Article transport equipment

Abstract

To provide a technology that can easily improve the efficiency of transporting articles by a lifting and transporting equipment when the lifting and transporting equipment is configured to have two lifting and transporting devices, an upper lifting and transporting device and a lower lifting and transporting device, and when the lifting and transporting equipment transports multiple articles from hierarchical conveying devices to carry-out devices.SOLUTION: Article transport equipment includes level transport devices 4 arranged on multiple levels, lifting transport devices that transport articles W in the vertical direction Z, and carry-out devices. The lifting transport devices include an upper lifting device 6U and a lower lifting device 6L. The control system executes a first selection process as a selection process for selecting articles W to be received by each of the upper lifting device 6U and the lower lifting device 6L, such that the level transport device 4 located on the lowest side Z1 among the level transport devices 4 on which the article W to be received by the upper lifting device 6U is arranged is located on an upper side Z2 than the level transport device 4 located on the highest side Z2 among the level transport devices 4 on which the article W to be received by the lower lifting device 6L is arranged.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to an item transport facility that includes a tiered transport device arranged on multiple levels in a vertically aligned fashion, a lifting transport device that transports items received from the tiered transport device in a vertical direction, and a discharge device that discharges the items received from the lifting transport device. [Background technology]

[0002] An example of such an article conveying facility is disclosed in Japanese Patent Application Laid-Open No. 2022-94209 (Patent Document 1). Hereinafter, in the description of this background art, the reference numerals in Patent Document 1 will be cited in parentheses. Patent Document 1 discloses an automated warehouse (100) including an outgoing conveyor (25) as a hierarchical conveying device, an outgoing lifting device (13) as a lifting conveying device, and an outgoing station (9) as a carrying-out device. The outgoing lifting device (13) includes a lifting platform (63) on which goods (W) as articles are placed, and a lifting mechanism (65) for raising and lowering the lifting platform (63).

[0003] When a package (W) is to be emptied from the automated warehouse (100), the eviction lifting device (13) raises and lowers the lifting platform (63) to the shelf (21) where the package (W) to be emptied is located, and receives the package (W) from the eviction conveyor (25) arranged on that shelf (21). The eviction lifting device (13) then raises and lowers the lifting platform (63) to the position of the eviction station (9) and delivers the package (W) to the eviction station (9). In the automated warehouse (100) of Patent Document 1, once all the packages (W) included in one order are collected, the multiple packages (W) included in that order are emptied from the automated warehouse (100). In the automated warehouse (100) of Patent Document 1, when the packages (W) are received, the multiple packages (W) included in one order are distributed across multiple shelves (21) up to an upper limit to determine the receiving position, thereby improving eviction efficiency. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2022-94209 Summary of the Invention [Problem to be solved by the invention]

[0005] Incidentally, it is conceivable that the lifting and conveying device may be configured to include two lifting and conveying devices, an upper lifting and conveying device and a lower lifting and conveying device. Even in such a configuration, when a plurality of items (in Patent Document 1, a plurality of parcels included in one order) are conveyed from a level conveying device to a carry-out device by the lifting and conveying device, it is desirable to be able to improve the transport efficiency of the items by the lifting and conveying device (in Patent Document 1, the warehousing efficiency). However, Patent Document 1 does not describe a configuration in which the lifting and conveying device includes two lifting and conveying devices, an upper lifting and conveying device and a lower lifting and conveying device.

[0006] Therefore, in a configuration in which the lifting and conveying device has two lifting and conveying devices, an upper lifting and conveying device and a lower lifting and conveying device, when multiple items are transported from a tiered conveying device to a carry-out device by the lifting and conveying device, it is desirable to realize technology that can easily increase the efficiency of transporting items by the lifting and conveying device. [Means for solving the problem]

[0007] The item transport equipment disclosed herein is an item transport equipment comprising: a tiered transport device arranged in a vertical line on multiple levels; a lifting transport device that transports items received from the tiered transport device in a vertical direction; a discharge device that discharges the items received from the lifting transport device; and a control system that controls the tiered transport device and the lifting transport device, wherein the lifting transport device comprises an upper lifting device that moves vertically along a lifting path, and a lower lifting device that moves vertically along the lifting path below the upper lifting device, and the upper lifting device and the lower lifting device are each configured to hold a plurality of the items, and the control system performs a first selection process to select the items to be received by each of the upper lifting device and the lower lifting device, such that the lowest tiered transport device among the tiered transport devices on which the items to be received by the upper lifting device are arranged is above the highest tiered transport device among the tiered transport devices on which the items to be received by the lower lifting device are arranged.

[0008] According to this configuration, when multiple items are transported from a tiered conveying device to a carry-out device by an elevator conveying device, the first selection process can be performed to prevent the vertical range in which the upper elevator device receives items from the tiered conveying device from overlapping with the vertical range in which the lower elevator device receives items from the tiered conveying device. This makes it easier to overlap the period in which the upper elevator device performs the receiving operation to receive items from the tiered conveying device with the period in which the lower elevator device performs the receiving operation to receive items from the tiered conveying device. This makes it easier to improve the efficiency of transporting items by the elevator conveying device.

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

[0010] [Figure 1] A perspective view of a part of the article transport facility [Figure 2] Control Block Diagram [Figure 3]FIG. 10 is a diagram showing the article holding patterns of the upper and lower lifting devices; [Figure 4] An explanatory diagram of the operation of receiving an article from the hierarchical conveying device by the lifting conveying device. [Figure 5] An explanatory diagram of the operation of delivering an article to a carry-out device by a lifting and transporting device. [Figure 6] FIG. 10 is a diagram showing one mode of an article receiving operation by the lifting and conveying device; [Figure 7] FIG. 10 is a diagram showing one mode of an article receiving operation by the lifting and conveying device; [Figure 8] FIG. 10 is a diagram showing an arrangement pattern of items in a tiered conveying device corresponding to pattern 1. [Figure 9] FIG. 10 is a diagram showing an arrangement pattern of items in a tiered conveying device corresponding to pattern 2. [Figure 10] FIG. 10 is a diagram showing an arrangement pattern of items in a tiered conveying device corresponding to pattern 3. [Figure 11] FIG. 10 is a diagram showing an arrangement pattern of items in a tiered conveying device corresponding to pattern 4. [Figure 12] FIG. 10 is a diagram showing an arrangement pattern of items in a tiered conveying device corresponding to pattern 5. [Figure 13] FIG. 10 is a diagram showing an arrangement pattern of items in a tiered conveying device corresponding to pattern 6. [Figure 14] FIG. 10 is a diagram showing one mode of an article receiving operation by the lifting and conveying device; [Figure 15] FIG. 10 is a diagram showing one mode of an article receiving operation by the lifting and conveying device; [Figure 16] FIG. 10 is a diagram showing one mode of an article receiving operation by the lifting and conveying device; [Figure 17] FIG. 10 is a diagram showing one mode of an article receiving operation by the lifting and conveying device; DETAILED DESCRIPTION OF THE INVENTION

