Goods transport vehicle

Abstract

To realize an article transport vehicle capable of appropriately adjusting a posture of a holding part even when the inclination of the holding part changes according to the winding and unwinding of a hanging belt.SOLUTION: An article transport vehicle includes: a traveling section 25; a holding section 30; an elevating device 38; an inclination detection device 58; an inclination adjustment device 60; and an inclination control device 81 for controlling the inclination adjustment device 60, wherein the inclination adjustment device 60 is configured to adjust the inclination of the holding section 30 by acting on a target belt, which is a part of a plurality of hanging belts, to adjust a hanging height H of the holding section 30 by the target belt, and the inclination control device 81 detects the inclination of the holding section 30 by the inclination detection device 58 during the lowering of the holding section 30 to a transfer position by the lifting device 38, and performs an adjustment operation during the lowering to adjust the inclination of the holding section 30 by controlling the inclination adjustment device 60 based on a detection result by the inclination detection device 58.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to an article transport vehicle that includes a running section that runs along a running path, a holding section that holds articles, and a lifting device that raises and lowers the holding section while it is suspended. [Background technology]

[0002] An example of such an article transport vehicle is disclosed in Japanese Patent Application Laid-Open No. 2019-185499 (Patent Document 1).

[0003] The article transport vehicle disclosed in Patent Document 1 includes a running section that runs along a running path provided near the ceiling, a holding section that holds articles, and a lifting device that raises and lowers the holding section while it is suspended. This lifting device suspends the holding section by a hanging member formed of a wire, belt, or the like, and raises and lowers the holding section between a running position for running along the running path and a transfer position for transferring articles between a transfer target location and the holding section by winding or unwinding the hanging member. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2019-185499 Summary of the Invention [Problem to be solved by the invention]

[0005] Belts (hereinafter referred to as "hanging belts") are often used as hanging members, but the thickness and elongation of hanging belts vary due to manufacturing errors, etc. Therefore, the tilt of the holding part may change depending on the winding and unwinding of the hanging belt. However, it has been difficult to appropriately adjust the posture of the holding part depending on the change in tilt of the holding part between the traveling position and the transfer position.

[0006] In view of the above, the characteristic configuration of the goods transport vehicle is as follows: An article transport vehicle that transports articles, a traveling unit that travels along a travel path; a holding portion for holding the article; In a state where the holding portion is suspended by a plurality of suspension belts, The holding means is held in a running position for running along the running path by winding and unwinding. The holding part is raised and the article is moved to a transfer position for transferring the article between the transfer target location and the holding part. and a lifting device for lowering the holding unit. an inclination detection device that detects an inclination of the holding portion with respect to a horizontal plane; an inclination adjustment device that adjusts the inclination of the holding portion; a tilt control device that controls the tilt adjustment device; Equipped with the tilt adjustment device is configured to adjust the tilt of the holding unit by acting on a target belt that is a part of the plurality of hanging belts and adjusting the hanging height of the holding unit by the target belt, The tilt control device detects the tilt of the holding unit using the tilt detection device while the lifting device is lowering the holding unit to the transfer position, and controls the tilt adjustment device based on the detection result of the tilt detection device to perform a during-descent adjustment operation to adjust the tilt of the holding unit. death, The maximum speed of the holding unit during descent to the transfer position is defined as a maximum descent speed, In the lowering adjustment operation, the tilt control device detects the tilt of the holding unit a plurality of times using the tilt detection device in a measurement section in which the holding unit is lowered at a measurement speed that is a constant speed lower than the maximum lowering speed, and adjusts the tilt of the holding unit based on the detection results. The point is to [Means for solving the problem]

[0007] According to this configuration, the tilt of the holding unit is adjusted while it is descending, so the posture of the holding unit can be appropriately adjusted even if the tilt of the holding unit changes as the hanging belt is wound and unwound. Furthermore, even if there are multiple transfer target locations along the travel path and the heights of the transfer positions for each transfer target location are different, the tilt of the holding unit can be appropriately adjusted according to the height of each transfer position. Or, even if the tilt of the holding unit changes due to aging of the hanging belt or changes in the usage environment, the posture of the holding unit can be appropriately adjusted in response to the change. Furthermore, according to this configuration, the tilt of the holding unit is adjusted by the tilt adjustment device while it is descending, so the time required for the item transfer operation can be shortened. Furthermore, with this configuration, the tilt detection device detects the tilt of the holding unit while the speed is maintained constant, which prevents the detection result of the tilt of the holding unit from being affected by acceleration. Also, by using the average value of multiple detection results, the error can be reduced.

[0008] According to this configuration, the tilt of the holding unit is adjusted while it is descending, so the posture of the holding unit can be appropriately adjusted even if the tilt of the holding unit changes as the hanging belt is wound and unwound. Furthermore, even if there are multiple transfer target locations along the travel path and the heights of the transfer positions for each transfer target location are different, the tilt of the holding unit can be appropriately adjusted according to the height of each transfer position. Or, even if the tilt of the holding unit changes due to aging of the hanging belt or changes in the usage environment, the posture of the holding unit can be appropriately adjusted in response to the change. Furthermore, according to this configuration, the tilt of the holding unit is adjusted by the tilt adjustment device while it is descending, so the time required for the item transfer operation can be shortened.

[0009] Further features and advantages of the article transport vehicle will become apparent from the following description of the embodiments, which proceeds with reference to the drawings. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a front view showing an article transport facility according to a first embodiment; [Figure 2] Front view of the article transport vehicle of the first embodiment [Figure 3] FIG. 1 is a perspective view showing a holding portion of an article transport vehicle according to a first embodiment; [Figure 4] FIG. 1 is a diagram showing the arrangement of a tilt sensor, a first connecting portion, a second connecting portion, and a third connecting portion according to a first embodiment; [Figure 5] Control block diagram of the first embodiment [Figure 6] FIG. 10 is a time chart showing a descending operation according to the first embodiment; [Figure 7] FIG. 10 is a time chart showing an enlarged intermediate section of the descending operation according to the first embodiment; [Figure 8] FIG. 10 is a flowchart showing the adjustment operation during descent according to the first embodiment; [Figure 9] FIG. 10 is a flowchart showing an adjustment cancellation operation according to the first embodiment; [Figure 10] FIG. 10 is a perspective view showing a holding portion of the article transport vehicle of the second embodiment. [Figure 11] FIG. 10 is a perspective view showing a holding portion of the article transport vehicle according to the third embodiment; [Figure 12] FIG. 10 is a perspective view showing a holding portion of the article transport vehicle according to the fourth embodiment; [Figure 13] FIG. 10 is an enlarged front view of the adjustment cam drive device according to the fifth embodiment; [Figure 14] FIG. 10 is a cross-sectional view of the adjustment cam drive device of the fifth embodiment, showing a first state; [Figure 15] FIG. 10 is a cross-sectional view of the adjustment cam drive device of the fifth embodiment, showing a second state; [Figure 16] FIG. 10 is a cross-sectional view of the adjustment cam drive device of the fifth embodiment, showing a third state; [Figure 17] FIG. 10 is a cross-sectional view of the adjustment cam drive device of the fifth embodiment, showing a fourth state; DETAILED DESCRIPTION OF THE INVENTION

[0011] An embodiment of article transport vehicle 10 will be described by taking as an example a case where article transport vehicle 10 is applied to article transport equipment 100.

[0012] As shown in Figure 1, the article transport facility 100 includes an article transport vehicle 10 that transports an article W, rails 14 that form a travel path 12 on which the article transport vehicle 10 travels above the article transport facility 100, and a transfer target location 20 where the article W is transferred between the article transport vehicle 10 and the article transport vehicle 10. Here, the longitudinal direction of the travel path 12 is referred to as the path longitudinal direction X, and the width direction of the travel path 12 is referred to as the width direction Y. The width direction Y is a direction that is perpendicular to both the path longitudinal direction X and the vertical direction, i.e., the up-down direction Z.

[0013] In this embodiment, there are multiple transfer target locations 20 along the travel path 12. A support platform 22 that supports the item W is provided at each transfer target location 20. The support platform 22 is located adjacent to a processing device 24 that processes the item W. The item transport vehicle 10, for example, transports the item W from a source (not shown) to the support platform 22 before it is processed by the processing device 24, and transports the item W from the support platform 22 to a destination (not shown) after it has been processed by the processing device 24.

[0014] In this embodiment, the object W is a container that stores a processing target object to be processed by the processing device 24, and the above-mentioned "processing of the object" refers to processing of the processing target object stored in the object W. For example, the object W may be a wafer storage container (a so-called FOUP: Front Opening Unified Pod) that stores wafers, or a reticle storage container (a so-called reticle pod) that stores reticles. If the object W is a FOUP, the processing target object is a wafer. If the object W is a reticle pod, the processing target object is a reticle. The transfer target location 20 is a location where the object transport vehicle 10 and the object W are transferred, and may be, for example, the source of the object W or the destination of the object W. The transfer target location 20 may also be a support table 22 arranged adjacent to a stocker that stores the object W, a buffer that temporarily holds the object W, or the like. If there are multiple transfer target locations 20, the heights of the support tables 22 may be different from each other.

[0015] The article transport vehicle 10 includes a running section 25 that runs along the running path 12, a holding section 30 that holds an article W, and a lifting device 38. With the holding section 30 suspended by a plurality of hanging belts 40, the lifting device 38 lifts the holding section 30 to a running position P1 for running along the running path 12 by winding and unwinding the plurality of hanging belts 40, and lowers the holding section 30 to a transfer position P2 for transferring the article W between the transfer target location 20 and the holding section 30.

