Stocker

Abstract

This stocker comprises: a stacker crane; a first door that, in a closed state, closes a passage between a maintenance area and a storage area; a second door that, in a closed state, prohibits movement of a worker between an external space and the maintenance area; a first opening and closing sensor that detects opening and closing of the first door; a second opening and closing sensor that detects opening and closing of the second door; and a control unit. The control unit controls the stacker crane so that the stacker crane moves between the storage area and the maintenance area when an open state of the first door is detected by the first opening and closing sensor and the closed state of the second door is detected by the second opening and closing sensor; locks the second door while the open state of the first door is being detected by the first opening and closing sensor; and unlocks the second door when the closed state of the first door is detected by the first opening and closing sensor.

Description

Stock rack

[0001] The present disclosure relates to a stock rack.

[0002] Conventionally, there has been known a facility including a shelf having a plurality of storage sections for storing articles and a stacker crane for conveying the articles. In the facility described in Patent Document 1, the stacker crane can move from a conveying movement section to a retracting movement section. Maintenance work is performed on the stacker crane that has moved to the retracting stop position in the retracting movement section. The scaffold is movable between a boarding position located within the mast movement locus and a retracting position retracted laterally from the mast movement locus.

[0003] Japanese Patent Application Laid-Open No. 2017-088360

[0004] In the above-described conventional technology, a partition wall is provided between the conveying area and the retracting area, and an opening through which the stacker crane can pass is formed in the partition wall. The partition wall is provided with a door body that can open and close the opening. Patent Document 1 only describes that the internal area is divided into a conveying area and a retracting area by closing the door body with respect to the opening and closing of the door body. When an operator enters the retracting area to perform maintenance work, it is unclear how safety is ensured, and separate measures are required to ensure the safety of the operator.

[0005] The present disclosure describes a stock rack that can perform maintenance of a stacker crane while ensuring the safety of an operator.

[0006] [1] A stacker according to one aspect of the present disclosure includes a storage area for storing a plurality of articles, separated from the external space by a first wall, a maintenance area separated from the external space by a second wall and arranged side by side at the end of the storage area, a stacker crane capable of traveling in a travel space that crosses the storage area and the maintenance area, a first door positioned at the interface between the storage area and the maintenance area and, when closed, blocks the passage between the maintenance area and the storage area, a second door provided on the second wall and, when closed, prohibits the movement of workers between the external space and the maintenance area, and a second door for detecting the opening and closing of the first door. The system comprises an opening / closing sensor, a second opening / closing sensor for detecting the opening and closing of the second door, and a control unit for controlling the operation of the stacker crane and the switching operation of locking and unlocking the first and second doors. The control unit controls the stacker crane to move between the storage area and the maintenance area when the first opening / closing sensor detects that the first door is open and the second opening / closing sensor detects that the second door is closed. The control unit locks the second door while the first opening / closing sensor detects that the first door is open, and unlocks the second door when the first opening / closing sensor detects that the first door is closed.

[0007] According to the stocker in [1], the stacker crane moves between the storage area and the maintenance area when the first door is open and the second door is closed. Therefore, workers cannot enter the maintenance area while the stacker crane is moving (because they cannot open the second door). When the stacker crane stops in the maintenance area and the first door is closed, workers can open the second door and enter the maintenance area. In other words, the locking and unlocking of the second door, which affects whether workers can move (whether they can enter the maintenance area), is switched in conjunction with the state (position) of the first door, which affects whether the stacker crane can move. Therefore, workers will not come into contact with the stacker crane while it is moving. This ensures the safety of workers while allowing them to perform maintenance on the stacker crane in the maintenance area. Furthermore, since the first door, when closed, blocks the passage between the maintenance area and the storage area, there is no risk of workers entering the storage area for maintenance work and coming into contact with goods, and there is no need to take out the goods stored in the storage area.

[0008] [2] In the stocker described in [1] above, the storage area may be equipped with a purging device for injecting an inert gas into the articles, and the first door may be provided to prevent the movement of the inert gas between the storage area and the maintenance area. In this case, a decrease in the oxygen concentration in the maintenance area can be prevented at the start of maintenance work or during maintenance work. Therefore, the injection of inert gas into the articles can be continued without any problems.

[0009] [3] In the stacker described in [1] or [2] above, the second door is provided to open and close an opening in the side wall of the second wall body that is parallel to the direction of travel of the stacker crane, and the first door may be positioned to separate the opening from the travel space when it is open. When the stacker crane enters the maintenance area while traveling, even if a worker is in the maintenance area, the worker will be prevented from entering the travel space by the open first door. Thus, worker safety is further ensured. A configuration that enhances safety can be realized by arranging the first and second doors. No other safety devices are required.

