Transport system

Abstract

Provided is a transport system capable of increasing the processing amount of an entire system. A transport system (1), in which a plurality of sliders (5) circulate through a circulation path (6) including an outward path (2) and a return path (3), comprises a shift shaft (7) that moves three shift modules (7a, 7b, 7c) to be switched between a normal transport position and a position at which a workpiece is fed to a workpiece-processing device. At the normal transport position, first combination shift modules (7a, 7b) which are two shift modules selected from the three shift modules (7a, 7b, 7c) are linked to an outward path module (2a) and a return path module (3a). At the workpiece feed position, second combination shift modules (7b, 7c) which are two shift modules selected from the three shift modules (7a, 7b, 7c) are linked to the outward path module (2a) and the return path module (3a).

Description

Transport System

[0001] The present invention relates to a conveyance system in which a plurality of sliders circulate along a circulation path including an outward path and a return path.

[0002] A conveyance system has been developed in which multiple sliders circulate along a circulation path including an outbound path and a return path (see Patent Document 1). The outbound path is equipped with an outbound path module. The return path is equipped with a return path module. Multiple work processing devices are arranged along the outbound path to perform processing on the workpiece. When the slider moves to the position of the work processing device, the work processing device processes the workpiece mounted on the slider. For example, when the slider moves to the position of work processing device A, work processing device A performs machining processing on the workpiece mounted on the slider. Next, when the slider moves to the position of work processing device B, work processing device B performs screw tightening or the like on the workpiece mounted on the slider. Thereafter, in a similar manner, work processing device C applies adhesive to the workpiece, and work processing device D inspects the workpiece. When the slider moves to the end of the outbound path, the workpiece is discharged from the conveyance system. The slider returns along the return path to the start of the outbound path, loads the workpiece again, and circulates.

[0003] There are two types of slider circulation methods: the oval method and the circulation axis method (also called the traverser method). With the oval method, a semicircular module is connected to the ends of the forward and return paths, and the slider moves along the semicircular module while reversing its position. With the circulation axis method, a linear circulation axis is installed at the ends of the forward and return paths, and the circulation axis receives the slider from the forward path, moves it in the axial direction of the circulation axis, and hands it over to the return path. With the circulation axis method, the slider may be circulated horizontally or vertically.

[0004] Japanese Patent Application Laid-Open No. 2021-178721

[0005] However, in conventional conveying systems, if it takes a long time for a certain work processing device (e.g., work processing device A) to process a work, that work processing device (e.g., work processing device A) becomes a bottleneck, and there is a problem that the processing volume of the entire system cannot be increased.

[0006] In a conventional conveying system, if a shift axis is placed in front of the work processing device, and when the slider reaches the position of the work processing device, the shift axis can insert the slider into the work processing device, that is, the shift axis can move the outgoing module on which the slider is mounted and switch it from the normal conveying position to the work input position for the work processing device, so that the slider can wait in front of the work processing device, thereby shortening the downtime of the work processing device and therefore increasing the throughput of the entire system.

[0007] However, when the shift axis is used to switch the forward module from the normal transport position to the workpiece insertion position, the forward path is interrupted and the slider cannot be circulated quickly, which reduces the throughput of the entire system.

[0008] The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a transport system that can increase the throughput of the entire system.

[0009] In order to solve the above problem, a first aspect of the present invention is a conveying system in which a plurality of sliders circulate along a circulation path including an outbound path equipped with an outbound module and a return path equipped with a return module, the conveying system being equipped with a shift axis that moves at least three shift modules to switch between at least a normal conveying position and a work input position for a work processing device, and at the normal conveying position, first combination shift modules selected from the at least three shift modules are connected to the outbound module and the return module, and at the work input position, second combination shift modules selected from the at least three shift modules are connected to the outbound module and the return module.

[0010] A second aspect of the present invention is a conveying system in which a plurality of sliders circulate along a circulation path including an outward path with an outward path module and a return path with a return path module, the conveying system comprising a shift axis that moves at least the outward path shift module and the return path shift module to switch between at least a normal conveying position and a shortcut position, wherein at the normal conveying position, the outward path shift module and the return path shift module are connected to the outward path module and the return path module, and at the shortcut position, the outward path shift module equipped with a slider and the return path module are connected, and the slider shortcuts the circulation path.

