Conveyance device

Abstract

To provide a conveyance device capable of detecting abnormality of a hanging member at a low cost.SOLUTION: A conveyance device includes: a lifting part for supporting an article F; and a lifting device 60 for moving up / down the lifting part in a vertical direction. The lifting device 60 includes: a plurality of hanging mechanisms 64 for supporting the lifting part so as to move up / down in the vertical direction; and one detection device 63 for detecting abnormality of the hanging mechanism 64. The detection device 63 includes: a light projecting part 90 for projecting inspection light; and a light receiving part 91 for receiving the inspection light. Each hanging mechanism 64 includes: a hanging member 71 for hanging the lifting part; an elastic member 73 expanding / contracting according to a tensile force of the hanging member 71; and a light shielding part 74 displaced in the vertical direction according to the expansion / contraction of the elastic member 73. Each light shielding part 74 is deviated from an optical path LP of the inspection light in the case where the tensile force is within a normal range, and is displaced on the optical path LP of the inspection light in the case where the tensile force changes from within the normal range to the outside the normal range.SELECTED DRAWING: Figure 1

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 an object to be conveyed, 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 to a conveying device that suspends and supports a lifting part with a plurality of suspension members.

[0005] An object of the present invention is to provide a conveying device that can detect an abnormality of a suspension member at low cost.

Means for Solving the Problems

[0006] The conveying device according to an aspect of the present invention includes a lifting part that supports an article, and a lifting device that moves the lifting part up and down in the vertical direction. The lifting device includes a plurality of suspension mechanisms that support the lifting part so as to be movable up and down in the vertical direction, and one detection device that detects an abnormality in the suspension mechanism. The detection device includes a light projecting part that projects inspection light, and a light receiving part that receives the inspection light. Each suspension mechanism includes a suspension member that suspends the lifting part, an elastic member that expands and contracts according to the tensile force of the suspension member, and a light shielding part that is displaced in the vertical direction according to the expansion and contraction of the elastic member. Each light shielding part is out of 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.

Effect of the Invention

[0007] In the conveying device according to an aspect of the present invention, when an abnormality occurs, such as a phase shift between a plurality of suspension members or damage to at least one suspension member, the tensile force of at least one suspension member can change outside the normal range. As a result, the inspection light is blocked by the displaced light shielding part, and the conveying device detects the abnormality with one detection device. Thereby, when detecting an abnormality, it is not necessary to provide a plurality of detection devices, so that the abnormality can be detected at low cost.

[0008] Further, in the conveying device according to the above aspect, a lifting part may be connected to one end of each of the plurality of suspension members, and an adjustment part for adjusting the weight balance may be connected to the other end of each of the plurality of suspension members. With such a configuration, it is possible to more appropriately detect an abnormality in the end suspension members where a phase shift is likely to occur.

[0009] Further, in the conveying device according to the above aspect, each suspension mechanism includes a slide portion that can slide in the vertical direction with respect to the lifting portion. One end of the suspension member is connected to the slide portion. The elastic member is provided between a part of the lifting portion and a part of the slide portion, and contracts or expands according to the relative positional relationship between the slide portion and the lifting portion in the vertical direction. The positional relationship may change even when the slide portion and the lifting portion slide relative to each other due to fluctuations in the tensile force. With such a configuration, the number of components required to detect abnormalities can be reduced compared to the prior art.

[0010] Further, in the conveying device according to the above aspect, the lifting portion includes a placement portion on which an article is placed, a first member extending upward from an end of the placement portion, and a second member extending horizontally from an upper portion of the first member. The slide portion includes a shaft inserted into a through hole formed in the second member and extending in the vertical direction, a gripping portion provided at an upper end of the shaft for gripping an end of the suspension member, and a receiving portion provided at a lower end of the shaft. The elastic member may be provided between the lower surface of the second member and the receiving portion.

