Overhead transport vehicle

Abstract

An overhead transport vehicle includes a holding unit configured to be able to be raised and lower and to hold an article, a raising and lowering drive section that raises and lowers the holding unit, a lateral transfer mechanism that moves the raising and lowering drive section laterally with respect to a main body section, a monitoring sensor that is provided to the raising and lowering drive section, monitors an area below the raising and lowering drive section, and is able to change a monitoring range, and a controller that changes the monitoring range of the monitoring sensor in accordance with information related to a tilt of the raising and lowering drive section with respect to a horizontal plane.

Description

Technical Field

[0001] One aspect of the present invention relates to an elevated transport vehicle. Background Technology

[0002] As for the technology related to overhead conveyor vehicles, for example, there is a conveyor vehicle described in Patent Document 1. The conveyor vehicle described in Patent Document 1 includes: a main body; a lifting platform (holding unit) having a holding part for holding items; a lifting drive unit (lifting drive unit) that lifts and lowers the lifting platform by pulling out and winding up the suspension member; a swing detection sensor (monitoring sensor) provided in the lifting drive unit that irradiates a laser downwards and detects the reflected light; and a lateral extension mechanism (lateral transfer mechanism) that causes the lifting drive unit to protrude laterally relative to the main body in a cantilevered support state.

[0003] Patent Document 1: International Publication No. 2017 / 199593

[0004] However, in overhead conveyor systems, when the lifting drive unit is moved laterally relative to the main body via a lateral transfer mechanism (e.g., during lateral transfer), the lifting drive unit may tilt relative to the horizontal direction due to factors such as deflection of the lateral transfer mechanism's moving shaft. If the lifting drive unit tilts, the monitoring sensor may be unable to accurately monitor the area below the lifting drive unit due to this tilt. In this regard, while the aforementioned techniques aim to reduce the impact of the lifting drive unit's tilt by using actuators to mechanically (physically) change the posture of the monitoring sensor, there is still room for improvement in accurately monitoring the area below the lifting drive unit. Summary of the Invention

[0005] Therefore, one objective of the present invention is to provide an overhead conveyor that can accurately monitor the area below the lifting drive unit even when the lifting drive unit has been moved to the side.

[0006] An aspect of the present invention relates to an elevated transport vehicle comprising: a holding unit configured to be raised and lowered and to hold an item; a lifting drive unit that raises and lowers the holding unit; a lateral transfer mechanism that moves the lifting drive unit laterally relative to a main body; a monitoring sensor disposed on the lifting drive unit, monitoring below the lifting drive unit and capable of changing the monitoring range; and a controller that changes the monitoring range of the monitoring sensor based on information related to the tilt of the lifting drive unit relative to a horizontal plane.

[0007] In this overhead conveyor, even when the lifting drive unit is moved laterally relative to the main body via the lateral transfer mechanism, and the lifting drive unit tilts relative to the horizontal plane (hereinafter referred to simply as "tilt"), the controller can adjust the monitoring range of the monitoring sensor according to the tilt to always monitor, for example, the same range as before the tilt occurred. That is, even when the lifting drive unit is moved laterally, the area below the lifting drive unit can be accurately monitored.

[0008] In one aspect of the overhead conveyor according to the present invention, the controller may store the monitoring range of the monitoring sensor, i.e., the first to third monitoring ranges, respectively, corresponding to the lifting and lowering modes of the holding unit, i.e., the first to third modes. When the lifting and lowering mode of the holding unit is the first mode, the monitoring range is changed to the first monitoring range; when the lifting and lowering mode of the holding unit is the second mode, the monitoring range is changed to the second monitoring range; and when the lifting and lowering mode of the holding unit is the third mode, the monitoring range is changed to the third monitoring range. Thus, when the lifting and lowering mode of the holding unit is any of the first to third modes, the monitoring range of the monitoring sensor can be changed to any of the first to third monitoring ranges corresponding to that mode.

[0009] In the overhead conveyor according to one aspect of the present invention, the first mode is a mode in which the holding unit is raised and lowered directly below the main body; the second mode is a mode in which the holding unit without holding an item is raised and lowered while the lifting drive unit is moved laterally relative to the main body; and the third mode is a mode in which the holding unit with an item is raised and lowered while the lifting drive unit is moved laterally relative to the main body. Therefore, the monitoring range of the monitoring sensor can be varied depending on the specific mode in which the holding unit is raised and lowered.

