Automated warehouse

Abstract

Provided is an automated warehouse in which the total length of a roller conveyor for conveying two cargoes on a lifting / lowering table can be shortened. An automatic warehouse 1 according to the present invention comprises a rack 2 that has a plurality of shelves 14, a conveyance trolley 4, and lifting / lowering conveyance devices 10, 12 that are for loading and unloading cargo W between the shelves via or not via buffer conveyors 24, 38, wherein: the lifting / lowering conveyance devices comprise lifting / lowering tables 20, 30; the lifting / lowering tables comprise a first roller conveyor 34 and a second roller conveyor 36 and can have two cargoes placed thereon; the first roller conveyor 34 comprises at least first rollers 52; the second roller conveyor 36 comprises at least second rollers 54 having a diameter or frictional force greater than that of the first rollers; the first rollers 52 are disposed on the downstream side of at least the first roller conveyor 34; and the second rollers 54 are disposed on the upstream side of at least the second roller conveyor 36.

Description

automated warehouse

[0001] The present invention relates to an automated warehouse, and more particularly to an automated warehouse equipped with a rack having a plurality of shelves, transport vehicles that move between the shelves in the rack, and an elevator transport device for loading and unloading cargo between the shelves.

[0002] Patent Document 1 discloses an automated warehouse in which two packages are transported by a conveyor on a lifting platform. Patent Document 2 discloses an automated warehouse in which multiple packages are transported by a conveyor on a lifting platform.

[0003] JP 2022-094210 A JP 2021-187625 A

[0004] There has been a demand for reducing the lifting load of a vertically ascending / descending platform. The inventors of the present invention have noticed that the lifting load can be reduced by shortening the overall length (conveyor length) of the conveyor that is provided on the platform and that transports cargo.

[0005] In a motor-driven roller conveyor, even after the rollers are stopped to stop the load, the load tends to flow downstream due to inertia, depending on the transport speed and weight of the load. Therefore, it is necessary to ensure a margin for the flow. In particular, in a roller conveyor on a lifting platform, it is difficult to shorten the overall length in order to ensure the margin. To address this issue, it is conceivable to reduce the margin for the flow by controlling the deceleration of the load using a deceleration sensor or the like, thereby reducing the overall length of the conveyor. However, in a conveyor that transports two loads (called a twin birch conveyor), the upstream roller conveyor and the downstream roller conveyor are not linked, and therefore, there is a problem in that deceleration and stop control using a deceleration sensor or the like is not possible.

[0006] Therefore, the present invention has been made to solve the above-mentioned problems, and has an object to provide an automated warehouse that can shorten the overall length of a roller conveyor that transports two packages on a lifting platform.

[0007] In order to achieve the above object, the present invention provides an automated warehouse comprising a rack having a plurality of shelves, transport carts that move between each shelf in the rack, and a lifting and transporting device for transporting cargo between each shelf, wherein the lifting and transporting device comprises a lifting platform that moves up and down, the lifting platform comprising an upstream roller conveyor arranged upstream in the direction of cargo transport and a downstream roller conveyor arranged downstream in the direction of cargo transport, and is capable of carrying two cargoes, the upstream roller conveyor comprises a first roller, and the downstream roller conveyor comprises a second roller that has a larger diameter or greater frictional force than the first roller, the first roller is arranged at least downstream of the upstream roller conveyor, and the second roller is arranged at least upstream of the downstream roller conveyor.

[0008] According to the present invention configured as described above, even if the trailing end of a load conveyed to the downstream roller conveyor catches on the first roller of the upstream roller conveyor (located downstream of the upstream roller conveyor), the first roller has a relatively small diameter or low friction, so the downstream roller conveyor does not interfere with the load. Furthermore, the second roller of the downstream roller conveyor has a relatively large diameter or high friction, so the load can be reliably positioned (e.g., the second roller can control deceleration and stop). Therefore, the action of the first roller of the upstream roller conveyor and the action of the second roller of the downstream roller conveyor minimizes the predetermined allowance length (allowing for load flow) that was previously set in the load conveying direction. As a result, the overall length of the roller conveyor conveying two loads on the lifting platform can be shortened. Furthermore, the weight of the lifting platform can be reduced by the shortened overall length.

[0009] In addition, in the present invention, preferably, both the upstream roller conveyor and the downstream roller conveyor include a first roller and a second roller having a larger diameter or greater frictional force than the first roller, and in both the upstream roller conveyor and the downstream roller conveyor, the first roller is located downstream and the second roller is located upstream. According to the present invention configured in this way, it is possible to minimize the impact on the loading and unloading of cargo onto and from the lifting platform.

[0010] In the present invention, preferably, both the upstream roller conveyor and the downstream roller conveyor are provided with a deceleration sensor for slowing down the conveying speed of the goods being conveyed by the upstream roller conveyor and the downstream roller conveyor, and a stop sensor for stopping the goods whose conveying speed has slowed down. According to the present invention configured in this way, in addition to the action of the first roller of the upstream roller conveyor and the action of the second roller of the downstream roller conveyor, the deceleration sensor and the stop sensor are used to control the deceleration and stop of the goods, thereby reliably positioning the goods, and thereby more reliably minimizing the predetermined allowance length (allowance length for goods flow) that has conventionally been set in the goods conveying direction.

