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, and more 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 Document

Patent Document

[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 lifting arm and a rear wheel lifting arm that rotate around a drive shaft. It is necessary to rotate the arm. In other words, in Patent Document 1, since it is necessary to drive a plurality of mechanisms for lifting the carriage, the mechanism becomes complicated or large-sized.

Means for Solving the Problems

[0005] To solve the above problems, a conveying device according to an aspect of the present disclosure includes a conveying unit that conveys a pallet in a conveying direction along a conveying path, a return unit that conveys the pallet in a direction opposite to the conveying direction along a return path located below the conveying path, a lowering unit that transfers the pallet from the conveying path to the return path, and a lifting unit that transfers the pallet from the return path to the conveying path. At least one of the lowering unit and the lifting unit includes a lifting and lowering unit capable of loading the pallet, an interlocking rod located below the lifting and lowering unit, a shaft, an arm that rotates around the shaft, a first connecting portion that is rotatably connected to the lifting and lowering unit at one end side of the arm, and a second connecting portion that is rotatably connected to the interlocking rod on a side of the arm opposite to the first connecting portion with respect to the shaft. The conveying device further includes a plurality of rotating portions having the above components, and a driving unit that rotates some of the rotating portions around the shaft. The lifting mechanism transmits the movement of the rotating portion rotated by the driving unit by the interlocking rod to other rotating portions, rotates the other rotating portions around each shaft together with the rotating portion rotated by the driving unit, and raises and lowers the lifting and lowering unit.

Advantages of the Invention

[0006] Simplify or miniaturize the lifting mechanism for transferring between the conveying path and the return path of the pallet.

Brief Description of the Drawings

[0007]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Mode for Carrying Out the Invention

[0008] 〔Embodiment〕 <Transport device: Overview> In the present embodiment, a transport device that transports goods by transporting a pallet loaded with goods along a fixed route will be described. In particular, the transport device according to the present embodiment is a transport device that loads a vehicle body such as an automobile on a pallet and transports the vehicle body. The transport device according to the present embodiment will be described with reference to FIG. 2.

[0009] FIG. 2 is a diagram showing a schematic perspective view 202, a schematic plan view 204, and a schematic side view 206 of the transport device 2 according to the present embodiment. In FIG. 2, the vehicle body X transported by the transport device 2 is also shown. Note that, for the schematic plan view 204 and the schematic side view 206, the vicinity of each of the lowering part 10 and the raising part 12 described later is enlarged and shown, and a part of the transport device 2 shown as a whole in the schematic perspective view 202 is omitted and shown.

[0010] The transport device 2 includes a pallet 4, a transport section 6, a return section 8, a lowering part 10, and a raising part 12. The transport device 2 transports the pallet 4 along a fixed route by the transport section 6, the return section 8, the lowering part 10, and the raising part 12. Further, the transport device 2 transports the vehicle body X by transporting the pallet 4 loaded with the vehicle body X by the transport section 6 by the method described later.

[0011] <Transport device: Pallet> Regarding pallet 4, it will be described in more detail with reference to FIG. 3. FIG. 3 is a diagram showing a schematic perspective view 302 of pallet 4, a schematic side view 304 of pallet 4U in an upright state to be described later, and a schematic side view 306 of pallet 4D in a collapsed state, respectively.

[0012] Pallet 4 has a frame body 14, a tread plate 16, and a jig 18. Pallet 4 has, for example, a plurality of tread plates 16 fitted into the openings of the frame body 14. For example, pallet 4 may be configured such that an operator or the like can transfer onto the tread plate 16 while holding the vehicle body X by the method described later, and work such as assembling parts to the vehicle body X being transported becomes possible.

[0013] The jig 18 is formed in a plurality on the frame body 14, for example, and is arranged to protrude to the upper surface side of the pallet 4 from the openings formed in the tread plate 16. The jig 18 has, for example, a contact portion 20 at the tip and a jig arm 22 that can be raised and lowered. As shown in the schematic side view 304, in the case where the jig arm 22 is in an upright state (hereinafter referred to as the upright state), the pallet 4U can support the vehicle body X on the contact portion 20. As shown in the schematic side view 306, in the case where the jig arm 22 is in a collapsed state (hereinafter referred to as the collapsed state), the height of the pallet 4D is reduced compared to the pallet 4U.

[0014] The jig arm 22 may be rotatably constrained to the upper surface of the pallet 4, such as the upper surface of the frame body 14, for example. The raising and lowering of the jig arm 22 may be realized, for example, by an operator operating the jig 18 and rotating the jig arm 22 with respect to the upper surface of the pallet 4.

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

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

[0017] <Conveying device: Returning unit> The returning unit 8 conveys the pallet 4D in a fallen state in the returning direction DR along a returning path 8W extending in the returning direction DR, which is the direction opposite to the conveying direction DT. The returning path 8W is located below the conveying path 6W and at least partially overlaps the conveying path 6W in plan view. The conveying device 2 conveys the fallen pallet 4D in the returning direction DR by the returning unit 8 to convey the pallet 4D to the upstream side of the returning path 8W. The returning unit 8 includes, for example, a plurality of returning units 8U arranged in the returning direction DR. The returning unit 8 transports the pallet 4D in the returning direction DR by repeating the transfer of the pallet 4D from a certain returning unit 8U to the adjacent returning unit 8U in the returning direction DR.

