Item loading stand

Abstract

The present invention prevents two frontages from being simultaneously opened on lower sides thereof. A rack (3) comprises a shelf part (31), a first frontage (33a), a second frontage (33b), and a shutter (41). On the shelf part (31), an article (A) can be placed at a position apart upward from a floor surface (F). The first frontage (33a) and the second frontage (33b) are disposed opposite each other in the Y direction for allowing access to the shelf part (31). The shutter (41) opens one of the two frontages and closes the other. The shutter (41) passes through a space SP between the floor surface (F) and the shelf part (31) when moving for switching the frontage to be closed.

Description

[Technical Field]

[0001] The present invention relates to an article placement platform for placing articles on, and more particularly to an article placement platform having two openings for transferring articles and equipped with a safety device that closes one opening when the other opening is used to transfer an article. [Background technology]

[0002] It is known that a conveying device such as a stacker crane places items on a platform, and a worker performs a predetermined task (e.g., picking) on ​​the items placed on the platform. The platform used for this purpose has an opening for transferring items from the conveying device to the platform, and an opening for the worker to perform the task on the items placed on the platform. Note that these two openings are arranged to face each other.

[0003] In addition, the above-mentioned loading platform is provided with a safety device having a shutter that closes the opening on the worker's side when an item is transferred from the conveying device to the loading platform, and closes the opening on the conveying device side when the worker works on the item on the loading platform (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 11-165811 Summary of the Invention [Problem to be solved by the invention]

[0005] When switching the closing opening, the shutter of a conventional safety device moves from the opening opening to the closing opening, passing over the top of the platform. Therefore, for example, if the shutter stops due to an abnormality or the like before reaching the closing opening, there is a possibility that both the opening where the worker works and the opening where the conveying device transfers the item will be open on the lower side. If both openings are open on the lower side, the worker can access the platform while the conveying device is transferring the item, so it is preferable to avoid a situation where both openings are open on the lower side.

[0006] An object of the present invention is to prevent an article placement table having two opposing openings from having the lower sides of the two openings open at the same time. [Means for solving the problem]

[0007] Below, several aspects will be described as means for solving the problems. These aspects can be arbitrarily combined as necessary. An article storage platform according to one aspect of the present invention comprises a storage section, two openings, a shutter, and a drive unit. The storage section is capable of storing articles at a position above the floor surface. The two openings are arranged opposite each other in a direction perpendicular to the width direction of the storage section and are for accessing the storage section. The shutter opens one of the two openings and closes the other. When the shutter moves to switch the opening to be closed, it passes through the space between the floor surface and the storage section.

[0008] In the above-described article platform, when the shutter moves to switch the opening to be closed, it passes through the space between the floor and the platform and moves from one opening to the other. As a result, even if the shutter stops midway through its movement from one opening to the other, the lower side of at least one of the two openings remains closed by the shutter, preventing the lower sides of both openings from being simultaneously open. Furthermore, because the shutter switches the opening by passing through the space between the platform and the floor, the opening cannot be switched if an automated guided vehicle and / or person is present in the space between the platform and the floor. As a result, it is possible to determine whether or not to switch the opening without using a sensor or other device to detect whether an automated guided vehicle and / or person is present in the space between the platform and the floor.

[0009] The article mounting table may further include a drive unit. The drive unit may have a pair of drive members. The pair of drive members are arranged at a distance wider than the width of the mounting table and move the shutter while supporting both ends of the shutter. Each drive member may have four rotating members and an endless member. The four rotating members are arranged at the four corners of the shutter's movement path. The endless member is hung on the four rotating members and supports one end of the shutter. This allows the shutter to be placed on the article mounting table with a simple configuration of rotating members and endless members.

[0010] The drive unit may move the shutter by rotating one of the four rotary members of the pair of drive members, thereby enabling the shutter to be driven with a simple configuration that rotates one rotary member.

[0011] The article platform may further include two sensors that detect the shutter. The two sensors are arranged side by side along the movement path of the shutter. In this case, the shutter may continue to move if both sensors detect the shutter, and may stop if either sensor does not detect the shutter. This allows the shutter to be moved appropriately with a simple configuration that includes only two sensors.

[0012] The article platform may further include three sensors for detecting the shutter. The three sensors are arranged in a line along the movement path of the shutter. This allows for more precise movement of the shutter.