[0011] In the present invention, the downstream roller conveyor preferably includes at least a deceleration sensor for decelerating the load conveyed by the downstream roller conveyor, and the position of the deceleration sensor and the arrangement of the first and second rollers are set so that, in a side view, the distance from the position of the deceleration sensor on the downstream roller conveyor to the boundary between the first and second rollers on the upstream roller conveyor is greater than a predetermined maximum length of the load in the conveying direction. According to the present invention configured in this manner, the maximum length of the load conveyed is shorter than the distance from the position of the deceleration sensor on the downstream roller conveyor to the boundary between the first and second rollers of the upstream roller conveyor. Therefore, when the load conveyed by the downstream roller conveyor begins to decelerate due to the deceleration sensor, the trailing end of the load rests on the first roller of the upstream roller conveyor, which has a relatively small diameter or low frictional force, thereby preventing the upstream roller conveyor from interfering with the load. This more reliably and accurately controls the deceleration and stop of the load by the deceleration sensor on the downstream roller conveyor.

[0012] In the present invention, the elevator conveying device preferably includes an entry elevator conveying device for transporting cargo onto each shelf of the rack and an outgoing elevator conveying device for transporting cargo from each shelf of the rack. In the entry elevator conveying device, the upstream roller conveyor is disposed farther from the rack and the downstream roller conveyor is disposed closer to the rack. In the outgoing elevator conveying device, the upstream roller conveyor is disposed closer to the rack and the downstream roller conveyor is disposed farther from the rack. In both the entry elevator conveying device and the outgoing elevator conveying device, the first roller is disposed downstream and the second roller is disposed upstream. According to this configuration, the same elevator conveying device can be used for both entry and outgoing. For example, roller conveyor assemblies having the same structure constituting the upstream or downstream roller conveyor can be used as the upstream and downstream roller conveyors, as appropriate.

[0013] According to the present invention, the overall length of a roller conveyor that transports two loads on a lifting platform can be shortened.

[0014] Fig. 6 is a side view showing a schematic configuration of an automated warehouse according to an embodiment of the present invention; Fig. 6 is a plan view partially showing a schematic configuration of an automated warehouse according to an embodiment of the present invention; Fig. 6 is a side view showing a schematic configuration of an upstream roller conveyor and a downstream roller conveyor on a lifting platform of a lifting and transporting device according to this embodiment; Fig. 6 is a plan ... a modified embodiment of this embodiment; Fig. 6 is a diagram for explaining the action and effect of the lifting platform of the lifting and transporting device according to this embodiment, Fig. 6(A) is a side view showing a schematic configuration of the lifting platform of the lifting and transporting device according to this embodiment, and Fig. 6(B) is a side view showing a schematic configuration of a lifting platform of a conventional technology as a comparative example.

[0015] Next, an automated warehouse according to an embodiment of the present invention will be described with reference to the accompanying drawings.

[0016] First, the overall configuration of an automated warehouse according to an embodiment of the present invention will be described with reference to Figures 1 and 2. Figure 1 is a side view showing a schematic configuration of an automated warehouse according to an embodiment of the present invention, and Figure 2 is a plan view showing a part of the schematic configuration of an automated warehouse according to an embodiment of the present invention. Note that in the following description, in each drawing, the direction indicated by arrow Y is the basic transport direction of packages, the direction indicated by arrow X is the width direction of the automated warehouse or conveyor which is perpendicular to the transport direction Y, and the direction indicated by arrow Z is the vertical direction.

[0017] First, as shown in Fig. 1, the automated warehouse 1 according to this embodiment includes a pair of racks 2, a plurality of transport carts 4 (hereinafter simply referred to as "carts"), a storage station 6, a shipping station 8, a storage lifting and transporting device 10, and a shipping lifting and transporting device 12. As shown in Fig. 2, the pair of racks 2 and the carts 4 constitute a unit 5, and the automated warehouse 1 has a plurality of units 5.

[0018] Next, as shown in Fig. 1, the luggage W is carried into the storage station 6 from a carry-in conveyor (not shown) and then carried into each unit 5 (see Fig. 2) via a storage elevator 10. The luggage W from each unit 5 is then carried out from the delivery station 8 to an unloading conveyor (not shown) via an unloading elevator 12. The destination of the unloading conveyor is a sorting area where the luggage W are collected by destination and shipped by truck or the like, or a picking area where products are picked from the luggage W. For ease of explanation, in Figure 1, the receiving side devices such as the receiving station 6 and the receiving lifting and conveying device 10 are shown on one side of the automated warehouse 1, and the unloading side devices such as the unloading station 8 and the unloading lifting and conveying device 12 are shown on the other side of the automated warehouse 1. However, as shown in Figure 2, the receiving side devices such as the receiving lifting and conveying device 10 and the unloading side devices such as the unloading lifting and conveying device 12 are arranged adjacent to each other in the X direction of the automated warehouse 1.

[0019] Next, the rack 2 will be described. As shown in Fig. 1, the rack 2 has a plurality of shelf levels 14, and packages are stored on each shelf level 14, or packages stored on each shelf level 14 are removed from each shelf level 14. Each shelf level 14 of the rack 2 extends in the Y direction and has a plurality of openings 16 along the Y direction. Each opening 16 is a unit of shelf level 14 on which packages W are placed, and all have the same length in the Y direction. The shelf levels 14 are arranged on both sides of the cart 4 and the rail 15 in the X direction.

[0020] Each opening 16 is large enough to store a plurality of packages W. The openings 16 may be separate or integral, and for example, a single shelf board that constitutes a shelf 14 may be appropriately divided to form a plurality of openings 16 on the shelf 14. The packages W are cases, trays, cardboard boxes, foldable containers, etc., and contain, for example, products.