[0010] [4] In any one of the stockers described in [1] to [3] above, when the stacker crane is stopped at a predetermined maintenance position within the maintenance area, the maintenance area may have a workspace that allows workers to perform maintenance work on either the side closer to the storage area or the side further away from the storage area in the direction of travel of the stacker crane, as well as on both sides of the travel space. In this case, the workability in the maintenance area is improved.

[0011] [5] In any one of the stackers described in [1] to [4] above, the second door is provided to open and close a side opening in the side wall portion of the second wall body parallel to the direction of travel of the stacker crane, and the end wall portion of the second wall body perpendicular to the direction of travel of the stacker crane is provided with a third door that opens and closes an end opening in the end wall portion, and the control unit may lock the third door while the first opening / closing sensor detects that the first door is open, and unlock the third door when the first opening / closing sensor detects that the first door is closed. In this case, when the stacker crane stops in the maintenance area and the first door is closed, the worker can open the third door and enter the maintenance area or access the front of the stacker crane. Therefore, the worker will not come into contact with the stacker crane while it is in motion. The worker can easily and safely access the front of the stacker crane.

[0012] According to this disclosure, workers can perform maintenance on the stacker crane in the maintenance area while ensuring their safety.

[0013] Figure 1 is a front view showing a stocker according to one embodiment of the present disclosure. Figure 2 is a perspective view showing a stacker crane provided in the stocker of Figure 1. Figure 3 is a block diagram showing the schematic configuration of the operating device, controller, stacker crane and each door. Figure 4 is a front view of the maintenance area. Figure 5 is a cross-sectional view of the maintenance area. Figure 6 is a diagram showing some examples of maintenance work positions within the maintenance area. Figure 7 is a perspective view showing the crane position sensor. Figure 8 is a diagram showing the state immediately after the stacker crane arrives in the maintenance area for maintenance work. Figure 9 is a diagram following Figure 8 showing the state of a worker entering the maintenance area. Figure 10 is a diagram following Figure 9 showing the state of a worker exiting the maintenance area. Figure 11 is a diagram following Figure 10 showing the state of the stacker crane returning to the storage area. Figure 12 is a cross-sectional view showing another configuration example in the central maintenance area of ​​the stocker. Figure 13 is a cross-sectional view showing another configuration example (modified example) within the maintenance area.

[0014] Embodiments of this disclosure will be described below with reference to the drawings. In the description of the drawings, the same elements will be denoted by the same reference numerals, and redundant descriptions will be omitted.

[0015] As shown in Figure 1, the stocker 1 of this embodiment includes, for example, a left stocker 2 and a right stocker 3. The stocker 1 includes, for example, a plurality of stockers arranged in a predetermined direction. The stocker 1 may also consist of a single stocker. In the stocker 1, a stacker crane 7 travels inside each of the left stocker 2 and the right stocker 3. In the stocker 1, the stacker crane 7 transports goods between a plurality of shelves S provided in the storage area MA of each of the left stocker 2 and the right stocker 3 and an inbound / outbound port (not shown). The left stocker 2 and the right stocker 3 store, for example, goods that have been transported by the stacker crane 7. The goods are, for example, containers such as FOUPs (Front-Opening Unified Pods) that contain wafers processed in semiconductor manufacturing equipment or liquid crystal manufacturing equipment, and reticle pods that contain reticles used in semiconductor manufacturing equipment or liquid crystal manufacturing equipment. The stocker 1 of this embodiment is a stocker equipped with a nitrogen purging function, but this disclosure may also be applied to a stocker that does not have a purging function.

[0016] In Stocker 1, the left Stocker 2 and the right Stocker 3 are arranged in the direction of travel of the stacker crane 7. Inside Stocker 1, two stacker cranes 7 are installed in each of the left Stocker 2 and the right Stocker 3. The left Stocker 2 includes, for example, a pair of racks 4, a left first stacker crane 7A, and a left second stacker crane 7B. The right Stocker 3 includes, for example, a pair of racks 4, a right first stacker crane 7C, and a right second stacker crane 7D. The left Stocker 2 and the right Stocker 3 have similar configurations, except for differences in the size of the racks 4. Therefore, in the following description, the left Stocker 2 will be described, while the description of the right Stocker 3, which has a similar configuration, will be omitted. Also, "stacker crane" is sometimes simply referred to as "crane." For convenience, the direction of travel of each stacker crane 7 will be the X direction, the vertical direction will be the Z direction, and the horizontal direction perpendicular to the X and Z directions will be the Y direction (width direction). The details of Stocker 1 will be described below.