[0016] The lifting device 38 is connected to the traveling section 25. The lifting device 38 also has a lifting motor 44 that drives three hanging belts 40 to raise and lower the holding section 30 in the vertical direction Z between the traveling position P1 and the transfer position P2. The holding section 30 shown in FIG. 2 is located at the traveling position P1. The holding section 30 shown in FIG. 1 is located at the transfer position P2. The article transport vehicle 10 has a storage section 27 that stores the holding section 30 when the holding section 30 is located at the traveling position P1, and a cover 28 that covers the storage section 27. When the holding section 30 is located at the transfer position P2, it is positioned at a height corresponding to the support table 22 of the transfer target location 20.

[0017] Cover 28 is suspended and supported by running section 25. Cover 28 covers the upper side of storage section 27 and both sides of running section 25 in the traveling direction. In the illustrated example, running section 25 is arranged above rail 14, and cover 28 is arranged below rail 14. As shown in FIG. 2, running section 25 includes running wheels 26 that roll on rail 14, and a running motor 29 that drives running wheels 26. In the illustrated example, multiple running sections 25 are provided on article transport vehicle 10. Running motor 29 drives running wheels 26 provided on running section 25 to provide propulsive force for article transport vehicle 10 to travel.

[0018] The holding unit 30 includes a pair of gripping claws 32 and a gripping motor (not shown) that moves the pair of gripping claws 32 toward or away from each other. The holding unit 30 switches between a gripping state in which the pair of gripping claws 32 grip a flange portion of the article W and a gripping release state in which the gripping state is released by driving the gripping motor to move the pair of gripping claws 32 toward or away from each other. The holding unit 30 also includes a base 33 and a casing 34 that covers the upper part of the base 33. The pair of gripping claws 32 are arranged to protrude below the base 33. Note that various devices such as the gripping motor and the structure that moves the pair of gripping claws 32 toward or away from each other are omitted from FIGS. 2 and 3 .

[0019] The lifting device 38 includes winding pulleys 46 around which the multiple hanging belts 40 are wound, and a winding drive unit 47 that rotates and drives each of the multiple hanging belts 46. The lifting device 38 is configured to lower the holding unit 30 by unwinding the hanging belts 40 from each of the multiple winding pulleys 46, and to raise the holding unit 30 by winding the hanging belts 40 around each of the multiple winding pulleys 46. In this embodiment, the lifting device 38 includes multiple hanging belts 40. An upper portion of the hanging belt 40 is wound around the winding pulley 46, and a lower portion is fixed to the holding unit 30. The lifting device 38 rotates the winding pulley 46 in the forward direction by driving the winding drive unit 47, for example, to wind up the hanging belts 40, thereby raising the holding unit 30. Furthermore, the lifting device 38 lowers the holding unit 30 by, for example, rotating the winding pulley 46 in the reverse direction by driving the winding drive unit 47, and unwinding the hanging belt 40. By the lifting device 38 raising and lowering the holding unit 30, it becomes possible to transfer the article W between the holding unit 30 and the support base 22, which is arranged below the storage unit 27.

[0020] In this embodiment, the lifting device 38 includes three winding pulleys 46 and three hanging belts 40: a first belt 40a, a second belt 40b, and a third belt 40c, and the three winding pulleys 46 are driven by one winding drive unit 47. The winding drive unit 47 may be, for example, an elevator motor. In the illustrated example, the winding pulleys 46 include a first winding pulley 46a, a second winding pulley 46b, and a third winding pulley 46c.

[0021] In this embodiment, the article transport vehicle 10 is equipped with a hanging height detection device 54 that detects the hanging height H (m) of the holding unit 30. As shown in FIGS. 2 and 3 , the hanging height detection device 54 includes a height detection sensor 55 and a height detection reflector 56. In this embodiment, the height detection sensor 55 functions as a lifting / lowering detection device that detects whether the holding unit 30 is descending to the transfer position P2. In the illustrated example, the height detection sensor 55 is mounted on the holding unit 30. As such a height detection sensor 55, for example, a laser rangefinder or the like can be used. Note that the hanging height detection device 54 is not limited to this and may, for example, be one that detects the hanging height H (m) of the holding unit 30 by image recognition. Furthermore, the lifting / lowering detection device is not limited to this and may, for example, be one that detects whether the holding unit 30 is descending to the transfer position P2 by image recognition. Here, "mounted on the holding unit 30" means that the object to be mounted on the holding unit 30 is provided on the holding unit 30 so that it rises and falls at least together with the holding unit 30.

[0022] In this embodiment, the height detection reflector 56 is attached to the running unit 25, which is a portion that does not rise and fall together with the holding unit 30, or to a portion of the lifting device 38 on the running unit 25 side. The height detection sensor 55 is a reflective optical sensor that is attached to the upper surface 33a of the base 33, which is a portion that rises and falls together with the holding unit 30, and detects the height detection reflector 56. The upper surface 33a of the base 33 functions as a reference surface for the holding unit 30. It is also possible that the height detection reflector 56 is attached to the upper surface 33a of the base 33, and the height detection sensor 55 is attached to the running unit 25.

[0023] The article transport vehicle 10 is equipped with an inclination adjustment device 60 that adjusts the inclination Ti (rad) of the holding unit 30. In this embodiment, the inclination adjustment device 60 is mounted on the holding unit 30. The inclination adjustment device 60 is configured to adjust the inclination Ti of the holding unit 30 by acting on a target belt, which is one of the multiple suspending belts 40, and adjusting the suspension height H of the holding unit 30 by the target belt. In this embodiment, the multiple suspending belts 40 include a first belt 40a, a second belt 40b, and a third belt 40c connected to different portions of the holding unit 30. The first belt 40a, the second belt 40b, and the third belt 40c each share the suspension load of the holding unit 30. The first belt 40a and the second belt 40b are the above-mentioned target belts. The inclination adjustment device 60 adjusts the suspension height H of the target belt. That is, the tilt adjustment device 60 adjusts the position in the vertical direction Z of the portions of the holding unit 30 that are connected to the target belts, which are the first belt 40a and the second belt 40b. The first belt 40a and the holding unit 30 are connected by a first connecting portion 51. The second belt 40b and the holding unit 30 are connected by a second connecting portion 52. The third belt 40c and the holding unit 30 are connected by a third connecting portion 53. In the illustrated example, the tilt adjustment device 60 adjusts the position in the vertical direction Z of the first connecting portion 51 and the second connecting portion 52.

[0024] The first connecting portion 51, the second connecting portion 52, and the third connecting portion 53 each include a belt winding shaft 65 and a belt support portion 66 that supports the belt winding shaft 65 so that it can rotate freely relative to one another. The belt support portion 66 is fixed to the base portion 33 of the holding portion 30. The lower portion of the hanging belt 40 is wound around the belt winding shaft 65 and fastened with a belt fixing bolt 65e. An adjustment take-up motor 67 is connected to an end of the belt winding shaft 65 that is connected to a target belt, which is a part of the hanging belt 40. In the illustrated example, a first adjustment take-up motor 67a is connected to an end of the belt winding shaft 65 that is connected to the first belt 40a. Furthermore, a second adjustment take-up motor 67b is connected to an end of the belt winding shaft 65 that is connected to the second belt 40b. A fixing mechanism 69 that prevents relative rotation between the belt winding shaft 65 and the belt support part 66 is connected to the end of the belt winding shaft 65 that is connected to the suspension belt 40 that is not the target belt. In the illustrated example, the fixing mechanism 69 is connected to the end of the belt winding shaft 65 that is connected to the third belt 40c. A double nut or the like is used as the fixing mechanism 69, for example.

[0025] The article transport vehicle 10 is equipped with an inclination adjustment device 60 that adjusts the inclination Ti of the holding unit 30. In this embodiment, the inclination adjustment device 60 includes an adjustment winding device 62 that is provided separately from the winding pulley 46 and is capable of winding and unwinding the target belt. In the illustrated example, a belt winding shaft 65 connected to the target belts, the first belt 40a and the second belt 40b, a belt fixing bolt 65e, and an adjustment winding motor 67 function as the adjustment winding device 62 of the inclination adjustment device 60. When the first adjustment winding motor 67a is rotated, for example, in the forward direction, the first belt 40a is wound and the first connecting unit 51 is raised. When the first adjustment winding motor 67a is rotated, for example, in the reverse direction, the first belt 40a is unwound and the first connecting unit 51 is lowered. Similarly, when the second adjustment take-up motor 67b is rotated, for example, in the forward direction, the second belt 40b is wound and the second connecting part 52 is raised. When the second adjustment take-up motor 67b is rotated, for example, in the reverse direction, the first belt 40a is unwound and the first connecting part 51 is lowered. These operations allow the inclination adjustment device 60 to adjust the inclination Ti of the holding part 30. In this embodiment, since the inclination adjustment device 60 is provided in the holding part 30, maintenance and inspection work on the inclination adjustment device 60 can be performed by replacing the holding part 30 without stopping the article conveying equipment 100.

