Carts and automated guided vehicles

Abstract

To provide a dolly that can minimize variations in a position of an automatic conveyance vehicle configured to slide under a loading platform and that can prevent cargo shifting.SOLUTION: A dolly is configured to be conveyed by an automatic conveyance vehicle that slides under a loading platform. The dolly includes: a plurality of first guide frames disposed on a bottom surface of the loading platform and configured to guide a liftable substantially circular lifting table included in the automatic conveyance vehicle when the automatic conveyance vehicle slides under the loading platform; and a second guide frame disposed on the bottom surface of the loading platform and configured to guide the lifting table when the lifting table is lifted up. The plurality of first guide frames and the second guide frame are arranged along the substantially circular shape of the lifting table. Each of the plurality of first guide frames has an L-shape in cross-section. The second guide frame has a rectangular shape in cross-section.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] An embodiment of the present invention relates to a cart transported by an automated guided vehicle used at a construction site, and also to an automated guided system including the cart and the automated guided vehicle. [Background technology]

[0002] In recent years, technological development of automatic guided vehicles (AGVs) has progressed, and automatic guided vehicles are beginning to be used in a variety of situations. For example, if automatic guided vehicles are used in warehouses where products are stored, it becomes possible to automatically transport a wide variety of products. This improves work efficiency and reduces costs. One such automatic guided vehicle is known to be one that moves under a cart and lifts it up for transport (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2019-59460 Summary of the Invention [Problem to be solved by the invention]

[0004] At construction sites, the materials loaded onto the platform of a cart are large and heavy, so if the weight of the materials is unbalanced, the load may shift when the automated guided vehicle lifts the cart.

[0005] In view of the above problems, one embodiment of the present invention has an object to provide a cart that can suppress variation in the position of an automated guided vehicle that slips under a loading platform and prevent cargo from shifting. Another object of one embodiment of the present invention is to provide an automated guided vehicle system that includes the cart and the automated guided vehicle. [Means for solving the problem]

[0006] A trolley in one embodiment of the present invention is a trolley that is transported by an automatic guided vehicle that slides under a loading platform, and includes a plurality of first guide frames that are provided on the bottom of the loading platform and guide a lift table that is approximately circular and can be raised and lowered when the automatic guided vehicle slides under the loading platform, and a second guide frame that is provided on the bottom of the loading platform and guides the lift table when the lift table is raised, the plurality of first guide frames and second guide frames are arranged to follow the approximately circular shape of the lift table, and each of the plurality of first guide frames has an L-shaped cross section, and the second guide frame has a rectangular cross section.

[0007] The height of each of the plurality of first guide frames from the bottom surface of the loading platform may be greater than the height of the second guide frame from the bottom surface of the loading platform.

[0008] The second guide frame may be curved to fit the substantially circular shape of the lift table.

[0009] One of the plurality of first guide frames arranged on the opposite side to the second guide frame may be curved so as to follow the substantially circular shape of the lift table.

[0010] One of the plurality of first guide frames arranged on the opposite side of the second guide frame may be provided with a protrusion that fits into a groove provided on the side of the lift table. The cross-sectional area of ​​the protrusion of the protrusion may increase from bottom to top.

[0011] An automated guided vehicle system according to one embodiment of the present invention includes the above-described carriage and the above-described automated guided vehicle. [Effects of the Invention]