[0011] An embodiment of an article transport facility will be described with reference to the drawings. As shown in Figs. 1 and 2, the article transport facility 100 includes a level transport device 4, an elevator transport device 6, a carry-out device 2, and a control system C. The article transport facility 100 further includes a storage shelf 1, a carry-in device 3, and a transport vehicle 5. Various technical features of the control system C described below can also be applied to an article transport method in an article transport facility and an article transport program for controlling the article transport facility (a program for causing a computer to function as the control system C), and such methods and programs, as well as a storage medium on which such a program is stored (for example, a computer-readable storage medium such as an optical disk flash memory), are also disclosed by this specification.

[0012] As shown in FIG. 2, the control system C controls the hierarchical conveying device 4 and the lifting conveying device 6. The control system C further controls the unloading device 2, the loading device 3, and the transport vehicle 5. The control system C controls the operation of the device to be controlled by controlling the driving of a drive power source (e.g., an electric motor) provided in the device. Each function of the control system C is realized, for example, by cooperation between hardware such as an arithmetic processing device and a program executed on the hardware. The control system C may be configured not by a single piece of hardware, but by a collection of multiple pieces of hardware (multiple separate pieces of hardware) that can communicate with each other. Furthermore, the device to be controlled by the control system C (e.g., a controller provided in the device) may constitute at least a part of the control system C.

[0013] As shown in FIG. 1, two mutually perpendicular horizontal directions are defined as the X direction and the Y direction, and the storage shelves 1 are arranged such that the shelf width direction is along the X direction and the shelf depth direction is along the Y direction. The transport vehicle 5 travels along the X direction to transport the items W. In the example shown in FIG. 1, a pair of storage shelves 1 are arranged facing each other in the Y direction, and the transport vehicle 5 travels along the X direction between the pair of storage shelves 1 in the Y direction. In the example shown in FIG. 1, the transport vehicle 5 is configured to transport the items W one by one, but the transport vehicle 5 can also be configured to transport multiple items W (for example, two items W) together. The transport vehicle 5 can also be configured to include two carriages: a first carriage that travels along the X direction, and a second carriage that can be loaded onto the first carriage and is separated from the first carriage to travel along the Y direction to transport the items W.

[0014] The storage shelf 1 is equipped with shelf sections 10 that support items W, and the items W are stored on the storage shelf 1 while being supported by the shelf sections 10. The shelf sections 10 are arranged on multiple levels so as to be lined up in the Z direction, which is the up-down direction (vertical direction), and the storage shelf 1 is configured so that items W can be stored on each of the multiple levels (tiers). The items W are, for example, containers (containers, cardboard boxes, etc.) that store loads (goods, etc.). The travel path of the transport vehicle 5 is formed corresponding to each of the shelf sections 10 arranged on the multiple levels. Here, the travel path of the transport vehicle 5 is formed by a pair of rails 50 that are arranged at a distance in the Y direction.

[0015] 1 shows only some of the articles W, the shelf unit 10 is configured to be able to support the articles W at multiple positions in the X direction. In other words, the shelf unit 10 is configured to be able to support multiple articles W lined up in the X direction. The shelf unit 10 may also be configured to be able to support multiple articles W (for example, two articles W) lined up in the Y direction at each position in the X direction.

[0016] As shown in FIG. 1, tier conveying devices 4 are arranged in multiple levels, lined up in the Z direction. In the example shown in FIG. 1, a tier conveying device 4 is provided corresponding to each of the shelf units 10 arranged in multiple levels. A group of tier conveying devices 4 arranged in multiple levels is referred to as a tier conveying device group, and in the example shown in FIG. 1, a pair of tier conveying device groups are arranged on either side of the travel path of the transport vehicle 5 in the Y direction. FIG. 1 shows shelf units 10 arranged on six levels of the storage shelf 1 and tier conveying devices 4 arranged on six levels. FIG. 1 also shows the transport vehicle 5 arranged on the highest level of the six levels.

[0017] The transport of the item W between the shelf section 10 arranged on the same floor and the floor conveying device 4 is performed by the transport vehicle 5. The transfer of the item W between the transport vehicle 5 and the location to which the item W is to be transferred (the shelf section 10 or the floor conveying device 4) is performed, for example, by a transfer device provided on the transport vehicle 5.

[0018] The hierarchical conveying device 4 conveys the article W in the horizontal direction (here, the X direction). The hierarchical conveying device 4 is equipped with a conveyor (such as a roller conveyor or a belt conveyor, the same applies below) that conveys the article W in the X direction. The hierarchical conveying device 4 delivers the article W to the lifting / lowering conveying device 6 or receives the article W from the lifting / lowering conveying device 6 by the conveying operation of the conveyor (here, in cooperation with the conveying operation of the article W by a conveyor provided in the lifting / lowering conveying device 6). The hierarchical conveying device 4 is also configured to be able to support multiple articles W lined up in the horizontal direction (here, the X direction). In the example shown in FIG. 1, the hierarchical conveying device 4 is configured to be able to support three articles W lined up in the X direction.

[0019] The lifting and lowering conveying device 6 conveys the item W in the Z direction. In the example shown in FIG. 1, a pair of lifting and lowering conveying devices 6 are arranged side by side in the Y direction. The lifting and lowering conveying device 6 conveys the item W received from the level conveying device 4 in the Z direction. The lifting and lowering conveying device 6 also conveys the item W received from the loading device 3 in the Z direction.

[0020] The lifting and conveying device 6 includes an upper lifting device 6U that moves in the Z direction along a lifting path 60, and a lower lifting device 6L that moves in the Z direction along the lifting path 60 on a side Z1 below the upper lifting device 6U. The lifting path 60 is formed, for example, by a mast or a rail. The upper lifting device 6U and the lower lifting device 6L move in the Z direction along the same lifting path 60. Therefore, the upper lifting device 6U can move in the Z direction within a range whose lower limit is a position where it interferes with the lower lifting device 6L, and the lower lifting device 6L can move in the Z direction within a range whose upper limit is a position where it interferes with the upper lifting device 6U.

