TW202335934A - Article transport apparatus - Google Patents

Abstract

An article transport apparatus 1 includes a movable body 2, a cover 3, a transfer mechanism 4, and a control unit 5. The transfer mechanism 4 includes: a holding section 10 that is capable of performing a state change between a holding state, in which an article W is held, and a release state, in which the article W is released; a turning section 20 configured to turn the holding section 10 around a vertical turning axis 4b; and an elevating section 31 configured to raise and lower the holding section 10 into and out of an accommodation region S. In a maintenance mode, in response to receiving an operation command for the transfer mechanism from the operation terminal 4, the control unit 5 determines whether the elevation height is within the interference height range, and in response to the turning angle being outside the interference height range, the control unit 5 allows the transfer mechanism 4 to be operated in accordance with the operation command, and in response to the turning angle being within the interference height range, the control unit 5 prohibits a turning operation of the holding section 10 by the turning section 20 among operations of the transfer mechanism 4 performed in accordance with the operation command.

Description

Item handling device

Field of invention The present invention relates to an article conveying device for conveying articles.

Background of the invention For example, a transportation system is disclosed in International Publication No. 2019/035286 (Patent Document 1). Hereinafter, in the description of this background art, the names and symbols in Patent Document 1 are quoted in parentheses.

This transport system (SYS) has an article transport device (ceiling transport vehicle 10), which is provided with a moving body (running part 11), a cover part (main body part 12), a transfer mechanism (transfer part 13), and Control Section (14). The moving body (running part 11) moves along the track, and the cover part (main body part 12) is installed on the moving body (running part 11) and is configured to accommodate articles (M). The transfer mechanism (transfer part 13) has a holding part (15) that holds the article (M); a rotating part (rotating mechanism 19) that rotates the holding part (15) around the rotation axis (AX); and moves part (transfer mechanism 16) to move the holding part (15) and the rotating part (rotating mechanism 19) relative to the cover part (main part 12), and the control part (14) controls the moving body (walking part 11) and Operations of each part of the transfer mechanism (transfer part 13). The article conveying device (ceiling conveyor 10) allows the use of the rotating part (rotating mechanism) when the article (M) held by the holding part (15) is in the escape position from the cover part (main part 12). 19) to prevent the object (M) from contacting the inner wall (23a) of the cover part (body part 12).

Summary of the invention Among them, when performing maintenance and inspection of the article conveying device or when a malfunction occurs in the article conveying device, the article conveying device may be operated by an operation command from an operation terminal operated by an operator. Furthermore, there is also a case where the cover portion is provided with a protruding portion protruding toward the accommodation area on the inner surface facing the accommodation area where the object is accommodated. In this type, for example, when the transfer mechanism is operated in response to an action command to convert the movement command into a predetermined posture while the holding part is accommodated in the accommodation area covered by the cover part, the movement command will cause the transfer mechanism to move. Depending on the rotation angle of the holding part at the time point, there is a possibility that the holding part may interfere (contact) with the protruding part.

Therefore, it is desired to realize an article transport device that can appropriately operate the transfer mechanism while avoiding interference between the holding portion and the protruding portion.

In view of the above, the characteristic structure of the article transport device lies in the following points: An object transporting device is used to transport objects, and is characterized by: Has: Mobile body, moving to transport the aforementioned items; The cover portion is supported by the movable body and covers at least a part of the periphery of the side of the storage area where the aforementioned items are stored during transportation; The transfer mechanism is responsible for maintaining the aforementioned items and transferring the aforementioned items between the transfer target location; and The control part controls the aforementioned moving body and the aforementioned transfer mechanism; The transfer mechanism includes: a holding part supported by the movable body and capable of changing the state between a holding state for holding the article and a release state for releasing the holding of the article; and a rotating part for rotating the holding part in an up-down direction. The rotation axis rotates; and the lifting part makes the aforementioned holding part move upward and downward between the internal position in the aforementioned accommodation area and the external position outside the aforementioned accommodation area, The cover portion has an inner surface structure facing the accommodation area, The inner surface structure includes a protruding portion, and the protruding portion is formed to protrude toward the accommodating area side at a specific point in the up-down direction, If the lifting height of the holding part by the lifting part in the transfer mechanism is within a predetermined interference height range, there may be a situation where the holding part is rotated by the rotating part and interferes with the protruding part. , if the lifting portion is used to lift the holding portion to a height outside the interference height range, even if the holding portion is rotated by the rotating portion, it will not interfere with the inner surface structure, The aforementioned control unit can execute the maintenance mode for operating the aforementioned transfer mechanism in accordance with instructions from an operation terminal operated by an operator, In the maintenance mode, if the control unit receives the action command of the transfer mechanism from the operation terminal, it determines whether the lifting height is within the interference height range. If the lifting height is outside the interference height range, Then the movement of the aforementioned transfer mechanism is performed in accordance with the aforementioned movement instructions. If the aforementioned lifting height is within the aforementioned interference height range, it is prohibited to use the aforementioned rotating portion to perform the aforementioned holding portion during the movement of the aforementioned movement mechanism in accordance with the aforementioned movement instructions. Swirling action.

According to this special structure, even if the operator inputs an incorrect operation command of the transfer mechanism in the conservative mode, if there is a possibility of interference between the holding part and the protruding part due to the rotating operation of the holding part, the holding part does not need to be operated. The rotating action, and if it is under other circumstances, the transfer mechanism can be caused to perform actions in accordance with the action instructions. Thereby, it is possible to appropriately perform the operation of the transfer mechanism in response to the operation command while avoiding interference between the holding part and the protruding part.

Further features and advantages of the technology of the present disclosure will become clearer through the following description of illustrative and non-limiting embodiments described with reference to the drawings.

1. Implementation form of article transport device The embodiment of the article transport device will be described with reference to the drawings. As shown in FIG. 1 , the article conveyance device 1 is installed between a plurality of conveyance target locations 90 in, for example, a factory or a factory facility, and moves along a movement path R to convey the article W. When W, the posture of the item W is changed.

In the following description, the direction in which the article transport device 1 travels along the movement path R is referred to as the "traveling direction X", and the direction orthogonal to the traveling direction X in a plan view is referred to as the "width direction Y". In addition, the description will be given assuming that the direction orthogonal to both the traveling direction X and the width direction Y is referred to as "vertical direction Z". Here, the front side in the traveling direction X is referred to as "front side X1" and the rear side is referred to as "rear side X2". In addition, the left and right are defined based on the state facing the front side X1 in the traveling direction X. Specifically, let the left side in the width direction Y facing the front side X1 in the traveling direction Y2" to explain.

