Tray lifting device, tray conveying device provided with tray lifting device, and tray conveying method using tray conveying device

Abstract

A tray raising device (29) is provided with: a lifting guide rail (16b) on which a tray (21) is movably mounted; a guide rail lifting mechanism (30) which lifts the lifting guide rail (16b) between a first position and a second position after the lifting guide rail (16b) is lifted from the first position; a tray fixing mechanism (50) for fixing the tray (21) to the lifting guide rail (16b); and an auxiliary guide rail (56) which is formed to have the same shape and size as the lifting guide rail (16b), and which reaches the first position when the lifting guide rail (16b) reaches the second position. In the tray conveying device (10), when a lifting guide rail (16b) is located at a first position, a tray raising device (29) is configured in a manner that the lifting guide rail (16b) is continuous with a fixed guide rail (16a). The tray conveying mechanism (40) is configured so as to be able to convey a tray carried on a fixed guide rail (16a), a lifting guide rail (16b) located at a first position, and an auxiliary guide rail (56) located at the first position along these guide rails.

Description

Technical Field

[0001] The present invention relates to a pallet lifting device for lifting a pallet loaded with workpieces and mounted on a guide rail during transportation, a pallet conveying device including the pallet lifting device, and a pallet conveying method using the pallet conveying device. Background Art

[0002] At present, the following is implemented in a manufacturing production line, that is, a pallet conveying device having a free-flow conveyor is provided in a manner of connecting a plurality of machine tools. In addition, a pallet carrying a workpiece is loaded on the free-flow conveyor and conveyed to a machine tool, and the machine tool at the conveying destination performs a predetermined processing on the workpiece loaded on the conveyed pallet.

[0003] In such a pallet conveyor, if a pallet carrying a workpiece being processed or not processed exists before a pallet carrying a workpiece being processed, the pallet carrying the workpiece being processed cannot be conveyed until the processing of the workpiece is completed, resulting in frequent pallet congestion.

[0004] In order to solve this problem, a lifting device has been proposed that lifts a pallet that is being carried on a free-flow conveyor and is in the middle of being conveyed from the free-flow conveyor and allows other pallets to pass underneath (for example, see Japanese Patent JP5498943B).

[0005] In the pallet lifting device, both sides of the pallet in the middle of conveying are grasped and lifted from the free flow conveyor in this state, so that other pallets are loaded on the free flow conveyor for conveying and pass under it. In this way, the order of the pallets is changed to eliminate the accumulation of pallets. Summary of the invention

[0006] However, the above-mentioned pallet lifting device lifts the pallet from the free-flow conveyor after gripping the pallet being conveyed in a manner of being placed on the free-flow conveyor. Therefore, in a pallet conveying device in which the pallet is mounted on the guide rail in a manner that cannot be lifted, the pallet cannot be lifted from the guide rail.

[0007] Therefore, in the pallet conveying device in which the pallet is mounted on the guide rail in a manner that the pallet cannot be lifted, there is a disadvantage that the above-mentioned conventional pallet conveying device that grips and lifts the pallet cannot be used as it is.

[0008] Therefore, although there are pallet conveying devices that convey pallets by placing them on guide rails in a manner that prevents them from being lifted, such pallet conveying devices equipped with guide rails have an unsolved technical problem that the order of pallets placed on the guide rails cannot be changed.

[0009] An object of the present invention is to provide a pallet conveying device capable of lifting a pallet that is mounted on a guide rail and conveyed in an unliftable manner, and a pallet conveying device including the pallet lifting device.

[0010] According to one embodiment of the present invention, the pallet lifting device comprises: a lifting guide rail, which carries the pallet so that it can move; a guide rail lifting mechanism, which causes the lifting guide rail carrying the pallet to be lifted and lowered between a first position and a second position after rising from the first position; a pallet fixing mechanism, which fixes the pallet carried by the lifting guide rail that is moved to the first position to the lifting guide rail; an auxiliary guide rail, which is formed to have the same shape and the same size as the lifting guide rail and is lifted and lowered together with the lifting guide rail, and when the lifting guide rail reaches the second position, the auxiliary guide rail reaches the first position and carries the pallet so that it can move. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 A diagram showing a pallet lifting device in an embodiment of the present invention is shown along Figure 8 Cross-sectional view of line BB.

[0012] Figure 2 FIG. 1 is a diagram showing a state in which the lifting guide rail of the pallet lifting device according to the embodiment of the present invention rises together with the pallet, which is equivalent to moving along the pallet lifting device. Figure 7 FIG. 5 is a cross-sectional view of the GG line.

[0013] Figure 3 For along Figure 1 A cross-sectional view of line EE.

[0014] Figure 4 FIG. 1 is a diagram showing a state in which the lifting guide rail of the pallet lifting device according to the embodiment of the present invention rises together with the pallet, which is equivalent to moving along the pallet lifting device. Figure 2 FIG. 5 is a cross-sectional view of line FF.