[0021] The transfer of the item W between the upper lifting device 6U and the transfer target location of the item W (the level conveying device 4, the carry-out device 2, or the carry-in device 3; the same applies below) is performed when the upper lifting device 6U moves in the Z direction to a height corresponding to the transfer target location and is positioned at that height. The transfer of the item W between the lower lifting device 6L and the transfer target location of the item W is performed when the lower lifting device 6L moves in the Z direction to a height corresponding to the transfer target location and is positioned at that height. Each of the upper lifting device 6U and the lower lifting device 6L is equipped with a conveyor that transports the item W in the horizontal direction (here, the X direction), and receives the item W from the transfer target location or delivers the item W to the transfer target location by the conveyor's transport operation (here, in cooperation with the transport operation of the item W by a conveyor provided at the transfer target location).

[0022] The upper lifting device 6U and the lower lifting device 6L are each configured to be able to hold a plurality of articles W. The plurality of articles W are held so as to be aligned in the horizontal direction (here, the X direction) in each of the upper lifting device 6U and the lower lifting device 6L. As shown in FIG. 1, the upper lifting device 6U and the lower lifting device 6L are configured to be able to hold the same number of articles W. Specifically, the upper lifting device 6U and the lower lifting device 6L are each configured to be able to hold two articles W.

[0023] Each of the upper lifting device 6U and the lower lifting device 6L holds one or more items W received from the tiered conveying device 4 or the loading device 3. When receiving multiple items W (here, two items W, the same applies below) from the tiered conveying device 4, each of the upper lifting device 6U and the lower lifting device 6L may receive multiple items W from one tiered conveying device 4, or may receive a total of multiple items W from multiple tiered conveying devices 4. Each of the upper lifting device 6U and the lower lifting device 6L is controlled by the control system C to receive items W selected by the selection process described below.

[0024] The carry-out device 2 carries out the goods W received from the lifting and conveying device 6 to an outgoing line or the like. The carry-in device 3 hands over the goods W carried in from an incoming line or the like to the lifting and conveying device 6. The carry-out device 2 and the carry-in device 3 are equipped with conveyors that transport the goods W in a horizontal direction (here, the X direction).

[0025] One side in the X direction is designated as the X-direction first side X1, and the other side in the X direction is designated as the X-direction second side X2. In the example shown in FIG. 1, the pair of lifting and conveying devices 6 are arranged on the X-direction first side X1 with respect to the storage shelf 1. Furthermore, one side in the Y direction is designated as the Y-direction first side Y1, and the other side in the Y direction is designated as the Y-direction second side Y2. In the example shown in FIG. 1, of the pair of lifting and conveying devices 6, the lifting and conveying device 6 arranged on the Y-direction first side Y1 is used for retrieval, and the lifting and conveying device 6 arranged on the Y-direction second side Y2 is used for storage. Furthermore, of the pair of tiered conveying device groups (groups of tiered conveying devices 4 arranged on multiple levels), the tiered conveying device group arranged on the Y-direction first side Y1 is used for retrieval, and the tiered conveying device group arranged on the Y-direction second side Y2 is used for retrieval.

[0026] The outgoing elevator conveying device 6 is arranged at a position in the Y direction where it can receive the item W from the outgoing tiered conveying device group, and the incoming elevator conveying device 6 is arranged at a position in the Y direction where it can deliver the item W to the incoming tiered conveying device group. Furthermore, the carrying-out device 2 is arranged at a position in the Y direction where it can receive the item W from the outgoing elevator conveying device 6, and the carrying-in device 3 is arranged at a position in the Y direction where it can deliver the item W to the incoming elevator conveying device 6. Note that, unlike the example shown in FIG. 1, it is also possible to configure the carrying-in device 3 to be arranged on the second side X2 in the X direction with respect to the storage shelf 1, and the elevator conveying device 6 arranged on the second side X2 in the X direction with respect to the storage shelf 1 to be used for carrying-in.

[0027] An item W to be stored in the item conveying equipment 100 (specifically, storage shelf 1) is handed over from the carry-in device 3 to the elevator conveying device 6 for storage. The elevator conveying devices 6 (specifically, each of the upper elevator device 6U and the lower elevator device 6L) convey the item W received from the carry-in device 3 in the Z direction and hand it over to a hierarchical conveying device 4 that constitutes the group of hierarchical conveying devices for storage and that is located on the same level as the shelf section 10 where the item W is to be stored. The item W handed over to the hierarchical conveying device 4 is then transported by a transport vehicle 5 to the storage position of the item W on the shelf section 10 and stored in that storage position.

[0028] An item W to be removed from the item transport equipment 100 (specifically, storage shelf 1) is transported by a transport vehicle 5 from the storage position of the item W on the shelf section 10 to a tiered transport device 4 that constitutes a group of tiered transport devices for removal from the warehouse. The tiered transport device 4 hands over the item W received from the transport vehicle 5 to an elevating transport device 6 for removal from the warehouse. The elevating transport devices 6 (specifically, each of the upper elevating device 6U and the lower elevating device 6L) transport the item W received from the tiered transport device 4 in the Z direction and hand it over to the carry-out device 2.

[0029] As shown in Fig. 5, the carry-out device 2 is configured to receive an article W from each of the upper lifting device 6U and the lower lifting device 6L at a predetermined position in the Z direction. As shown in Figs. 1 and 5, the Z direction positions at which the carry-out device 2 receives the article W from each of the upper lifting device 6U and the lower lifting device 6L are biased toward a lower side Z1, which is one side in the Z direction, within the entire Z direction area of ​​the lifting path 60. In this embodiment, the lower side Z1 corresponds to the "first side in the vertical direction."

[0030] The following provides a specific description of the retrieval processing of the item W by the control system C. Therefore, in the following description, the hierarchical conveying device 4 refers to the hierarchical conveying device 4 used for retrieval, and the lifting conveying device 6 refers to the lifting conveying device 6 used for retrieval.

[0031] The control system C performs the retrieval process of the items W by repeatedly executing one cycle, which is a series of retrieval operations in which the lifting and conveying device 6 receives items W from the tiered conveying device 4 and then transports the items W to the transport device 2. In each cycle, the same number of items W (here, four items W) as the maximum number of items W that can be held by the upper lifting and conveying device 6U and the lower lifting and conveying device 6L are targeted for retrieval process. In each cycle, items W selected by a selection process described below are targeted for retrieval process. As described below, if the lifting and conveying device 6 is unable to receive the same number of items W as the maximum number from the tiered conveying device 4 in each cycle, the control system C designates the items W that could not be received in that cycle as the retrieval target for the next cycle. In each cycle, the operation of the upper lifting device 6U and the lower lifting device 6L is controlled so that the period during which the upper lifting device 6U performs the receiving operation of receiving an item W from the hierarchical conveying device 4 and the period during which the lower lifting device 6L performs the receiving operation of receiving an item W from the hierarchical conveying device 4 overlap as much as possible, provided that there is no interference between the upper lifting device 6U and the lower lifting device 6L.