[0010] In the overhead conveyor according to one aspect of the present invention, the first monitoring range may extend from the monitoring sensor in the reference posture toward a first direction along the vertical direction; the second monitoring range may extend from the monitoring sensor in the reference posture toward a second direction, wherein the second direction is a direction that tilts the first direction by a first angle; and the third monitoring range may extend from the monitoring sensor in the reference posture toward a third direction, wherein the third direction is a direction that tilts the first direction by a second angle larger than the first angle. In this case, the lifting drive unit is more likely to tilt in the second mode than in the first mode when the holding unit is raised and lowered, and the lifting drive unit is more likely to tilt in the third mode than in the second mode when the holding unit is raised and lowered. Based on this understanding, the first to third monitoring ranges can be set.

[0011] In one aspect of the overhead conveyor according to the present invention, a reflector may be provided in the holding unit, a monitoring sensor may be used to illuminate light toward the reflector, and the reflected light may be detected when the light is reflected by the reflector. In this case, the monitoring sensor can monitor the area below the lifting drive unit (such as the swing of the holding unit) by, for example, whether or not reflected light is detected.

[0012] In the overhead conveyor according to one aspect of the present invention, the monitoring sensor may allow the orientation of the monitoring range to be changed at least along the first horizontal direction. Thus, even if a tilt occurs in the lifting drive unit where one side of the first horizontal direction rises relative to the other, the orientation of the monitoring range can be changed by the monitoring sensor in accordance with this tilt, accurately monitoring the area below the lifting drive unit.

[0013] In the overhead conveyor according to one aspect of the present invention, the first horizontal direction may correspond to the direction in which the lifting drive unit can be moved by the lateral transfer mechanism. In this case, if the moving shaft of the lateral transfer mechanism deflects when the lifting drive unit has been moved laterally by the lateral transfer mechanism, the orientation of the monitoring range is prone to deviate in the first horizontal direction. Therefore, in this case, a monitoring sensor that allows the orientation of the monitoring range to be changed along the first horizontal direction is particularly effective.

[0014] Alternatively, the elevated transport vehicle according to one aspect of the present invention may include an adjustment mechanism that adjusts the positional relationship between the monitoring sensor and the lifting drive unit by changing the orientation of the monitoring range of the monitoring sensor in a second horizontal direction perpendicular to the first horizontal direction. In this case, the orientation of the monitoring range of the monitoring sensor in the second horizontal direction can be adjusted by the adjustment mechanism.

[0015] Alternatively, the elevated transport vehicle according to one aspect of the present invention may be equipped with a tilt detection sensor. This tilt detection sensor detects the tilt of the lifting drive unit relative to the horizontal plane, and the controller adjusts the monitoring range of the monitoring sensor based on the detection result of the tilt detection sensor. In this case, by detecting the tilt of the lifting drive unit using the tilt detection sensor, and by adjusting the monitoring range of the monitoring sensor based on the tilt using the controller, it is possible to monitor, for example, the same area as before the tilt occurred. Furthermore, it is possible to accurately monitor the area below the lifting drive unit.

[0016] According to one aspect of the invention, an overhead conveyor can be provided that can accurately monitor the area below the lifting drive unit even when the lifting drive unit has been moved to the side. Attached Figure Description

[0017] Figure 1This is a side view of an elevated transport vehicle according to one embodiment.

[0018] Figure 2 It means Figure 1 The main view of the transfer mode directly below the overhead conveyor.

[0019] Figure 3 It means Figure 1 A top view of the reflector.

[0020] Figure 4 (a) is a schematic front view representing the first monitoring range. Figure 4 (b) is a schematic front view representing the second monitoring range. Figure 4 (c) is a schematic front view representing the third monitoring range. Figure 4 (d) is a schematic front view representing the fourth monitoring range. Figure 4 (e) is a schematic front view representing the fifth monitoring range.

[0021] Figure 5 (a) is a front view that explains the settings of the first monitoring range. Figure 5 (b) is for Figure 5 The main view that follows (a). Figure 5 (c) is for Figure 5 The main view that follows (b).

[0022] Figure 6 It means Figure 1 The front view of the lateral transfer mode during loading of the overhead conveyor truck.

[0023] Figure 7 It means Figure 1 The front view of the lateral transfer mode during unloading of the overhead conveyor truck. Detailed Implementation

[0024] Hereinafter, an embodiment will be described in detail with reference to the accompanying drawings. Furthermore, in the description of the drawings, the same reference numerals are used to label the same elements, and repeated descriptions are omitted.