[0011] Further, in the conveying device according to the above aspect, when the tensile force is within the normal range, the elastic member contracts more than its natural length, and the light-shielding portion is 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 expands, and the light-shielding portion may be displaced downward toward the optical path of the inspection light. Further, in the conveying device according to the above aspect, the detection device may be provided at an upper end portion of the first member, and the light-shielding portion may be provided at each of the plurality of gripping portions.

Brief Description of the Drawings

[0012]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Embodiments for Carrying Out the Invention

[0013] Hereinafter, the present invention will be described through embodiments. However, the following embodiments do not limit the invention according to the claims. Also, not all combinations of features described in the embodiments are essential for the solution means of the invention. In the drawings, the same or similar parts may be denoted by the same reference numerals, and duplicate explanations may be omitted. In addition, the shape and size of elements in the drawings may be exaggerated for clearer explanation, and thus may be different in shape and dimensions from actual products.

[0014] In the drawings, the directions in the figure may be described using the XYZ coordinate system. In the XYZ coordinate system, a 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 orthogonal to the X direction is denoted as the Y direction. Also, the direction perpendicular to the XY plane is denoted as the Z direction. In this embodiment, the Z direction in the figure is the vertical direction.

[0015] The storage device 1 transfers the article F between the stacker crane 30 and the shelf 10 for storing a plurality of articles F. The article F accommodates, for example, a semiconductor wafer or a reticle used in the manufacture of semiconductor elements. The article F is, for example, a FOUP (Front Opening Unified Pod), a SMIF Pod, or a reticle Pod whose interior can be purged.

[0016] The shelf 10 is installed, for example, on the floor surface in the clean room. The shelf 10 is arranged side by side on one side or both sides of the traveling direction of the stacker crane 30 (hereinafter simply referred to as the "traveling direction"). The traveling direction is the X direction in the figure.

[0017] The storage device 1 temporarily stores an article F such as a FOUP on a shelf 10, and in response to a request from a 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) within 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 loads and unloads 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 figure. 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 includes a mast 31, a lower support portion 32, an upper housing 33, an upper traveling portion 34, a transfer device 35, a lower traveling portion 36, a lift table 50, and a lifting device 60.

[0022] The mast 31 is a column of the stacker crane 30 and is a columnar member extending in the vertical direction. A lower support portion 32 is provided at the lower end of the mast 31. In other words, the mast 31 stands on the lower support portion 32. An upper traveling portion 34 is provided at the upper end of the mast 31 via the upper housing 33. Note that the mast 31 only needs to be a member extending in the vertical direction, and its material and shape are not particularly limited.

[0023] The lower support portion 32 supports the lower end of the mast 31. Also, the lower support portion 32 supports the lower traveling portion 36. The upper housing 33 is provided at the upper end of the mast 31.

[0024] The upper traveling portion 34 is provided on the upper part of the upper housing 33. The upper traveling portion 34 travels on the upper rail 21. The upper traveling portion 34 is, for example, a traveling carriage. The upper traveling portion 34 and the upper support portion 40 include traveling wheels 41, driven rollers 42, and a pair of guide rollers 43.

[0025] The upper support portion 40 supports the traveling wheels 41, the driven rollers 42, and the pair of guide rollers 43. The traveling wheels 41 and the driven rollers 42 are supported in a pair at the upper part of the upper support portion 40. The traveling wheels 41 and the driven rollers 42 sandwich the upper rail 21 in the left - right direction and roll along the upper rail 21. The traveling wheels 41 are arranged, for example, on the +Y - direction side of the upper rail 21, and the driven rollers 42 are arranged on the -Y - direction side. The traveling wheels 41 are driven by an upper drive portion 44 (for example, an electric motor), and the traveling wheels 41 and the driven rollers 42 roll while contacting the side surface of the upper rail 21.

