Lifting devices and automated warehouses

Abstract

This determines the conditions under which belt malfunctions are likely to occur in lifting devices. [Solution] The lifting device comprises a column extending vertically, a drive source, a platform on which objects are placed, and a lifting mechanism for raising and lowering the platform along the column in conjunction with the drive of the drive source. The lifting mechanism comprises a pulley driven in conjunction with the drive of the drive source, a belt wrapped around the pulley and transmitting the driving force of the pulley to the platform, a biasing mechanism that biases the belt using a biasing member, and a measuring unit for measuring a physical quantity corresponding to the amount of deformation of the biasing member. It further comprises a determination unit for determining signs of abnormality in the belt based on the amount of deformation.

Description

Technical Field

[0001] The technology disclosed in this specification relates to a lifting device for lifting and lowering objects.

Background Art

[0002] In an automated warehouse, a cart travels between multiple levels of storage shelves, enabling objects to be stored in or retrieved from the storage shelves (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] An automated warehouse is equipped with a lifting device for raising and lowering a cart between multiple levels of shelves. The lifting device drives a belt wound around a pulley on a column extending in the vertical direction by a driving source to raise and lower a platform on which the cart is placed.

[0005] Although the above-mentioned belt in the lifting device has a certain tension, the tension of the belt may change over time or due to repeated driving. In that case, due to belt abnormalities, the platform being lifted and lowered is likely to sway, or the stop position may shift.

[0006] The technology disclosed in this specification has been made in view of the problems described above, and is a technology for determining a state in which belt abnormalities in a lifting device are likely to occur.

Means for Solving the Problems

[0007] A first aspect of the technology disclosed in this specification is a lifting device comprising a vertically extending column, a drive source, a platform on which objects are placed, and a lifting mechanism for raising and lowering the platform along the column in conjunction with the drive of the drive source, wherein the lifting mechanism comprises a pulley driven in conjunction with the drive of the drive source, a belt wrapped around the pulley and transmitting the driving force of the pulley to the platform, a biasing mechanism that biases the belt using a biasing member, and a measuring unit for measuring a physical quantity corresponding to the amount of deformation of the biasing member, and further comprises a determination unit for determining an abnormality in the belt based on the amount of deformation. [Effects of the Invention]

[0008] According to at least the first aspect of the technology disclosed in this specification, a condition in which a belt in a lifting device is prone to malfunction can be determined as a warning sign of malfunction.

[0009] Furthermore, the purposes, features, aspects, and advantages related to the technology disclosed in this specification will become even clearer from the detailed description and accompanying drawings provided below. [Brief explanation of the drawing]

[0010] [Figure 1] Figure 1 is a schematic side view showing an example of the configuration of an automated warehouse according to an embodiment. [Figure 2] Figure 2 is a schematic plan view showing an example of the configuration of an automated warehouse according to an embodiment. [Figure 3] Figure 3 is a perspective view showing an example of the configuration of a trolley that travels in an automated warehouse. [Figure 4] Figure 4 is a perspective view showing an example of the configuration of a lifting device. [Figure 5] Figure 5 is a partial perspective view showing an example of the configuration of a lifting device. [Figure 6] Figure 6 shows the peripheral portion of the drive pulley as viewed along the axial direction of the drive pulley. [Modes for carrying out the invention]

[0011] The embodiments will be described below with reference to the attached drawings. In the following embodiments, detailed features will be shown for the purpose of explaining the technology, but these are illustrative, and not all of them are necessarily essential features for the embodiments to be implementable.

[0012] Please note that the drawings are for illustrative purposes only, and for the sake of clarity, some components may be omitted or simplified as appropriate. Furthermore, the relative sizes and positions of components shown in different drawings are not necessarily accurately represented and may be modified as appropriate. In addition, hatching may be used in drawings other than cross-sectional views, such as plan views, to facilitate understanding of the embodiment.

[0013] Furthermore, in the following explanations, similar components will be denoted by the same symbols, and their names and functions will also be the same. Therefore, detailed explanations of them may be omitted to avoid redundancy.

[0014] Furthermore, in the descriptions contained in this specification, when a certain component is described as "equipped with," "includes," or "has," unless otherwise specified, it is not an exclusive expression that excludes the existence of other components.

[0015] Furthermore, even if ordinal numbers such as "first" or "second" are used in the descriptions contained herein, these terms are used for convenience to facilitate understanding of the embodiments, and the contents of the embodiments are not limited to the order that may result from these ordinal numbers.

[0016] Furthermore, when the description in this specification states "A or B," such statement shall include both cases where only A or B is indicated, and cases where both A and B are indicated, as long as there is no contradiction.

[0017] In addition, in the description set forth in the specification of the present application, expressions such as “… axis positive direction” or “… axis negative direction” shall take the direction along the arrow of the … axis shown in the figure as the positive direction, and the direction opposite to the arrow of the … axis shown in the figure as the negative direction.

[0018] In addition, in the description set forth in the specification of the present application, even if terms meaning specific positions or directions such as “upper”, “lower”, “left”, “right”, “side”, “bottom”, “front” or “back” are used, these terms are used for convenience in order to facilitate understanding of the content of the embodiment, and have no relation to the position or direction when the embodiment is actually implemented.