[0032] When multiple items W are transported from the level transport device 4 to the carry-out device 2 by the lifting and transporting device 6, the control system C executes a selection process to select the items W to be received by each of the upper lifting and transporting device 6U and the lower lifting and transporting device 6L. The control system C executes a first selection process as the selection process.

[0033] The first selection process is a selection process in which the lowest level conveying device 4 Z1 among the level conveying devices 4 on which the items W to be received by the upper lifting device 6U are arranged is located above the highest level conveying device 4 Z2 among the level conveying devices 4 on which the items W to be received by the lower lifting device 6L are arranged. Note that if all of the items W to be received by the upper lifting device 6U are arranged on a single level conveying device 4, that level conveying device 4 becomes the above-mentioned lowest level conveying device 4 Z1. Also, if all of the items W to be received by the lower lifting device 6L are arranged on a single level conveying device 4, that level conveying device 4 becomes the above-mentioned highest level conveying device 4 Z2. In the first selection process, the items W to be received by each of the upper lifting device 6U and the lower lifting device 6L are basically selected so that the upper lifting device 6U and the lower lifting device 6L receive the maximum number of items W that they can hold (here, so that a total of four items W are received).

[0034] FIG. 4 shows how the upper lifting device 6U and the lower lifting device 6L each receive the item W selected by the first selection process. In FIGS. 3 to 17, including FIG. 4, a number indicating the delivery order, which will be described later, is shown inside the rectangle representing the item W. Hereinafter, the item W that is Nth in the delivery order will be referred to as item W[N]. In FIG. 4, items W[1] and W[2] are selected as the items W to be received by the upper lifting device 6U, and items W[3] and W[4] are selected as the items W to be received by the lower lifting device 6L. In this case, the Z-direction range in which the upper lifting device 6U receives items W from the level conveying device 4 (hereinafter referred to as the "first range") is the Z-direction range between the level conveying device 4 on which item W[1] is placed and the level conveying device 4 on which item W[2] is placed. Furthermore, the Z-direction range in which the lower lifting device 6L receives the item W from the tiered conveying device 4 (hereinafter referred to as the "second range") is the Z-direction range between the tiered conveying device 4 on which the item W[3] is placed and the tiered conveying device 4 on which the item W[4] is placed. The first selection process can prevent the first range and the second range from overlapping. In Figure 4 and Figures 5 to 7 and 14 to 17, which will be referred to later, the diagram shown in (b) represents a later point in time than the diagram shown in (a).

[0035] When the control system C cannot execute the first selection process as the selection process (specifically, when the first selection process is unable to receive the maximum number of articles W that the upper lifting device 6U and the lower lifting device 6L can hold), the control system C executes the second selection process as the selection process. In this way, the control system C executes the first selection process with priority. Then, when the first selection process is unable to receive the maximum number of articles W that the upper lifting device 6U and the lower lifting device 6L can hold, the control system C executes another selection process (here, the second selection process) with priority given to receiving the maximum number of articles W that the upper lifting device 6U and the lower lifting device 6L can hold.

[0036] The second selection process is a selection process that ensures that the lowest level conveying device 4 Z1 among the level conveying devices 4 on which the items W to be received by the upper lifting device 6U are arranged is the same as the highest level conveying device 4 Z2 among the level conveying devices 4 on which the items W to be received by the lower lifting device 6L are arranged. In the second selection process, the upper lifting device 6U and the lower lifting device 6L basically select the items W to be received by each of them so that they receive the maximum number of items W that they can hold. Figures 6, 7, and 14 show how the upper lifting device 6U and the lower lifting device 6L each receive the items W selected by the second selection process. In these figures, items W[1] and W[2] are selected as the items W to be received by the upper lifting device 6U, and items W[3] and W[4] are selected as the items W to be received by the lower lifting device 6L.

[0037] As shown in Fig. 5, the control system C is configured to execute a delivery process for delivering a plurality of items W from the upper lifting device 6U and the lower lifting device 6L to the carry-out device 2 in a predetermined delivery order. The delivery order is determined, for example, based on an order (such as a shipping order generated based on an order from a shipping destination of the items W). The order is generated by the control system C or another control device capable of communicating with the control system C (for example, a higher-level management device of the control system C).

[0038] In the delivery process, the upper lifting device 6U or the lower lifting device 6L moves in the Z direction to a height corresponding to the carry-out device 2 to deliver the item W to the carry-out device 2 in the following order: the lifting device holding the item W[1], the lifting device holding the item W[2], the lifting device holding the item W[3], and the lifting device holding the item W[4]. If two items W with consecutive delivery orders are held by the same lifting device, the two items W are delivered to the carry-out device 2 in the order according to the delivery order, with the lifting device positioned at a height corresponding to the carry-out device 2. In the example shown in FIG. 5, the upper lifting device 6U holding items W[1] and W[2] moves in the Z direction to a height corresponding to the carry-out device 2 and delivers items W[1] and W[2] to the carry-out device 2 (see FIG. 5(a)). Then, the lower lifting device 6L holding items W[3] and W[4] moves in the Z direction to a height corresponding to the carry-out device 2 and delivers items W[3] and W[4] to the carry-out device 2 (see FIG. 5(b)). Note that when items W[1], W[2], W[3], and W[4] are all delivered to the carry-out device 2, the delivery order for the other items W moves up by four. Therefore, items W[5], W[6], W[7], and W[8] become the new items W[1], W[2], W[3], and W[4].

[0039] Hereinafter, the four articles W, namely, article W[1], article W[2], article W[3], and article W[4], will be simply referred to as the four articles W. FIG. 3 shows the holding patterns of the four articles W in the upper lifting device 6U and the lower lifting device 6L. Each of the upper lifting device 6U and the lower lifting device 6L delivers the articles W to the carry-out device 2 in order, starting with the articles W held on the first side X1 in the X direction (the side where the carry-out device 2 is located). Therefore, by holding the four articles W in the upper lifting device 6U and the lower lifting device 6L in one of the six holding patterns (pattern 1 to pattern 6) shown in FIG. 3, the four articles W can be delivered from the upper lifting device 6U and the lower lifting device 6L to the carry-out device 2 in a predetermined delivery order.