The article W corresponds to a conveyance target object conveyed by the article conveyance device 1 . In this embodiment, the article W is a container for storing semiconductor substrates, is formed in a rectangular parallelepiped shape, and is configured to be divided into a plurality of layers to accommodate a plurality of semiconductor substrates. The upper surface and the bottom surface of the article W are in a closed state. In particular, a flange portion W1 (see FIG. 2 ) is provided on the upper surface. The flange portion W1 is held by the article transport device 1 when the article W is transported. Furthermore, an opening for allowing the semiconductor substrate to enter and exit is provided on one of the four side surfaces of the article W. The remaining three sides of the article W are constructed in a closed state.

The transfer target place 90 is a transfer starting point of the article W or a place to be a transfer destination of the article W. As shown in FIG. 1 , the transfer target locations 90 are provided at a plurality of locations along the movement path R. In the transfer target place 90, for example, the article W is processed. The transfer target location 90 includes a processing device 90 a that processes semiconductor substrates, and a delivery unit 90 b that delivers the article W to and from the article transfer device 1 . Delivery section 90b is a so-called loading port. When the semiconductor substrate originally stored in the article W received at the delivery unit 90b is taken out by the take-out device or the like provided in the processing device 90a, for example, substrate cleaning, baking, or photoresist coating or peeling are performed in the processing device 90a. processing.

The movement path R refers to a path along which the article transport device 1 moves. In the present embodiment, the movement path R is defined by a rail 99 (see FIG. 2 ) suspended and supported from the ceiling of the building in which the article transport device 1 is used. Therefore, in this embodiment, the article transport device 1 is configured as a so-called ceiling transport vehicle.

FIG. 2 is a side view of the article transport device 1 in a state where the article W is conveyed. As shown in FIG. 2 , the article transport device 1 includes a moving body 2 , a cover part 3 , a transfer mechanism 4 , a control part 5 and a height detection part 15 . The mobile body 2 moves to transport the article W. In this embodiment, the mobile body 2 is located above the rail 99 and has a traveling motor 2M that drives the wheels 2A. The traveling motor 2M rotates and drives the wheel 2A, thereby imparting a propulsive force in the traveling direction X to the moving body 2 . Movement to convey the article W means walking along the movement path R from the conveyance starting point of the article W to the conveyance destination of the article W. Therefore, the mobile body 2 travels along the movement path R from the transportation starting point of the article W to the transportation destination of the article W.

The cover part 3 is supported by the moving body 2 and covers at least a part of the periphery of the accommodation area S where the article W being transported is accommodated. "Supported by the moving body 2" means that the cover part 3 is connected and fixed to the moving body 2, and moves together with the movement of the moving body 2. In this embodiment, the cover part 3 is suspended and supported on the movable body 2 in a state located below the rail 99 . The storage area S for accommodating the article W being transported refers to an area where the article transport device 1 for the article W is arranged during transport along the movement path R from the transport starting point of the article W to the transport destination of the article W. And it is the area covered by the cover part 3 . The area where the article W is arranged in this way is covered from the side by the cover part 3, and is therefore called a storage area S. The covering (cover) of the storage area S by the cover part 3 may be the entire side (entire periphery) of the article W, or may be a part of the entire side.

In the present embodiment, the cover part 3 is configured to include a pair of side cover parts 3B that cover the article W from the side (horizontal direction), and an upper cover part 3C that covers the article W from above. In the example of FIG. 2 , each of the pair of side cover parts 3B and the upper cover part 3C are connected to each other to form the cover part 3 . Moreover, the side cover part 3B extends downward respectively from both end parts of the upper cover part 3C along the direction of the movement path R (traveling direction X). Thereby, the pair of side cover parts 3B cover the article W held in the holding part 10 from both sides of the traveling direction X respectively. In addition, the cover portion 3 is formed in a shape in which both sides and the lower part in the width direction Y are open, and is formed into an angled inverse U-shape when viewed from the outside in the width direction Y. Therefore, the accommodating area S is in a state of communication with the outside of the cover portion 3 on both sides and the lower side in the width direction Y.

The transfer mechanism 4 holds the traveling article W and transfers the article W between the transfer target location. Holding the article W means holding the article W so that it does not fall when the moving body 2 moves along the movement path R. For example, the above-mentioned holding is preferably performed by holding the flange portion W1 provided on the article W. The transfer target point refers to the transfer target place 90 corresponding to the transfer starting point of the above-mentioned article W or the transfer destination of the article W. The transfer of item W is equivalent to the delivery of item W. Therefore, when the moving body 2 moves along the movement path R, the transfer mechanism 4 grasps the flange portion W1 provided on the article W from above so that the article W does not fall. The article W is delivered between the transfer destinations, that is, the transfer target locations 90 .

In this embodiment, the transfer mechanism 4 includes the holding part 10 , the rotating part 20 , the lifting part 31 and the sliding part 32 . The holding portion 10 is supported by the movable body 2 and can be changed into a holding state for holding the article W and a release state for releasing the holding of the article W. "Supported by the moving body 2" means that like the cover portion 3, the holding portion 10 is connected to the moving body 2 and moves in response to the movement of the moving body 2. The holding state of holding the article W refers to the state of holding the flange portion W1 provided on the article W. The release state in which the holding of the article W is released is a state in which the flange portion W1 of the article W is not held. In this embodiment, the holding part 10 has a holding motor 10M and a pair of holding claws 10C. The pair of gripping claws 10C is driven by the gripping motor 10M so that the posture can be changed between the gripping posture and the release posture. The pair of holding claws 10C enters the holding posture by moving in the direction of approaching each other, and enters the releasing posture by moving in the direction of separating from each other. The flange portion W1 of the article W is gripped by the pair of gripping claws 10C in the gripping posture, so that the holding portion 10 holds the article W. The flange portion W1 is gripped by the pair of gripping claws 10C, and the flange portion W1 is gripped by the pair of gripping claws 10C, which is then changed to the release posture. , the holding unit 10 releases the holding of the article W into a release state. Since the holding part 10 holds the flange part W1, it corresponds to a chuck.