[0019] <Embodiment> Hereinafter, a lifting device and an automated warehouse according to the present embodiment will be described.

[0020] <Regarding the configuration> FIG. 1 is a side view schematically showing an example of the configuration of an automated warehouse according to the present embodiment. Further, FIG. 2 is a plan view schematically showing an example of the configuration of an automated warehouse according to the present embodiment. Further, FIG. 3 is a perspective view showing an example of the configuration of a carriage traveling in the automated warehouse.

[0021] The inbound conveyor 16 is an example of an outer conveying device that conveys the article 10 from a position outside the storage shelf 50 toward a position closer to the storage shelf 50. The outbound conveyor 18 is an example of an outer conveying device that conveys the article 10 from a position close to the storage shelf 50 toward an outer position away from the storage shelf 50. The inbound conveyor 16 and the outbound conveyor 18 are, for example, roller conveyors or belt conveyors.

[0022] The storage rack 50 is provided on at least one side of the travel path 48 of the trolley 40, which is a transporter that transports objects horizontally. In this embodiment, a pair of storage racks 50 are provided on both sides of the travel path 48. The storage rack 50 has multiple shelves 52 that are supported at intervals in the vertical direction (the Z-axis direction corresponding to the vertical direction). Each shelf 52 in each level can support and store objects 10. Each shelf 52 in each level can also support multiple objects 10. Therefore, when viewed as a whole, the storage rack 50 stores multiple objects 10 arranged vertically and horizontally. In the storage rack 50, the space in which the objects 10 are stored is the storage space. Therefore, the storage rack 50 has multiple storage spaces arranged along the direction of movement of the trolley 40 traveling on the travel path 48. Each storage space may be continuous without partitions, or it may be partitioned.

[0023] The travel path 48 is provided along the extending direction (X-axis direction) of the storage rack 50, specifically between a pair of storage racks 50, along the extending direction between them. The travel path 48 extends along the extending direction of the storage rack 50 and extends to the transfer device 60. The travel path 48 is provided corresponding to each of the multiple upper and lower levels of racks 52. Each travel path 48 may be configured, for example, with a pair of rails. The rails may also serve as the lateral frames of the storage rack 50, or they may be configured separately from the storage rack 50.

[0024] The trolley 40, also called a picker or dolly, is configured to travel back and forth along a travel path 48 extending in the X-axis direction. The trolley 40 is equipped with an object loading / unloading mechanism 42 for loading and unloading objects 10 to and from the storage rack 50 and the transfer device 60.

[0025] A lifting device 30 and a transfer device 60 are provided in a portion of the storage rack 50 in the direction of its extension. In this embodiment, a transfer device 60 for receiving goods, a lifting device 30 for receiving goods, and a conveyor 16 for receiving goods are provided at one end of each of the pair of storage racks 50. In addition, a transfer device 60 for shipping goods, a lifting device 30 for shipping goods, and a conveyor 18 for shipping goods are provided at the other end of each of the pair of storage racks 50. A transfer device, a lifting device, and a conveyor for receiving and shipping goods may also be provided in the middle of the longitudinal direction of the pair of storage racks 50. The transfer device, lifting device, and conveyor do not need to be separated into receiving and shipping types, and may be used for both receiving and shipping goods.

[0026] The transfer device 60, also known as the temporary storage shelf, is a device that relays objects between the lifting device 30 and the trolley 40. The transfer device 60 is equipped with multiple support bases 62, each corresponding to one of the multiple shelves 52. The multiple support bases 62 are located next to the storage shelf 50 and at the same height as the corresponding shelf 52. The support bases 62 are, for example, roller conveyors with rollers. By rotating a motor built into the roller, objects 10 can be moved along the transport direction. The objects 10 on the support bases 62 may also be pushed along the transport direction by a pusher driven by an actuator such as a cylinder, which is provided separately. The trolleys 40, provided corresponding to each shelf 52, can transfer objects 10 to the support bases 62 and shelves 52.

[0027] The lifting device 30 is a lifting device that directly or indirectly passes or receives objects 10 to or from a trolley 40, or to an external transport device, such as an inbound conveyor 16 or an outbound conveyor 18. In this embodiment, the inbound lifting device 30 directly receives objects 10 from the inbound conveyor 16. The lifting device 30 indirectly passes objects 10 to the trolley 40 via an inbound transfer device 60. The outbound lifting device 30 also indirectly receives objects 10 from the trolley 40 via an outbound transfer device 60. The outbound lifting device 30 directly passes objects 10 to or from the outbound conveyor 18. The lifting device 30 may also directly pass or receive objects 10 to or from the transfer device 60.

[0028] The lifting device 30 is a device that lifts and lowers the object 10, and is also called a reservoir. The lifting device 30 comprises a column portion 31 extending in the vertical direction (Z-axis direction) and a lifting platform 32 that supports the object 10 and moves up and down by the drive of a lifting drive mechanism (not shown here). The configuration of the lifting drive mechanism will be described later. As a result, the lifting platform 32 is moved up and down to a position corresponding to each of the multiple support platforms 62 at a position adjacent to the transfer device 60. When the lifting platform 32 is positioned at a height corresponding to any of the support platforms 62, the object 10 can be moved horizontally between the lifting platform 32 and the support platform 62 and transferred. In addition, the lifting platform 32 is moved up and down to a position corresponding to the receiving conveyor 16 or the shipping conveyor 18 at a position adjacent to the end of the receiving conveyor 16 or the shipping conveyor 18 that is closest to the storage rack 50. By positioning the lifting platform 32 at a height corresponding to the receiving conveyor 16 or the shipping conveyor 18, the object 10 can be moved horizontally between the lifting platform 32 and the receiving conveyor 16 or the shipping conveyor 18.

