Roller device

Abstract

To provide a roller device suitable for a conveying device provided with a connecting mechanism.SOLUTION: This roller device is provided with a first roller 51 arranged in a frame structure 20 and rotating around a first common shaft extending in the vertical direction, and a second roller 56 arranged in the frame structure 20 at an interval in the horizontal direction from the first roller 51 and rotating around a second common shaft extending in the vertical direction. The roller device further includes a third roller 53 that rotates about the first common axis independently of the first roller 51, and a fourth roller 57 that rotates about the second common axis independently of the second roller 56. The diameter of the first roller 51 is larger than the diameter of the third roller 53, and the diameter of the second roller 56 is larger than the diameter of the fourth roller 57.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a roller device that can be used in a conveying device or the like that has a connecting mechanism. [Background technology]

[0002] In production sites such as factories, caster-equipped platforms such as dollies and wagons are used to move transported objects such as workpieces. Automatically controlled vehicles (AGVs) are sometimes used to move the platforms to desired positions. The platforms are connected to the AGVs via a coupling mechanism. The coupling mechanism can couple the platforms to the AGVs or detach the platforms from the AGVs as needed.

[0003] Patent Document 1 describes an automated guided vehicle having a coupling mechanism using a coupling pin. The automated guided vehicle is configured to be able to enter under the loading platform. The coupling mechanism includes a coupling pin provided on the upper surface of the automated guided vehicle, a drive mechanism for moving the coupling pin in the vertical direction, and a pin receiving portion provided on the underside of the loading platform. The loading platform is coupled to the automated guided vehicle by raising the coupling pin with the drive mechanism and inserting the coupling pin into the pin receiving portion.

[0004] Patent Document 2 also describes an automated guided vehicle having a coupling part. The coupling part has a connecting rod provided on the underside of the platform and a clamping mechanism provided on the upper surface of the automated guided vehicle. When the automated guided vehicle is placed under the platform, the clamping mechanism grips the connecting rod, thereby coupling the platform to the automated guided vehicle.

[0005] Patent Document 3 describes an automated guided vehicle equipped with a guide section and a connecting mechanism. A first example of the connecting mechanism described in Patent Document 3 has a pair of guide sections provided on the upper surface of the automated guided vehicle, a connectable member provided on the underside of the platform, and a connecting pin that is horizontally movable. A pin receiving hole into which the connecting pin is inserted is formed in the connectable member. With the connectable member inserted between the guide sections, the platform is connected to the automated guided vehicle by inserting the connecting pin into the pin receiving hole. The second example of the coupling mechanism in Patent Document 3 has a pair of guide parts provided on the upper surface of the automated guided vehicle, a pair of connecting shafts provided on the underside of the platform, and a connecting member that can move horizontally. With the connecting shafts inserted between the guide parts, the connecting member is pressed against the connecting shafts, thereby coupling the platform to the automated guided vehicle. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-232078 [Patent Document 2] Japanese Patent Application Publication No. 2019-162953 [Patent Document 3] Japanese Patent Application Publication No. 2018-24415 Summary of the Invention [Problem to be solved by the invention]

[0007] These Patent Documents 1 to 3 do not disclose a roller device suitable for a conveying device or the like equipped with a connecting mechanism, and in particular, do not disclose a first roller that is arranged on a frame structure and rotates around a first axis extending in the vertical direction, a second roller that is arranged on the frame structure at a horizontal distance from the first roller and rotates around a second axis extending in the vertical direction, a third roller that is arranged on the frame structure and rotates independently of the first roller around an axis extending in the same direction as the first axis, or a fourth roller that is arranged on the frame structure and rotates independently of the second roller around an axis extending in the same direction as the second axis.

[0008] Furthermore, there was no disclosure that the first roller and the third roller are each mounted on a first common shaft and are rotatable independently of each other around the first common shaft, and that the second roller and the fourth roller are each mounted on a second common shaft and are rotatable independently of each other around the second common shaft, nor was there any disclosure that the diameter of the first roller is larger than the diameter of the third roller and that the diameter of the second roller is larger than the diameter of the fourth roller.

