Conveying device
The conveying device employs a light-based detection system to identify abnormalities in suspension members by displacing a light-shielding section onto the optical path when tensile force deviates, addressing the cost issue of multiple detection devices in conventional systems.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- MURATA MASCH LTD
- Filing Date
- 2023-12-11
- Publication Date
- 2026-05-26
AI Technical Summary
Conventional conveying devices that suspend and support a lifting part using multiple suspension members require costly devices for detecting abnormalities in each suspension member.
A conveying device with a lifting section and detection device that uses a light-emitting and light-receiving system to detect abnormalities in suspension mechanisms, where a light-shielding section is displaced onto the optical path when the tensile force of the suspension member changes outside the normal range, allowing a single detection device to identify issues.
This configuration reduces the need for multiple detection devices, enabling low-cost detection of abnormalities in suspension members by utilizing a single detection device.
Smart Images
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Abstract
Description
Technical Field
[0001] The present invention relates to a conveying device.
Background Art
[0002] Patent Document 1 discloses a stacker crane including a lifting part that supports a conveyance target, a pair of suspension members (for example, chains) that suspend and support the lifting part, a dog connected to each suspension member, and a pair of limit switches. In this stacker crane, when an abnormality occurs in the suspension member (for example, cutting or abnormal elongation of the suspension member), the dog is displaced and the limit switch operates. Thereby, the abnormality of the suspension member is detected.
Prior Art Documents
Patent Documents
[0003]
Patent Document 1
Summary of the Invention
Problems to be Solved by the Invention
[0004] In the above stacker crane, since it is necessary to provide a device for detecting an abnormality of the suspension member for each suspension member, the cost is high. Note that such a problem is not limited to the stacker crane and is common in a conveying device that suspends and supports a lifting part by a plurality of suspension members.
[0005] An object of the present invention is to provide a conveying device capable of detecting an abnormality of a suspension member at a low cost.
Means for Solving the Problems
[0006] A transport device according to an aspect of the present invention comprises a lifting section for supporting an article, and a lifting device for raising and lowering the lifting section in the vertical direction. The lifting device comprises a plurality of suspension mechanisms that support the lifting section so that it can move up and down in the vertical direction, and a detection device for detecting abnormalities in the suspension mechanisms. The detection device comprises a light-emitting section that emits inspection light and a light-receiving section that receives the inspection light. Each suspension mechanism comprises a suspension member that suspends the lifting section, an elastic member that expands and contracts in accordance with the tensile force of the suspension member, and a light-shielding section that is displaced vertically in accordance with the expansion and contraction of the elastic member. Each light-shielding section is outside the optical path of the inspection light when the tensile force is within the normal range, and is displaced onto the optical path of the inspection light when the tensile force changes from within the normal range to outside the normal range. A transport device according to an aspect of the present invention comprises a lifting section for supporting an article, and a lifting device for raising and lowering the lifting section in the vertical direction. The lifting device comprises a plurality of suspension mechanisms that support the lifting section so that it can move up and down in the vertical direction, and a detection device for detecting abnormalities in the suspension mechanisms. The detection device comprises a light-emitting section that emits inspection light and a light-receiving section that receives the inspection light. Each suspension mechanism comprises a suspension member that suspends the lifting section, an elastic member that expands and contracts in accordance with the tensile force of the suspension member, and a light-shielding section that is displaced vertically in accordance with the expansion and contraction of the elastic member. Each light-shielding section is such that the tensile force is within the normal range. When it is in the wrong position, it is out of the optical path of the inspection light, and when the tensile force changes from within the normal range to outside the normal range, it is displaced onto the optical path of the inspection light. Each suspension mechanism is equipped with a sliding part that can slide vertically relative to the lifting part, and one end of the suspension member is connected to the sliding part. An elastic member is provided between a part of the lifting part and a part of the sliding part, and it contracts or expands according to the relative positional relationship between the sliding part and the lifting part in the vertical direction, and the positional relationship changes as the sliding part and the lifting part slide relative to each other due to fluctuations in the tensile force. [Effects of the Invention]
[0007] In the conveying device according to an aspect of the present invention, if an abnormality occurs, such as a phase shift between multiple suspension members or damage to at least one suspension member, the tensile force of at least one suspension member may change outside the normal range. As a result, the inspection light is blocked by the displaced light-shielding portion, and the conveying device detects the abnormality with a single detection device. This eliminates the need to provide multiple detection devices for detecting abnormalities, thus enabling low-cost detection of abnormalities.
[0008] Furthermore, in the conveying device according to the above embodiment, a lifting mechanism may be connected to one end of each of the multiple suspension members, and an adjustment mechanism for adjusting the weight balance may be connected to the other end of each of the multiple suspension members. With such a configuration, abnormalities can be detected more appropriately in the end suspension members, which are prone to phase shifts.
