside of the lower member 24c. The rotation mechanism 26 rotates the lifting drive unit 28, lifting platform 30, and holding unit 31 around a rotation axis that runs vertically. The lifting drive unit 28 raises and lowers the lifting platform 30 by winding or unwinding a suspension material such as a wire, rope, or belt.

The lifting platform 30 raises and lowers the holding unit 31. The holding unit 31 is provided on the lifting platform 30 and holds or releases the item 10 in a predetermined orientation. The holding unit 31 is also called a chuck. A pair of main body covers 33 are provided, for example, at the front and rear of the overhead transport vehicle 6 in the direction of travel. The transport vehicle controller 38 is disposed on the main body frame 23. The transport vehicle controller 38 is an electronic control unit composed of a CPU, ROM, RAM, etc., and controls the operation of each part of the overhead transport vehicle 6. Such an overhead transport vehicle 6 transfers the item 10 between the loading unit 8 of the storage shelf 40 by moving the lifting drive unit 28, etc. laterally using the lateral delivery mechanism 24 and raising and lowering the lifting platform 30.

The storage shelf 40 receives, supports, and stores the items 10 transferred from the overhead transport vehicle 6. The storage shelf 40 is a side track buffer (STB) located to the side of the track 4. The storage shelf 40 is suspended and supported by multiple shelf supports 9. The storage shelf 40 has a loading section 8 for storing the items 10. The items 10 are temporarily placed on the loading section 8. The items 10 are placed on the loading section 8 from the overhead transport vehicle 6 on the first track 4A and the overhead transport vehicle 6 on the second track 4B. The storage shelf 40 may have multiple loading sections 8 or only one loading section 8.

As shown in Figures 1, 3, and 4, the mounting section 8 has multiple protrusions 2 that can fit into the recesses 10h of the article 10, and a protrusion changing mechanism (protrusion changing device) 7 that changes the position of the multiple protrusions 2. The protrusions 2 are positioning pins that position the article 10 mounted on the mounting section 8. The protrusions 2 are, for example, kinematic pins. The protrusions 2 are columnar with their axial direction aligned vertically. The protrusions 2 protrude upward from the mounting surface 8a of the mounting section 8. The protrusions 2 include multiple first protrusions 21 and multiple second protrusions 22.

The first protrusions 21 are provided at positions corresponding to the multiple recesses 10h on the article 10 placed on the first track 4A from the ceiling transport vehicle 6A. The first protrusions 21 can be inserted into the multiple recesses 10h on the article 10 placed on the ceiling transport vehicle 6A until they hit the bottom of the recesses 10h. The first protrusions 21 are distributed over three points on the placement surface 8a that are not on a straight line. The multiple first protrusions 21 do not have 180-degree rotational symmetry around the vertical direction as the rotation axis. The multiple first protrusions 21 do not have 90-degree rotational symmetry around the vertical direction as the rotation axis.

The second protrusions 22 are provided at positions corresponding to the multiple recesses 10h on the article 10 placed on the second track 4B from the ceiling transport vehicle 6B. The second protrusions 22 are arranged between adjacent pairs of first protrusions 21. The second protrusions 22 can be inserted into the multiple recesses 10h on the article 10 placed on the ceiling transport vehicle 6B until they hit the bottom of the recesses 10h. The second protrusions 22 are arranged at three points that are not on a straight line on the placement surface 8a. The multiple second protrusions 22 do not have 180-degree rotational symmetry around the vertical direction as the rotation axis. The multiple second protrusions 22 do not have 90-degree rotational symmetry around the vertical direction as the rotation axis.

