Conveying device

Abstract

To simplify or miniaturize a lifting mechanism for conveying a pallet between a conveying path and a return path.SOLUTION: A conveying device (2) includes a conveying part (6) that conveys a pallet (4) along a conveying path (6W), a return part (8) that conveys the pallet along a return path (8W), a descending part that transfers the pallet from the conveying path to the return path, and an ascending part (12) that transfers the pallet from the return path to the conveying path. At least either the descending part or the ascending part includes a lifting mechanism (24). The lifting mechanism includes a lifting part (50) capable of loading a pallet, an interlocking rod (54) located below the lifting part, multiple rotating parts (52) that connect the lifting part and the interlocking rod, and a driving part (56) that rotates a part of the rotating parts. The lifting mechanism transmits the movement of one rotating part rotated by the driving part to another rotating part by the interlocking rod, and rotates the other rotating parts together with the rotating part rotated by the driving part, thereby moving the lifting part up and down.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a conveying device, particularly to a conveying device that conveys goods by conveying a pallet on which the goods are loaded.

Background Art

[0002] Patent Document 1 describes a descending path portion and an ascending path portion for conveying a carriage between a vertically positioned conveying path portion and a return path portion in a conveying device that conveys a carriage along a guide rail.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In Patent Document 1, in order to convey the carriage from the return path portion to the conveying path portion via the ascending path portion, the carriage is lifted along the ascending path portion by a front wheel ascending arm and a rear wheel ascending arm that rotate around a drive shaft while rotating the arms. In other words, in Patent Document 1, since it is necessary to drive a plurality of mechanisms for ascending the carriage, the mechanism becomes complicated or large-sized.

Means for Solving the Problems

[0005] To solve the above problems, a transport device according to one aspect of the present disclosure includes: a transport unit that transports pallets in the transport direction along a transport path; a return unit that transports the pallets in the opposite direction to the transport direction along a return path located below the transport path; a lowering unit that transfers the pallets from the transport path to the return path; and an upward unit that transfers the pallets from the return path to the transport path, wherein at least one of the lowering unit and the upward unit includes a lifting unit capable of loading the pallets, an interlocking rod located below the lifting unit, a shaft, and an arm that rotates around the shaft. The lifting mechanism comprises a plurality of rotating parts, each having a first connecting part that is rotatably connected to the lifting part at one end of the arm, and a second connecting part that is rotatably connected to the interlocking rod on the side of the arm opposite to the shaft from the first connecting part, and a drive unit that rotates some of the rotating parts around the shaft, wherein the lifting mechanism transmits the movement of the rotating parts rotated by the drive unit to the other rotating parts via the interlocking rod, causing the other rotating parts to rotate together with the rotating parts rotated by the drive unit around the shaft, thereby raising and lowering the lifting part. [Effects of the Invention]

[0006] Simplify or miniaturize the lifting mechanism that transfers pallets between the transport and return paths. [Brief explanation of the drawing]

[0007] [Figure 1] This document shows an enlarged perspective view of a part of the conveying device according to the present disclosure, and an enlarged side view of a part of the conveying mechanism. [Figure 2] These are schematic perspective views, schematic plan views, and schematic side views of a transport device according to an embodiment of the present disclosure. [Figure 3] These are schematic perspective views and schematic side views of a pallet according to the embodiments of this disclosure. [Figure 4] This diagram shows a schematic side view of a transport unit and a return unit according to an embodiment of the present disclosure, and an enlarged view of a portion of the schematic side view. [Figure 5]These are enlarged plan views and enlarged side views of a portion of the transport unit and return unit according to the embodiments of this disclosure. [Figure 6] This is a partial side view of the process involving the transport unit, the return unit, and the lifting mechanism in the transfer of a pallet between the transport unit or return unit and the lifting mechanism according to an embodiment of the present disclosure. [Modes for carrying out the invention]

[0008] [Embodiment] <Conveying equipment: Overview> This embodiment describes a conveying device that transports cargo by transporting pallets loaded with cargo along a fixed route. In particular, the conveying device according to this embodiment is a conveying device that loads a vehicle body, such as an automobile, onto a pallet and transports the vehicle body. The conveying device according to this embodiment will be described with reference to Figure 2.

[0009] Figure 2 shows a schematic perspective view 202, a schematic plan view 204, and a schematic side view 206 of the transport device 2 according to this embodiment. In Figure 2, the vehicle body X transported by the transport device 2 is also shown. Note that the schematic plan view 204 and the schematic side view 206 show enlarged views of the vicinity of the lowering section 10 and the raising section 12, which will be described later, and the schematic perspective view 202 shows a part of the transport device 2 that is shown as a whole, but is omitted.

[0010] The transport device 2 comprises a pallet 4, a transport unit 6, a return unit 8, a lowering unit 10, and a lifting unit 12. The transport device 2 transports the pallet 4 along a fixed path using the transport unit 6, the return unit 8, the lowering unit 10, and the lifting unit 12. The transport device 2 also transports the vehicle body X by transporting the pallet 4 loaded with the vehicle body X using the transport unit 6, in a manner described later.

[0011] <Conveying equipment: Pallet> Pallet 4 will be explained in more detail with reference to Figure 3. Figure 3 shows a schematic perspective view 302 of pallet 4, a schematic side view 304 of pallet 4U in an upright state (described later), and a schematic side view 306 of pallet 4D in a tipped-over state, respectively.

[0012] Pallet 4 comprises a frame 14, a step 16, and a jig 18. Pallet 4 may have, for example, multiple step 16 fitted into openings in the frame 14. For example, Pallet 4 may be configured such that, while holding the vehicle body X by a method described later, a worker or the like can transfer onto the step 16 and perform tasks such as assembling parts onto the transported vehicle body X.

[0013] Multiple jigs 18 are formed on the frame 14, for example, and are arranged to protrude from an opening formed in the footboard 16 towards the upper surface of the pallet 4. Each jig 18 has, for example, a jig arm 22 that is movable upright and has a contact portion 20 at its tip. As shown in schematic side view 304, when the jig arm 22 is upright (hereinafter referred to as the upright state), the pallet 4U can support the vehicle body X on the contact portion 20. As shown in schematic side view 306, when the jig arm 22 is folded down (hereinafter referred to as the folded state), the height of the pallet 4D is reduced compared to the pallet 4U.