[0012] According to one embodiment of the present invention, the position of the automatic guided vehicle below the platform of the cart can be stabilized, and the load can be prevented from shifting. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a schematic diagram illustrating a configuration of an automatic transport system according to an embodiment of the present invention. [Figure 2] 1 is a schematic diagram illustrating a configuration of a carriage of an automatic transport system according to an embodiment of the present invention. [Figure 3] 1 is a schematic diagram illustrating a configuration of a carriage of an automatic transport system according to an embodiment of the present invention. [Figure 4] 1 is a schematic diagram illustrating a configuration of an automatic guided vehicle of an automatic guided vehicle system according to an embodiment of the present invention. [Figure 5] 10 is a schematic diagram illustrating the operation of an automatic guided vehicle slipping under the platform of a carriage in an automatic guided vehicle system according to an embodiment of the present invention. FIG. [Figure 6] 10 is a schematic diagram illustrating the operation of an automatic guided vehicle slipping under the platform of a carriage in an automatic guided vehicle system according to an embodiment of the present invention. FIG. [Figure 7] 10A and 10B are schematic diagrams illustrating the turning operation of the automatic guided vehicle below the platform of the carriage in the automatic guided vehicle system according to one embodiment of the present invention. [Figure 8] 1 is a schematic diagram illustrating prevention of cargo collapse in an automatic conveying system according to an embodiment of the present invention. FIG. [Figure 9] FIG. 10 is a schematic diagram showing the configuration of a carriage in a modified example of the automatic transport system according to an embodiment of the present invention. [Figure 10] 10 is a schematic diagram showing the configuration of an L-shaped guide frame and a lift table in a modified example of the automatic transport system according to one embodiment of the present invention. FIG. [Figure 11] 10A and 10B are schematic diagrams illustrating an engagement operation between an L-shaped guide frame and a lift table in a modified example of the automatic transport system according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0014] Hereinafter, each embodiment of the present invention will be described with reference to the drawings. Note that the embodiments are merely examples, and any modifications that a person skilled in the art could easily make while maintaining the gist of the invention are naturally included within the scope of the present invention. Furthermore, in order to clarify the explanation, the drawings may show the width, thickness, shape, etc. of each part more schematically than the actual embodiment. However, the shapes shown in the drawings are merely examples and do not limit the interpretation of the present invention.

[0015] In this specification, for convenience of explanation, the terms "upper", "above", "upper part", "lower", "belower", and "lower part" are used to merely explain the vertical relationship of each component. For example, when explaining the positional relationship of components of a structure (e.g., a cart or an automated guided vehicle), the normal use state of the structure is used as the basis, and the surface side on which the structure is installed (e.g., the floor side) may be referred to as "lower", "belower", or "lower part".

[0016] In this specification, the letters "first," "second," or "third" attached to each component are convenient labels used to distinguish each component, and have no other meaning unless otherwise specified.

[0017] In this specification and drawings, the same reference numeral is used to collectively represent multiple identical or similar components, and uppercase or lowercase letters may be added to distinguish between the multiple components. Furthermore, a hyphen and a natural number may be used to distinguish between multiple parts of a single component.

[0018] In this specification, the term "automated guided vehicle" refers to a vehicle capable of automatic travel that lifts a cart and transports the cart to a specified location as instructed.

[0019] In this specification, the term "cart" refers to a vehicle capable of carrying materials and the like on its loading platform.

[0020] In this specification, "automated driving" includes not only driving according to instructions based on a program, but also autonomous driving by a control device equipped in the automated guided vehicle. Autonomous driving includes not only driving of an automated guided vehicle along a predetermined route toward a destination, but also driving while following a target.

[0021] [1. Configuration of the automatic transport system 10] 1 is a schematic diagram showing the configuration of an automatic conveyance system 10 according to one embodiment of the present invention. Specifically, FIG. 1 is a side view of the automatic conveyance system 10.

[0022] 1, the automated guided vehicle system 10 includes a carriage 100 and an automated guided vehicle 200. The carriage 100 includes a platform 110, casters 120, an L-shaped guide frame 131, and an I-shaped guide frame 132. The automated guided vehicle 200 includes a main body 210, crawlers 220, a lift table 231, and a liftable portion 232.

[0023] In the automated guided vehicle system 10, the automated guided vehicle 200 slides under the loading platform 110 of the cart 100, and the L-shaped guide frame 131 and the I-shaped guide frame 132 of the cart 100 engage with the lift table 231 of the automated guided vehicle 200, thereby connecting the cart 100 and the automated guided vehicle 200. This allows the automated guided vehicle 200 to lift and transport the cart 100. Below, the configurations of the cart 100 and the automated guided vehicle 200 will be described in detail with reference to FIGS. 2 to 4.

[0024] [2. Configuration of the cart 100] 2 and 3 are schematic diagrams showing the configuration of a carriage 100 of an automatic transport system 10 according to one embodiment of the present invention. Specifically, Fig. 2(A) and Fig. 2(B) respectively show a side view and a bottom view of the carriage 100. Also, Fig. 3 shows a cross-sectional view of the carriage 100 taken along line A1-A2 shown in Fig. 2(B).

