Tray lifting device and tray conveying device provided with tray lifting device

Abstract

A tray lifting device (50) lifts a tray (11) conveyed so as to be mounted on a belt (20) during conveyance, and is provided with: lifting actuators (51) provided on both sides of the belt (20); a mounting member (52) provided so as to be liftable by the lifting actuator (51) and configured so as to be able to mount the conveyed tray (11) at a lowered position; and a fixing mechanism (61) that sandwiches the tray (11) together with the mounting member (52) in a state in which the mounting member (52) is raised.

Description

Technical Field

[0001] The present invention relates to a pallet lifting device and a pallet conveying device having the pallet lifting device. Background Art

[0002] At present, the following process is implemented in the manufacturing line, that is, a pallet conveying device composed of a free-flow conveyor is set up in a manner of connecting multiple machine tools, a pallet carrying workpieces is placed on the free-flow conveyor for transportation, and the machine tool at the transportation destination performs predetermined processing on the workpieces carried on the conveyed pallet.

[0003] In the above pallet conveyor, if there is a pallet with a workpiece being processed or not processed before the pallet with the processed workpiece, the pallet with the processed workpiece cannot be conveyed until the processing of the workpiece is completed, resulting in frequent pallet accumulation.

[0004] In order to solve this phenomenon, a lifting device has been proposed that lifts a pallet in the middle of conveyance so as to be mounted on a conveyor and allows other pallets to pass underneath the pallet (for example, refer to Japanese Patent JP5498943B).

[0005] In this lifting device, both sides of a pallet in the middle of being conveyed are gripped and lifted in this state, so that other pallets pass underneath, thereby eliminating the accumulation of pallets. Summary of the invention

[0006] However, in the above-mentioned pallet lifting device, the lifting head corrects the deviation of the pallet and holds it at the same time as the lifting starts, so the time for reliably correcting the deviation is too short. Therefore, when a workpiece is loaded on the pallet, the impact applied to the workpiece becomes stronger than when the time for correcting the deviation is longer, and there is a possibility that the workpiece deviates from the predetermined position on the pallet or falls.

[0007] An object of the present invention is to provide a pallet lifting device capable of eliminating deviation of a pallet during the process of lifting the pallet.

[0008] According to one embodiment of the present invention, a pallet lifting device for lifting a pallet being transported in a manner of being carried on a moving belt during transportation comprises: a lifting actuator, which is arranged on both sides of a belt in a manner of clamping the belt; a loading component, which is arranged to be able to be lifted and lowered by the lifting actuator and is constructed to be able to load the pallet being transported in a manner of being carried on the belt at a lowered position; and a fixing mechanism, which clamps the pallet together with the loading component when the loading component carrying the pallet is raised by the lifting actuator, and fixes the pallet to the loading component. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 It is a front view of a pallet conveying device equipped with a pallet lifting device according to an embodiment of the present invention.

[0010] Figure 2 A top view of a pallet conveying device having a pallet lifting device.

[0011] Figure 3 For along Figure 1 Cross-sectional view along line AA.

[0012] Figure 4 For along Figure 1 Cross-sectional view of line BB.

[0013] Figure 5 To indicate the tray lifting device Figure 1 Enlarged view of part C.

[0014] Figure 6 is a diagram showing a state in which the tray lifting device lifts the tray, which corresponds to Figure 4 .

[0015] Figure 7 is a diagram showing a state in which the tray lifting device lifts the tray, which corresponds to Figure 5 .

[0016] Figure 8 FIG. 1 is a diagram showing a state in which the fixing mechanism of the pallet lifting device fixes the lifted pallet, which corresponds to Figure 6 .

[0017] Fig. 9 FIG. 1 is a diagram showing a state in which the fixing mechanism of the pallet lifting device fixes the lifted pallet, which corresponds to Figure 7 . DETAILED DESCRIPTION

[0018] The best mode for carrying out the present invention will be described with reference to the accompanying drawings.

[0019] The pallet lifting device 50 in the present embodiment lifts up the pallet 11 being conveyed so as to be mounted on the moving belt 20 during the conveyance.

[0020] The following describes an example in which the pallet lifting device 50 is provided in the pallet conveyor device 10 that places the pallet 11 on the belt 20 and circulates the belt 20 to convey the pallet 11 .

[0021] Figure 1 as well as Figure 2 The pallet conveying device 10 is shown to include a pallet lifting device 50. Figures 1 to 9In each of the figures, three axes of X, Y, and Z are set to be orthogonal to each other, the X axis extends in a substantially horizontal lateral direction, the Y axis extends in a substantially horizontal front-back direction, and the Z axis extends in a vertical direction.

[0022] like Figure 1 as well as Figure 2 As shown, the pallet conveyor 10 includes a pair of belts 20 that are formed to be circulated and carry the pallet 11, and a drive mechanism 30 that circulates the belts 20 and conveys the pallet 11 carried on the belts 20. A conveying path for conveying the pallet 11 by the belts 20 is formed.

[0023] The pallet conveyor 10 places a pallet 11 carrying a workpiece (not shown) on a belt 20 for conveyance. The pallet conveyor 10 is used in a case where a machine tool 1 to 4 ( Figure 2 ), the circulation of the belt 20 is stopped, thereby stopping the conveyance of the pallet 11, and the workpiece (not shown) mounted on the pallet 11 is processed by the machine tools 1 to 4.