[0021] Next, the dolly 4 will be described. As shown in Figures 1 and 2, the multiple dollies 4 (an example of a storage / retrieval dolly) are shuttle dollies, each of which travels back and forth on a rail 15 extending linearly in the Y direction at a height corresponding to each shelf level 14. The dolly 4 transports, for example, one piece of luggage W at a time. The dolly 4 also has a transfer device 18, which enables the dolly 4 to transfer the luggage W between the opening 16 of the corresponding shelf level 14. The transfer device 18 is, for example, a rear hook type. Note that the transfer device is not limited to the rear hook type, and other types of devices may be used.

[0022] Next, the lifting and conveying devices 10, 12 will be described. First, as shown in FIG. 1 , the receiving lifting and conveying device 10 includes a lifting platform 20 disposed between the rack 2 and the receiving station 6. In this embodiment, the lifting platform 20 includes a lifting platform conveyor 22 capable of carrying two packages W along the conveying direction (Y direction). The lifting platform conveyor 22 in this embodiment is a so-called roller conveyor, and includes a first roller conveyor (upstream roller conveyor) 34 and a second roller conveyor (downstream roller conveyor) 36 as shown in FIGS. 3 and 4 (described later). The lifting platform conveyor 22 transfers packages W between the receiving station 6 and a receiving conveyor 24 (described later).

[0023] Next, the receiving elevator conveying device 10 is equipped with a known elevator mechanism 28 that raises and lowers the elevator platform 20 along the support columns 26 and stops it at any shelf position of the multiple shelves 14. In addition, each shelf 14 is provided with an entrance conveyor 24 at a portion adjacent to the receiving elevator conveying device 10 in the Y direction. Therefore, the elevator platform conveyor 22 and the entrance conveyor 24 operate in conjunction with each other to transfer the cargo W. The entrance conveyor 24 functions as a buffer conveyor for storing cargo. The entrance conveyor 24 is, for example, a belt conveyor.

[0024] 1 and 2, the outgoing lifting and transporting device 12 includes a lifting platform 30 disposed between the rack 2 and the outgoing station 8. In this embodiment, the lifting platform 30 includes a lifting platform conveyor 32 capable of loading two packages W along the transport direction (Y direction). The lifting platform conveyor 32 in this embodiment is a roller conveyor having the same structure as the above-described receiving-side lifting platform conveyor 22, and includes a first roller conveyor 34 and a second roller conveyor 36 as shown in FIGS. 3 and 4, which will be described later. The lifting platform conveyor 32 transfers packages W between the outgoing station 8 and an outgoing conveyor 38, which will be described later.

[0025] 3 and 4 described below will mainly explain the outgoing-side platform conveyor 32, but in this embodiment, the outgoing-side platform conveyor 32 and the receiving platform conveyor 22 have the same structure, and therefore, for convenience of explanation, the same reference numerals are used to designate the same components on the receiving and outgoing sides. In this embodiment, as will be described later, the outgoing-side platform conveyor 32 and the receiving platform conveyor 22 are oriented in opposite directions with respect to the conveying direction (Y direction) on the receiving and outgoing sides, so that they function as receiving and outgoing conveyors, respectively.

[0026] Next, the outgoing lifting and conveying device 12 is equipped with a known lifting mechanism 42 that raises and lowers the lifting platform 30 along the support columns 40 and stops it at any shelf position of the multiple shelves 14. In addition, each shelf 14 is provided with an outgoing conveyor 38 at a portion adjacent to the outgoing lifting and conveying device 12 in the Y direction. Therefore, the lifting platform conveyor 32 and the outgoing conveyor 38 operate in conjunction with each other to transfer the cargo W. The outgoing conveyor 38 functions as a buffer conveyor for storing cargo. The outgoing conveyor 38 is, for example, a belt conveyor.

[0027] Next, the receiving station 6 and the outgoing station 8 will be described. First, as shown in Figures 1 and 2, the receiving station 6 is arranged on both sides of the rack 2 (only one side is shown in Figure 1). The receiving station 6 receives the cargo W to be stored in the rack 2 from an infeed conveyor (not shown). The receiving station 6 has a station conveyor 6a. Next, the outgoing station 8, like the receiving station 6, is arranged on both sides of the rack 2 (only one side is shown in Figure 1). The outgoing station 8 receives the cargo W that has been carried out from the rack 2. The outgoing station 8 has a station conveyor 8a.

[0028] As shown in FIG. 2 , the storage stations 6 and the shipping stations 8 are arranged adjacent to each other in the X direction of the automated warehouse 1, and accordingly, the storage lifting platform 20, the storage conveyor 24, the shipping lifting platform 30, and the shipping conveyor 38 are also arranged adjacent to each other in the X direction in accordance with the arrangement of the storage stations 6 and the shipping stations 8.

[0029] The automated warehouse 1 according to this embodiment also includes a controller 44 connected by wire or wirelessly to the receiving elevator conveying device 10 and the outgoing elevator conveying device 12. In this embodiment, this controller 44 is a device that individually controls the transport operations of the cargo by the receiving-side elevator conveyor 32 and the outgoing-side elevator conveyor 32 (first roller conveyor 34, second roller conveyor 36).

