Pallet conveying device

Abstract

The present invention provides a pallet conveying device capable of moving only a pallet removably from a conveying lane when transferring the pallet between a pair of opposing conveying lanes. **Solution**: In a pallet conveying device comprising a rail body 14 extending linearly, one or more pallets 13 sliding along the rail body 14, and a conveyor belt 15 for sliding the one or more pallets 13 along the rail body 14, a rail width variable portion 20a is provided adjacent to at least one of one end and the other end of the rail body 14. The rail width variable portion 20a includes a pair of split rails 21, 22 extending parallel to the rail body 14, an open mode in which the pair of split rails 21, 22 are opened to the rail width of the rail body 14, and a closed mode in which the pair of split rails 21, 22 are closed to a width narrower than the rail width of the rail body 14.

Description

Technical Field

[0001] The present invention relates to a pallet conveying device for conveying a pallet on which a workpiece is mounted.

Background Art

[0002] In various manufacturing lines, a pallet conveying device is used to convey a pallet on which a manufactured product (workpiece) is mounted along a conveying rail toward each process. The pallet conveying devices disclosed in Patent Document 1 and Patent Document 2 convey a plurality of pallets on which workpieces are mounted along a pair of pallet rails provided in parallel to each other. This pallet conveying device has a mechanism for moving a pallet between a first pallet rail and a second pallet rail arranged in parallel.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the pallet conveying device disclosed in the above Patent Document 1, when transferring a pallet between a first pallet rail and a second pallet rail, a part of the rail on which the pallet is mounted is separated, and the rail is reciprocated between the first pallet rail and the second pallet rail. In such a structure where the entire rail is moved, the mechanism for moving the rail becomes complicated, and accurate positioning accuracy of the separated rail is required. Further, it is necessary to integrally configure the first pallet rail and the second pallet rail including the separation structure of the rail, and there are problems such as the entire apparatus becoming large-sized and being unable to flexibly respond to changes in the manufacturing line. Furthermore, it is not easy to shorten the cycle time of the entire conveying line in order to reciprocate the separated rail. On the other hand, regarding the second pallet rail, it only serves to collect the pallet for which the work has been completed on the first pallet rail, but it has the same configuration as the first pallet rail that requires conveyance accuracy. Thus, there is a part that has an excessive configuration with respect to the required functions, and it may not be possible to reduce the number of parts and costs as a whole.

[0005] In the pallet conveying device disclosed in the above Patent Document 2, pallet moving means having a rotating plate is provided between the first pallet rail and the second pallet rail, and by rotating the rotating plate together with the short rails provided around the rotating plate, the pallet mounted on the short rails is moved in a semicircular shape to transfer between the first pallet rail and the second pallet rail. In such a moving structure using a rotating plate, when transferring the pallet between the first and second pallet rails, a lifting means is required, and a rotating mechanism for rotating the rotating plate 180° in the horizontal direction is also required. Therefore, there are problems such as the structure of the pallet conveying device becoming complicated, reliability decreasing, and costs increasing.

[0006] Therefore, an object of the present invention is to provide a pallet conveying device capable of removably moving only the pallet from the conveying lane when transferring the pallet between a pair of opposing conveying lanes.

Means for Solving the Problem

[0007] In order to solve the above problems, the pallet conveying device of the present invention includes a conveying rail extending linearly, one or more pallets sliding along the conveying rail, and a conveying mechanism for sliding the one or more pallets along the conveying rail. In the pallet conveying device, a rail width variable part is provided adjacent to at least one of one end and the other end of the conveying rail, and the rail width variable part includes a pair of split rails parallel to the conveying rail, and the pair of split rails has an open mode of opening to the rail width of the conveying rail and a closed mode of closing to a width narrower than the rail width of the conveying rail. extends on the extension line of and bisects the rail width of the conveyor rail in the width direction parallel to arranged a pair of split rails, an open mode in which the pair of split rails opens to the rail width of the conveying rail, and a closed mode in which the pair of split rails closes to a width narrower than the rail width of the conveying rail.