[0024] In addition, although Figure 2 , four machine tools 1 to 4 are provided on one side of the pallet conveyor 10 , but the number of machine tools 1 to 4 varies depending on the workpieces to be processed. Therefore, the number of machine tools 1 to 4 is appropriately increased or decreased according to the number of pallets 11 and the like.

[0025] like Figure 1 as well as Figure 2 As shown, the pallet conveyor 10 includes: a platform 9, which is arranged along the plurality of machine tools 1 to 4; a pair of plates 16, which are arranged on the platform 9 along the conveying path (X-axis direction) of the pallet 11 and are arranged in parallel with a predetermined interval in the width direction (Y-axis direction); and a plurality of support legs 19, which are erected on the platform 9 with a predetermined interval in the conveying path (X-axis direction). The pair of plates 16 are fixed to the support legs 19 above the platform 9.

[0026] like Figure 2 As shown, in the pallet conveyor 10, a pair of belts 20 are supported by each of the pair of plates 16. The pair of belts 20 support both ends of the pallet 11 in the width direction (Y-axis direction). In other words, the pallet 11 is carried so as to straddle the pair of belts 20.

[0027] Since the pair of belts 20 have the same shape, only one of the belts 20 will be described below. Figure 1 As shown, pulleys 22 for hanging belts 20 are respectively provided at both ends of the plate 16.

[0028] The belt 20 is hung around a pair of pulleys 22 provided at both ends of the plate 16 so that the carrier portions thereof are horizontal.

[0029] In addition, if Figure 3 As shown, an upper supporting component 17a and a lower supporting component 17b are respectively installed on each plate 16 of a pair of plates 16, 16, wherein the upper supporting component 17a supports the carrier portion of the belt 20 hung on the pulley 22, thereby preventing the carrier portion from loosening; and the lower supporting component 17b supports the return portion of the belt 20 hung on the pulley 22, thereby preventing the return portion from loosening.

[0030] The upper support member 17a and the lower support member 17b are screwed and mounted to the plate 16. The upper support member 17a and the lower support member 17b are provided with grooves 17c and 17d, respectively, which accommodate the belt 20 and prevent movement in the width direction (Y-axis direction).

[0031] like Figure 1 as well as Figure 3 As shown, the driving mechanism 30 for circulating the belt 20 includes a driving belt 23 around which the belt 20 is wound and a motor 31 for rotating the driving pulley 23 .

[0032] Specifically, if Figure 3 As shown, support plates 32 are respectively installed at the ends of the pair of plates 16, and the drive shaft 23a is pivotally supported on the support plates 32. A pair of drive pulleys 23 of the same shape and size are installed in the region between the pair of plates 16 in the drive shaft 23a.

[0033] The driving pulley 23 is arranged on the same plane as the pulley 22. Figure 1 As shown, the belt 20 deflected by the pulley 22 is hung on the driving pulley 23. In addition, the deflection pulley 24 for guiding the belt 20 hung on the driving pulley 23 to the lower supporting member 17b is pivotally supported on the supporting plate 32.

[0034] like Figure 3 As shown, the motor 31 is mounted on one support plate 32 and driven according to a command from a controller (not shown) to rotate the drive shaft 23a. The motor 31 rotates the drive shaft 23a, thereby rotating a pair of drive pulleys 23 mounted on the drive shaft 23a in the same direction at the same time, thereby causing the pair of belts 20 to circulate in the same direction.

[0035] The belt 20 in this embodiment uses a so-called toothed belt. Figure 1 The enlarged image of Figure 2As shown in the figures, on the belt 20, the projections and depressions 20a, 20b as the first engaging portion extending in the width direction (Y-axis direction) on the outer surface of the mounting surface of the tray 11 are formed in an alternating and continuous manner in the long side direction (X-axis direction).

[0036] like Figure 2 as well as Figure 3 As shown, the pallet 11 includes: a base 12, which is square in shape when viewed from above and is supported on both sides of the belt 20; a flange-shaped member 15, which is horizontally arranged on both sides of the width direction (Y-axis direction) of the lower part of the base 12 in a manner protruding from its side edge; a mounting member 13, which is arranged on the upper surface of the base 12 and carries a workpiece (not shown) processed by the machine tools 1 to 4; and a contact member 14, which is arranged on the lower surface of the base 12 and is in direct contact with the belt 20.

[0037] The shape of the mounting tool 13 varies depending on the type of workpiece to be transported. In addition, a plurality of pallets 11 including the mounting tool 13 are prepared in order to continuously transport a plurality of workpieces.

[0038] like Figure 1 As shown in the enlarged view of FIG. 1 , the contact piece 14 provided on the base 12 of the tray 11 is provided with concave-convex 14a, 14b as a second engaging portion that can engage with the concave-convex 20a, 20b of the belt 20. The concave-convex 14a, 14b of the contact piece 14 is formed to have the same shape and size as the concave-convex 20a, 20b in cross-sectional shape so as to engage with the concave-convex 20a, 20b of the belt 20.

[0039] When the tray 11 is mounted on the belt 20 and the contact 14 overlaps the belt 20, the concave-convex 14a and 14b formed on the contact 14 engage with the concave-convex 20a and 20b formed on the belt 20. As a result, the movement of the tray 11 in the X-axis direction (relative movement with the tray 11) independent of the belt 20 is prohibited. In other words, the tray 11 and the belt 20 move together.