[0009] Furthermore, in the conveying device according to the above embodiment, each suspension mechanism is equipped with a sliding part that can slide vertically relative to the lifting part, one end of the suspension member is connected to the sliding part, and the elastic member is provided between a part of the lifting part and a part of the sliding part, and contracts or expands according to the relative positional relationship between the sliding part and the lifting part in the vertical direction, and the positional relationship may change as the sliding part and the lifting part slide relative to each other due to fluctuations in tensile force. With such a configuration, the number of parts required to detect abnormalities can be reduced compared to conventional devices.
[0010] Furthermore, in the conveying device according to the above embodiment, the lifting section comprises a mounting section on which an article is placed, a first member extending upward from the end of the mounting section, and a second member extending horizontally from the upper part of the first member; the sliding section comprises a shaft inserted into a through hole formed in the second member and extending vertically, a gripping section provided at the upper end of the shaft for gripping the end of the suspension member, and a receiving section provided at the lower end of the shaft; and the elastic member may be provided between the lower surface of the second member and the receiving section.
[0011] Furthermore, in the conveying device according to the above embodiment, when the tensile force is within the normal range, the elastic member may contract beyond its natural length and the light-shielding portion may be located above the optical path of the inspection light. When the tensile force changes from within the normal range to outside the normal range, the elastic member may stretch and the light-shielding portion may be displaced downward toward the optical path of the inspection light. In addition, in the conveying device according to the above embodiment, the detection device may be provided at the upper end of the first member, and the light-shielding portion may be provided at each of the multiple gripping portions. [Brief explanation of the drawing]
[0012] [Figure 1] This is a schematic diagram of the storage device according to this embodiment. [Figure 2] This is a perspective view of the upper part of the lifting platform and a part of the lifting device according to this embodiment. [Figure 3] This is a front view of the suspension mechanism according to this embodiment. [Figure 4] This is a side view of the suspension mechanism according to this embodiment. [Figure 5] This is a plan view of the detection device according to this embodiment. [Figure 6] This figure shows the operation of the suspension mechanism in an abnormal state according to this embodiment. [Modes for carrying out the invention]
[0013] The present invention will be described below through embodiments, but the following embodiments are not limited to the invention as defined in the claims. Furthermore, not all combinations of features described in the embodiments are necessarily essential to the solution of the invention. In addition, in the drawings, the same or similar parts are denoted by the same reference numerals, and redundant explanations may be omitted. Also, the shape and size of elements in the drawings may be exaggerated for clearer explanation, and may differ in shape and dimensions from the actual product.
[0014] In some diagrams, directions are explained using the XYZ coordinate system. In the XYZ coordinate system, the plane parallel to the horizontal plane is defined as the XY plane. One direction in this XY plane is denoted as the X direction, and the direction perpendicular to the X direction is denoted as the Y direction. The direction perpendicular to the XY plane is denoted as the Z direction. In this embodiment, the Z direction in the diagram is the vertical direction.
[0015] The storage device 1 transfers items F between the stacker crane 30 and the shelves 10 that store multiple items F. Items F include, for example, semiconductor wafers or reticles used in the manufacture of semiconductor devices. Items F are, for example, FOUPs (Front Opening Unified Pods), SMIF Pods, or reticle Pods whose interiors can be purged.
[0016] The shelves 10 are installed, for example, on the floor of a cleanroom. The shelves 10 are arranged in a line on one or both sides in the direction of travel of the stacker crane 30 (hereinafter simply referred to as the "direction of travel"). The direction of travel is the X direction in the figure.
[0017] The storage device 1 temporarily stores an article F such as a FOUP on the shelf 10, and in response to a request from the processing device, it loads the article F onto the shelf 10 or unloads it from the article F stored on the shelf 10. Note that a stacker crane 30 is used for transporting the article F. That is, the stacker crane 30 travels along the traveling rails (lower rail 20 and upper rail 21) inside the storage device 1 while loading the article F onto the shelf 10 or unloading the article F stored on the shelf 10. Note that the storage device 1 is, for example, a so-called automated warehouse that automatically unloads and loads the article F by the stacker crane 30.
[0018] Hereinafter, the schematic configuration of the storage device 1 according to the present embodiment will be described. As shown in FIG. 1, the storage device 1 includes a lower rail 20, an upper rail 21, and a stacker crane 30. The storage device 1 may further include a shelf 10. Note that the stacker crane 30 is an example of the transport device of the present invention.
[0019] The lower rail 20 and the upper rail 21 are rails laid along the X direction. The lower rail 20 is a rail provided on the floor surface along the shelf 10. The upper rail 21 is a rail provided on the ceiling along the shelf 10. For example, the upper rail 21 is laid so as to be parallel to the lower rail 20 when viewed from the left-right direction. The left-right direction is a direction orthogonal to each of the vertical direction and the traveling direction, and is the Y direction in the drawing. The upper rail 21 and the lower rail 20 are, for example, metal rails, but the materials of the upper rail 21 and the lower rail 20 are not limited to metal, and any rigid body that allows the stacker crane 30 to travel may be used.