The convex portion changing mechanism 7 changes the positions of the multiple convex portions 2 so that the convex portions 2 fit into the recesses 10h, depending on the orientation of the item 10 placed on the mounting section 8. The convex portion changing mechanism 7 causes the convex portions 2 that are in contact with positions (flat portions) other than the recesses 10h on the bottom surface 10a of the item 10 to sink (move downward) due to the weight of the item 10. In the illustrated example, the convex portion changing mechanism 7 makes the height positions of the three first convex portions 21 higher than the height positions of the three second convex portions 22 (and makes the height positions of the three second convex portions 22 lower than the height positions of the three first convex portions 21) so that the three first convex portions 21 fit into the three recesses 10h, depending on the orientation of the item 10 placed on the mounting section 8. Alternatively, the convex portion changing mechanism 7 adjusts the height positions of the three second convex portions 22 higher than the height positions of the three first convex portions 21 (or adjusts the height positions of the three first convex portions 21 lower than the height positions of the three second convex portions 22) so that the three second convex portions 22 fit into the three recesses 10h, depending on the orientation of the article 10 placed on the placement section 8.

In the example shown in FIG. 4, the convex portion changing mechanism 7 supports the base end of the convex portion 2 at the bottom 8c of the mounting portion 8 via the spring 71 while causing the tip of the convex portion 2 to emerge above the mounting surface 8a through the hole 8b in the mounting surface 8a. As a result, the tip of the convex portion 2 protrudes upward from the mounting surface 8a while being biased upward by the spring 71, and is capable of moving vertically. The convex portion changing mechanism 7 connects the first convex portion 21 and the second convex portion 22 adjacent to the first convex portion 21 via the link mechanism 72. As a result, when either the first convex portion 21 or the second convex portion 22 is pushed down from above and sinks, the other of them is raised (moves upward) by the spring 71 and the link mechanism 72.

In this type of convex portion changing mechanism 7, for example, when the first convex portion 21 fits into the recess 10h, the first convex portion 21 abuts against the bottom surface of the recess 10h, and the first convex portion 21 positions the item 10. At this time, the second convex portion 22 comes into contact with the bottom surface 10a of the item 10 and is pushed downward by the weight of the item 10, causing it to sink. As a result, the link mechanism 72 pushes the first convex portion 21 upward in response to the sinking, causing it to float, and the first convex portion 21 is fixed to a certain extent in a state where it protrudes sufficiently and reliably from the placement surface 8a. Note that the configuration of the convex portion changing mechanism 7 is not limited to the example shown in the figures, and various configurations may be adopted.

Returning to Figure 1, the center-to-center distance L2 between the second track 4B and the transfer position of the loading section 8 is smaller than the center-to-center distance L1 between the first track 4A and the transfer position of the loading section 8. The center-to-center distance L1 between the first track 4A and the transfer position of the loading section 8 is larger than the center-to-center distance L2 between the second track 4B and the transfer position of the loading section 8. The transfer position is the position of the item 10 when the item 10 is positioned and placed on the loading section 8 (the convex portion 2 is fitted into the concave portion 10h).

The transport vehicle controller 38 of the overhead transport vehicle 6 traveling on the first track 4A controls the rotation mechanism 26 so that the orientation of the item 10 when unloading onto the loading section 8 (transferring the item 10 from the overhead transport vehicle 6 to the loading section 8) matches the predetermined orientation for the overhead transport vehicle 6 traveling on the second track 4B when loading the item 10 from the loading section 8 (transferring the item 10 from the loading section 8 to the overhead transport vehicle 6) after unloading.

For example, when unloading a load from the overhead transport vehicle 6A on the first track 4A onto the loading section 8, the transport vehicle controller 38 rotates the holding section 31 180 degrees using the rotation mechanism 26, taking into account the subsequent loading by the overhead transport vehicle 6B on the second track 4B, and rotates the orientation of the item 10 180 degrees in the horizontal plane.

Specifically, with the ceiling transport vehicle 6A in the state shown in FIG. 5(a), the transport vehicle controller 38 first moves the lifting drive unit 28 laterally using the lateral delivery mechanism 24. This moves the item 10 laterally, as shown in FIG. 5(b). The item 10 is positioned at this time so that the rotational trajectory of the item 10 does not interfere with the ceiling transport vehicle 6B traveling on the second track 4B. The transport vehicle controller 38 rotates the holding unit 31 180 degrees using the rotation mechanism 26. This rotates the orientation of the item 10 180 degrees without interfering with the ceiling transport vehicle 6B traveling on the second track 4B, as shown in FIG. 5(c), FIG. 6(a), and FIG. 6(b) in that order.