[0025] like Figure 1 As shown, the overhead conveyor 1 in this embodiment travels along a track 20 laid near the ceiling of the cleanroom where semiconductor devices are manufactured. The track 20 forms the travel path of the overhead conveyor 1. The overhead conveyor 1 transports FOUP (Front Opening Unified Pod) 200 containing multiple semiconductor wafers and transfers FOUP 200 to loading ports 300 provided in processing apparatuses that perform various processing on semiconductor wafers.

[0026] The overhead conveyor 1 comprises a frame unit (main body) 2, a travel unit 3, a transverse unit (transverse transfer mechanism) 4, a rotation unit 5, a lifting drive unit (lifting drive unit) 6, a holding unit 7, and a conveyor controller (controller) 8. The frame unit 2 has a central frame 15, a front frame 16, and a rear frame 17. The front frame 16 extends downward from the front end of the central frame 15 (the front end in the travel direction of the overhead conveyor 1). The rear frame 17 extends downward from the rear end of the central frame 15 (the rear end in the travel direction of the overhead conveyor 1).

[0027] The traveling unit 3 is positioned above the central frame 15. The traveling unit 3 travels along the track 20, for example, by receiving power non-contactly from a high-frequency current line laid along the track 20. The lateral unit 4 is positioned below the central frame 15. The lateral unit 4 causes the rotating unit 5, the lifting drive unit 6, and the holding unit 7 to move laterally (laterally, in the direction of travel of the overhead conveyor 1) relative to the frame unit 2. The rotating unit 5 is positioned below the lateral unit 4. The rotating unit 5 causes the lifting drive unit 6 and the holding unit 7 to rotate in the horizontal plane.

[0028] The lifting drive unit 6 is disposed below the rotating unit 5. The lifting drive unit 6 raises and lowers the holding unit 7 by pulling out and winding multiple belts (suspension members) B connected to the holding unit 7. The holding unit 7 is disposed below the lifting drive unit 6. The holding unit 7 is configured to be raised and lowered by the lifting drive unit 6. The holding unit 7 has a pair of grippers 12 that can be opened and closed in the horizontal direction. The holding unit 7 holds the flange 201 of the FOUP 200 by the pair of grippers 12.

[0029] The transport vehicle controller 8 is located on the central frame 15. The transport vehicle controller 8 is an electronic control unit composed of a CPU (Central Processing Unit), ROM (Read Only Memory), and RAM (Random Access Memory). The transport vehicle controller 8 controls various parts of the overhead transport vehicle 1. The transport vehicle controller 8 can also be composed of multiple electronic control units. Furthermore, the transport vehicle controller 8 can also be located on the front frame 16, etc.

[0030] As an example, the overhead conveyor 1 configured as described above operates as follows. When transferring FOUP 200 from loading port 300 to overhead conveyor 1, the overhead conveyor 1, without holding FOUP 200, stops at a predetermined position above loading port 300. When the position of holding unit 7, which is lowered at the stop position, deviates from the predetermined position relative to loading port 300 (where FOUP 200 is placed), the horizontal position and horizontal angle of holding unit 7 are adjusted by driving lateral unit 4 and rotation unit 5. Next, lifting drive unit 6 lowers holding unit 7, which holds the flange 201 of FOUP 200 placed in loading port 300. Next, lifting drive unit 6 raises holding unit 7 to the rising end, positioning FOUP 200 between front frame 16 and rear frame 17. Then, overhead conveyor 1, holding FOUP 200, begins to move.

[0031] On the other hand, when transferring FOUP 200 from the overhead conveyor 1 to the loading port 300, the overhead conveyor 1, holding FOUP 200, stops at a predetermined position above the loading port 300. If the position of the holding unit 7 (FOUP 200) descending from the stopped position deviates from the predetermined position relative to the loading port 300, the horizontal position and horizontal angle of the holding unit are adjusted by driving the lateral unit 4 and the rotation unit 5. Next, the lifting drive unit 6 lowers the holding unit 7, placing FOUP 200 on the loading port 300, and the holding unit 7 releases the flange 201 holding FOUP 200. Next, the lifting drive unit 6 raises the holding unit 7 to the rising end. Then, the overhead conveyor 1, no longer holding FOUP 200, begins to move.