[0026] The article transport vehicle 10 is equipped with a tilt detection device 58 that detects the tilt Ti of the holding unit 30 relative to a horizontal plane. In this embodiment, the tilt detection device 58 includes a tilt sensor 59 attached to the holding unit 30. The tilt sensor 59 is configured to detect a tilt angle θ1 (rad) about a first detection axis S1 and a tilt angle θ2 (rad) about a second detection axis S2 that is perpendicular to the first detection axis S1. A virtual line connecting the first connecting unit 51 and the third connecting unit 53 is defined as a first virtual line L1, and a virtual line passing through the second connecting unit 52 and perpendicular to the first virtual line L1 is defined as a second virtual line L2. In this embodiment, the tilt sensor 59 is positioned so that one of the first detection axis S1 and the second detection axis S2 overlaps with the second virtual line L2 in a vertical view. In the example of FIG. 3, the second detection axis S2 of the tilt sensor 59 overlaps with the second virtual line L2 in a vertical view. The first detection axis S1 of the tilt sensor 59 is parallel to the first imaginary line L1 when viewed in the vertical direction. The first connecting portion 51, the second connecting portion 52, and the third connecting portion 53 are attached to the upper surface 33a of the base portion 33, which serves as a reference surface. In the illustrated example, the tilt sensor 59 is disposed on the second imaginary line L2. Preferably, the tilt sensor 59 is attached to the upper surface 33a of the base portion 33, which serves as a reference surface, and detects the tilt angle θ1 around the first detection axis S1 and the tilt angle θ2 around the second detection axis S2 as the tilt Ti of the upper surface 33a. Note that the tilt Ti of the holder 30 relative to the horizontal plane detected by the tilt detection device 58 is the tilt of the holder 30 in the space in which the holder 30 exists, and the detection method is not particularly limited. Therefore, when detecting the tilt Ti using the tilt sensor 59 as in this example, the reference surface of the tilt sensor 59 does not need to be horizontal; the reference surface of the tilt sensor 59 may be inclined relative to the horizontal plane.

[0027] FIG. 4 is a diagram showing the arrangement of the tilt sensor 59, the first connecting portion 51, the second connecting portion 52, and the third connecting portion 53 as viewed from above in the vertical direction Z, with a horizontal virtual axis K1 as the vertical axis, a horizontal virtual axis J1 perpendicular to the virtual axis K1 as the horizontal axis, and the vertical direction Z as the axis perpendicular to the plane of the paper. The virtual axis K1 is a straight line that overlaps with the first virtual line L1 in a vertical view and passes through the third connecting portion 53. Therefore, like the first virtual line L1, the virtual axis K1 is a straight line that is parallel to the first detection axis S1 in a vertical view. Furthermore, the virtual axis J1 is a straight line that is parallel to the second virtual line L2 and passes through the third connecting portion 53. Therefore, like the second virtual line L2, the virtual axis J1 is a straight line that is parallel to the second detection axis S2 in a vertical view. As shown in FIG. 4, the tilt angle around the virtual axis K1 parallel to the first detection axis S1 is equal to the tilt angle θ1, and the tilt angle around the virtual axis J1 parallel to the second detection axis S2 is equal to the tilt angle θ2.

[0028] In the example of FIG. 4, the tilt angle θ1 around the first detection axis S1 and the tilt angle θ2 around the second detection axis S2 are each set to 0 (rad) when the reference plane, which is the upper surface 33a of the base portion 33, is horizontal. In addition, the coordinate γ of the third connecting portion 53 is set as the origin. The coordinates ε(εj, βo K1 cosθ2, εz) are the coordinates of the tilt sensor 59 when the upper surface 33a is tilted. K1 cos θ2, δz) are the coordinates of the intersection of the line connecting the tilt sensor 59 and the second connecting part 52 and the line connecting the first connecting part 51 and the third connecting part 53 when the upper surface 33a is tilted.

[0029] The coordinates of the first connecting portion 51 when the upper surface 33a, which is the reference surface, is horizontal are defined as coordinates αo(0, αo K1 , 0), and the coordinate of the second connecting portion 52 when the upper surface 33a is horizontal is the coordinate βo (βo J1 , βo K1 , 0). In this way, the coordinate α Z is expressed by the following formula (1): In addition, the coordinate β, which is the Z coordinate of the second connecting portion 52 when the upper surface 33a is tilted, Z is expressed by the following equation (2). α Z =αo K1sinθ2 (1) β Z =βo K1 sinθ2+βo J1 sinθ1 (2)

[0030] The above coordinate α Z The magnitude of the coordinate β is used as an adjustment amount Bi1 of the first belt 40a to make the tilt Ti of the holding part 30 horizontal, for example. Z The magnitude of this is used, for example, as an adjustment amount Bi2 of the second belt 40b for horizontally adjusting the inclination Ti of the holding unit 30. In this way, by arranging the inclination sensor 59 so that one of the first detection axis S1 and the second detection axis S2 overlaps with the second virtual line L2 when viewed in the up-down direction, when using the inclination sensor 59 that detects the inclination angle of two axes, it is possible to simplify the calculation process for determining the adjustment amount Bi1 of the first belt 40a and the adjustment amount Bi2 of the second belt 40b.

[0031] 5 is an example of a control block diagram of this embodiment. The article transport vehicle 10 is equipped with a tilt control device 81 that controls the tilt adjustment device 60. In this embodiment, the tilt control device 81 is mounted on the holding unit 30.

[0032] The tilt control device 81 detects the tilt Ti of the holding unit 30 using the tilt detection device 58 while the lifting device 38 is lowering the holding unit 30 to the transfer position P2, and controls the tilt adjustment device 60 based on the detection result by the tilt detection device 58 to perform an adjustment operation during descent to adjust the tilt Ti of the holding unit 30. In this embodiment, the tilt detection device 58 detects the tilt Ti while the holding unit 30 is lowering for transfer. The detection of the tilt Ti may be performed while the holding unit 30 is lowering to transfer the item W from the transfer target location 20 to the holding unit 30, or may be performed while the holding unit 30 is lowering to transfer the item W held in the holding unit 30 to the transfer target location 20. Preferably, the tilt Ti is detected during descent when the holding unit 30 is not holding the item W, such as during descent of the holding unit 30 to transfer the item W from the transfer target location 20 to the holding unit 30.

[0033] The tilt control device 81 adjusts the tilt Ti of the holding unit 30 while the holding unit 30 is descending. Therefore, even if the tilt Ti of the holding unit 30 changes in response to the winding and unwinding of the suspending belt 40, the posture of the holding unit 30 can be appropriately adjusted. Furthermore, even if there are multiple transfer target locations 20 along the travel path 12 and the heights of the transfer positions P2 for each transfer target location 20 are different, the tilt Ti of the holding unit 30 can be appropriately adjusted in response to the heights of the respective transfer positions P2. Even if the tilt Ti of the holding unit 30 changes due to aging of the suspending belt 40 or changes in the usage environment, the posture of the holding unit 30 can be appropriately adjusted in response to the change. Furthermore, because the tilt control device 81 adjusts the tilt Ti of the holding unit 30 using the tilt adjustment device 60 while the holding unit 30 is descending, the time required for the transfer operation of the item W can be shortened. Furthermore, the position of the transfer target location 20 may be measured and learned using a jig equipped with a sensor or the like while the jig is held by the holding unit 30. When learning using such a jig, by adjusting the pair of gripping claws 32 of the holding part 30 with the tilt adjustment device 60 so that they are aligned horizontally and then performing measurements with the jig, there is no need to correct the tilt that can be adjusted with the tilt adjustment device 60 for the measurement results of the jig.

[0034] The inclination control device 81 calculates the descent speed Vd (m / s) and ascent speed Vu (m / s) of the holding unit 30 from the change over time in the hanging height H detected by, for example, the hanging height detection device 54. Here, the maximum speed of the holding unit 30 during descent to the transfer position P2 is defined as the maximum descent speed V1. In this embodiment, the inclination control device 81 detects the hanging height H by the hanging height detection device 54 at least in the section from the descent start time t0 to the descent end time te, and calculates the descent speed Vd of the holding unit 30 as needed.

[0035] The tilt control device 81 detects the tilt Ti of the holding unit 30 multiple times using the tilt detection device 58 during a measurement section Dt in which the holding unit 30 is lowered at a measurement speed Vt, which is a constant speed lower than the maximum descent speed V1, during the descent adjustment operation, and adjusts the tilt Ti of the holding unit 30 based on the multiple detection results. In this embodiment, the tilt control device 81 calculates, for example, an average value or a median value based on the tilt Ti detected multiple times during the measurement section Dt. Furthermore, the tilt control device 81 adjusts the tilt Ti of the holding unit 30 after the measurement section Dt.

[0036] The article transport vehicle 10 is equipped with a lifting control device 82 that controls the lifting device 38. When the lifting control device 82 is equipped with multiple pieces of hardware that are separated so as to be able to communicate with each other, some of the hardware may be provided in the article transport vehicle 10, and the remaining hardware may be provided in an external control device (not shown) that is independent of the article transport vehicle 10.

[0037] The lifting control device 82 executes stepwise deceleration control in which the descent speed Vd of the holding unit 30 during descent to the transfer position P2 is controlled in a maximum speed section D3 in which the holding unit 30 is lowered at the maximum descent speed V1, then decelerates from the maximum descent speed V1 to an intermediate speed V2 in a first deceleration section D4, then maintains the intermediate speed V2 in an intermediate section D5, then decelerates from the intermediate speed V2 to a pre-stop speed V3 in a second deceleration section D6, then maintains the pre-stop speed V3 in a pre-stop section D7, and stops the holding unit 30 at the hanging height H corresponding to the transfer position P2. Here, the measurement section Dt is a section within the intermediate section D5.