The transport vehicle controller 38 then causes the lateral delivery mechanism 24 to move the lifting drive unit 28 laterally until the item 10 is positioned above the transfer position on the platform 8. As a result, as shown in FIG. 6(c), the item 10 is moved laterally until it is positioned directly above the transfer position on the platform 8. The lifting drive unit 28 then lowers the holding unit 31. As a result, the item 10 is placed from the ceiling transport vehicle 6A onto the platform 8.

Furthermore, for example, when unloading a load from the overhead transport vehicle 6B on the second track 4B onto the loading section 8, the transport vehicle controller 38 rotates the holding section 31 180 degrees using the rotation mechanism 26, taking into account the subsequent loading by the overhead transport vehicle 6A on the first track 4A, and rotates the orientation of the item 10 180 degrees in the horizontal plane.

Specifically, in the ceiling transport vehicle 6B in the state shown in FIG. 7(a), the transport vehicle controller 38 first causes the lateral delivery mechanism 24 to move the lifting drive unit 28 laterally until the article 10 is positioned above the transfer position of the placement unit 8. As a result, the article 10 is moved laterally until it is positioned directly above the transfer position of the placement unit 8, as shown in FIG. 7(b). The transport vehicle controller 38 then causes the rotation mechanism 26 to rotate the holding unit 31 180 degrees. As a result, the orientation of the article 10 is rotated 180 degrees, as shown in FIGS. 7(c), 8(a), and 8(b) in that order. The lifting drive unit 28 then lowers the holding unit 31. As a result, the article 10 is placed from the ceiling transport vehicle 6B onto the placement unit 8. At this time, the first track 4A and the placement unit 8 are sufficiently separated, so the article 10 can be rotated on the placement unit 8 without coming into contact with the ceiling transport vehicle 6A traveling on the first track 4A.

As described above, in the ceiling transport vehicle system 1, the article 10 can be placed on the placement section 8 simply by changing the positions of the multiple protrusions 2 without rotating the placement section 8, regardless of the direction in which the article 10 faces relative to the placement section 8. This improves the degree of freedom in the placement direction of the article 10 on the placement section 8 without requiring any special space. For example, regardless of whether the placement direction of the article 10 on the placement section 8 is the negative or positive Y direction, the article 10 can be positioned and placed on the placement section 8 using the protrusions 2 without requiring a separate large mechanism. As a result, the placement section 8 can be shared between multiple tracks 4 traveling in different directions.

In the ceiling transport vehicle system 1, the transport vehicle controller 38 controls the rotation mechanism 26 so that the orientation of the item 10 when unloading onto the loading section 8 matches the predetermined orientation of the item 10 held by the holding section 31 when loading from the loading section 8 after unloading. In this case, the item 10 can be loaded onto the loading section 8 in an orientation appropriate for the next loading, thereby shortening the dwell time for holding the item 10 by the holding section 31 when loading the next loading.

In the ceiling transport vehicle system 1, the convexity changing mechanism 7 causes the convexity 2 that comes into contact with a position on the bottom surface 10a of the item 10 other than the concave portion 10h to sink due to the weight of the item 10. In this case, the position of the convexity 2 can be changed using a simple mechanism.

In the overhead transport vehicle system 1, the height of the first track 4A and the height of the second track 4B are the same, and the traveling direction of the first track 4A and the traveling direction of the second track 4B are opposite. In this case, it is possible to transfer items 10 via the loading section 8 between the first track 4A and the second track 4B, which are at the same height and traveling in opposite directions.

In the overhead transport vehicle system 1, the center-to-center distance L2 between the second track 4B and the transfer position of the placement unit 8 is smaller than the center-to-center distance L1 between the first track 4A and the transfer position of the placement unit 8. Because the center-to-center distance L2 is smaller than the center-to-center distance L1, when placing an item 10 from the overhead transport vehicle 6A on the first track 4A onto the placement unit 8, if the holding unit 31 is rotated to rotate the item 10 at the transfer position of the placement unit 8, the rotating item 10 may be prone to interference with the overhead transport vehicle 6B traveling on the second track 4B. In this regard, in the overhead transport vehicle system 1, such interference can be avoided by rotating the holding unit 31 to a position where the rotational trajectory of the item 10 does not interfere with the overhead transport vehicle 6B traveling on the second track 4B, and then moving the lifting drive unit 28 laterally again until the item 10 is positioned at the transfer position.