[0013] The shutter may have a length equivalent to the sum of the height of the opening and the length in a direction perpendicular to the width direction of the mounting section. The sensor may also be located near one of the two openings. Furthermore, the direction of movement of the shutter may determine which of the two sensors stops the shutter if it is not detected. In this way, by switching the roles of the two sensors depending on the direction of movement of the shutter, the shutter can be moved appropriately with a small number of sensors.

[0014] The shutter may have a length equivalent to the sum of the height of the opening and the length in a direction perpendicular to the width direction of the mounting section. Alternatively, three sensors may be disposed near one of the openings. Furthermore, whether the shutter movement speed is reduced or the shutter is stopped when the shutter is no longer detected by any of the three sensors may be determined based on the shutter movement direction. In this way, by switching the roles of the three sensors depending on the shutter movement direction, more advanced shutter movement can be achieved.

[0015] If the shutter status cannot be determined by the sensor, the shutter status may be determined by moving the shutter in a circular motion and having the sensor detect the shutter. This makes it possible to determine the shutter status by the above operation even if the shutter status cannot be determined due to recovery from an abnormal state or startup of the device. [Effects of the Invention]

[0016] This prevents the lower sides of the two openings from being open at the same time. [Brief explanation of the drawings]

[0017] [Figure 1] Floor plan of an automated warehouse. [Figure 2] View of the safety device from the extension direction of the rack. [Figure 3] View of the safety device from the first opening side. [Figure 4] FIG. 1 is a diagram showing the control configuration of an automated warehouse. [Figure 5A] FIG. 10 is a diagram showing a state in which the first opening is closed by the shutter. [Figure 5B] FIG. 10 is a diagram showing a state when the shutter is in the middle of moving toward the second opening. [Figure 5C] FIG. 10 is a diagram showing the state in which the second opening is closed by the shutter. [Figure 6A] FIG. 10 is a diagram showing the state in which the second opening is closed by the shutter. [Figure 6B] FIG. 10 is a diagram showing a state when the shutter is in the middle of moving toward the first opening. [Figure 6C] FIG. 10 is a diagram showing a state in which the first opening is closed by the shutter. DETAILED DESCRIPTION OF THE INVENTION

[0018] 1. First embodiment (1) Automated warehouse An automated warehouse 1 having an article placement table according to the present disclosure will be described using Figures 1 to 3. Figure 1 is a plan view of the automated warehouse 1. Figure 2 is a view of the safety device 4 as seen from the extension direction of the rack 3. Figure 3 is a view of the safety device 4 as seen from the first entrance 33a side. In the following description, the left-right direction in Figure 1 is defined as the X direction, the up-down direction in Figure 1 is defined as the Y direction, and the direction perpendicular to the plane of Figure 1 (i.e., the height direction) is defined as the Z direction. The automated warehouse 1 is a facility installed in a logistics base such as a factory or warehouse, and is capable of storing, storing, and retrieving an article A. The article A that can be stored in the automated warehouse 1 is, for example, the luggage itself, luggage placed on a pallet, etc. The automated warehouse 1 includes a rack 3 (an example of an article placement table) and a conveying device 5.

[0019] The rack 3 is a facility for storing the item A. The rack 3 has a plurality of placement sections 31 on which the item A is placed. The plurality of placement sections 31 are arranged along the X direction. The placement sections 31 are fixed at positions a predetermined distance above the floor surface F of the first frame FL1 extending in the Z direction, and the item A can be placed at a distant position above the floor surface F. The rack 3 may further have multiple shelves in the Z direction (height direction) for placing the item A.

[0020] The article A placed on the placement section 31 has various sizes. For example, the length of the article A may be longer or shorter than the length of the placement section 31 in the Y direction.

[0021] The rack 3 is provided with two openings, a first opening 33a and a second opening 33b, for accessing each mounting section 31. The first opening 33a is provided on the side of the mounting section 31 facing the conveying device 5. The first opening 33a is used when transferring an article A from the conveying device 5 to the mounting section 31 or from the mounting section 31 to the conveying device 5.

[0022] The second opening 33b is provided opposite the first opening 33a in the Y direction, with the placement unit 31 in between. In other words, the second opening 33b is provided on the opposite side of the placement unit 31 from the side facing the conveying device 5. The second opening 33b is used when the worker W accesses the placement unit 31. Specifically, the worker W can enter the placement unit 31 from an external workbench 35 through the second opening 33b. The worker W can also move from the placement unit 31 to the external workbench 35 through the second opening 33b. This allows the worker W to, for example, enter the placement unit 31 and perform a predetermined task on the item A placed on the placement unit 31. For example, the worker W can move the item A from the placement unit 31 to the outside. The worker W can also place the item A on the placement unit 31 from the outside.