[0014] The jig arm 22 may be rotatably restrained to the upper surface of the pallet 4, such as the upper surface of the frame 14. The raising and lowering of the jig arm 22 may be achieved, for example, by an operator manipulating the jig 18 to rotate the jig arm 22 relative to the upper surface of the pallet 4.

[0015] <Conveying device: Conveying section> Returning to the reference of FIG. 2, the transport unit 6 transports the pallet 4U in a standing state in the transport direction DT along a transport path 6W extending in the transport direction DT. The transport device 2 loads the vehicle body X onto the standing pallet 4U and transports the vehicle body X in the transport direction DT by transporting the pallet 4U in the transport direction DT by the transport unit 6. The transport unit 6 includes, for example, a plurality of transport units 6U arranged in the transport direction DT. The transport unit 6 transports the pallet 4U in the transport direction DT by repeating the transfer of the pallet 4U from one transport unit 6U to the transport unit 6U adjacent in the transport direction DT.

[0016] The vehicle body X transported by a loading device (not shown) is loaded onto the pallet 4U located at the starting end of the transport path 6W. Also, the vehicle body X is taken out from the pallet 4U located at the terminal end of the transport path 6W by a take-out device (not shown). By the method described later, a pallet 4U without the vehicle body X loaded is transported to the starting end of the transport path 6W. The transport device 2 may sequentially transport, for example, the pallet 4U located at the starting end of the transport path 6W on which the vehicle body X is loaded by the transport unit 6. By this method, the transport device 2 may simultaneously transport a plurality of vehicle bodies X by the transport unit 6. As described above, an operator may transfer onto the pallet 4U transported by the transport unit 6, and the operator may perform work such as assembling parts to the transported vehicle body X.

[0017] <Transport device: Return unit> The return unit 8 transports the pallet 4D in a lying state in the return direction DR along a return path 8W extending in the return direction DR, which is the direction opposite to the transport direction DT. The return path 8W is located below the transport path 6W and at least partially overlaps the transport path 6W in plan view. The transport device 2 transports the pallet 4D in the return direction DR by the return unit 8, thereby transporting the pallet 4D to the upstream side of the return path 8W. The return unit 8 includes, for example, a plurality of return units 8U arranged in the return direction DR. The return unit 8 transports the pallet 4D in the return direction DR by repeating the transfer of the pallet 4D from one return unit 8U to the return unit 8U adjacent in the return direction DR.

[0018] <Transfer device: lowering part, raising part> The lowering part 10 lowers the pallet 4 conveyed to the end of the conveying path 6W and transfers the pallet 4 from the end of the conveying path 6W to the start of the return path 8W. The raising part 12 raises the pallet 4 conveyed to the end of the return path 8W and transfers the pallet 4 from the end of the return path 8W to the start of the conveying path 6W. Thereby, the transfer device 2 circulates the pallet 4 by the conveying part 6, the return part 8, the lowering part 10, and the raising part 12.

[0019] The upright pallet 4U conveyed to the end of the conveying path 6W may be, for example, on the conveying unit 6U located on the end side of the conveying path 6W or on the lowering part 10, and may become the laid-down pallet 4D when the jig arm 22 is laid down by an operator or the like. Also, the pallet 4D conveyed to the end of the return path 8W may become the pallet 4U when the jig arm 22 is raised by an operator or the like, for example, on the return unit 8U located on the end side of the return path 8W or on the raising part 12. Thereby, the conveying part 6 always conveys the upright pallet 4U, and the return part 8 always conveys the laid-down pallet 4D.

[0020] The lowering part 10 includes a lifting mechanism 24 adjacent to the conveying unit 6U located on the end side of the conveying path 6W and the return unit 8U located on the start side of the return path 8W. Also, the raising part 12 includes a lifting mechanism 24 adjacent to the conveying unit 6U located on the start side of the conveying path 6W and the return unit 8U located on the end side of the return path 8W. The lowering part 10 and the raising part 12 may include the same configuration of the lifting mechanism 24.

[0021] <Transfer device: Details of each part> The conveying part 6, the return part 8, and the lifting mechanism 24 will be described in more detail with reference to FIG. 1. FIG. 1 is a diagram showing an enlarged perspective view 102 of a part of the transfer device 2, an enlarged side view 104 of a part of the lifting mechanism 24, and another enlarged side view 106 of a part of the lifting mechanism 24.

[0022] Enlarged perspective view 102 is a perspective view that shows in particular the lifting mechanism 24 provided in the rising section 12 of the transport device 2, and the transport unit 6U and return unit 8U adjacent to the lifting mechanism 24. Each of the transport section 6 and the return section 8 may be provided with multiple transport units 6U and return units 8U having the same configuration as the transport unit 6U and return unit 8U shown in enlarged perspective view 102. The lowering section 10 may also be provided with a lifting mechanism 24 having the same configuration as the lifting mechanism 24 shown in enlarged perspective view 102.

[0023] Enlarged side view 104 and enlarged side view 106 are side views of the lifting mechanism 24 viewed in the direction DA shown in enlarged perspective view 102, in other words, from one of the two rails 26 (described later) to the other. Enlarged side view 104 and enlarged side view 106 each show the lifting mechanism 24 in the raised state and the lowered state, respectively, as described later.

[0024] The transport unit 6U of the transport section 6 includes rails 26, rollers 28, and a friction drive unit 30. The rails 26 are arranged along the transport direction DT. The transport unit 6U has two rails 26 spaced apart in directions perpendicular to the transport direction DT and the vertical direction. Multiple rollers 28 are formed on each rail 26 along the transport direction DT. The rollers 28 are arranged on each rail 26 such that the rollers 28 on two rails 26 face each other.

[0025] The friction drive units 30 are positioned on each of the two rails 26. Each friction drive unit 30 has a drive roller 30R with a rotation axis in the vertical direction. The two drive rollers 30R are positioned such that the pallet 4 to be transported is located between them. In particular, the two drive rollers 30R are positioned to grip the pallet 4 from the sides and to rub against each other against the sides of the pallet 4.

[0026] The return unit 8U of the return section 8 includes rails 26, rollers 28, and a friction drive unit 30. The return unit 8U is located below the transport unit 6U and may have the same configuration except that the rotation direction of each drive roller 30R, which will be described later, is opposite. The transport unit 6U and the return unit 8U may be formed as a single unit by fixing their respective rails 26 to each other via connecting parts 32.