In this embodiment, when the rotation mechanism 26 is used to change the orientation of the item 10 and place the item 10 on the placement section 8, there is no concern about interference with the main body cover 33 (front frame and rear frame), there is no need to change the external shape of the overhead transport vehicle 6, and the overhead transport vehicle 6 can easily run on the existing track 4.

It is also possible to change the orientation of the item 10 by rotating it using the rotation mechanism 26 when the item 10 is lowered by the lifting drive unit 28 and positioned outside the main body cover 33. However, in this case, the reaction force of the rotation is received by the lifting material (wire, rope, belt, etc.) of the lifting drive unit 28, making it difficult to stabilize the position. In this regard, in this embodiment, the rotation mechanism 26 rotates the item 10 before the lifting drive unit 28 lowers the item 10. This is effective in stabilizing the position.

Although the embodiments have been described above, one aspect of the present invention is not limited to the above embodiments. Various modifications are possible without departing from the spirit of one aspect of the invention.

The above embodiment includes a convex portion changing mechanism 7 as the convex portion changing device, but this is not limited to this. For example, the above embodiment may include a convex portion changing device 107 shown in Figure 9 instead of the convex portion changing mechanism 7.

The convex portion changing device 107 is a mechanism for horizontally rotating (rotating within a horizontal plane) the three convex portions 2. Specifically, the convex portion changing device 107 includes a rotating table 171, a shaft 172, and a motor 173. The rotating table 171 is a circular plate-shaped member. The rotating table 171 is inserted into a hole 8x formed in the mounting surface 8a so as to be rotatable around its central axis. The shaft 172 is a columnar body that forms the rotation axis of the rotating table 171 and is coaxial with the rotating table 171 and connected to the underside of the rotating table 171. The motor 173 is a driving source that applies driving force to rotate the rotating table 171. A drive gear 173a provided on the output shaft of the motor 173 meshes with a driven gear 172a provided on the shaft 172. The operation of the motor 173 is controlled by commands from the transport vehicle controller 38 of the ceiling transport vehicle 6.

In this type of convex portion changing device 107, the operation of the motor 173 is controlled by the transport vehicle controller 38 so that the rotational position of the turntable changes depending on the orientation of the item 10 placed on the placement section 8. As a result, the turntable 171 is rotated appropriately, and the positions of the multiple convex portions 2 are changed in the rotational direction so that they fit into the recesses 10h of the item 10. For example, the convex portion changing device 107 rotates the turntable 171 0 degrees (i.e., does not rotate) or 180 degrees depending on the orientation of the item 10 placed on the placement section 8. Using this type of convex portion changing device 107, it is possible to specifically change the position of the convex portions 2.

In the above embodiment, the height of the first track 4A and the height of the second track 4B may be different. In this case, it is possible to transfer the item 10 between the first track 4A and the second track 4B, which are at different heights, via the loading section 8. Furthermore, when the heights of the tracks 4 are different, the tracks 4 may completely overlap in a planar view. Furthermore, the tracks 4 may be parallel or intersect in a planar view.

The configurations of the above embodiments or modifications can be applied to the configurations of other embodiments or modifications. Some of the configurations of the above embodiments or modifications can be omitted as appropriate without departing from the spirit of one aspect of the present invention.

1...Ceiling transport vehicle system, 2...Protrusion, 4...Track, 4A...First track, 4B...Second track, 6...Ceiling transport vehicle, 7...Protrusion change mechanism (protrusion change device), 8...Placement section, 10...Article, 10a...Bottom surface, 10h...Recess, 21...First protrusion, 22...Second protrusion, 24...Side-out mechanism, 26...Rotation mechanism, 28...Lifting drive section, 31...Holding section, 38...Transport vehicle controller (control section). L1, L2...Center distance, 107...Protrusion change device.