[0029] The control unit 100 controls the transport operations of the receiving conveyor 16 and the outgoing conveyor 18, the lifting and lowering operations of the lifting device 30, the transfer operations, the transfer operations of the transfer device 60, the travel operations of the trolley 40, and the loading and unloading operations of the goods 10. In the automated warehouse 20, the goods 10 are loaded and unloaded under the control of the control unit 100.

[0030] The control unit 100 may include, for example, a storage device including a memory (recording medium) such as a hard disk drive (i.e., HDD), random access memory (i.e., RAM), read-only memory (i.e., ROM), flash memory, volatile or non-volatile semiconductor memory, magnetic disk, flexible disk, optical disk, compact disk, minidisc, or DVD; a processing circuit such as a central processing unit (i.e., CPU) that executes programs stored in the storage device, an external CD-ROM, an external DVD-ROM, or an external flash memory; an input device that can input information such as a mouse, keyboard, touch panel, or various switches; and an output device that can output information such as a display, liquid crystal display, or lamp.

[0031] In the automated warehouse 20, when an item 10 is received, a database is generated and updated that associates the item 10's identification information (item identification code or name) with its storage location. When an item 10 is received, the available space on the storage shelf 50 is identified by referring to this database, and one of these available spaces is selected as the planned storage location. When an item 10 is released, its storage location is identified by referring to the database. The database may be stored in the storage unit of the control unit 100, or it may be stored in another storage unit.

[0032] As shown in Figure 3, the trolley 40 comprises a body 41 and an item loading / unloading mechanism 42. The trolley 40 is an example of a device for loading or unloading items 10 to or from the storage rack 50.

[0033] The vehicle body 41 is configured to move the loading / unloading mechanism 42 between positions corresponding to the shelves 52 or support bases 62. The vehicle body 41 also incorporates a drive unit 141, which includes a motor and gears. Driven by the drive unit 141, wheels 41a and 41b of the wheels 41a, 41b, 41c, and 41d attached to the vehicle body 41 rotate, allowing the vehicle body 41 to travel along the travel path 48. At each level, as the vehicle body 41 moves back and forth along the travel path 48, the loading / unloading mechanism 42 moves to a position opposite one of the shelves 52 at that level (specifically, a position opposite the position on the shelf 52 where an object 10 is placed or an empty space where an object 10 should be placed), or to a position opposite the support base 62.

[0034] The trolley 40 is equipped with a transfer control unit 341, and the control unit 100 provides the transfer control unit 341 with a control signal to control the operation of the trolley 40. Based on this control signal, the transfer control unit 341 controls the operation of the travel drive unit 141, the arm drive unit 241, etc. In addition, data indicating the state of the trolley 40 acquired by the trolley 40 is output to the outside through the transfer control unit 341.

[0035] The object loading / unloading mechanism 42 is a device that takes in an object 10 from the outside into itself, or sends an object 10 from the inside into itself out. The object loading / unloading mechanism 42 comprises a loading platform 45 on which the object 10 is placed, a pair of arms 43 that can move in and out in the Y-axis direction relative to the storage shelf 50 and the transfer device 60, and a pair of claws 44 provided on the leading end of the pair of arms 43 in the direction of extension and in front of the leading end. The upper surface of the loading platform 45 is formed as a plane that is the same as or larger than the bottom surface of the object 10, and spreads along the horizontal direction.

[0036] The pair of arms 43 are driven forward and backward by an arm drive unit 241, which includes a motor. The claws 44 can change their orientation between a state where they are tilted so as to protrude from the ends of the arms 43 by the drive of the motor, etc., and a state where they are aligned vertically along the ends of the arms 43.

[0037] The pair of claws 44 at the leading edge of the pair of arms 43 and the pair of claws 44 closer to the front of the leading edge can be reversed if the direction of extension of the pair of arms 43 is reversed. With the pair of claws closer to the front of the leading edge protruding, the pair of arms 43 are extended, pushing the object 10 on the mounting platform 45 towards the storage shelf 50 or transfer device 60. With the pair of arms 43 extended, the pair of claws 44 at the leading edge are protruding, and then the pair of arms 43 are retracted. This pulls the object 10 on the storage shelf 50 or transfer device 60 side onto the mounting platform 45. As a result, the object 10 is moved between the trolley 40 and the storage shelf 50 or transfer device 60. The object 10 is loaded and unloaded from the storage shelf 50 from the travel path 48 side. The trolley 40 traveling on the travel path 48 can load and unload the object 10 to both of the pair of storage shelves 50.

[0038] <About the lifting device> The lifting device 30 will be described in detail below. Figure 4 is a perspective view showing an example of the configuration of the lifting device 30.