[0011] According to the first aspect of the present invention, the slider can pass through the forward and backward paths regardless of the normal transport position and workpiece input position of the shift module on which the slider is mounted. Therefore, the slider can be circulated quickly, and the throughput of the entire system can be increased.

[0012] According to the second aspect of the present invention, for example, when processing of only workpiece processing device A is required, the slider can be moved to the position of workpiece processing device A and then returned to the start end of the forward path without moving to the positions of workpiece processing devices B and C. This makes it possible to increase the throughput of the entire system.

[0013] Fig. 2 is a plan view of a conveying system according to a first embodiment of the present invention. Fig. 3 is a plan view of a shift axis according to this embodiment (Fig. 2(a) is the normal conveying position, Fig. 2(b) is the workpiece insertion position, Fig. 2(c) is the normal conveying position). Fig. 4 is a plan view of a shift axis according to this embodiment (shortcut position). Fig. 5 is a perspective view of a forward module according to this embodiment. Fig. 6 is a perspective view of a slider according to this embodiment. Fig. 7 is a plan view of a conveying system according to a second embodiment of the present invention. Fig. 8 is a plan view of a shift axis of a conveying system according to a second embodiment of the present invention (Fig. 7(a) is the normal conveying position, Fig. 7(b) is the shortcut position).

[0014] Hereinafter, a transport system according to an embodiment of the present invention will be described with reference to the accompanying drawings. However, the transport system of the present invention can be embodied in various forms and is not limited to the embodiments described in this specification. The present embodiment is provided with the intention that those skilled in the art will be able to fully understand the invention by fully disclosing the specification. (First Embodiment)

[0015] 1 shows a plan view of a conveyance system 1 according to a first embodiment of the present invention. Reference numeral 2 denotes an outgoing path, reference numeral 3 denotes a returning path, and reference numerals 8 and 9 denote circulation axes provided at the ends of the outgoing path 2 and the returning path 3. The outgoing path 2, the returning path 3, and the circulation axes 8 and 9 constitute a circulation path 6. A plurality of sliders 5 circulate on the circulation path 6. Workpieces W are mounted on the sliders 5.

[0016] The outgoing path 2 is linear and includes multiple interconnected outgoing path modules 2a. The outgoing path 2 moves the slider 5 from a starting point P1 to the right in the drawing. Work processing devices A, B, and C, for example, are arranged along the outgoing path 2 to process the workpiece W (machining, screwing, adhesive application, inspection, etc.).

[0017] A shift shaft 7 is arranged in front of the work processing devices A, B, and C. When the slider 5 reaches the position of the work processing devices A, B, and C, the shift shaft 7 moves the three shift modules 7a, 7b, and 7c mounted thereon toward the work processing devices A, B, and C, and loads the workpiece W on the shift module 7a into the work processing devices A, B, and C (see work processing device C). The work processing devices A, B, and C perform machining or the like on the loaded workpiece W. The workpiece W may be supplied from the slider 5 to the work processing devices A, B, and C by a supply device (not shown), or the work processing devices A, B, and C may directly process the workpiece W on the slider 5.

[0018] After the workpiece W has been processed by the workpiece processing devices A, B, and C, the shift module 7a on which the slider 5 is mounted is returned to the outgoing path 2 by the shift shaft 7. The outgoing path 2 then moves the slider 5 to the right in the drawing to the end P2 of the outgoing path 2. At the end P2, the workpiece W is removed from the slider 5 by a transfer robot or the like, and the workpiece W is discharged from the conveyance system 1.

[0019] The circulation axis 8 includes a shift module 8a mounted on a table 10. The circulation axis 8 moves the slider 5 received from the outgoing path 2 upward in the drawing to the start end P3 of the returning path 3. The circulation axis 8 includes a drive mechanism that moves the shift module 8a in the direction of the circulation axis. The drive mechanism is a motor, a ball screw, a linear motor, or the like.

[0020] The return path 3 is linear and includes multiple return path modules 3a that are connected to each other. The return path 3 moves the slider 5 at its starting end P3 in the opposite direction to the outgoing path 2 (toward the left in the figure) to its end P4. The circulation axis 9 includes a shift module 9a mounted on a table 11. The circulation axis 9 includes a drive mechanism that moves the shift module 9a in the direction of the circulation axis. The drive mechanism is a motor, a ball screw, a linear motor, or the like. The circulation axis 9 moves the slider 5 received from the return path 3 downward in the figure to the start end P1 of the outgoing path 2. At the start end P1, the workpiece W is loaded again onto the slider 5 by a transfer robot or the like.