[0030] The controller 44 is connected to the receiving lifting and conveying device 10 and the outgoing lifting and conveying device 12, as well as to the receiving station 6, the outgoing station 8, the plurality of carts 4, the plurality of receiving conveyors 24, and the plurality of outgoing conveyors 38, and is also a device that manages the storage, entry and exit of the luggage W in the automated warehouse 1. The controller 44 is composed of a processing device (circuit) that is one or more processors (typically a CPU), memory (ROM, RAM, etc.) that stores various programs, and a computer that is equipped with input / output devices, etc.

[0031] An example of a loading / unloading operation of a load controlled by the controller 44 will be described. For example, in a loading operation, the lifting platform 20 of the loading lifting conveying device 10 moves to the position of the station conveyor 6a of the loading station 6, and then, in this example, continuously transports two loads W from the station conveyor 6a to the loading lifting platform conveyor 22. Next, the lifting platform 20 moves up and down to a position corresponding to the shelf 14 (managed by the controller 44) where the loads W are to be loaded, and continuously transports the two loads W from the lifting platform conveyor 22 to the loading conveyor 24. Note that only one load W may be transported. Next, the cart 4 moves to the loading conveyor 24 and loads one load W, and then travels in the Y direction to lower the load W into the target opening 16 of the shelf 14.

[0032] Meanwhile, in the outgoing operation, the carriage 4 of the shelf 14 on which the cargo W to be outgoing (managed by the controller 44) is stored transfers the cargo W onto the carriage 4 at the target entrance 16, and then transports the cargo W to the outgoing conveyor 38. Meanwhile, the lifting platform 30 of the outgoing lifting transport device 12 is raised and lowered, and the lifting platform 30 is stopped at a position corresponding to the shelf 14 on which the cargo W to be outgoing is stored. The outgoing conveyor 38 also functions as a buffer conveyor, and in this example, two cargoes are transported consecutively from the outgoing conveyor 38 to the lifting platform conveyor 32. It is also possible to transport only one cargo W. Next, the lifting platform 30 is raised and lowered, and the cargoes W are transported two at a time to the outgoing station conveyor 8a.

[0033] Next, the configuration of the platform conveyor 32 provided on the outgoing-side platform 30 and the incoming-side platform 20 according to this embodiment will be described with reference to Figures 3 and 4. Figure 3 is a side view showing the schematic configuration of the upstream and downstream roller conveyors on the platform of the elevator transport device according to this embodiment, and Figure 4 is a plan view showing the schematic configuration of the upstream and downstream roller conveyors on the platform of the elevator transport device according to this embodiment. Note that in the following, Figures 3 and 4 will be described as showing the platform conveyor 32 provided on the outgoing-side platform 30. In this embodiment, the incoming-side platform conveyor 22 has the same structure as the outgoing-side platform conveyor 32, so a description thereof will be omitted here.

[0034] In the following description, the terms "upstream side" and "downstream side" refer to the upstream side and downstream side in the transport direction of the luggage W on the platform conveyor 32 (22). For example, as shown in FIGS. 1 and 2, the outgoing-side platform conveyor 32 has a rack 2 and an outgoing conveyor 38 provided upstream thereof, and an outgoing station 8 provided downstream thereof. The incoming-side platform conveyor 22 is provided in the opposite direction in the Y direction to the outgoing-side platform conveyor 32. That is, as can be understood from FIG. 1 and the above description, the incoming-side platform conveyor 22 has an incoming station 6 provided upstream thereof, and a rack 2 and an ingoing conveyor 24 provided downstream thereof.

[0035] Next, as shown in Figures 3 and 4, the platform conveyor 32 (22) has a predetermined conveying direction indicated by the arrow in the figures, and transports packages W from upstream to downstream along this conveying direction. Here, W11, W12, and W13, shown by phantom lines in Figure 3, respectively indicate packages with a predetermined maximum length in the conveying direction among packages that can be stored in the automated warehouse 1, and W21 and W22 indicate packages with a predetermined minimum length in the conveying direction. For convenience of explanation, W11, W12, and W13 are shown overlapping each other, but in reality, two packages are placed on the platform conveyor 32 (22) so as not to collide with each other.

[0036] 3 and 4, the platform conveyor 32 includes a first roller conveyor (upstream roller conveyor) 34 on the upstream side and a second roller conveyor (downstream roller conveyor) 36 on the downstream side. The first roller conveyor 34 includes upstream rollers (second rollers) 50 arranged relatively upstream of the first roller conveyor 34 and downstream rollers (first rollers) 52 arranged relatively downstream. In the illustrated example, the upstream rollers 50 include a total of ten rollers, and the downstream rollers 52 include a total of three rollers. Meanwhile, the second roller conveyor 36 includes upstream rollers (second rollers) 54 arranged relatively upstream of the second roller conveyor 36 and downstream rollers (first rollers) 56 arranged relatively downstream. In the illustrated example, the upstream rollers 54 include a total of ten rollers, and the downstream rollers 56 include a total of three rollers.

[0037] In this embodiment, in the first roller conveyor 34 and the second roller conveyor 36, each upstream roller 50, 54 is a roller in which a sleeve-shaped resin tube member 58 is fitted onto the outer circumferential surface of a metal roller, and each downstream roller 52, 56 is a metal roller 60. In this embodiment, using such a resin tube member 58, the diameter of the upstream rollers 50, 54 is made larger than the diameter of the downstream rollers 52, 56, which are also metal rollers 60. Also, in this embodiment, the downstream metal rollers 60 (52, 56) that do not have a resin tube member fitted thereto and the upstream metal rollers (50, 54) that have a resin tube member 58 fitted thereto are made of the same metal rollers having the same diameter and material.