[0039] As shown in Figure 4, the lifting device 30 comprises a lifting platform 32, a column 31, and a lifting drive mechanism 70.

[0040] The column section 31 is installed on the installation surface of the automated warehouse 20 in a vertical orientation aligned with the direction of gravity.

[0041] The lifting platform 32 is supported so as to be able to move up and down by the column portion 31. More specifically, the movable lifting support portion 32L is supported so as to be able to move up and down relative to the column portion 31. For example, the movable lifting support portion 32L has a guide groove that fits into an elongated plate-shaped rail formed on the column portion 31, and the guide groove is guided by the rail so as to be supported so as to be able to move up and down relative to the column portion 31. Rolling elements such as wheels may be interposed between the movable lifting support portion 32L and the column portion 31.

[0042] A lifting support frame 32LF extends horizontally outward from the movable lifting support section 32L. The lifting support frame 32LF extends toward the bottom of the lifting mounting platform 32, and the bottom of the lifting mounting platform 32 is fixed to the lifting support frame 32LF by screws or the like. The lifting motion of the lifting drive mechanism 70 is transmitted to the lifting mounting platform 32 via the movable lifting support section 32L. As a result, the lifting mounting platform 32 moves up and down along the column section 31.

[0043] The lifting drive mechanism 70 comprises a drive source 72 and a lifting mechanism 74.

[0044] The drive source 72 is electrically controlled by the control unit 100 to generate power to move the lifting platform 32 up and down. The drive source 72 is, for example, an electric motor. The drive source 72 is positioned, for example, towards the bottom in the vertical direction of the column section 31.

[0045] The lifting mechanism 74 is configured to raise and lower the lifting platform 32 along the column 31 in conjunction with the drive of the drive source 72. The lifting mechanism 74 includes a drive pulley 76 that is driven in conjunction with the drive of the drive source 72, a driven pulley 94U, a driven pulley 94L, and a belt 90.

[0046] The belt 90 is wrapped around the drive pulley 76 and the driven pulleys 94U and 94L, and transmits the driving force of the drive pulley 76 to the lifting and lowering operation of the lifting platform 32. The driven pulley 94U is located at the upper end of the column 31, and the driven pulley 94L is located at the lower end of the column 31. The drive pulley 76 is located in the middle of the column 31 in the longitudinal direction. Guided by the drive pulley 76 and the driven pulleys 94U and 94L, the belt 90 is guided to travel in a circular path along an annular travel path that includes a vertical straight path along the column.

[0047] In this embodiment, the annular travel path of the belt 90 includes a vertical straight path on the base side that extends vertically along the main surface of the column 31 on the side of the lifting platform 32, a vertical straight path on the back side that extends vertically along the main surface of the column 31 on the side opposite to the lifting platform 32, an upper U-turn path that is folded back towards the space between the two main surfaces of the column 31 by a driven pulley 94U at the upper end of the column 31, and a lower U-turn path that is folded back towards the space between the two main surfaces of the column 31 by a driven pulley 94L at the lower end of the column 31. A movable lifting support section 32L is connected to the portion of the belt 90 that travels along the vertical straight path on the base side.

[0048] When the drive pulley 76 is rotated by the drive source 72, the rotation of the drive pulley 76 is transmitted to the belt 90, causing the belt 90 to rotate along the annular travel path. The movable lifting support 32L is connected to the vertically linear portion of the belt 90. Therefore, when the belt 90 rotates along the annular travel path, the lifting platform 32 supported by the movable lifting support 32L is driven to move up and down along the vertically linear path. As a result, the driving force of the drive source 72 is transmitted to the lifting platform 32 via the belt 90, causing the lifting platform 32 to move up and down. The belt 90 may be an annular strip-shaped member, or it may be a non-annular strip-shaped belt with both ends connected to the movable lifting support 32L to form a strip shape.

[0049] The drive pulley 76 is located in the middle of the annular travel path of the belt 90. In this embodiment, it is located in the middle of the vertical straight path on the back side of the annular travel path of the belt 90, more specifically, towards the lower part of the vertical straight path on the back side. The drive pulley 76 may also be set in an upper position, or it may be installed on the vertical straight path side of the base. The drive pulley 76 may be installed at the upper or lower end of the column portion 31 in place of the driven pulleys 94U and 94L.

[0050] The rotational driving force of the drive source 72 is transmitted to the drive pulley 76. For example, the rotating shaft of the drive source 72 is directly connected to the rotating shaft of the drive pulley 76. A transmission mechanism including at least one of a gear, pulley, or chain may be interposed between the rotating shaft of the drive source 72 and the rotating shaft of the drive pulley 76.

[0051] In the middle of the vertical straight path on the table side, the belt 90 is partially wrapped around the entire circumference of the drive pulley 76. When the rotational driving force of the drive source 72 is transmitted to the drive pulley 76, the portion of the belt 90 that is wrapped around the drive pulley 76 is moved upward or downward. As a result, the belt 90 travels in a circular motion along the annular travel path in accordance with the rotation of the drive pulley 76. As the belt 90 travels in a circular motion, the lifting platform 32 connected to the belt 90 can move up and down along the vertical straight path on the table side. By controlling the rotation direction and rotation speed of the drive source 72, the circumferential direction and circumferential speed of the belt 90 are also controlled, and in turn, the lifting direction and lifting speed of the lifting platform 32 are also controlled.