[0027] <Conveying equipment: Conveying unit and return unit: Overview> The transport unit 6U and the return unit 8U will be described in more detail with reference to Figures 4 and 5. Figure 4 shows a schematic side view 402 of the transport unit 6U and the return unit 8U shown in the enlarged perspective view 102, and an enlarged side view 404 which is an enlarged portion of the schematic side view 402. Figure 5 shows an enlarged plan view 502 and an enlarged side view 504 which are enlarged portions of the transport unit 6U and the return unit 8U shown in the enlarged perspective view 102.

[0028] In Figure 4, schematic side view 402 is a side view of the transport unit 6U and return unit 8U as seen in the transport direction DT. In Figure 4, enlarged side view 404 is an enlarged side view of the vicinity of one of the two rails 26 of the transport unit 6U and return unit 8U, as seen in schematic side view 402. Schematic side view 402 also shows the side views of the pallets 4U and pallet 4D that are transported by the transport unit 6U and return unit 8U.

[0029] In Figure 5, the enlarged plan view 502 is a plan view showing an enlarged view of the vicinity of the optical axis sensor 34 and the contact sensor 36, which will be described later, in the transport unit 6U and the return unit 8U. The enlarged side view 504 is a side view of the transport unit 6U and the return unit 8U as seen in the direction DB shown in the enlarged plan view 502, in other words, from one of the two rails 26 to the other. In particular, the enlarged side view 504 is a side view showing an enlarged view of the vicinity of the optical axis sensor 34 and the contact sensor 36, which will be described later, in the transport unit 6U and the return unit 8U.

[0030] <Conveying equipment: Conveying unit and return unit: Rollers> As shown in the schematic side view 402 of Figure 4, rollers 28 are formed on the rails 26 of the transport unit 6U and the return unit 8U, and are rotatably constrained to a rotating shaft 28S that extends in a direction perpendicular to the transport direction DT and the vertical direction. In both the transport unit 6U and the return unit 8U, the rollers 28 formed on the two rails 26 face each other as described above.

[0031] Therefore, as shown in the schematic side view 402, the transport unit 6U and the return unit 8U each support the pallet 4 on the rollers 28 of the two rails 26 by placing the pallet 4 on the rollers 28. In this state, the friction drive unit 30 of the transport unit 6U or the return unit 8U grips the pallet 4 from the left and right ends with the two drive rollers 30R and rotates the two drive rollers 30R around the axis of rotation. As a result, the friction drive unit 30 feeds out the pallet 4 gripped by the two drive rollers 30R. Here, each roller 28 rotates around the axis of rotation 28S due to friction with the pallet 4 supported by each roller 28. In this way, the rollers 28 can transport the pallet 4 they support along the transport path 6W or the return path 8W.

[0032] The transport unit 6U and the return unit 8U each control the feeding of the pallet 4 by the friction drive unit 30, thereby transporting the pallet 4 in the transport direction DT or the return direction DR. For this reason, the rails 26 and rollers 28 of the transport unit 6U and the return unit 8U each form a part of the transport path 6W and the return path 8W, respectively, through which the pallet 4 is transported.

[0033] As shown in the schematic side view 402, the transport unit 6U transports the upright pallet 4U, and the return unit 8U transports the tipped-down pallet 4D. This allows the transport device 2 to transport the pallet 4U loaded with the vehicle body X to the transport unit 6U, while simultaneously transporting the pallet 4D, which is shorter than the pallet 4U, to the return unit 8U.

[0034] With the above configuration, the transport device 2 can transport the vehicle body X more reliably while shortening the vertical distance between the transport path 6W and the return path 8W, thereby reducing the total height of the transport section 6 and the return section 8. By reducing the total height of the transport section 6 and the return section 8, the transport device 2 reduces the height of the footboard 16 of the pallet 4U transported by the transport section 6, thereby reducing the burden on workers and others to climb up and down the pallet 4U.

[0035] As shown in the enlarged side view 404, the rollers 28 of the transport unit 6U and the return unit 8U are barrel rollers that have a curved surface 28C on the contact surface with the pallet 4, where the diameter is larger at the central part than at the ends along the rotation axis 28S. Therefore, even if the orientation of the rotation axis 28S is slightly tilted with respect to the transport direction DT due to, for example, manufacturing tolerances or the gravity of the goods on the pallet 4, the rollers 28 can maintain contact with the pallet 4 and the curved surface 28C.

[0036] For example, suppose the roller 28 has a curved surface with a constant diameter on its contact surface with the pallet 4, regardless of its position along the rotation axis 28S. In this case, when the orientation of the rotation axis 28S is tilted with respect to the conveying direction DT, there is a high possibility that one end of the roller 28 along the rotation axis 28S will come into contact with the pallet 4, resulting in what is known as one-sided contact. In this case, the pressure on the part of the roller 28 that comes into contact with the pallet 4 will increase, which may lead to a shortened lifespan of the roller 28.

[0037] Because the roller 28 is the barrel roller described above, the transport unit 6U and the return unit 8U can increase the likelihood that the contact surface of the roller 28 with the pallet 4 will be a curved surface 28C. Therefore, the transport unit 6U and the return unit 8U can reduce the shortening of the roller 28's lifespan due to uneven contact between the roller 28 and the pallet 4.

[0038] Each roller 28 of the transport unit 6U and the return unit 8U is supported only from the rail 26 side of the rotating shaft 28S, and is supported by the rail 26. In other words, the roller 28 is supported on only one side of the rotating shaft 28S. Therefore, the transport unit 6U and the return unit 8U do not require any members to support the roller 28 from both sides of the rotating shaft 28S, thus simplifying the structure of the transport device 2.

[0039] For example, in a configuration where the rollers 28 are supported from both sides of the rotating shaft 28S, a configuration can be considered in which the rotating shaft 28S rotatably restrains both of the two rollers 28 formed on the two rails 26, respectively. In this case, the rotating shaft 28S and other components are formed on the side of the transport path 6W or return path 8W that is closer to the rollers 28. Therefore, in the above configuration, in order to avoid interference between the components supporting the rollers 28 and the pallet 4 transported by the transport unit 6U or return unit 8U, the vertical distance between the transport unit 6U and the return unit 8U needs to be increased. As a result, the above configuration leads to an increase in the height of the transport device 2.