[0040] like Figure 3 As shown, in a state where the belt 20 supports both sides of the tray 11 in the width direction via the contact pieces 14, the flange-shaped members 15 provided on both sides of the pedestal 12 pass over the plate 16 and protrude to the outside of the plate 16. In addition, a pair of guide members 36 are installed on the upper edge of the plate 16 in a manner of sandwiching the tray 11 including the flange-shaped members 15 from the outside in the width direction (Y-axis direction) at a predetermined interval.

[0041] The guide member 36 is formed so as to protrude to the outside in the width direction (Y-axis direction) relative to the flange-shaped member 15, and is attached to the upper edge of the plate 16. The guide member 36 is provided with a step portion 36a that faces the outer edge portion in the width direction of the flange-shaped member 15. Since the step portion 36a faces the outer edge of the flange-shaped member 15 with a slight gap, the movement of the tray 11 including the flange-shaped member 15 in the conveying direction is not hindered, and deviation in the width direction can be prevented.

[0042] In addition, a pressing member 18 is mounted on the upper surface of the portion protruding above the guide member 36. The pressing member 18 is formed, for example, by a flat plate extending to a position in the tray 11 that faces the upper surface of the flange-shaped member 15. A predetermined gap is provided between the pressing member 18 and the flange-shaped member 15 in the vertical direction (Z-axis direction), and between the flange-shaped member 15 and the guide member 36. In addition, the pressing member 18 is provided so as to face the side surface of the pedestal 12 in the Y-axis direction with a predetermined gap therebetween. This can prevent the pedestal 12 from moving in the width direction (Y-axis direction).

[0043] Furthermore, by providing the pressing member 18, the tray 11 mounted on the belt 20 is prevented from floating from the belt 20 and tilting relative to the belt 20. This maintains the engagement state between the concavoconvexities 14a and 14b formed on the contact piece 14 of the tray 11 and the concavoconvexities 20a and 20b formed on the belt 20, thereby preventing the belt 20 and the tray 11 from moving relative to each other. That is, the conveyance of the tray 11 by the belt 20 can be reliably implemented.

[0044] In the tray conveyor 10 , when the motor 31 is driven to circulate the belt 20 on which the tray 11 is mounted, the tray 11 moves while being mounted on the belt 20 and is conveyed by an amount equal to the movement amount of the belt 20 .

[0045] like Figure 1 , Figures 4 to 9 As shown, the pallet conveyor 10 further includes a pallet lifting device 50 that lifts the pallet 11 conveyed while being mounted on the belt 20 during the conveyance.

[0046] like Figure 4 As shown in the figures, the pallet lifting device 50 comprises: a pair of lifting actuators 51, which are arranged in a manner of clamping a pair of plates 16 in the Y-axis direction (arranged on the outside of the pair of plates 16); a loading component 52, which is arranged to be able to be raised and lowered by the lifting actuator 51, and is constructed to be able to load the pallet 11 that is transported in a manner of being loaded on the belt 20 at a lowered position.

[0047] like Figure 4as well as Figure 5 As shown, on the stand 9, a table 53 constituting the tray lifting device 50 is provided for each of the pair of tray lifting devices 50. On the table 53, a pair of support columns 54, 54 (see FIG. 1 ) separated in the conveying direction (X-axis direction) are provided. Figure 5 ), a mounting plate 56 is provided at the upper ends of a pair of pillars 54, 54.

[0048] The lifting actuator 51 in this embodiment is constituted by, for example, a fluid pressure cylinder and is arranged in the vertical direction (Z-axis direction). The rod 51 b penetrates the mounting plate 56 from below, and the upper part of the main body 51 a is mounted on the lower surface of the mounting plate 56 .

[0049] like Figure 5 As shown, the mounting member 52 is attached to the tip end side of the rod 51b of the lifting actuator 51. The guide member 36 is formed with a notch 36b into which the mounting member 52 and a fixing mechanism 61 described later can enter.

[0050] like Figure 4 As shown, the mounting member 52 has a mounting portion 52a, which is provided with a rod 51b ( Figure 5 ) installation; a loading portion 52b, which is formed at an end portion of the mounting portion 52a on the side of the plate 16 in a manner protruding upward, and is provided for mounting the tray 11.

[0051] The length W of the notch 36b of the guide member 36 (see Figure 1 as well as Figure 5 ) is formed to be longer than the length L1 in the conveying direction of the tray 11 (see Figure 1 ) long. In addition, Figure 5 As shown, the length L2 of the mounting member 52 is set to be equal to the length L1 ( Figure 1 Thereby, the tray 11 and the mounting member 52 can enter the notch 36b of the guide member 36, and the gaps between the tray 11 and the guide member 36 and between the mounting member 52 and the guide member 36 can be minimized.

[0052] like Figure 4 as well as Figure 5 As shown in FIG. 5 , when the rod 51b is sunken into the main body 51a, the mounting member 52 is in a lowered state. In this state, the flange-shaped member 15 of the tray 11 mounted on the belt 20 passes over the placement portion 52b of the mounting member 52. That is, when the mounting member 52 is lowered, the tray 11 mounted on the belt 20 can pass through the tray lifting device 50 without contacting the mounting member 52 or the pressing plate 62.

[0053] In a state where the tray 11 and the tray lifting device 50 are facing each other, that is, in a state where the flange-shaped member 15 of the tray 11 is located on the placement portion 52b of the mounting member 52, as shown in FIG. Figure 7 As shown in FIG. 5 , when the rod 51b is protruded upward from the main body 51a, as shown in FIG. Figure 6 As shown, the lifting actuator 51 causes the tray 11 to be mounted on the mounting portion 52b of the mounting member 52 and to rise. As a result, the tray 11 mounted on the mounting portion 52b of the mounting member 52 is separated from the notch 36b ( Figure 7 ).