The rotating part 20 rotates the holding part 10 around the rotating axis 4b along the up-down direction. In the present embodiment, the rotating portion 20 is configured to rotate the article W around the rotating axis 4b along the vertical direction Z to change the posture of the article W. In the present embodiment, the rotating portion 20 is provided with a rotating shaft (not shown) along the vertical direction Z, and a rotating motor 20M that drives the rotating shaft. The rotation shaft is connected to the holding part 10 and is driven by the rotation motor 20M to rotate together with the holding part 10 . Thereby, the holding part 10 and the article W held by the holding part 10 can be rotated around the rotation axis 4b along the vertical direction Z.

The lifting part 31 moves the holding part 10 up and down between an internal position in the accommodation area S and an external position outside the accommodation area S. As described above, in this embodiment, the accommodating area S is covered by the cover part 3 in a state where both sides and the lower part in the width direction Y are open. The position within the accommodating area S (that is, the position included in the accommodating area S) is equivalent to the internal position. Therefore, the article W shown by the solid line in FIG. 2 is supported at an internal position. On the other hand, the position outside the accommodating area S (that is, the position not included in the accommodating area S) is equivalent to an external position. As shown by the dotted line in FIG. 2 , when the article W is placed on the delivery part 90 b , the article W is supported at an external position. The lifting part 31 is configured to move the holding part 10 (the article W held by the holding part 10) up and down between such an internal position and an external position.

In this embodiment, in response to the lifting and lowering movement of the holding part 10 by the lifting part 31, the article W held in the holding part 10 is positioned between the internal position in the storage area S and the position where the delivery part 90b is provided. Lifting and moving between. In this embodiment, the lifting part 31 has a lifting belt 30A connected to the holding part 10 and a lifting motor 31M that drives a lifting pulley (not shown) to wind up or pull out the lifting belt 30A. Thereby, by driving the lifting motor 31M, the article W held in the holding part 10 can be raised or lowered between the internal position in the accommodation area S and the delivery part 90b. By moving the article W up and down using the lifting portion 31 , the article W can be transferred to the transfer target place 90 at a different position (lower side in this example) in the up-down direction with respect to the movement path R. In addition, at this time, by adjusting the lifting height of the holding part 10 by the lifting part 31, the positional deviation of the holding part 10 relative to the transfer target place 90 can be adjusted in the vertical direction Z.

The sliding part 32 slides the holding part 10 in the horizontal direction. In this embodiment, in response to the sliding movement of the holding part 10 by the sliding part 32, the article W held in the holding part 10 slides. In this embodiment, the sliding part 32 is attached to the cover part 3 and has a sliding belt (not shown) and a sliding device that drives a sliding pulley (not shown) to wind up or pull out the sliding belt. Use motor 32M. The sliding portion 32 slides the holding portion 10 and the article W held in the holding portion 10 along the width direction Y along with the driving of the sliding motor 32M. By causing the article W to slide in the width direction Y by the sliding portion 32, when the article W is transferred, the positional deviation of the article W to the transfer target location 90 can be adjusted in the width direction Y.

The control unit 5 controls the moving body 2 and the transfer mechanism 4 . Controlling the mobile body 2 means controlling the mobile body 2 to walk or stop along the movement path R. Furthermore, controlling the transfer mechanism 4 means controlling the holding of the article W by the transfer mechanism 4 and the delivery of the article W between the transfer starting point of the article W or the transfer destination of the article W. Specifically, the control unit 5 controls the holding and release of the article W by the holding unit 10 , or controls the movement of the article W by the rotating unit 20 , the lifting unit 31 and the sliding unit 32 . The rotation control is used to deliver the item W between the transportation starting point or the transportation destination. In FIG. 2 , the control part 5 is shown to be provided in the cover part 3 , but the control part 5 may also be provided in another location different from the cover part 3 .

As mentioned above, the accommodating area S is constituted by the cover part 3, but the cover part 3 has an inner surface structure facing the accommodating area S. The "inner surface structure facing the accommodation area S" refers to the surface corresponding to the outer edge of the accommodation area S. This inner surface structure includes the inner wall surface 3A of the cover part 3 and all structures arranged closer to the accommodation area S than the inner wall surface 3A. Specifically, the inner structure includes an inner wall surface 3A of the cover part 3, a drop control part 6 for restricting the downward fall of the article W, a swing restriction mechanism 7 for restricting the swing of the object W held by the holding part 10, And sensors arranged to protrude from the accommodation area S, etc.

The inner surface structure includes a protruding portion 8 formed to protrude toward the accommodation area S side at a specific point in the up-down direction. The specific point in the up-down direction refers to a lower side (a lower point) in the accommodation area S than the holding part 10 in the vertical direction Z (for example, the holding part 10 in the reference posture described later). Protruding toward the accommodating area S side means protruding from the inner wall surface 3A of the cover portion 3 toward the accommodating area S side. Therefore, the inner surface structure has a protruding portion 8. The protruding portion 8 is disposed in the accommodation area S, lower than the holding portion 10 in the vertical direction Z, from the inner wall surface 3A of the cover portion 3 to the accommodation area. The S side protrudes. In this embodiment, the drop restricting portion 6 is exemplified as the protruding portion 8 .

The drop restriction portion 6 is disposed lower than the article W accommodated in the storage area S in the vertical direction Z, and protrudes toward the storage area S side from the inner wall surface 3A of the cover portion 3 . The drop restricting portion 6 is provided in the inner wall surface 3A of the cover portion 3 and is a pair of side surfaces facing each other across the article W held by the holding portion 10 . In addition, the drop restriction part 6 is equipped with a link mechanism not shown in the figure. When the article W held by the holding part 10 is accommodated in the accommodation area S, the pair of restriction body driving parts 6M respectively operate the link mechanism. , thereby becoming a protruding posture protruding from the side of the accommodation area S. In such a protruding posture, the drop restricting portion 6 is disposed so that at least a part thereof overlaps the article W in a vertical viewing angle along the vertical direction Z. Thereby, even if the holding part 10 is in the released state while the article W is being conveyed, the fall restricting part 6 supports the article W from the lower side, so that, for example, the article W can be restrained from falling to the floor. In addition, the drop restricting portion 6 is in a retracted posture when the transfer mechanism 4 moves the article W to a position outside the storage area S, etc. when the article W is transferred. The fall restricting portion 6 is arranged as a whole so as not to overlap with the article W from a vertical viewing angle along the vertical direction Z in the state of the retracted posture.