[0038] In this example, a PVC tube 58 having a thickness of approximately 2 mm is used as the resin tube member 58, so that in both the first roller conveyor 34 and the second roller conveyor 36, the load support surface of the roller into which the resin tube member 58 is fitted is positioned approximately 2 mm higher than the load support surface of the downstream rollers 52, 56 (the load support surface formed at the apex of each roller in the cross-sectional view shown in Figure 3).

[0039] As shown in FIG. 4, each of the rollers 50, 52, 54, 56 is supported at both ends by a pair of platform frames 62 provided on each side of the platform conveyor 32 (22) in the width direction.

[0040] 3 and 4, the upstream roller 50 of the first roller conveyor 34 and the upstream roller 54 of the second roller conveyor 36 are each provided with a drive roller 64, 66 incorporating a motor (not shown). The remaining rollers 50, 52 of the first roller conveyor 34 are driven rollers connected by a belt (not shown) to the drive roller 64, and the remaining rollers 54, 56 of the second roller conveyor 36 are driven rollers connected by a belt (not shown) to the drive roller 66. The operations of the first roller conveyor 34 and the second roller conveyor 36 (driving operations of the rollers to transport packages W) are individually controlled by the controller 44 based on package detection signals from sensors 70, 72 (see FIGS. 3 and 4) of the first roller conveyor 34 and package detection signals from sensors 76, 78 of the second roller conveyor 36, which will be described later.

[0041] 3 and 4, the first roller conveyor 34 includes a stop sensor 70 for stopping the conveyance of a package (see package W13 in FIG. 3) conveyed on the upstream rollers 50 and the downstream rollers 52, a deceleration sensor 72 provided at a predetermined position upstream thereof for reducing the conveyance speed of the package conveyed on the upstream rollers 50, and a package sensor 74 for detecting the protrusion of the rear end of the package upstream from the first roller conveyor 34. Similarly, the second roller conveyor 36 includes a stop sensor 76 for stopping the conveyance of a package (see package W11 in FIG. 3) conveyed on the upstream rollers 54 and the downstream rollers 56, a deceleration sensor 78 provided at a predetermined position upstream thereof for reducing the conveyance speed of the package (see package W12 in FIG. 3) conveyed on the upstream rollers 54, and a package sensor 80 for detecting the protrusion of the front end of the package downstream from the second roller conveyor 36.

[0042] These sensors (70, etc.) are photoelectric sensors having a light source, a light receiver, and a reflector, which are each attached to the platform frame 62 (see FIG. 4 ). As shown in FIG. 4 , the optical axis O (indicated by a dashed line) of each sensor (70, etc.) is perpendicular to the conveying direction (Y direction) of the first roller conveyor 34 and the second roller conveyor 36 and extends horizontally. When the light emitted from the light source is blocked by a package W and is not reflected by the reflector and received by the receiver, the controller 44 determines that a package W has been detected and transmits a predetermined signal to the controller 44. In the configuration shown in FIGS. 3 and 4 , the stop sensors 70, 76, deceleration sensors 72, 78, and package overload detection sensor 80 transmit detection signals when the front end of a package W being conveyed interrupts the optical axis O. The package overload detection sensor 74 transmits a detection signal when the rear end of a package W being conveyed interrupts the optical axis O.

[0043] 3 and 4, the relationship between the position of the deceleration sensor 78 provided on the second roller conveyor 36, the boundary position between the upstream rollers 50 and downstream rollers 52 on the first roller conveyor 34, and the length of the "package with the longest length in the conveying direction" will be described. More precisely, the position of the deceleration sensor 78 is determined by the position of its optical axis O, and the boundary position between the upstream rollers 50 and downstream rollers 52 is determined by the midpoint between the upstream roller 50 located furthest downstream and the downstream roller 52 located furthest upstream. In this embodiment, as shown in FIGS. 3 and 4, the deceleration sensor 78, the upstream rollers 50, and the downstream rollers 52 are positioned so that the distance Lr from the position of the deceleration sensor 78 provided on the second roller conveyor 36 to the boundary position between the upstream rollers 50 and downstream rollers 52 on the first roller conveyor 34 is greater than the length Lw of the package with the longest length in the conveying direction (see W12).

[0044] The effect of the dimensional relationship between the distance Lr and the length Lw will be described below in conjunction with the operation (baggage conveying speed) of the first roller conveyor 34 and the second roller conveyor 36. In this embodiment, when the deceleration sensor 78 detects the leading end of the baggage W12 in the second roller conveyor 36, the controller 44 controls the rotational speed of the drive roller 66 (see FIG. 3) of the second roller conveyor 36 to reduce the baggage conveying speed from the normal operation speed V1 to a predetermined conveying speed V2 that is lower than the normal operation speed V1. Meanwhile, when the upstream first roller conveyor 34 is conveying a bag (when the deceleration sensor 72 does not detect a bag), the drive roller 64 and the other driven rollers 50 and 52 are driven at a rotational speed sufficient to achieve the normal operation speed V1. In the second roller conveyor 36, the upstream roller 54 with the high-friction resin tube member 58 primarily conveys the baggage (W12).

[0045] In this case, since the distance Lr is greater than the maximum package length Lw, when the package is detected by the deceleration sensor 78, the rear end of the package (W12) on the second roller conveyor 36 is positioned on the downstream roller 52, which is a metal roller of the first roller conveyor 34, and is not positioned on the upstream roller 50. As described above, the diameter of the downstream roller 52 is smaller than the diameter of the upstream roller 50, and the frictional force against the package is also lower since no plastic tube member is provided.