[0052] <About the drive mechanism> The part that drives the belt 90 will be explained in detail. Figure 5 is a partial perspective view showing an example of the configuration of the lifting device 30. In Figure 5, the mechanism part of the lifting device 30 that mainly drives the belt 90 is shown. Figure 6 is a view of the area around the drive pulley 76, along the axial direction of the drive pulley 76.

[0053] As shown in Figures 5 and 6, a support bracket 78 is fixed by screws or the like to the main surface of the column portion 31 in the middle of its extending direction, on the side opposite to the lifting and lowering platform 32. The support bracket 78 has a pair of side plates 79 that are spaced apart and facing each other. A drive pulley 76 is rotatably supported between the pair of side plates 79. In the portion where the drive pulley 76 is installed, the belt 90 bends to bypass the vertical straight path on the back side away from the column portion 31 and is partially wrapped around the outer circumference of the pulley body 77.

[0054] Specifically, the drive pulley 76 includes a pulley body 77 and a pair of flanges 77F.

[0055] The pulley body 77 is formed in a cylindrical or cylindrical shape. The pulley body 77 has a width greater than or equal to the width of the belt 90. Therefore, the belt 90 can be wrapped around the pulley body 77.

[0056] The pulley body 77 has an outer circumferential surface 77a that has the same outer circumferential surface shape continuously along its axial direction. That is, the cross-section is a cross-section perpendicular to the axial direction of the pulley body 77. The outer circumferential surface 77a of the pulley body 77 that appears in the cross-section has the same shape at any position along the axial direction of the pulley body 77.

[0057] The outer circumferential surface 77a may have, for example, a circular shape that is continuous along the axial direction of the pulley body 77. Alternatively, the inward-facing surface of the belt 90 may have multiple grooves for preventing slippage. Each of the multiple grooves is an elongated groove extending along the width direction of the belt 90, and the multiple grooves are formed to be aligned along the longitudinal direction of the belt 90. In this case, the pulley body 77 may have teeth that fit into the grooves of the belt 90. In this case, the outer circumferential surface 77a may have a gear shape that is continuous along the axial direction of the pulley body 77.

[0058] The axial outer edge of the outer surface of the drive pulley 76 around which the belt 90 is wound is preferably located at a distance of at least 1 / 4 of the width of the belt 90 with respect to the design travel path of the belt 90. The design travel path of the belt 90 refers to the ideal travel path that the belt 90 is restricted to by the driven pulleys 94U and 94L. In this embodiment, the axial outer edge of the outer surface of the drive pulley 76 around which the belt 90 is wound is the boundary between the outer surface 77a and the flange portion 77F. The axial outer edge of the outer surface of the drive pulley 76 around which the belt 90 is wound may be located close to the design travel path of the belt 90.

[0059] If the axial outer edge of the outer peripheral surface 77a of the drive pulley 76 is at a distance of 1 / 4 or more of the width of the belt 90 relative to the designed travel path of the belt 90, the belt 90 is less likely to come off the outer peripheral surface 77a.

[0060] The flange portion 77F is an annular portion that protrudes circumferentially outward from both ends of the pulley body 77. The flange portion 77F prevents the belt 90 from falling off the drive pulley 76 even if it deviates more than expected and moves to the outside of the outer circumferential surface 77a. Note that the flange portion 77F may be omitted.

[0061] The lifting device 30 includes a pressing roller 80 positioned around the drive pulley 76. The pressing roller 80 presses each of the belts 90, which are wrapped around the drive pulley 76, toward the drive pulley 76.

[0062] In this embodiment, the drive pulley 76 is equipped with two press rollers 80. Each of the two press rollers 80 is rotatably supported at a position away from the column portion 31, facing the outer circumferential surface 77a of the press roller 80. The two press rollers 80 are positioned apart from each other along the circumferential direction of the outer circumferential surface 77a. A gap is provided between the outer circumferential surface 77a and each of the two press rollers 80 through which the belt 90 can pass. The portion of the belt 90 wrapped around the outer circumferential surface 77a of the drive pulley 76 is sandwiched between the outer circumferential surface 77a and the press rollers 80. This presses the belt 90 toward the outer circumferential surface 77a of the drive pulley 76, making it difficult for slippage to occur between the outer circumferential surface 77a and the belt 90. For example, if the outer circumferential surface 77a has teeth that fit onto the belt 90, it becomes difficult for the teeth of the outer circumferential surface 77a to come out of a groove in the belt 90 and get stuck in another groove, so-called tooth skipping. This allows the rotation of the drive pulley 76 to be efficiently transmitted to the belt 90.

[0063] The number of pressure rollers 80 is not limited to the number mentioned above; for example, there may be one or two. The pressure rollers 80 may also be omitted.

[0064] Furthermore, the lifting device 30 includes a guide roller 82 and a guide roller 84 that change the guide path of the belt 90.