The swing restriction mechanism 7 includes a support portion 7A, a contact portion 7B, and a contact drive portion 7M. The support portion 7A supports the contact portion 7B. The swing restricting mechanism 7 is provided in the inner wall surface 3A of the cover part 3 and faces opposite sides across the article W held by the holding part 10 . In this example, swing limiting mechanisms 7 are respectively provided on the opposite side surfaces where the drop limiting portion 6 is provided. Furthermore, in this embodiment, the support portion 7A is driven by the contact driving portion 7M, thereby changing the posture to a protruding posture in which the contact portion 7B protrudes from the cover portion 3 to the side of the accommodating area S. , and a retracted posture in which the contact portion 7B is retracted further toward the cover portion 3 than the protruding posture. When the article W held by the holding portion 10 is accommodated in the accommodation area S, the pair of contact portions 7B assume a protruding posture, whereby the pair of contact portions 7B abut against the side surfaces of the article W from both sides. . Thereby, the swing of the article W is restricted when the article W is transported or transferred by the transfer mechanism 4 . On the other hand, when the transfer mechanism 4 moves the article W to a position outside the storage area S, such as when the article W is transferred, the pair of contact portions 7B enter the retracted posture, whereby the pair of contact portions 7B move from Item W is separated. Thereby, the article W can be moved appropriately.

Among them, FIG. 3 is an explanatory diagram of the interference height range in this embodiment, and FIG. 4 is a diagram showing the state of the article W accommodated in the accommodation area S. As shown in FIG. If the lifting height of the holding part 10 by the lifting part 31 is outside the prescribed interference height range, even if the holding part 10 is rotated by the rotating part 20, the transfer mechanism 4 will not interfere with the inner surface structure. , however, if the lifting height of the holding part 10 by the lifting part 31 is within the interference height range, the holding part 10 is rotated by the rotating part 20 and the transfer mechanism 4 (for example, the holding part 10 ) interferes with the protruding portion 8. As described above, the holding portion 10 moves up and down along the vertical direction Z by the lifting portion 31 . Therefore, the lifting height of the holding part 10 by the lifting part 31 refers to the height corresponding to the height of the holding part 10 that is moved up and down by the lifting part 31 . In FIG. 3 , the lower surface of the holding part 10 that does not include the pair of holding claws 10C is set as the reference plane 10D, and the position of the reference plane 10D of the holding part 10 when the holding part 10 rises to the highest position in the vertical direction Z is set. is the reference position RP, and the movement amount downward from the reference position RP is set as the lifting height h. "Rotating the holding part 10 by the rotating part 20" is equivalent to rotating the rotating part 20 around the rotating axis 4b along the vertical direction Z at a predetermined rotating angle. In Figure 4, such a rotation angle is shown as θ. The inner surface structure refers to the surface that constitutes the accommodation area S. In this embodiment, it corresponds to the feeling that is provided to protrude from the inner wall surface 3A of the cover part 3, the drop restriction part 6, the swing restriction mechanism 7, and the accommodation area S. Detector etc. Interference means contact in this embodiment.

As shown in FIG. 4 , at a position along the end edge of the left side Y1 in the width direction Y of the article W held by the transfer mechanism 4 , the center part in the traveling direction X is set to point Q, and the article W is When the center of rotation when performing rotational movement is set to point O, the rotation angle at which line segment OQ becomes parallel to the width direction Y is set to 0 degrees. Next, as shown in Figure 3, the upper limit value of the interference height range is set to h1, and the lower limit value is set to h2. At this time, when the reference surface 10D of the holding part 10 is not included in the interference height range, that is, when the lifting height h is smaller than h1 (in this example, when the reference surface 10D of the holding part 10 is located above h1), Or when the lifting height h is greater than h2 (in this example, the reference surface 10D of the holding part 10 is located below h2), even if the rotating part 20 is used to rotate the article W (rotating movement), The transfer mechanism 4 does not come into contact with the inner surface structure of the cover part 3 (the movement of the object W is carried out by rotating the angle θ from 0 degrees) or the sliding part 32 is used (disposed to protrude from the inner wall surface 3A, and the fall is restricted). Part 6, swing limiting mechanism 7 and sensors in the accommodation area S, etc.). However, when the reference surface 10D of the holding part 10 is included in the interference height range (in this example, when the reference surface 10D of the holding part 10 is located between h1 and h2), as shown in FIG. 4 with a two-point chain line As shown in the figure, when the article W is rotated by the rotating part 20, the transfer mechanism 4 comes into contact with the protruding part 8 (the drop restricting part 6 in this example). Similarly, when the reference plane 10D of the holding part 10 is included in the interference height range, when the article W is slid through the sliding part 32, there is contact between the transfer mechanism 4 according to the rotation angle θ at that time. to the protruding portion 8 (the drop restricting portion 6 in this example).

In this way, the range of the lifting height where the transfer mechanism 4 does not contact the inner surface structure is outside the interference height range, and there is a lifting height where the transfer mechanism 4 comes into contact with the protruding portion 8 (in this case, the drop restricting portion 6). The range is within the interference height range. Such interference height range is shown in Figure 3. As shown in Figure 3, the interference height range is based on the reference position RP, and the lifting height h is set to the range of the lifting height from h1 to h2. Therefore, when the lifting height of the reference surface 10D of the holding part 10 is smaller than h1 or larger than h2, even if the rotational movement of the article W is performed by the rotational part 20 or the article W is performed by the sliding part 32 Even with the sliding movement, the transfer mechanism 4 will not interfere with the inner surface structure of the cover part 3 .

The height of the holding part 10, that is, the lifting height of the holding part 10, may be configured to be detected by the height detection part 15 (see FIGS. 2 and 3). If the height detection unit 15 is configured to directly detect the lifting height h of the holding unit 10 from the reference position RP, a distance sensor that detects the distance from the reference position RP to the holding unit 10 may be used. Furthermore, it is preferable to detect the change amount of the detection value of the distance sensor there as the lifting height h based on the state in which the reference surface 10D of the holding part 10 is located at the reference position RP. Furthermore, if the article transport device 1 is configured to include an encoder that detects the rotation amount of the lifting motor 31M, the height detecting unit 15 may be configured to calculate and detect the height of the holding unit 10 from the reference position RP based on the detection result of the encoder. Lifting height h. If the height detection unit 15 uses the rotation amount detected by the encoder to calculate the lifting height h, it is preferable to have a device that can continue to store the rotation amount detected by the encoder in advance even when the power supply to the encoder or the height detection unit 15 is stopped. Memory Department. Here, "preliminarily continuously stored" means that even when the power supply to the encoder or the height detection unit 15 is stopped, the rotation amount detected by the encoder will not disappear and is stored in advance.