[0015] Figure 5 for Fig.11 An enlarged view of part A of FIG. 1 is a view showing a state in which the lifting guide rail of the pallet lifting device in an embodiment of the present invention is lowered together with the pallet.

[0016] Figure 6 A diagram showing a state in which the pallet passes under the lifting guide rail after being raised.

[0017] Figure 7 A diagram showing a state in which the lifting guide rail rises together with the pallet.

[0018] Figure 8 A diagram showing a state where a pallet moves from a fixed rail to a lift rail.

[0019] Fig. 9 For Figure 8 Top view observed from the C direction.

[0020] Fig.10 For along Figure 5 Cross-sectional view of line DD.

[0021] Fig.11 This is the front view of the pallet conveying device. DETAILED DESCRIPTION

[0022] Next, the best mode for carrying out the present invention will be described with reference to the accompanying drawings.

[0023] exist Fig.11 , a pallet conveyor 10 of the present invention is shown. In each figure, the three axes X, Y, and Z are set to be orthogonal to each other, and 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. The structure of the pallet conveyor 10 will be described below with reference to the accompanying drawings.

[0024] In this embodiment, the case where the pallet conveyor 10 is installed in a manufacturing production line is used as an example for explanation. Fig.11 As shown, a plurality of processing tables 11, 12 are arranged in a row at predetermined intervals in the X-axis direction on a manufacturing production line (in Fig.11 Only two are shown in the figure). Each processing table 11, 12 is box-shaped, and a machine tool (not shown) is installed on the inner wall. The machine tool installed in each processing table 11, 12 sequentially performs various processes on the workpiece (not shown) conveyed by the pallet conveyor 10, and automatically manufactures the product.

[0025] The pallet conveying device 10 includes: a pallet guide rail 16, which connects a plurality of processing workbenches 11, 12 that are arranged in a manner dispersed between a starting point and an end point; one or more pallets 21, which are mounted on the pallet guide rail 16; and a pallet lifting device 29, which is arranged at a position opposite to the processing workbenches 11, 12 according to each processing workbenches 11, 12.

[0026] The plurality of processing tables 11 and 12 are arranged linearly in the X-axis direction. Standby workstations 13 and 14 are respectively provided below both ends (starting point and end point) on the X-axis of the pallet guide rail 16. A stand 15 extending in the X-axis direction and having the pallet guide rail 16 provided on the upper part is provided on the standby workstations 13 and 14 and the plurality of processing tables 11 and 12.

[0027] The tray guide rail 16 in this embodiment is a commercially available linear motion guide rail. The tray guide rail 16 has a fixed guide rail 16a (see Fig.10etc.), which is fixed on the stand 15 via the support table 17; the lifting rail 16b (refer to Figure 1 etc.), which rises and falls together with the guide rail lifting mechanism 30 described later. Figure 3 to Figure 11 As shown, the support table 17 includes: a base plate 17a extending in the conveying direction (X-axis direction) and screwed to the frame 15; and a support plate 17b erected on the base plate 17a so as to extend in the longitudinal direction (X-axis direction).

[0028] like Figures 5 to 8 As shown, on the support plate 17b, between the processing tables 11 and 12 ( Fig.11 ) The opposite positions are respectively provided with notches 17c into which the lifting guide rails 16b can enter.

[0029] With processing workbench 11, 12 ( Fig.11 ) and the tray lifting device 29 arranged in an opposite manner have the same structure. Figure 1 as well as Figure 2 As shown, the pallet lifting device 29 includes: an elevating rail 16 b which, together with the fixed rail 16 a, constitutes the pallet rail 16 ; and a rail elevating mechanism 30 which elevates the elevating rail 16 b .

[0030] like Figure 3 As shown, the lifting rail 16b uses a linear motion guide rail whose length W1 in the X-axis direction is slightly longer than the length L in the X-axis direction (transportation direction) of the tray 21 (base 23) described later. The length W2 in the X-axis direction of the notch 17c of the support plate 17b is set to be slightly longer than the length W1 of the lifting rail 16b. The fixed rail 16a is attached to the upper edge of the support plate 17b from which the notch 17c is removed.

[0031] The tray 21 is mounted on the tray rail 16 composed of the fixed rail 16a and the lifting rail 16b. Fig. 9 as well as Fig.10 As shown in the figure, the pallet 21 has: a linear motion block 22, which spans the pallet rail 16 (linear motion guide rail) and is configured to be movable on the pallet rail 16; a base 23, which is screwed to the linear motion block 22; a first locking member 24 and a second locking member 25, which are arranged at a position separated from the pallet rail 16 in the Y-axis direction on the lower side of the base 23 (in a manner separated from the linear motion block 22). A workpiece support portion 26 ( Fig.10 ). In addition, the details of the first locking member 24 and the second locking member 25 will be described later.