[0026] A pair of guide rollers 43 are provided with the upper rail 21 interposed therebetween in the left - right direction. The pair of guide rollers 43 are provided behind or in front of the traveling wheels 41 in the traveling direction. The pair of guide rollers 43 guide the upper traveling part 34 so as not to swing in the left - right direction with respect to the upper rail 21.

[0027] The transfer device 35 performs transfer between the shelf 10 and the stacker crane 30 by means of an articulated arm that supports the article F. Here, transfer includes either or both of unloading the article F onto the shelf 10 and picking up the article F placed on the shelf 10. The transfer device 35 is lifted and lowered by a lifting device 60. That is, the transfer device 35 moves up and down along the mast 31. The transfer device 35 is, for example, a slide - fork type transfer device. The schematic configuration of the transfer device 35 will be described below.

[0028] As shown in FIG. 1, the transfer device 35 includes, for example, a holding part 35A, an arm part 35B, and a swivel drive part 35C. The holding part 35A is provided on the upper part of the lift table 50 of the lifting device 60. The holding part 35A holds the article F. The method of holding the article F by the holding part 35A is not particularly limited, but for example, it holds by supporting the bottom surface of the article F.

[0029] The arm part 35B is connected to the holding part 35A. The arm part 35B is, for example, an articulated arm. The base end side of the arm part 35B is connected to the lift table 50, and the tip end side is connected to the holding part 35A. When the transfer device 35 does not perform transfer, the arm part 35B is folded. And when the transfer device 35 performs transfer, the arm part 35B is deployed. With such a configuration, the arm part 35B expands and contracts in the horizontal direction. The drive source (for example, an electric motor) for rotating the expansion - contraction axis of the arm part 35B is, for example, attached to the upper part of the lift table 50.

[0030] The swivel drive unit 35C is provided at the lower part of the lifting platform 50. The swivel drive unit 35C swivels the arm part 35B in the horizontal direction. The swivel drive unit 35C includes a mechanism for swiveling the arm part 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 traveling unit 36 is supported by the lower support part 32. The lower traveling unit 36 travels on the lower rail 20. The lower traveling unit 36 may be provided, for example, directly below the mast 31, or may be arranged in a state shifted in the left - right direction with respect to the mast 31. In the example shown in FIG. 1, a part of the lower traveling unit 36 is provided inside the lower support part 32. The lower traveling unit 36 includes at least traveling wheels.

[0032] The lifting platform 50 is arranged on one side in the traveling direction. The lifting platform 50 moves up and down vertically on one side in the traveling direction of the mast 31. One side in the traveling direction is the - X direction in the figure. Note that the lifting platform 50 is an example of a lifting part.

[0033] As shown in FIGS. 1 and 2, the lifting platform 50 includes a placement part 51, a first member 52, and a second member 53.

[0034] The placement part 51 is a base for supporting the article F from below. The article F is placed above the placement part 51. The shape of the placement part 51 is, for example, plate - shaped. The upper surface and the lower surface of the placement part 51 are parallel to the XY plane, for example.

[0035] The first member 52 extends upward from the end of the placement part 51. For example, the first member 52 extends in the +Z direction from the end of the placement part 51 in the +X direction.

[0036] The second member 53 extends horizontally from the upper part of the first member 52. As an example of the present embodiment, the second member 53 protrudes from the upper part of the first member 52 in the respective +Y and -Y directions. The upper part of the first member 52 means a part including a certain range in the -Z direction from the upper end of the first member 52. Note that the second member 53 protruding 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 protruding 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 includes a linear guide (linear motion guiding mechanism) 61, a lifting and 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, FIGS. 1 to 3).

[0038] As shown in FIG. 1, the linear guide 61 includes a lifting rail 611 and a lifting block 612.

[0039] The lifting rail 611 is a long linear guide rail extending in the vertical direction. The lifting rail 611 is provided on one side in the traveling direction of the mast 31. For example, the lifting rail 611 is vertically attached over substantially the entire length of the mast 31. In the present embodiment, as an example, only one lifting rail 611 is attached to one side in the traveling direction of the mast 31. However, it is not limited thereto, and the number of the lifting rails 611 is not particularly limited.