[0020] The stacker crane 30 travels in the traveling direction between the lower rail 20 and the upper rail 21. Hereinafter, the schematic configuration of the stacker crane 30 according to the present embodiment will be described. FIG. 1 shows a schematic view of the stacker crane 30 as viewed from the left-right direction.
[0021] The stacker crane 30 comprises a mast 31, a lower support section 32, an upper housing 33, an upper traveling section 34, a transfer device 35, a lower traveling section 36, a lifting platform 50, and a lifting device 60.
[0022] The mast 31 is a support column for the stacker crane 30 and is a columnar member extending vertically. A lower support portion 32 is provided at the lower end of the mast 31. In other words, the mast 31 is erected on the lower support portion 32. An upper traveling portion 34 is provided at the upper end of the mast 31 via an upper housing 33. The mast 31 can be any member extending vertically, and its material and shape are not particularly limited.
[0023] The lower support section 32 supports the lower end of the mast 31. The lower support section 32 also supports the lower running section 36. The upper housing 33 is provided at the upper end of the mast 31.
[0024] The upper running section 34 is provided on the upper part of the upper housing 33. The upper running section 34 runs on the upper rail 21. The upper running section 34 is, for example, a running bogie. The upper running section 34 has an upper support section 40 which includes running wheels 41, driven rollers 42, and a pair of guide rollers 43.
[0025] The upper support section 40 supports the running wheels 41, the driven rollers 42, and a pair of guide rollers 43. The running wheels 41 and the driven rollers 42 are supported as a pair on the upper part of the upper support section 40. The running wheels 41 and the driven rollers 42 sandwich the upper rail 21 in the left-right direction and roll along the upper rail 21. For example, the running wheels 41 are positioned on the +Y direction side of the upper rail 21, and the driven rollers 42 are positioned on the -Y direction side. The running wheels 41 are driven by the upper drive section 44 (for example, an electric motor), and the running wheels 41 and the driven rollers 42 roll while in contact with the side surface of the upper rail 21.
[0026] The pair of guide rollers 43 are provided on either side of the upper rail 21 in the left-right direction. The pair of guide rollers 43 are provided behind or in front of the running wheels 41 in the direction of travel. The pair of guide rollers 43 guide the upper running section 34 so that it does not swing from side to side relative to the upper rail 21.
[0027] The transfer device 35 transfers items F between the shelf 10 and the stacker crane 30 using a multi-joint arm that supports the items F. Here, transfer includes both or either unloading the items F onto the shelf 10 and / or gripping the items F placed on the shelf 10. The transfer device 35 is raised and lowered by the lifting device 60. That is, the transfer device 35 is raised and lowered along the mast 31. The transfer device 35 is, for example, a sliding fork type transfer device. The general configuration of the transfer device 35 will be described below.
[0028] As shown in Figure 1, the transfer device 35 comprises, for example, a holding section 35A, an arm section 35B, and a swivel drive section 35C. The holding section 35A is provided on the upper part of the lifting platform 50 of the lifting device 60. The holding section 35A holds the article F. The method of holding the article F by the holding section 35A is not particularly limited, but for example, it is held by supporting the bottom surface of the article F.
[0029] The arm section 35B is connected to the holding section 35A. The arm section 35B is, for example, a multi-joint arm. The base end of the arm section 35B is connected to the lifting platform 50, and the tip end is connected to the holding section 35A. When the transfer device 35 is not performing a transfer, it folds the arm section 35B. When the transfer device 35 is performing a transfer, it extends the arm section 35B. With this configuration, the arm section 35B extends and retracts horizontally. The drive source (for example, an electric motor) that rotates the extension and retraction axis of the arm section 35B is, for example, mounted on the upper part of the lifting platform 50.
[0030] The swivel drive unit 35C is located at the bottom of the lifting platform 50. The swivel drive unit 35C rotates the arm 35B in the horizontal direction. The swivel drive unit 35C includes a mechanism for rotating the arm 35B. The swivel drive unit 35C includes, for example, an electric motor, a pulley, and a swivel shaft, and transmits the rotational force of the electric motor to the swivel shaft via the pulley.
[0031] The lower running section 36 is supported by the lower support section 32. The lower running section 36 runs on the lower rail 20. The lower running section 36 may be located, for example, directly below the mast 31, or it may be positioned offset to the left or right relative to the mast 31. In the example shown in Figure 1, a part of the lower running section 36 is located inside the lower support section 32. The lower running section 36 is equipped with at least running wheels.