[0032] like Figure 1 as well as Figure 2 As shown, the overhead conveyor 1 includes a monitoring sensor 10, a reflector 11, and a tilt detection sensor 13. The monitoring sensor 10 is located on the lifting drive unit 6. The monitoring sensor 10 monitors the area below the lifting drive unit 6. The monitoring sensor 10 is a sensor capable of changing the monitoring range (the range from which the detection result is valid, etc.) A. While not particularly limited, the monitoring sensor 10 can be, for example, a laser rangefinder; if the monitoring range A can be set by an input, the monitoring range A can be changed by changing that input. The monitoring sensor 10 irradiates a laser beam towards the reflector 11 below and detects the reflected light when the laser beam is reflected by the reflector 11. The monitoring sensor 10 is connected to the conveyor controller 8.

[0033] A reflector 11 is disposed on the holding unit 7. As an example, the reflector 11 is disposed in the upper center of the holding unit 7. The reflector 11 is configured with its reflective surface facing upward, so that laser light from above is reflected upward. The reflector 11 is disposed directly below the monitoring sensor 10 when the lifting drive unit 6 is in a horizontal state. There is no particular limitation on the reflector 11, and various reflectors can be used.

[0034] The tilt detection sensor 13 detects the tilt of the lifting drive unit 6 relative to the horizontal plane. The tilt detection sensor 13 is disposed on the lifting drive unit 6. The tilt detection sensor 13 can also be, for example, a triaxial sensor or an accelerometer. When the tilt of the lifting drive unit 6 relative to the horizontal plane is 0°, the lifting drive unit 6 is in a horizontal state. For example, the lifting drive unit 6 is in a horizontal state when its long side is along the horizontal plane. Furthermore, the lifting drive unit 6 is in a horizontal state when the lateral direction of the movement of the lifting drive unit 6 by the lateral unit 4 is horizontal.

[0035] like Figure 3 as well as Figure 4 As shown in (a), the monitoring sensor 10 moves the light spot P along one horizontal direction, namely the Y direction (the first horizontal direction), to perform a region scan of the laser L. The region scan range SL is a predetermined range set in advance and exists on the YZ plane with the vertical direction as the Z direction. Figure 4 (a)~ Figure 4 As shown in (e), the monitoring sensor 10 can change the orientation of the monitoring range A in the Y direction. The Y direction in which the monitoring sensor 10 can change the orientation of the monitoring range A corresponds to the direction in which the lifting drive unit 6 can be moved by the lateral unit 4.

[0036] The transport vehicle controller 8 changes the monitoring range A of the monitoring sensor 10 based on information related to the tilt of the lifting drive unit 6 relative to the horizontal plane (hereinafter, also referred to as "tilt information"). The transport vehicle controller 8 changes the orientation of the monitoring range A in the direction along the Y direction. Here, the transport vehicle controller 8 can change the monitoring range A of the monitoring sensor 10 to any one of the 1st to 5th monitoring ranges A0, A11, A12, A21, and A22. The tilt information includes information on which of the 1st to 3rd modes, described later, is used to raise and lower the holding unit 7. The tilt information includes the detection result of the tilt detection sensor 13.

[0037] The first monitoring range A0 is the range within the monitoring sensor 10 in the reference posture, extending towards the first direction along the Z-direction (vertical direction). Furthermore, the first monitoring range A0 is the reference monitoring range. The monitoring sensor 10 in the reference posture is the posture of the lifting drive unit 6, on which the monitoring sensor 10 is installed, when its tilt relative to the horizontal plane is 0° (hereinafter, the same). The second monitoring range A11 is the range within the monitoring sensor in the reference posture, extending towards the second direction, which is the direction in which the first direction is tilted by a first angle in the YZ plane. The first angle is, for example, 2° to 3°.

[0038] The third monitoring range A12 is the range in the monitoring sensor of the reference posture facing a third direction, which is the direction in which the first direction is tilted by a second angle in the YZ plane. The second angle is greater than the first angle. The second angle is, for example, 4° to 5°. The fourth monitoring range A21 is the range in the monitoring sensor of the reference posture facing a fourth direction, which is the direction in which the first direction is tilted by a first angle to the opposite side of the second monitoring range A11. The fifth monitoring range A22 is the range in the monitoring sensor of the reference posture facing a fifth direction, which is the direction in which the first direction is tilted by a second angle larger than the first angle to the opposite side of the third monitoring range A12.

[0039] The monitoring ranges A0, A11, A12, A21, and A22, from 1 to 5, can be automatically set by the transport vehicle controller 8, for example, as follows. That is, as... Figure 5 As shown in (a), a region scan of the reflector 11 along the Y direction is performed by the monitoring sensor 10 with a reference posture. Based on the detection results of the monitoring sensor 10, the position of one end of the reflector 11 in the Y direction (the angle of the laser L captured at one end) is determined. Furthermore, as... Figure 5 As shown in (b), the position of the other end of the reflector 11 in the Y direction (the angle of the laser L captured at the other end) is determined based on the detection result of the monitoring sensor 10.