[0046] Therefore, even if the conveying speed V2 of the second roller conveyor 36 is lower than the conveying speed V1 of the first roller conveyor 34 and the rear end of the package (W12) is hanging on the first roller conveyor 34, the rear end of the package (W12) is hanging on the downstream roller 52 which has a small diameter and low frictional force, so that the downstream roller 52 can be prevented from strongly driving the rear end of the package W12 and disrupting the behavior of the package or pushing the package (W12) from behind. Therefore, the controller 44 can individually control the drive rollers 64, 66 so as to achieve both the deceleration of the downstream package (W12) and the normal conveyance of the upstream package.

[0047] Furthermore, when the stop sensor 76 detects the leading end of a package being transported at the transport speed V2 (see package W11), the controller 44 stops the rotation of the drive roller 66. After the rotation of the drive roller 66 is stopped, package W11 moves slightly downstream due to its inertial force (coast) and then stops. The automated warehouse 1 according to this embodiment is designed so that packages moving due to their inertia will stop upstream of the package jam sensor 80 based on the expected size and weight of the package. As shown in FIG. 6A (described later), the platform conveyor 32 (22) has a distance Ls set to allow for the amount of movement due to inertia. Meanwhile, in this embodiment, a package jam detection sensor 80 is provided in case a package overhangs the platform conveyor 32 (22). When the package jam detection sensor 80 detects a package, the controller 44 temporarily stops operation of the automated warehouse 1.

[0048] The control of the transport speed of the luggage using the deceleration sensor 78 and the stop sensor 76 in the second roller conveyor 36 as described above is similar to that in the first roller conveyor 34, and therefore a description thereof will be omitted here.

[0049] Next, a modification of this embodiment will be described. First, the thickness of the resin tube member 58 described above is not limited to 2 mm, but may be other thicknesses, such as 1 to 3 mm. Furthermore, the resin is not limited to the PVC material described above, and may include plastic or rubber, as long as it is a material that increases friction. Furthermore, the diameter of the upstream rollers 50, 54 may be larger than the diameter of the downstream rollers 52, 56 so as to obtain the difference in load support surface height between the upstream rollers 50, 54 and the downstream rollers 52, 56 (2 mm in the above example). In this case, for example, the diameter of the upstream rollers may be 4 to 6 mm larger than the diameter of the downstream rollers. In this case, the upstream rollers 50, 54 and the downstream rollers 52, 56 may all be made of the same material (for example, metal).

[0050] Furthermore, the upstream rollers 50, 54 and the downstream rollers 52, 56 may have the same diameter, and one of the upstream rollers 50, 54 or the downstream rollers 52, 56 may be subjected to a predetermined surface treatment or coated with a film-like substance so that the frictional force on the surface of the upstream rollers 50, 54 is greater than the frictional force on the surface of the downstream rollers 52, 56. The surface treatment can be adjusted, for example, by adjusting the average roughness of the surface, by reducing the average roughness to reduce the frictional force and by increasing the average roughness to increase the frictional force. The film-like substance may be a substance that reduces frictional force (such as a silicon-containing substance) or a substance that increases frictional force (such as a resinous substance containing rubber).

[0051] As a further modification, as shown in Figure 5, an endless belt 82 may be looped around each of the upstream rollers 50 of the first roller conveyor 34 and the upstream rollers 54 of the second roller conveyor 36, thereby effectively increasing the (apparent) diameter of the rollers and increasing frictional force. In this case, the upstream rollers 50, 54 are made of metal, and the resin tube member 58 described above is not provided, with the endless belt 82 looped around the most upstream and most downstream rollers. The material of the endless belt 82 may be any material used in known transport conveyors.

[0052] Next, the effects of the structure of the platform conveyor 32 (22) of this embodiment and its modified examples will be described with reference to FIG. 6 . FIG. 6 is a diagram illustrating the effects of the platform of the lifting and transporting device of this embodiment. FIG. 6(A) is a side view showing the schematic configuration of the platform of the lifting and transporting device of this embodiment, and FIG. 6(B) is a side view showing the schematic configuration of a conventional platform as a comparative example. First, as shown in FIG. 6(A), in this embodiment, the overall length (also referred to as the conveyor length) of the platform conveyor 32 (22) is a predetermined length La. This length La depends on the amount of movement of the load due to inertia, as described above. In the platform conveyor 32 (2) of this embodiment, as shown in FIG. 6(A), a distance Ls is set to allow for the amount of movement due to inertia. That is, a margin length is set downstream from the deceleration sensor 78 to allow for movement due to inertia. In this embodiment, as described above, the upstream rollers 50, 54 are fitted with resin tube members 58 to increase their diameter and increase the frictional force, and further, the deceleration of the luggage is controlled in advance using the deceleration sensor 72, so that the amount of luggage movement (allowable amount) Ls due to inertia can be suppressed.

[0053] On the other hand, Figure 6(B) shows a conventional platform conveyor 132 (122) having a first roller conveyor 134 and a second roller conveyor 136. These roller conveyors 134, 136 all have the same diameter metal rollers 160, and no deceleration sensors are used. Instead, stop sensors 170, 176 control the deceleration and stopping of the cargo, and the conveying operations of the first roller conveyor 134 and the second roller conveyor 136 are controlled individually. Note that cargo overhang detection sensors 174, 180 have been provided as in the past to detect cargo overhanging the platform conveyor 132 (122).