[0017] The left stocker 2 is formed, for example, in the shape of a hollow rectangular parallelepiped. The left stocker 2 has a running rail 31 on which the left first crane 7A and the left second crane 7B travel, and an auxiliary rail 32 positioned opposite the running rail 31 in the Z direction, laid along the X direction. The left first crane 7A and the left second crane 7B travel (move) along the running rail 31 and the auxiliary rail 32. That is, the left first crane 7A and the left second crane 7B travel on a running path T that extends in the X direction. The left first crane 7A and the left second crane 7B are transport devices that transport goods between shelves S and the loading / unloading port and transfer goods to shelves S. Each rack 4 is provided along the X direction within the left stocker 2. A pair of racks 4 are arranged facing each other via the running rail 31. Each rack 4 is provided with multiple shelves S on which goods are stored. That is, each storage area MA stores multiple goods.

[0018] As shown in Figure 2, each crane 7 comprises a travel section 71, a mast 72, a transfer section 75, and an auxiliary travel section 79. The travel section 71 has a travel motor 78 and a lifting motor 82. The travel section 71 travels along a travel rail 31. The travel section 71 includes drive wheels that roll along the upper surface of the travel rail 31. The travel motor 78 is the power source for the travel drive wheels. The lifting motor 82 is the power source for the lifting platform 73. A housing (not shown) for housing the travel motor 78 and the lifting motor 82 may be provided. The mast 72 is erected in the Z direction on top of the travel section 71. The transfer section 75 transfers items to and from shelves S, and also transfers items to and from the loading / unloading ports. The auxiliary travel section 79 travels along an auxiliary rail 32. The auxiliary travel section 79 includes a pair of drive wheels that roll while sandwiching the auxiliary rail 32. The travel motor 78 is controlled by the controller 30 (control unit) (see Figure 3), causing each crane 7 to travel along the travel path T. The travel motor 78 is, for example, a servo motor, and can be controlled to any rotational speed by the controller 30. As a result, the controller 30 can control the travel motor 78 to make the crane 7 travel at any desired speed.

[0019] As shown in Figure 1, the stocker 1 has multiple maintenance areas for performing maintenance work on the crane 7 and other equipment, located along the extension of the travel path T. More specifically, the left stocker 2 includes a left maintenance area M1 and a central maintenance area M2, both located on either side of the rack 4 in the X direction. The right stocker 3 includes a central maintenance area M2 and a right maintenance area M3, both located on either side of the rack 4 in the X direction. Workers can perform maintenance on the crane 7 in each maintenance area. The maintenance areas are also called "maintenance docks".

[0020] Each of the left maintenance area M1, the central maintenance area M2, and the right maintenance area M3 can accommodate one of the cranes 7. In the left stocker 2, the left first crane 7A can be moved on the running rail 31 and housed in the left maintenance area M1, and the left second crane 7B can be moved on the running rail 31 and housed in the central maintenance area M2. In the right stocker 3, the right first crane 7C can be moved on the running rail 31 and housed in the central maintenance area M2, and the right second crane 7D can be moved on the running rail 31 and housed in the right maintenance area M3. Thus, the central maintenance area M2 is shared by the left stocker 2 and the right stocker 3. The left second crane 7B can enter the central maintenance area M2 from one side (the left side as shown in Figure 1), and the right first crane 7C can enter from the other side (the right side as shown in Figure 1). The central maintenance area M2 can accommodate either the left second crane 7B or the right first crane 7C. Therefore, the running rails 31 and auxiliary rails 32 of the left stocker 2 and the running rails 31 and auxiliary rails 32 of the right stocker 3 are connected in a straight line. The central maintenance area M2 can also accommodate both the left second crane 7B and the right first crane 7C (two units).

[0021] Each crane 7 is capable of traveling in a travel space C (see Figures 5 and 12) that traverses either storage area MA and the maintenance area adjacent to the storage area MA on one side in the X direction. For example, as shown in Figure 5, the left first crane 7A is capable of traveling in a travel space C that traverses the storage area MA and the left maintenance area M1 of the left stocker 2. Stoppers are provided at the travel ends of the cranes 7, but in this embodiment, stoppers (not shown) are provided only at the ends of the stocker 1, i.e., only at the ends of the left maintenance area M1 and the right maintenance area M3. This allows the left first crane 7A and the right second crane 7D to enter the maintenance area without human intervention. When we say that the travel space C "traverses" the storage area MA and the maintenance area adjacent to the storage area MA, we mean that the travel space C "extends in the X direction across both" the storage area MA and the maintenance area adjacent to the storage area MA.