[0018] <Conveyor device: lowering section, raising section> The lowering section 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 section 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 conveyor device 2 circulates the pallet 4 by the conveying section 6, the return section 8, the lowering section 10, and the raising section 12.

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

[0020] The lowering section 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. Further, the raising section 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 section 10 and the raising section 12 may include a lifting mechanism 24 having the same configuration.

[0021] <Conveyor device: Details of each part> The conveying section 6, the return section 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 conveyor 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] The enlarged perspective view 102 is a perspective view that particularly shows in an enlarged manner the elevating mechanism 24 provided in the elevating portion 12 of the conveying device 2, and the conveying unit 6U and the return unit 8U adjacent to the elevating mechanism 24. Each of the conveying portion 6 and the return portion 8 may include a plurality of conveying units 6U and return units 8U having the same configuration as the respective conveying unit 6U and return unit 8U shown in the enlarged perspective view 102. Further, the lowering portion 10 may include an elevating mechanism 24 having the same configuration as the elevating mechanism 24 shown in the enlarged perspective view 102.

[0023] The enlarged side views 104 and 106 are side views of the elevating mechanism 24 as viewed in the direction DA shown in the enlarged perspective view 102, in other words, in the direction from one of the two rails 26 described later to the other. Each of the enlarged side views 104 and 106 shows the elevating mechanism 24 in the respective ascending state and descending state described later.

[0024] The conveying unit 6U of the conveying portion 6 has a rail 26, a roller 28, and a friction drive unit 30. The rail 26 is arranged along the conveying direction DT. The conveying unit 6U has two rails 26 arranged at intervals in the direction orthogonal to the conveying direction DT and the vertical direction. A plurality of rollers 28 are formed on each of the rails 26 along the conveying direction DT. The rollers 28 are arranged on each rail 26 such that the rollers 28 of the two rails 26 face each other.

[0025] The friction drive unit 30 is arranged on each of the two rails 26. Each friction drive unit 30 has a drive roller 30R having a rotation axis in the vertical direction. The two drive rollers 30R are arranged such that the pallet 4 to be conveyed is positioned between them. In particular, the two drive rollers 30R sandwich the pallet 4 from the sides and are arranged to frictionally contact the side surfaces of the pallet 4 with each other.

[0026] The return unit 8U of the return section 8 includes a rail 26, a roller 28, and a friction drive unit 30. The return unit 8U may have the same configuration except that it is located below the transport unit 6U and the rotation directions of the respective drive rollers 30R described later are opposite. The transport unit 6U and the return unit 8U may be integrally formed by fixing the rails 26 of each other to each other via a connecting portion 32.

[0027] <Conveyor: Transport Unit and Return Unit: Overview> With further reference to FIGS. 4 and 5, the transport unit 6U and the return unit 8U will be described in more detail. FIG. 4 is a diagram showing 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 obtained by enlarging a part of the schematic side view 402. FIG. 5 is a diagram showing an enlarged plan view 502 and an enlarged side view 504 obtained by enlarging a part of the transport unit 6U and the return unit 8U shown in the enlarged perspective view 102.

[0028] In FIG. 4, the schematic side view 402 is a side view of the transport unit 6U and the return unit 8U as viewed in the transport direction DT. In FIG. 4, the enlarged side view 404 is a side view obtained by enlarging the vicinity of one of the two rails 26 of the transport unit 6U and the return unit 8U in the schematic side view 402. The schematic side view 402 also shows the sides of the pallets 4U and 4D transported by the transport unit 6U and the return unit 8U.

[0029] In FIG. 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 viewed in the direction DB shown in the enlarged plan view 502, in other words, in the direction 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] <Conveyor device: Conveyor unit and return unit: Roller> As shown in the schematic side view 402 of FIG. 4, on each rail 26 of the conveyor unit 6U and the return unit 8U, a roller 28 is formed that is rotatably constrained to a rotary shaft 28S extending in a direction orthogonal to the conveyance direction DT and the vertical direction. In each of the conveyor unit 6U and the return unit 8U, the rollers 28 formed on the two rails 26 face each other as described above.

[0031] For this reason, as shown in the schematic side view 402, each of the conveyor unit 6U and the return unit 8U supports the pallet 4 on the rollers 28 of each of the two rails 26, thereby supporting the pallet 4 on the rollers 28. In this state, the friction drive unit 30 of the conveyor unit 6U or the return unit 8U rotates the two drive rollers 30R around the rotary shaft while clamping the pallet 4 from the end sides in the left - right direction by the two drive rollers 30R. Thereby, the friction drive unit 30 sends out the pallet 4 clamped by the two drive rollers 30R. Here, due to the friction between each roller 28 and the pallet 4 it supports, each roller 28 rotates around the rotary shaft 28S. As described above, the roller 28 enables the pallet 4 it supports to be conveyed along the conveyance path 6W or the return path 8W.