[0040] 4, 6, and 7 show a situation in which four items W are held by the upper lifting device 6U and the lower lifting device 6L in pattern 1 shown in FIG. 3. FIG. 4 shows a first selection process being executed as a selection process, and the items W selected by the first selection process being received by the upper lifting device 6U and the lower lifting device 6L, respectively. FIGS. 6 and 7 show a second selection process being executed as a selection process, and the items W selected by the second selection process being received by the upper lifting device 6U and the lower lifting device 6L, respectively. Each of the upper lifting device 6U and the lower lifting device 6L receives the multiple items W so that the item W that is first in the delivery order is placed on the first side X1 in the X direction (the side where the carry-out device 2 is located). Specifically, each of the upper lifting device 6U and the lower lifting device 6L receives the multiple items W in order, starting with the item W that is first in the delivery order.

[0041] The transfer of the items W from the tier conveying device 4 to the lifting conveying device 6 is performed in order, starting with the items W arranged on the first side X1 in the X direction (the side on which the lifting conveying device 6 is arranged). Therefore, as shown in Figures 6 and 7, when multiple items W (two items W in Figure 6 and three items W in Figure 7) out of four items W are arranged on the tier conveying device 4 on the same floor, the transport vehicle 5 transports the multiple items W from the shelf section 10 to the tier conveying device 4 so that the item W that is first in the transfer order is arranged on the first side X1 in the X direction on the tier conveying device 4.

[0042] As shown in patterns 1 and 2 in FIG. 3, the "first condition" is that the articles W are held in consecutive order according to the delivery order in each of the upper lifting device 6U and the lower lifting device 6L. Also, as shown in patterns 3 and 4 in FIG. 3, the "second condition" is that the articles W are held in consecutive order according to the delivery order in either the upper lifting device 6U or the lower lifting device 6L (the lower lifting device 6L in pattern 3, and the upper lifting device 6U in pattern 4). While the technology disclosed herein is not limited to such a configuration, in this embodiment, the control system C executes the selection process as follows in both the first selection process and the second selection process. The control system C executes the selection process so as to satisfy the first condition. If the control system C cannot execute the selection process so as to satisfy the first condition, it executes the selection process so as to satisfy the second condition. If the control system C cannot execute the selection process so as to satisfy either the first condition or the second condition, it executes the selection process so as to satisfy neither the first condition nor the second condition. Because the control system C executes the selection process in this manner, patterns 1 and 2 are selected with priority over patterns 3 to 6, and patterns 3 and 4 are selected with priority over patterns 5 and 6.

[0043] Although the technology disclosed herein is not limited to this configuration, in the present embodiment, the control system C executes the selection process as follows in both the first selection process and the second selection process. In the selection process, the control system C ensures that the one of the upper lifting device 6U and the lower lifting device 6L located on the first vertical side holds the item W that is later in the delivery order, as in patterns 1, 3, and 5. In the present embodiment, the first vertical side is the lower side Z1, and the one of the upper lifting device 6U and the lower lifting device 6L located on the first vertical side is the lower lifting device 6L. If the control system C cannot ensure that the one of the upper lifting device 6U and the lower lifting device 6L located on the first vertical side holds the item W that is later in the delivery order, the control system C ensures that the one of the upper lifting device 6U and the lower lifting device 6L located on the second vertical side, which is opposite to the first vertical side, holds the item W that is later in the delivery order, as in patterns 2, 4, and 6. In this embodiment, the second side in the vertical direction is the upper side Z2, and of the upper lifting device 6U and the lower lifting device 6L, the one arranged on the second side in the vertical direction is the upper lifting device 6U. Since the control system C performs the selection process in this manner, patterns 1, 3, and 5 are selected with priority over patterns 2, 4, and 6.

[0044] In this way, patterns 1 and 2 are selected with priority over patterns 3 to 6, and patterns 3 and 4 are selected with priority over patterns 5 and 6. Furthermore, patterns 1, 3, and 5 are selected with priority over patterns 2, 4, and 6. Therefore, the six holding patterns shown in FIG. 3 are, in order of priority, pattern 1, pattern 2, pattern 3, pattern 4, pattern 5, and pattern 6.

[0045] Because the control system C executes the selection process as described above, which of the six holding patterns shown in FIG. 3 the four items W will be held in by the upper lifting device 6U and the lower lifting device 6L is determined according to the arrangement pattern of the four items W on the level conveying device 4, or according to the priority relationship between the arrangement pattern and the six holding patterns. The selection rules for the holding patterns (FIG. 3) corresponding to the arrangement patterns of the four items W shown in FIGS. 8 to 13 are set taking into consideration the priority relationships described above. Therefore, by selecting a holding pattern corresponding to the arrangement pattern of the four items W according to the selection rules shown in FIGS. 8 to 13, the selection process takes into consideration the priority relationships described above. Note that the selection rules for the holding patterns shown in FIGS. 8 to 13 are merely examples and can be changed as appropriate depending on the content of the priority relationships considered in the selection process, whether or not the priority relationships are considered in the selection process, etc.

[0046] Each of Figures 8 to 13 shows the arrangement patterns of four items W on a tier conveying device 4. In these figures, only tier conveying devices 4 on which at least one of the four items W is arranged are shown lined up in the Z direction. In each figure, two tier conveying devices 4 adjacent in the Z direction do not necessarily have to be two tier conveying devices 4 arranged on adjacent levels in the Z direction; another tier conveying device 4 may be arranged between these two tier conveying devices 4 in the Z direction. In Figures 8 to 13, an arrangement pattern in which four items W are arranged on four tier conveying devices 4 is classified as "four levels," an arrangement pattern in which four items W are arranged on three tier conveying devices 4 is classified as "three levels," and an arrangement pattern in which four items W are arranged on two tier conveying devices 4 is classified as "two levels." Note that which arrangement pattern the four items W are arranged on the tier conveying device 4 is determined depending on which level (tier) of shelf section 10 these four items W are stored on.

[0047] When four items W are placed on the hierarchical conveying device 4 in any of the arrangement patterns shown in Figure 8, a selection process is performed so that the four items W are held by the upper lifting device 6U and the lower lifting device 6L in pattern 1. That is, items W[1] and W[2] are selected as items W to be received by the upper lifting device 6U, and items W[3] and W[4] are selected as items W to be received by the lower lifting device 6L. The arrangement patterns of the four items W shown in Figures 4(a), 6(a), and 7(a) are included in the arrangement patterns shown in Figure 8.