[0022] Next, the configuration of the left maintenance area M1 and its surroundings in the left storage unit 2 will be described with reference to Figures 3 to 5. Note that the right maintenance area M3 has the same configuration as the left maintenance area M1, so its description will be omitted. In the central maintenance area M2, as shown in Figure 12, two travel spaces C for separate cranes 7 (specifically, the left second crane 7B and the right first crane 7C shown in Figure 1) are formed on both sides in the X direction, so the door configuration is different. However, the functional configuration of the first and second doors is the same as that shown in Figure 3, and the control during maintenance (in particular, the control of switching between locking and unlocking the doors) is the same as the control described later in the left maintenance area M1.

[0023] As shown in Figures 4 and 5, the storage area MA and the left maintenance area M1 are each surrounded by walls. The storage area MA is separated from the outside space by a pair of first walls 21 extending along the XZ plane. The left maintenance area M1, which is located at the end of the storage area MA in the X direction, is separated from the outside space by a second wall 22 that is C-shaped in plan view. Furthermore, a partition wall 25 extending along the YZ plane is provided at the interface 5 between the storage area MA and the left maintenance area M1 (see also Figure 7). The partition wall 25 separates the storage area MA and the left maintenance area M1. This configuration prevents worker A from easily accessing the items stored in the storage area MA.

[0024] These walls extend, for example, from the height of the interior floor surface FL to the height of the top surface of the left storage unit 2. In storage unit 1, the interior floor surface FL is lower than the floor surface F in the external space of storage unit 1 (the surface on which worker A walks). The height difference between the floor surface F and the interior floor surface FL can be appropriately set according to storage unit 1, but for example, it can be set to a height that allows worker A to ascend and descend without needing a ladder or stairs (for example, to waist height).

[0025] As shown in Figure 5, the second wall 22 has a pair of side wall portions 23 extending along the XZ plane (i.e., parallel to the direction of travel of the crane 7) and a single end wall portion 24 extending along the YZ plane (i.e., perpendicular to the direction of travel of the crane 7). The second wall 22, the partition wall 25, and the top wall define a vertically elongated rectangular left maintenance area M1.

[0026] As shown in Figures 4, 5, and 6, the left maintenance area M1 is provided with appropriate scaffolding, walkways, or ladders to allow access to the crane 7 from any position in the X, Y, and Z directions. For example, a pair of internal elevated floors 41, at the same height as the floor surface F, are provided on both sides of the travel space C in the Y direction, close to the end wall 24. In addition, a ladder 43 is installed on the side of the travel space C (a position that allows the crane 7 to travel without obstruction) close to the partition wall 25, to enable maintenance work at a height equivalent to the second floor. The ladder 43 may be fixed or movable. A horizontal upper walkway 42 is installed on the side of the travel space C (a position that allows the crane 7 to travel without obstruction) so as to connect to the top of the ladder 43. A pair of upper walkways 42 may be provided on both sides of the travel space C. The crane 7 may be movable within the left maintenance area M1. In that case, the position of the floor or walkway installed around the crane 7 and in the travel space may be moved as appropriate to suit the area to be maintained. Alternatively, the worker may maintain the crane 7 from the outside with the third door 63 open.

[0027] In addition to the above, although not shown in the diagram, a stepped, movable platform may be installed at the same height as the internal elevated floor 41 to allow worker A to access the central part of the crane 7 in the height direction. Alternatively, a temporary (rotatable) platform may be provided that is upright along the YZ plane when the crane 7 passes, but rotates around an axis extending in the X direction when the crane 7 is inside the left maintenance area M1, extending horizontally at the same height as the internal elevated floor 41.

[0028] As shown in Figure 5, the partition wall 25 has a rectangular interface opening 25e that opens in the portion overlapping with the travel space C to allow the crane 7 to pass through. The partition wall 25 is provided with a rectangular plate-shaped first door 61 that opens and closes this interface opening 25e. The first door 61 is located at the interface 5 between the storage area MA and the left maintenance area M1. When the first door 61 is closed, it blocks the passage for the crane 7 between the left maintenance area M1 and the storage area MA. When the first door 61 is open, it allows the crane 7 to move between the left maintenance area M1 and the storage area MA. The lower end of the first door 61 is spaced a predetermined distance from the internal floor surface FL to allow the passage of the crane 7's travel motor 78, etc., but the upper end of the first door 61 is close to the height of the top surface of the stocker 1. The length of the first door 61 in the Z direction may be part of the total height of the left maintenance area M1, or it may be shorter than the total height of the crane 7.