[0009] The present invention provides a roller device suitable for a conveying device or the like equipped with a connecting mechanism. [Means for solving the problem]

[0010] In one embodiment, the roller device comprises a first roller arranged on a frame structure and rotating about a first axis extending in the vertical direction; a second roller arranged on the frame structure at a horizontal distance from the first roller and rotating about a second axis extending in the vertical direction; a third roller arranged on the frame structure and rotating independently of the first roller about an axis extending in the same direction as the first axis; and a fourth roller arranged on the frame structure and rotating independently of the second roller about an axis extending in the same direction as the second axis.

[0011] In the roller device of this embodiment, the first roller and the third roller may each be mounted on a first common shaft and be rotatable independently of each other around the first common shaft, and the second roller and the fourth roller may each be mounted on a second common shaft and be rotatable independently of each other around the second common shaft.

[0012] The diameter of the first roller may be larger than the diameter of the third roller, and the diameter of the second roller may be larger than the diameter of the fourth roller.

[0013] Furthermore, the first roller and the third roller may each have a roller body made of a material having rubber elasticity, and the second roller and the fourth roller may each have a roller body made of a material having rubber elasticity. [Effects of the Invention]

[0014] According to the present invention, it is possible to provide a roller device that can be suitably used in a conveying device or the like that is equipped with a connecting mechanism. [Brief explanation of the drawings]

[0015] [Figure 1] FIG. 1 is a perspective view of a transport device according to a first embodiment. [Figure 2] 2 is a perspective view of the conveying device shown in FIG. 1 in a state where the automatic guided vehicle and the platform are separated from each other. [Figure 3] FIG. [Figure 4] FIG. 3 is a cross-sectional view taken along the axis of a first roller assembly of the conveying device. [Figure 5] FIG. [Figure 6] FIG. [Figure 7] FIG. 2 is a plan view showing a part of the automated guided vehicle and the platform of the transport device. [Figure 8] FIG. 10 is a plan view of the transport device in a state where the loading platform is connected by a locking member. [Figure 9] FIG. 10 is a plan view schematically showing a part of a transport device according to a second embodiment. [Figure 10] FIG. 10 is a side view schematically showing a part of the transport device shown in FIG. 9. DETAILED DESCRIPTION OF THE INVENTION

[0016] A transport device according to a first embodiment will be described below with reference to FIGS. FIG. 1 is a perspective view of a conveying device 10. The conveying device 10 includes an automated guided vehicle 11, a platform 12, and a connecting mechanism 13. The connecting mechanism 13 has the function of connecting the automated guided vehicle 11 and the platform 12. FIG. 2 shows a state in which the automated guided vehicle 11 has moved away from the platform 12. FIG. 3 is a front view showing a part of the conveying device 10.

[0017] The automatic guided vehicle 11 will be described in detail later, and the loading platform 12 will be described first. The loading platform 12 has a frame structure 20, casters 21, 22, 23, and 24, and a first roller assembly 31 and a second roller assembly 32 provided on the frame structure 20. These roller assemblies 31 and 32 form part of the connecting mechanism 13. A loading section 35 (shown in FIGS. 1 and 2) is formed on the upper part of the frame structure 20 for placing an object to be transported thereon.

[0018] The frame structure 20 includes a pair of lower frames 36, 37, a vertical frame 38 extending in the vertical direction, upper frames 40, 41, 42, and a reinforcing member 43. A space 45 is formed below the upper frames 40, 41, 42, allowing the automatic guided vehicle 11 to enter from the horizontal direction.

[0019] Casters 21 and 22 are provided at both ends of one lower frame 36. Casters 23 and 24 are also provided at both ends of the other lower frame 37. These casters 21, 22, 23, and 24 can each rotate around a vertical axis, and can change direction depending on the direction in which the loading platform 12 is moving.

[0020] The first roller assembly 31 and the second roller assembly 32 have a common structure. The first roller assembly 31 is provided near one end 41a in the longitudinal direction of the upper frame 41. The second roller assembly 32 is provided near the other end 41b in the longitudinal direction of the upper frame 41. A cross section of the first roller assembly 31 is shown in Figure 4.

[0021] 4, the first roller assembly 31 has a first common shaft 50 extending in the vertical direction, and a first roller 51 and a third roller 53 mounted on the first common shaft 50. The first common shaft 50 is fixed to the underside of the upper frame 41 by a screw portion 50a and extends below the upper frame 41.