[0040] In this embodiment, the roller 28 is not supported on the rail 26 opposite to the rail 26 on which the roller 28 is supported. In other words, the roller 28 is not supported from the side where the pallet 4 is transported. With this configuration, the transport device 2 according to this embodiment can shorten the vertical distance between the transport unit 6U and the return unit 8U while avoiding interference between the member supporting the roller 28 and the pallet 4 being transported. Therefore, the transport device 2 according to this embodiment reduces the increase in height and reduces the burden on workers, etc., to move up and down with respect to the pallet 4U being transported by the transport unit 6.

[0041] As described above, the roller 28 in this embodiment is supported on only one side of the rotating shaft 28S. Therefore, when heavy cargo is loaded onto the pallet 4 being transported, the rotating shaft 28S that restrains the roller 28 is likely to bend around the rail 26 due to the gravity of the cargo. Even in this case, since the roller 28 is the barrel roller described above, the transport unit 6U and the return unit 8U can reduce the shortening of the roller 28's lifespan due to uneven contact between the roller 28 and the pallet 4.

[0042] <Conveying equipment: Conveying unit and return unit: Sensor> Referring to Figure 5, each of the transport unit 6U and the return unit 8U has an optical axis sensor 34 and a contact sensor 36 as sensors for detecting the pallet 4. The optical axis sensor 34 and the contact sensor 36 are formed on sensor arms 26A formed on the other rail 26 side of each rail 26 and are arranged along the transport direction DT. The optical axis sensor 34 and the contact sensor 36 are formed below the top of the rollers 28 to reduce interference with the pallet 4 being transported.

[0043] The conveying device 2 can determine the position of the pallet 4 on the conveying path 6W or return path 8W from the position of the optical axis sensor 34 or contact sensor 36 in the conveying direction DT when the pallet 4 is detected. Therefore, the conveying device 2 can more appropriately control the conveying of the pallet 4 by the conveying unit 6 or the return unit 8.

[0044] Furthermore, the optical axis sensor 34 and contact sensor 36 of the transport unit 6U and the return unit 8U may each have the same configuration. Also, in a plan view of the transport unit 6U and the return unit 8U, the optical axis sensor 34 and contact sensor 36 of the transport unit 6U and the return unit 8U may be formed in overlapping positions.

[0045] <Conveying device: Conveying unit and return unit: Optical axis sensor> The optical axis sensor 34 includes an element support portion 38, a light-emitting element 40, and a light-receiving element 42. The element support portion 38 is fixed to the sensor arm 26A. The light-emitting element 40 is fixed to the element support portion 38 and emits light such as infrared light toward the other rail 26. The light-receiving element 42 is fixed to the element support portion 38 at a distance from the light-emitting element 40 and is formed to receive light from the light-emitting element 40.

[0046] The optical axis sensor 34 detects a palette 4 that blocks light from the light-emitting element 40 to the light-receiving element 42, based on whether or not the light-receiving element 42 detects light from the light-emitting element 40. The palette 4 may have a protrusion that passes between the light-emitting element 40 and the light-receiving element 42 as it passes above the optical axis sensor 34.

[0047] In particular, the element support section 38 has a light-emitting element support section 38A, a light-receiving element support section 38B, and a connecting section 38C. The light-emitting element support section 38A is fixed to the sensor arm 26A, and the light-emitting element 40 is fixed to it. The light-receiving element support section 38B is formed at a distance from the light-emitting element support section 38A and facing it, and the light-receiving element 42 is fixed to it. The connecting section 38C connects the light-emitting element support section 38A and the light-receiving element support section 38B. In particular, in order to reduce interference with the protrusions of the pallet 4 described above, the connecting section 38C is formed below the optical path from the light-emitting element 40 to the light-receiving element 42 at a position that overlaps with the transport direction DT.

[0048] Here, the connection portion 38C is located at a position different from the position where it overlaps with the optical path on the lower side in a plan view of the transport unit 6U and the return unit 8U. In particular, in a plan view of the transport unit 6U and the return unit 8U, the optical axis sensors 34 of each unit are formed at the same position. Furthermore, in a plan view of the transport unit 6U and the return unit 8U, each part of the transport portion 6 and the return portion 8 is located at a position different from the position where it overlaps with the optical path on the lower side in a plan view.

[0049] With the above configuration, the transport device 2 does not have any other components in a position that overlaps with the optical path of the optical axis sensor 34 below it in a plan view. Therefore, even if foreign matter such as dust accumulates on a component located below the optical path, the transport device 2 reduces the obstruction of the optical path by that foreign matter. Consequently, the transport device 2 improves the accuracy of pallet 4 detection by the optical axis sensor 34.

[0050] <Conveying device: Conveying unit and return unit: Contact sensor> The contact sensor 36 detects the pallet by contacting the pallet 4 passing above and detecting the contact. The contact sensor 36 has a contact portion 44, a contact portion shaft 46, and a shaft support portion 48. The contact portion 44 may be formed to protrude upward from the contact portion shaft 46, which will be described later.

[0051] The contact portion 44 is the part that contacts the pallet 4 as it passes above the contact sensor 36. The contact portion 44 may also contact the protruding portion of the pallet 4 as described above. The contact portion shaft 46 rotatably restrains the contact portion 44 about the extension direction of the contact portion shaft 46 as its axis. The contact portion 44 may be biased to protrude upward from the contact portion shaft 46. The shaft support portion 48 is fixed to the sensor arm 26A and rotatably restrains the contact portion shaft 46 about the axis.

[0052] As the contact portion 44 comes into contact with the pallet 4, it is pushed by the pallet 4 and rotates around the contact portion shaft 46. The contact sensor 36 detects the pallet 4 by detecting the rotation of the contact portion 44 around the contact portion shaft 46, for example, thereby detecting the contact between the contact portion 44 and the pallet 4.

[0053] In the transport unit 6U shown in Figure 5, the optical axis sensor 34 is located downstream of the contact sensor 36 in the transport direction DT. In the return unit 8U shown in Figure 5, the optical axis sensor 34 is located upstream of the contact sensor 36 in the return direction DR. Furthermore, since the transport unit 6U and return unit 8U shown in Figure 5 are the same transport unit 6U and return unit 8U shown in the enlarged perspective view 102, the transport unit 6U and return unit 8U are located downstream of the transport path 6W and upstream of the return path 8W, respectively.