[0040] The lifting block 612 linearly reciprocates on the lifting rail 611. The lifting block 612 slidably engages with the lifting rail 611. The first member 52 of the lifting platform 50 is connected to the lifting block 612. Thereby, the lifting platform 50 can smoothly reciprocate. When the first member 52 is fixed to the lifting block 612, the planes (upper surface and lower surface) of the mounting portion 51 are parallel to the horizontal plane. Note that the lifting block 612 may be called a carriage.

[0041] The lifting and rotating body 62 is provided, for example, at the upper part of the mast 31. The lifting and rotating body 62 is housed in the upper housing 33. The lifting and rotating body 62 is, for example, a pulley or a sprocket. The lifting and 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 rotating body 62, and moves the lifting platform 50 in the vertical direction by rotating the lifting and rotating body 62. For example, when the lifting device 60 rotates the lifting and rotating body 62 in the first direction, the lifting platform 50 is lowered, and when the lifting device 60 rotates the lifting and rotating body 62 in the second direction, which is the direction opposite to the first direction, the lifting platform 50 is raised.

[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. The detection device 63 in the present embodiment detects an abnormality when an abnormality occurs in either the first suspension mechanism 64a or the second suspension mechanism 64b. Note that the detection device 63 does not detect which of the first suspension mechanism 64a and the second suspension mechanism 64b the abnormality has occurred in. The abnormality in the suspension mechanism 64 includes an abnormality in one or more suspension members 71. The abnormality in the suspension member 71 is, for example, abnormal elongation of one or more suspension members 71, tooth skipping of one or more suspension members 71, cutting of one or more suspension members 71, or a phase shift between a plurality of suspension members.

[0043] As an example of the present embodiment, the detection device 63 is attached to the lifting platform 50. As a specific example, the detection device 63 is provided at the upper end of the first member 52. Hereinafter, a configuration example of the detection device 63 will be described.

[0044] The detection device 63 includes, for example, a light projecting unit 90 that projects light (hereinafter referred to as "inspection light") and a light receiving unit 91 that receives the inspection light projected by the light projecting unit 90 (see, for example, FIGS. 4 and 5). The light projecting unit 90 and the light receiving unit 91 are arranged to face each other. In the example shown in FIG. 2, the detection device 63 includes a U-shaped photoelectric sensor in which the light projecting unit 90 and the light receiving unit 91 are arranged to face each other in the Y direction.

[0045] When the light projected from the light projecting unit 90 toward the light receiving unit 91 is blocked, the detection device 63 detects an abnormality in the suspension mechanism 64. When the light projected from the light projecting unit 90 toward the light receiving unit 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 equal to or higher than a first threshold value. The output of the first signal is an example of the detection of an abnormality in the suspension mechanism 64.

[0046] On the other hand, when the light projected from the light projecting unit 90 toward the light receiving unit 91 is received by the light receiving unit 91 without being blocked, 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 equal to or lower than a second threshold value. The second threshold value is a value equal to or lower than the first threshold value. The output of the second signal is an example of the non-detection of an abnormality in the suspension mechanism 64.

[0047] Each of the two suspension mechanisms 64 (the first suspension mechanism 64a and the second suspension mechanism 64b) supports the lifting platform 50 by suspending it in the vertical direction. Each of the first suspension mechanism 64a and the second suspension mechanism 64b has the same configuration. In the example shown below, the lifting device 60 includes the first suspension mechanism 64a and the second suspension mechanism 64b, which are two suspension mechanisms 64. However, the present invention is not limited to this, and the lifting device 60 may include a plurality of suspension mechanisms 64, and may include, 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". Also, for the purpose of distinguishing a plurality of the same type of components from each other, an "a" may be added to the end of the reference numeral of each component of the first suspension mechanism 64a, and a "b" may be added to the end of the reference numeral of each component of the second suspension mechanism 64b. When a plurality of the same type of components are not distinguished from each other, the signs "a" and "b" may be omitted.