[0032] Each of the conveyor unit 6U and the return unit 8U conveys the pallet 4 in the conveyance direction DT or the return direction DR by controlling the sending - out of the pallet 4 by the friction drive unit 30. For this reason, each of the rails 26 and the rollers 28 of the conveyor unit 6U and the return unit 8U forms a part of each of the conveyance path 6W and the return path 8W along which the pallet 4 is conveyed.

[0033] As shown in the schematic side view 402, the transport unit 6U transports the pallet 4U in the upright state, and the return unit 8U transports the pallet 4D in the laid-down state. Thereby, the transport device 2 can cause the transport unit 6U to transport the pallet 4U on which the vehicle body X is loaded, and cause the return unit 8U to transport the pallet 4D whose height is reduced compared to the pallet 4U.

[0034] With the above configuration, the transport device 2 can more reliably transport the vehicle body X while shortening the vertical distance between the transport path 6W and the return path 8W and reducing the total height of the transport unit 6 and the return unit 8. By reducing the total height of the transport unit 6 and the return unit 8, the transport device 2 reduces the height of the tread plate 16 of the pallet 4U transported by the transport unit 6 and reduces the burden of lifting and lowering for operators and the like with respect to the pallet 4U.

[0035] As shown in the enlarged side view 404, each roller 28 of the transport unit 6U and the return unit 8U is a barrel roller having a curved surface 28C with a larger diameter on the central portion side than on both end portion sides along the rotation axis 28S on the contact surface with the pallet 4. For this reason, for example, even if the direction of the rotation axis 28S is slightly inclined about the transport direction DT due to a manufacturing error or the gravity of the goods on the pallet 4 or the like, the roller 28 can maintain the state of being in contact with the pallet 4 and the curved surface 28C.

[0036] For example, assume that the roller 28 has a curved surface with an equal diameter on the contact surface with the pallet 4 regardless of the position along the rotation axis 28S. In this case, when the direction of the rotation axis 28S is inclined about the transport direction DT, there is a high possibility of so-called single contact where one of both ends along the rotation axis 28S of the roller 28 contacts the pallet 4. In this case, the pressure applied to the portion of the roller 28 in contact with the pallet 4 increases, which may lead to shortening of the life of the roller 28.

[0037] Since the roller 28 is the barrel roller described above, the conveyance unit 6U and the return unit 8U can increase the possibility that the contact surface between the roller 28 and the pallet 4 is the curved surface 28C. Therefore, the conveyance unit 6U and the return unit 8U can reduce the shortening of the life of the roller 28 associated with the contact between the roller 28 and the pallet 4.

[0038] Each roller 28 of the conveyance unit 6U and the return unit 8U is supported by the rail 26 only from the side of the rail 26 on the side of the rotation axis 28S. In other words, the roller 28 is supported only on one side of the rotation axis 28S. For this reason, the conveyance unit 6U and the return unit 8U do not require a member for supporting the roller 28 from both sides of the rotation axis 28S, so that the structure of the conveyance device 2 can be further simplified.

[0039] For example, as a configuration for supporting the roller 28 from both sides of the rotation axis 28S, a configuration in which the rotation axis 28S rotatably restrains both of the two rollers 28 formed on the two rails 26 can be considered. In this case, members such as the rotation axis 28S are formed on the side of the conveyance path 6W or the return path 8W rather than the roller 28. Therefore, in the case of the above configuration, in order to avoid interference between the member supporting the roller 28 and the pallet 4 conveyed by the conveyance unit 6U or the return unit 8U, it is necessary to increase the vertical distance between the conveyance unit 6U and the return unit 8U. This causes an increase in the height of the conveyance device 2.

[0040] In the present embodiment, the roller 28 is not supported on the side of the rail 26 opposite to the side where the roller 28 is supported. In other words, the roller 28 is not supported from the side where the pallet 4 is conveyed. With this configuration, the conveyance device 2 according to the present embodiment can shorten the vertical distance between the conveyance unit 6U and the return unit 8U while avoiding interference between the member supporting the roller 28 and the conveyed pallet 4. Therefore, the conveyance device 2 according to the present embodiment reduces an increase in height and reduces the burden of lifting and lowering for an operator or the like with respect to the pallet 4U conveyed by the conveyance unit 6.

[0041] The roller 28 according to this embodiment is supported only on one side of the rotation axis 28S as described above. Therefore, when a heavy load is placed on the pallet 4 being conveyed, the rotation axis 28S that restrains the roller 28 is likely to bend about the rail 26 due to the gravity of the load. Even in this case, since the roller 28 is the above-described barrel roller, the conveying unit 6U and the return unit 8U can reduce the shortening of the life of the roller 28 caused by the contact between the roller 28 and the pallet 4.