[0032] The lifting platform 50 is positioned on one side in the direction of travel. The lifting platform 50 moves vertically up and down on one side of the mast 31 in the direction of travel. The one side in the direction of travel is the -X direction in the figure. Note that the lifting platform 50 is just one example of a lifting mechanism.
[0033] As shown in Figures 1 and 2, the lifting platform 50 comprises a mounting section 51, a first member 52, and a second member 53.
[0034] The mounting portion 51 is a base for supporting the article F from below. The article F is placed on top of the mounting portion 51. The shape of the mounting portion 51 is, for example, plate-like. The upper and lower surfaces of the mounting portion 51 are, for example, parallel to the XY plane.
[0035] The first member 52 extends upward from the end of the mounting portion 51. For example, the first member 52 extends in the +Z direction from the +X direction end of the mounting portion 51.
[0036] The second member 53 extends horizontally from the upper part of the first member 52. In one example of this embodiment, the second member 53 protrudes from the upper part of the first member 52 in both the ±Y direction. The upper part of the first member 52 refers to the portion that includes a certain range in the -Z direction from the upper end of the first member 52. The second member 53 that protrudes from the upper part of the first member 52 in the +Y direction may be referred to as "second member 53a," and the second member 53 that protrudes from the upper part of the first member 52 in the -Y direction may be referred to as "second member 53b."
[0037] The lifting device 60 comprises a linear guide (linear motion guide mechanism) 61, a lifting rotating body 62, a detection device 63, two suspension mechanisms 64 (first suspension mechanism 64a and second suspension mechanism 64b), and a balance weight 65 (see, for example, Figures 1 to 3).
[0038] As shown in Figure 1, the linear guide 61 comprises a lifting rail 611 and a lifting block 612.
[0039] The lifting rail 611 is a long linear guide rail extending vertically. The lifting rail 611 is installed on one side of the mast 31 in the direction of travel. For example, the lifting rail 611 is installed vertically along almost the entire length of the mast 31. In this embodiment, as an example, only one lifting rail 611 is installed on one side of the mast 31 in the direction of travel. However, this is not the only example, and there are no particular limitations on the number of lifting rails 611.
[0040] The lifting block 612 moves linearly back and forth along the lifting rail 611. The lifting block 612 is slidably engaged with the lifting rail 611. The first member 52 of the lifting platform 50 is connected to the lifting block 612. This allows the lifting platform 50 to move smoothly back and forth. When the first member 52 is fixed to the lifting block 612, the planes (upper and lower surfaces) of the mounting section 51 are parallel to the horizontal plane. The lifting block 612 is sometimes referred to as a carriage.
[0041] The lifting and lowering rotating body 62 is, for example, located on the top of the mast 31. The lifting and lowering rotating body 62 is housed in the upper housing 33. The lifting and lowering rotating body 62 is, for example, a pulley or a sprocket. The lifting and lowering rotating body 62 may be provided for each suspension mechanism 64. The lifting device 60 includes, for example, a lifting motor that rotates the lifting and lowering rotating body 62, and moves the lifting platform 50 vertically by rotating the lifting and lowering rotating body 62. For example, the lifting device 60 lowers the lifting platform 50 by rotating the lifting and lowering rotating body 62 in a first direction, and raises the lifting platform 50 by rotating the lifting and lowering rotating body 62 in a second direction opposite to the first direction.
[0042] The detection device 63 detects an abnormality in the suspension mechanism 64. The abnormality in the suspension mechanism 64 may be an abnormality in the first suspension mechanism 64a, an abnormality in the second suspension mechanism 64b, or both. In this embodiment, the detection device 63 detects the abnormality if an abnormality occurs in either the first suspension mechanism 64a or the second suspension mechanism 64b. The detection device 63 does not detect whether the abnormality occurred in the first suspension mechanism 64a or the second suspension mechanism 64b. An abnormality in the suspension mechanism 64 includes an abnormality in one or more suspension members 71. An abnormality in a suspension member 71 may be, for example, an abnormal elongation of one or more suspension members 71, a skipped tooth in one or more suspension members 71, a cut in one or more suspension members 71, or a phase shift between multiple suspension members.
[0043] As an example of this embodiment, the detection device 63 is attached to the lifting platform 50. Specifically, the detection device 63 is provided at the upper end of the first member 52. An example of the configuration of the detection device 63 will be described below.
[0044] The detection device 63 includes, for example, a light-emitting unit 90 that emits light (hereinafter referred to as "inspection light") and a light-receiving unit 91 that receives the inspection light emitted by the light-emitting unit 90 (see, for example, Figures 4 and 5). The light-emitting unit 90 and the light-receiving unit 91 are arranged to face each other. In the example shown in Figure 2, the detection device 63 includes a U-shaped photoelectric sensor in which the light-emitting unit 90 and the light-receiving unit 91 are arranged to face each other in the Y direction.