[0054] Based on the above, in Figure 5, the optical axis sensor 34 is located closer to the end of the transport path 6W and closer to the beginning of the return path 8W than the contact sensor 36. Furthermore, in the transport unit 6U and the return unit 8U located upstream of the transport path 6W and downstream of the return path 8W, the optical axis sensor 34 is located closer to the beginning of the transport path 6W and closer to the end of the return path 8W than the contact sensor 36. In other words, the optical axis sensor 34 is located closer to the lifting mechanism 24 on the transport path 6W or the return path 8W than the contact sensor 36.

[0055] In the conveying device 2 according to this embodiment, the transfer of pallets 4 between the conveying unit 6 or the return unit 8 and the lifting mechanism 24 takes longer than the transfer of pallets 4 between conveying units 6U or between return units 8U. In particular, time is required for loading or unloading cargo onto the pallets 4 before and after the transfer of pallets 4 between the conveying unit 6 and the lifting mechanism 24. Furthermore, in order to efficiently transport the vehicle body X in the conveying device 2, it is conceivable to intermittently feed pallets 4 from the conveying unit 6 and the return unit 8 to the lifting mechanism 24, respectively.

[0056] Therefore, in order to circulate the pallets 4 more efficiently in the conveying device 2 according to this embodiment, the conveying device 2 may increase the conveying speed of the pallets 4 in the vicinity of the lifting mechanism 24 in the conveying path 6W and the return path 8W. In this case, the conveying device 2 may be able to detect the position of the pallets 4 more precisely at the start and end ends of the conveying path 6W and the return path 8W where the conveying speed of the pallets 4 is high.

[0057] Generally, the optical axis sensor 34 can detect the pallet 4 more precisely than the contact sensor 36. Therefore, by positioning the optical axis sensor 34 closer to the start or end of the transport path 6W or return path 8W than the contact sensor 36, the position of the pallet 4 can be detected more precisely at positions where the transport speed of the pallet 4 is high, and the transport of the pallet 4 can be controlled more appropriately.

[0058] Furthermore, contact sensors 36 are generally less expensive or have a simpler structure than optical axis sensors 34. Therefore, by equipping the transport device 2 with both optical axis sensors 34 and contact sensors 36, the transport unit 6 or return unit 8 can be configured more cheaply or simply than when only optical axis sensors 34 are equipped, while allowing for more appropriate control of the transport of pallet 4.

[0059] As mentioned above, the pallet 4 may have a protrusion on its underside that obstructs the optical path from the light-emitting element 40 of the optical axis sensor 34 to the light-receiving element 42, or that contacts the contact portion 44 of the contact sensor 36. In this case, while the pallet 4 is being transported by the transport unit 6 or the return unit 8, the protrusion of the pallet 4 may pass between two rollers 28 facing each other.

[0060] In this embodiment, as described above, each roller 28 is supported only from the rail 26 side of the rotating shaft 28S. As a result, the conveying device 2 does not have a member supporting the rollers 28 on the lower side of the pallet 4 being conveyed, thus reducing interference between the member and the protruding part of the pallet 4.

[0061] <Conveying device: Lifting mechanism> Returning to Figure 1, the lifting mechanism 24 comprises a lifting section 50, a rotating section 52, a connecting rod 54, and a drive section 56. In the enlarged side view 104 and enlarged side view 106 of Figure 1, only the lifting section 50, the rotating section 52, the connecting rod 54, and the drive section 56 of the lifting mechanism 24 are shown.

[0062] The lifting section 50 includes the aforementioned rails 26, rollers 28 formed on the rails 26, and friction drive units 30 formed on each rail 26. The rails 26, rollers 28, and friction drive units 30 of the lifting section 50 may have the same configuration as the rails 26, rollers 28, and friction drive units 30 of the transport unit 6U or return unit 8U. In particular, the rails 26 of the lifting section 50 are arranged along the extending direction of the rails 26 of the transport unit 6U or return unit 8U adjacent to the lifting mechanism 24. By placing pallets 4 on the rollers 28 supported on each of the two rails 26 of the lifting section 50 and supporting the pallets 4 on the rollers 28, pallets 4 can be loaded onto the lifting section 50.

[0063] The lifting mechanism 24 has a plurality of rotating parts 52. Each rotating part 52 has a shaft 58, an arm 60, a first connecting part 62, and a second connecting part 64. The shaft 58 extends in a direction perpendicular to the transport direction DT and the vertical direction. The arm 60 is constrained to be rotatable around the shaft 58. The first connecting part 62 is rotatably connected to the lifting part 50 at one end of the arm 60. The second connecting part 64 is rotatably connected to the interlocking rod 54, which will be described later, on the side of the arm 60 opposite to the shaft 58 from the first connecting part 62.

[0064] The lifting mechanism 24 has multiple interlocking rods 54. Each interlocking rod 54 is located below the lifting section 50, and the interlocking rods 54 are connected to each other via a second connecting section 64. Therefore, each of the rotating sections 52 is connected via multiple interlocking rods 54. Furthermore, the interlocking rods 54 that are connected to each other are fixed to each other.

[0065] The drive unit 56 drives some of the rotating parts 52, causing the arms 60 of the rotating parts 52 to rotate around the shaft 58. For example, the drive unit 56 rotates the arm 60 of one rotating part 52 around the shaft 58.

[0066] The lifting mechanism 24 transmits the movement of the arm 60 of the rotating part 52 driven by the drive unit 56 to the arms 60 of the other rotating parts 52 that are not driven by the drive unit 56, via a linkage rod 54 that connects to the multiple rotating parts 52. As a result, the lifting mechanism 24 rotates the arms 60 of the other rotating parts 52 together with the arms 60 of the rotating part 52 driven by the drive unit 56 around each shaft 58. In this way, the lifting mechanism 24 raises and lowers the lifting part 50 in the vertical direction by rotating the arms 60 of each rotating part 52 around each shaft 58.

[0067] For example, the drive unit 56 moves the lifting unit 50 upward so that the lifting mechanism 24 becomes a lifting mechanism 24U in an elevated state, where the lifting unit 50 is positioned above the shaft 58, as shown in the enlarged side view 104. Alternatively, the drive unit 56 moves the lifting unit 50 downward so that the lifting mechanism 24 becomes a lifting mechanism 24D in a descending state, where the lifting unit 50 is positioned below the shaft 58, as shown in the enlarged side view 106.