As shown in FIG. 5 , the detection result (calculation result) of the lifting height of the holding part 10 by the height detection part 15 is transmitted to the control part 5 . Thereby, the control unit 5 can determine whether the lifting height is within the interference height range based on the detection result of the height detection unit 15 . Specifically, if the detection result of the height detection part 15, that is, the calculation result of the lifting height of the reference surface 10D of the holding part 10 is between h1 and h2, the control part 5 determines that the lifting height of the holding part 10 is within the interference height range. .

As shown in FIG. 5 , in the article transport device 1 , the control unit 5 is configured to operate the transfer mechanism 4 in accordance with instructions from the operation terminal 100 operated by the operator. The operator refers to a person who performs management, maintenance, etc. of the article transport device 1 . The operation terminal 100 refers to a terminal connected to the control unit 5 through wires or wirelessly, in addition to the transfer mechanism 4, and capable of remotely operating each functional unit of the article transport device 1 described above. When performing maintenance and inspection on the article conveying device 1 or when a malfunction occurs in the article conveying device 1 , the operator can operate the operation terminal 100 to send an operation command to cause the moving body 2 of the article conveying device 1 to have the holding portion 10 , the transfer mechanism 4 of the rotating part 20, the lifting part 31 and the sliding part 32 operates. In particular, the mode in which the transfer mechanism 4 is operated in accordance with instructions from the operation terminal 100 operated by the operator is called a maintenance mode.

In such a maintenance mode, when the control unit 5 receives an operation command of the transfer mechanism 4 from the operation terminal 100, it determines whether the lifting height is within the interference height range. In this example, the operation command of the transfer mechanism 4 refers to a reference posture recovery movement command for setting the postures of the rotating portion 20 , the lifting portion 31 , and the sliding portion 32 to a predetermined reference posture. The prescribed reference posture refers to a posture that becomes a predetermined reference posture. For example, the reference posture of the rotating part 20 refers to the above-mentioned posture in which the rotating angle is 0 degrees. For example, the reference posture of the lifting portion 31 is a posture in which the holding portion 10 is located near the upper limit of the lifting movement range. For example, the reference posture of the sliding portion 32 is a posture in which the holding portion 10 is located near the center of the sliding movement range. Therefore, in this example, when the rotating part 20, the lifting part 31, and the sliding part 32 are all in the reference posture, the entire article W held in the holding part 10 (the holding part 10 in the reference posture) is accommodated in the container. Set inside area S. Thus, the reference posture is called the so-called starting point. The instruction for the operation of returning the postures of the rotating part 20, the lifting part 31, and the sliding part 32 to such a reference posture is equivalent to the instruction for the reference posture restoration operation. When the control unit 5 receives an instruction for the reference posture recovery operation from the operation terminal 100, it determines whether the lifting height of the holding unit 10 is within the interference height range. The determination of the lifting height is based on the detection result of the above-mentioned height detection part 15.

If the lifting height of the holding part 10 is outside the interference height range, even if the rotating part 20 rotates the article W or the sliding part 32 slides the article W, the transfer mechanism 4 will still move. It will not come into contact with the inner surface structure of the cover part 3. Therefore, if the result of the above determination is that the lifting height of the holding part 10 is outside the interference height range, the control part 5 executes the operation of the transfer mechanism 4 in accordance with the operation command from the operation terminal 100 . Specifically, the control unit 5 drives the holding motor 10M, the rotation motor 20M, the lifting motor 31M, and the sliding motor 32M respectively. Thereby, the transfer mechanism 4 is operated according to the instruction of the operator who operates the operation terminal 100 .

On the other hand, if the lifting height of the holding portion 10 is within the interference height range, when the rotational movement of the article W by the rotational portion 20 or the sliding movement of the article W by the sliding portion 32 is performed, , the transfer mechanism 4 may come into contact with the protruding part 8 (the drop restricting part 6 in this example). Therefore, when the lifting height of the holding part 10 is within the interference height range, the control part 5 prohibits the rotating action of the holding part 10 by the rotating part 20 during the operation of the transfer mechanism 4 according to the action command. The situation where the lifting height of the holding part 10 is within the interference height range refers to the situation where the lifting height of the holding part 10 is within the interference height range as a result of the above determination. The movement of the transfer mechanism 4 according to the movement command refers to the moving body 2 of the article transport device 1 and the transfer mechanism 4 (including the holding part 10 and the rotating part) in response to the movement command sent by the operator operating the operation terminal 100. 20. The operation of the transfer mechanism 4) of the lifting part 31 and the sliding part 32. Therefore, prohibiting the rotating action of the holding part 10 by the rotating part 20 during the operation of the transfer mechanism 4 according to the action command means that the holding part 10, the rotating part 20, the lifting part 31 and the sliding part are prohibited. During the operation of the transfer mechanism 4 of the part 32, the rotation of the holding part 10 by the rotation part 20 is prohibited, and the movement of the holding part 10, the lifting part 31 and the sliding part 32 is allowed.

In this embodiment, when the operation command of the transfer mechanism 4 is received from the operation terminal 100 in the maintenance mode and the lifting height of the holding part 10 is within the interference height range, in addition to the movement of the holding part 10 using the rotating part 20 In addition to the rotational movement, the control unit 5 also prohibits the sliding movement of the holding unit 10 by the sliding unit 32. In this case, the control unit 5 prohibits the use of rotation during the operation of the transfer mechanism 4 according to the operation command (the operation of the transfer mechanism 4 including the holding part 10, the rotating part 20, the lifting part 31 and the sliding part 32). Both the rotational movement of the holding part 10 by the moving part 20 and the sliding movement of the holding part 10 by the sliding part 32 allow the movement of the holding part 10 and the lifting part 31.

In this way, if the current posture of the transfer mechanism 4 is such that the transfer mechanism 4 may come into contact with the inner surface structure of the cover part 3 when the holding part 10 is moved, the control part 5 will use the rotating part 20 to hold the part. The rotating movement of the holding part 10 and the sliding movement of the holding part 10 by the sliding part 32 are prohibited. Thereby, it is possible to prevent the holding part 10 from coming into contact with the inner surface structure of the cover part 3 due to an operator's operating error or the like.