[0023] Furthermore, a worker W present outside the rack 3 can use the second opening 33b to pick up an item A placed on the placement section 31 (so-called "back picking").

[0024] The second opening 33b may be large enough for the worker W to pass through, or large enough for a vehicle such as a forklift to pass through. In the latter case, not only the worker W but also the vehicle can enter the placement section 31.

[0025] The rack 3 is also provided with a safety device 4 for keeping the first opening 33a and the second opening 33b, whichever is in use, open while closing the unused opening. The specific configuration of the safety device 4 will be described in detail later.

[0026] The conveying device 5 is a device that conveys the article A between the multiple placement sections 31, the receiving station (not shown), and / or the outgoing station (not shown). Specifically, the conveying device 5 conveys the article A by moving along a guide rail 51 provided along the X direction (i.e., the arrangement direction of the multiple placement sections 31). The conveying device 5 is, for example, a stacker crane.

[0027] The conveying device 5 has a transfer device 53. The transfer device 53 is a device for transferring item A between the conveying device 5 and the placement section 31, the storage station, or the delivery station. The transfer device 53 extends in the Y direction from the transfer device 53 through the first opening 33a to the placement section 31 while holding item A, and then releases its hold on item A, thereby transferring item A from the conveying device 5 to the placement section 31. On the other hand, the transfer device 53 extends from the transfer device 53 through the first opening 33a to the placement section 31, holds item A placed on the placement section 31, and then contracts from the placement section 31 to the transfer device 53 while holding item A, thereby transferring item A from the placement section 31 to the conveying device 5. Examples of such a transfer device 53 include a device having a slide fork that is extendable in the Y direction and on which item A can be placed, or a device that has a member for holding item A on an arm that is extendable in the Y direction.

[0028] 1 shows an example of the automated warehouse 1 in which one rack 3 and one conveying device 5 are arranged side by side in the Y direction, but the configuration of the automated warehouse 1 is not limited to this. In other examples of the automated warehouse 1, the above-mentioned racks 3 and conveying devices 5 may be arranged side by side in multiple alternating fashion in the Y direction.

[0029] (2)Safety device 2 and 3, the configuration of the safety device 4 provided on each mounting portion 31 of the rack 3 will be described. The safety device 4 includes a shutter 41 and a drive unit 43.

[0030] The shutter 41 opens one of the first opening 33a and the second opening 33b to allow access to the mounting section 31, and closes the other opening to prevent access to the mounting section 31. The shutter 41 has a shutter member 41a and a shutter support member 41b.

[0031] The shutter member 41a is a planar member having a predetermined width and length. The width of the shutter member 41a is set to be larger than the width (length in the X direction) of the placement portion of the placement section 31 where the article A is placed. On the other hand, the length (length in the Y direction and Z direction) of the shutter member 41a is set to be a length equivalent to the sum of the length (i.e., height) of the openings (first opening 33a, second opening 33b) in the Z direction and the length of the placement section 31 in the Y direction (direction perpendicular to the width direction). With these dimensions, when one end of the shutter member 41a in the length direction reaches the top of the opening, it can simultaneously cover the entire opening and the entire lower part of the placement section 31.

[0032] The length of the shutter member 41a does not need to have the above dimensions as long as it can ensure safety in the automated warehouse 1. For example, if the placement section 31 is long in the Y direction, the shutter member 41a does not necessarily need to be long enough to cover the entire opening and the entire lower part of the placement section 31.

[0033] The shutter support member 41b is a rod-shaped member for supporting the shutter member 41a. A plurality of shutter support members 41b are arranged in a line in the longitudinal direction of the shutter member 41a, and are fixed to the shutter member 41a except for both end portions. Both end portions of the shutter support member 41b are fixed to an endless member of the driving member. By fixing both end portions of the shutter support member 41b to the endless member, the shutter 41 (shutter member 41a) can move in accordance with the movement of the endless member of the driving member.

[0034] The drive unit 43 drives and moves the shutter 41. The drive unit 43 has a pair of drive members 43a, 43b. The pair of drive members 43a, 43b are arranged at a distance wider than the width of the placement portion of the placement section 31 for the article A. Specifically, the drive member 43a is arranged on the left side when viewed from the first opening 33a, and the drive member 43b is arranged on the right side. The pair of drive members 43a, 43b move the shutter 41 while supporting both ends of the shutter 41 in the width direction (both end portions of the shutter support member 41b).