Advantages of the Invention

[0008] According to the pallet conveying device of the present invention, when transferring a pallet from one conveying lane to another conveying lane, by switching the pair of split rails of the rail width variable part from the open mode to the closed mode, it is possible to simply and easily attach and detach only the pallet without requiring a complicated mechanism.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Embodiments for Carrying Out the Invention

[0010] Hereinafter, based on the accompanying drawings, embodiments of the pallet conveying device according to the present invention will be described in detail. FIG. 1 shows the overall configuration of a pallet conveying device 10 according to an embodiment of the present invention. The pallet conveying device 10 of the present embodiment has a first lane 11 extending in one direction, and one or two or more pallets 13 with workpieces (not shown) placed thereon are sequentially conveyed to predetermined processing positions along the first lane 11. A plurality of machine tools M1 to M5 for performing various processes on the workpieces are arranged at predetermined intervals along the first lane 11. A second lane 12 is provided in parallel with the first lane 11. The second lane 12 serves as a recovery lane for conveying and recovering only the pallet 13 after the workpiece has been removed by the first lane 11 in a direction opposite to the first lane 11. Further, by providing pallet pickup mechanisms P1 and P2 for transferring the pallets 13 to each other at both ends of the opposing first lane 11 and second lane 12, various processes can be performed while circulating a plurality of pallets 13. Note that the number of machine tools M1 to M5 and pallets 13 arranged along the first lane 11 is appropriately set according to the type and number of processes for the workpiece.

[0011] The first lane 11 includes a conveying rail (rail body) 14 extending linearly along a route for performing predetermined process operations on the workpiece, a pair of rail width variable portions 20a and 20b respectively provided adjacent to one end and the other end of the rail body 14, a conveying belt 15 arranged in parallel along one direction from one rail width variable portion 20a to the other rail width variable portion 20b, and a conveying mechanism (not shown except for the conveying belt 15) for driving the conveying belt 15 along one direction.

[0012] Figures 2 and 3 show the configuration of the rail width variable part 20a located at the end of the first lane 11. Since the rail width variable part 20b located at the start of the first lane 11 has the same configuration, the following description will be based on the rail width variable part 20a. The rail width variable part 20a includes a first split rail 21 and a second split rail 22 that are arranged in parallel so as to bisect the rail width of the rail body 14 in the width direction, and a rail opening and closing mechanism 23 that drives the first split rail 21 and the second split rail 22 to be openable and closable in the width direction. The first split rail 21 and the second split rail 22 are set such that their length dimensions are at least the same as or greater than the length dimension of the pallet 13 so as to completely accommodate the pallet 13.

[0013] The rail opening and closing mechanism 23 includes a first slide base 24 and a second slide base 25 that slidably support the first split rail 21 and the second split rail 22 in directions perpendicular to the longitudinal direction, respectively, and first and second slide driving parts 26 and 27 that slide the first slide base 24 and the second slide base 25 so as to be able to approach and separate from each other. The first and second slide driving parts 26 and 27 drive the first slide base 24 and the second slide base 25 in directions approaching each other and separating from each other by the expansion and contraction of an air cylinder or the like connected to the same drive source (not shown). Thereby, the first split rail 21 and the second split rail 22 can be switched between an open mode in which they are opened to the same rail width W1 as the rail width W of the rail body 14 as shown in Fig. 4(a) and a closed mode in which they are closed to a rail narrow width W2 narrower than the rail width W of the rail body 14 as shown in Fig. 4(b).

[0014] In order to ensure the opening and closing accuracy of the rail width W1 and the narrow rail width W2, in the present embodiment, the first and second slide driving units 26 and 27 are provided with an open mode stopper 28 and a closed mode stopper 29 for regulating the slide width of the first slide base 24 and the second slide base 25, respectively. As a result, as shown in FIG. 5(a), when set to the open mode, the first split rail 21 and the second split rail 22 open to the rail width W1, which is the same as the rail width W of the rail body 14, so that the pallet 13 can move on the first split rail 21 and the second split rail 22. As shown in FIG. 5(b), when set to the closed mode, the first split rail 21 and the second split rail 22 close to the narrow rail width W2, which is narrower than the rail width W of the rail body 14, so that it is possible to easily pick up the pallet 13 that has moved onto the first split rail 21 and the second split rail 22.