[0040] Next, based on the positions of one end and the other end of the reflector 11 in the Y direction, the position of the center of the reflector 11 (the angle of the laser L at the center of capture) is determined. For example... Figure 5As shown in (c), a range with a constant width based on the center position is defined as the first monitoring range A0. A range tilted by a first angle to one side of the Y direction is defined as the second monitoring range A11. A range tilted by a second angle to one side of the Y direction is defined as the third monitoring range A12. A range tilted by a first angle to the other side of the Y direction is defined as the fourth monitoring range A21. A range tilted by a second angle to the other side of the Y direction is defined as the fifth monitoring range A22. The first and second angles can also be predetermined, for example, through prior teaching.

[0041] like Figure 1 As shown, the transport vehicle controller 8 stores the first to third monitoring ranges A0, A11, and A12 of the monitoring sensor 10 respectively corresponding to the modes for raising and lowering the holding unit 7 (hereinafter also referred to as "raising and lowering modes"), i.e., the first to third modes. The first mode is the mode for raising and lowering the holding unit 7 directly below the central frame 15 of the frame unit 2 (see reference). Figure 2 The first mode is the direct downward transfer mode. The first mode is the lifting mode when the tilt of the lifting drive unit 6 is 0° to "small".

[0042] The second mode is a mode in which the lifting drive unit 6 is moved laterally relative to the frame unit 2 by the lateral unit 4, and the holding unit 7, which does not hold FOUP200, is raised and lowered (see reference). Figure 6 The second mode is the lateral transfer mode during loading. The second mode is the lifting mode when the tilt of the lifting drive unit 6 is "neutral". The third mode is the mode in which the holding unit 7 holding FOUP200 is raised and lowered when the lifting drive unit 6 is moved laterally relative to the frame unit 2 by the lateral unit 4 (see reference). Figure 7 The third mode is the lateral transfer mode during unloading. The third mode is the lifting mode when the tilt of the lifting drive unit 6 is "large".

[0043] The first monitoring range A0 is the range set when the lifting mode is in the first mode, which is the range viewed from the front towards the vertical direction (see reference). Figure 2 The second monitoring range A11 is the range set to be viewed from the front and directed downwards in the vertical direction when the lifting mode is in the second mode (see reference). Figure 6 The third monitoring range A12 is the range set to be viewed from the front and directed downwards in the vertical direction when the lifting mode is in the third mode (see reference). Figure 7 ).

[0044] When the lifting mode is in mode 1, the transport vehicle controller 8 changes the monitoring range A to the first monitoring range A0. When the lifting mode is in mode 2, the transport vehicle controller 8 changes the monitoring range A to the second monitoring range A11. When the lifting mode is in mode 3, the transport vehicle controller 8 changes the monitoring range A to the third monitoring range A12. The transport vehicle controller 8 changes the monitoring range of the monitoring sensor 10 based on the detection result of the tilt detection sensor 13. In addition, the lifting mode can be determined in the transport vehicle controller 8 based on, for example, the driving status of various devices of the overhead transport vehicle 1, the detection results of various sensors, and the transport commands received from the upper controller.

[0045] The overhead conveyor 1 is equipped with an adjustment mechanism that allows for adjusting the positional relationship between the monitoring sensor 10 and the lifting drive unit 6 in a manner that enables physical adjustment of the orientation of the monitoring range A of the monitoring sensor 10 in the X direction (second horizontal direction), which is perpendicular to the Y direction. For example, the adjustment mechanism includes an elongated hole in the X direction for inserting bolts that secure the monitoring sensor 10 to the lifting drive unit 6. In this case, by adjusting the position of the monitoring sensor 10 secured to the lifting drive unit 6 in the X direction using the elongated hole, the orientation of the monitoring range A of the monitoring sensor 10 in the X direction can be adjusted. Furthermore, the adjustment mechanism is not particularly limited; various known structures can be used, or the adjustment mechanism may be omitted depending on the situation. On the other hand, the physical positional relationship between the monitoring sensor 10 and the lifting drive unit 6 in the Y direction may be configured to be non-adjustable.