In addition, the control unit 5 may be configured to prohibit the use of rotation when the operation command of the transfer mechanism 4 is received from the operation terminal 100 in the maintenance mode and the lifting height of the holding unit 10 is within the interference height range. The holding part 10 is rotated by the part 20, and if the action command includes a lifting action by the lifting part 31, the lifting action is executed. If the lifting height becomes a height outside the interference height range, the action command is also executed. The rotating portion 20 is used to rotate the holding portion 10 . The maintenance mode refers to a mode in which the transfer mechanism 4 is operated in accordance with instructions from the operation terminal 100 operated by the operator. As described above, the control unit 5 receives the operation command of the transfer mechanism 4 from the operation terminal 100, and when the lifting height of the holding unit 10 is within the interference height range, it prohibits the holding unit 10 using the rotating unit 20. spinning action. This prevents the holding portion 10 from contacting the inner surface structure of the cover portion 3 . Moreover, if the action command includes a lifting action using the lifting part 31, first, perform the lifting action of the lifting part 31 so that the reference surface 10D of the holding part 10 becomes a height outside the interference height range, and then execute the use according to the action command. The rotating part 20 performs the rotating action of the holding part 10. Thereby, even if the rotating part 20 rotates according to the action command to rotate the holding part 10, the holding part 10 can still be moved without contacting the inner surface structure of the cover part 3.

FIG. 6 is a flowchart showing the processing of the control unit 5 described above. First, when the control unit 5 receives an operation command from the operation terminal 100 (step #10: Yes), the process starts. When the control unit 5 receives the operation command from the operation terminal 100, the control unit 5 determines the lifting height of the holding unit 10. If the lifting height of the holding part 10 is outside the interference height range (step #11: Yes), the control part 5 operates the transfer mechanism 4 according to the received operation command (step #12). When the operation according to the operation instruction is completed, the control unit 5 ends the process.

In step #11, if the lifting height of the holding part 10 determined by the control part 5 is outside the non-interference height range (step #11: No), the control part 5 prohibits the rotation of the holding part 10 by the rotating part 20. Action (Step #13). Furthermore, if the operation command received from the operation terminal 100 includes the sliding movement of the holding part 10 using the sliding part 32 (step #14: Yes), the control part 5 also prohibits the holding part 10 using the sliding part 32. 10. Sliding movement (step #15).

In step #15, if the sliding movement of the holder 10 using the sliding part 32 is prohibited (step #15), or in step #14, the movement command received from the operation terminal 100 does not include the sliding movement of the holding part 10 using the sliding part 32 If the sliding movement of the holding part 10 is performed (step #14: No), it is determined whether the operation command received from the operation terminal 100 includes the lifting action of the holding part 10 by the lifting part 31 (step #16).

If the action command received from the operation terminal 100 includes the lifting action of the holding part 10 using the lifting part 31 (step #16: Yes), the control part 5 executes the holding part 31 by using the lifting part 31 in accordance with the received action command. Lifting and lowering action of part 10 (step #17). This lifting operation is performed until the lifting height of the holding portion 10 becomes outside the interference height range (step #18: No). When the lifting height of the holding part 10 is outside the interference height range (step #18: Yes), the control part 5 ends the lifting operation of the holding part 10 by the lifting part 31 (step #19). Next, the control unit 5 executes the rotation operation of the holding unit 10 using the rotation unit 20 in accordance with the operation command received from the operation terminal 100 (step #20). Furthermore, although it is not shown in the flowchart at this time, in step #14, if the operation command received from the operation terminal 100 includes the sliding movement of the holding part 10 using the sliding part 32 (step #14: No) , it is preferable to execute the sliding movement of the holding part 10 using the sliding part 32 according to the action command received from the operation terminal 100 after the processing of step #20. When the operation according to the operation instruction is completed, the control unit 5 ends the process.

On the other hand, in step #16, if the operation command received from the operation terminal 100 does not include the lifting operation of the holding unit 10 by the lifting unit 31 (step #16: No), the control unit 5 does not perform the transfer. The mechanism 4 operates and ends the process. At this time, the control unit 5 preferably displays a message that "the lifting height (of the holding part 10) is within the interference height range" on the display screen 100A of the operation terminal 100, or displays the holding part 10 and the cover part as shown in FIG. 7 3. The inner surface of the structure is a contact position or a figure of a possible contact position. Alternatively, it is preferable to output a sound from the speaker 100B of the operation terminal 100 saying "the lifting height (of the holding part 10) is within the interference height range". Of course, other messages can also be displayed or sounds output. Moreover, if the article conveying device 1 is equipped with a display device, the above-mentioned message may be displayed on the display device, and if the article conveying device 1 is equipped with a speaker, the above-mentioned sound may be output from the speaker.

If the lifting height of the holding part 10 is within the interference height range, the control part 5 may not only perform the lifting action so that the lifting height of the holding part 10 falls outside the interference height range, but may also perform the lifting operation of the holding part 10 using the rotating part 20 The rotating action or the sliding movement of the holding part 10 using the sliding part 32 prevents the transfer mechanism 4 from contacting the inner surface structure of the cover part 3 and moves the transfer mechanism 4 according to the action command received from the operation terminal 100. Loading mechanism 4 actions.

2. Other embodiments of the article transport device Next, other embodiments of the article transport device 1 will be described.

(1) In the above-mentioned embodiment, the article transport device 1 has been described as an example of a so-called ceiling transport vehicle. However, it is not limited to such a structure. For example, the article transport device 1 may also be various transport vehicles such as an unmanned transport vehicle or a tracked trolley. Alternatively, it may be a transport device that does not move along the track 99 (such as a drone, etc.).

(2) In the above-described embodiment, the protruding portion 8 is used as the drop restricting portion 6 in the description. However, it is not limited to such a structure. The protruding portion 8 may also be a sensor or the like provided to protrude from the inner wall surface 3A of the cover portion 3 , the swing limiting mechanism 7 , or the accommodating area S.

(3) In the above embodiment, the transfer mechanism 4 includes the sliding portion 32 as an example. However, the transfer mechanism 4 is not limited to this structure and may not include the sliding part 32 . In this case, the control unit 5 is configured to prohibit only the rotation of the holder 10 by the rotation unit 20 if the lifting height of the holder 10 is within the interference height range.

(4) In the above embodiment, the inner surface is configured as the surface that constitutes the accommodation area S, and is equivalent to the inner wall surface 3A of the cover part 3, the drop restriction part 6, the swing restriction mechanism 7, and is provided to protrude from the container. Sensors etc. located in the area S are explained. However, if the inner surface structure is not provided with the drop restriction part 6, the swing restriction mechanism 7, or the sensor disposed protruding from the accommodation area S, it only corresponds to the inner wall surface 3A of the cover part 3.