[0035] Each of the pair of drive members 43a and 43b has four rotating members 431a and 431b and endless members 433a and 433b. The four rotating members 431a and 431b are arranged at the four corners of the movement path of the shutter 41. The rotating members 431a and 431b are, for example, sprockets or pulleys.

[0036] Specifically, two of the four rotating members 431a are arranged rotatably around the X axis at the bottom and end in the Y direction of the mounting unit 31 on the left side as viewed from the first opening 33a. The remaining two rotating members 431a are arranged rotatably around the X axis at the end in the Y direction of the second frame FL2 on the left side as viewed from the first opening 33a. The second frame FL2 is fixed to the first frame FL1 above the mounting unit 31 of the rack 3.

[0037] On the other hand, two of the four rotation members 431b are arranged rotatably around the X axis at the end in the Y direction of the lower part of the mounting unit 31 on the right side as viewed from the first opening 33a. The remaining two rotation members 431b are arranged rotatably around the X axis at the end in the Y direction of the second frame FL2 on the right side as viewed from the first opening 33a.

[0038] The endless member 433a is hooked onto four rotating members 431a arranged on the left side as viewed from the first opening 33a, and moves as the four rotating members 431a rotate around the X-axis. The endless member 433a also fixes the left end of the shutter support member 41b, and supports the shutter 41 on the left side.

[0039] The endless member 433b is hooked onto four rotating members 431b arranged on the right side as viewed from the first opening 33a, and moves as the four rotating members 431b rotate around the X-axis. The endless member 433b also fixes the right end of the shutter support member 41b, and supports the shutter 41 on the right side.

[0040] If the rotating members 431a and 431b are sprockets, the endless members 433a and 433b are, for example, chains. On the other hand, if the rotating members 431a and 431b are pulleys, the endless members 433a and 433b are, for example, endless belt members such as timing belts.

[0041] With the above configuration, by rotating the rotating members 431a, 431b around the X-axis, the shutter 41 supported by the endless members 433a, 433b can be moved across the first opening 33a, the space SP between the bottom of the mounting section 31 and the floor surface F, the second opening 33b, and the top of the second frame FL2.

[0042] The drive unit 43 further includes a drive supply unit 435. The drive supply unit 435 supplies a drive force to rotate one of the four rotation members 431a and one rotation member 431b that faces the rotation member 431a in the X direction. The drive supply unit 435 is configured with, for example, a motor and a drive conversion mechanism that converts the rotation of the motor into rotation of the rotation member about the X axis.

[0043] With the above configuration, the drive unit 43 can move the shutter 41 supported by the endless members 433a and 433b with a simple configuration in which the drive supply unit 435 rotates one of the four rotating members.

[0044] The safety device 4 further includes a first sensor 45a and a second sensor 45b. The first sensor 45a and the second sensor 45b are sensors that detect the shutter 41. The first sensor 45a and the second sensor 45b are, for example, photoelectric sensors that detect the shutter 41 when the shutter 41 blocks light.

[0045] The first sensor 45a and the second sensor 45b are arranged below the mounting section 31 and near the first opening 33a, side by side along the movement path of the shutter 41 in the space SP between the mounting section 31 and the floor surface F. Specifically, the first sensor 45a is arranged closer to the first opening 33a, and the second sensor 45b is arranged at a position away from the first opening 33a.

[0046] By arranging the first sensor 45a and the second sensor 45b side by side along the movement path of the shutter 41, it is possible to detect the movement direction and position of the shutter 41 based on which of the two sensors detects the shutter 41. A method for detecting the movement direction and position of the shutter 41 using the above two sensors will be described later.

[0047] (3) Controller The automated warehouse 1 further includes a controller 7. The controller 7 is a computer system equipped with a CPU, storage devices (RAM, ROM, etc.), and various interfaces, and controls each component of the automated warehouse 1. The control of each component of the automated warehouse 1 may be achieved by a program that is stored in the storage device of the controller 7 and is executable by the controller 7. Furthermore, some or all of the control of each component may be achieved by hardware that constitutes the controller 7. The control configuration of the automated warehouse 1 by the controller 7 will be explained below using FIG. 4. FIG. 4 is a diagram showing the control configuration of the automated warehouse 1.

[0048] The controller 7 controls the travel of the conveying device 5 and the transfer of the item A by the transfer device 53 based on commands from the upper controller 8. The upper controller 8 is a computer system that manages the item A in the automated warehouse 1.