[0054] The pallet lifting device 50 is provided with a fixing mechanism 61 that fixes the pallet 11 to the mounting member 52 when the mounting member 52 on which the pallet 11 is mounted is raised to a predetermined position by the lifting actuator 51 .

[0055] like Figure 4 as well as Figure 5 As shown, the fixing mechanism 61 in this embodiment includes: a lifting rod 64, which is provided on both sides of the lifting actuator 51 in the conveying direction and can move up and down relative to the mounting member 52; a pressing plate 62, which is installed on the upper end of the lifting rod 64 and is installed above the mounting member 52 in a manner separated from the mounting member 52 by a predetermined interval; a spring 63 ( Figure 5 ), which applies force in a manner to expand the interval between the pressing plate 62 and the mounting component 52; a sliding plate 66, which is installed at the lower end of the lifting rod 64; a collar 67a as a limiting component, which prohibits the further rise of the lifting rod 64 when the mounting component 52 carrying the tray 11 is raised to a predetermined position by the lifting actuator 51.

[0056] like Figure 5 As shown in FIG. 1 , a linear bush 67 for guiding the lifting rod 64 is mounted on the mounting plate 56. A linear bush 69 is also mounted coaxially with the linear bush 67 on the mounting portion 52a of the mounting member 52. In addition, a sleeve 67a is mounted on the mounting plate 56, which accommodates the linear bush 67 and serves as a limiting member. The sleeve 67a also has a function of protecting the linear bush 67. The length of the sleeve 67a in the Z-axis direction is longer than that of the linear bush 67.

[0057] The lifting rod 64 is inserted through the linear bush 67 and the linear bush 69 so as to be movable in the axial direction. The pressing plate 62 is bridged on the upper ends of the pair of lifting rods 64 .

[0058] The spring 63 is, for example, a coil spring interposed between the mounting member 52 and the pressing plate 62. A floating joint 57 is provided at the top end of the rod 51b of the lifting actuator 51. The floating joint 57 is attached to the mounting member 52. That is, the mounting member 52 is attached to the top end of the rod 51b via the floating joint 57.

[0059] A stripper bolt 58 is provided on the floating joint 57 so as to penetrate the mounting member 52 and coaxially with the rod 51b. The stripper bolt 58 is provided so as to extend the rod 51b and penetrates a stopper 59 mounted on the pressing plate 62. The head of the stripper bolt 58 abuts against the stopper 59, thereby preventing the mounting member 52 and the pressing plate 62 from opening by more than a predetermined value due to the biasing force of the spring 63 (see FIG. 1 ). Figure 5 ).

[0060] like Figure 7 As shown, a slide plate 66 is mounted across the lower portion of the pair of lift rods 64. When the pair of lift rods 64 rise, the slide plate 66 abuts against the sleeve 67a serving as a restriction member, thereby restricting further rise of the pair of lift rods 64.

[0061] Therefore, in the fixing mechanism 61 of such a structure, the pallet 11 rises in a manner of being mounted on the mounting member 52 of the pallet lifting device 50, and when the sleeve 67a abuts against the sliding plate 66, further rise of the pressing plate 62 provided on the pair of lifting rods 64 is restricted.

[0062] However, since the mounting member 52 is allowed to rise further from this state, when the rod 51b of the lifting actuator 51 further protrudes upward from the main body 51a, as shown in FIG. Figure 8 as well as Fig. 9 As shown, the distance between the pressing plate 62 and the mounting member 52 becomes narrower in a manner that overcomes the urging force of the spring 63. Then, finally, the placement portion 52b of the mounting member 52 and the pressing plate 62 clamp the flange-shaped member 15 in the tray 11. Thereby, the tray 11 is fixed to the mounting member 52.

[0063] In addition, if Figure 4 As shown in FIG. 1 , a pin 52c that protrudes toward the flange-shaped member 15 and tapers toward the tip is provided on the mounting member 52. In addition, a hole 15a is provided on the flange-shaped member 15 into which the pin 52c can enter.

[0064] In this embodiment, the pin 52c is formed at a diagonal position ( Figure 2 ), the inner diameter of the hole 15a is formed to be slightly larger than the outer diameter of the pin 52c.

[0065] Therefore, the distance between the pressing plate 62 and the mounting member 52 becomes narrower in a manner that overcomes the biasing force of the spring 63, and when the placing portion 52b of the mounting member 52 and the pressing plate 62 clamp the flange-shaped member 15 of the tray 11 ( Figure 8 ),like Figure 8 As shown in the enlarged view of FIG. 1 , the pin 52c enters the hole 15a in the flange-shaped member 15 of the tray 11. In this state, the tray 11 is mounted at a regular position on the mounting member 52. The "regular position" mentioned here means that the tray 11 is not tilted in the X-axis direction and the Y-axis direction, and is not offset relative to the X-axis direction and the Y-axis direction.

[0066] Furthermore, a preliminary guide member 71 is provided on the slide plate 66 to block the notch 36b formed in the guide member 36 (enter the notch 36b portion) when the mounting member 52 is raised. The preliminary guide member 71 is formed in a shape that surrounds the end portion of the flange-shaped member 15 in the tray 11 in the Y-axis direction from the side, top, and bottom. The preliminary guide member 71 has a cross-section that is substantially the same as the cross-section shape of the portion formed by the guide member 36 and the pressing member 18.