[0022] The first roller 51 is attached to the first common shaft 50 via a bearing member 51a. The first roller 51 is rotatable about a first axis X1 (shown in FIGS. 4 and 5) extending in the vertical direction. The third roller 53 is attached to the first common shaft 50 via a bearing member 53a. The third roller 53 is rotatable about an axis X3 (shown in FIG. 5) extending in the same direction as the first axis X1.

[0023] The first roller 51 has a roller body 51b (shown in FIG. 4) made of a material having rubber elasticity, such as urethane elastomer. The third roller 53 also has a roller body 53b made of a material having rubber elasticity, such as urethane elastomer. The diameter D1 of the first roller 51 is larger than the diameter D2 of the third roller 53. The first roller 51 and the third roller 53 rotate independently of each other about the first common shaft 50.

[0024] 5, 7, and 8, the second roller assembly 32 has a second common shaft 55 extending in the vertical direction, and a second roller 56 and a fourth roller 57 mounted on the second common shaft 55. Like the first common shaft 50, the second common shaft 55 is fixed to the lower surface of the upper frame 41 by a screw portion and extends below the upper frame 41.

[0025] The second roller 56 is attached to the second common shaft 55 via a bearing member. The second roller 56 is rotatable about a second axis X2 (shown in FIG. 5) extending in the vertical direction. The fourth roller 57 is attached to the second common shaft 55 via a bearing member. The fourth roller 57 is rotatable about an axis X4 (shown in FIG. 5) extending in the same direction as the second axis X2.

[0026] The second roller 56 and the fourth roller 57 each have a roller body made of a material having rubber elasticity, such as urethane elastomer. The diameter of the second roller 56 is larger than the diameter of the fourth roller 57. The second roller 56 and the fourth roller 57 rotate independently of each other around a second common shaft 55.

[0027] As shown in Fig. 8, the first roller assembly 31 and the second roller assembly 32 are arranged along an imaginary straight line M1 extending horizontally when viewed from above. As shown in Fig. 5, the first common shaft 50 and the second common shaft 55 are arranged on the upper frame 41 at a predetermined horizontal distance S1.

[0028] Next, the automatic guided vehicle 11 will be described. 6 is a plan view of the automated guided vehicle 11. The automated guided vehicle 11 includes a vehicle body 61 having a traveling mechanism 60 (shown in FIG. 2), and a coupling unit 62 arranged on top of the vehicle body 61. The traveling mechanism 60 is covered by a cover member 63. The vehicle body 61 includes software and an electrical configuration for controlling automatic operation so that the vehicle travels along a preset travel path.

[0029] The traveling mechanism 60 is equipped with wheels for moving the transport vehicle body 61 in a first direction (indicated by arrow F1) and a second direction (indicated by arrow F2). The traveling mechanism 60 also has a steering mechanism for rotating the transport vehicle body 61 around a vertical axis Z1. The transport vehicle body 61 can rotate in a first rotation direction (indicated by arrow R1) and a second rotation direction (indicated by arrow R2).

[0030] The coupling unit 62 is provided on the top of the transport vehicle body 61 and forms part of the coupling mechanism 13. The coupling unit 62 has a base plate 70 extending in a substantially horizontal direction, a guide rail section 73 including a pair of rail members 71, 72 arranged on the base plate 70, a locking member 74 that moves in the horizontal direction, an actuator 75 (shown in Figures 3 and 5) for moving the locking member 74, and a detection section 77 having a plurality of sensors 76 that detect the platform 12. The base plate 70 is fixed to the top surface of the transport vehicle body 61 by a plurality of fixing members 79 such as bolts.

[0031] The pair of rail members 71, 72 are each made of, for example, a metal plate and are fixed to the substrate 70 by fixing members 80 (shown in FIGS. 6 to 8). The rail members 71, 72 have straight portions 71a, 72a that extend horizontally and parallel to each other. The straight portions 71a, 72a form part of the length of the rail members 71, 72, respectively.

[0032] A gap G1 (shown in FIG. 7) is formed between the straight portions 71a and 72a. The gap G1 is slightly larger (for example, by about 1 mm to several mm) than the diameters of the first roller 51 and the second roller 56. Therefore, the first roller 51 and the second roller 56 can each enter the gap G1.