[0068] The arm 60 of the rotating part 52 is composed of a first arm 60A that extends along a first direction D1 between the shaft 58 and the first connecting part 62, and a second arm 60B that extends along a second direction D2 that intersects the first direction D1 between the shaft 58 and the second connecting part 64. In other words, when viewed in the direction of extension of the shaft 58, the arm 60 bends on the shaft 58 and is not located on the same straight line. The angle at which the first direction D1 and the second direction D2 intersect may be, for example, 90°.

[0069] Because the arm 60 of the rotating part 52 is composed of a first arm 60A and a second arm 60B, the lifting mechanism 24 can shorten the distance between the first connecting part 62 and the second connecting part 64 compared to the case where the arm 60 extends in a straight line when viewed in the extension direction of the shaft 58. As a result, the dimensions of the lifting mechanism 24 can be reduced.

[0070] Furthermore, since the interlocking rod 54 connects the rotating parts 52, the range of rotation of the rotating parts 52 is limited to the range in which the interlocking rod 54 and the shaft 58 do not interfere with each other. In particular, the range of rotation of the rotating parts 52 is limited to the range in which the interlocking rod 54 is located below the shaft 58. For this reason, when the arm 60 extends in a straight line in the direction of extension of the shaft 58, the lifting part 50 can only move up and down above the shaft 58.

[0071] In this embodiment, since the arm 60 is composed of a first arm 60A and a second arm 60B, the lifting mechanism 24 can move both the lifting section 50 and the interlocking rod 54 below the shaft 58, as shown in the enlarged side view 106. Therefore, the lifting mechanism 24 can further extend the lifting distance of the lifting section 50 while reducing interference between the interlocking rod 54 and the shaft 58.

[0072] In this embodiment, the rail 26 of the lifting section 50 has an elongated hole 66 formed therein, and the first connecting portion 62 of at least one rotating section 52 is connected to the lifting section 50 via the elongated hole 66. For example, the rail 26 of the lifting section 50 has two elongated holes 66 formed therein, and the first connecting portions 62 of two rotating sections of the rotating section 52 located on the end side in the extension direction of the rail 26 of the lifting section 50 are connected to the lifting section 50 via each elongated hole 66.

[0073] As a result, the position of the first connecting portion 62 of the rotating portion 52, which is connected to the lifting portion 50 via the elongated hole 66, is allowed to have a certain degree of error in the longitudinal direction of the elongated hole 66. Therefore, even if there is some error in the position or dimensions of the rotating portion 52 due to manufacturing errors, etc., the elongated hole 66 absorbs the displacement of the first connecting portion 62, thereby absorbing the above error. Consequently, the lifting mechanism 24 can be manufactured more easily, or the yield during manufacturing can be improved.

[0074] In particular, in this embodiment, the longitudinal direction of each elongated hole 66 substantially coincides with the longitudinal direction of the rail 26 of the lifting section 50, in other words, the horizontal direction. This allows the lifting mechanism 24 to tolerate manufacturing errors and to limit the vertical position of the first connecting section 62 of the rotating section 52. Therefore, the lifting mechanism 24 reduces the vertical displacement of the lifting section 50.

[0075] Furthermore, as described above, the lifting mechanism 24 is equipped with multiple interlocking rods 54. Therefore, the interlocking rods 54 that are connected to each other at the second connecting section 64 do not have to be in a straight line, and their extension directions may intersect. Consequently, even if there is some error in the position or dimensions of the rotating section 52 due to manufacturing tolerances, the lifting mechanism 24 can absorb the displacement of the second connecting section 64 by adjusting the angle of the extension directions of the interlocking rods 54 that are connected to each other. Thus, the lifting mechanism 24 can be manufactured more easily, or the yield during manufacturing can be improved.

[0076] <Pallet transfer using conveying equipment> The transfer of the pallet 4 between the transport section 6 and the return section 8 by the lifting mechanism 24 will be explained in detail with reference to Figure 6. Figure 6 is an enlarged side view of the transport section 6, the return section 8, and a part of the lifting mechanism 24 when the lifting mechanism 24 of the lifting section 12 moves the pallet 4 from the return section 8 to the transport section 6.

[0077] In particular, the side views of each process in Figure 6 are enlarged views of the adjacent transport unit 6U and return unit 8U and the lifting mechanism 24 in the direction DC shown in the enlarged perspective view 102, in other words, from one of the two rails 26 described later to the other. In the cross-sectional views of each process in Figure 6, the transported pallet 4 is shown with a dotted line, and the components further back from the pallet 4 toward the plane of the paper are shown with the pallet 4 transparent. Hereafter, when referring to Figure 6, the lifting mechanism 24 will be described without mentioning that it is the lifting mechanism 24 provided in the lifting section 12.

[0078] For example, as shown in the process side view 602 of Figure 6, suppose the return unit 8 has transported the pallet 4 to the return unit 8U adjacent to the lifting unit 12, in other words, to the end of the return path 8W. For example, the pallet 4 is in a tipped-over state, pallet 4D. At this point, the lifting mechanism 24 rotates the rotating unit 52 with the drive unit 56 to lower the lifting unit 50. In other words, at this point, the lifting mechanism 24 is in a lowered state, lifting mechanism 24D.

[0079] In the lowered state of the lifting mechanism 24D, the height of the upper part of the roller 28 of the lifting section 50 is approximately the same as the height of the upper part of the roller 28 of the adjacent return unit 8U. Therefore, the return unit 8U and the lifting section 50 can transport the pallet 4 from the return unit 8U to the lifting section 50 by sending out the pallet 4 using their respective friction drive units 30. As a result, as shown in the cross-sectional view 604 of the process in Figure 6, the transport device 2 moves the pallet 4 from the return section 8 toward the lifting mechanism 24D.

[0080] Here, due to manufacturing tolerances in the lifting mechanism 24D, or deviations in the angle at which the drive unit 56 rotates the rotating part 52, a discrepancy may occur in the vertical position of the lifting part 50 of the lifting mechanism 24D. In this case, a discrepancy may occur between the height of the top of the roller 28 of the lifting part 50 and the height of the top of the roller 28 of the adjacent return unit 8U.

[0081] For example, another method for transporting the pallet 4 by the return section 8 is to transport the pallet 4 by sliding it along a rail formed along the return path 8W. In this case, as a method for transferring the pallet 4 from the return section 8 to the lifting mechanism 24D, one method is to slide the pallet 4 from the rail of the return section 8 to the rail of the lifting section 50.