[0038] FIG. 6 is an example of a time chart of the lowering operation by the lift control device 82, with the vertical axis representing the lowering speed Vd (m / s) and the horizontal axis representing time t (s).

[0039] The lifting control device 82 controls the lifting device 38 so that the holding unit 30 descends at a descent start speed V4, which is, for example, a creep speed, in an initial movement section D1 (not shown) immediately after the holding unit 30 starts to descend from the travel position P1. Next, the lifting control device 82 controls the lifting device 38 so that the holding unit 30 descends at a predetermined descent acceleration A1 (m / s 2) the lifting device 38 so that the holding unit 30 descends while accelerating in the first deceleration section D4. When the descent speed Vd of the holding unit 30 reaches the maximum descent speed V1, the lifting control device 82 controls the lifting device 38 in the maximum speed section D3 so that the holding unit 30 descends at a constant speed while maintaining the maximum descent speed V1. When the holding unit 30 descends and enters the first deceleration section D4, the lifting control device 82 controls the lifting device 38 at a predetermined descent deceleration speed A2 (m / s 2 ) the lifting device 38 is controlled so that the holding part 30 is lowered while decelerating.

[0040] When the descent speed Vd of the holding unit 30 decelerates to the intermediate speed V2, the lifting control device 82 maintains the descent speed Vd at the intermediate speed V2 in the intermediate section D5 and controls the lifting device 38 so that the holding unit 30 descends at a constant speed. After the intermediate section D5 ends, the lifting control device 82 controls the lifting device 38 in the second deceleration section D6 so that the holding unit 30 decelerates from the intermediate speed V2 to a pre-stop speed V3, which is, for example, a creep speed. When the descent speed Vd of the holding unit 30 decelerates to the pre-stop speed V3, the lifting control device 82 maintains the pre-stop speed V3 in the pre-stop section D7 and controls the lifting device 38 so that the holding unit 30 descends at a constant speed. This pre-stop speed V3 may be the same as the descent start speed V4. When the holding unit 30 reaches the hanging height H corresponding to the transfer position P2, the holding unit 30 is stopped.

[0041] 7 is an example of a time chart of the lowering operation, showing an enlarged view of the intermediate section D5. In this embodiment, the tilt control device 81 detects the tilt Ti of the holding unit 30 multiple times using the tilt detection device 58 during the measurement section Dt, in which the holding unit 30 is lowered at a measurement speed Vt, which is a constant speed lower than the maximum descent speed V1. The measurement section Dt is a section within the intermediate section D5.

[0042] FIG. 8 is an example flowchart of the inclination control device 81's adjustment operation during descent. In this embodiment, the inclination control device 81 performs a measurement section determination process S11 to determine whether the holding unit 30 is within the measurement section Dt. For example, the inclination control device 81 determines that the holding unit 30 is within the measurement section Dt when the descent speed Vd of the holding unit 30 decelerates from the maximum descent speed V1 to an intermediate speed V2. If it is determined that the holding unit 30 is not within the measurement section Dt, the inclination control device 81 repeats the measurement section determination process S11 at predetermined time intervals. If it is determined that the holding unit 30 is within the measurement section Dt, the inclination control device 81 performs a tilt detection process S12, in which the inclination sensor 59 of the inclination detection device 58 detects the inclination Ti multiple times. In the example of FIG. 7, the inclination angle θ1 and the inclination angle θ2, which are the inclination Ti, are detected multiple times in the measurement section Dt within the intermediate section D5. The inclination control device 81 may be configured to detect the inclination Ti at any time by the inclination detection device 58 not only in the measurement section Dt but also in the entire section.

[0043] Next, the tilt control device 81 performs an average value calculation process S13 to calculate an average tilt value Tic from the tilt Ti of the holding unit 30 detected multiple times. In the example of Fig. 7, the average tilt angle θ1c is calculated in the tilt calculation section DL based on the tilt angle θ1 detected multiple times in the measurement section Dt. In addition, the average tilt angle θ2c is calculated in the tilt calculation section DL based on the tilt angle θ2 detected multiple times in the measurement section Dt.

[0044] After calculating the average value Tic, the inclination control device 81 performs a belt adjustment amount determination process S14 to determine the adjustment amount Bi of the target belt from the average value Tic. In the example of Fig. 7, the adjustment amount Bi1 of the first belt 40a and the adjustment amount Bi2 of the second belt 40b are calculated from the average inclination angle θ1c and the average inclination angle θ2c in the adjustment amount calculation section DM.

[0045] Once the adjustment amount Bi of the target belt is calculated, the inclination control device 81 performs the belt adjustment process S15, and the inclination adjustment device 60 performs a descent adjustment operation to adjust the suspension height H of the holder 30 by the target belt using the adjustment amount Bi. In this embodiment, the first adjustment take-up motor 67a is rotated to wind or unwind the first belt 40a by the adjustment amount Bi1 of the first belt 40a, and the second adjustment take-up motor 67b is rotated to wind or unwind the second belt 40b by the adjustment amount Bi2 of the second belt 40b. In FIG. 7, the first belt 40a is adjusted by the adjustment amount Bi1 in the adjustment section DN, and the second belt 40b is adjusted by the adjustment amount Bi2. If the adjustment of the target belt is not completed in the intermediate section D5 due to reasons such as a large adjustment amount Bi, the target belt is adjusted in the pre-stop section D7 in FIG. 6, which is a constant-speed descent section similar to the intermediate section D5. In this case, the target belt may also be adjusted in a section between the intermediate section D5 and the pre-stop section D7, for example, the second deceleration section D6. The intermediate section D5 may also be the pre-stop section D7. In other words, the intermediate speed V2 may be the same as the pre-stop speed V3. When the adjustment operation during descent is completed, the tilt control device 81 ends the control process.

[0046] The inclination control device 81 executes an adjustment cancellation operation to return the adjustment amount Bi of the target belt obtained by the inclination adjustment device 60 during the adjustment operation during descent while the holding unit 30 is rising to the traveling position P1, or after the holding unit 30 has completed rising but before the traveling unit 25 starts traveling. Fig. 9 is a flowchart of the adjustment cancellation operation. After the holding unit 30 starts rising from the transfer position P2, the inclination control device 81 executes a belt adjustment amount determination process S21 to determine whether the adjustment amount Bi determined in the belt adjustment amount determination process S14 is equal to or greater than the threshold value Bk.

[0047] If the belt adjustment amount determination process S21 is affirmative, i.e., if the adjustment amount Bi is equal to or greater than the threshold value Bk, the inclination control device 81 executes the adjustment amount cancellation process S22. In this embodiment, the inclination control device 81 executes the adjustment amount cancellation process S22 if the adjustment amount Bi1 of the first belt 40a is equal to or greater than the predetermined threshold value Bk1, if the adjustment amount Bi2 of the second belt 40b is equal to or greater than the predetermined threshold value Bk2, or if the adjustment amount Bi1 of the first belt 40a is equal to or greater than the threshold value Bk1 and the adjustment amount Bi2 of the second belt 40b is equal to or greater than the threshold value Bk2. In the adjustment amount cancellation process S22, an adjustment cancellation operation is performed to restore the adjustment amount Bi of the target belt during the adjustment operation performed by the inclination adjustment device 60 during descent. In this embodiment, the inclination control device 81 rotates the first adjustment take-up motor 67a and the second adjustment take-up motor 67b to cancel both the adjustment amount Bi1 of the first belt 40a and the adjustment amount Bi2 of the second belt 40b. As a result, the inclination Ti is returned to the inclination Ti before the downward adjustment operation was performed. Note that in the adjustment amount cancellation process S22, only the adjustment amounts Bi1 and Bi2 of the target belts that exceed the respective threshold values ​​Bk1 and Bk2, out of the adjustment amount Bi1 of the first belt 40a and the adjustment amount Bi2 of the second belt 40b, may be canceled. When the adjustment cancellation operation is completed, the inclination control device 81 ends the control process.

[0048] If the belt adjustment amount determination process S21 is negative, i.e., if the adjustment amount Bi is less than the threshold value Bk, the inclination control device 81 terminates the control process without performing the adjustment cancellation operation. In this embodiment, if the adjustment amount Bi1 of the first belt 40a is less than a predetermined threshold value Bk1 and the adjustment amount Bi2 of the second belt 40b is less than a predetermined threshold value Bk2, the inclination control device 81 terminates the control process without performing the adjustment cancellation operation. Note that, here, an example has been described in which the inclination control device 81 performs the adjustment cancellation operation when the adjustment amount Bi is equal to or greater than the specified threshold value Bk and does not perform the adjustment cancellation operation when the adjustment amount Bi is less than the threshold value Bk. However, the inclination control device 81 may be configured to perform the adjustment cancellation operation regardless of the magnitude of the adjustment amount Bi.

[0049] When the adjustment operation during descent is performed, the holding unit 30 may become tilted due to the adjustment amount Bi of the target belt when the holding unit 30 is raised to the running position P1. However, by performing the above-described adjustment cancellation operation, the adjustment amount Bi of the target belt performed during the adjustment operation during descent can be restored before the running unit 25 starts running. This prevents the running unit 25 from running while the article W held by the holding unit 30 is in a tilted state. The above-described adjustment cancellation operation may be performed while the holding unit 30 is being raised for transfer. Alternatively, it may be performed after the holding unit 30 has completed raising and reached the running position P1. In other words, it is sufficient that the tilt control device 81 performs the above-described adjustment cancellation operation before the running unit 25 starts running.