[0042] <Conveying device: Conveying unit and return unit: Sensor> Referring to FIG. 5, each of the conveying 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 a sensor arm 26A formed on the other rail 26 side of each rail 26 and are arranged along the conveying direction DT. The optical axis sensor 34 and the contact sensor 36 are formed below the upper part of the roller 28 in order to reduce interference with the pallet 4 being conveyed.

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

[0044] Note that each of the optical axis sensors 34 and the contact sensors 36 included in each of the conveying unit 6U and the return unit 8U may have the same configuration as each other. Also, in a plan view of the conveying unit 6U and the return unit 8U, each of the optical axis sensors 34 and the contact sensors 36 included in each of the conveying unit 6U and the return unit 8U may be formed at 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 side. 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 the light from the light emitting element 40.

[0046] The optical axis sensor 34 detects the palette 4 that blocks the light from the light emitting element 40 to the light receiving element 42 based on whether or not the light from the light emitting element 40 is detected by the light receiving element 42. The palette 4 may have a protruding portion that passes between the light emitting element 40 and the light receiving element 42 when passing above the optical axis sensor 34.

[0047] In particular, the element support portion 38 includes a light emitting element support portion 38A, a light receiving element support portion 38B, and a connecting portion 38C. The light emitting element support portion 38A is fixed to the sensor arm 26A and the light emitting element 40 is fixed thereto. The light receiving element support portion 38B is formed at a position facing the light emitting element support portion 38A with a distance therebetween, and the light receiving element 42 is fixed thereto. The connecting portion 38C connects the light emitting element support portion 38A and the light receiving element support portion 38B. In particular, the connecting portion 38C is formed below the optical path at a position where it overlaps with the optical path from the light emitting element 40 to the light receiving element 42 and the conveyance direction DT in order to reduce interference with the protruding portion of the palette 4 described above.

[0048] Here, the connecting portion 38C is at a position different from the position where it overlaps with the above-described optical path on the lower side in the plan view of the conveyance unit 6U and the return unit 8U. In particular, in the plan view of the conveyance unit 6U and the return unit 8U, the optical axis sensors 34 provided in the conveyance unit 6U and the return unit 8U are formed at the same position with respect to each other. Further, in the plan view of the conveyance unit 6U and the return unit 8U, each part of the conveyance portion 6 and the return portion 8 is at a position different from the position where it overlaps with the above-described optical path on the lower side.

[0049] With the above configuration, in a plan view, the conveyance device 2 does not have other members at a position overlapping with the optical path of the optical axis sensor 34 on the lower side. For this reason, even when foreign matter such as dust accumulates on the member located on the lower side of the optical path, the conveyance device 2 reduces the shielding of the optical path by the foreign matter. Therefore, the conveyance device 2 improves the accuracy of detecting the pallet 4 by the optical axis sensor 34.

[0050] <Conveyance device: Conveying unit and return unit: Contact sensor> The contact sensor 36 contacts the pallet 4 passing above and detects the contact to detect the pallet. The contact sensor 36 includes 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 described later.

[0051] The contact portion 44 is a portion that contacts the pallet 4 passing above the contact sensor 36. The contact portion 44 may contact the protruding portion of the pallet 4 described above. The contact portion shaft 46 rotatably restrains the contact portion 44 about the extending direction of the contact portion shaft 46. An urging force may be applied to the contact portion 44 so as 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 above axis.

[0052] When the contact portion 44 contacts the pallet 4, the contact portion 44 is pushed by the pallet 4 and rotates around the contact portion shaft 46. The contact sensor 36 detects the pallet 4 through the detection of the contact between the contact portion 44 and the pallet 4 by, for example, detecting the rotation of the contact portion 44 around the contact portion shaft 46.

[0053] Here, in the conveying unit 6U shown in FIG. 5, the optical axis sensor 34 is located downstream of the contact sensor 36 in the conveying direction DT. Further, in the return unit 8U shown in FIG. 5, the optical axis sensor 34 is located upstream of the contact sensor 36 in the return direction DR. Further, since the conveying unit 6U and the return unit 8U shown in FIG. 5 are the conveying unit 6U and the return unit 8U shown in the enlarged perspective view 102, each of the conveying unit 6U and the return unit 8U is located on the downstream side of the conveying path 6W and the upstream side of the return path 8W.

[0054] From the above, in FIG. 5, the optical axis sensor 34 is located on the end side of the conveying path 6W and the start side of the return path 8W with respect to the contact sensor 36. Note that in each of the conveying unit 6U and the return unit 8U located on the upstream side of the conveying path 6W and the downstream side of the return path 8W, the optical axis sensor 34 is located on the start side of the conveying path 6W and the end side of the return path 8W with respect to the contact sensor 36. In other words, the optical axis sensor 34 is located closer to the lifting mechanism 24 than the contact sensor 36 on the side of the conveying path 6W or the return path 8W.