[0046] In such an elevated transport vehicle 1, for example... Figure 2 As shown, in the first mode, where the lifting mode is the direct downward transfer mode, the monitoring range A becomes the first monitoring range A0 via the transport vehicle controller 8, and the holding unit 7 is raised and lowered via the lifting drive unit 6. Furthermore, the monitoring range A is changed by the transport vehicle controller 8 based on the detection result of the tilt detection sensor 13. As a result, when the holding unit 7 does not sway, the monitoring sensor 10 reliably receives the reflected light from the reflector 11, thereby detecting that no sway has occurred. On the other hand, when the holding unit 7 sways, for example, the laser L from the monitoring sensor 10 does not project onto (does not touch) the reflector 11, and the monitoring sensor 10 does not receive the reflected light from the reflector 11. Therefore, sway can be detected.

[0047] In the elevated transport vehicle 1, for example... Figure 6As shown, in the second mode of the lateral transfer mode during loading, the monitoring range A is changed to the second monitoring range A11 by the transport vehicle controller 8, and the holding unit 7, which does not hold the FOUP 200, is raised and lowered by the lifting drive unit 6. At this time, the monitoring range A is changed by the transport vehicle controller 8 according to the detection result of the tilt detection sensor 13. As a result, when the holding unit 7 does not swing, the monitoring sensor 10 reliably receives the reflected light from the reflector 11, thereby detecting that no swing has occurred. On the other hand, when the holding unit 7 swings, for example, the laser L from the monitoring sensor 10 is not projected onto the reflector 11, and the monitoring sensor 10 does not receive the reflected light from the reflector 11. Thus, swing can be detected.

[0048] In the elevated transport vehicle 1, for example... Figure 7 As shown, in the third mode of the lateral transfer mode during unloading, the monitoring range A is changed to the third monitoring range A21 by the transport vehicle controller 8, and the holding unit 7 holding the FOUP200 is raised and lowered by the lifting drive unit 6. At this time, the monitoring range A is changed by the transport vehicle controller 8 according to the detection result of the tilt detection sensor 13. As a result, when the holding unit 7 does not swing, the monitoring sensor 10 reliably receives the reflected light from the reflector 11, thereby detecting that no swing has occurred. On the other hand, when the holding unit 7 swings, for example, the laser L from the monitoring sensor 10 is not projected onto the reflector 11, and the monitoring sensor 10 does not receive the reflected light from the reflector 11. Thus, swing can be detected.

[0049] According to the above, when the lifting drive unit 6 is moved laterally by the lateral unit 4, even if the lifting drive unit 6 tilts, the monitoring range A of the monitoring sensor 10 can be adjusted according to the tilt by the transport vehicle controller 8 to monitor, for example, the same range as before the tilt occurred. That is, even when the lifting drive unit 6 is moved laterally, the area below the lifting drive unit 6 can be monitored accurately. Even when the lifting drive unit 6 tilts during horizontal transfer, the swing detection of the holding unit 7 can be performed normally.

[0050] In the elevated transport vehicle 1, the transport vehicle controller 8 stores the first to third monitoring ranges A0, A11, and A12 respectively, corresponding to the first to third lifting modes. When the lifting mode is mode 1, the transport vehicle controller 8 changes the monitoring range A to the first monitoring range A0; when the lifting mode is mode 2, it changes the monitoring range A to the second monitoring range A12; and when the lifting mode is mode 3, it changes the monitoring range A to the third monitoring range A12. Therefore, when any of the first to third lifting modes is in any one of them, the monitoring range A can be changed to any one of the first to third monitoring ranges A0, A11, and A12 corresponding to that mode.

[0051] In the overhead conveyor 1, the first mode is the direct downward transfer mode, the second mode is the lateral transfer mode during loading, and the third mode is the lateral transfer mode during unloading. Therefore, the monitoring range A of the monitoring sensor 10 can be changed according to each specific lifting mode.

[0052] In the overhead conveyor 1, the first monitoring range A0 extends from the monitoring sensor 10 in the reference posture toward a first direction along the vertical direction. The second monitoring range A11 extends from the monitoring sensor 10 in the reference posture toward a second direction formed by tilting the first direction by a first angle. The third monitoring range A12 extends from the monitoring sensor 10 in the reference posture toward a third direction formed by tilting the first direction by a second angle larger than the first angle. In this case, the lifting drive unit 6 is easier to tilt in the second lifting mode than in the first lifting mode, and the lifting drive unit 6 is easier to tilt in the third lifting mode than in the second lifting mode. Based on this understanding, the first to third monitoring ranges A0, A11, and A12 can be set.