[0049] The controller 7 controls the movement of the shutter 41 by controlling the drive supply unit 435 based on commands from the upper controller 8 and / or the operation unit 9. For example, when the upper controller 8 issues a command to transfer the article A from the conveying device 5 to the placement unit 31 or in the opposite direction, the controller 7 outputs a signal to the drive supply unit 435 to move the shutter 41 in a direction to open the first opening 33a and close the second opening 33b.

[0050] On the other hand, for example, when worker W performs a predetermined operation using the operation unit 9 (for example, pressing a button provided on the operation unit 9), the controller 7 determines that worker W will be working on the placement unit 31, and outputs a signal to the drive supply unit 435 to move the shutter 41 in a direction to open the second opening 33b and close the first opening 33a.

[0051] Furthermore, the controller 7 grasps the state of the shutter 41 based on the detection results of the shutter 41 by the first sensor 45a and the second sensor 45b, and outputs a signal to the drive supply unit 435 to control the movement of the shutter 41 based on the grasped state of the shutter 41.

[0052] (4) Operation of the automated warehouse (4-1) Transfer of goods The operation of the automated warehouse 1 having the above configuration will be described below. First, the operation of transferring the item A between the conveying device 5 and the loading section 31 will be described. For example, when the upper controller 8 issues a command to transfer the item A between the conveying device 5 and the loading section 31, the controller 7 moves the shutter 41 to close the second opening 33b and open the first opening 33a.

[0053] For example, if the first opening 33a is in a closed state as shown in Fig. 5A before the above command is issued, the controller 7 moves the shutter 41 from the first opening 33a to the second opening 33b in order to switch the opening to be closed to the second opening 33b. At this time, the controller 7 passes the shutter 41 through the space SP between the placement unit 31 and the floor surface F, and moves the shutter 41 to the second opening 33b. Fig. 5A is a diagram showing a state in which the first opening 33a is closed by the shutter 41.

[0054] As shown in FIG. 5A, when the shutter 41 closes the first opening 33a, the first sensor 45a closer to the first opening 33a detects the shutter 41, while the second sensor 45b closer to the second opening 33b does not detect the shutter 41.

[0055] When the shutter 41 starts moving and passes through the space SP between the placement unit 31 and the floor F, the shutter 41 is detected by both the first sensor 45a and the second sensor 45b. However, in this case, as shown in FIG. 5B, the second opening 33b is not completely closed by the shutter 41, and the first opening 33a is not completely open. Therefore, when the shutter 41 is detected by both the first sensor 45a and the second sensor 45b, the controller 7 determines that the shutter 41 is in the middle of moving toward the second opening 33b and continues moving the shutter 41 toward the second opening 33b. FIG. 5B is a diagram showing a state when the shutter 41 is in the middle of moving toward the second opening 33b.

[0056] As the shutter 41 moves further, the second sensor 45b, which is closer to the second opening 33b, detects the shutter 41, while the first sensor 45a, which is closer to the first opening 33a, no longer detects the shutter 41. In this case, as shown in FIG. 5C , the second opening 33b is closed by the shutter 41, and the first opening 33a is open. Therefore, when the state where the shutter 41 is detected by both the first sensor 45a and the second sensor 45b changes to a state where the second sensor 45b detects the shutter 41 but the first sensor 45a does not detect the shutter 41, the controller 7 determines that the shutter 41 has closed the second opening 33b and stops the movement of the shutter 41 toward the second opening 33b. FIG. 5C illustrates a state where the second opening 33b is closed by the shutter 41.

[0057] 5C, when the first opening 33a is open and the second opening 33b is closed, the conveying device 5 can extend the transfer device 53 to the mounting section 31 and transfer the article A between the mounting section 31. On the other hand, the worker W cannot enter the mounting section 31 because the second opening 33b is closed. In this way, the safety device 4 prevents the worker W from accessing the mounting section 31 while the conveying device 5 is accessing it, thereby ensuring safety.

[0058] Next, a description will be given of the operation when allowing the worker W to access the mounting section 31. For example, when the worker W presses a button or the like provided on the operation unit 9 to notify that the worker W wishes to access the mounting section 31, the controller 7 moves the shutter 41 to close the first opening 33a and open the second opening 33b.