[0050] If there are multiple transfer target locations 20 along the travel path 12 and the height of the transfer position P2 for each transfer target location 20 is different, the amount of lifting and lowering of the holding unit 30 by the lifting device 38 will also be different. Therefore, the belt adjustment amount Bi and each transfer target location 20 will also be different. Even in such a case, the article transport vehicle 10 can appropriately determine the belt adjustment amount Bi in accordance with the different heights of the transfer position P2 by the above-mentioned adjustment operation during descent. Furthermore, even if the amount of lifting and lowering of the holding unit 30 is different for each transfer target location 20, the article transport vehicle 10 can prevent the running unit 25 from traveling with the article W held by the holding unit 30 in an inclined state by the above-mentioned adjustment cancellation operation.

[0051] Second Embodiment A transport vehicle according to the second embodiment will be described below with reference to Fig. 10. This embodiment differs from the first embodiment in that the tilt adjustment device 60 does not include an adjustment winding device 62, but includes an adjustment pulley driving device 162. The following description will focus on the differences from the first embodiment. Note that points that are not specifically described are the same as those in the first embodiment.

[0052] In this embodiment, the inclination adjustment device 60 includes an adjustment pulley drive device 162. The adjustment pulley drive device 162 includes adjustment pulleys 164a and 164b that are provided separately from the winding pulley 46 and arranged to contact the target belt, and adjustment drives 166a and 166b that change the positions of the adjustment pulleys 164a and 164b in the pressing direction relative to the target belt. In the example of FIG. 10 , a first adjustment drive unit 166a provided in the holding unit 30 changes the position of the first adjustment pulley 164a in the width direction Y. Furthermore, a second adjustment drive unit 166b provided in the holding unit 30 changes the position of the second adjustment pulley 164b in the width direction Y. As a result, the first adjustment pulley 164a provided in the holding unit 30 is pressed in the width direction Y against the first belt 40a, which is the target belt on which the inclination adjustment device 60 acts, causing the first belt 40a to bend. Furthermore, the second adjustment pulley 164b provided on the holding unit 30 is pressed against the second belt 40b, which is the target belt on which the tilt adjustment device 60 acts, in the width direction Y, causing the second belt 40b to flex. As the first belt 40a and the second belt 40b flex, the suspension height H by the first belt 40a and the second belt 40b increases, and the tilt Ti of the holding unit 30 can be adjusted.

[0053] The pressing direction of the adjustment pulleys 164a and 164b is not limited to the width direction Y, but may be, for example, the longitudinal direction X of the path or an oblique direction including a horizontal component. That is, any direction is acceptable as long as it increases the suspension height H of the first belt 40a and the second belt 40b and allows adjustment of the inclination Ti of the holding unit 30. In this embodiment, the pressing amount of the adjustment pulleys 164a and 164b corresponds to the adjustment amount Bi of the target belt. The first adjustment drive unit 166a and the second adjustment drive unit 166b are each configured to change the positions of the first adjustment pulley 164a and the second adjustment pulley 164b, for example, by including an actuator (not shown). In the illustrated example, the inclination adjustment device 60 is provided on the holding unit 30, so that maintenance and inspection of the inclination adjustment device 60 can be performed by replacing the holding unit 30.

[0054] Third Embodiment An article transport vehicle 10 according to the third embodiment will be described below with reference to Figure 11. This embodiment differs from the first embodiment in that the tilt adjustment device 60 does not include an adjustment winding device 62, but includes an adjustment pulley drive device 162. The following description will focus on the differences from the first embodiment. Note that points that are not specifically described are the same as those in the first embodiment.

[0055] The adjustment pulley drive device 162 includes adjustment pulleys 164a and 164b that are provided separately from the winding pulley 46 and are arranged so as to contact the target belt, and adjustment drive units 166a and 166b that change the positions of the adjustment pulleys 164a and 164b in the direction in which they press against the target belt. In the example of FIG. 11, the lifting device 38 includes a first diverting pulley 148a, a second diverting pulley 148b, and a third diverting pulley 148c in the payout path of the suspending belt 40. The first diverting pulley 148a, the second diverting pulley 148b, and the third diverting pulley 148c divert the extension direction of the suspending belt 40 from the width direction Y to the up-down direction Z. The first adjustment pulley 164a is provided between the first winding pulley 46a and the first diverting pulley 148a. The second adjusting pulley 164b is provided between the second winding pulley 46b and the second diverting pulley 148b.

[0056] The first adjustment drive unit 166a provided on the running unit 25 moves the first adjustment pulley 164a in the vertical direction Z, thereby bending the first belt 40a and increasing the suspension height H of the first belt 40a. The second adjustment drive unit 166b provided on the running unit 25 moves the second adjustment pulley 164b in the vertical direction Z, thereby bending the second belt 40b and increasing the suspension height H of the second belt 40b. This allows the tilt Ti of the holding unit 30 to be adjusted. The pressing direction of the adjustment pulleys 164a and 164b is not limited to the vertical direction Z, but may be any direction that increases the suspension height H of the first belt 40a and the second belt 40b and adjusts the tilt Ti of the holding unit 30. In this embodiment, the pressing amount of the adjustment pulleys 164a and 164b corresponds to the adjustment amount Bi of the target belt.

[0057] As shown in FIG. 11, the winding drive unit 47 (see FIG. 2) includes a winding drive shaft 48. The winding drive unit 47 rotates the winding drive shaft 48 to rotate and drive each of the multiple winding pulleys 46, namely, a first winding pulley 46a, a second winding pulley 46b, and a third winding pulley 46c. The first belt 40a, the second belt 40b, and the third belt 40c are wound around the third switching pulley 148c. The third switching pulley 148c is provided between the first adjustment pulley 164a, the second adjustment pulley 164b, and the winding drive shaft 48 (winding drive unit 47). Therefore, even if the first belt 40a and the second belt 40b are subjected to a pressing load by the first adjustment pulley 164a and the second adjustment pulley 164b on the winding drive unit 47 side of the first diverting pulley 148a and the second diverting pulley 148b, respectively, it is possible to keep the direction of the load that the winding drive unit 47 receives from the first belt 40a and the second belt 40b unchanged.

[0058] [Fourth embodiment] An article transport vehicle 10 according to a fourth embodiment will be described below with reference to Figure 12. This embodiment differs from the first embodiment in that the tilt adjustment device 60 does not include an adjustment winding device 62, but includes an adjustment pulley drive device 162. The following description will focus on the differences from the first embodiment. Note that points that are not specifically described are the same as those in the first embodiment.

[0059] The adjustment pulley drive device 162 includes adjustment pulleys 164a, 164b that are provided separately from the winding pulley 46 and are arranged so as to be in contact with the target belt, and adjustment drive units 166a, 166b that change the position of the adjustment pulleys 164a, 164b in the pressing direction against the target belt.

[0060] In the example of FIG. 12 , the first adjustment pulley 164a, which is a first diverting pulley provided by the lifting device 38 on the payout path of the first belt 40a, is movable in the vertical direction Z. The second adjustment pulley 164b, which is a second diverting pulley provided by the lifting device 38 on the payout path of the second belt 40b, is movable in the vertical direction Z. The position of the first adjustment pulley 164a is changed in the vertical direction Z by the first adjustment drive unit 166a. Furthermore, the position of the second adjustment pulley 164b is changed in the vertical direction Z by the second adjustment drive unit 166b. This allows the length of the payout path of the first belt 40a to be changed by the first adjustment drive unit 166a. Furthermore, the length of the payout path of the second belt 40b can be changed by the second adjustment drive unit 166b. This allows the hanging height H of the first belt 40a and the second belt 40b to be changed, and the inclination Ti of the holding unit 30 to be adjusted. In this embodiment, the pressing amount of the adjustment pulleys 164a and 164b corresponds to the adjustment amount Bi of the target belt.

[0061] Fifth Embodiment An article transport vehicle 10 according to the fifth embodiment will be described below with reference to Figures 13 to 17. This embodiment differs from the first embodiment in that the tilt adjustment device 60 does not include an adjustment take-up device 62, and a cam member 271 is provided between the belt support portion 66 and the holding portion 30. The following description will focus on the differences from the first embodiment. Note that points not specifically described are the same as those in the first embodiment.

[0062] In this embodiment, of the first belt 40a, second belt 40b, and third belt 40c, the first belt 40a and the second belt 40b are the target belts on which the inclination adjustment device 60 acts. Below, only the inclination adjustment device 60 acting on the first belt 40a will be described, and the inclination adjustment device 60 acting on the second belt 40b will not be described as it is a similar device. Figure 13 is an enlarged front view of the adjustment cam drive device 270. Note that Figure 13 shows the second state (Figure 15) described below.

[0063] In this embodiment, the inclination adjustment device 60 includes an adjustment cam drive device 270. The adjustment cam drive device 270 includes a cam member 271 that changes at least the distance E1 in the up-down direction Z between the holding unit 30 and the first belt 40a by being rotationally driven, and a cam rotation drive unit 290 that rotationally drives the cam member 271. In the illustrated example, the cam member 271 is rotatably supported around a cam rotation drive shaft 272 by a cam support member 233 that protrudes upward from the base unit 33. The cam member 271 is also supported by the cam support member 233 so as to be immovable in the up-down direction Z relative to the base unit 33 of the holding unit 30.