[0048] In this way, when four items W are arranged on the tiered conveying device 4 in any of the arrangement patterns shown in Figure 8, items W[1] and W[2] are selected as items W to be received by the upper lifting device 6U, and items W[3] and W[4] are selected as items W to be received by the lower lifting device 6L, so that the items W are held in pattern 1. When four items W are arranged on the tiered conveying device 4 in any of the arrangement patterns shown in Figure 9, items W[3] and W[4] are selected as items W to be received by the upper lifting device 6U, and items W[1] and W[2] are selected as items W to be received by the lower lifting device 6L, so that the items W are held in pattern 2.

[0049] When four items W are arranged on the tiered conveying device 4 in any of the arrangement patterns shown in Figure 10, items W[1] and W[4] are selected as items W to be received by the upper lifting device 6U, and items W[2] and W[3] are selected as items W to be received by the lower lifting device 6L, so that the items W are held in pattern 3. When four items W are arranged on the tiered conveying device 4 in any of the arrangement patterns shown in Figure 11, items W[2] and W[3] are selected as items W to be received by the upper lifting device 6U, and items W[1] and W[4] are selected as items W to be received by the lower lifting device 6L, so that the items W are held in pattern 4.

[0050] When four items W are arranged on the tiered conveying device 4 in any of the arrangement patterns shown in Figure 12, items W[1] and W[3] are selected as items W to be received by the upper lifting device 6U, and items W[2] and W[4] are selected as items W to be received by the lower lifting device 6L, so that the items W are held in pattern 5. When four items W are arranged on the tiered conveying device 4 in any of the arrangement patterns shown in Figure 13, items W[2] and W[4] are selected as items W to be received by the upper lifting device 6U, and items W[1] and W[3] are selected as items W to be received by the lower lifting device 6L, so that the items W are held in pattern 6.

[0051] In addition, when all four items W are stored on the shelf 10 of the same level, as shown in FIG. 14, all four items W are delivered from the same level conveying device 4 to the lifting conveying device 6. In FIG. 14, from a state in which items W[1], W[2], and W[3] are arranged on the same level conveying device 4, items W[1] and W[2] are delivered to the upper lifting device 6U, and item W[4] is placed on the level conveying device 4. Then, items W[3] and W[4] are delivered to the lower lifting device 6L. In this way, when all four items W are stored on the shelf 10 of the same level, items W[1] and W[2] are selected as items W to be received by the upper lifting device 6U, and items W[3] and W[4] are selected as items W to be received by the lower lifting device 6L, so that the items W are held in pattern 1.

[0052] However, there may be a level conveying device 4 in which only the upper lifting device 6U can receive items W (hereinafter referred to as an "upper-side limited level conveying device"), and a level conveying device 4 in which only the lower lifting device 6L can receive items W (hereinafter referred to as a "lower-side limited level conveying device"). For example, as shown in Figures 15 to 17, the upper lifting device 6U cannot retreat to the upper side Z2 due to the presence of a ceiling or the like, so two level conveying devices 4 from the upper side Z2 (i.e., the level conveying device 4 on the top floor and the floor below) may become upper-side limited level conveying devices. In this case, if three or more of the four items W are placed on the upper-side limited level conveying device, neither the first selection process nor the second selection process can receive the maximum number of items W that the upper lifting device 6U and the lower lifting device 6L can hold (here, four items W).

[0053] Furthermore, although not shown in the figures, there are cases where the lower lifting device 6L cannot retreat to the lower side Z1 due to the presence of a floor or the like, and therefore two level conveying devices 4 from the lower side Z1 (i.e., the level conveying device 4 on the lowest level and the level one level above) become lower-limited level conveying devices. In this case, if three or more of the four items W are placed on the lower-limited level conveying devices, neither the first selection process nor the second selection process can receive the maximum number of items W that the upper lifting device 6U and the lower lifting device 6L can hold.

[0054] Furthermore, if the size or shape of the items W includes an item W that can only be received by either the upper lifting device 6U or the lower lifting device 6L, it may be impossible to receive the maximum number of items W that the upper lifting device 6U and the lower lifting device 6L can hold.

[0055] If the control system C is unable to receive the maximum number of items W that the upper lifting device 6U and the lower lifting device 6L can hold in both the first selection process and the second selection process, it executes the first selection process or the second selection process to receive items W that are less than the maximum number that the upper lifting device 6U and the lower lifting device 6L can hold, and the remaining items W are made the target of the next first selection process or the second selection process.The items W that are less than the maximum number (here, three or less items W) are considered to be one or more items W that are consecutive in the delivery order from the first item W (i.e., item W[1]) in the delivery order.

[0056] In the situation shown in Figure 15, four items W are arranged on the level conveying device 4 in an arrangement pattern (see Figure 8) that can hold items W in pattern 1, but the lower lifting device 6L cannot receive item W[3] and item W[4]. In other words, the upper lifting device 6U and the lower lifting device 6L cannot receive the maximum number of items W that they can hold (here, four items W). Therefore, a first selection process or a second selection process (here, the first selection process) is performed to receive fewer items W than the maximum number that the upper lifting device 6U and the lower lifting device 6L can hold, and the remaining items W are made the target of the next first selection process or second selection process. In Figure 15, items W[1] and W[2] are selected as items W to be received by the upper lifting device 6U, and items W[3] and W[4] are made the target of the next first selection process or second selection process. Specifically, item W[N] in the next cycle becomes item W[N'], item W[3] becomes item W[1'], item W[4] becomes item W[2'], item W[5] becomes item W[3'], and item W[6] becomes item W[4'].

[0057] 15, the level conveying device 4 on which the item W to be received by the lower lifting device 6L is arranged is deemed to be located below the lowest level conveying device 4, Z1, and although not shown, when the upper lifting device 6U is not arranged on which the item W to be received by the upper lifting device 6U is arranged is deemed to be located above the highest level conveying device 4, Z2. Therefore, in these cases, the level conveying device 4 on the lowest level Z1 among the level conveying devices 4 on which the item W to be received by the upper lifting device 6U is arranged is located above the highest level conveying device 4 on which the item W to be received by the lower lifting device 6L is arranged, Z2, and the first selection process is executed.

[0058] In the situation shown in Figure 16, the lower lifting device 6L cannot receive item W[4]. In Figure 16, by executing the first selection process, item W[1] and item W[2] are selected as items W to be received by the upper lifting device 6U, and item W[3] is selected as item W to be received by the lower lifting device 6L. Then, item W[4] is the target of the next first selection process or second selection process. Specifically, item W[4] becomes item W[1'], item W[5] becomes item W[2'], item W[6] becomes item W[3'], and item W[7] becomes item W[4'].