[0029] The storage area MA is equipped with a purge device 90 (see Figure 3) for injecting purge gas into the articles. The purge device 90 is controlled by a controller 30. The first door 61 is provided to prevent the movement of purge gas between the storage area MA and the left maintenance area M1. The movement of purge gas can be prevented solely by the size of the first door 61, or it can be prevented by creating a downward flow of air (air curtain) within the storage area MA using, for example, a downward-facing diffusion fan. In addition to the controller 30, a separate controller for controlling the purge device 90 may be provided. In this embodiment, nitrogen gas, which is an inert gas, is used as the purge gas, but it is not limited to this. Clean dry air or other gases besides inert gases may be used as the purge gas.

[0030] The side wall portion 23 of the second wall body 22 is provided with a rectangular side opening 23e that allows worker A to pass through. The side wall portion 23 is provided with a rectangular plate-shaped second door 62 that opens and closes the side opening 23e. The end wall portion 24 of the second wall body 22 is provided with a rectangular end opening 24e that allows worker A to pass through. The end wall portion 24 is provided with a rectangular plate-shaped third door 63 that opens and closes the end opening 24e. When these second doors 62 and third doors 63 are closed, worker A cannot move between the external space and the left maintenance area M1. When these second doors 62 and third doors 63 are open, worker A can move between the external space and the left maintenance area M1.

[0031] As shown in Figure 3, at least one of the interface opening 25e or the first door 61 is provided with a first opening / closing sensor 61b for detecting the opening and closing of the first door 61. The first door 61 is also provided with a first locking mechanism 61a, such as an electromagnetic lock, for locking the first door 61. Similarly, at least one of the side opening 23e or the second door 62 is provided with a second opening / closing sensor 62b for detecting the opening and closing of the second door 62. The second door 62 is also provided with a second locking mechanism 62a, such as an electromagnetic lock, for locking the second door 62. At least one of the end opening 24e or the third door 63 is provided with a third opening / closing sensor 63b for detecting the opening and closing of the third door 63. The third door 63 is also provided with a third locking mechanism 63a, such as an electromagnetic lock, for locking the third door 63.

[0032] Each of the first door 61, the second door 62, and the third door 63 has a hinge structure having an axis extending in the Z direction, and is rotatable around each hinge structure. The locking and unlocking operation of each of the first door 61, the second door 62, and the third door 63 is controlled by the controller 30. Each of the first door 61, the second door 62, and the third door 63 is locked when the closed state is detected by the respective opening / closing sensors. The first door 61 opens automatically when unlocked. On the other hand, each of the second door 62 and the third door 63 can be opened by worker A while unlocked. The first door 61 can be kept in the open state. On the other hand, each of the second door 62 and the third door 63, for example in a half-open state, is not kept in the open state and is always biased in the closing direction.

[0033] During normal transport by each crane 7, the first door 61 is closed, and the second door 62 and the third door 63 are also closed.

[0034] Here, the configuration related to the movement control of the crane 7 will be described. As shown in Figure 7, the left stocker 2 is equipped with a cable device 8 for supplying power to the left first crane 7A. The cable device 8 has a cable section 10 connected to the travel section 71 of the left first crane 7A. The left stocker 2 similarly has a cable device and cable section for the left second crane 7B. The cable section 10 has a cable section 10 for supplying power to the crane 7 and a guide roller 9 that supports the lifted portion of the cable section 10. The cable section 10 has a power cable 11 and a protective guide member 15. The power cable 11 is connected to the crane 7 and also to a power supply unit (not shown) in the left stocker 2. As a result, the crane 7 is powered from the power supply unit via the power cable 11.

[0035] The left stocker 2 of this embodiment is configured to automatically pull out (i.e., move) the crane 7 into the maintenance area when performing maintenance work on the crane 7. Multiple sensors detect the position of the crane 7, and the speed of the crane 7 is controlled in stages, resulting in the crane 7 being pulled out (moved) quickly. The configuration related to the travel control when the crane is pulled out will be described below.