[0082] In this case, if there is a misalignment in the vertical position of the lifting section 50 of the lifting mechanism 24D, a misalignment will occur between the height of the rail of the return section 8 and the height of the rail of the lifting section 50. In particular, for example, if the rail of the lifting section 50 is higher than the rail of the return section 8, the side of the pallet 4 may come into contact with the rail of the lifting section 50, making it difficult to transport the pallet 4. In addition, the pallet 4 may vibrate strongly due to the collision between the pallet 4 and the rail of the lifting section 50.

[0083] In this embodiment, the transport device 2 transports the pallet 4 by having the rollers 28 support the pallet 4 in both the return unit 8U and the lifting mechanism 24D, while the friction drive unit 30 pushes the pallet 4 out. In this case, for example, even if the rollers 28 of the lifting section 50 are higher than the rollers 28 of the return unit 8U, the transport device 2 can continue transporting the pallet 4 by having the pallet 4 move over the rollers 28 of the lifting section 50.

[0084] Therefore, in this embodiment, even if there is a difference in height between the upper part of the roller 28 in the lifting mechanism 24D and the return unit 8U, the conveying device 2 avoids, for example, the pallet 4 coming into contact with the rail 26, thereby reducing the possibility of difficulty in conveying the pallet 4. Furthermore, with the above configuration, the conveying device 2 in this embodiment can reduce vibration of the pallet 4 when the pallet 4 is transferred from the return unit 8 to the lifting mechanism 24D.

[0085] Furthermore, during the transport of pallets 4 between transport units 6U and between return units 8U, a discrepancy in the height of the top of the rollers 28 may occur due to manufacturing tolerances of the transport units 6U or return units 8U. In this case as well, for the same reasons as described above, the transport device 2 can reduce the possibility of difficulty in transporting pallets 4 between transport units 6U or return units 8U, and can also reduce vibration of pallets 4.

[0086] Furthermore, in this embodiment, the lifting mechanism 24 rotates the arms 60 that support the lifting section 50 around each shaft 58 in order to raise and lower the lifting section 50. For this reason, the distance between the rail 26 in the lifting mechanism 24U when it is raised and the rail 26 in the lifting mechanism 24D when it is lowered may differ from the distance between the transport section 6 and the return section 8. In other words, the distance between the rail 26 of the lifting mechanism 24U when it is raised and the rail 26 of the transport section 6 may differ from the distance between the rail 26 of the lifting mechanism 24D when it is lowered and the rail 26 of the return section 8.

[0087] Another example of a transport device for transporting a vehicle body X is a device that transports the vehicle body X by loading it onto a trolley having wheels that rotate on rails 26. However, in such a device, if the distance between the rails 26 of the lifting mechanism 24 and the rails 26 of the transport section 6 or the return section 8 becomes long, the transport of the trolley may be hindered, such as the wheels falling off between the rails 26.

[0088] In this embodiment, the conveying device 2 conveys the pallet 4 by having the rollers 28 support the pallet 4 and then sending the pallet 4 out using the friction drive unit 30. Therefore, even if the distance between the rails 26 of the lifting mechanism 24 and the rails 26 of the conveying section 6 or the return section 8 changes slightly, only the distance between the rollers 28 to which the pallet 4 is passed changes, so the conveying device 2 can transfer the pallet 4 without any problems. Accordingly, the conveying device 2 can reduce the possibility of difficulty in transferring the pallet 4 from the return section 8 to the lifting mechanism 24D, and can also reduce vibration of the pallet 4.

[0089] As shown in the process side view 606 of Figure 6, the conveying device 2 completes the transfer of the pallet 4 from the return unit 8 to the lifting mechanism 24D by moving the pallet 4 from the roller 28 of the return unit 8U onto the roller 28 of the lifting unit 50. Next, the lifting mechanism 24D raises the pallet 4 by rotating the rotating unit 52 with the drive unit 56 and raising the lifting unit 50. As a result, the lifting mechanism 24D becomes the lifting mechanism 24U in the raised state, as shown in the process side view 608 of Figure 6.

[0090] In the raised position of the lifting mechanism 24U, the height of the top of the roller 28 of the lifting section 50 is approximately the same as the height of the top of the roller 28 of the adjacent transport unit 6U. Therefore, the transport unit 6U and the lifting section 50 can transport the pallet 4 from the lifting section 50 to the transport unit 6U by the feed of the pallet 4 by the friction drive units 30 of each. As a result, as shown in the cross-sectional view 610 of the process in Figure 6, the transport device 2 moves the pallet 4 from the lifting mechanism 24U toward the transport section 6.

[0091] As shown in the process side view 612 of Figure 6, the conveying device 2 moves the pallet 4 from the roller 28 of the lifting unit 50 onto the roller 28 of the conveying unit 6U, thereby completing the transfer of the pallet 4 from the lifting mechanism 24U to the conveying unit 6. With this, the transfer of the pallet 4 from the return unit 8 to the conveying unit 6 by the conveying device 2 and the lifting mechanism 24 is completed.

[0092] Furthermore, the transfer of the pallet 4 from the transport unit 6 to the return unit 8 by the lifting mechanism 24 of the lowering unit 10 is also achieved in the same manner as described above. For example, the transport device 2 performs the transfer of the pallet 4 from the transport unit 6 to the return unit 8 by moving the pallet 4 from the transport unit 6 to the lifting mechanism 24, lowering the pallet 4 by the lifting mechanism 24, and moving the pallet 4 from the lifting mechanism 24 to the return unit 8.

[0093] <Summary> The transport device 2 according to this embodiment is equipped with a lifting mechanism 24 in the lowering section 10 or raising section 12 that transfers pallets 4 between the transport section 6 and the return section 8. The lifting mechanism 24 raises and lowers the lifting section 50 by using a connecting rod 54 to rotate the arm 60 of the other rotating section 52 together with the arm 60 of the rotating section 52 driven by the drive section 56, thereby raising and lowering the pallets 4 loaded on the lifting section 50.

[0094] With the above configuration, the transport device 2 can employ a drive unit 56 for the lifting mechanism 24 that drives only some of the multiple rotating parts 52. In other words, the transport device 2 does not require a drive unit 56 for the lifting mechanism 24 that rotates all of the arms 60 of the rotating parts 52.