[0059] In the situation shown in Figure 17, the lower lifting device 6L cannot receive item W[3] and item W[4]. In Figure 17, by executing the first selection process, item W[1] and item W[3] are selected as items W to be received by the upper lifting device 6U, and item W[2] is selected as item W to be received by the lower lifting device 6L. Then, item W[4] is the target of the next first or second selection process. Specifically, item W[4] becomes item W[1'], item W[5] becomes item W[2'], item W[6] becomes item W[3'], and item W[7] becomes item W[4'].

[0060] 17, it is assumed that the control system C executes the first selection process or the second selection process so as to receive as many items W as possible while still receiving less than the maximum number that the upper lifting device 6U and the lower lifting device 6L can hold. Therefore, item W[1] and item W[3] are selected as the items W to be received by the upper lifting device 6U, and item W[2] is selected as the item W to be received by the lower lifting device 6L. In contrast to this configuration, for example, in at least one of the upper lifting device 6U and the lower lifting device 6L, holding the items W in consecutive order according to the delivery order may be prioritized over receiving a large number of items W. In this case, item W[1] and item W[2] are selected as the items W to be received by the upper lifting device 6U, and item W[3] becomes item W[1′], item W[4] becomes item W[2′], item W[5] becomes item W[3′], and item W[6] becomes item W[4′].

[0061] Other Embodiments (1) In the above embodiment, an example has been described in which the control system C executes the second selection process as the selection process when it is unable to execute the first selection process as the selection process. However, the present disclosure is not limited to such a configuration, and when it is unable to execute the first selection process as the selection process, the control system C may execute the first selection process to receive less than the maximum number of items W that the upper lifting device 6U and the lower lifting device 6L can hold, and the remaining items W may be subject to the next first selection process.

[0062] (2) In the above embodiment, a configuration has been described in which the Z-direction position at which the carry-out device 2 receives the article W from each of the upper lifting device 6U and the lower lifting device 6L is biased toward the lower side Z1 of the entire Z-direction area of ​​the lifting path 60. However, the present disclosure is not limited to such a configuration, and a configuration is also possible in which the Z-direction position at which the carry-out device 2 receives the article W from each of the upper lifting device 6U and the lower lifting device 6L is biased toward the upper side Z2 of the entire Z-direction area of ​​the lifting path 60. In this case, the upper side Z2 corresponds to the "first side in the vertical direction." In this case, unlike the above embodiment, the six holding patterns shown in FIG. 3 are, in order of priority, pattern 2, pattern 1, pattern 4, pattern 3, pattern 6, and pattern 5. In addition, the Z-direction position at which the discharge device 2 receives the item W from each of the upper lifting device 6U and the lower lifting device 6L can be configured so that it is not biased toward either the lower side Z1 or the upper side Z2 within the entire Z-direction area of ​​the lifting path 60.

[0063] (3) In the above embodiment, an example has been described in which the control system C executes a transfer process in which multiple items W are transferred from the upper lifting device 6U and the lower lifting device 6L to the carry-out device 2 in a predetermined transfer order. However, the present disclosure is not limited to such a configuration, and the control system C may be configured to transfer multiple items W from the upper lifting device 6U and the lower lifting device 6L to the carry-out device 2 in any order.

[0064] (4) In the above embodiment, an example has been described in which the upper lifting device 6U and the lower lifting device 6L are each capable of holding two articles W. However, the present disclosure is not limited to such a configuration, and the upper lifting device 6U and the lower lifting device 6L may each be configured to hold three or more articles W. Furthermore, in cases where the upper lifting device 6U and the lower lifting device 6L have different configurations of the article W holding portions (for example, dimensions of the holding portions), the maximum number of articles W that the upper lifting device 6U can hold (a value of 2 or more) and the maximum number of articles W that the lower lifting device 6L can hold (a value of 2 or more) may be different.

[0065] (5) In the above embodiment, the hierarchical conveying device 4 is a conveyor. However, the present disclosure is not limited to such a configuration. For example, the hierarchical conveying device 4 may be made up of transport vehicles 5 arranged on multiple levels so as to be aligned in the Z direction. In this case, the lifting transport device 6 is configured to receive the article W from the transport vehicles 5 serving as the hierarchical conveying device 4.

[0066] (6) In the above embodiment, the configuration in which the carry-out device 2 and the carry-in device 3 are conveyors has been described as an example. However, the present disclosure is not limited to such a configuration, and at least one of the carry-out device 2 and the carry-in device 3 may be a transport vehicle such as a track-guided vehicle or a trackless vehicle, a pusher that pushes out the article W, a robot arm, or the like.

[0067] (7) In the above embodiment, an example has been described in which the article transport equipment 100 includes a storage shelf 1, a carry-in device 3, and a transport vehicle 5. However, the present disclosure is not limited to such a configuration, and the article transport equipment 100 may also be configured without including at least one of these. For example, if the carry-out device 2 is used for both carry-out and carry-in depending on the state of the article transport equipment 100 at the time, the article transport equipment 100 may be configured without including a carry-in device 3 separate from the carry-out device 2. In this case, the lifting transport device 6 is used for retrieval when the carry-out device 2 is used for retrieval, and is used for storage when the carry-out device 2 is used for retrieval.

[0068] (8) Note that the configurations disclosed in the above-described embodiments can be applied in combination with configurations disclosed in other embodiments (including combinations of embodiments described as other embodiments) as long as no contradictions arise. Regarding other configurations, the embodiments disclosed in this specification are merely examples in all respects. Therefore, various modifications can be made as appropriate within the scope of the present disclosure.

[0069] [Summary of this embodiment] An outline of the article transport facility described above will now be described.

[0070] The item transport equipment comprises tiered transport devices arranged in multiple levels in a vertical line, a lifting transport device that transports items received from the tiered transport devices in a vertical direction, a discharge device that discharges the items received from the lifting transport device, and a control system that controls the tiered transport devices and the lifting transport devices, wherein the lifting transport devices comprise an upper lifting device that moves vertically along a lifting path, and a lower lifting device that moves vertically along the lifting path below the upper lifting device, and the upper lifting device and the lower lifting device are each configured to be able to hold a plurality of the items, and the control system performs a first selection process as a selection process to select the items to be received by each of the upper lifting device and the lower lifting device, such that the lowest tiered transport device among the tiered transport devices on which the items to be received by the upper lifting device are arranged is above the highest tiered transport device among the tiered transport devices on which the items to be received by the lower lifting device are arranged.

[0071] According to this configuration, when multiple items are transported from a tiered conveying device to a carry-out device by an elevator conveying device, the first selection process can be performed to prevent the vertical range in which the upper elevator device receives items from the tiered conveying device from overlapping with the vertical range in which the lower elevator device receives items from the tiered conveying device. This makes it easier to overlap the period in which the upper elevator device performs the receiving operation to receive items from the tiered conveying device with the period in which the lower elevator device performs the receiving operation to receive items from the tiered conveying device. This makes it easier to improve the efficiency of transporting items by the elevator conveying device.