[0015] As shown in FIGS. 2 and 5, the pallet 13 includes a U-shaped slider portion 31 having a concave portion 33 straddling the rail body 14 and the rail width variable portion 20a on the lower surface side, and an L-shaped work table 32 fixed on the slider portion 31 for placing a work (not shown). At the bottom of one side portion 32a of the work table 32, an uneven portion 32b that meshes with the uneven portion 15a formed on the upper surface of the conveyor belt 15 is formed. The uneven portion 15a of the conveyor belt 15 will be described later. The opening width of the concave portion 33 provided in the slider portion 31 is set to substantially coincide with the rail width W1 of the pair of split rails 21 and 22 and the rail width W of the rail body 14 in the open mode. Therefore, the slide movement of the pallet 13 between the rail body 14 and the rail width variable portion 20a can be performed without hindrance. On the other hand, the narrow rail width W2 of the pair of split rails 21 and 22 in the closed mode is set to be narrower than the opening width of the concave portion 33, and a slight gap 35 is provided between the outer side surfaces of the split rails 21 and 22 and the inner side surface of the concave portion 33. This enables smooth picking up of the pallet 13.

[0016] On both outer surfaces of the rail body 14 and both outer surfaces of the first and second split rails 21 and 22, guide grooves 17 having a curved cross-section for guiding the movement of the slider portion 31 along the longitudinal direction are formed. On the other hand, on both inner surfaces of the recess 33 of the slider portion 31, sliding portions 34 that fit into the guide grooves 17 are provided. The sliding portions 34 are formed to protrude in accordance with the curved shape of the guide grooves 17, and a plurality of small spheres that are guided while rolling along the guide grooves 17 are arranged in a row. Since the pallet 13 is supported so as to be slidable only by the guide grooves 17 and the sliding portions 34 that engage with the guide grooves 17 with respect to the rail body 14 and the rail width variable portion 20a, smooth movement without resistance is possible.

[0017] As shown in FIG. 6, while a plurality of rows of guide grooves 17a and 17b having a curved cross-section are provided in parallel in the longitudinal direction on both outer surfaces (including both outer surfaces of the rail body 14) of the first and second split rails 21 and 22, a plurality of rows of sliding portions 34a and 34b each composed of small spheres that fit into the guide grooves 17a and 17b are arranged on both inner surfaces of the recess 33 of the slider portion 31, so that a slider capable of handling a higher load can also be used.

[0018] When the pallet 13 conveyed on the rail body 14 slides from the rail body 14 toward the rail width variable portion 20a, as shown in FIG. 5(a), the first and second split rails 21 and 22 in the rail width variable portion 20a are maintained in an open mode so as to have the same rail width W1 as the rail width W of the rail body 14.

[0019] On the other hand, when the pallet 13 reaches and stops at a substantially intermediate position of the rail width variable portion 20a, and when picking up the pallet 13 from this state and transferring it to the second lane 12 as shown in FIG. 1, as shown in FIG. 5(b), a shift is made from the open mode to the closed mode. As a result, the first and second split rails 21, 22 are closed in a direction narrower than the rail width W of the rail body 14. The rail narrow width W2 of the first and second split rails 21, 22 in the closed mode is such that a plurality of small spherical bodies forming the sliding portion 34 of the slider portion 31 come out of the guide grooves 17 formed in the first and second split rails 21, 22 and the fitting between the two is released, and it is set to be narrower than the rail width W of the rail body 14 by a width d. As a result, it becomes possible to pick up the pallet 13 from the first and second split rails 21, 22.

[0020] Also, when setting the pallet 13 in the rail width variable portion 20a, the closed mode is set in advance, and when the setting in the rail width variable portion 20a is completed, it is switched to the open mode. Note that the switching to the closed mode may be performed by a sensor that detects that the pallet 13 has reached and stopped at the rail width variable portion 20a, or may be manually switched by an operator. Note that the width d, which is the difference between the rail narrow width W2 of the first and second split rails 21, 22 in the closed mode and the rail width W of the rail body 14, may be about several millimeters.

[0021] The conveyance drive of the pallet 13 in the first lane 11 is performed by a conveyance belt 15 that extends from one rail width variable portion 20b along the rail body 14 to the other rail width variable portion 20a, as shown in FIGS. 1 and 2. The conveyance belt 15 is constituted by an endless belt, and is driven and controlled by a conveyance mechanism (not shown) so as to rotate and stop at a predetermined speed via pulleys 16 installed at both ends of a pair of rail width variable portions 20a, 20b. As the conveyance belt 15, a toothed belt that facilitates the positioning and placement of the pallet 13 can be used. This toothed belt is provided with uneven portions 15a in which grooves and protrusions attached in the width direction of the belt are continuously formed alternately in the longitudinal direction of the belt.