[0067] That is, the preliminary guide member 71 includes a side wall portion 71 a facing the outer side surface of the flange-shaped member 15 of the tray 11 being conveyed, and an upper plate portion 71 b facing the upper surface of the flange-shaped member 15 .

[0068] In addition, the preliminary guide member 71 is mounted on the sliding plate 66 via the support 72. When the sliding plate 66 abuts against the sleeve 67a, the preliminary guide member 71 that rises together with the sliding plate 66 enters the notch 36b in the guide member 36. In this state, the side surface of the flange-shaped member 15 of the tray 11 passing through the preliminary guide member 71 faces the side wall portion 71a with a slight gap in the width direction, and the upper surface of the flange-shaped member 15 faces the upper plate portion 71b with a slight gap in the vertical direction. Thereby, the movement of the tray 11 in the conveying direction is not hindered, and the deviation in the width direction, the floating of the tray 11 from the belt 20, and the inclination relative to the belt 20 can be prevented.

[0069] Next, a pallet conveying method performed by the pallet conveying device 10 will be described.

[0070] The pallet conveyor 10 sequentially loads a plurality of pallets 11 carrying workpieces for processing onto a circulating belt 20 for conveyance. The belt 20 is circulated by a driving mechanism 30. Specifically, the driving motor 31 rotates a pair of driving pulleys 23 simultaneously, and the pair of belts 20 hung on the driving pulleys 23 circulate in the same direction.

[0071] The pallet 11 carrying a workpiece (not shown) is carried on the belt 20 and is transported to the machine tools 1 to 4 ( Figure 2 ). In addition, when the pallet 11 is transported to the front of the machine tools 1 to 4, the circulation of the belt 20 is temporarily stopped, so that the pallet 11 carried on the belt 20 stops at a position corresponding to the machine tools 1 to 4. In this way, the workpiece (not shown) carried on the pallet 11 can be processed by the machine tools 1 to 4.

[0072] In addition, the workpiece|work which is not shown in figure is mounted on the mounting tool 13 of the pallet 11. In addition, the pallet 11 which mounted the workpiece|work is mounted on the belt 20 at the upstream side end part of the belt 20.

[0073] In addition, when the tray 11 is placed on the belt 20, the contact member 14 of the tray 11 overlaps with the belt 20. Figure 1 As shown in the enlarged view of FIG. 1 , the concavo-convex 14a, 14b formed on the contact member 14 engages with the concavo-convex 20a, 20b formed on the belt 20, thereby prohibiting the X-axis movement of the tray 11 independently of the belt 20. In addition, by providing the pressing member 18, the tray 11 mounted on the belt 20 is prevented from floating from the belt 20. This prevents the concavo-convex 14a, 14b from losing engagement with the concavo-convex 20a, 20b.

[0074] With such a structure, the pallet 11 is conveyed to the downstream side at a speed equal to the circulation speed of the belt 20. In addition, before being conveyed to the machine tool 1 arranged to face the belt 20, the circulation of the belt 20 can be temporarily stopped, thereby stopping the conveyance of the pallet 11.

[0075] While the pallet 11 and the machine tool 1 are stopped facing each other, the machine tool 1 processes a workpiece (not shown) mounted on the pallet 11 whose movement has stopped.

[0076] In addition, for example, when processing a workpiece loaded on the pallet 11, when the pallet 11 loaded with other workpieces not shown is loaded on the upstream end of the belt 20 at a distance equal to the distance between the machine tools 1 and 2, the next pallet 11 loaded with the other workpieces is placed on standby near the processing location.

[0077] When the workpiece mounted on the pallet 11 is processed by the machine tool 1, the pallet 11 on which the workpiece is mounted is conveyed toward the downstream side. Specifically, the belt 20 is circulated, and the pallet 11 is moved to the downstream side together with the belt 20.

[0078] Furthermore, when the pallet 11 is placed on standby at a standby position upstream of the processing position, the pallet 11 in the standby position moves to the processing position. Thus, for example, when the previous pallet 11 moves from the machine tool 1 and faces the machine tool 2, the subsequent pallet 11 faces the machine tool 1. Thus, the processing of the workpiece mounted on the pallet 11 in the machine tools 1 and 2 can be started immediately.

[0079] When the processing by the machine tools 1 and 2 is completed, the pallet 11 is further transported toward the downstream side together with the workpiece. Specifically, the belt 20 is circulated and the pallet 11 is further moved toward the downstream side. The conveying and stopping of the pallet 11 are repeated, and the pallet 11 carrying the workpiece that has been subjected to the necessary processing in the machine tools 1 to 4 is recovered from the downstream end of the belt 20 together with the workpiece.

[0080] Furthermore, since the pallet conveyor 10 includes the pallet lifting device 50 , the pallet 11 conveyed while being mounted on the belt 20 is lifted up in the middle of conveyance and detached from the belt 20 .

[0081] In the pallet lifting device 50, the mounting member 52 is lowered in the normal pallet conveying state (see Figure 4 Then, in the normal pallet conveying state, when the pallet 11 is conveyed while being carried on the belt 20, the flange-shaped member 15 protruding laterally from the plate 16 passes over the placement portion 52b in the placement member 52. Figure 4 In the normal pallet conveying state shown, the pallet 11 carried on the belt 20 is allowed to move through the pallet lifting device 50.