[0021] The position of each slider 5 moving along the circulation path 6 is controlled by a centralized controller such as a general-purpose PLC (Programmable Logic Controller) (not shown). The forward path module 2a, the return path module 3a, the shift modules 7a, 7b, and 7c of the shift shaft 7, and the shift modules 8a and 9a of the circulation shafts 8 and 9 are each equipped with a module controller capable of communicating with the centralized controller. The module controller controls the power supplied to multiple coils of the module so that the slider 5 moves according to commands from the centralized controller. The configuration of the module will be described later.

[0022] As shown in Fig. 2, the shift shaft 7 includes three shift modules 7a, 7b, and 7c mounted on a table 12. The three shift modules 7a, 7b, and 7c are linear and parallel to one another. The shift shaft 7 includes a drive mechanism that moves the three shift modules 7a, 7b, and 7c in the shift shaft direction (a direction perpendicular to the shift modules 7a, 7b, and 7c). The drive mechanism includes a motor and a ball screw, a linear motor, or the like.

[0023] The shift axis 7 moves three shift modules 7a, 7b, and 7c to switch from the normal transport position shown in Fig. 2(a) to the work input position shown in Fig. 2(b). In this way, as shown in Fig. 2(b), the slider 5 can be made to wait in front of the work processing device A, thereby shortening the downtime of the work processing device A. Furthermore, if processing by the work processing device A takes a long time, for example, two work processing devices A can be lined up (replace the work processing device B shown in Fig. 1 with the work processing device A), and the succeeding slider 5 can overtake the slider 5 input into the work processing device A, so that two workpieces W can be processed by the two work processing devices A.

[0024] After the workpiece W has been processed by the workpiece processing device A, the shift module 7a on which the slider 5 is mounted is returned by the shift shaft 7 to the normal transport position shown in FIG. 2(c).

[0025] At the normal transport position shown in Figures 2(a) and 2(c), first combined shift modules 7a and 7b, two selected from the three shift modules 7a, 7b, and 7c, are connected to the outgoing module 2a and the returning module 3a. At the work input position shown in Figure 2(b), second combined shift modules 7b and 7c, two selected from the three shift modules 7a, 7b, and 7c, are connected to the outgoing module 2a and the returning module 3a. This allows the slider 5 to pass through the outgoing path 2 and the returning path 3, regardless of the normal transport position and work input position of the three shift modules 7a, 7b, and 7c. Therefore, the slider 5 can be quickly returned to the start end P1 of the outgoing path 2, improving the throughput of the entire system.

[0026] Of the three shift modules 7a, 7b, and 7c, the bottom one is the forward-path shift module 7a, the top one is the return-path shift module 7c, and the center one is the forward-path / return-path combined shift module 7b. In the normal transport position shown in Figures 2(a) and 2(c), the forward-path / return-path combined shift module 7b is return path 3. In the work input position shown in Figure 2(b), the forward-path / return-path combined shift module 7b is forward path 2. Although four or more shift modules may be mounted on the shift shaft 7, the shift shaft 7 can be made smaller by using the forward-path / return-path combined shift module 7b in the center.

[0027] 3 shows an example in which three shift modules 7a, 7b, and 7c are switched to the shortcut position. In the shortcut position, the outgoing shift module 7a, on which the slider 5 is mounted, is connected to the return module 3a. In this way, if, for example, processing of only work processing device A is required, the slider 5 can be moved to the position of work processing device A, and then the circulation path 6 can be shortcut without moving to the positions of work processing devices B and C. This can improve the throughput of the entire system.

[0028] 4 shows a perspective view of the forward module 2a. The configurations of the return module 3a, the shift modules 7a, 7b, and 7c of the shift shaft 7, and the shift modules 8a and 9a of the circulating shafts 8 and 9 are also substantially the same as those of the forward module 2a. The forward module 2a has a plurality of coils 21 that form the stator 20 of the linear motor. Power is supplied to the plurality of coils 21 by a power converter such as a PWM inverter. The power converter is controlled by a module controller 24.