[0033] A first expanding portion 73a is formed on one end side of the guide rail portion 73. A second expanding portion 73b is formed on the other end side of the guide rail portion 73. When the guide rail portion 73 is viewed from above, the gap between the first expanding portion 73a widens from the distance (G1) between the rail members 71 and 72 to an entrance width W1 as the distance from one end of the straight portions 71a and 72a increases. The entrance width W1 is set to be at least twice the diameter of each of the first roller 51 and the second roller 56 so that the first roller 51 and the second roller 56 can easily enter.

[0034] As the distance from the other ends of the straight portions 71a and 72a increases, the second expanding portion 73b widens from the distance (G1) between the rail members 71 and 72 to an entrance width W2. The entrance width W2 is set to be at least twice the diameter of each of the first roller 51 and the second roller 56 so that the first roller 51 and the second roller 56 can easily enter.

[0035] The detection unit 77, which includes multiple sensors 76, has the function of detecting at least one of the first roller assembly 31 and the second roller assembly 32 when the automatic guided vehicle 11 enters the space 45 of the loading platform 12.

[0036] As shown in FIGS. 6 to 8, a groove 85 is formed in the substrate 70. The groove 85 extends in a direction perpendicular to the straight portions 71a and 72a of the rail members 71 and 72. The locking member 74 can move horizontally along the groove 85 between a first position (standby position) shown in FIGS. 6 and 7 and a second position (locked position) shown in FIG. 8. The substrate 70 is provided with an actuator 75 (shown in FIGS. 3 and 5) for moving the locking member 74 between the first position and the second position. One example of the actuator 75 is a ball screw mechanism driven by a servo motor.

[0037] When viewed from above the automatic guided vehicle 11, the locking member 74 has an end 91 including an end face 90, one side face 92, the other side face 93, and a pair of tapered faces 94, 95. The end face 90 is the front side when the locking member 74 moves from the first position to the second position. The end face 90 extends in the same direction as the straight portions 71a, 72a of the rail members 71, 72. The one side face 92 and the other side face 93 of the locking member 74 are the rear sides when the locking member 74 moves from the first position to the second position. The one side face 92 and the other side face 93 extend in a direction parallel to the groove portion 85.

[0038] The distance L1 (shown in FIG. 8) between one side surface 92 and the other side surface 93 is sufficiently larger than the distance L2 between the third roller 53 and the fourth roller 57. The width L3 of the end surface 90 is sufficiently smaller than the distance L2 between the third roller 53 and the fourth roller 57. In other words, the relationship is L1 > L2 > L3. One tapered surface 94 is formed between the end surface 90 and one side surface 92. The other tapered surface 95 is formed between the end surface 90 and the other side surface 93.

[0039] The distance L4 (shown in FIG. 7) between the tapered surfaces 94, 95 decreases from the one side surface 92 and the other side surface 93 toward the end surface 90. When the locking member 74 is moved to the second position, one of the pair of tapered surfaces 94, 95 contacts the third roller 53, and the other tapered surface contacts the fourth roller 57. Because such tapered surfaces 94, 95 are formed on the locking member 74, the locking member 74 can enter between the third roller 53 and the fourth roller 57 even if the relative positions of the automatic guided vehicle 11 and the platform 12 are slightly misaligned.

[0040] The operation of the transport device 10 of this embodiment will be described below. As the automated guided vehicle 11 moves toward the stopped loading platform 12, the automated guided vehicle 11 enters the space 45 inside the loading platform 12. When the automated guided vehicle 11 enters the inside of the loading platform 12, the automated guided vehicle 11 moves forward toward the gap G1 of the guide rail portion 73. Depending on the direction of movement of the automated guided vehicle 11, the first roller 51 or the second roller 56 is guided by the first widening portion 73a or the second widening portion 73b of the guide rail portion 73, and the first roller 51 and the second roller 56 enter the gap G1 of the guide rail portion 73.

[0041] Gap G1 of guide rail portion 73 is larger than diameter D1 (shown in FIG. 4) of first roller 51 and diameter D1 of second roller 56. Therefore, when first roller 51 and second roller 56 enter gap G1, first roller 51 and second roller 56 rotate while contacting either rail member 71 or 72. This makes it possible to avoid dust generation caused by rubbing between first roller 51 and second roller 56 and guide rail portion 73.