(5) In the above embodiment, it has been explained that the control unit 5 prohibits the rotation of the holder 10 by the rotation unit 20 if the lifting height of the holder 10 is within the interference height range, and if the operation command includes the use of The lifting portion 31 performs the lifting and lowering operation of the holding portion 10. If the lifting height reaches a height outside the interference height range, the swinging portion 20 also performs the swinging motion of the holding portion 10 in accordance with the motion command. However, it is not limited to such a structure. When the lifting height of the holding part 10 is within the interference height range, the control part 5 may prohibit the rotation of the holding part 10 by the rotating part 20 and prohibit the use of the lifting part. 31 performs the lifting and lowering operation of the holding part 10.

(6) In the above embodiment, the position of the reference surface 10D of the holding part 10 when the holding part 10 is raised to the highest position in the vertical direction Z is set as the reference position RP, and the amount of downward movement from the reference position RP is is the lifting height h. However, the structure is not limited to this. For example, the base surface 10D of the holding portion 10 (not including the lower surface of the holding portion 10 without the pair of holding claws 10C) when the holding portion 10 rises to the highest position in the vertical direction Z may be ) is different from each other (for example, the position on the upper surface of the holding part 10) is set as the reference position RP, and the downward movement amount from the reference position RP is set as the lifting height h. Alternatively, a predetermined position of the holding part 10 (for example, the position of the lower surface or the position of the upper surface) when the holding part 10 drops to the lowest position in the vertical direction Z may be set as the reference position RP, and the reference position RP will be moved from the reference position RP. The upward movement amount is set as the lifting height h. Furthermore, the lifting height may be the height from any one of the upper end, the center, the lower end, etc. of the interference height range.

(7) In the above-described embodiment, the following configuration has been exemplified and explained. The height detection unit 15 may be configured using a distance sensor, or may be detected based on the detection result of an encoder that detects the rotation amount of the lifting motor 31M. Lifting height. However, the structure is not limited to this. For example, the capacitance sensor may be arranged along the moving direction (vertical direction Z) of the holding part 10 and the holding part 10 may be detected based on the detection result of the capacitance sensor. The lifting height may also be configured to detect the lifting height of the holding part 10 based on changes in resistance value or impedance.

(8) In the above-mentioned embodiment, it has been explained that the operation command is a command for the reference posture recovery operation to set the postures of the rotating part 20, the lifting part 31, and the sliding part 32 to a predetermined reference posture. However, it is not limited to such a structure, and the action command may also be other postures different from the predetermined reference posture (for example, a posture that is easy to perform maintenance, etc.).

(9) Furthermore, the configuration disclosed in each of the above embodiments may be combined with the configuration disclosed in other embodiments as long as there is no contradiction. Regarding other configurations, the embodiments disclosed in this specification are merely illustrations from all viewpoints. Therefore, various changes can be appropriately made within the scope that does not deviate from the gist of this disclosure.

3. Summary of the above embodiments

Hereinafter, an outline of the article transport device described above will be described.

An article conveying device is an article conveying device for conveying articles, and is characterized by: Has: Mobile body, moving to transport the aforementioned items; The cover portion is supported by the movable body and covers at least a part of the periphery of the side of the storage area where the aforementioned items are stored during transportation; The transfer mechanism is responsible for maintaining the aforementioned items and transferring the aforementioned items between the transfer target location; and The control part controls the aforementioned moving body and the aforementioned transfer mechanism; The transfer mechanism includes: a holding part supported by the movable body and capable of changing the state between a holding state for holding the article and a release state for releasing the holding of the article; and a rotating part for rotating the holding part in an up-down direction. The rotation axis rotates; and the lifting part lifts and moves the holding part between the internal position in the accommodating area and the external position outside the accommodating area, The cover portion has an inner surface structure facing the accommodation area, The inner surface structure includes a protruding portion, and the protruding portion is formed to protrude toward the accommodating area side at a specific point in the up-down direction, When the lifting height of the holding part is within a predetermined interference height range when the lifting part is used in the transfer mechanism, there may be a situation where the holding part is rotated by the rotating part and interferes with the protruding part. When the lifting height of the holding part by the lifting part is outside the interference height range, even if the holding part is rotated by the rotating part, it will not interfere with the inner surface structure. The control unit is capable of executing a maintenance mode in which the transfer mechanism is operated in accordance with instructions from an operation terminal operated by an operator, In the maintenance mode, if the control unit receives the action command of the transfer mechanism from the operation terminal, it determines whether the lifting height is within the interference height range. If the lifting height is outside the interference height range, Then the movement of the aforementioned transfer mechanism is performed in accordance with the aforementioned movement instructions. If the aforementioned lifting height is within the aforementioned interference height range, it is prohibited to use the aforementioned rotating portion to perform the aforementioned holding portion during the movement of the aforementioned movement mechanism in accordance with the aforementioned movement instructions. Swirling action.

According to this structure, even if the operator inputs an incorrect operation command of the transfer mechanism in the maintenance mode, the rotation operation of the holding part is still not performed, and in other cases, the transfer mechanism can be made to operate in accordance with the operation command. Thereby, while avoiding interference between the holding part and the protruding part, the transfer mechanism can be properly operated in response to the operation command.

Preferably, the control unit receives an operation command of the transfer mechanism from the operation terminal in the maintenance mode, and when the lifting height is within the interference height range, the control unit prohibits the use of the rotating unit. The rotational action of the aforementioned holding part, and if the aforementioned action command includes the lifting action of the aforementioned holding part using the aforementioned lifting part, then the lifting action is performed, and if the aforementioned lifting height becomes a height outside the aforementioned interference height range, the aforementioned action is followed The instruction also executes the rotating action of the holding part using the rotating part.

According to this configuration, even if the operator inputs an incorrect operation command of the transfer mechanism in the maintenance mode and the rotational movement of the holding part is prohibited, if the holding part performs the turning action by performing the lifting action, the holding part will also When it is at a height that does not interfere with the protruding part, the rotating action of the holding part is also performed according to the action command. Therefore, while avoiding interference between the holding portion and the protruding portion, the transfer mechanism can be appropriately operated in response to the operation command.

Moreover, preferably, it further includes a height detection part for detecting the height of the holding part; The control unit determines whether the lifting height is within the interference height range based on the detection result by the height detection unit.