[0072] Here, when the control system cannot execute the first selection process as the selection process, it is preferable that the control system executes a second selection process as the selection process, which ensures that the lowest hierarchical conveying device among the hierarchical conveying devices on which the item to be received by the upper lifting device is placed is the same as the highest hierarchical conveying device among the hierarchical conveying devices on which the item to be received by the lower lifting device is placed.

[0073] According to this configuration, when multiple items are transported from a tiered conveying device to a carry-out device by an elevator conveying device, even if the first selection process cannot be performed, the second selection process can be performed to minimize the overlap between the vertical range in which the upper elevator device receives items from the tiered conveying device and the vertical range in which the lower elevator device receives items from the tiered conveying device. This makes it relatively easy to overlap the period in which the upper elevator device performs the receiving operation to receive items from the tiered conveying device and the period in which the lower elevator device performs the receiving operation to receive items from the tiered conveying device. This makes it easier to improve the efficiency of transporting items by the elevator conveying device.

[0074] As described above, in a configuration in which the control system executes the second selection process as the selection process if it is unable to execute the first selection process as the selection process, if the control system is unable to receive the maximum number of items that the upper lifting device and the lower lifting device can hold in both the first selection process and the second selection process, it is preferable that the control system executes the first selection process or the second selection process to receive fewer than the maximum number of items that the upper lifting device and the lower lifting device can hold, and make the remaining items the subject of the next first selection process or second selection process.

[0075] According to this configuration, the efficiency of transporting items by the lifting and conveying device is increased by performing the first selection process and the second selection process so as to receive as many items as possible as possible, and if the upper lifting and conveying device cannot receive the maximum number of items it can hold, the remaining items can be made the subject of the next first selection process or second selection process, thereby ensuring that the necessary items are transported to the carry-out device.

[0076] In each of the above configurations, the discharge device is configured to receive the items from each of the upper lifting device and the lower lifting device at a predetermined vertical position, the control system is configured to execute a delivery process to deliver the multiple items from the upper lifting device and the lower lifting device to the discharge device in a predetermined delivery order, and it is preferable that the control system executes the selection process so that the items are held in each of the upper lifting device and the lower lifting device in a consecutive order according to the delivery order.

[0077] According to this configuration, in the transfer process, all of the items held by one of the upper and lower lifting devices are transferred to the carry-out device, and then all of the items held by the other of the upper and lower lifting devices are transferred to the carry-out device, so that the items can be transferred to the carry-out device in a predetermined transfer order. Therefore, even if the carry-out device is configured to receive items at a predetermined vertical position, the number of lifting and lowering operations of the upper and lower lifting devices in the transfer process can be kept low. This makes it easy to improve the efficiency of transporting items by the lifting and conveying device.

[0078] As described above, in a configuration in which the control system performs the selection process so that the items are held in each of the upper lifting device and the lower lifting device in consecutive order according to the delivery order, it is preferable that the vertical positions at which the discharge device receives the items from each of the upper lifting device and the lower lifting device are biased toward one side of the entire vertical area of ​​the lifting path, that is, a first vertical side, and that the control system, in the selection process, holds the item that is later in the delivery order from the upper lifting device or the lower lifting device that is positioned on the first vertical side.

[0079] According to this configuration, the lifting device with a narrower vertical lifting range from the carry-out device will deliver the item to the carry-out device later than the lifting device with a wider lifting range. Therefore, the lifting device with the wider lifting range can finish delivering the item first and move on to receive the next item. In other words, the lifting device that is likely to have to move a longer vertical distance to receive the next item can start moving first. This makes it easier to improve the efficiency of transporting items using the lifting transport device.

[0080] It is sufficient for the article transport facility according to the present disclosure to achieve at least one of the above-described effects. [Explanation of symbols]

[0081] 2: Unloading device 4: Layered conveyor 6: Lifting and transporting device 6U: Upper lifting device 6L: Lower lifting device 60: Elevation route 100: Goods transport equipment C: Control system W:Goods Z: Z direction (vertical direction) Z1: Lower side (first side in vertical direction) Z2: Upper side

Claims

1. a tiered conveying device arranged in a plurality of tiers so as to be aligned in a vertical direction; an elevating conveying device that conveys the article received from the level conveying device in a vertical direction; a carrying-out device that carries out the article received from the lifting and conveying device; a control system for controlling the level conveying device and the lifting conveying device, the lifting and transporting device includes an upper lifting device that moves up and down along a lifting path, and a lower lifting device that moves up and down along the lifting path below the upper lifting device, the upper lifting device and the lower lifting device are each configured to hold a plurality of the articles; The control system performs a first selection process as a selection process to select the items to be received by each of the upper lifting device and the lower lifting device, such that the lowest hierarchical conveying device on which the item to be received by the upper lifting device is placed is above the highest hierarchical conveying device on which the item to be received by the lower lifting device is placed.

2. 2. The item transport equipment of claim 1, wherein, when the first selection process cannot be performed as the selection process, the control system performs a second selection process as the selection process, in which the lowest hierarchical transport device among the hierarchical transport devices on which the item to be received by the upper lifting device is placed is the same as the highest hierarchical transport device among the hierarchical transport devices on which the item to be received by the lower lifting device is placed.

3. 3. The item transport equipment of claim 2, wherein, if the control system is unable to receive the maximum number of items that the upper lifting device and the lower lifting device can hold in both the first selection process and the second selection process, it executes the first selection process or the second selection process to receive fewer items than the maximum number that the upper lifting device and the lower lifting device can hold, and subjects the remaining items to the next first selection process or the second selection process.

4. the discharge device is configured to receive the article from each of the upper lifting device and the lower lifting device at a predetermined position in the vertical direction; the control system is configured to execute a delivery process for delivering the plurality of articles from the upper lifting device and the lower lifting device to the carry-out device in a predetermined delivery order; The item transport equipment according to any one of claims 1 to 3, wherein the control system executes the selection process so that the items are held in each of the upper lifting device and the lower lifting device in a consecutive order according to the delivery order.

5. a vertical position at which the carry-out device receives the article from each of the upper lifting device and the lower lifting device is biased toward a first vertical side, which is one side of the vertical direction, within the entire vertical area of ​​the lifting path; The item transport equipment of claim 4, wherein the control system, in the selection process, causes the upper lifting device or the lower lifting device located on the first side in the vertical direction to hold the item that is later in the delivery order.

Images