[0049] Hereinafter, a configuration example of the suspension mechanism 64 according to the present embodiment will be described.

[0050] The hanging mechanism 64 includes, for example, a hanging lower member 71, a slide portion 72, an elastic member 73, and a light-shielding portion 74 (see, for example, FIGS. 2 to 4).

[0051] The hanging lower member 71 suspends the lifting platform 50. One end of the hanging lower member 71 is connected to the slide portion 72, and the other end is connected to the balance weight 65. The middle portion of each hanging lower member 71 is wound around the lifting and rotating body 62. The middle portion of each hanging lower member 71 is between one end and the other end of the hanging lower member 71. Each hanging lower member 71 is, for example, a chain, a wire, or a belt.

[0052] The slide portion 72 is capable of sliding in the vertical direction with respect to the lifting platform 50. The slide portion 72 includes, for example, a shaft 80, a gripping portion 81, and a receiving portion 82.

[0053] The shaft 80 is inserted into each through hole HO formed in each second member 53. The through hole HO penetrates the second member 53 from the upper surface to the lower surface. The through hole HO is formed in each of 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 arranged 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 hanging lower member 71. The gripping portion 81 is, for example, a clamp that fixes by sandwiching one end of the hanging lower member 71. In a state where 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 portion of the shaft 80 and is located above the second member 53.

[0055] The receiving part 82 is provided at the lower end of each shaft 80. The receiving part 82 receives the lower end part of the elastic member 73. The shape of the receiving part 82 is not particularly limited, but in the example shown in FIG. 2, it is a disk shape. The diameter of the receiving part 82 is larger than the diameter of the shaft 80. The upper surface of the receiving part 82 is fixed to the lower end part of the shaft 80. In a state where the shaft 80 is inserted into the through hole HO of the second member 53, the receiving part 82 is provided at the lower end part of the shaft 80 and is located below the second member 53.

[0056] The elastic members 73 are respectively provided between a part of the lifting table 50 and a part of the slide part 72a and between a part of the lifting table 50 and a part of the slide part 72b. The elastic member 73 provided between a part of the lifting table 50 and a part of the slide part 72a may be referred to as "elastic member 73a", and the elastic member 73 provided between a part of the lifting table 50 and a part of the slide part 72b may be referred to as "elastic member 73b". The elastic member 73a expands and contracts according to the tensile force of the suspension lower member 71a. The elastic member 73b expands and contracts according to the tensile force of the suspension lower member 71b.

[0057] A part of the lifting table 50 is, for example, the lower surface of the second member 53. A part of the slide part 72 is, for example, the receiving part 82. The elastic member 73a is provided, for example, between the lower surface of the second member 53a and the receiving part 82a. When the tensile force of the suspension lower member 71a fluctuates, the slide part 72a and the lifting table 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 slide part 72a and the lifting table 50 changed by the slide movement.

[0058] For example, when an abnormality occurs in the suspension lower member 71a, the tensile force of the suspension lower member 71a decreases. When the tensile force of the suspension lower member 71a decreases, the slide part 72a slides downward relative to the lifting table 50 by the restoring force of the elastic member 73a.

[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 hanging lower member 71b fluctuates, the slide portion 72b and the lifting table 50 slide relative to each other in the vertical direction. The elastic member 73b contracts or expands according to the relative positional relationship between the slide portion 72b and the lifting table 50 that has changed due to the slide movement.

[0060] For example, when an abnormality occurs in the hanging lower member 71b, the tensile force of the hanging lower member 71b decreases. When the tensile force of the hanging lower member 71b decreases, the slide portion 72b slides downward relative to the lifting table 50 due to the restoring force of the elastic member 73b.