According to this configuration, when the control unit cannot determine the lifting height of the holding unit based on the control results so far, for example, when power is started to be supplied to an article transport device that is not powered, the height detection unit can appropriately determine the height of the holding unit. Lifting height.

Furthermore, preferably, the transfer mechanism further includes a sliding portion, The sliding part causes the holding part to slide and move in a horizontal direction, In the maintenance mode, when the control unit receives an action command from the operation terminal and the transfer mechanism, and the lifting height is within the interference height range, in addition to using the rotating unit to perform the rotating operation of the holding unit, , it is also prohibited to use the sliding part to perform the sliding movement of the holding part.

In the article transport device, even if the holding part is not rotated, the position of the holding part may move in the horizontal direction due to the sliding movement, and the holding part may interfere with the protruding part. Therefore, according to this configuration, such interference can be appropriately avoided.

Industrial availability The technology disclosed in the present disclosure can be used in an article conveying device for conveying articles.

1: Item transport device 2:Moving body 2A: Drive wheel 2M: Travel motor 3: Cover part 3A: Inner wall surface 3B: Side cover part 3C: Upper cover part 4:Transfer mechanism 4b: Rotating axis 5:Control Department 6:Fall restriction part 6M:Drive Department 7: Swing limiting mechanism 7A: Support part 7B:Butt part 7M: Contact drive part 8:Protrusion 10:Maintenance Department 10C: Holding claw 10D: datum plane 10M: Control motor 15:Height detection department 20: Rotating part 20M: Rotation motor 30A: Lifting belt 31:Lifting part 31M:Lifting motor 32:Sliding part 32M: Slide motor 90: Transfer target place 90a: Processing device 90b: Delivery Department 99:Orbit 100: Operation terminal 100A:Display screen 100B: Speaker h: Lifting height h1: The upper limit of the interference height range h2: lower limit of interference height range O:point Q:Point R: moving path RP: reference position S: Accommodation area W: Item W1: Flange part X: direction of travel X1: Front side X2: Rear side Y: width direction Y1:left Y2:right side Z: vertical direction #10~#20: Steps

FIG. 1 is a diagram showing a usage form of the article transport device. Figure 2 is a side view of the article transport device. Figure 3 is a diagram showing the interference height range. FIG. 4 is a diagram showing a state of articles stored in a storage area. FIG. 5 is a control block diagram of control of the transfer mechanism by the control unit. FIG. 6 is a flowchart showing the steps of controlling the transfer mechanism by the control unit. FIG. 7 is a diagram showing an example of notification in case of interference.

1: Item transport device

2:Moving body

2A: Drive wheel

2M: Wheels for traveling

3: Cover part

3A: Inner wall surface

3B: Side cover part

3C: Upper cover part

4:Transfer mechanism

4b: Rotating axis

5:Control Department

6:Fall restriction part

6M:Drive Department

7: Swing limiting mechanism

7A: Support part

7B:Butt part

7M: Contact drive part

8:Protrusion

10:Maintenance Department

10C: Holding claw

10M: Control motor

15:Height detection department

20: Rotating part

20M: Rotation motor

30A: Lifting belt

31:Lifting part

31M:Lifting motor

32:Sliding part

32M: Slide motor

90b: Delivery Department

99:Orbit

R: moving path

S: Accommodation area

W: Item

W1: Flange part

X: direction of travel

Y: width direction

Z: vertical direction

Claims (4)

An article conveying device is an article conveying device for conveying articles, and is characterized by: Has: Mobile body, moving to transport the aforementioned items; The cover portion is supported by the movable body and covers at least a part of the periphery of the side of the storage area where the aforementioned items are stored during transportation; The transfer mechanism is responsible for maintaining the aforementioned items and transferring the aforementioned items between the transfer target location; and The control part controls the aforementioned moving body and the aforementioned transfer mechanism; The transfer mechanism includes: a holding part supported by the movable body and capable of changing the state between a holding state for holding the article and a release state for releasing the holding of the article; and a rotating part for rotating the holding part in an up-down direction. The rotation axis rotates; and the lifting part makes the aforementioned holding part move upward and downward between the internal position in the aforementioned accommodation area and the external position outside the aforementioned accommodation area, The aforementioned cover portion has an inner surface structure facing the aforementioned accommodation area, The inner surface structure includes a protruding portion, and the protruding portion is formed to protrude toward the accommodating area side at a specific point in the up-down direction, If the lifting height of the holding part by the lifting part in the transfer mechanism is within a predetermined interference height range, there may be a situation where the holding part is rotated by the rotating part and interferes with the protruding part. , if the lifting portion is used to lift the holding portion to a height outside the interference height range, even if the holding portion is rotated by the rotating portion, it will not interfere with the inner surface structure, The control unit is capable of executing a maintenance mode in which the transfer mechanism is operated in accordance with instructions from an operation terminal operated by an operator, In the maintenance mode, if the control unit receives the action command of the transfer mechanism from the operation terminal, it determines whether the lifting height is within the interference height range. If the lifting height is outside the interference height range, Then the movement of the aforementioned transfer mechanism is performed in accordance with the aforementioned movement instructions. If the aforementioned lifting height is within the aforementioned interference height range, it is prohibited to use the aforementioned rotating portion to perform the aforementioned holding portion during the movement of the aforementioned movement mechanism in accordance with the aforementioned movement instructions. Swirling action. The article transport device of Claim 1, wherein the control unit receives an action instruction of the transfer mechanism from the operation terminal in the maintenance mode, and when the lifting height is within the interference height range, the use of the rotary motion is prohibited. The moving part performs the rotating action of the holding part, and if the action command includes using the lifting part to perform the lifting action of the holding part, then the lifting action is performed, and if the lifting height becomes a height outside the interference height range, Then, the rotating action of the holding part by using the rotating part is also executed according to the aforementioned action command. The article transport device of claim 1 or 2 further includes a height detection part for detecting the height of the holding part; The control unit determines whether the lifting height is within the interference height range based on the detection result by the height detection unit. The article transport device of Claim 1 or 2, wherein the aforementioned transfer mechanism further has a sliding part, The sliding part causes the holding part to slide and move in a horizontal direction, In the maintenance mode, when the control unit receives an action command from the operation terminal and the transfer mechanism, and the lifting height is within the interference height range, in addition to using the rotating unit to perform the rotating action of the holding unit In addition, it is also prohibited to use the sliding portion to perform the sliding movement of the holding portion.