[0042] 7 shows a state in which the automated guided vehicle 11 has moved to a predetermined coupling position relative to the platform 12. At this time, the locking member 74 is in the first position (standby position). When the automated guided vehicle 11 moves to the predetermined position relative to the platform 12, the roller assemblies 31 and 32 are detected by the sensor 76, and the automated guided vehicle 11 stops. At this time, the first roller 51 and the second roller 56 are positioned in the gap G1 of the guide rail portion 73.

[0043] 8 shows the state in which the locking member 74 has moved to the second position (locked position). The locking member 74 is moved from the first position to the second position by an actuator 75 (shown in FIGS. 3 and 5). If the relative positions of the automatic guided vehicle 11 and the platform 12 are misaligned in the longitudinal direction of the guide rail portion 73 when the locking member 74 moves to the second position, the third roller 53 or the fourth roller 57 will come into contact with one tapered surface 94 or the other tapered surface 95.

[0044] When the locking member 74 moves toward the second position and the third roller 53 and the fourth roller 57 come into contact with the tapered surfaces 94, 95, the third roller 53 and the fourth roller 57 rotate. This makes it possible to prevent particles from being generated (dust generation) when the locking member 74 moves to the second position.

[0045] The first roller 51 and the third roller 53 provided on the first common shaft 50 can rotate independently of each other. Therefore, even if the direction in which the first roller 51 rotates when it enters the guide rail portion 73 differs from the direction in which the third roller 53 rotates when the locking member 74 moves toward the second position, the rotation of the first roller 51 and the rotation of the third roller 53 do not interfere with each other. Therefore, the first roller 51 and the third roller 53 can rotate without any problems.

[0046] Furthermore, the second roller 56 and the fourth roller 57 provided on the second common shaft 55 can rotate independently of each other. Therefore, even if the direction in which the second roller 56 rotates when it enters the guide rail portion 73 differs from the direction in which the fourth roller 57 rotates when the locking member 74 moves toward the second position, the rotation of the second roller 56 and the rotation of the fourth roller 57 do not interfere with each other. Therefore, the second roller 56 and the fourth roller 57 can rotate without any problems.

[0047] 8, when the locking member 74 reaches the second position, the locking member 74 is sandwiched between the third roller 53 and the fourth roller 57. In this manner, the automatic guided vehicle 11 travels with the locking member 74 sandwiched between the third roller 53 and the fourth roller 57 and the first roller 51 and the second roller 56 positioned in the gap G1 of the guide rail portion 73.

[0048] For example, the automated guided vehicle 11 moves in the first direction F1 or the second direction F2 (shown in FIG. 1). The load applied to the coupling mechanism 13 during travel is prevented by the locking member 74 being sandwiched between the third roller 53 and the fourth roller 57, so that the automated guided vehicle 11 and the platform 12 can be reliably coupled to each other.

[0049] The first roller 51 and the second roller 56 are inserted into the gap G1 of the guide rail portion 73. Therefore, the guide rail portion 73 prevents the automatic guided vehicle 11 and the platform 12 from moving relative to each other in the width direction. Moreover, the coupling mechanism 13 can exhibit great strength against the load applied to the coupling mechanism 13 when the automatic guided vehicle 11 and the platform 12 rotate around the vertical axis Z1.

[0050] When the automated guided vehicle 11 and the platform 12 are coupled to each other, the automated guided vehicle 11 automatically travels along a predetermined travel path, thereby transporting an object on the platform 12 to a predetermined position. The automated guided vehicle 11 and the platform 12 may rotate around a vertical axis Z1 to change direction. When the automated guided vehicle 11 rotates around the vertical axis Z1, the casters 21, 22, 23, and 24 rotate. As a result, a large force is applied to the coupling mechanism 13.

[0051] With respect to such rotation around the vertical axis Z1, the first roller 51 and the second roller 56 are restrained by the guide rail portion 73, and the third roller 53 and the fourth roller 57 are fixed by the locking member 74. Therefore, the connecting mechanism 13 can exhibit great strength against the load when the automatic guided vehicle 11 and the platform 12 move in the forward / backward direction or rotate around the vertical axis Z1.