[0054] As can be seen by comparing Figures 6(A) and 6(B), in the conventional platform conveyor 132 (122), the load movement amount (allowable amount) Lsc due to inertia is greater than the load movement amount (allowable amount) Ls of the present embodiment, and accordingly, the overall length (conveyor length) La of the platform conveyor 132 (122) is also greater than the overall length La of the present embodiment. In other words, in the present embodiment, as described above, the frictional force of the upstream rollers 50, 54 is increased and the deceleration of the load is controlled by the deceleration sensor 72, thereby suppressing the load movement amount (allowable amount) Ls due to inertia, and thereby making it possible to shorten the overall length La of the platform conveyor 32 (22) compared to conveyors of the prior art. Furthermore, this shortened length allows for a reduction in the lifting weight of the platform conveyor 32 (22).

[0055] Furthermore, in this embodiment, as described above, the distance Lr is set to be greater than the maximum length Lw of the luggage (see Figures 3 and 4). Therefore, even if the maximum length luggage (W12) begins to decelerate on the second roller conveyor 36, the first roller conveyor 34 can be maintained at the normal operating conveying speed. This makes it possible to more reliably transport two luggage on the platform conveyor 32 (22) and to individually control the speeds of the first roller conveyor 34 and the second roller conveyor 36.

[0056] Next, the effects of the automated warehouse 1 according to the embodiment and its modifications of the present invention will be described. First, the automated warehouse 1 according to the embodiment and its modifications includes a rack 2 having a plurality of shelves 14, transport vehicles 4 that move between the shelves in the rack 2, and lifting and transporting devices 10, 12 for carrying in and out cargo W between the shelves 14. The lifting and transporting devices 10, 12 include lifting platforms 20, 30 that move up and down. The lifting platforms 20, 30 include a first roller conveyor (upstream roller conveyor) 34 arranged upstream in the cargo transport direction and a second roller conveyor (downstream roller conveyor) arranged downstream in the cargo transport direction. The first roller conveyor 34 has a first roller (downstream roller) 52, and the second roller conveyor 36 has a second roller (upstream roller) 54 that has a larger diameter or a larger frictional force than the first roller, and the first roller 52 is arranged at least downstream of the first roller conveyor 34, and the second roller 54 is arranged at least upstream of the second roller conveyor 36.

[0057] According to this embodiment and its modified examples configured as described above, even if the trailing end of a package (e.g., W12) conveyed to the second roller conveyor 36 catches on the first roller 52 (located downstream of the first roller conveyor 34) of the first roller conveyor 34, the first roller 52 has a relatively small diameter or low friction, so the second roller conveyor 36 does not interfere with the package. Furthermore, the second roller 54 of the second roller conveyor 36 has a relatively large diameter or high friction, so the package can be reliably positioned (e.g., the second roller 54 can control deceleration and stopping). Therefore, the action of the first roller 52 of the first roller conveyor 34 and the action of the second roller 54 of the second roller conveyor 36 minimizes the predetermined allowance length (allowance length for package flow) (e.g., Ls) conventionally set in the package conveying direction. As a result, the overall length of the platform conveyors 22, 32 that transport two packages on the platform 20, 30 can be shortened. Furthermore, the weight of the lifting platforms 20 and 30 can be reduced by the amount of the shortened overall length.

[0058] In this embodiment and its modified examples, the first roller conveyor 34 and the second roller conveyor 36 each include a first roller 52, 56 and a second roller 50, 54 having a larger diameter or greater frictional force than the first roller, and the first roller 52, 56 is disposed downstream and the second roller 50, 54 is disposed upstream in both the first roller conveyor 34 and the second roller conveyor 36. According to this embodiment and its modified examples configured in this manner, it is possible to minimize the impact on the loading and unloading operations of luggage being loaded onto and unloaded from the lifting platforms 20, 30.

[0059] In this embodiment and its modified examples, the first roller conveyor 34 and the second roller conveyor 36 are both provided with deceleration sensors 72, 78 for slowing down the conveying speed of the goods being conveyed by the first roller conveyor 34 and the second roller conveyor 36, and stop sensors 70, 76 for stopping the goods whose conveying speed has slowed down. According to this embodiment and its modified examples configured in this manner, in addition to the action of the first roller 52 of the first roller conveyor 34 and the action of the second roller 54 of the second roller conveyor 36, the deceleration sensors 72, 78 and the stop sensors 70, 76 are used to control the deceleration and stop of the goods, thereby reliably positioning the goods, and thereby more reliably minimizing the predetermined allowance length (allowance length for goods flow) that has conventionally been set in the goods conveying direction.

[0060] In addition, in this embodiment and its variants, the second roller conveyor 36 is equipped with a deceleration sensor 78 for slowing down at least the luggage being transported by the second roller conveyor 36, and the position of the deceleration sensor 78 and the arrangement of the first roller 52 and the second roller 50 are set so that, when viewed from the side, the distance Lr from the position where the deceleration sensor 78 is provided on the second roller conveyor 36 to the boundary position between the first roller 52 and the second roller 50 on the first roller conveyor 34 is greater than the predetermined maximum length Lw of the luggage in the transport direction. According to this embodiment and its modified examples configured as described above, the maximum length Lw of the transported package is smaller than the distance from the position of the deceleration sensor 78 of the second roller conveyor 36 to the boundary between the first roller 52 and the second roller 50 of the first roller conveyor 34. Therefore, when the package transported by the second roller conveyor 36 starts to decelerate due to the deceleration sensor 78, the rear end of the package is placed on the first roller 52 of the first roller conveyor 34, which has a relatively small diameter or a small frictional force, and interference between the first roller conveyor 34 and the package (e.g., W12) can be suppressed. Therefore, the deceleration sensor 78 can more reliably and accurately control the deceleration and stop of the package in the second roller conveyor 36.