[0065] The guide roller 82 is located above the drive pulley 76 (in the positive Z-axis direction) and closer to the column 31. The guide roller 82 is rotatably supported by a pair of side plates 79. The guide roller 82 is in contact with the belt 90 on the side opposite to the side that contacts the drive pulley 76 (the outer peripheral surface). The guide roller 82 guides the portion of the belt 90 that extends upward from the drive pulley 76 to a position closer to the column 31. As a result, the portion of the belt 90 that travels above the drive pulley 76 is guided to follow a path along the column 31 near it.

[0066] The guide roller 84 is rotatably supported at a position below the drive pulley 76 (negative Z-axis direction) and closer to the column 31. The guide roller 84 is in contact with the belt 90 on the side opposite to the side that contacts the drive pulley 76 (the outer peripheral surface). The guide roller 84 guides the portion of the belt 90 that extends downward from the drive pulley 76 to a position closer to the column 31. As a result, the portion of the belt 90 that travels below the drive pulley 76 is guided to follow a path along the column 31 near it.

[0067] In this embodiment, the guide roller 84 is supported so as to be movable along the pushing direction that pushes the belt 90 between the column portion 31 and the drive pulley 76, and is biased in the direction that pushes the belt 90 (pushing direction).

[0068] More specifically, a movable support portion 85 is movably supported inside a pair of side plates 79. The movable support portion 85 includes a pair of movable side plates 85a and a connecting portion 85b that connects the outer ends of the pair of movable side plates 85a. For example, the movable support portion 85 is supported so as to be movable along the pushing direction by the pair of movable side plates 85a being guided into grooves inside the pair of side plates 79. In addition, the guide roller 84 is rotatably supported between the pair of movable side plates 85a, so the guide roller 84 is also supported so as to be movable along the pushing direction.

[0069] The biasing mechanism biases the movable support 85 and the guide roller 84 in the pushing direction (biasing direction) using a biasing member. The biasing mechanism includes a fixed plate 87 that uses a spring 88, which is expandable and contractible in the biasing direction, as a biasing member. The fixed plate 87 is fixed at a fixed position away from the movable support 85 by a pair of side plates 79 or a support rod 87p extending from the column 31. The spring 88 is positioned in a compressed state between the fixed plate 87 and the movable support 85. Due to the elastic force of the spring 88, the movable support 85 and the guide roller 84 are biased toward the space between the column 31 and the drive pulley 76 along the pushing direction. As a result, the portion of the belt 90 that runs below the drive pulley 76 is guided by the guide roller 84 while being biased toward the space between the column 31 and the drive pulley 76. This applies tension to the belt 90, making it difficult for slippage to occur between the outer circumferential surface 77a of the drive pulley 76 and the belt 90.

[0070] The biasing member for biasing the guide roller 84 is not limited to the spring 88 described above, but may also be, for example, one that uses the elastic restoring force of rubber in a torsional state.

[0071] Furthermore, the lifting device 30 is equipped with a distance sensor 36. The distance sensor 36 is, for example, an optical sensor that measures the distance to an object by irradiating it with laser light. In Figures 4, 5, and 6, the distance sensor 36 is fixed to an external location spaced apart from the biasing mechanism, the movable support part 85, and the guide roller 84, using legs or the like (not shown). However, the location where the distance sensor 36 is provided is not limited to this case. The distance sensor 36 may be attached to, for example, the fixing plate 87 or to the movable support part 85.

[0072] The distance sensor 36 measures the distance from one end of the spring 88 to the opposite end of the spring 88. For example, it measures the distance from the fixed plate 87 side of the spring 88 to the movable support part 85 located on the opposite side. Also, for example, when the spring 88 is attached to the movable support part 85, it measures the distance to the fixed plate 87 located on the opposite side. The direction of the laser beam emitted from the distance sensor 36 is preferably along the extension and contraction direction of the spring 88, but it may also be inclined with respect to the extension and contraction direction of the spring 88.

[0073] In this embodiment, a distance sensor 36 was used to measure the amount of expansion and contraction (deformation) of the spring 88. However, any measuring instrument capable of measuring the deformation of a biasing member including the spring 88 may be used. For example, the amount of expansion and contraction (deformation) of the spring 88 may be measured using a strain sensor attached to the spring 88.

[0074] <About operation> Next, the operation of the lifting device 30 in the automated warehouse will be described.

[0075] The lifting device 30 rotates the drive source 72 in response to a control signal from the control unit 100, thereby driving the lifting platform 32 up and down.

[0076] The belt 90 is supported by being wound around the driven pulleys 94U, 94L, and drive pulley 76, so that it can travel along an annular travel path including the vertical straight path on the base side, the vertical straight path on the back side, the upper U-turn path, and the lower U-turn path. In this state, the belt 90 is pressed against the drive pulley 76 by the pressing roller 80. In addition, tension is applied to the belt 90 by the biasing force of the guide roller 84. The belt 90 is wound around the driven pulleys 94U, 94L, and drive pulley 76 in a configuration that allows the same mechanical force to act on them.

[0077] When the drive source 72 is rotationally driven, the drive pulley 76 rotates. The portion of the belt 90 that was wrapped around the drive pulley 76 is fed upward or downward. As a result, the belt 90 travels along the annular travel path guided by the driven pulleys 94U and 94L. The lifting platform 32 is connected to the belt 90 and therefore rises or falls according to the direction of travel of the belt 90.