[0032] The linear motion block 22 is a commercially available motion block that is sold in pair with a linear motion guide rail (tray rail 16), for example. Preferably, the linear motion block 22 includes a roller retainer (not shown). By using the linear motion block 22 with a roller retainer, it is possible to significantly reduce the resistance to the movement of the tray 21 on the tray rail 16 while limiting the movement in the width direction (Y-axis direction). In addition, as Figure 1 as well as Figure 2 As shown in FIG. 1 , a groove 22a having a substantially trapezoidal cross section is formed on the linear motion block 22, and a guide rail engaging portion 16c having a substantially trapezoidal cross section provided on the upper portion of the tray guide rail 16 is inserted into the groove 22a. Thus, the movement of the linear motion block 22 in the Z-axis direction (vertical direction) relative to the tray guide rail 16 is restricted. That is, in this embodiment, the tray 21 (linear motion block 22) cannot be lifted from the tray guide rail 16.

[0033] like Figure 1 As shown in FIG. 1 and FIG. 2 , the guide rail lifting mechanism 30 is installed on the platform 15 and lifts the lifting guide rail 16b. Specifically, the guide rail lifting mechanism 30 makes the lifting guide rail 16b be in a first position ( Figure 5 as well as Figure 8 The position shown), and the second position rising from the first position ( Figure 6 as well as Figure 7 Positions shown). Figure 5 as well as Figure 8 In the first position shown, the tray 21 moved from the fixed rail 16a can be placed on the lift rail 16b.

[0034] like Figure 1 as well as Figure 2 As shown, the guide rail lifting mechanism 30 includes: a lifting platform 31 provided with a lifting rail 16 b ; a support platform 32 provided on the frame 15 and supporting the lifting platform 31 so as to be able to be lifted; and an actuator 34 for lifting the lifting platform 31 .

[0035] like Figure 1 , Figure 2 as well as Fig. 9 As shown in the figures, the support table 32 is provided on the tray rail 16 at intervals and is formed of a plate material erected on the stand 15. On the surface of the support table 32 facing the tray rail 16, a plurality of guide rails 36 extending in the vertical direction (Z-axis direction) are provided at predetermined intervals in the long side direction (X-axis direction) of the tray rail 16 (see Fig. 9 ).

[0036] like Figure 1 as well as Figure 2As shown, the lifting platform 31 includes: a flat vertical plate 31a, which is arranged to be parallel to the upright part of the support plate 32; an upper horizontal plate 31b, which is arranged on the upper part of the vertical plate 31a in a manner of horizontally protruding in the direction of separation from the support plate 32; and a lower horizontal plate 31c, which is arranged on the lower part of the vertical plate 31a in a manner of horizontally protruding in the direction of separation from the support plate 32, and is arranged to be parallel to the upper horizontal plate 31b.

[0037] The lifting platform 31 is configured to be able to be raised and lowered relative to the frame 15. A linear motion guide block 37 movably engaged with the guide rail 36 is mounted on the flat surface of the vertical plate 31a facing the support platform 32. The vertical plate 31a can thereby be raised and lowered along the guide rail 36.

[0038] like Fig. 9 As shown, the length of the lifting platform 31 in the conveying direction (X-axis direction) composed of the vertical plate 31a, the upper horizontal plate 31b and the lower horizontal plate 31c is formed to be substantially the same as the length W1 of the lifting rail 16b, and the length W1 of the lifting rail 16b is slightly longer than the length L of the tray 21 (base 23) in the conveying direction (X-axis direction). As a result, the lifting platform 31 can enter the notch 17c formed in the support plate 17b.

[0039] Here, if Figure 5 as well as Figure 8 As shown, the fixed rail 16a is not installed in the notch 17c, so there is no obstacle to the lifting and lowering of the lifting platform 31 that can enter the notch 17c. In addition, it is also configured so that when the lifting rail 16b is located at the first position continuous with the fixed rail 16a, the tray 21 can be quickly moved from the fixed rail 16a to the lifting rail 16b.

[0040] like Figure 1 as well as Figure 2 As shown, in this embodiment, a fluid pressure cylinder is used as the actuator 34 for raising and lowering the lifting platform 31. The actuator 34 is provided on the opposite side of the lifting platform 31 across the support platform 32, and the body 34b is mounted on the frame 15 so that the rod 34a faces upward.

[0041] like Figure 1 , Figure 2 as well as Fig. 9 As shown in FIG. 1 and FIG. 2 , one end of a connecting plate 38 is mounted on the top end of the rod 34a. The lifting platform 31 is mounted on the other end of the connecting plate 38.