[0059] For example, if the second opening 33b is closed as shown in Fig. 6A before the notification is given, the controller 7 moves the shutter 41 from the second opening 33b toward the first opening 33a to switch the opening to be closed to the first opening 33a. At this time, the controller 7 passes the shutter 41 through the space SP between the placement unit 31 and the floor surface F, and moves the shutter 41 to the first opening 33a. Fig. 6A is a diagram showing a state in which the second opening 33b is closed by the shutter 41.

[0060] As shown in FIG. 6A, when the shutter 41 closes the second opening 33b, the first sensor 45a closer to the first opening 33a does not detect the shutter 41, while the second sensor 45b closer to the second opening 33b detects the shutter 41.

[0061] When the shutter 41 starts moving and passes through the space SP between the placement unit 31 and the floor surface F, the shutter 41 is detected by both the first sensor 45a and the second sensor 45b. However, in this case, as shown in FIG. 6B, the second opening 33b is not completely closed by the shutter 41, and the first opening 33a is not completely open. In this case, the controller 7 determines that the shutter 41 is in the middle of moving toward the first opening 33a, and continues moving the shutter 41 toward the first opening 33a. FIG. 6B is a diagram showing a state when the shutter 41 is in the middle of moving toward the first opening 33a.

[0062] As the shutter 41 moves further, the first sensor 45a, which is closer to the first opening 33a, detects the shutter 41, while the second sensor 45b, which is closer to the second opening 33b, no longer detects the shutter 41. In this case, as shown in FIG. 6C , the first opening 33a is closed by the shutter 41, and the second opening 33b is open. Therefore, when the state where the shutter 41 is detected by both the first sensor 45a and the second sensor 45b changes to a state where the first sensor 45a detects the shutter 41 but the second sensor 45b does not detect the shutter 41, the controller 7 determines that the shutter 41 has closed the first opening 33a and stops the movement of the shutter 41 toward the first opening 33a. FIG. 6C illustrates a state where the first opening 33a is closed by the shutter 41.

[0063] 6C, with the second opening 33b open and the first opening 33a closed, the worker W can pass through the second opening 33b and enter the mounting section 31 to perform a predetermined task related to the item A. Meanwhile, with the first opening 33a closed, the conveying device 5 cannot extend the transfer device 53 to the mounting section 31. In this way, the safety device 4 prevents the transfer device 53 of the conveying device 5 from accessing the mounting section 31 while the worker W is accessing the mounting section 31, thereby ensuring safety.

[0064] As described above, in this embodiment, when the shutter 41 is moved to switch the opening to be closed, the shutter 41 moves from one opening to the other opening through the space SP between the floor F and the placement unit 31. As a result, even if an abnormality occurs during the movement of the shutter 41 and the shutter 41 stops midway from one opening to the other opening, the lower sides of the first opening 33a and the second opening 33b remain closed by the shutter 41, as shown in FIGS. 5B and 6B . In other words, even if the shutter 41 stops midway, the lower sides of the two openings do not open simultaneously. As a result, while the conveying device 5 is operating, the worker W cannot access the placement unit 31 or move toward the conveying device 5 through the placement unit 31. Furthermore, the transfer device 53 cannot access the placement unit 31 while the worker W is performing a predetermined task on the placement unit 31 or if the worker W is left behind on the placement unit 31.

[0065] If neither the first sensor 45a nor the second sensor 45b detects the shutter 41 while the shutter 41 is moving, the controller 7 determines that the shutter 41 is not in a normal position and issues an error alert.

[0066] (4-2) Startup operation When the safety device 4 is activated for the first time or after recovery from an abnormality, it may sometimes be impossible to determine the state of the shutter 41 (such as the position of the shutter 41) from the detection states of the shutter 41 by the first sensor 45a and the second sensor 45b. For example, if an abnormality occurs while the shutter 41 is detected by both the first sensor 45a and the second sensor 45b and the device is then restarted, the controller 7 is unable to determine the direction in which the shutter 41 was moving or the position at which the shutter 41 stopped. Similarly, if the shutter 41 stops while it is not detected by both the first sensor 45a and the second sensor 45b and the device is then restarted, the controller 7 is unable to determine not only the direction in which the shutter 41 was moving but also its position.

[0067] Therefore, when activating the safety device 4, the controller 7 moves the shutter 41 around the first opening 33a, the space SP between the placement section 31 and the floor F, the second opening 33b, and the upper part of the placement section 31, so that the first sensor 45a and the second sensor 45b detect or not detect the shutter 41. When moving the shutter 41 around at activation, for safety reasons, the shutter 41 exits from the lower part of the second opening 33b where the worker W is present, and then moves in a direction to close the second opening 33b.