[0029] The outgoing module 2a is equipped with a linear guide 25 that smoothly guides the linear movement of the slider 5. A rail 26 of the linear guide 25 is attached to a base 28 of the outgoing module 2a. A carriage 27 of the linear guide 25 is attached to the slider 5. As shown in FIG. 5, the slider 5 is equipped with a magnet 29 that serves as a mover of a linear motor. The magnet 29 cooperates with the multiple coils 21 of the outgoing module 2a to generate thrust. A workpiece W is loaded onto the slider 5 via a pallet (not shown). (Second Embodiment)

[0030] 6 is a plan view of a transport system 31 according to a second embodiment of the present invention. The configurations of the outgoing path 2, the returning path 3, the circulation axes 8 and 9, and the slider 5 of the transport system 31 according to the second embodiment are the same as those of the transport system 1 according to the first embodiment, and therefore the same reference numerals are used and the description thereof will be omitted.

[0031] In the transfer system 31 of the second embodiment, two shift modules 33a and 33b are mounted on the shift shaft 32. The two shift modules 33a and 33b are an outgoing shift module 33a and a returning shift module 33b.

[0032] 7, the shift shaft 32 switches the outgoing shift module 33a on which the slider 5 is mounted between the normal transport position shown in Fig. 7(a) and the shortcut position shown in Fig. 7(b). Although not shown, the shift shaft 32 may also switch the outgoing shift module 33a to a work input position for the work processing devices A to C.

[0033] 7(a), the outgoing shift module 33a and the return shift module 33b of the shift shaft 32 are connected to the outgoing module 2a and the return module 3a. At the shortcut position shown in FIG. 7(b), the outgoing shift module 33a carrying the processed workpiece W is connected to the return module 3a.

[0034] According to the transport system 31 of the second embodiment, for example, when processing of only the work processing device A is required, the slider 5 can be moved to the position of the work processing device A, and then the circulation path 6 can be shortcutted without moving to the positions of the work processing devices B and C. Therefore, the throughput of the entire system can be improved.

[0035] The present invention is not limited to the above-described embodiment, and other embodiments may be used without departing from the spirit of the present invention. For example, although the above-described embodiment employs a circulating shaft system for circulating the sliders, an oval system may also be employed. Furthermore, although the above-described embodiment employs a horizontal circulating system for the sliders, the sliders may also be circulated vertically.

[0036] This specification is based on Japanese Patent Application No. 2024-047698, filed March 25, 2024, the entire contents of which are incorporated herein by reference.

[0037] DESCRIPTION OF SYMBOLS 1...Transport system, 2...Outward path, 2a...Outward path module, 3...Return path, 3a...Return path module, 5...Slider, 6...Circulation path, 7...Shift shaft, 7a, 7b, 7c...Three shift modules, 7a, 7b...First combination shift module, 7b, 7c...Second combination shift module, 7a...Outward path shift module, 7b...Forward path and return path combined shift module, 7c...Return path shift module, 21...Coil, 29...Magnet, 31...Transport system, 32...Shift shaft, 33a...Outward path shift module, 33b...Return path shift module, A to D...Workpiece processing device, W...Work

Claims

1. A transport system in which multiple sliders circulate along a circulation path including an outbound path with an outbound module and a return path with a return module, the transport system having a shift axis that moves at least three shift modules to switch between at least a normal transport position and a work input position for a work processing device, wherein at the normal transport position, two first combined shift modules selected from the at least three shift modules are connected to the outbound module and the return module, and at the work input position, two second combined shift modules selected from the at least three shift modules are connected to the outbound module and the return module.

2. The conveying system according to claim 1, wherein the at least three shift modules are composed of a forward shift module, a backward shift module, and a forward / backward shift module between the forward shift module and the backward shift module.

3. The conveying system described in claim 2, characterized in that the shift axis moves the three shift modules to switch them to a shortcut position, and at the shortcut position, the outgoing shift module and the return module, on which a slider is mounted, are connected, and the slider shortcuts the circulation path.

4. A conveying system in which a plurality of sliders circulate along a circulation path including an outward path with an outward path module and a return path with a return path module, the conveying system comprising a shift shaft that moves at least the outward path shift module and the return path shift module to switch between at least a normal conveying position and a shortcut position, wherein at the normal conveying position, the outward path shift module and the return path shift module are connected to the outward path module and the return path module, and at the shortcut position, the outward path shift module equipped with a slider and the return path module are connected, and the slider shortcuts the circulation path.

5. A conveying system according to claim 1 or 4, characterized in that the shift module is provided with a plurality of coils that can be energized, and the slider is provided with a magnet that cooperates with the plurality of coils to generate thrust.

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