[0055] In the conveying device 2 according to the present embodiment, the time required for the transfer of the pallet 4 between the conveying unit 6 or the return unit 8 and the lifting mechanism 24 is longer than the transfer of the pallet 4 between the conveying units 6U or the return units 8U. In particular, before and after the transfer of the pallet 4 between the conveying unit 6 and the lifting mechanism 24, time is required for loading or unloading the goods on the pallet 4. Further, in the conveying device 2, in order to efficiently convey the vehicle body X, it is conceivable to intermittently feed the pallet 4 from each of the conveying unit 6 and the return unit 8 to the lifting mechanism 24.

[0056] Therefore, in order to more efficiently circulate the pallet 4 in the conveying device 2 according to the present embodiment, the conveying device 2 may increase the conveying speed of the pallet 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 more precisely detect the position of the pallet 4 at the start end side and the end side of the conveying path 6W and the return path 8W where the conveying speed of the pallet 4 is high.

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

[0058] Also, generally, the contact sensor 36 is less expensive or has a simpler structure than the optical axis sensor 34. Therefore, by providing both the optical axis sensor 34 and the contact sensor 36, the transport device 2 can configure the transport unit 6 or the return unit 8 more inexpensively or simply compared to the case of providing only the optical axis sensor 34, while more appropriately controlling the transport of the pallet 4.

[0059] As described above, the pallet 4 may be provided with a protruding portion on the lower surface that blocks the optical path from the light emitting element 40 to the light receiving element 42 of the optical axis sensor 34 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 protruding portions of the pallet 4 may pass between the two rollers 28 facing each other.

[0060] In the present embodiment, as described above, each roller 28 is supported only from the side of the rail 26 of the rotation axis 28S. Thereby, since the transport device 2 does not have a member for supporting the roller 28 on the lower side of the pallet 4 to be transported, interference between the member and the protruding portion of the pallet 4 can be reduced.

[0061] <Transport device: Lifting mechanism> Referring back to FIG. 1, the lifting mechanism 24 includes a lifting portion 50, a rotating portion 52, an interlocking rod 54, and a driving portion 56. Here, in the enlarged side view 104 and the enlarged side view 106 of FIG. 1, only the above-described lifting portion 50, rotating portion 52, interlocking rod 54, and driving portion 56 of the lifting mechanism 24 are extracted and illustrated.

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

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

[0064] The elevating mechanism 24 has a plurality of interlocking rods 54. Each interlocking rod 54 is located below the elevating unit 50, and the interlocking rods 54 are connected to each other via the second connecting part 64. Therefore, each of the rotating parts 52 is connected via a plurality of interlocking rods 54. In addition, 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 and rotates the arm 60 of the rotating part 52 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 elevating mechanism 24 transmits the movement of the arm 60 of the rotating part 52 driven by the driving part 56 to the arm 60 of another rotating part 52 not driven by the driving part 56 through the linkage rod 54 connected to the plurality of rotating parts 52. Thereby, the elevating mechanism 24 rotates the arm 60 of the other rotating part 52 described above together with the arm 60 of the rotating part 52 driven by the driving part 56 around each shaft 58. As described above, the elevating mechanism 24 raises and lowers the elevating part 50 in the vertical direction by rotating the arm 60 of each rotating part 52 around each shaft 58.

[0067] For example, the driving part 56 moves the elevating part 50 upward, so that as shown in the enlarged side view 104, the elevating mechanism 24 is the elevating mechanism 24U in the ascending state where the elevating part 50 is located above the shaft 58. Further, the driving part 56 moves the elevating part 50 downward, so that as shown in the enlarged side view 106, the elevating mechanism 24 is the elevating mechanism 24D in the descending state where the elevating part 50 is located below the shaft 58.

[0068] The arm 60 of the rotating part 52 is composed of a first arm 60A extending along the first direction D1 between the shaft 58 and the first connecting part 62, and a second arm 60B extending along the second direction D2 intersecting the first direction D1 between the shaft 58 and the second connecting part 64. In other words, when viewed in the extending direction of the shaft 58, the arm 60 bends at 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] Since the arm 60 of the rotating part 52 is composed of the first arm 60A and the second arm 60B, the elevating mechanism 24 can shorten the distance between the first connecting part 62 and the second connecting part 64 as compared with the case where the arm 60 extends in a straight line when viewed in the extending direction of the shaft 58. Therefore, the elevating mechanism 24 can be reduced in size.

[0070] Note that since the interlocking rod 54 connects the rotating parts 52 to each other, the range within which the rotating parts 52 rotate is limited to a range where the interlocking rod 54 and the shaft 58 do not interfere. In particular, the range within which the rotating part 52 rotates is limited to a range where the interlocking rod 54 is located below the shaft 58. For this reason, when the arm 60 extends in a straight line in the extending direction 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 part 50 and the interlocking rod 54 below the shaft 58 as shown in the enlarged side view 106. For this reason, the lifting mechanism 24 can extend the lifting distance of the lifting part 50 while reducing the interference between the interlocking rod 54 and the shaft 58.