Claims (5)

a track including a first track and a second track having different running directions;
an overhead transport vehicle having a holding unit that holds an article in a predetermined orientation and that travels along the track;
a placement unit on which the article is placed from the ceiling transport vehicle on the first track and the ceiling transport vehicle on the second track,
a plurality of recesses are formed on the bottom surface of the article so that the positional relationship with the placement section changes depending on the orientation of the article;
The placement unit is
a plurality of protrusions that can be fitted into the recesses;
a convex portion changing device that changes the position of at least one of the plurality of convex portions so that the convex portion fits into the concave portion according to the orientation of the article placed on the placement portion ,
The placement unit is provided with the convex portions at positions corresponding to the plurality of concave portions of the article when the article is placed from the ceiling transport vehicle on the first track, and at positions corresponding to the plurality of concave portions of the article when the article is placed from the ceiling transport vehicle on the second track,
The convex portion changing device is a ceiling transport vehicle system that causes the convex portion that comes into contact with a position on the bottom surface of the item that is not the concave portion to sink due to the weight of the item . the ceiling transport vehicle has a rotation mechanism that rotates the holding unit around a rotation axis along a vertical direction, and a control unit that controls the operation of the ceiling transport vehicle,
The ceiling transport vehicle system of claim 1, wherein the control unit of the ceiling transport vehicle traveling on the first track controls the rotation mechanism so that the orientation of the item when unloaded onto the storage section matches the predetermined orientation for the ceiling transport vehicle traveling on the second track and loading the item from the storage section after unloading. The height of the first track and the height of the second track are the same,
The overhead transport vehicle system according to claim 1 or 2, wherein the first track and the second track travel in opposite directions. The ceiling transport vehicle system described in claim 1 or 2, wherein the height of the first track and the height of the second track are different. a track including a first track and a second track having different running directions;
an overhead transport vehicle having a holding unit that holds an article in a predetermined orientation and that travels along the track;
a placement unit on which the article is placed from the ceiling transport vehicle on the first track and the ceiling transport vehicle on the second track,
a plurality of recesses are formed on the bottom surface of the article so that the positional relationship with the placement section changes depending on the orientation of the article;
The placement unit is
a plurality of protrusions that can be fitted into the recesses;
a convex portion changing device that changes the position of at least one of the plurality of convex portions so that the convex portion fits into the concave portion according to the orientation of the article placed on the placement portion,
The ceiling transport vehicle has a main body, a rotation mechanism that rotates the holding unit around a rotation axis along a vertical direction, a lifting drive unit that raises and lowers the holding unit, a lateral movement mechanism that moves the lifting drive unit laterally from the main body, and a control unit that controls the operation of the ceiling transport vehicle,
The ceiling transport vehicle has a pair of body covers provided at the front and rear of the ceiling transport vehicle in the traveling direction,
In a plan view, when the article is positioned between the pair of body covers, a rotation trajectory of the article when the holding portion holding the article is rotated by the rotation mechanism interferes with the pair of body covers,
a center-to-center distance between the second track and the transfer position of the placement unit is smaller than a center-to-center distance between the first track and the transfer position of the placement unit;
In a plan view, when the article located directly above the transfer position of the placement section is rotated by the rotation mechanism, the rotation trajectory overlaps with the travel trajectory of the overhead transport vehicle traveling on the second track, but does not overlap with the travel trajectory of the overhead transport vehicle traveling on the first track;
The control unit
When the item is placed from the ceiling transport vehicle on the first track onto the storage section, the lifting drive unit is moved laterally by the lateral ejection mechanism to position it closer to the first track than the transfer position of the storage section and at a position where the rotation trajectory of the item does not interfere with the pair of main body covers of the ceiling transport vehicle on the first track in a planar view, the holding section is rotated by the rotation mechanism, and then the lifting drive unit is moved laterally by the lateral ejection mechanism until the item is positioned directly above the transfer position, and the holding section is lowered by the lifting drive unit .