[0061] In addition, in this embodiment and its variants, the lifting and conveying device includes an in-stock lifting and conveying device 10 for transporting cargo onto each shelf 14 of the rack 2, and an out-stock lifting and conveying device 12 for transporting cargo from each shelf 14 of the rack 2, and in the in-stock lifting and conveying device 10, the first roller conveyor 34 is arranged on the side farther from the rack 2 and the second roller conveyor 36 is arranged on the side closer to the rack 2, and in the out-stock lifting and conveying device 12, the first roller conveyor 34 is arranged on the side closer to the rack 2 and the second roller conveyor 36 is arranged on the side farther from the rack 2, and in both the in-stock lifting and conveying device 10 and the out-stock lifting and conveying device 12, the first roller conveyor 34 and the second roller conveyor 36 are arranged so that the first rollers 52, 56 are arranged on the downstream side and the second rollers 50, 54 are arranged on the upstream side. According to this embodiment and its modified examples, the same structure of the lifting and conveying devices 10, 12 can be used for both storing and retrieving goods. For example, the roller conveyor assemblies of the same structure that constitute the upstream and downstream roller conveyors 34, 36 can be used to correspond to the first roller conveyor 34 and the second roller conveyor 36 as appropriate.

[0062] REFERENCE SIGNS LIST 1 Automated warehouse 2 Rack 4 Transport vehicle 6 Storage station 8 Delivery station 10 Storage lifting transport device 12 Delivery lifting transport device 14 Shelf 20 Storage-side lifting platform 22 Storage-side lifting platform conveyor 24 Storage conveyor 28 Storage-side lifting mechanism 30 Delivery-side lifting platform 32 Delivery-side lifting platform conveyor 34 First roller conveyor (first roller conveyor) 36 Second roller conveyor (second roller conveyor) 38 Delivery conveyor 42 Delivery-side lifting mechanism 44 Controller 50 Upstream roller (second roller) 52 Downstream roller (first roller) 54 Upstream roller (second roller) 56 Downstream roller (first roller) 58 PVC tube (tube member) 60 Metal roller 62 Lift platform frame 64, 66 Drive roller 70, 76 Stop sensor 72, 78 Deceleration sensor 74, 80 Load detection sensor 82 Endless belt W Load W11, W12, W13 Load (load of maximum length) W21, W22 Load (load of minimum length) Lw Maximum load length Lr Distance from deceleration sensor to boundary position of first roll and second roll La Conveyor length (total length of lift platform) Ls Margin (margin for load flow due to inertia) Lac Conveyor length (total length of lift platform) (prior art) Lsc Margin (margin for load flow due to inertia) (prior art) O Optical axis of photoelectric sensor

Claims

1. An automated warehouse comprising a rack having a plurality of shelves, each transport cart for moving on each shelf within the rack, and a lifting and conveying device for loading and unloading goods between each shelf, wherein the lifting and conveying device includes a lifting platform that moves up and down, the lifting platform includes an upstream roller conveyor disposed on the upstream side in the conveying direction of the goods and a downstream roller conveyor disposed on the downstream side in the conveying direction of the goods, and is capable of placing two goods, the upstream roller conveyor includes a first roller, and the downstream roller conveyor includes a second roller having a larger diameter or a larger frictional force than the first roller, the first roller is disposed at least on the downstream side of the upstream roller conveyor, and the second roller is disposed at least on the upstream side of the downstream roller conveyor. An automated warehouse characterized by this.

2. Both the upstream roller conveyor and the downstream roller conveyor include the first roller and the second roller having a larger diameter or a larger frictional force than the first roller. In both the upstream roller conveyor and the downstream roller conveyor, the first roller is disposed on the downstream side and the second roller is disposed on the upstream side. The automated warehouse according to claim 1.

3. Both the upstream roller conveyor and the downstream roller conveyor include a deceleration sensor for reducing the conveying speed of the goods conveyed by the upstream roller conveyor and the downstream roller conveyor, and a stop sensor for stopping the goods whose conveying speed has decreased. The automated warehouse according to claim 1 or claim 2.

4. The downstream roller conveyor includes at least a deceleration sensor for decelerating the goods conveyed by the downstream roller conveyor. In a side view, the distance from the position where the deceleration sensor is provided on the downstream roller conveyor to the boundary position between the first roller and the second roller on the upstream roller conveyor is greater than the preset maximum length of the goods in the conveying direction. The position of the deceleration sensor and the arrangement of the first roller and the second roller are set. The automated warehouse according to claim 2.

5. The lifting and conveying device includes an incoming lifting and conveying device for carrying goods into each shelf of the rack and an outgoing lifting and conveying device for carrying goods out from each shelf of the rack. In the incoming lifting and conveying device, the upstream roller conveyor is arranged on the side far from the rack, and the downstream roller conveyor is arranged on the side close to the rack. In the outgoing lifting and conveying device, the upstream roller conveyor is arranged on the side close to the rack, and the downstream roller conveyor is arranged on the side far from the rack. In the incoming lifting and conveying device and the outgoing lifting and conveying device, in both the upstream roller conveyor and the downstream roller conveyor, the first roller is arranged on the downstream side, and the second roller is arranged on the upstream side. The automated warehouse according to claim 2 or claim 4.

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