[0078] The belt 90 may stretch longitudinally due to the passage of time or repeated driving. In the lifting device 30, the belt 90 is biased by a biasing mechanism, so the tension of the belt 90 is kept constant. However, as the belt 90 stretches, the shape of the biasing member changes, and the biasing force may change accordingly. For example, if the spring 88 that biases the belt 90 stretches beyond a predetermined limit, the biasing force may not be kept constant and may decrease. In this case, the tension of the biased belt 90 changes (for example, decreases), and when the lifting platform 32 is driven up and down, the lifting platform 32 may become more prone to shaking, or the stopping position of the lifting platform 32 may shift.

[0079] Therefore, in this embodiment, the elongation of the belt 90 is monitored by measuring the amount of expansion and contraction (deformation) of the biasing member biasing the belt 90 using a distance sensor 36, and the lifting and lowering platform 32 is driven up and down while appropriately maintaining the tension of the belt 90.

[0080] Specifically, the distance from the distance sensor 36 to the movable support part 85 is measured using the distance sensor 36. The movable support part 85 moves toward the belt 90 along with the end of the spring 88 when the spring 88 biases the belt 90, so the distance to the movable support part 85 changes according to the length (amount of expansion / contraction) of the spring 88 between the fixed plate 87 and the movable support part 85. In other words, the distance from the distance sensor 36 to the movable support part 85 is a physical quantity corresponding to the amount of deformation (amount of expansion / contraction) of the spring 88. When the belt 90 stretches, the length of the spring 88 biasing the belt 90 stretches accordingly, so by measuring the distance to the movable support part 85 using the distance sensor 36, the amount of deformation of the spring 88 can be determined, and furthermore, the change in the length of the belt 90 can be monitored based on this amount of deformation.

[0081] The control unit 100 monitors the distance to the movable support part 85, which is measured by the distance sensor 36. The control unit 100 determines that if the distance measured by the distance sensor 36 is greater than or equal to a predetermined threshold, that is, if the deformation amount of the spring 88 is greater than or equal to a predetermined threshold, it is a sign of an impending abnormality, indicating that the belt 90 is prone to malfunction. It should be noted that the determination of an impending abnormality includes cases where the tension of the belt 90 is currently maintained at a constant level. In other words, according to this embodiment, even if the guide roller 84 is pushed in by the biasing mechanism and the belt 90 still has appropriate tension, it can be determined as an impending abnormality, indicating that the belt 90 is prone to malfunction. Furthermore, the threshold can be set to any value depending on the drive accuracy required of the lifting device 30, and different values ​​can also be set depending on the drive state of the lifting device 30 (stopped, raised, and lowered).

[0082] The control unit 100 monitors the analog signal output from the distance sensor 36, which indicates the distance to the movable support part 85, in real time. If the signal exceeds the threshold value, it can issue a warning, for example, an anomaly warning via a display or the like. This warning allows for the detection of loosening of the belt 90's tension before an actual anomaly occurs, thus providing sufficient time for maintenance and enabling efficient maintenance.

[0083] The threshold value mentioned above may be a value generated by machine learning using the distance to the movable support part 85 that has been measured multiple times in the past by the distance sensor 36 as input. The machine learning may be performed based on multiple data showing the distance to the movable support part 85 when the tension of the belt 90 is within the normal range, and multiple data showing the distance to the movable support part 85 when the tension of the belt 90 is outside the normal range (for example, when the tension is low), each as training data. Alternatively, machine learning (unsupervised learning) may be performed only from multiple data showing the distance to the movable support part 85 when the tension of the belt 90 is within the normal range.

[0084] Any type of classifier may be used in the above machine learning, for example, it may be an SVM (Support Vector Machine) or a neural network.

[0085] <Modifications of the embodiments described above> In the embodiments described above, the material, dimensions, shape, relative arrangement, or implementation conditions of each component may also be described, but these are all examples and not limiting.

[0086] Therefore, countless variations and equivalents not shown are envisioned within the scope of the art disclosed in this specification. For example, these include modifications, additions, or omissions of at least one component.

[0087] <Note> This disclosure discloses the following aspects:

[0088] A lifting device according to the first embodiment comprises a column extending in the vertical direction, a drive source, a platform on which objects are placed, and a lifting mechanism for raising and lowering the platform along the column in conjunction with the drive of the drive source, wherein the lifting mechanism comprises a pulley driven in conjunction with the drive of the drive source, a belt wrapped around the pulley and transmitting the driving force of the pulley to the platform, a biasing mechanism that biases the belt using a biasing member, and a measuring unit for measuring a physical quantity corresponding to the amount of deformation of the biasing member, and further comprises a determination unit for determining signs of abnormality in the belt based on the amount of deformation.

[0089] According to the first embodiment, conditions in the lifting device that are prone to belt abnormalities can be detected in advance when the belt elongation prevents the biasing mechanism from obtaining the appropriate biasing force due to belt elongation, thereby determining signs of abnormality and enabling appropriate maintenance.

[0090] The configurations relating to the second and subsequent embodiments may be adopted as optional configurations that are not mandatory.

[0091] The second embodiment of the lifting device is the same as the lifting device of the first embodiment, wherein the pulley includes a drive pulley that is driven in conjunction with the drive of the drive source and at least one driven pulley, and the belt is wrapped around the drive pulley and the driven pulley, and transmits the driving force of the drive pulley to the mounting base.