[0025] As shown in FIGS. 2(A) and 2(B), four casters 120, three L-shaped guide frames 131, and one I-shaped guide frame 132 are provided on the bottom surface of the loading platform 110 of the dolly 100. The loading platform 110 is rectangular in shape having long and short sides, and the four casters 120 are disposed at the four corners of the loading platform 110. The casters 120 include wheels, and the wheels may be fixed so that they move in one direction, or may be fixed so that they can rotate freely so that the direction of movement can be changed. Note that the dolly 100 is not limited to the above-described configuration. For example, the loading platform 110 of the dolly 100 may be substantially circular or polygonal.

[0026] As shown in FIG. 3, the L-shaped guide frame 131 is a member having an L-shaped cross section. That is, the L-shaped guide frame 131 is configured such that a first flat plate portion 131a extending in a direction substantially perpendicular to the bottom surface of the loading platform 110 and a second flat plate portion 131b extending from the first flat plate portion 131a in a direction substantially horizontal to the bottom surface of the loading platform 110 are orthogonal to each other, and has an L-shaped cross section. Note that the L-shaped guide frame 131 is bent so that the second flat plate portion 131b faces the center of the loading platform 110. The I-shaped guide frame 132 is a member having an I-shaped (rectangular) cross section. That is, the I-shaped guide frame 132 is composed only of a first flat plate portion 132a extending in a direction substantially perpendicular to the bottom surface of the loading platform 110, and has an I-shaped cross section.

[0027] The three L-shaped guide frames 131 and one I-shaped guide frame 132 are arranged so as to be positioned approximately on the circumference of a predetermined circle centered on the loading platform 110. In other words, the three L-shaped guide frames 131 and one I-shaped guide frame 132 are arranged at positions rotated 45 degrees around the center of the loading platform 110 as the center of symmetry. Therefore, one of the three L-shaped guide frames 131 is arranged to face the I-shaped guide frame 132, and the remaining two of the three L-shaped guide frames 131 are arranged to face each other. The I-shaped guide frame 132 is arranged on a long side of the loading platform 110. As will be described in detail later, the automated guided vehicle 200 can enter under the loading platform 110 from the long side on which the I-shaped guide frame 132 is arranged, of the two long sides on which the loading platform 110 is arranged. For ease of explanation, the area inside a circle inscribed in the first flat plate portions 131a of the three L-shaped guide frames 131 and one I-shaped guide frame 132 (first flat plate portion 132a) may be referred to as the "inside guide frame area." In the automated guided vehicle system 10, when the lifting table 231 of the automated guided vehicle 200 is positioned inside the guide frame, the automated guided vehicle 200 can lift and transport the cart 100 or can turn. Therefore, when the lifting table 231 of the automated guided vehicle 200 is positioned in the inside guide frame area, it may be said that the cart 100 and the automated guided vehicle 200 are engaged with each other.

[0028] 3, the height h2 of the I-shaped guide frame 132 from the bottom surface of the loading platform 110 (i.e., the height of the first flat plate portion 132a) is smaller than the height h1 of the L-shaped guide frame 131 from the bottom surface of the loading platform 110 (i.e., the height of the first flat plate portion 131a). Also, the height h2 of the I-shaped guide frame 132 from the bottom surface of the loading platform 110 is smaller than the distance d1 from the bottom surface of the loading platform 110 to the second flat plate portion 131b of the L-shaped guide frame 131.

[0029] Although detailed description will be given later, the L-shaped guide frame 131 can guide the lift table 231 that enters the area inside the guide frame. Furthermore, the L-shaped guide frame 131 and the I-shaped guide frame 132 can guide the lift table 231 when the automated guided vehicle 200 turns.

[0030] Although FIG. 2(B) shows three L-shaped guide frames 131, the number of L-shaped guide frames 131 is not particularly limited. The number of L-shaped guide frames 131 may be one, two, or four or more. When the number of L-shaped guide frames 131 is four or more, two L-shaped guide frames 131 are arranged at positions corresponding to the diameter of the guide frame inner region, and the remaining L-shaped guide frames 131 are arranged consecutively along a semicircle of the guide frame inner region. Furthermore, while FIG. 2(B) shows one I-shaped guide frame 132, the number of I-shaped guide frames 132 may be two or more. When there are two or more I-shaped guide frames 132, they are arranged consecutively along a semicircle of the guide frame inner region. Furthermore, the center of the guide frame inner region is not limited to the center of the loading platform 110. The center of the guide frame inner region may be, for example, the center of gravity of the dolly 100.