[0045] The detection device 63 detects an abnormality in the suspension mechanism 64 when the light emitted from the light emitter 90 toward the light receiver 91 is blocked. When the light emitted from the light emitter 90 toward the light receiver 91 is blocked, the detection device 63 outputs a first signal. The first signal is a signal indicating an abnormality in the suspension mechanism 64, and is, for example, a voltage signal above a first threshold. The output of the first signal is one example of the detection of an abnormality in the suspension mechanism 64.
[0046] On the other hand, if the light emitted from the light-emitting unit 90 toward the light-receiving unit 91 is received by the light-receiving unit 91 without being obstructed, the detection device 63 outputs a second signal different from the first signal. The second signal is a signal indicating that no abnormality has occurred in the suspension mechanism 64, and is, for example, a voltage signal below a second threshold. The second threshold is a value below the first threshold. The output of the second signal is one example of the fact that no abnormality in the suspension mechanism 64 has been detected.
[0047] Each of the two suspension mechanisms 64 (first suspension mechanism 64a and second suspension mechanism 64b) supports the lifting platform 50 by suspending it in the vertical direction. Each of the first suspension mechanism 64a and second suspension mechanism 64b has the same configuration. In the example shown below, the lifting device 60 has two suspension mechanisms 64, namely the first suspension mechanism 64a and the second suspension mechanism 64b. However, it is not limited to this, and the lifting device 60 may have multiple suspension mechanisms 64, for example, three or more suspension mechanisms 64.
[0048] When the first suspension mechanism 64a and the second suspension mechanism 64b are not distinguished, they may simply be referred to as "suspension mechanism 64". In addition, to distinguish multiple identical components from one another, the letter "a" may be added to the end of the reference numeral for each component of the first suspension mechanism 64a, and the letter "b" may be added to the end of the reference numeral for each component of the second suspension mechanism 64b. When multiple identical components are not distinguished from one another, the letters "a" and "b" may be omitted.
[0049] The following describes an example of the configuration of the suspension mechanism 64 according to this embodiment.
[0050] The suspension mechanism 64 includes, for example, a suspension member 71, a sliding part 72, an elastic member 73, and a light-shielding part 74 (see, for example, Figures 2 to 4).
[0051] The suspension members 71 suspend the lifting platform 50. One end of the suspension member 71 is connected to the sliding part 72, and the other end is connected to the balance weight 65. The middle section of each suspension member 71 is wrapped around the lifting rotating body 62. The middle section of each suspension member 71 is the space between one end of the suspension member 71 and the other end of the suspension member 71. Each suspension member 71 is, for example, a chain, wire, or belt.
[0052] The sliding portion 72 is capable of sliding vertically relative to the lifting platform 50. The sliding portion 72 comprises, for example, a shaft 80, a gripping portion 81, and a receiving portion 82.
[0053] The shaft 80 is inserted into each of the through holes HO formed in each of the second members 53. The through holes HO penetrate the second member 53 from the top surface to the bottom surface. The through holes HO are formed in both the second member 53a and the second member 53b. The shaft 80a is inserted into the through hole HO of the second member 53a. The shaft 80b is inserted into the through hole HO of the second member 53b. The shaft 80 is inserted into the through hole HO and is positioned to extend in the vertical direction.
[0054] The gripping portion 81 is fixed to the upper end of each shaft 80. The gripping portion 81 grips one end of the suspension member 71. The gripping portion 81 is, for example, a clamp, and is fixed by clamping one end of the suspension member 71. When the shaft 80 is inserted into the through hole HO of the second member 53, the gripping portion 81 is provided at the upper end of the shaft 80 and is located above the second member 53.
[0055] The receiving portion 82 is provided at the lower end of each shaft 80. The receiving portion 82 receives the lower end of the elastic member 73. The shape of the receiving portion 82 is not particularly limited, but in the example shown in Figure 2, it is disc-shaped. The diameter of the receiving portion 82 is larger than the diameter of the shaft 80. The upper surface of the receiving portion 82 is fixed to the lower end of the shaft 80. When the shaft 80 is inserted into the through hole HO of the second member 53, the receiving portion 82 is provided at the lower end of the shaft 80 and is located below the second member 53.
[0056] The elastic members 73 are provided between a part of the lifting platform 50 and a part of the sliding section 72a, and between a part of the lifting platform 50 and a part of the sliding section 72b. The elastic member 73 provided between a part of the lifting platform 50 and a part of the sliding section 72a may be referred to as "elastic member 73a," and the elastic member 73 provided between a part of the lifting platform 50 and a part of the sliding section 72b may be referred to as "elastic member 73b." The elastic member 73a expands and contracts in response to the tensile force of the suspension member 71a. The elastic member 73b expands and contracts in response to the tensile force of the suspension member 71b.