[0092] According to the second embodiment, the amount of belt elongation can be calculated from the amount of deformation of the biasing member to determine an abnormality.

[0093] The third embodiment of the lifting device is a lifting device according to the first or second embodiment, wherein the biasing member is a spring that can expand and contract in the biasing direction, and the measuring unit measures the physical quantity corresponding to the amount of expansion and contraction of the spring in the biasing direction.

[0094] According to the third embodiment, the amount of belt elongation can be calculated from the amount of spring expansion and contraction to determine an abnormality.

[0095] The fourth embodiment of the lifting device is the lifting device according to the third embodiment, wherein the measuring unit is an optical sensor capable of measuring the length of the spring in the biasing direction.

[0096] According to the fourth embodiment, the length of the spring can be measured with an optical sensor to determine signs of abnormality.

[0097] The fifth embodiment of the lifting device is a lifting device according to any one of the first to fourth embodiments, in which the determination unit determines that the deformation amount is greater than or equal to a predetermined threshold value, and determines that this is a sign of abnormality in the belt.

[0098] According to the fifth embodiment, it is possible to determine that an abnormality is a sign when the amount of deformation of the biasing member is greater than or equal to a threshold.

[0099] The sixth embodiment of the lifting device is a lifting device according to the fifth embodiment, wherein the threshold includes a first threshold and a second threshold that is a different value from the first threshold, and the determination unit determines that the belt is showing signs of abnormality if the deformation amount is greater than or equal to the first threshold while the platform is moving up or down, and the determination unit determines that the belt is showing signs of abnormality if the deformation amount is greater than or equal to the second threshold while the platform is stopped.

[0100] According to the sixth embodiment, abnormal signs can be determined based on different thresholds depending on the state of the placement stand.

[0101] The seventh embodiment of the lifting device is a lifting device according to the fifth or sixth embodiment in which the threshold value is a value generated by machine learning using data of the physical quantities corresponding to a plurality of deformation amounts already measured in the measurement unit as input.

[0102] According to the seventh aspect, a threshold can be determined by machine learning to detect anomaly signs.

[0103] The automated warehouse according to the eighth embodiment comprises a plurality of storage shelves for storing the items, a lifting device according to any one of the first to seventh embodiments for raising and lowering the placement platform to each of the storage shelves, and a transporter for transporting the items between the storage shelves and the placement platform.

[0104] According to the eighth aspect, maintenance can be performed appropriately by determining an abnormality by calculating the amount of belt elongation from the amount of deformation of the biasing member. [Explanation of Symbols]

[0105] 10 things 20 Automated Warehouse 30 Lifting device 31 Column section 52 shelves 72 Power source 74 Lifting mechanism 76 Drive pulley 82 Guide roller 84 Guide roller 90 belt 94L Driven Pulley 94U Driven Pulley

Claims

1. A column extending in the vertical direction, Power source and A display stand on which objects are placed, The system includes a lifting mechanism for raising and lowering the mounting platform along the column in conjunction with the drive of the drive source, The aforementioned lifting mechanism A pulley that is driven in conjunction with the drive source, A belt that is wrapped around the pulley and transmits the driving force of the pulley to the mounting base, A biasing mechanism that biases the belt using a biasing member, The system includes a measuring unit for measuring a physical quantity corresponding to the amount of deformation of the biasing member, The system further includes a determination unit for determining an abnormality in the belt based on the amount of deformation. Lifting device.

2. The lifting device according to claim 1, The aforementioned pulley, A drive pulley that is driven in conjunction with the drive of the aforementioned drive source, Includes at least one driven pulley, The belt is wrapped around the drive pulley and the driven pulley, and transmits the driving force of the drive pulley to the mounting base. Lifting device.

3. A lifting device according to claim 1 or 2, The biasing member is a spring that can expand and contract in the biasing direction. The measuring unit measures the physical quantity corresponding to the amount of expansion and contraction of the spring in the biasing direction. Lifting device.

4. The lifting device according to claim 3, The measurement unit is an optical sensor capable of measuring the length of the spring in the biasing direction. Lifting device.

5. A lifting device according to claim 1 or 2, The determination unit determines that the deformation amount is above a predetermined threshold value, and that this is a sign of an abnormality in the belt. Lifting device.

6. The lifting device according to claim 5, The threshold includes a first threshold and a second threshold that has a different value from the first threshold. While the platform is moving up and down, the determination unit determines that the deformation amount is greater than or equal to the first threshold value, and that this is a sign of an abnormality in the belt. While the mounting platform is stopped, the determination unit determines that the deformation amount is greater than or equal to the second threshold value, which indicates a potential abnormality in the belt. Lifting device.

7. The lifting device according to claim 5, The threshold value is a value generated by machine learning using data of the physical quantities corresponding to a plurality of deformation amounts already measured in the measurement unit as input. Lifting device.

8. A multi-tiered storage shelf for storing the aforementioned items, A lifting device according to claim 1 or 2 for raising and lowering the placement platform to each level of the storage shelf, A transporter for transporting the object is provided between the storage shelf and the placement stand. Automated warehouse.

Images