[0072] In this embodiment, a long hole 66 is formed in the rail 26 of the lifting part 50, and the first connecting part 62 of at least one rotating part 52 is connected to the lifting part 50 through the long hole 66. For example, two long holes 66 are formed in the rail 26 of the lifting part 50, and the first connecting parts 62 of the two rotating parts located on the end side in the extending direction of the rail 26 of the lifting part 50 among the rotating parts 52 are connected to the lifting part 50 through the respective long holes 66.

[0073] Thereby, with respect to the rotating part 52 connected to the lifting part 50 through the long hole 66, a certain degree of error in the longitudinal direction of the long hole 66 is allowed for the position of the first connecting part 62. For this reason, even when there is a slight error in the position or dimension of the rotating part 52 due to manufacturing errors or the like, the lifting mechanism 24 can absorb the above error by the long hole 66 absorbing the deviation of the position of the first connecting part 62. Therefore, the lifting mechanism 24 can be manufactured more easily, or the yield during manufacturing can be improved.

[0074] In particular, in the present embodiment, the longitudinal direction of each elongated hole 66 substantially coincides with the longitudinal direction of the rail 26 of the elevating portion 50, in other words, the horizontal direction. Thereby, the elevating mechanism 24 allows for manufacturing errors and can limit the position of the first connecting portion 62 of the rotating portion 52 in the vertical direction. Therefore, the elevating mechanism 24 reduces the deviation in the vertical position of the elevating portion 50.

[0075] Also, as described above, the elevating mechanism 24 includes a plurality of interlocking rods 54. For this reason, the interlocking rods 54 connected to each other at the second connecting portion 64 do not have to be in a straight line, and their extending directions may intersect each other. Therefore, even when there are some errors in the position or dimensions of the rotating portion 52 due to manufacturing errors or the like, the elevating mechanism 24 can absorb the deviation in the position of the second connecting portion 64 by adjusting the angle of the extending directions of the interlocking rods 54 connected to each other. Therefore, the elevating mechanism 24 can be manufactured more easily, or the yield during manufacturing can be improved.

[0076] <Delivery of the pallet by the conveying device> The delivery of the pallet 4 between the conveying portion 6 and the return portion 8 by the elevating mechanism 24 will be described in detail with reference to FIG. 6. FIG. 6 is an enlarged process side view of a part of the conveying portion 6, the return portion 8, and the elevating mechanism 24 when the elevating mechanism 24 provided in the ascending portion 12 moves the pallet 4 from the return portion 8 to the conveying portion 6.

[0077] In particular, each process side view in FIG. 6 is an enlarged view of the adjacent conveying unit 6U and return unit 8U and the elevating mechanism 24 in the direction DC shown in the enlarged perspective view 102, in other words, in the direction from one of the two rails 26 to the other described later. In each process cross-sectional view of FIG. 6, the conveyed pallet 4 is indicated by a dotted line, and the members behind the pallet 4 with respect to the paper surface are shown through the pallet 4. Hereinafter, when explaining with reference to FIG. 6, it is omitted to explain that the elevating mechanism 24 is the elevating mechanism 24 provided in the ascending portion 12.

[0078] For example, as shown in the process side view 602 of FIG. 6, it is assumed that the return unit 8 conveys the pallet 4 to the return unit 8U adjacent to the lifting unit 12, in other words, to the end side of the return path 8W. For example, the pallet 4 is a pallet 4D in a lying state. At this time, the lifting mechanism 24 drives the rotating part 52 to rotate by the driving part 56 and lowers the lifting part 50. In other words, at this time, the lifting mechanism 24 is a lifting mechanism 24D in a lowered state.

[0079] In the lowered lifting mechanism 24D, the height of the upper part of the roller 28 of the lifting part 50 is substantially 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 part 50 can convey the pallet 4 from the return unit 8U to the lifting part 50 by sending out the pallet 4 by the friction drive units 30 each of them has. Thereby, as shown in the process cross-sectional view 604 of FIG. 6, the conveying device 2 moves the pallet 4 from the return unit 8 toward the lifting mechanism 24D.

[0080] Here, due to manufacturing errors of the lifting mechanism 24D, or deviations in the angle by which the driving part 56 rotates the rotating part 52, etc., there may be a deviation in the vertical position of the lifting part 50 of the lifting mechanism 24D. In this case, there may be a deviation between the height of the upper part of the roller 28 of the lifting part 50 and the height of the upper part of the roller 28 of the adjacent return unit 8U.

[0081] For example, as another method of conveying the pallet 4 by the return unit 8, a method of conveying the pallet 4 by sliding it on a rail formed along the return path 8W can be considered. Also, in this case, as a method of delivering the pallet 4 from the return unit 8 to the lifting mechanism 24D, a method of sliding the pallet 4 from the rail of the return unit 8 to the rail of the lifting part 50 can be considered.