[0036] As shown in Figures 3 and 7, the left stocker 2 is equipped with a crane position sensor 6 that detects when the left first crane 7A reaches the position where it has entered the left maintenance area M1. The crane position sensor 6 is provided at an appropriate position, for example, slightly inside the storage area MA from the boundary surface 5. The crane position sensor 6 is provided to correspond to (detect the cable portion 10) for supplying power to the crane 7. The crane position sensor 6 includes a switch portion 6a that becomes submerged when a specific portion (the portion to be detected) of the cable portion 10 is placed on it, and detects the presence of the specific portion. When the crane 7 is in normal operation, etc., and is located inside the storage area MA, the crane position sensor 6 continues to detect the absence of the specific portion. In this case, the specific portion of the cable portion 10 moves away from the crane position sensor 6, the switch portion 6a protrudes due to a biasing force such as an internal spring, and the crane position sensor 6 detects the absence of the specific portion. When the crane 7 reaches the position where it has entered the left maintenance area M1, the crane position sensor 6 detects the presence of the specific portion. The crane position sensor 6 can detect whether a specific part is located at the installation location of the crane position sensor 6, and can also detect whether the crane 7 is located at the entry position.

[0037] As shown in Figure 3, each crane 7 is controlled by the controller 30, for example, by an operator operating the control device 50, to move along the travel path T and enter one of the maintenance areas. In the stocker 1, the movement of the crane 7 to the maintenance area is performed automatically by pressing and holding the button on the control device 50.

[0038] As shown in Figure 3, the operating device 50 has an operating unit 51, a display unit 52, and a communication unit 53. The operating device 50 may be a terminal such as a tablet so that the operator can easily operate the crane 7. The operating unit 51 is, for example, a touch panel provided on the display unit 52. The display unit 52 is, for example, a liquid crystal display. The communication unit 53 can communicate information with the controller 30 by wireless or wired communication. The controller 30, which is a higher-level controller, may be provided in each maintenance area, for example, or mounted on the travel unit 71 of the crane 7. The controller 30 is an electronic control unit composed of a CPU (processor), ROM, RAM, etc. The controller 30 controls each part of the crane 7, including the travel motor 78.

[0039] When performing maintenance work on crane 7, the worker stops stocker 1. For example, all of the left crane 1A, left crane 2B, right crane 1C, and right crane 2D are stopped. Subsequently, one of the cranes 7 is moved to the corresponding maintenance area.

[0040] The following explanation will use the example of moving the left first crane 7A to the left maintenance area M1. The operator presses the control unit 51 labeled "Move to maintenance dock" on the display unit 52 of the control unit 50, which is connected to the left first crane 7A. Alternatively, the control unit 50 may be configured to allow the operator to select the crane 7 to be moved using the control unit 50.

[0041] When the operating unit 51 is pressed with a finger, the controller 30 checks the status of the first door 61, the second door 62, and the third door 63 (whether they are open or closed). When the first open / close sensor 61b confirms that the first door 61 is open, and the second open / close sensor 62b and the third open / close sensor 63b detect that both the second door 62 and the third door 63 are closed, the controller 30 controls the left first crane 7A to move between the storage area MA and the left maintenance area M1. First, the controller 30 controls the first locking unit 61a to unlock the first door 61. Next, when the controller 30 confirms that the first door 61 is open, it controls the travel motor 78 to move the left first crane 7A. The first open / close sensor 61b detects the state when the movement of the first door 61 is complete (a state that allows the movement of the crane 7 between the left maintenance area M1 and the storage area MA) as the open state.

[0042] Next, the controller 30 stops the left first crane 7A at a predetermined maintenance position within the left maintenance area M1. The stopping control of the left first crane 7A within the left maintenance area M1 is performed using, for example, a known mechanism having a dog and a sensor. While the first opening / closing sensor 61b detects that the first door 61 is open, the controller 30 keeps both the second door 62 and the third door 63 locked at all times.

[0043] Subsequently, as shown in Figure 8, the controller 30 controls the first locking unit 61a to lock the first door 61. At the point shown in Figure 8, the first door 61, the second door 62, and the third door 63 are all closed. Then, any worker A operates the operating device 50 and requests the unlocking of either or both of the second door 62 and the third door 63. The first opening / closing sensor 61b detects the state in which the first door 61 has completed its movement (blocking the passage for the crane 7 between the left maintenance area M1 and the storage area MA) as the closed state.

[0044] As shown in FIG. 9, when the closed state of the first door 61 is detected by the first opening / closing sensor 61b, the controller 30 unlocks both the second door 62 and the third door 63 in response to a request signal from the operation device 50. Then, maintenance work is carried out in the left maintenance area M1 by one or more operators A. As shown in FIG. 9, during the maintenance work, the second door 62 and the third door 63 are maintained in an open state, for example.

[0045] In the stocker 1 provided with the purge device 90, based on the value of the oxygen concentration sensor provided at an appropriate position in the storage area MA, the controller 30 determines whether to unlock both the second door 62 and the third door 63. For example, only when the oxygen concentration is equal to or higher than a threshold value (19.5%), the controller 30 unlocks both the second door 62 and the third door 63 in response to a request signal from the operation device 50.