[0031] [3. Configuration of the automated guided vehicle 200] Fig. 4 is a schematic diagram showing the configuration of an automatic guided vehicle 200 of an automatic guided vehicle system 10 according to one embodiment of the present invention. Specifically, Fig. 4(A) is a perspective view of the automatic guided vehicle 200 with a lift table 231 in a lowered state, and Fig. 4(B) is a perspective view of the automatic guided vehicle 200 with a lift table 231 in a raised state.

[0032] As shown in Figures 4(A) and 4(B), a pair of crawlers 220 are installed on the side of the main body 210. The automated guided vehicle 200 moves by rotating the pair of crawlers 220. When the pair of crawlers 220 are rotated in the same direction, the automated guided vehicle 200 can move forward or backward. When the pair of crawlers 220 are rotated in opposite directions, the automated guided vehicle 200 can turn at that position.

[0033] A lift table 231 is installed on the main body 210 of the automated guided vehicle 200 (see FIG. 4(A)). The lift table 231 can be raised and lowered by a lift movable part 232 installed on the upper surface of the main body 210 (see FIG. 4(B)). The automated guided vehicle 200, which has slipped under the loading platform 110 of the cart 100, can raise the lift table 231 and lift the cart 100. Furthermore, in the automated guided vehicle system 10, when the automated guided vehicle 200 has lifted the cart 100, it can drive the pair of crawlers 220 and transport the cart 100.

[0034] The lifting table 231 has a circular shape. The size of the circular shape of the lifting table 231 is smaller than the size of the area inside the guide frame. The size of the circular shape of the lifting table 231 is larger than the size of a circle inscribed in the second flat plate portion 131b of the L-shaped guide frame 131. In the area inside the guide frame, the lifting table 231 comes into contact with the bottom surface of the loading platform 110 and can lift the cart 100.

[0035] 4. Operation of the automatic transport system 10 Next, the operation of the automatic guided vehicle system 10 will be described with reference to Figures 5 to 8. For the sake of convenience, Figures 5 and 7 only show part of the configuration of the carriage 100 and part of the configuration of the automatic guided vehicle 200.

[0036] 5 and 6 are schematic diagrams illustrating the operation of the automated guided vehicle 200 sliding under the carriage 100 (i.e., the engagement operation) in the automated guided vehicle system 10 according to one embodiment of the present invention. The automated guided vehicle 200 slides under the platform 110 from the long side of the platform 110 (see FIG. 5(A)). The distance between the two casters 120 is greater on the long side of the platform 110 than on the short side of the platform 110. Therefore, the automated guided vehicle 200 can slide under the platform 110 without colliding with the casters 120. In addition, an I-shaped guide frame 132 is disposed on the long side of the platform 110 into which the automated guided vehicle 200 slides. When the automated guided vehicle 200 slides under the platform 110, the height of the lift table 231 from the floor surface is smaller than the height from the floor surface to the I-shaped guide frame 132. Therefore, the automated guided vehicle 200 can slip under the platform 110 without colliding with the I-shaped guide frame 132 (see FIG. 5(B)).

[0037] As the automated guided vehicle 200 moves toward the center of the loading platform 110, the lifting table 231 of the automated guided vehicle 200 is guided by the two L-shaped guide frames 131 adjacent to the I-shaped guide frame 132 and comes into contact with the first flat plate portion 131a of the L-shaped guide frame 131 facing the I-shaped guide frame 132, causing the automated guided vehicle 200 to stop (see FIG. 6(A)). The height of the second flat plate portion 131b of the L-shaped guide frame 131 from the floor surface is smaller than the height of the lifting table 231 from the floor surface. Therefore, the automated guided vehicle 200 comes into contact with the first flat plate portion 131a of the L-shaped guide frame 131 without colliding with the second flat plate portion 131b of the L-shaped guide frame 131, and can stop (see FIG. 6(B)).

[0038] In this way, in the automatic guided vehicle system 10, the lift table 231 is guided by the L-shaped guide frame 131 while the automatic guided vehicle 200 moves under the loading platform 110 of the cart 100, and the cart 100 and the automatic guided vehicle 200 engage with each other. Therefore, the engagement position of the automatic guided vehicle 200 below the loading platform 110 of the cart 100 can be stabilized.