[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 or the like. That is, the elastic member 73 may be any member to which an elastic force is applied.

[0062] The light-shielding portion 74 is displaced in the vertical direction according to the expansion and contraction of the elastic member 73. For example, the light-shielding portion 74 is fixed to each of the slide portions 72 and is displaced in the vertical direction according to the slide movement of the slide portion 72. The light-shielding portion 74 can shield the inspection light by moving in the vertical direction. As an example of the present embodiment, the light-shielding portion 74 can shield the inspection light by moving downward. The light-shielding portion 74 is not particularly limited as long as it has a shape capable of shielding the inspection light, but as an example, it has an L-shaped tip (see, for example, FIG. 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 hanging lower member 71a is within the normal range. When the tensile force of the hanging lower 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 to block the inspection light projected from the light projecting portion 90 toward the light receiving portion 91. The case where the tensile force of the hanging lower member 71a changes from within the normal range to outside the normal range is, for example, the case where an abnormality occurs in the hanging lower member 71a.

[0064] The light-shielding part 74b is fixed to, for example, the gripping part 81b. When the tensile force of the suspension lower member 71b is within the normal range, the light-shielding part 74b is out of the optical path LP of the inspection light. When the tensile force of the suspension lower member 71b changes from within the normal range to outside the normal range, the light-shielding part 74b is displaced onto the optical path LP of the inspection light, thereby blocking the inspection light projected from the light projecting part 90 toward the light receiving part 91. The case where the tensile force of the suspension lower member 71b changes from within the normal range to outside the normal range is, for example, the case where an abnormality occurs in the suspension lower member 71b.

[0065] As described above, when an abnormality such as abnormal elongation or breakage occurs in the suspension lower member 71a, the light-shielding part 74a moves between the light projecting part 90 and the light receiving part 91. Therefore, the inspection light is blocked by the light-shielding part 74a, and the detection device 63 detects an abnormality in the suspension mechanism 64. Further, when an abnormality such as abnormal elongation or breakage occurs in the suspension lower member 71b, the light-shielding part 74b moves between the light projecting part 90 and the light receiving part 91. Therefore, 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 FIG. 1, the balance weight 65 is suspended by two suspension lower members 71 on the other side (for example, the +X direction side) in the traveling direction of the mast 31. Further, the balance weight 65 is provided so as to be movable up and down on the other side in the traveling direction of the mast 31. The balance weight 65 adjusts the weight balance and is an example of the adjustment part of the present invention.

[0067] Hereinafter, the abnormality detection of the suspension mechanism 64 according to the present embodiment will be specifically described. The state of the suspension mechanism 64 shown in FIG. 2 is a state in which no abnormality has occurred (hereinafter referred to as the "normal state").

[0068] In a state where the first lowering mechanism 64a and the second lowering mechanism 64b support the lifting platform 50, in a normal state where no abnormality has occurred in both the first lowering mechanism 64a and the second lowering mechanism 64b, the tensile force of the lower suspension member 71a and the tensile force of the lower suspension member 71b are within the normal ranges respectively (Fig. 2). In the normal state, both the elastic member 73a and the elastic member 73b are contracted more than their natural lengths, and the light shielding portions 74a and 74b are located above the optical path LP of the inspection light. Since the contraction amounts of the elastic member 73a and the elastic member 73b in the normal state are substantially the same, the gripping portion 81a and the gripping portion 81b are located at substantially the same height.

[0069] In the normal state, since the light shielding portions 74a and 74b do not exist at positions where they block the inspection light, the detection device 63 outputs a second signal which is a signal indicating that no abnormality has occurred in the lowering mechanism 64.

[0070] Here, assume that an abnormality such as abnormal elongation or cutting has occurred in the lower suspension member 71b of the second lowering mechanism 64b. Fig. 6 is a diagram showing a state where an abnormality has occurred in the lower suspension member 71b (hereinafter referred to as "abnormal state").