[0022] On the one hand, as described above, on the bottom of one side portion 32a of the workbench 32 of the pallet 13, an uneven portion 32b that meshes with the uneven portion 15a provided on the conveyor belt 15 is formed. The uneven portion 32b has a shape in which grooves and protrusions corresponding to the uneven portion 15a of the conveyor belt 15 are continuously arranged alternately. Therefore, by placing the pallet 13 on the rail body 14, the uneven portion 32b provided on the workbench 32 of the pallet 13 meshes with the uneven portion 15a of the conveyor belt 15, and the pallet 13 is conveyed on the conveying rail 14 by the driving of the conveyor belt 15. Further, when the pallet 13 is conveyed to the rail width variable portion 20a and the pallet 13 is picked up from the conveyor belt 15, the meshing between the uneven portion 15a and the uneven portion 32 is easily released. The pickup mechanisms P1 and P2 shown in FIG. 1 can be configured by independent devices using known means such as arms and grippers that can be lifted, lowered, and rotated, and can be arbitrarily installed according to the lengths and arrangement intervals of the first lane 11 and the second lane 12.

[0023] As shown in FIG. 1, the pallet 13 picked up by the pickup mechanism P1 can be easily transferred by simply moving it in parallel to the second lane 12 provided parallel to the first lane 11. The second lane 12 only needs to place the pallet 13 picked up by the pickup mechanism P1 as it is and return it in the direction opposite to the conveying direction of the first lane 11. For this reason, a rail like the first lane 11 is unnecessary, and it can be composed of only the conveyor belt 18. Note that partition plates are provided at predetermined intervals on the upper surface of the conveyor belt 18 to convey the pallets 13 in alignment.

[0024] As described above, in the pallet conveying device of the present invention, the width of the rail can be changed to a width that facilitates the attachment and detachment of the pallet by the rail width variable portion provided at one end or the other end of the rail body. For this reason, it is possible to easily transfer the pallet from one conveying lane to another conveying lane. Further, regarding the transfer of the pallet, since it is not integrated with the conveying rail and various pickup mechanisms can be used, it is possible to flexibly respond to changes in the manufacturing line such as the size of the pallet and the interval between the conveying rails. Further, since the rail width variable portion can be arranged separately from the rail body for performing predetermined process work on the workpiece, it can be arbitrarily arranged according to the installation location of the rail body. Note that by configuring the opening width of the pair of split rails in the rail width variable portion to be variable, it is possible to correspond to conveying rails having various rail widths.

Explanation of Signs

[0025] 10 Pallet conveying device 11 First lane 12 Second lane 13 Pallet 14 Rail body (conveying rail) 15 Conveying belt 15a Concavo-convex portion 16 Pulley 17 Guide groove 17a, 17b Guide grooves 18 Conveyor belt 20a, 20b Rail width variable portions 21 First split rail 22 Second split rail 23 Rail opening / closing mechanism 24 First slide table 25 Second slide table 26 First slide drive unit 27 Second slide drive unit 28 Open mode stopper 29 Closed mode stopper 31 Slider portion 32 Work table 32a One side portion 32b Protrusion and depression part 33 Recessed part 34 Sliding part 34a, 34b Sliding parts 35 Gap 36 Partition plate M1 to M5 Machine tools P1, P2 Pick-up mechanisms

Claims

1. A pallet conveying device including a linearly extending conveying rail, one or more pallets that slide along the conveying rail, and a conveying mechanism that slides the one or more pallets along the conveying rail, a rail width variable portion provided adjacent to at least one of one end and the other end of the conveying rail, The rail width variable section of the pallet conveying device comprises a pair of split rails extending on an extension line of the conveying rail and arranged in parallel so as to divide the rail width of the conveying rail in half in the width direction, and an open mode in which the pair of split rails are opened to the rail width of the conveying rail, and a closed mode in which the pair of split rails are closed to a width narrower than the rail width of the conveying rail.

2. 2. The pallet transport device according to claim 1, wherein the rail width varying unit maintains an open mode when the pallet moves from the transport rail to the divided rail, and enables a closed mode after the pallet moves onto the divided rail.

3. 3. The pallet conveying device according to claim 2, wherein when the rail width varying portion is in a closed mode, the pallet is detachable from the divided rails.

4. The pallet conveying device according to claim 3 , wherein the rail width varying section includes a pickup mechanism that attaches and detaches the pallet to and from the divided rails.

5. 2. A pallet conveying device according to claim 1, further comprising a recovery lane for the pallets arranged parallel to the conveying rail, and the pallets are transferred between the conveying rail and the recovery lane via the rail width variable section.

Images