[0068] By performing the above operation at startup, even if the state of the shutter 41 becomes unrecognizable due to recovery from an abnormal state or startup of the device, the controller 7 can grasp the state of the shutter 41. For example, when the shutter 41 is rotated, if both the first sensor 45a and the second sensor 45b detect the shutter 41, and then the second sensor 45b detects the shutter 41 but the first sensor 45a no longer detects the shutter 41, the controller 7 can grasp that the shutter 41 is in a state (position) in which the second opening 33b is closed.

[0069] The above activation operation may be terminated without moving the shutter 41 a full revolution when either of the first and second sensors 45a and 45b detects the shutter 41 after both the first and second sensors 45a and 45b have detected the shutter 41. Alternatively, the shutter 41 may be moved a plurality of revolutions, so that the two sensors repeatedly detect and do not detect the shutter 41.

[0070] (5) Features of the embodiment The above embodiment can also be explained as follows. An article placement platform (e.g., rack 3) includes a placement unit (e.g., placement unit 31), two openings (e.g., first opening 33a and second opening 33b), a shutter (e.g., shutter 41), a drive unit (e.g., drive unit 43), and a controller (e.g., controller 7). The placement unit is capable of placing an article (e.g., article A) at a position spaced above a floor surface (e.g., floor surface F). The two openings are arranged opposite each other in a direction (e.g., Y direction) perpendicular to the width direction (e.g., X direction) of the placement unit, and are for accessing the placement unit. The shutter opens one of the two openings and closes the other. The drive unit drives the shutter. The controller controls the drive unit to control the movement of the shutter. When moving the shutter to switch the opening to be closed, the controller passes the shutter through a space (e.g., space SP) between the floor surface and the placement unit.

[0071] In the above-mentioned article loading platform, when the shutter is moved to switch the opening to be closed, the shutter moves from one opening to the other opening, passing through the space between the floor and the loading section. As a result, even if the shutter stops midway through its movement from one opening to the other, the lower side of at least one of the two openings remains closed by the shutter, preventing the lower sides of both openings from being open at the same time.

[0072] 2. Other Embodiments Although one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and various modifications are possible within the scope of the gist of the invention. In particular, the multiple embodiments and modifications described in this specification can be arbitrarily combined as necessary. (A) The number of sensors that detect the shutter 41 is not limited to two. For example, an additional sensor (referred to as the third sensor 45c) may be provided between the first sensor 45a and the second sensor 45b. In other words, three sensors may be arranged side by side along the movement path of the shutter 41. By providing more sensors, the controller 7 can perform more advanced control.

[0073] In this case, the controller 7 determines whether to reduce the movement speed of the shutter 41 or stop the shutter 41 when the shutter 41 is no longer detected by any of the three sensors, the first sensor 45a to the third sensor 45c, depending on the movement direction of the shutter 41.

[0074] Specifically, for example, when moving the shutter 41 in a direction to close the second opening 33b, the controller 7 can reduce the movement speed of the shutter 41 when the shutter 41 is no longer detected by only the first sensor 45a after the shutter 41 has been detected by all of the first sensor 45a to the third sensor 45c, and then stop the shutter 41 when the first sensor 45a and the third sensor 45c no longer detect the shutter 41. At this time, the second sensor 45b continues to detect the shutter, so it is known that the edge of the shutter has stopped between the third sensor 45c and the second sensor 45b.

[0075] Furthermore, when moving the shutter 41 in a direction to close the first opening 33a, the controller 7 can reduce the movement speed of the shutter 41 when the shutter 41 is no longer detected by the second sensor 45b alone after the shutter 41 has been detected by all of the first sensor 45a to the third sensor 45c, and then stop the shutter 41 when the second sensor 45b and the third sensor 45c no longer detect the shutter 41. At this time, the first sensor 45a continues to detect the shutter, so it is known that the edge of the shutter has stopped between the third sensor 45c and the first sensor 45a.

[0076] (B) The safety device 4 can be provided not only on the rack 3 but also on a general table for placing the article A having two openings.

[0077] (C) The placement unit 31 may be capable of rising and falling in the Z direction. Examples of such a placement unit 31 that can rise and fall include a power slider and an elevator. This allows, for example, a worker W to access the placement unit 31 from the floor surface F. Also, for example, an automatic guided vehicle (AGV) traveling on the floor surface F can access the placement unit 31.