[0064] In this embodiment, the adjustment cam drive device 270 includes a cam follower 280 coupled to the first belt 40a, which is the target belt. The cam follower 280 moves back and forth at least in the vertical direction Z in response to rotation of the cam member 271 about the cam rotation drive shaft 272, thereby changing at least the distance E1 in the vertical direction Z between the holder 30 and the first belt 40a, which is the target belt. In the illustrated example, the distance E1 in the vertical direction Z is indicated by the distance between the upper surface 33a of the holder 30 and the lower end of the first belt 40a, which is the target belt. In the illustrated example, the cam follower 280 includes a roller 281 at a location where it contacts the cam member 271. The cam follower 280 is fixed to the belt support portion 66. The cam member 271 contacts the cam follower 280 (here, the roller 281) from above, and the cam member 271 is constantly biased against the roller 281 of the cam follower 280 by the weight of the holder 30. Therefore, the holding portion 30 is supported by the first belt 40a via the roller 281 of the cam follower 280. In the illustrated example, the cam follower 280 is a plate-like member equipped with the roller 281, and has a through-hole 280f for tightening and loosening the belt fixing bolt 65e.

[0065] 14 to 17 are side views of the adjustment cam drive device 270 of this embodiment. The belt support portion 66 is omitted from FIGS. 14 to 17. FIG. 14 shows a first state in which the distance E1 between the holding portion 30 and the first belt 40a in the vertical direction Z is longest. FIG. 15 shows a second state in which the cam member 271 has rotated approximately 180 degrees clockwise from the first state. FIG. 16 shows a third state in which the cam member 271 has rotated approximately 90 degrees clockwise from the second state. FIG. 17 shows a fourth state in which the cam member 271 has rotated approximately 90 degrees clockwise from the third state and the distance E1 is shortest. According to the adjustment cam drive device 270 of this embodiment, the hanging height H can be adjusted by changing the distance E1 between the holding portion 30 and the first belt 40a in the vertical direction Z, thereby appropriately adjusting the inclination Ti of the holding portion 30. In this embodiment, the amount of change in the distance E1 between the holding portion 30 and the target belt (the first belt 40a and the second belt 40b) in the vertical direction Z corresponds to the adjustment amount Bi of the target belt.

[0066] 15, in this embodiment, the adjustment cam drive device 270 includes a linear guide portion 234 that guides the cam follower 280 in the up-down direction Z. The linear guide portion 234 includes a guide pin 234e and a guide hole 234f. In the example shown in the figure, the guide pin 234e is provided in the cam follower 280, and the guide hole 234f is provided in the cam support member 233.

[0067] 13, in this embodiment, the cam rotation drive unit 290 includes a cam motor 295 and a transmission mechanism 292 that transmits the drive force of the cam motor 295 to the cam member 271. The cam member 271 is disposed on the upper surface 33a side of the base 33 of the holder 30, and the cam motor 295 is disposed on the lower surface 33b side of the base 33. This makes it possible to effectively utilize the lower surface 33b side of the base 33, which tends to become unused space, and makes it easy to prevent the holder 30 from becoming larger due to the inclusion of the adjustment cam drive device 270.

[0068] In the illustrated example, the transmission mechanism 292 includes a first gear 272a that rotates integrally with the cam rotation drive shaft 272, and a second gear 272b that rotates integrally with a drive shaft 296 of the cam motor 295. In this way, for example, by changing the diameter of the first gear 272a or the second gear 272b, the distance in the up-down direction Z between the cam member 271 and the cam motor 295 can be set to any distance. Also, for example, by making the first gear 272a and the second gear 272b intersecting-axis gears, the angle at which the cam motor 295 is disposed can be set to any direction.

[0069] Other Embodiments Next, other embodiments of the article transport vehicle 10 will be described.

[0070] (1) In the above embodiment, the tilt Ti of the holding unit 30 is adjusted so that the upper surface 33a, which serves as the reference plane, is horizontal. However, the present invention is not limited to such an example. For example, the tilt Ti of the holding unit 30 may be adjusted so that the pair of gripping claws 32 of the holding unit 30 are aligned horizontally. Furthermore, in cases where the upper surface of the support platform 22, which serves as the item placement surface of the transfer target location 20, is inclined, the tilt Ti may be adjusted to tilt the holding unit 30 in a similar manner. Furthermore, the article transport vehicle 10 may be provided with a slide mechanism that slides the holding unit 30 horizontally relative to the running unit 25, and the tilt of the holding unit 30, which corresponds to the holding unit 30 being protruded horizontally relative to the running unit 25, may also be adjusted by an adjustment operation during descent.

[0071] (2) In the above embodiment, an example was described in which an initial section D1, an acceleration section D2, a maximum speed section D3, a first deceleration section D4, an intermediate section D5, a second deceleration section D6, a pre-stop section D7, etc. were provided. However, the present invention is not limited to such an example. For example, only the acceleration section D2 may be provided and the adjustment operation during descent may be performed. Furthermore, when the distance from the travel position P1 to the transfer position P2 is short or the descent speed Vd is slow, after the start of descent, only the measurement section Dt in which the holding unit 30 is lowered at a constant measurement speed Vt may be performed, and the adjustment operation during descent may be performed.

[0072] (3) In the above embodiment, the tilt control device 81 is described as being configured to detect the tilt Ti while the holder 30 is descending. However, the present invention is not limited to such an example, and for example, the tilt control device 81 does not have to detect the tilt Ti during each descent. For example, the tilt control device 81 may learn the tilt Ti multiple times while each of the multiple transfer target locations 20 is descending, and perform an adjustment operation during descent based on the learning results.

[0073] (4) In the above embodiment, the hanging belts 40 are described as having three belts, namely, the first belt 40a, the second belt 40b, and the third belt 40c. However, the number of hanging belts 40 may be any number, for example, two. The first connecting portion 51, the second connecting portion 52, the third connecting portion 53, and the tilt sensor 59 are arranged in the same manner in the first to fifth embodiments. However, the arrangement is not limited to this and may be determined according to the number of hanging belts 40 and their connecting locations. In the above embodiment, the number of target belts acted upon by the tilt adjustment device 60 is two, namely, the first belt 40a and the second belt 40b. However, the number of target belts acted upon by the tilt adjustment device 60 may be one of the two.

[0074] (5) In the above embodiment, the inclination adjustment device 60 has been described as including one of the adjustment winding device 62, the adjustment pulley driving device 162, and the adjustment cam driving device 270. However, the inclination adjustment device 60 is not limited to this example, and may be configured to include, for example, three of the adjustment winding device 62, the adjustment pulley driving device 162, and the adjustment cam driving device 270, or may be configured to include two of them.

[0075] (6) In the first, second, and fifth embodiments, the height detection sensor 55, the tilt detection device 58, the tilt adjustment device 60, and the tilt control device 81 are mounted on the holding unit 30. However, the present invention is not limited to such an example. For example, the height detection sensor 55, the tilt detection device 58, the tilt adjustment device 60, and the tilt control device 81 may be mounted on the traveling unit 25. Furthermore, for example, if the tilt control device 81 includes multiple pieces of hardware that are separated so as to be able to communicate with each other, some of the hardware may be mounted on the holding unit 30, and the remaining hardware may be provided in an external control device that is not mounted on the holding unit 30. Furthermore, for example, the tilt control device 81 and the lift control device 82 may be a single control device rather than separate control devices.

[0076] (7) In the fifth embodiment, an example has been described in which the cam member 271 is constantly biased against the cam follower 280 by the weight of the holder 30. However, the present invention is not limited to such an example, and may be configured, for example, in which the cam member 271 is constantly biased against the cam follower 280 by an elastic member. Alternatively, the cam member 271 and the cam motor 295 may be connected to the first belt 40a, and the cam follower 280 may be supported on the base portion 33 of the holder 30 so as to be immovable in the vertical direction Z.

[0077] (8) The configurations disclosed in the above-described embodiments can be applied in combination with configurations disclosed in other embodiments, as long as no contradictions arise. Regarding other configurations, the embodiments disclosed in this specification are merely examples in all respects. Therefore, various modifications can be made as appropriate within the scope of the present disclosure.

[0078] [Summary of the above embodiment] The article transport vehicle described above will now be described.

[0079] The article transport vehicle according to the present disclosure includes: An article transport vehicle that transports articles, a traveling unit that travels along a travel path; a holding portion for holding the article; a lifting device that, while suspending the holding unit by a plurality of hanging belts, lifts the holding unit to a running position for running along the running path by winding and unwinding the plurality of hanging belts, and lowers the holding unit to a transfer position for transferring the item between a transfer target location and the holding unit; an inclination detection device that detects an inclination of the holding portion with respect to a horizontal plane; an inclination adjustment device that adjusts the inclination of the holding portion; a tilt control device that controls the tilt adjustment device; Equipped with the tilt adjustment device is configured to adjust the tilt of the holding unit by acting on a target belt that is a part of the plurality of hanging belts and adjusting the hanging height of the holding unit by the target belt, The tilt control device detects the tilt of the holding unit using the tilt detection device while the lifting device is descending the holding unit to the transfer position, and controls the tilt adjustment device based on the detection result by the tilt detection device to perform an adjustment operation during descent to adjust the tilt of the holding unit.