[0071] When an abnormality such as abnormal elongation or cutting occurs in the lower suspension member 71b, the tensile force of the lower suspension member 71b decreases and deviates from the normal range. When the tensile force of the lower suspension member 71b deviates from the normal range, the slide portion 72b slides downward with respect to the lifting platform 50 by the restoring force of the elastic member 73b. That is, the gripping portion 81b moves downward and approaches the upper end portion (second member 53b) of the lifting platform 50.

[0072] The light-shielding part 74b is fixed to the sliding part 72b. Therefore, when the gripping part 81b moves downward, the light-shielding part 74b is displaced downward along with the movement toward the optical path LP of the inspection light, and enters onto the optical path LP between the light projecting part 90 and the light receiving part 91. Then, the light-shielding part 74b blocks the inspection light projected from the light projecting part 90 toward the light receiving part 91 (Fig. 6). As a result, the amount of the inspection light received by the light receiving part 91 decreases or the inspection light cannot be received, and the detection device 63 outputs a first signal which is a signal indicating an abnormality of the suspension mechanism 64. That is, the detection device 63 detects an abnormality of the suspension mechanism 64. Although the case where the detection device 63 detects an abnormal state occurring in the suspension member 71b has been illustrated, the present invention is not limited to this. The detection device 63 can detect an abnormality of the suspension member 71b, and can also detect an abnormality of both the suspension members 71a and 71b.

[0073] In the above-described example, the case where a part of the lifting platform 50 is the lower surface of the second member 53 has been described as an example, but the present 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 the side surface), or a part of the mounting part 51. In the above-described example, the case where a part of the sliding part 72 is the receiving part 82 has been described as an example, but the present invention is not limited to this. A part of the sliding part 72 may be a part other than the receiving part 82 such as the shaft 80 or the gripping part 81, for example.

[0074] As described above, in the transport device according to the present embodiment, one detection device can detect an abnormality of one or more suspension members 71. Therefore, it is not necessary to provide a plurality of detection devices for each of the suspension members 71, and an abnormality of the suspension members 71 can be detected at low cost.

[0075] The above embodiment discloses the following configuration. (Configuration 1) A lifting part (for example, the lifting platform 50) that supports the article F, A lifting device 60 that moves the lifting part up and down in the vertical direction, The lifting device 60, A plurality of suspension mechanisms 64 that support the elevating part so as to be vertically movable up and down, and one detection device 63 that detects an abnormality of the suspension mechanism 64. The detection device 63 includes a light projecting part 90 that projects inspection light, and a light receiving part 91 that receives the inspection light. Each suspension mechanism 64 includes a suspension member 71 that suspends the elevating part, an elastic member 73 that expands and contracts according to the tensile force of the suspension member 71, and a light shielding part 74 that is displaced vertically according to the expansion and contraction of the elastic member 73. Each light shielding part 74 is out of 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, a conveying device (for example, a stacker crane 30). (Configuration 2) The elevating part is connected to one end of each of the plurality of suspension members 71, and an adjusting part (for example, a balance weight 65) for adjusting the weight balance is connected to the other end of each of the plurality of suspension members 71. The conveying device according to Configuration 1. (Configuration 3) Each suspension mechanism 64 includes a slide part 72 that is slidable vertically with respect to the elevating part. One end of the suspension member 71 is connected to the slide part 72. The elastic member 73 is provided between a part of the elevating part and a part of the slide part 72, and contracts or expands according to the relative positional relationship between the slide part 72 and the elevating part in the vertical direction. The positional relationship changes by the relative sliding movement between the slide part 72 and the elevating part due to the fluctuation of the tensile force. The conveying device according to Configuration 1 or Configuration 2. (Configuration 4) The elevating part includes a placement part 51 on which an article F is placed, a first member 52 that extends upward from an end of the placement part, and a second member 53 that extends horizontally from an upper part of the first member 52. The sliding portion 72 is inserted into a through hole formed in the second member 53 and is a shaft 80 extending in the vertical direction, and a gripping portion 81 provided at the upper end of the shaft 80 for gripping the end portion of the hanging lower member 71, and a receiving portion 82 provided at the lower end of the shaft 80, and includes The elastic member 73 is provided between the lower surface of the second member 53 and the receiving portion 82. The conveying device according to any one of Configurations 1 to 3. (Configuration 5) When the tensile force is within the normal range, the elastic member 73 contracts from its natural length, and the light-shielding portion 74 is located above the optical path LP of the inspection light. When the tensile force changes from within the normal range to outside the normal range, the elastic member 73 expands, and the light-shielding portion 74 is displaced downward toward the optical path LP of the inspection light. The conveying device according to any one of Configurations 1 to 4. (Configuration 6) The detection device 63 is provided at the upper end portion of the first member 52. The light-shielding portion 74 is provided on each of the plurality of gripping portions 81. The conveying device according to any one of Configurations 1 to 5.