[0046] Maintenance work is then carried out within the left maintenance area M1. As shown in Figure 6, when the left first crane 7A is stopped at a predetermined maintenance position in the left maintenance area M1 (approximately in the center of the left maintenance area M1), a workspace is formed in the left maintenance area M1 that allows worker A to perform maintenance work on both the side closer to the storage area MA and the side further away from the storage area MA in the direction of travel of the left first crane 7A (X direction). In Figure 9, although worker A is not shown, a workspace is also formed in the left maintenance area M1 that allows worker A to perform maintenance work on both sides in the Y direction of the left first crane 7A. Note that during maintenance work, the first door 61 is closed (blocking the passage between the left maintenance area M1 and the storage area MA), so workers in the maintenance area cannot access the storage area MA (the items stored in the storage area MA). Depending on the position of the left first crane 7A (or the equipment within the left maintenance area M1), a workspace that allows worker A to perform maintenance work may be formed only on either the side closer to the storage area MA or the side further away from the storage area MA in the direction of travel (X direction). If maintenance is performed with the third door 63 open, the workspace on the far side does not need to be secured within the left maintenance area M1.

[0047] When the maintenance work is completed, all workers A exit the storage area MA (see Figure 10). When the workers input information such as "work completed" to the control device 50 from outside the maintenance area, and the second opening / closing sensor 62b and the third opening / closing sensor 63b detect that the second door 62 and the third door 63 are closed, the controller 30 controls the first locking unit 61a to unlock the first door 61. Next, when the controller 30 confirms that the first door 61 is open, it controls the travel motor 78 to move the left first crane 7A.

[0048] Incidentally, at this time, as shown in FIG. 11, the first door 61 is positioned so as to separate (or block) an access path along the Y direction connecting the side opening 23e and the running space C in the open state. With such an arrangement of the first door 61 and the side opening 23e, the operator A cannot enter the running space C by walking straight from the side opening 23e.

[0049] According to the stocker of the present embodiment, the stacker crane moves between the storage area and the maintenance area when the first door is open and the second door is closed. Therefore, the operator cannot enter the maintenance area while the stacker crane is running (because the second door cannot be opened). When the stacker crane stops in the maintenance area and the first door is closed, the operator can open the second door and enter the maintenance area. That is, in conjunction with the state (position) of the first door related to the running ability of the stacker crane, the locking and unlocking of the second door related to the movement ability of the operator (the ability to enter the maintenance area) are switched. Thus, the operator does not come into contact with the running stacker crane. Thereby, while ensuring the safety of the operator, the operator can perform maintenance on the stacker crane in the maintenance area. Since there is no risk that the operator will enter the storage area and touch the articles for maintenance work, there is no need to dispense the articles stored in the storage area. The maintenance work of the present embodiment results in a great saving of time compared to the case of dispensing the previous articles.

[0050] The first door is provided so as to prevent the movement of an inert gas (such as nitrogen gas) between the storage area and the maintenance area. Thereby, it is possible to prevent a decrease in the oxygen concentration in the maintenance area at the start or during the maintenance work. The injection of the inert gas into the articles can continue without hindrance.

[0051] The first door, when open, is positioned to separate (or block) the access path connecting the opening and the travel space. When the stacker crane enters the maintenance area while traveling, even if a worker is inside the maintenance area, the worker will be prevented from entering the travel space by the open first door. Therefore, worker safety is further ensured. The arrangement of the first and second doors enables a configuration that enhances safety. No other safety devices are required.

[0052] When the stacker crane is stopped at a designated maintenance position within the maintenance area, the maintenance area provides workspace that allows workers to perform maintenance tasks on both the side closer to the storage area and the side further away from the storage area in the direction of the stacker crane's travel. This improves the work efficiency within the maintenance area.

[0053] The control unit locks the third door while the first door is detected as open by the first door open / close sensor, and unlocks the third door when the first door is detected as closed by the first door open / close sensor. As a result, when the stacker crane stops within the maintenance area and the first door is closed, the worker can open the third door and enter the maintenance area. Therefore, the worker will not come into contact with the stacker crane while it is in motion. The worker can easily and safely access the front of the stacker crane.

[0054] Although embodiments of the present disclosure have been described above, the present invention is not limited to the above embodiments. For example, the purging device 90 may be omitted.

[0055] As shown in Figure 12, in the central maintenance area M2, a pair of first doors 66 for opening and closing the interface opening 26e may be provided on a pair of partition walls 26, and a second door 67 for opening and closing the central side opening 27e may be provided on the central side wall 27. In this case as well, the controller 30 will perform the same control as described above.