[0078] (D) An automated guided vehicle may be able to enter the space SP between the placement unit 31 and the floor surface F. In this case, for example, the automated guided vehicle has a placement platform for article A that can be raised and lowered in the vertical direction, and the automated guided vehicle can enter the space SP and lift up article A placed on the placement unit 31 using the placement platform, thereby transferring article A from the placement unit 31 to the placement platform.

[0079] As described above, the shutter 41 switches between the first opening 33a and the second opening 33b by passing through the space SP between the placement unit 31 and the floor surface F, and therefore the opening cannot be switched when an automated guided vehicle and / or a person, etc. is present in the space SP between the placement unit 31 and the floor surface F. As a result, it is possible to determine whether or not the opening can be switched without detecting with a sensor or the like whether or not an automated guided vehicle and / or a person, etc. is present in the space SP between the placement unit 31 and the floor surface F.

[0080] (E) The length of the shutter 41 can be any length as long as it is equal to or greater than the sum of the height of one opening and the length of the mounting section 31 in the Y direction. In addition, the length of the shutter 41 may be changeable depending on the length of the mounting section 31 in the Y direction.

[0081] (F) The driving members 43a and 43b may further be provided with a rotating member for adjusting the tension of the endless members 433a and 433b. This rotating member adjusts the tension by pushing or pulling the endless members 433a and 433b that are hung on the four rotating members 431a and 431b. Alternatively, the four rotating members 431a and 431b may be made movable in any direction, and the tension of the endless members 433a and 433b may be adjusted by adjusting the distance between the rotating members 431a and 431b.

[0082] (G) The movement of the shutter 41 is not limited to being realized by the control of the controller 7. For example, the movement of the shutter 41 may be realized by operating a button or the like. [Industrial Applicability]

[0083] The present invention can be widely applied to article placement tables on which articles are placed. [Explanation of symbols]

[0084] 1. Automated warehouse 3 racks 31 Placement section 33a First entrance 33b Second entrance 35 Workbench 4 Safety equipment 41 Shutter 41a Shutter member 41b shutter support member 43 Drive unit 43a, 43b driving members 431a, 431b Rotating members 433a, 433b Endless member 435 Drive Supply Unit 45a First sensor 45b Second sensor 45c 3rd sensor 5. Conveyor equipment 51 Guide rail 53 Transfer equipment 7 Controller 8 Upper controller 9 Control section A Goods F Floor FL1 First frame FL2 Second frame SP space W Worker

Claims

1. a placement section on which an article can be placed at a position above the floor surface; two openings arranged opposite to each other in a direction perpendicular to the width direction of the placement unit, for accessing the placement unit; a shutter that opens one of the two openings and closes the other; Equipped with When the shutter moves to switch the opening to be closed, the shutter passes through the space between the floor surface and the placement section. Goods storage stand.

2. a drive unit having a pair of drive members arranged at a distance wider than the width of the mounting unit and configured to move the shutter while supporting both ends of the shutter in the width direction; Each drive member is four rotating members arranged at four corners of the movement path of the shutter; an endless member that is hung on the four rotary members and supports one end of the shutter; The article platform of claim 1 , comprising:

3. The article platform according to claim 2 , wherein the drive unit moves the shutter by rotating one of four rotary members of the pair of drive members.

4. Further, two sensors are arranged side by side along the movement path of the shutter and detect the shutter; The shutter is Continue moving when both of the two sensors detect the shutter; Stopping when either of the two sensors does not detect the shutter. The article mounting table according to claim 1 .

5. The article platform according to claim 1 , further comprising three sensors arranged side by side along the movement path of the shutter to detect the shutter.

6. the shutter has a length corresponding to the sum of the height of the opening and the length in a direction perpendicular to the width direction of the placement section, The sensor is disposed near one of the frontages, The direction in which the shutter is stopped when the shutter is not detected by either of the two sensors is determined based on the moving direction of the shutter. The article mounting table according to claim 4 .

7. the shutter has a length corresponding to the sum of the height of the opening and the length in a direction perpendicular to the width direction of the placement section, The sensor is disposed near one of the frontages, When the shutter is no longer detected by any one of the three sensors, whether to reduce the movement speed of the shutter or stop the shutter is determined depending on the movement direction of the shutter. The article mounting table according to claim 5 .

8. 5. The article platform according to claim 4, wherein when the state of the shutter cannot be determined by the sensor, the state of the shutter is determined by moving the shutter in a circular motion and causing the sensor to detect the shutter.

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