[0052] In the connecting mechanism 13 of this embodiment, the first roller 51 and the third roller 53 are attached to the first common shaft 50. The second roller 56 and the fourth roller 57 are attached to the second common shaft 55. In other words, even though there are four rollers 51, 53, 56, and 57, only two common shafts 50 and 55 need to be used. This has the advantage of reducing the number of parts and making it easier to secure space for attaching the common shafts 50 and 55.

[0053] Fig. 9 is a plan view schematically showing a part of a connecting mechanism 13A of a transport device 10A according to the second embodiment. Fig. 10 is a side view schematically showing a part of the connecting mechanism 13A. In the transport device 10A of the second embodiment, parts common to the transport device 10 of the first embodiment (Figs. 1 to 8) are designated by the same reference numerals as those in the transport device 10 of the first embodiment, and description thereof will be omitted.

[0054] The coupling mechanism 13A has a first roller 51 and a third roller 53 that form a first roller assembly 31, and a second roller 56 and a fourth roller 57 that form a second roller assembly 32. The first roller 51 and the third roller 53 are attached to shaft members 100, 100 that are independent of each other. The first roller 51 rotates about a first axis X1 that extends in the vertical direction. The third roller 53 rotates independently of the first roller 51 about a third axis X3 that is parallel to the first axis X1 and extends in the same direction. The diameter of the first roller 51 is larger than the diameter of the third roller 53.

[0055] The second roller 56 and the fourth roller 57 are also attached to shaft members 110, 111 that are independent of each other. The second roller 56 rotates about a second axis X2 that extends in the vertical direction. The fourth roller 57 rotates independently of the second roller 56 about a fourth axis X4 that is parallel to and extends in the same direction as the second axis X2. The diameter of the second roller 56 is larger than the diameter of the fourth roller 57.

[0056] The first roller 51 and the second roller 56 enter the gap G1 of the guide rail portion 73. When the locking member 74 moves from the first position to the second position, the locking member 74 is sandwiched between the third roller 53 and the fourth roller 57. In this way, the automatic guided vehicle and the platform can be reliably coupled together.

[0057] It goes without saying that when implementing the present invention, the specific structures of the automated guided vehicle and the platform, as well as the specific aspects of the first roller assembly and second roller assembly, guide rail portion, locking member, actuator, etc. that make up the connecting mechanism can be modified in various ways. [Explanation of symbols]

[0058] 10, 10A... conveying device, 11... automated guided vehicle, 12... platform, 13... coupling mechanism, 20... frame structure, 31... first roller assembly, 32... second roller assembly, 50... first common shaft, 51... first roller, 53... third roller, 55... second common shaft, 56... second roller, 57... fourth roller, 60... traveling mechanism, 61... guided vehicle body, 62... coupling unit, 70... base plate, 71, 72... rail Member, 71a, 72a...straight portion, 73...guide rail portion, 73a...first expanding portion, 73b...second expanding portion, 74...locking member, 75...actuator, 90...end surface, 91...end portion, 92, 93...side surface, 94, 95...tapered surface, 100, 101, 110, 111...shaft member, G1...gap, X1...first axis, X2...second axis, X3...third axis, X4...fourth axis, Z1...vertical axis.

Claims

1. a first roller disposed on the frame structure and rotating about a first axis extending in the vertical direction; a second roller disposed on the frame structure at a horizontal distance from the first roller and rotating about a second axis extending in the vertical direction; a third roller disposed on the frame structure and rotating independently of the first roller about an axis extending in the same direction as the first axis; a fourth roller disposed on the frame structure and rotating independently of the second roller about an axis extending in the same direction as the second axis; A roller device comprising:

2. 2. The roller device according to claim 1, the first roller and the third roller are respectively provided on a first common shaft and are rotatable independently of each other around the first common shaft; a roller device in which the second roller and the fourth roller are respectively provided on a second common shaft and are rotatable independently of each other about the second common shaft;

3. 3. The roller device according to claim 2, The diameter of the first roller is larger than the diameter of the third roller, and A roller device in which the diameter of the second roller is larger than the diameter of the fourth roller.

4. 4. The roller device according to claim 3, the first roller and the third roller each have a roller body made of a material having rubber elasticity, The roller device includes a roller body made of a material having rubber elasticity, and the second roller and the fourth roller each have a roller body made of a material having rubber elasticity.

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