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

[0083] The transport device 2 according to the present embodiment transports the pallet 4 by causing the friction drive unit 30 to send out the pallet 4 while supporting the pallet 4 on the rollers 28 both in the return unit 8U and in the lifting mechanism 24D. In this case, for example, even when the roller 28 of the lifting part 50 is higher than the roller 28 of the return unit 8U, the transport device 2 can continue to transport the pallet 4 by causing the pallet 4 to cross over the roller 28 of the lifting part 50.

[0084] Therefore, the transport device 2 according to the present embodiment can avoid, for example, the pallet 4 coming into contact with the rail 26 and reduce the possibility of difficulty in transporting the pallet 4 even when there is a displacement in the height of the upper part of the roller 28 between the lifting mechanism 24D and the return unit 8U. Also, with the above-described configuration, the transport device 2 according to the present embodiment can reduce the vibration of the pallet 4 when transferring the pallet 4 from the return part 8 to the lifting mechanism 24D.

[0085] Note that even in the transport of the pallet 4 between the transport units 6U and in the transport of the pallet 4 between the return units 8U, a displacement may occur in the height of the upper part of the roller 28 due to manufacturing errors of the transport unit 6U or the return unit 8U or the like. Even in this case, for the same reason as described above, the transport device 2 can reduce the possibility of difficulty in transporting the pallet 4 between the transport units 6U or between the return units 8U and can also reduce the vibration of the pallet 4.

[0086] Furthermore, the elevating mechanism 24 according to the present embodiment rotates the arm 60 that supports the elevating unit 50 around each shaft 58 in order to raise and lower the elevating unit 50. For this reason, the distance between the rail 26 in the elevating mechanism 24U in the raised state and the rail 26 in the elevating mechanism 24D in the lowered state may be different from the distance between the conveyance unit 6 and the return unit 8. In other words, the distance between the rail 26 of the elevating mechanism 24U in the raised state and the rail 26 of the conveyance unit 6 and the distance between the rail 26 of the elevating mechanism 24D in the lowered state and the rail 26 of the return unit 8 may be different from each other.

[0087] As another example of the conveyance device that conveys the vehicle body X, for example, a device that loads and conveys the vehicle body X on a carriage having wheels that are rotationally driven on the rail 26 can be considered. However, in this device, when the distance between the rail 26 of the elevating mechanism 24 and the rail 26 of the conveyance unit 6 or the return unit 8 becomes long, there may be a problem in conveying the carriage, such as the wheels falling off between the rails 26.

[0088] The conveyance device 2 according to the present embodiment conveys the pallet 4 by causing the friction drive unit 30 to send out the pallet 4 while supporting the pallet 4 on the roller 28. For this reason, even when the distance between the rail 26 of the elevating mechanism 24 and the rail 26 of the conveyance unit 6 or the return unit 8 changes slightly, only the distance between the rollers 28 on which the pallet 4 is passed changes, so the conveyance device 2 can transfer the pallet 4 without trouble. Therefore, the conveyance device 2 can reduce the possibility that it becomes difficult to transfer the pallet 4 from the return unit 8 to the elevating mechanism 24D, and can also reduce the vibration of the pallet 4.

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

[0090] In the lifting mechanism 24U in the ascending state, the height of the upper part of the roller 28 of the lifting part 50 is substantially the same as the height of the upper part of the roller 28 of the adjacent conveying unit 6U. For this reason, the conveying unit 6U and the lifting part 50 can convey the pallet 4 from the lifting part 50 to the conveying unit 6U by sending out the pallet 4 by the friction drive units 30 each of them has. Thereby, as shown in the process cross-sectional view 610 of FIG. 6, the conveying device 2 moves the pallet 4 from the lifting mechanism 24U toward the conveying part 6.

[0091] As shown in the process side view 612 of FIG. 6, the conveying device 2 moves the pallet 4 from above the roller 28 of the lifting part 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 part 6. As described above, the transfer of the pallet 4 from the return part 8 to the conveying part 6 by the conveying device 2 and the lifting mechanism 24 is completed.

[0092] Note that the transfer of the pallet 4 from the conveying part 6 to the return part 8 by the lifting mechanism 24 provided in the lowering part 10 is also realized by the same method as the above-described method. For example, the conveying device 2 executes the transfer of the pallet 4 from the conveying part 6 to the return part 8 by moving the pallet 4 from the conveying part 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 part 8.

[0093] <Summary> The conveying device 2 according to the present embodiment includes a lifting mechanism 24 in the lowering part 10 or the ascending part 12 that performs the transfer of the pallet 4 between the conveying part 6 and the return part 8. The lifting mechanism 24 raises and lowers the lifting part 50 by rotating the arm 60 of the other rotating part 52 together with the arm 60 of the rotating part 52 driven by the driving part 56 by the interlocking rod 54, and raises and lowers the pallet 4 loaded on the lifting part 50.