[0039] FIG. 7 is a schematic diagram illustrating the turning operation of the automated guided vehicle 200 below the platform 110 of the carriage 100 in the automated guided vehicle system 10 according to one embodiment of the present invention. When the automated guided vehicle 200 turns, the lift table 231 is raised higher than the position for the engagement operation. That is, the lift table 231 is raised so that the side surface of the lift table 231 faces not only the first flat plate portion 131a of the L-shaped guide frame 131 but also the I-shaped guide frame 132. This fixes the position of the lift table 231 within the guide frame. When the automated guided vehicle 200 turns in this state, the lift table 231 is guided by the three L-shaped guide frames 131 and the one I-shaped guide frame 132, so the position of the automated guided vehicle 200 does not shift. This stabilizes the turning operation of the automated guided vehicle 200.

[0040] 8 is a schematic diagram illustrating how the automated transport system 10 according to one embodiment of the present invention prevents loads from shifting. As shown in FIG. 8, even if the cart 100 lifted by the elevated lift table 231 loses balance, the lift table 231 is locked by at least one of the three L-shaped guide frames 131, so the loading platform 110 does not tilt significantly. As a result, materials loaded on the loading platform 110 will not fall, preventing the load from shifting.

[0041] As described above, in the automated guided vehicle system 10 according to one embodiment of the present invention, the L-shaped guide frame 131 arranged on the bottom surface of the platform 110 of the cart 100 engages the cart 100 with the automated guided vehicle 200 while guiding the lift table 231 of the automated guided vehicle 200, and the automated guided vehicle 200 can transport the cart 100. This makes it possible to stabilize the engagement position of the automated guided vehicle 200 below the platform 110 of the cart 100. Furthermore, since the lift table 231 is guided by the L-shaped guide frame 131 and the I-shaped guide frame 132 during the turning operation of the automated guided vehicle 200, the turning operation of the automated guided vehicle 200 can be stabilized. Furthermore, the L-shaped guide frame 131 suppresses tilting of the platform 110, thereby preventing the load from shifting.

[0042] Below, several modified examples of the automatic conveyance system 10 according to the above-described embodiment will be described. However, the automatic conveyance system 10 is not limited to the following modified examples. Furthermore, below, when the configuration of a modified example is the same as the configuration described above, the description of the configuration of the modified example may be omitted.

[0043] <Variation 1> 9 is a schematic diagram showing the configuration of a carriage 100A in a modified example of the automatic transport system 10 according to an embodiment of the present invention. As shown in FIG. 9(A), two L-shaped guide frames 131, one L-shaped guide frame 131A, and one I-shaped guide frame 132A are arranged on the bottom surface of the loading platform 110 of the carriage 100A. The L-shaped guide frame 131A is arranged to face the I-shaped guide frame 132A. Furthermore, the two L-shaped guide frames 131, one L-shaped guide frame 131A, and one I-shaped guide frame 132A are arranged at positions rotated 45 degrees around the center of the loading platform 110.

[0044] The shape of the I-shaped guide frame 132A is curved along the circumference of the guide frame inner area. Furthermore, as shown in FIG. 9(B), the L-shaped guide frame 131A has a curved surface of the first flat plate portion 131Aa that faces the guide frame inner area. That is, the L-shaped guide frame 131A is also curved along the circumference of the guide frame inner area. When the lift table 231 of the dolly 100A is positioned in the guide frame inner area, the contact area between the L-shaped guide frame 131A and the I-shaped guide frame 132 and the lift table 231 can be increased. Therefore, the engagement position of the automated guided vehicle 200 below the loading platform 110 of the dolly 100A can be further stabilized.

[0045] <Variation 2> Fig. 10 is a schematic diagram showing the configuration of an L-shaped guide frame 131B and a lifting table 231B in a modified example of the automatic transport system 10 according to an embodiment of the present invention. Fig. 11 is a schematic diagram illustrating the engagement operation between the L-shaped guide frame 131B and the lifting table 231B in a modified example of the automatic transport system 10 according to an embodiment of the present invention.

[0046] As shown in FIG. 10(A), the L-shaped guide frame 131B includes a first flat plate portion 131Ba, a second flat plate portion 131Bb, and a protrusion portion 131Bc. The protrusion portion 131Bc is provided on a portion of the surface of the first flat plate portion 131Ba on the second flat plate portion 131Bb side. For example, the protrusion portion 131Bc may be provided in an upper region of the surface of the first flat plate portion 131Ba (a region away from the second flat plate portion 131Bb). The protrusion portion 131Bc includes one or more protrusions, and the number of protrusions is not particularly limited. The cross-sectional shape of the protrusion is, for example, triangular, but is not limited to this. The cross-sectional area of ​​the protrusion increases from bottom to top (as it moves away from the second flat plate portion 131Bb).