[0057] A portion of the lifting platform 50 is, for example, the lower surface of the second member 53. A portion of the sliding portion 72 is, for example, the receiving portion 82. The elastic member 73a is provided, for example, between the lower surface of the second member 53a and the receiving portion 82a. When the tensile force of the suspension member 71a changes, the sliding portion 72a and the lifting platform 50 slide relative to each other in the vertical direction. The elastic member 73a contracts or expands according to the relative positional relationship between the sliding portion 72a and the lifting platform 50 that has changed due to the sliding movement.
[0058] For example, if an abnormality occurs in the suspension member 71a, the tensile force of the suspension member 71a decreases. When the tensile force of the suspension member 71a decreases, the restoring force of the elastic member 73a causes the sliding part 72a to slide downward relative to the lifting platform 50.
[0059] The elastic member 73b is provided, for example, between the lower surface of the second member 53b and the receiving portion 82b. When the tensile force of the suspension member 71b fluctuates, the sliding portion 72b and the lifting platform 50 slide relative to each other in the vertical direction. The elastic member 73b contracts or expands in accordance with the relative positional relationship between the sliding portion 72b and the lifting platform 50 that has changed due to the sliding movement.
[0060] For example, if an abnormality occurs in the suspension member 71b, the tensile force of the suspension member 71b decreases. When the tensile force of the suspension member 71b decreases, the restoring force of the elastic member 73b causes the sliding part 72b to slide downward relative to the lifting platform 50.
[0061] The elastic member 73 is, for example, a compression spring and is provided around the shaft 80 between the lower surface of the second member 53 and the receiving portion 82. However, it is not limited to this, and the elastic member 73 may be, for example, silicone rubber. In other words, the elastic member 73 can be any member to which elastic force is applied.
[0062] The light-shielding portion 74 is displaced vertically in accordance with the expansion and contraction of the elastic member 73. For example, the light-shielding portion 74 is fixed to each of the sliding portions 72 and is displaced vertically in accordance with the sliding movement of the sliding portions 72. The light-shielding portion 74 can block the inspection light by moving vertically. In one example of this embodiment, the light-shielding portion 74 can block the inspection light by moving downward. The light-shielding portion 74 is not particularly limited as long as it has a shape that can block the inspection light, but as an example, it has an L-shaped tip (see, for example, Figure 5).
[0063] The light-shielding portion 74a is fixed to the gripping portion 81a, for example. The light-shielding portion 74a is out of the optical path LP of the inspection light when the tensile force of the suspension member 71a is within the normal range. When the tensile force of the suspension member 71a changes from within the normal range to outside the normal range, the light-shielding portion 74a is displaced onto the optical path LP of the inspection light, thereby blocking the inspection light emitted from the light-emitting portion 90 toward the light-receiving portion 91. A change in the tensile force of the suspension member 71a from within the normal range to outside the normal range occurs, for example, when an abnormality occurs in the suspension member 71a.
[0064] The light-shielding portion 74b is fixed to the gripping portion 81b, for example. The light-shielding portion 74b is out of the optical path LP of the inspection light when the tensile force of the suspension member 71b is within the normal range. When the tensile force of the suspension member 71b changes from within the normal range to outside the normal range, the light-shielding portion 74b is displaced onto the optical path LP of the inspection light, thereby blocking the inspection light emitted from the light-emitting portion 90 toward the light-receiving portion 91. A change in the tensile force of the suspension member 71b from within the normal range to outside the normal range occurs, for example, when an abnormality occurs in the suspension member 71b.
[0065] In this manner, if an abnormality such as elongation or breakage occurs in the suspension member 71a, the light-shielding part 74a moves between the light-emitting part 90 and the light-receiving part 91, so the inspection light is blocked by the light-shielding part 74a, and the detection device 63 detects an abnormality in the suspension mechanism 64. Similarly, if an abnormality such as elongation or breakage occurs in the suspension member 71b, the light-shielding part 74b moves between the light-emitting part 90 and the light-receiving part 91, so the inspection light is blocked by the light-shielding part 74b, and the detection device 63 detects an abnormality in the suspension mechanism 64.
[0066] As shown in Figure 1, the balance weight 65 is suspended by two suspension members 71 on the other side of the mast 31 in the direction of travel (for example, the +X direction). The balance weight 65 is also provided on the other side of the mast 31 in the direction of travel so as to be able to move up and down. The balance weight 65 adjusts the weight balance and is an example of the adjustment part of the present invention.
[0067] The abnormality detection of the suspension mechanism 64 according to this embodiment will be described in detail below. The state of the suspension mechanism 64 shown in Figure 2 is a state in which no abnormality has occurred (hereinafter referred to as the "normal state").