[0076] One or more of the requirements described in the above-described embodiments and the like may be omitted. Further, the requirements described in the above-described embodiments and the like can be combined as appropriate. Also, the execution order of each procedure shown in the present embodiment can be realized in an arbitrary order as long as the result of the previous procedure is not used in the subsequent procedure. Also, regarding the operations in the above-described embodiments, even if they are described for convenience using "first", "next", "subsequently", etc., it is not essential to perform them in this order.

Description of Reference Numerals

[0077] 30... Stacker crane, 50... Lift table, 60... Lifting device, 63... Detection device, 64... Hanging mechanism, 71... Hanging lower member, 73... Elastic member, 74... Light-shielding portion, 90... Light projecting portion, 91... Light receiving portion

Claims

1. A lifting part for supporting an article, A lifting device for lifting and lowering the lifting part in the vertical direction, comprising: The lifting device includes: A plurality of suspension mechanisms for supporting the lifting part so as to be movable up and down in the vertical direction, One detection device for detecting an abnormality in the suspension mechanism, comprising: The detection device includes: A light projecting part for projecting inspection light, A light receiving part for receiving the inspection light, Each of the suspension mechanisms includes: A suspension member for suspending the lifting part, An elastic member that expands and contracts according to the tensile force of the suspension member, A light shielding part that is displaced in the vertical direction according to the expansion and contraction of the elastic member, Each of the light shielding parts is out of 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 conveying device.

2. One end of each of the plurality of suspension members is connected to the lifting part, and an adjusting part for adjusting the weight balance is connected to the other end of each of the plurality of suspension members, The conveying device according to claim 1.

3. Each of the suspension mechanisms includes a sliding part that is slidable in the vertical direction with respect to the lifting part, One end of the suspension member is connected to the sliding part, 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, The positional relationship changes by the relative sliding movement of the sliding part and the lifting part due to the fluctuation of the tensile force, The conveying device according to claim 1.

4. The lifting part is, A placement part on which the article is placed, A first member extending upward from an end of the placement part, A second member extending horizontally from an upper part of the first member, and comprising: The slide part is Inserted into a through hole formed in the second member and a shaft extending in the vertical direction, A gripping part provided at an upper end of the shaft and gripping an end of the hanging lower member, A receiving part provided at a lower end of the shaft, and comprising: The elastic member is provided between a lower surface of the second member and the receiving part. The conveying device according to claim 3.

5. When the tensile force is within the normal range, the elastic member contracts from its natural length, and the light-shielding part is 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 expands, and the light-shielding part is displaced downward toward the optical path of the inspection light. The conveying device according to any one of claims 1 to 4.

6. The detection device is provided at an upper end part of the first member, The light-shielding part is provided on each of the plurality of gripping parts. The conveying device according to claim 4.

Images