[0082] like Figure 5 As shown in FIG. 1 , a notch 36b is formed on the guide member 36 at a location where the tray lifting device 50 is provided. Figure 5 As shown in FIG. 1 , there is no pressing member 18 at the location where the tray lifting device 50 is provided. Thus, in order to lift the tray 11, the rod 51b of the lifting actuator 51 is protruded upward from the main body 51a while the tray 11 is facing the tray lifting device 50 (see FIG. 1 ). Figure 6 as well as Figure 7 ), thereby enabling the tray 11 mounted on the mounting portion 52b of the mounting member 52 to rise.

[0083] Thus, when the tray 11 is lifted, the lifted tray 11 is separated from the belt 20. Then, when the belt 20 is circulated in this state, the trays 11 other than the lifted tray 11 are conveyed by an amount equal to the movement amount of the belt 20.

[0084] For example, after conveying a predetermined amount of other pallets 11 except the lifted pallet 11, the carrying component 52 is lowered by the lifting actuator 51, and the lifted pallet 11 is lowered together with the carrying component 52 and loaded onto the belt 20 again, thereby increasing the interval with the preceding pallet 11 or decreasing the interval with the following pallet 11.

[0085] In addition, if Figure 6 as well as Figure 7 As shown, if the lifting height of the pallet 11 in the pallet lifting device 50 exceeds the height of the workpiece of the following pallet 11, the belt 20 is circulated in the state where the pallet 11 is lifted by the pallet lifting device 50, so that other pallets 11 following can pass under the lifted pallet 11. In this way, the conveying sequence of the pallets 11 can be changed.

[0086] For example, if the subsequent pallet 11 is passed under the pallet 11 lifted by the pallet lifting device 50, and the machine tool 4 ( Figure 2 ) and confronts the subsequent pallet 11, it is also possible to perform processing based on the machine tool 4 on the workpiece loaded on the subsequent pallet 11.

[0087] In the pallet lifting device 50 of this embodiment, a preliminary guide member 71 that blocks the notch 36b when the mounting member 52 is raised is provided on the slide plate 66. Thus, when the subsequent pallet 11 passes under the lifted pallet 11, it can pass through the notch 36b via the preliminary guide member 71.

[0088] Furthermore, when the subsequent tray 11 passes under the lifted tray 11, the flange-shaped member 15 of the tray 11 passing through the preliminary guide member 71 and the side wall portion 71a and the upper plate portion 71b of the preliminary guide member 71 are opposed to each other with gaps in the width direction and in the upper direction. This prevents the subsequent tray 11 from being obstructed from moving in the conveying direction, and prevents the tray 11 from being displaced in the width direction and from being lifted from the belt 20 and tilted relative to the belt 20. Therefore, the subsequent tray 11 can quickly pass under the lifted tray 11 while being carried on the circulating belt 20.

[0089] In addition, if the pallet 11 in the state of being lifted by the pallet lifting device 50 is aligned with the machine tool 3 ( Figure 2 ) confront each other, it is also possible to process the workpiece mounted on the pallet 11 which is lifted by the machine tool 3.

[0090] The pallet lifting device 50 includes a fixing mechanism 61 that clamps the pallet 11 together with the mounting member 52 and fixes the pallet 11 to the mounting member 52 when the mounting member 52 carrying the pallet 11 is lifted by the lifting actuator 51. This can prevent the workpiece mounted on the pallet 11 from shifting during processing and prevent obstruction during processing of the workpiece.

[0091] In particular, since the step portion 62a is formed on the pressing plate 62 to contact the side surface of the flange-shaped member 15 in the pallet 11 and restrict the movement of the pallet 11 in the width direction, even if a slight deviation occurs when the pallet 11 is mounted on the mounting member 52 in the lowered state, the deviation can be eliminated by the step portion 62a during the rising of the mounting member 52. In addition, when the pallet 11 rises further, the pallet 11 in the state where the deviation is eliminated is fixed to the mounting member 52 by the fixing mechanism 61. In this way, the workpiece mounted on the pallet 11 in the raised position can be processed without deviation.

[0092] That is, even if a slight deviation occurs in the pallet 11 when the pallet 11 is mounted on the mounting member 52 in the lowered position, the deviation can be eliminated until the pallet 11 reaches the raised state, so that processing based on high positioning can be performed.

[0093] In addition, in the tray lifting device 50, as Figure 4 As shown in FIG. 1 , a pin 52c tapering toward the top is provided on the mounting member 52 so as to protrude toward the flange-shaped member 15. In addition, a hole 15a into which the pin 52c can enter is provided on the flange-shaped member 15. Figure 8 As shown in FIG. 1 , when the mounting portion 52 b of the mounting member 52 and the pressing plate 62 clamp the flange-shaped member 15 in the tray 11, as shown in FIG. Figure 8 As shown in the enlarged view of FIG. 1 , the pin 52 c enters into the hole 15 a in the flange-shaped member 15 of the tray 11 .

[0094] Thus, even if the pallet 11 is slightly offset when being mounted on the mounting member 52, the pin 52c with a thin top can enter the hole 15a while the fixing mechanism 61 fixes the pallet 11 to the mounting member 52, thereby returning the pallet 11 to the proper position of the mounting member 52. In addition, since the pin 52c enters the hole 15a in this way, the displacement of the pallet 11 during the processing performed by the machine tool 3 can be further reliably prevented.

[0095] In addition, in the above-mentioned embodiment, a pair of pins 52c are formed at diagonal positions ( Figure 2), therefore, compared with a case where the pins 52c are located at symmetrical positions (for example, a case where the pins 52c are formed so as to be at the same position in the X-axis direction and spaced apart in the Y-axis direction), the interval between the pins 52c located on both sides in the width direction (Y-axis direction) of the tray 11 can be increased. This can reduce the amount of deviation of the tray 11 relative to the mounting member 52, and the tray 11 can be mounted at a more regular position.