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

[0095] Therefore, the transport device 2 can simplify or reduce the size of the lifting mechanism 24 that transfers between the transport path 6W and the return path 8W of the pallet 4. Thus, the transport device 2 can simplify or reduce the size of the lowering part 10 or the raising part 12 provided with the lifting mechanism 24. In particular, the transport device 2 can reduce the vertical dimension of the entire device by reducing the size of the lifting mechanism 24 in the vertical direction. Thereby, the transport device 2 reduces the height of the tread plate 16 of the pallet 4U transported by the transport unit 6 and reduces the burden of the operator's lifting and lowering with respect to the pallet 4U. Further, with the above configuration, the transport device 2 can cause the lifting part 50 to be lifted and lowered by the lifting mechanism 24 with a simple configuration while arranging each part avoiding the position overlapping the moving line of the pallet 4 lifted and lowered by the lifting mechanism 24.

[0096] In particular, when both the lowering part 10 and the raising part 12 are provided with the lifting mechanism 24, the transport device 2 can simplify or reduce the size of both the lowering part 10 and the raising part 12, and can further simplify or reduce the size of the entire device. For example, by reducing the size of the lifting mechanisms 24 of both the lowering part 10 and the raising part 12 in the vertical direction, the transport device 2 can further reduce the vertical dimension of the entire device.

[0097] In addition, when both the lowering part 10 and the raising part 12 are provided with the lifting mechanism 24, the transport device 2 may configure one of the lifting mechanisms 24 of the lowering part 10 and the raising part 12 to have the same configuration as the other lifting mechanism 24 and be arranged in the opposite direction. Thereby, the transport device 2 can realize the transfer of the pallet 4 between the transport part 6 and the return part 8 by making only the direction of one of the lifting mechanisms 24 different while making the configurations of the respective lifting mechanisms 24 of the lowering part 10 and the raising part 12 the same. Therefore, with the above configuration, the transport device 2 can configure the lowering part 10 and the raising part 12 more simply or inexpensively.

[0098] The present disclosure is not limited to the above-described embodiments, and various modifications are possible within the scope indicated in the claims. Embodiments obtained by appropriately combining different technical means disclosed in the embodiments are also included in the technical scope of the present disclosure.

Explanation of Reference Numerals

[0099] 2 Conveyor 4 Pallet 6 Conveyor Section 6W Conveyor Path 8 Return Section 8W Return Path 10 Lowering Section 12 Lifting Section 24 Lifting Mechanism 28 Roller 34 Optical Axis Sensor 36 Contact Sensor 40 Light Emitting Element 42 Light Receiving Element 50 Lifting and Lowering Section 52 Rotating Section 54 Linking Rod 56 Driving Section 58 Shaft 60 Arm 60A First Arm 60B Second Arm 62 First Connecting Portion 64 Second Connecting Portion 66 Long Hole D1 First Direction D2 Second Direction DT Conveying Direction DR Return Direction

Claims

1. A conveying unit that conveys a pallet in a conveying direction along a conveying path, A return unit that conveys the pallet in a direction opposite to the conveying direction along a return path located below the conveying path, A lowering unit that transfers the pallet from the conveying path to the return path, A lifting unit that transfers the pallet from the return path to the conveying path, and is provided with At least one of the lowering unit and the lifting unit is A lifting and lowering unit capable of loading the pallet, An interlocking rod located below the lifting and lowering unit, A shaft, an arm that rotates around the shaft, a first connecting portion that is rotatably connected to the lifting and lowering unit on one end side of the arm, and a second connecting portion that is rotatably connected to the interlocking rod on a side of the arm opposite to the first connecting portion with respect to the shaft, and has a plurality of rotating portions, A lifting mechanism having a driving unit that drives some of the rotating portions and rotates the arm of the rotating portion around the shaft. The lifting mechanism transmits the movement of the arm of the rotating portion driven by the driving unit to the arm of the other rotating portion through the interlocking rod, and rotates the arm of the other rotating portion around each shaft together with the arm of the rotating portion driven by the driving unit, and raises and lowers the lifting and lowering unit, a conveying device.

2. The conveying device according to claim 1, wherein both the lowering unit and the lifting unit are provided with the lifting mechanism.

3. The conveying device according to claim 1 or 2, wherein the arm is composed of a first arm that extends along a first direction between the shaft and the first connecting portion, and a second arm that extends along a second direction intersecting the first direction between the shaft and the second connecting portion.

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

5. The elevating mechanism includes a plurality of the 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 portion, the returning portion, the lowering portion, and the raising portion supports the pallet and has rollers that rotate around a rotation axis orthogonal 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 with a larger diameter on the central portion side than on both end portion sides along the rotation axis as a contact surface with the pallet.

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

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

10. The sensor includes a light emitting element that emits light and a light receiving element that detects light from the light emitting element, and has an optical axis sensor that detects the pallet that blocks the light from the light emitting element to the light receiving element, The conveying device according to claim 9, wherein each of the conveying portion and the returning portion is located at a position different from a position overlapping with an optical path from the light emitting element to the light receiving element in a plan view on the lower side.

11. The sensor has a contact sensor that detects the pallet by contact with the conveyed pallet, The conveying device according to claim 10, wherein the optical axis sensor is located closer to a start end side or a terminal end side of the conveying path or the returning path than the contact sensor.

Images