[0095] Therefore, the conveying device 2 can simplify or miniaturize the lifting mechanism 24 that transfers the pallet 4 between the transport path 6W and the return path 8W. Thus, the conveying device 2 can simplify or miniaturize the lowering section 10 or the raising section 12 equipped with the lifting mechanism 24. In particular, by miniaturizing the lifting mechanism 24 in the vertical direction, the conveying device 2 can reduce the vertical dimensions of the entire device. As a result, the conveying device 2 reduces the height of the footboard 16 of the pallet 4U transported by the conveying section 6, and reduces the burden on the worker to move up and down the pallet 4U. Furthermore, with the above configuration, the conveying device 2 can arrange each part to avoid overlapping with the movement path of the pallet 4 that the lifting mechanism 24 moves up and down, while allowing the lifting mechanism 24 to perform the raising and lowering of the lifting section 50 with a simple configuration.

[0096] In particular, when both the lowering section 10 and the raising section 12 are equipped with a lifting mechanism 24, the conveying device 2 can be simplified or miniaturized in both the lowering section 10 and the raising section 12, and the entire device can be further simplified or miniaturized. For example, by miniaturizing the lifting mechanisms 24 of both the lowering section 10 and the raising section 12 in the vertical direction, the conveying device 2 can be further reduced in the vertical dimensions of the entire device.

[0097] In addition, if both the lowering section 10 and the raising section 12 are equipped with a lifting mechanism 24, the conveying device 2 may have one of the lifting mechanisms 24 of the lowering section 10 and the raising section 12 have the same configuration as the other lifting mechanism 24, and may also be arranged in opposite directions. This allows the conveying device 2 to transfer pallets 4 between the conveying section 6 and the return section 8 by having the same configuration for the lifting mechanisms 24 of the lowering section 10 and the raising section 12, while only differing in the orientation of one of the lifting mechanisms 24. Therefore, with the above configuration, the conveying device 2 can construct the lowering section 10 and the raising section 12 more simply or inexpensively.

[0098] This disclosure is not limited to the embodiments described above, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the different technical means disclosed in each embodiment are also included in the technical scope of this disclosure. [Explanation of Symbols]

[0099] 2. Conveying device 4 pallets 6. Conveying section 6W transport path 8. Return Department 8W return route 10 Descending section 12. Ascending section 24 Lifting mechanism 28 Laura 34 Optical axis sensor 36 Contact Sensor 40 light-emitting elements 42 Photodetector 50 Lifting section 52 Rotating parts 54 Interlocking rod 56 Drive unit 58 shaft 60 Arm 60A First Arm 60B Second Arm 62 1st connection part 64 2nd connection part 66 long hole D1 1st direction D2 2nd direction DT transport direction DR Return Direction

Claims

1. A conveying unit that transports pallets in the transport direction along the transport path, A return section that transports the pallet in the opposite direction to the transport direction along a return path located below the transport path, A lowering section for transferring the pallet from the transport path to the return path, The system includes a lifting section that transfers the pallet from the return path to the transport path, At least one of the lowering portion and the raising portion is A lifting section capable of loading the aforementioned pallets, A connecting rod located below the aforementioned lifting section, A plurality of rotating parts, each having a shaft, an arm that rotates around the shaft, a first connecting part that rotatably connects to the lifting part at one end of the arm, and a second connecting part that rotatably connects to the interlocking rod on the side of the arm opposite to the shaft from the first connecting part, The lifting mechanism includes a drive unit that drives a portion of the aforementioned rotating part and rotates the arm of the said rotating part around the shaft, The aforementioned multiple rotating parts are connected to the same interlocking rod, The lifting mechanism transmits the rotation of the arm of the rotating part driven by the drive unit around the shaft to the rotation of the arm of another rotating part around the shaft, via the interlocking rod, causing the arm of the other rotating part to rotate together with the arm of the rotating part driven by the drive unit around each shaft and in the same direction as the rotation of the arm of the rotating part driven by the drive unit around the shaft, thereby raising and lowering the lifting unit, in a transport device.

2. The conveying device according to claim 1, wherein both the lowering section and the raising section are equipped with the lifting mechanism.

3. The arm is composed of a first arm extending in a first direction between the shaft and the first connecting portion, and a second arm extending in a second direction intersecting the first direction between the shaft and the second connecting portion. The conveying device according to claim 1 or 2, wherein, among the plurality of rotating parts, the angle at which the first direction and the second direction intersect remains constant regardless of the rotation of each of the arms of the plurality of rotating parts around the shaft.

4. The conveying device according to any one of claims 1 to 3, wherein at least one of the first connecting portions of the rotating portion is connected to the lifting portion through an elongated hole formed in the lifting portion.

5. The lifting mechanism comprises a plurality of interlocking rods, The conveying device according to any one of claims 1 to 4, wherein at least two of the interlocking rods are connected to each other via the second connecting portion.

6. The conveying device according to any one of claims 1 to 5, wherein at least one of the conveying unit, the return unit, the lowering unit, and the raising unit has a roller that supports the pallet and rotates around a rotation axis perpendicular to the conveying direction to convey the pallet.

7. The conveying device according to claim 6, wherein the roller is a barrel roller having a curved surface on its contact surface with the pallet, the diameter of which is larger at the central part than at the ends along the axis of rotation.

8. The conveying device according to claim 6 or 7, wherein the roller is supported on only one side of the rotating shaft.

9. The conveying device according to any one of claims 1 to 8, wherein at least one of the conveying unit and the return unit has a sensor for detecting the pallet.

10. The sensor comprises a light-emitting element that emits light and a light-receiving element that detects light from the light-emitting element, and includes an optical axis sensor that detects the palette that blocks the light from the light-emitting element to the light-receiving element. Each part of the transport section and the return section is located in a position different from the position where it overlaps with the optical path from the light-emitting element to the light-receiving element on the lower side in a plan view. The pallet has a protrusion that passes between the light-emitting element and the light-receiving element when it passes above the optical axis sensor. The transport device according to claim 9, wherein the optical axis sensor detects the pallet by detecting the protrusion that blocks light from the light-emitting element to the light-receiving element.

11. The sensor includes a contact sensor that detects the pallet by contact with the pallet being transported. The conveying device according to claim 10, wherein the optical axis sensor is located on the start or end side of the conveying path or the return path than the contact sensor.

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