[0068] When the first suspension mechanism 64a and the second suspension mechanism 64b are supporting the lifting platform 50, in a normal state where no abnormalities occur in either the first suspension mechanism 64a or the second suspension mechanism 64b, the tensile force of the suspension member 71a and the tensile force of the suspension member 71b are within the normal range (Figure 2). In a normal state, both the elastic member 73a and the elastic member 73b are contracted beyond their natural length, and the light-shielding parts 74a and 74b are located above the optical path LP of the inspection light. Since the amount of contraction of the elastic member 73a and the elastic member 73b is approximately the same in a normal state, the gripping parts 81a and 81b are located at approximately the same height.
[0069] Under normal conditions, the light-shielding sections 74a and 74b are not positioned to block the inspection light, so the detection device 63 outputs a second signal, which indicates that there is no abnormality in the suspension mechanism 64.
[0070] Now, let's assume that an abnormality such as elongation or breakage occurs in the suspension member 71b of the second suspension mechanism 64b. Figure 6 shows the state in which an abnormality has occurred in the suspension member 71b (hereinafter referred to as the "abnormal state").
[0071] If an abnormality such as elongation or breakage occurs in the suspension member 71b, the tensile force of the suspension member 71b decreases and falls outside the normal range. When the tensile force of the suspension member 71b falls outside the normal range, the restoring force of the elastic member 73b causes the sliding part 72b to slide downward relative to the lifting platform 50. That is, the gripping part 81b moves downward and approaches the upper end (second member 53b) of the lifting platform 50.
[0072] The light-shielding portion 74b is fixed to the sliding portion 72b. Therefore, when the gripping portion 81b moves downward, the light-shielding portion 74b is displaced downward toward the optical path LP of the inspection light and enters the optical path LP between the light-emitting portion 90 and the light-receiving portion 91. The light-shielding portion 74b then blocks the inspection light emitted from the light-emitting portion 90 toward the light-receiving portion 91 (Figure 6). As a result, the amount of inspection light received by the light-receiving portion 91 decreases or the inspection light can no longer be received, and the detection device 63 outputs a first signal, which is a signal indicating an abnormality in the suspension mechanism 64. In other words, the detection device 63 detects an abnormality in the suspension mechanism 64. Although the example given illustrates the detection of an abnormal condition occurring in the suspension member 71b, the detection device 63 is not limited to this. The detection device 63 can detect abnormalities in the suspension member 71b, and can also detect abnormalities in both suspension members 71a and 71b.
[0073] In the example described above, the case in which a part of the lifting platform 50 is the lower surface of the second member 53 was explained as an example, but the invention is not limited to this. For example, a part of the lifting platform 50 may be a part of the second member 53 other than the lower surface of the second member 53 (for example, the upper surface), a part of the first member 52 (for example, the upper surface or side surface), or a part of the mounting portion 51. In the example described above, the case in which a part of the sliding portion 72 is the receiving portion 82 was explained as an example, but the invention is not limited to this. A part of the sliding portion 72 may be a part other than the receiving portion 82, such as the shaft 80 or the gripping portion 81.
[0074] Thus, in the conveying device according to this embodiment, one detection device can detect abnormalities in one or more suspended members 71. Therefore, there is no need to provide multiple detection devices for each suspended member 71, and abnormalities in the suspended members 71 can be detected at low cost.
[0075] The above embodiment discloses the following configuration. (Composition 1) A lifting mechanism (for example, a lifting platform 50) that supports the item F, It includes a lifting device 60 that raises and lowers the lifting section in the vertical direction, The lifting device 60 is Multiple suspension mechanisms 64 that support the lifting section so that it can move up and down in the vertical direction, It includes one detection device 63 for detecting abnormalities in the suspension mechanism 64, The detection device 63 is A light-emitting unit 90 that emits inspection light, It comprises a light-receiving unit 91 that receives inspection light, Each suspension mechanism 64 is: A suspension member 71 that suspends the lifting mechanism, An elastic member 73 that expands and contracts in response to the tensile force of the suspension member 71, It comprises a light-shielding portion 74 that is displaced vertically in accordance with the expansion and contraction of the elastic member 73, Each light-shielding section 74 is located outside the optical path LP of the inspection light when the tensile force of the suspension member 71 is within the normal range, and is displaced onto the optical path LP of the inspection light when the tensile force of the suspension member 71 changes from within the normal range to outside the normal range, in a conveying device (e.g., a stacker crane 30). (Configuration 2) A lifting mechanism is connected to one end of each of the multiple suspension members 71, and an adjustment mechanism (for example, a balance weight 65) for adjusting the weight balance is connected to the other end of each of the multiple suspension members 71. The conveying device described in Configuration 1. (Composition 3) Each suspension mechanism 64 is equipped with a sliding part 72 that can slide vertically relative to the lifting part. One end of the suspension member 71 is connected to the slide portion 72. The elastic member 73 is provided between a part of the lifting section and a part of the sliding section 72, and contracts or expands according to the relative positional