[0080] According to this configuration, the tilt of the holding unit is adjusted while it is descending, so the posture of the holding unit can be appropriately adjusted even if the tilt of the holding unit changes as the hanging belt is wound and unwound. Furthermore, even if there are multiple transfer target locations along the travel path and the heights of the transfer positions for each transfer target location are different, the tilt of the holding unit can be appropriately adjusted according to the height of each transfer position. Or, even if the tilt of the holding unit changes due to aging of the hanging belt or changes in the usage environment, the posture of the holding unit can be appropriately adjusted in response to the change. Furthermore, according to this configuration, the tilt of the holding unit is adjusted by the tilt adjustment device while it is descending, so the time required for the item transfer operation can be shortened.

[0081] Further, in the article transport vehicle, The maximum speed of the holding unit during descent to the transfer position is defined as a maximum descent speed, During the adjustment operation during descent, the tilt control device preferably detects the tilt of the holding part multiple times using the tilt detection device in a measurement section in which the holding part is lowered at a measurement speed that is a constant speed lower than the maximum descent speed, and adjusts the tilt of the holding part based on the multiple detection results.

[0082] With this configuration, the tilt detection device detects the tilt of the holding unit while the speed is maintained at a constant level, which prevents the detection result of the tilt of the holding unit from being affected by acceleration. Also, by using the average value of multiple detection results, the error can be reduced.

[0083] Further, in the article transport vehicle, Further provided is a lifting control device for controlling the lifting device, the lifting control device executes stepwise deceleration control in which the descent speed of the holding unit during descent to the transfer position is reduced from the maximum descent speed to an intermediate speed in a first deceleration section after a maximum speed section in which the holding unit is lowered at the maximum descent speed, then the intermediate speed is maintained in an intermediate section, then the intermediate speed is reduced from the intermediate speed to a pre-stop speed in a second deceleration section, then the pre-stop speed is maintained in a pre-stop section, and the holding unit is stopped at a hanging height corresponding to the transfer position; The measurement section is preferably a section within the intermediate section.

[0084] When the tilt of the holding part changes depending on the height of the holding part due to variations in the thickness of the hanging belt, etc., detecting the tilt of the holding part multiple times while the holding part is being raised or lowered at high speed can be easily affected by changes in tilt depending on the hanging height of the holding part. With this configuration, the tilt of the holding part is detected while the holding part is being lowered at a measurement speed that is lower than the maximum descent speed, so even when multiple detections are performed, the tilt of the holding part can be less affected by changes in tilt depending on the hanging height of the holding part. Therefore, it is easy to detect the tilt of the holding part with high accuracy.

[0085] Further, in the article transport vehicle, It is preferable that the inclination control device executes an adjustment cancellation operation to restore the adjustment amount of the target belt performed by the inclination adjustment device during the adjustment operation during descent while the holding part is rising to the running position, or after the holding part has completed rising and before the running part starts running.

[0086] When the holding unit is raised to the running position, the holding unit may become tilted due to the adjustment amount of the target belt during the adjustment operation during descent. With this configuration, the adjustment amount of the target belt during the adjustment operation during descent can be restored before the running unit starts running. Therefore, it is possible to prevent the running unit from running while the item held by the holding unit is in a tilted state.

[0087] Further, in the article transport vehicle, It is preferable that the tilt control device executes the adjustment cancellation operation when the adjustment amount is equal to or greater than a specified threshold value, and does not execute the adjustment cancellation operation when the adjustment amount is less than the threshold value.

[0088] According to this configuration, if the adjustment amount of the target belt during the lowering adjustment operation is small, it is considered that the tilt of the article held by the holding unit when the holding unit is in the running position is also small. With this configuration, since the adjustment cancellation operation is not performed in such a case, it is possible to avoid unnecessary adjustment cancellation operations and, in turn, make it easier to start running the running unit sooner.

[0089] Further, in the article transport vehicle, The tilt detection device preferably includes a tilt sensor attached to the holding portion.

[0090] According to this configuration, the tilt of the holding portion can be easily detected with high accuracy.

[0091] Further, in the article transport vehicle, the tilt sensor is configured to detect a tilt angle about a first detection axis and a tilt angle about a second detection axis orthogonal to the first detection axis; the plurality of hanging belts include a first belt, a second belt, and a third belt connected to different portions of the holding portion, the target belt is the first belt and the second belt, a portion connecting the first belt and the holding portion is a first connecting portion, a portion connecting the second belt and the holding portion is a second connecting portion, and a portion connecting the third belt and the holding portion is a third connecting portion, A virtual line connecting the first connecting portion and the third connecting portion is defined as a first virtual line, and a virtual line passing through the second connecting portion and perpendicular to the first virtual line is defined as a second virtual line, It is preferable that the tilt sensor be disposed so that one of the first detection axis and the second detection axis overlaps with the second virtual line when viewed in the up-down direction.

[0092] According to this configuration, when an inclination sensor that detects the inclination angle on two axes is used, it is possible to simplify the calculation process for determining the inclination angle of the holding part based on the detection result by the inclination sensor.

[0093] Further, in the article transport vehicle, It is preferable that the holding unit is equipped with a lifting detection device that detects whether the holding unit is descending to the transfer position, the tilt detection device, the tilt adjustment device, and the tilt control device.

[0094] According to this configuration, the tilt adjustment device mounted on the holding unit can be controlled based on the detection results of the elevation detection device and tilt detection device mounted on the holding unit, and the tilt control device mounted on the holding unit can adjust the tilt of the holding unit. In other words, the adjustment operation during descent can be completed by the device mounted on the holding unit. This makes it possible to reduce communication between the holding unit and other devices.

[0095] Further, in the article transport vehicle, the lifting device includes a winding pulley around which each of the plurality of hanging belts is wound, and a winding drive unit that rotationally drives each of the plurality of hanging belts, and is configured to lower the holding unit by unwinding the hanging belt from each of the plurality of winding pulleys, and to lift the holding unit by winding the hanging belt around each of the plurality of winding pulleys, It is preferable that the inclination adjustment device comprises at least one of an adjustment winding device that is provided separately from the winding pulley and is capable of winding and unwinding the target belt, an adjustment pulley drive device that is provided separately from the winding pulley and is arranged so as to be in contact with the target belt and has an adjustment drive unit that changes the position of the adjustment pulley in the pressing direction against the target belt, and an adjustment cam drive device that has a cam member that changes at least the vertical distance between the holding unit and the target belt by being driven to rotate, and a cam rotation drive unit that drives to rotate the cam member.

[0096] According to this configuration, it is possible to act on the target belt to adjust the hanging height of the holding portion by the target belt, and to appropriately adjust the inclination of the holding portion.

[0097] Further, in the article transport vehicle, the lifting device includes a winding pulley around which each of the plurality of hanging belts is wound, and a winding drive unit that rotationally drives each of the plurality of hanging belts, and is configured to lower the holding unit by unwinding the hanging belt from each of the plurality of winding pulleys, and to lift the holding unit by winding the hanging belt around each of the plurality of winding pulleys, The tilt adjustment device includes an adjustment cam drive device having a cam member that changes the distance between the holding portion and the target belt in at least the vertical direction by being rotationally driven, and a cam rotation drive unit that rotationally drives the cam member, the cam rotation drive unit includes a cam motor and a transmission mechanism that transmits the driving force of the cam motor to the cam member, The holding portion includes a base portion, It is preferable that the cam member is disposed on the upper surface side of the base portion, and the cam motor is disposed on the lower surface side of the base portion.

[0098] According to this configuration, the underside of the base portion, which tends to remain unused, can be effectively utilized, and it is easy to prevent the holding portion from becoming larger due to the inclusion of an adjustment cam drive device. [Industrial Applicability]

[0099] The technology disclosed herein can be used in an article transport vehicle equipped with a lifting device that raises and lowers a holding section that holds an article while it is suspended. [Explanation of symbols]

[0100] 10: Goods transport vehicle 12: Travel route 20: Transfer target location 25: Running part 30: Holding part 38: Lifting device 40: Hanging belt 40a: First belt (hanging belt) 40b: Second belt (hanging belt) 40c: Third belt (hanging belt) 46: Winding pulley 46a: 1st winding pulley 46b: Second winding pulley 46c: 3rd winding pulley 47: Winding drive unit 51: 1st connection part 52:Second connection part 53:Third connection part 55: Height detection sensor (lift detection device) 58: Tilt detection device 59: Tilt sensor 60: Tilt adjustment device 64: Adjustment winding device 81: Tilt control device 82: Lift control device 162: Adjustment pulley drive device 164a: First adjustment pulley (adjustment pulley) 164b: Second adjustment pulley (adjustment pulley) 166a: First adjustment drive unit (adjustment drive unit) 166b: Second adjustment drive unit (adjustment drive unit) 270: Adjustment cam drive device 271: Cam member 290: Cam rotation drive unit 292: Transmission mechanism 295: Cam motor

Claims

1. An article transport vehicle that transports articles, a traveling unit that travels along a travel path; a holding portion for holding the article; a lifting device that, while suspending the holding unit by a plurality of hanging belts, lifts the holding unit to a running position for running along the running path by winding and unwinding the plurality of hanging belts, and lowers the holding unit to a transfer position for transferring the item between a transfer target location and the holding unit; an inclination detection device that detects an inclination of the holding portion with respect to a horizontal plane; an inclination adjustment device that adjusts the inclination of the holding portion; a tilt control device that controls the tilt adjustment device; Equipped with the tilt adjustment device is configured to adjust the tilt of the holding unit by acting on a target belt that is a part of the plurality of hanging belts and adjusting the hanging height of the holding unit by the target belt, the tilt control device detects the tilt of the holding unit using the tilt detection device while the lifting device is lowering the holding unit to the transfer position, and controls the tilt adjustment device based on the detection result by the tilt detection device to perform an adjustment operation during descent to adjust the tilt of the holding unit; The maximum speed of the holding unit during descent to the transfer position is defined as a maximum descent speed, The inclination control device of the goods transport vehicle detects the inclination of the holding part multiple times using the inclination detection device in a measurement section in which the holding part is lowered at a constant measurement speed that is lower than the maximum descent speed during the adjustment operation during descent, and adjusts the inclination of the holding part based on the multiple detection results.