[0096] In addition, although the above-mentioned embodiment illustrates an example in which the contact pieces 14 are provided on both sides of the lower portion of the pedestal 12 and the contact pieces 14 are overlapped with the belt 20, as long as the pallet 11 carried on the belt 20 can be transported, the contact pieces 14 may not be provided and the pedestal 12 may be directly carried on the belt 20.

[0097] In addition, in the above embodiment, if Figure 1 As shown in the enlarged view of FIG. 1 , the belt 20 is exemplified as a so-called toothed belt, that is, a so-called toothed belt having concave-convex 20a, 20b extending in the width direction formed alternately and continuously in the long side direction on the loading surface, that is, the outer surface, of the pallet 11. However, the belt 20 may be a belt without the concave-convex 20a, 20b as long as the pallet 11 loaded on the belt 20 can be properly transported.

[0098] In the above embodiment, the pair of pins 52c are formed on the mounting member 52, but the pins 52c may be provided at any position as long as the deviation of the tray 11 can be eliminated. Specifically, the pins 52c may be formed on the pressing plate 62.

[0099] In addition, in the above-mentioned embodiment, the pallet conveyor 10 connecting four machine tools 1 to 4 is described. However, although not shown in the figure, the pallet conveyor 10 can also be connected to more than five machine tools. Even if the processing steps based on the increase of machine tools increase, by providing a pallet lifting device 50 that lifts the pallet 11 being transported in a manner carried on the moving belt 20 during transportation, it is possible to change the interval (pitch) of the pallet 11 carrying the workpiece, thereby reducing the number of necessary pallets 11.

[0100] In addition, in the above-mentioned embodiment, the case where the pallet conveyor 10 is provided with one pallet lifting device 50 is described. However, the pallet conveyor 10 may be provided with two or more pallet lifting devices 50. Since two or more pallet lifting devices 50 are provided, even if the number of processing steps due to the increase of machine tools increases, the number of intervals (pitch) and sequence positions of the pallets 11 is increased, thereby enabling various conveying methods of the pallets 11.

[0101] Hereinafter, the configuration, operation, and effects of the embodiments of the present invention will be summarized and described.

[0102] The pallet lifting device 50 lifts the pallet 11 being transported in a manner of being carried on the moving belt 20 during transportation. The pallet lifting device 50 includes: a lifting actuator 51, which is provided on both sides of the belt 20 in a manner of sandwiching the belt 20; a loading member 52, which is provided to be able to be lifted and lowered by the lifting actuator 51, and is configured to be able to load the pallet 11 being transported in a manner of being carried on the belt 20 at a lowered position; and a fixing mechanism 61, which, when the loading member 52 carrying the pallet 11 is raised by the lifting actuator 51, clamps the pallet 11 together with the loading member 52, and fixes the pallet 11 to the loading member 52.

[0103] In this structure, since the fixing mechanism 61 fixes the pallet 11 to the carrying component 52 when the carrying component 52 carrying the pallet 11 is in a raised state, even if a slight deviation occurs when the pallet 11 is carried on the carrying component 52 in a lowered state, the deviation can be eliminated by eliminating the deviation during the rising process of the carrying component 52, thereby eliminating the deviation of the pallet 11 in the lifting stage.

[0104] In addition, in the pallet lifting device 50, the fixing mechanism 61 includes: a lifting rod 64, which is arranged on the mounting component 52 in a manner that it can move up and down; a pressing plate 62, which is installed at the upper end of the lifting rod 64 and is arranged above the mounting component 52 in a manner that is separated from the mounting component 52 by a predetermined interval; a spring 63 (force-applying component) that applies force in a manner that expands the interval between the pressing plate 62 and the mounting component 52; a sliding plate 66, which is installed at the lower end of the lifting rod 64; and a sleeve 67a (limiting component) that abuts against the sliding plate 66 when the mounting component 52 is lifted to a predetermined position by the lifting actuator 51, thereby prohibiting the lifting rod 64 from rising.

[0105] In this structure, when the mounting member 52 carrying the tray 11 is raised to a predetermined position by the raising actuator 51, the tray 11 is fixed to the mounting member 52. Therefore, while the mounting member 52 carrying the tray 11 is raised to a predetermined position, the deviation of the tray 11 can be corrected. Therefore, sufficient time for correcting the deviation can be ensured until the tray 11 is fixed to the mounting member 52.

[0106] In the tray lifting device 50 , a step portion 62 a is formed on the pressing plate 62 so as to face the side surface of the tray 11 and restrict movement of the tray 11 in the width direction.

[0107] In this configuration, even if a slight deviation occurs when the tray 11 is placed on the placing member 52 in the lowered state, the deviation can be eliminated by the step portion 62 a while the placing member 52 is ascending.

[0108] The tray lifting device 50 further includes a pin 52 c formed at a diagonal position of one of the mounting member 52 and the pressing plate 62 , and a hole 15 a formed in the tray 11 and into which the pin 52 c can enter.

[0109] In this structure, since the pin 52c enters the hole 15a while the fixing mechanism 61 fixes the pallet 11 to the mounting member 52, the pallet 11 can be returned to the proper position of the mounting member 52. In addition, since the pin 52c enters the hole 15a, the displacement of the pallet 11 during the processing performed by the machine tool 3 can be further reliably prevented.