[0053] In the overhead conveyor 1, a reflector 11 is provided in the holding unit 7. A monitoring sensor 10 irradiates a laser towards the reflector 11 and detects the reflected light when the laser L is reflected by the reflector 11. In this case, the monitoring sensor 10 can monitor the area below the lifting drive unit 6 (such as the swing of the holding unit 7) by whether or not the reflected light is detected.

[0054] In the overhead conveyor 1, the monitoring sensor 10 can change the orientation of the monitoring range A along the Y direction. Thus, even if there is a tilt in the lifting drive unit 6 such that one side of the Y direction is raised or lowered relative to the other side, the monitoring sensor 10 can change the orientation of the monitoring range A in accordance with the tilt to accurately monitor the area below the lifting drive unit 6.

[0055] In the overhead conveyor 1, the Y direction corresponds to the direction in which the lifting drive unit 6 can be moved via the lateral unit 4. In this case, if the moving axis of the lateral unit 4 deflects when the lifting drive unit 6 is moved laterally via the lateral unit 4, the orientation of the monitoring range A is prone to deviate along the Y direction. Therefore, in this case, the monitoring sensor 10, which can change the orientation of the monitoring range A along the Y direction, is particularly effective.

[0056] The elevated transport vehicle 1 is equipped with an adjustment mechanism that adjusts the positional relationship between the monitoring sensor 10 and the lifting drive unit 6 by changing the orientation of the monitoring range A of the monitoring sensor 10 in the X direction. In this case, the orientation of the monitoring range A of the monitoring sensor 10 in the X direction can be adjusted by the adjustment mechanism.

[0057] The overhead conveyor 1 includes a tilt detection sensor 13 for detecting the tilt of the lifting drive unit 6, and a conveyor controller 8 that adjusts the monitoring range A of the monitoring sensor 10 based on the detection result of the tilt detection sensor 13. In this configuration, by detecting the tilt of the lifting drive unit 6 using the tilt detection sensor 13 and adjusting the monitoring range of the monitoring sensor 10 based on the tilt, the conveyor controller 8 can consistently monitor, for example, the same range as before the tilt occurred. Furthermore, it can accurately monitor the area below the lifting drive unit 6.

[0058] In the overhead conveyor 1, it is not necessary to physically change the optical axis of the monitoring sensor 10 in the Y direction through a solenoid or similar means, which can suppress structural complexity and the increase in the number of adjustment points. In the overhead conveyor 1, multiple monitoring ranges A of the monitoring sensor 10 can be automatically set.

[0059] The above description describes one embodiment, but the present invention is not limited to the above embodiment. Various modifications can be made without departing from the spirit of one aspect of the invention.

[0060] In the above embodiments, when the monitoring range A is changed according to the tilt information, the tilt information is detected by a sensor or the like, and the monitoring range A is changed simultaneously. Alternatively, or in other ways, for example, a data table showing the correspondence between multiple tilt information and multiple monitoring ranges A can be stored in a storage unit (not shown) after prior teaching, and the monitoring range A can be changed based on the tilt information by referring to the data table.

[0061] In the above embodiments, the tilt information is not particularly limited, and other information may be included regarding the tilt of the lifting drive unit 6. For example, the tilt information may also include at least one of the presence or absence of the FOUP 200 and the amount of movement (stroke) of the lateral unit 4 as tilt information related to the tilt of the lifting drive unit 6. In this case, the transport vehicle controller 8 changes the monitoring range A of the monitoring sensor 10 according to at least one of the presence or absence of the FOUP 200 and the amount of movement of the lateral unit 4. In this case, the monitoring range A can be used more accurately and appropriately.

[0062] In the above embodiment, the monitoring range A is changed to any one of the first to fifth monitoring ranges A0, A11, A12, A21, and A22 of the monitoring sensor 10, but is not limited to this. The number of monitoring ranges A that are changed is not particularly limited; multiple ranges are acceptable. The monitoring range A can also be infinitely changed. In the above embodiment, the swing of the holding unit 7 is detected by the monitoring sensor 10, but the monitoring sensor 10 is not particularly limited. For example, the monitoring sensor 10 could also be a so-called downward-looking sensor, which emits a directional detection wave towards the vicinity of the descent destination of the holding unit 7 to detect foreign objects (obstacles) at the descent destination of the holding unit 7.

[0063] The structures in the above embodiments and variations are not limited to the materials and shapes described above, and various materials and shapes can be used. The structures in the above embodiments or variations can be arbitrarily applied to the structures in other embodiments or variations. A portion of the structures in the above embodiments or variations can be appropriately omitted without departing from the spirit of one aspect of the invention.