2. Further provided is a lifting control device for controlling the lifting device, the lifting control device executes stepwise deceleration control in which the descent speed of the holding unit during descent to the transfer position is reduced from the maximum descent speed in a maximum speed section to an intermediate speed in a first deceleration section, then maintains the intermediate speed in an intermediate section, then decelerates from the intermediate speed to a pre-stop speed in a second deceleration section, then maintains the pre-stop speed in a pre-stop section, and stops at a hanging height corresponding to the transfer position, The article transport vehicle according to claim 1 , wherein the measurement section is a section within the intermediate section.

3. An article transport vehicle that transports articles, a traveling unit that travels along a travel path; a holding portion for holding the article; a lifting device that, while suspending the holding unit by a plurality of hanging belts, lifts the holding unit to a running position for running along the running path by winding and unwinding the plurality of hanging belts, and lowers the holding unit to a transfer position for transferring the item between a transfer target location and the holding unit; an inclination detection device that detects an inclination of the holding portion with respect to a horizontal plane; an inclination adjustment device that adjusts the inclination of the holding portion; a tilt control device that controls the tilt adjustment device; Equipped with the tilt adjustment device is configured to adjust the tilt of the holding unit by acting on a target belt that is a part of the plurality of hanging belts and adjusting the hanging height of the holding unit by the target belt, the tilt control device detects the tilt of the holding unit using the tilt detection device while the lifting device is lowering the holding unit to the transfer position, and controls the tilt adjustment device based on the detection result by the tilt detection device to perform an adjustment operation during descent to adjust the tilt of the holding unit; The inclination control device performs an adjustment cancellation operation to restore the adjustment amount of the target belt performed by the inclination adjustment device during the descent adjustment operation while the holding part is rising to the running position, or after the holding part has completed rising and before the running part starts running.

4. 4. The article transport vehicle according to claim 3, wherein the tilt control device executes the adjustment cancellation operation when the adjustment amount is equal to or greater than a specified threshold value, and does not execute the adjustment cancellation operation when the adjustment amount is less than the threshold value.

5. An article transport vehicle that transports articles, a traveling unit that travels along a travel path; a holding portion for holding the article; a lifting device that, while suspending the holding unit by a plurality of hanging belts, lifts the holding unit to a running position for running along the running path by winding and unwinding the plurality of hanging belts, and lowers the holding unit to a transfer position for transferring the item between a transfer target location and the holding unit; an inclination detection device that detects an inclination of the holding portion with respect to a horizontal plane; an inclination adjustment device that adjusts the inclination of the holding portion; a tilt control device that controls the tilt adjustment device; Equipped with the tilt adjustment device is configured to adjust the tilt of the holding unit by acting on a target belt that is a part of the plurality of hanging belts and adjusting the hanging height of the holding unit by the target belt, the tilt control device detects the tilt of the holding unit using the tilt detection device while the lifting device is lowering the holding unit to the transfer position, and controls the tilt adjustment device based on the detection result by the tilt detection device to perform an adjustment operation during descent to adjust the tilt of the holding unit; An article transport vehicle, wherein the holding section is equipped with an elevation detection device that detects whether the holding section is descending to the transfer position, the tilt detection device, the tilt adjustment device, and the tilt control device.

6. An article transport vehicle that transports articles, a traveling unit that travels along a travel path; a holding portion for holding the article; a lifting device that, while suspending the holding unit by a plurality of hanging belts, lifts the holding unit to a running position for running along the running path by winding and unwinding the plurality of hanging belts, and lowers the holding unit to a transfer position for transferring the item between a transfer target location and the holding unit; an inclination detection device that detects an inclination of the holding portion with respect to a horizontal plane; an inclination adjustment device that adjusts the inclination of the holding portion; a tilt control device that controls the tilt adjustment device; Equipped with the tilt adjustment device is configured to adjust the tilt of the holding unit by acting on a target belt that is a part of the plurality of hanging belts and adjusting the hanging height of the holding unit by the target belt, the tilt control device detects the tilt of the holding unit using the tilt detection device while the lifting device is lowering the holding unit to the transfer position, and controls the tilt adjustment device based on the detection result by the tilt detection device to perform an adjustment operation during descent to adjust the tilt of the holding unit; the lifting device includes a winding pulley around which each of the plurality of hanging belts is wound, and a winding drive unit that rotationally drives each of the plurality of hanging belts, and is configured to lower the holding unit by unwinding the hanging belt from each of the plurality of winding pulleys, and to lift the holding unit by winding the hanging belt around each of the plurality of winding pulleys, The tilt adjustment device is an adjustment winding device that is provided separately from the winding pulley and is capable of winding and unwinding the target belt; an adjustment pulley drive device including an adjustment pulley that is provided separately from the winding pulley and arranged so as to be in contact with the target belt, and an adjustment drive unit that changes the position of the adjustment pulley in a pressing direction against the target belt; and an adjustment cam drive device including a cam member that changes the distance between the holding portion and the target belt in at least the vertical direction by being rotationally driven, and a cam rotation drive unit that rotationally drives the cam member; An article transport vehicle comprising at least one of the following:

7. An article transport vehicle that transports articles, a traveling unit that travels along a travel path; a holding portion for holding the article; a lifting device that, while suspending the holding unit by a plurality of hanging belts, lifts the holding unit to a running position for running along the running path by winding and unwinding the plurality of hanging belts, and lowers the holding unit to a transfer position for transferring the item between a transfer target location and the holding unit; an inclination detection device that detects an inclination of the holding portion with respect to a horizontal plane; an inclination adjustment device that adjusts the inclination of the holding portion; a tilt control device that controls the tilt adjustment device; Equipped with the tilt adjustment device is configured to adjust the tilt of the holding unit by acting on a target belt that is a part of the plurality of hanging belts and adjusting the hanging height of the holding unit by the target belt, the tilt control device detects the tilt of the holding unit using the tilt detection device while the lifting device is lowering the holding unit to the transfer position, and controls the tilt adjustment device based on the detection result by the tilt detection device to perform an adjustment operation during descent to adjust the tilt of the holding unit; the lifting device includes a winding pulley around which each of the plurality of hanging belts is wound, and a winding drive unit that rotationally drives each of the plurality of hanging belts, and is configured to lower the holding unit by unwinding the hanging belt from each of the plurality of winding pulleys, and to lift the holding unit by winding the hanging belt around each of the plurality of winding pulleys, The tilt adjustment device includes an adjustment cam drive device having a cam member that changes the distance between the holding portion and the target belt in at least the vertical direction by being rotationally driven, and a cam rotation drive unit that rotationally drives the cam member, the cam rotation drive unit includes a cam motor and a transmission mechanism that transmits the driving force of the cam motor to the cam member, The holding portion includes a base portion, The article transport vehicle, wherein the cam member is disposed on an upper surface side of the base portion, and the cam motor is disposed on a lower surface side of the base portion.

8. An article transport vehicle that transports articles, a traveling unit that travels along a travel path; a holding portion for holding the article; a lifting device that, while suspending the holding unit by a plurality of hanging belts, lifts the holding unit to a running position for running along the running path by winding and unwinding the plurality of hanging belts, and lowers the holding unit to a transfer position for transferring the item between a transfer target location and the holding unit; an inclination detection device that detects an inclination of the holding portion with respect to a horizontal plane; an inclination adjustment device that adjusts the inclination of the holding portion; a tilt control device that controls the tilt adjustment device; Equipped with the tilt adjustment device is configured to adjust the tilt of the holding unit by acting on a target belt that is a part of the plurality of hanging belts and adjusting the hanging height of the holding unit by the target belt, the tilt control device detects the tilt of the holding unit using the tilt detection device while the lifting device is lowering the holding unit to the transfer position, and controls the tilt adjustment device based on the detection result by the tilt detection device to perform an adjustment operation during descent to adjust the tilt of the holding unit; the tilt detection device includes a tilt sensor attached to the holding portion, the tilt sensor is configured to detect a tilt angle about a first detection axis and a tilt angle about a second detection axis orthogonal to the first detection axis; the plurality of hanging belts include a first belt, a second belt, and a third belt connected to different portions of the holding portion, the target belt is the first belt and the second belt, a portion connecting the first belt and the holding portion is a first connecting portion, a portion connecting the second belt and the holding portion is a second connecting portion, and a portion connecting the third belt and the holding portion is a third connecting portion, A virtual line connecting the first connecting portion and the third connecting portion is defined as a first virtual line, and a virtual line passing through the second connecting portion and perpendicular to the first virtual line is defined as a second virtual line, The tilt sensor is arranged so that one of the first detection axis and the second detection axis overlaps with the second imaginary line when viewed in the up-down direction.

9. The article transport vehicle according to claim 1 , wherein the tilt detection device comprises a tilt sensor attached to the holding portion.

Images