[0110] The pallet conveyor 10 includes a pallet lifting device 50. In the pallet conveyor 10, a belt 20 is circulated on a pair of plates 16 disposed at a predetermined interval in the width direction, and flange-shaped members 15 are formed on both sides of the pallet 11 so as to pass over the pair of plates 16 and protrude to the outside of the plates 16 while being carried on the belt 20. The pallet lifting device 50 is installed so that the flange-shaped members 15 on both sides of the pallet 11 conveyed while being carried on the belt 20 can be carried on the carrying member 52 in a lowered state.

[0111] In this structure, after the other pallets 11 except the lifted pallet 11 are conveyed a predetermined amount, the lifted pallet 11 is lowered and loaded onto the belt 20 again, thereby increasing the interval with the preceding pallet 11 and decreasing the interval with the following pallet 11.

[0112] The pallet conveyor 10 further includes a guide member 36 which is mounted on the upper portion of the plate 16 and which restricts the movement in the width direction of the pallet 11 which is conveyed by being carried on the belt 20. The guide member 36 is provided with a notch 36b which can accommodate the lowered carrying member 52. The pallet lifting device 50 is provided with a preliminary guide member 71 which blocks the notch 36b when the carrying member 52 is raised.

[0113] In this state, the conveyance order of the trays 11 can be changed by causing another following tray 11 to pass under the lifted tray 11 while the tray lifting device 50 lifts the tray 11 .

[0114] The pallet conveying device 10 also includes: a first engaging portion, which is formed by projections and recesses 20a, 20b, which are arranged on the belt 20 and are arranged alternately and continuously in the long side direction; a second engaging portion, which is formed by projections and recesses 14a, 14b, which are arranged on the pallet 11 and can be engaged with the first engaging portion; a pressing member 18, which is arranged on the guide member 36 and prevents the pallet 11 loaded on the belt 20 from floating up from the belt 20 and tilting relative to the belt 20.

[0115] In this structure, since the pressing member 18 is provided, the tray 11 mounted on the belt 20 is prevented from floating from the belt 20 and tilting relative to the belt 20. As a result, the engagement state between the concavoconvexities 14a and 14b formed on the contact piece 14 of the tray 11 and the concavoconvexities 20a and 20b formed on the belt 20 can be maintained, thereby preventing the belt 20 and the tray 11 from moving relative to each other. That is, the conveyance of the tray 11 by the belt 20 can be reliably implemented.

[0116] Although the embodiments of the present invention have been described above, the above embodiments merely represent a part of application examples of the present invention and are not intended to limit the technical scope of the present invention to the specific configurations of the above embodiments.

[0117] This application claims priority based on Japanese Patent Application No. 2022-181586 filed with the Japan Patent Office on November 14, 2022, and all the contents of the application are incorporated into this specification by reference.

Claims

1. A pallet lifting device for lifting a pallet being transported in a manner of being carried on a moving belt during transport, wherein: have: A lifting actuator is arranged on both sides of the belt in a manner of sandwiching the belt; a loading member which is provided so as to be able to be raised and lowered by the lifting actuator and is configured to be able to load the pallet conveyed in a manner of being loaded on the belt at a lowered position; A fixing mechanism sandwiches the pallet together with the mounting member and fixes the pallet to the mounting member in a state where the mounting member on which the pallet is mounted is lifted by the lifting actuator.

2. The pallet lifting device according to claim 1, wherein: The fixing mechanism comprises: A lifting rod is provided on the mounting member in a manner capable of moving up and down; a pressing plate mounted on the upper end of the lifting rod and disposed above the mounting member at a predetermined interval therebetween; a force applying member configured to apply force in such a manner as to expand the interval between the pressing plate and the mounting member; A sliding plate mounted on the lower end of the lifting rod; A restriction member abuts against the slide plate when the mounting member is lifted to a predetermined position by the lifting actuator, thereby prohibiting the lifting rod from rising.

3. The pallet lifting device according to claim 2, wherein: The pressing plate is formed with a step portion that faces a side surface of the tray and restricts movement of the tray in a width direction.

4. The pallet lifting device according to claim 2, wherein: Also available: a pin formed at a diagonal position of either the mounting member or the pressing plate; A hole is formed in the tray and is capable of receiving the pin.

5. A pallet conveying device, comprising the pallet lifting device according to claim 1, wherein: A belt is circulatedly mounted on a pair of plates disposed at a predetermined interval in the width direction. A flange-like member is formed on both sides of the tray so as to pass over the pair of plates while being carried on the belt and protrude to the outside of the plates. The pallet lifting device is installed so that the flange-shaped members on both sides of the pallet conveyed while being carried on the belt can be carried on the carrying member in a lowered state.

6. The pallet conveying device according to claim 5, wherein: A guide member is further provided, the guide member being mounted on the upper portion of the plate and restricting movement in the width direction of the pallet being transported while being carried on the belt, The guide member is provided with a notch capable of accommodating the mounting member in a lowered state. The tray lifting device is provided with a preliminary guide member that blocks the notch when the mounting member is raised.

7. The pallet conveying device according to claim 6, wherein: Also available: A first engaging portion provided on the belt and formed of concave and convex portions provided alternately and continuously in the longitudinal direction; A second engaging portion, which is provided on the tray and is formed of a concave-convex portion that can engage with the first engaging portion; A pressing member is provided on the guide member and prevents the tray mounted on the belt from floating from the belt and tilting relative to the belt.

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