[0064] Explanation of reference numerals in the attached figures

[0065] 1... Overhead conveyor; 2... Frame unit (main body); 4... Lateral unit (lateral transfer mechanism); 6... Lifting drive unit (lifting drive unit); 7... Holding unit; 8... Conveyor controller (controller); 10... Monitoring sensor; 11... Reflector; 13... Tilt detection sensor; 200... FOUP (item); A... Monitoring range; A0... First monitoring range; A11... Second monitoring range; A12... Third monitoring range.

Claims

1. An elevated transport vehicle, characterized in that, have: A holding unit, which is configured to be able to rise and fall and is equipped with a reflector, and holds the item; A lifting drive unit that causes the holding unit to move up and down; A lateral transfer mechanism that causes the lifting drive unit to move laterally relative to the main body; A monitoring sensor is installed on the lifting drive unit to monitor the area below the lifting drive unit and can change the monitoring range; as well as The controller adjusts the monitoring range of the monitoring sensor based on information related to the tilt of the lifting drive unit relative to the horizontal plane. The monitoring sensor is a sensor that performs laser area scanning by moving a light spot along a first horizontal direction corresponding to the direction in which the lifting drive unit can be moved by the lateral transfer mechanism, and the monitoring range included in the area scanning range can be changed by changing the setting input. A laser rangefinder, which acts as a monitoring sensor and can be set to monitor a range, shines a laser beam toward the reflector. The holding unit is detected to determine whether it has swayed based on whether the reflected light is received within the set monitoring range.

2. The elevated transport vehicle according to claim 1, characterized in that, The controller stores the monitoring range of the monitoring sensor, i.e., the first to third monitoring ranges, respectively, corresponding to the first to third modes of raising and lowering the holding unit. When the lifting mode of the holding unit is the first mode, the monitoring range is changed to the first monitoring range; when the lifting mode of the holding unit is the second mode, the monitoring range is changed to the second monitoring range; and when the lifting mode of the holding unit is the third mode, the monitoring range is changed to the third monitoring range.

3. The elevated transport vehicle according to claim 2, characterized in that, The first mode is a mode in which the holding unit is raised and lowered directly below the main body. The second mode is a mode in which the holding unit, which is not holding the item, is raised or lowered while the lifting drive unit is moved laterally relative to the main body. The third mode is a mode in which the holding unit holding the item is raised or lowered while the lifting drive unit is moved laterally relative to the main body.

4. The elevated transport vehicle according to claim 3, characterized in that, The first monitoring range is the range within the monitoring sensor in the reference posture, oriented towards a first direction along the vertical direction. The second monitoring range is the range within the monitoring sensor in the reference posture, oriented towards a second direction, where the second direction is the direction that tilts the first direction by a first angle. The third monitoring range is the range of the monitoring sensor in the reference posture toward the third direction, which is a direction that tilts the first direction by a second angle larger than the first angle.

5. The elevated transport vehicle according to any one of claims 1 to 4, characterized in that, The monitoring sensor enables the orientation of the monitoring range to be changed along the first horizontal direction.

6. The elevated transport vehicle according to claim 5, characterized in that, The first horizontal direction corresponds to the direction in which the lifting drive unit can be moved by the lateral transfer mechanism.

7. The elevated transport vehicle according to claim 5, characterized in that, It has an adjustment mechanism that adjusts the positional relationship between the monitoring sensor and the lifting drive unit by changing the orientation of the monitoring range of the monitoring sensor in a second horizontal direction perpendicular to the first horizontal direction.

8. The elevated transport vehicle according to claim 6, characterized in that, It has an adjustment mechanism that adjusts the positional relationship between the monitoring sensor and the lifting drive unit by changing the orientation of the monitoring range of the monitoring sensor in a second horizontal direction perpendicular to the first horizontal direction.

9. The elevated transport vehicle according to any one of claims 1-4 and 6-8, characterized in that, The device is equipped with a tilt detection sensor, which detects the tilt of the lifting drive unit relative to the horizontal plane. The controller changes the monitoring range of the monitoring sensor based on the detection result of the tilt detection sensor.

10. The elevated transport vehicle according to claim 5, characterized in that, The device is equipped with a tilt detection sensor, which detects the tilt of the lifting drive unit relative to the horizontal plane. The controller changes the monitoring range of the monitoring sensor based on the detection result of the tilt detection sensor.

Images