relationship between the sliding section 72 and the lifting section in the vertical direction. The relative position changes as the sliding part 72 and the lifting part slide relative to each other due to fluctuations in tensile force. A conveying device as described in configuration 1 or configuration 2. (Composition 4) The lifting mechanism is, A mounting section 51 on which item F is placed, A first member 52 extending upward from the end of the mounting section, The first member 52 comprises a second member 53 extending horizontally from its upper part, The slide portion 72 is A shaft 80 is inserted into a through hole formed in the second member 53 and extends in the vertical direction, A gripping portion 81 is provided at the upper end of the shaft 80 and grips the end of the suspension member 71, It comprises a receiving portion 82 provided at the lower end of the shaft 80, The elastic member 73 is provided between the lower surface of the second member 53 and the receiving portion 82. A conveying device as described in any of configurations 1 to 3. (Composition 5) When the tensile force is within the normal range, the elastic member 73 contracts beyond its natural length, and the light-shielding portion 74 is positioned above the optical path LP of the inspection light. If the tensile force changes from within the normal range to outside the normal range, the elastic member 73 stretches, and the light-shielding portion 74 is displaced downward toward the optical path LP of the inspection light. A conveying device as described in any of configurations 1 to 4. (Composition 6) The detection device 63 is provided at the upper end of the first member 52, The light-shielding portion 74 is provided on each of the multiple gripping portions 81. A conveying device as described in any of configurations 1 to 5.
[0076] One or more of the requirements described in the embodiments described above may be omitted. Furthermore, the requirements described in the embodiments described above can be combined as appropriate. Also, the execution order of each procedure shown in this embodiment can be implemented in any order, as long as the result of the previous procedure is not used in a later procedure. Furthermore, even if the operations in the embodiments described above are described using terms such as "first," "next," and "followed by," it is not necessary to perform them in this order. [Explanation of symbols]
[0077] 30...Stacker crane, 50...Lifting platform, 60...Lifting device, 63...Detection device, 64...Suspension mechanism, 71...Suspension member, 73...Elastic member, 74...Light shielding part, 90...Light emitting part, 91...Light receiving part
Claims
1. A lifting mechanism that supports the item, The lifting device comprises a lifting mechanism for raising and lowering the lifting section in the vertical direction, The aforementioned lifting device is Multiple suspension mechanisms that support the lifting section so that it can move up and down in the vertical direction, The system includes one detection device for detecting abnormalities in the suspension mechanism, The detection device is A light-emitting unit that emits inspection light, The system includes a light-receiving unit that receives the aforementioned inspection light, Each of the aforementioned suspension mechanisms is, A suspension member for suspending the aforementioned lifting mechanism, An elastic member that expands and contracts in response to the tensile force of the suspension member, The elastic member comprises a light-shielding portion that is displaced in the vertical direction in accordance with the expansion and contraction of the elastic member, Each of the aforementioned light-shielding parts is outside the optical path of the inspection light when the tensile force is within the normal range, and is displaced onto the optical path of the inspection light when the tensile force changes from within the normal range to outside the normal range. Each of the suspension mechanisms is equipped with a sliding part that can slide in the vertical direction relative to the lifting part, One end of the suspension member is connected to the sliding portion. The elastic member is provided between a part of the lifting section and a part of the sliding section, and contracts or expands according to the relative positional relationship between the sliding section and the lifting section in the vertical direction. The aforementioned positional relationship changes as the sliding part and the lifting part slide relative to each other due to fluctuations in the tensile force in the conveying device.
2. Each of the multiple suspension members is connected to one end of the lifting mechanism, and each of the multiple suspension members is connected to the other end of the adjustment mechanism for adjusting the weight balance. The conveying device according to claim 1.
3. The aforementioned lifting mechanism is A mounting section on which the aforementioned article is placed, A first member extending upward from the end of the mounting portion, The first member comprises a second member extending horizontally from the upper part of the first member, The aforementioned sliding portion is A shaft is inserted into a through hole formed in the second member and extends in the vertical direction, A gripping portion is provided at the upper end of the shaft and grips the end of the suspension member, The shaft comprises a receiving portion provided at the lower end of the shaft, The elastic member is provided between the lower surface of the second member and the receiving portion. The conveying device according to claim 1.
4. When the tensile force is within the normal range, the elastic member contracts beyond its natural length, and the light-shielding portion is positioned above the optical path of the inspection light. If the tensile force changes from within the normal range to outside the normal range, the elastic member stretches and the light-shielding portion is displaced downward toward the optical path of the inspection light. A conveying device according to any one of claims 1 to 3.
5. The detection device is provided at the upper end of the first member, The light-shielding portion is provided on each of the plurality of gripping portions, as described in claim 3.