[0047] As shown in FIG. 10(B), a groove portion 231Ba is provided on the side surface of the lift table 231B. The groove portion 231Ba includes one or more grooves. The number of grooves is preferably equal to or greater than the number of protrusions of the protrusion portion 131Bc. The shape of the groove corresponds to the cross-sectional shape of the protrusion, and is, for example, triangular in cross section. Furthermore, the cross-sectional area of ​​the groove is preferably equal to or slightly smaller than the maximum cross-sectional area of ​​the protrusion.

[0048] As shown in FIG. 11(A), when the automated guided vehicle 200 moves under the platform 110 of the dolly 100, the automated guided vehicle 200 advances with the groove 231Ba of the lift-up table 231B in front, and the groove 231Ba of the lift-up table 231B comes into contact with the first flat plate portion 131Ba of the L-shaped guide frame 131B in the guide frame inner area. In this state, when the lift-up table 231B is raised, the groove of the groove 231Ba fits into the protrusion of the protrusion 131Bc. That is, the protrusion of the protrusion 131Bc can function as a guide for the groove of the groove 231Ba. Therefore, the lift-up table 231B can be raised and the position of the lift-up table 231B can be fixed. Therefore, in this modification as well, the engagement position of the automated guided vehicle 200 below the platform 110 of the dolly 100 can be further stabilized.

[0049] When protrusion 131Bc of L-shaped guide frame 131B and groove 231Ba of lift table 231B fit together, automated guided vehicle 200 can turn while the position of lift table 231B is fixed by L-shaped guide frame 131B. This makes it possible to further stabilize the turning operation of automated guided vehicle 200.

[0050] The above-described embodiments of the present invention may be combined as appropriate as long as they are not mutually inconsistent. Furthermore, even if a person skilled in the art appropriately adds or deletes components or modifies the design, or adds or omits steps or modifies conditions based on the embodiments, such combinations are included within the scope of the present invention as long as they include the gist of the present invention.

[0051] Even if there are other effects and advantages different from those brought about by the above-mentioned embodiments, those that are clear from the description in this specification or that can be easily predicted by a person skilled in the art are naturally understood to be brought about by the present invention. [Explanation of symbols]

[0052] 10: Automatic conveying system, 100, 100A: Cart, 110: Cargo bed, 120: Caster, 131, 131A, 131B: L-shaped guide frame, 131a, 131Aa, 131Ba: first plate portion, 131b, 131Bb: second flat plate portion, 131Bc: Protrusion, 132, 132A: I-shaped guide frame, 132a: first flat plate portion, 200:Automated guided vehicles, 210: Main body, 220: Crawler, 231, 231B: Lift table, 231Ba: Groove, 232 Lifting and lowering part

Claims

1. A cart transported by an automatic guided vehicle that slides under the loading platform, a plurality of first guide frames provided on the bottom surface of the loading platform and guiding a substantially circular lift table that can be raised and lowered and that is provided on the automated guided vehicle when the automated guided vehicle moves under the loading platform toward the center of the loading platform; a second guide frame provided on the bottom surface of the loading platform and configured to guide the lift-up table when the lift-up table is raised; the plurality of first guide frames and the second guide frames are arranged along the substantially circular shape of the lift-up table, Each of the plurality of first guide frames has an L-shaped cross section, The second guide frame has a rectangular cross section.

2. The dolly according to claim 1 , wherein a height of the loading platform of each of the plurality of first guide frames from the bottom surface is greater than a height of the loading platform of the second guide frame from the bottom surface.

3. The carriage according to claim 1 or 2, wherein the second guide frame is curved so as to conform to the substantially circular shape of the lift table.

4. 4. The cart according to claim 1, wherein one of the plurality of first guide frames arranged on the opposite side of the second guide frame is curved to conform to the approximately circular shape of the lift table.

5. A cart as described in any one of claims 1 to 4, wherein one of the plurality of first guide frames arranged on the opposite side of the second guide frame is provided with a protrusion that fits into a groove provided on the side of the lifting table.

6. The bogie according to claim 5 , wherein the cross-sectional area of ​​the protrusion of the protrusion portion increases from the bottom to the top.

7. The bogie according to any one of claims 1 to 6; and the automatic guided vehicle.

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