[0056] As shown in Figure 13, a third wall 29 connecting the first door 61 and the second wall 22 may be provided in the work space when the first door 61 is open. In this case, even if the second door 62 opens due to a malfunction or the like when the first door 61 is open, i.e., when the left first crane 7A is in motion, worker A cannot access the travel space C and the storage area MA, thus further improving the safety of worker A and the stored items. In the embodiment in which the third wall 29 is provided, worker A can perform maintenance on the side of the crane 7 by moving on (for example, two) movable maintenance steps 47A and 47B laid in the travel space C (see the dashed line path P in Figure 13). Note that the maintenance step 47B, which is located near the crane 7 (near the end face opening 24e) in the travel direction (X direction), is located above the transfer section 75, etc., in the illustrated state and does not interfere with the crane 7.

[0057] In this embodiment, the first door 61, the second door 62, and the third door 63 are shown as single-leaf doors, but are not limited to this. They may also be double-leaf doors, sliding doors, folding doors, etc.

[0058] During normal transport by each crane 7, the first door 61 may be in the open position. In this case, during maintenance, after the crane moves to the maintenance area, and before the second door 62 and the third door 63 are unlocked, air is supplied to increase the oxygen concentration in the maintenance area.

[0059] The two cranes have means (such as appropriate sensors) to determine whether or not they are located in the central maintenance area M2 (see Figure 12). If one crane is located in the maintenance area M2, the other crane is controlled to prevent it from entering the maintenance area M2.

[0060] To control the humidity in the storage area, an inert gas may be injected throughout the storage area. In this case, a device is provided to supply air to the maintenance area during maintenance, and the second and third doors are unlocked only after the oxygen concentration in the maintenance area has been ensured.

[0061] 1...Storage unit, 5...Interface, 21...First wall, 22...Second wall, 23...Side wall, 23e...Side opening, 24...End wall, 24e...End face opening, 25...Partition wall, 25e...Interface opening, 30...Controller (control unit), 61...First door, 61b...First opening / closing sensor, 62...Second door, 62b...Second opening / closing sensor, 63...Third door, 63b...Third opening / closing sensor, 90...Purge device, C...Travel space, M1...Left maintenance area, M2...Central maintenance area, M3...Right maintenance area, MA...Storage area.

Claims

1. A storage area for accommodating multiple articles, separated from the external space by a first wall; a maintenance area separated from the external space by a second wall and arranged side-by-side at the end of the storage area; a stacker crane capable of traveling in a travel space traversing the storage area and the maintenance area; a first door positioned at the boundary between the storage area and the maintenance area, which, when closed, blocks the passage between the maintenance area and the storage area; a second door provided in the second wall, which, when closed, prohibits the movement of workers between the external space and the maintenance area; a first open / close sensor for detecting the opening and closing of the first door; a second open / close sensor for detecting the opening and closing of the second door; and a control unit for controlling the operation of the stacker crane and the switching operation of locking and unlocking the first and second doors, wherein the control unit controls the stacker crane to move between the storage area and the maintenance area when the open state of the first door is detected by the first open / close sensor and the closed state of the second door is detected by the second open / close sensor. A storage device that locks the second door while the first door is detected to be open by the first opening / closing sensor, and unlocks the second door when the first door is detected to be closed by the first opening / closing sensor.

2. The storage area is equipped with a purging device for injecting an inert gas into the articles, and the first door is provided to prevent the movement of the inert gas between the storage area and the maintenance area, as described in claim 1.

3. The stocker according to claim 1 or 2, wherein the second door is provided to open and close an opening in the side wall portion of the second wall body parallel to the travel direction of the stacker crane, and the first door, when in the open state, is positioned to separate an access path connecting the opening and the travel space.

4. The storage crane according to claim 1 or 2, wherein when the stacker crane is stopped at a predetermined maintenance position within the maintenance area, the maintenance area has a workspace formed on either the side closer to the storage area or the side further from the storage area in the direction of travel of the stacker crane, and on both sides of the travel space, enabling maintenance work by an operator.

5. The stocker according to claim 1 or 2, wherein the second door is provided to open and close a side opening in the side wall portion of the second wall body parallel to the direction of travel of the stacker crane, and a third door is provided in the end wall portion of the second wall body perpendicular to the direction of travel of the stacker crane, and the control unit locks the third door while the open state of the first door is detected by the first opening / closing sensor, and unlocks the third door when the closed state of the first door is detected by the first opening / closing sensor.

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