[0042] When the rod 34a of the actuator 34 is lowered into the body 34b, the lifting platform 31 is in the lowered position ( Figure 1 In this descending position, Figure 5as well as Figure 8 As shown, the lifting rail 16b provided on the lifting platform 31 is located at a first position continuous with the fixed rail 16a. The upper horizontal plate 31b is formed so as to be Fig. 9 ) is square in shape.

[0043] On the contrary, when the rod 34a of the actuator 34 is protruded from the body 34b, the lifting platform 31 is lifted up to the raised position ( Figure 1 Along with this, the lifting guide rail 16b provided on the lifting platform 31 also rises to a second position which is higher than the first position.

[0044] In addition, the pallet lifting device 29 further includes an auxiliary rail 56, which is raised and lowered together with the lifting rail 16b and is provided so as to be continuous with the fixed rail 16a at the second position after the lifting rail 16b is raised (the raised position after the lifting platform 31 is raised). The auxiliary rail 56 is configured so as to be able to carry the pallet 21 moved from the fixed rail 16a while being continuous with the fixed rail 16a.

[0045] The auxiliary rail 56 is formed of a linear motion guide rail similar to the fixed rail 16a and the lifting rail 16b. The auxiliary rail 56 is provided below the lifting rail 16b and is provided on the lifting platform 31 in parallel with the lifting rail 16b.

[0046] The lifting platform 31 of this embodiment includes an upper horizontal plate 31b and a lower horizontal plate 31c ( Figure 1 as well as Figure 2 ). In addition, the above interval is set to be the same as the interval in the vertical direction between the fixed guide rail 16a and the lifting guide rail 16b at the second position. In addition, the lifting guide rail 16b and the auxiliary guide rail 56 are formed to have approximately the same length. In addition, the lower horizontal plate 31c is installed in parallel below the upper horizontal plate 31b.

[0047] When the lifting platform 31 thus constructed is raised by the guide rail lifting mechanism 30, Figure 2 As shown, the lifting guide rail 16b arrives at the second position. In addition, the auxiliary guide rail 56 also rises together with the lifting guide rail 16b, as shown in FIG. Figure 4 As shown, the auxiliary rail 56 is continuous with the fixed rail 16a instead of the lifting rail 16b. In addition, when the auxiliary rail 56 is continuous with the fixed rail 16a, the auxiliary rail 56 can carry the pallet 21 moved from the fixed rail 16a.

[0048] like Figure 1 as well as Figure 2As shown in FIGS. 1 and 1B , the pallet lifting device 29 further includes a pallet fixing mechanism 50 that detachably fixes the pallet 21 moved from the fixed rail 16a to the lift rail 16b located at the first position to the lift rail 16b.

[0049] The pallet fixing mechanism 50 includes an actuator 53 which is provided on the lifting platform 31 and is capable of being freely engaged with and disengaged from the pallet 21 mounted on the lifting guide rail 16 b. Figure 1 as well as Figure 2 The actuator 53 shown has a rectangular parallelepiped body 53a and a rod 53b that can be retracted from the body 53a by fluid pressure. The actuator 53 is mounted on the lifting platform 31 with the rod 53b facing upward so as to engage with the second locking member 25 mounted on the tray 21.

[0050] like Figure 2 as well as Figure 4 As shown in FIG. 1 , a recess 25a is formed on the second locking member 25 of the tray 21 into which the top end of the rod 53b can enter. When the top end of the rod 53b enters the recess 25a, the rod 53b and the tray 21 are engaged, thereby limiting the movement of the tray 21 along the lifting guide rail 16b (relative to the movement of the lifting platform 31). Figure 1 as well as Figure 3 As shown, when the tip of the rod 53b is pulled out of the recess 25a, the engagement between the rod 53b and the tray 21 is cancelled, and the tray 21 can be freely moved along the lifting rail 16b (with respect to the lifting table 31).

[0051] like Fig.11 As shown, the pallet conveyor device 10 further includes a pallet conveyor mechanism 40 for conveying the pallet 21 along the pallet guide rail 16. The pallet conveyor mechanism 40 includes: an endless belt 41 configured to be engageable with the pallet 21 and provided along the pallet guide rail 16; and servo motors 42 and 43 as a circulation mechanism for circulating the belt 41.

[0052] exist Fig.11 In the pallet conveying device 10 shown, as an example, the following situation is shown, that is, mounting plates 13a, 14a are respectively installed on the standby work positions 13, 14 arranged on the lower side of the two ends in the X-axis direction of the platform 15 provided with the pallet guide rail 16, and servo motors 42, 43 are installed on the mounting plates 13a, 14a.

[0053] The servomotors 42 and 43 (circulation mechanism) are motors that rotate the rotating shafts 42a and 43a at any speed and can stop the rotating shafts 42a and 43a at any rotational position. The servomotors 42 and 43 are respectively mounted on the mounting plates 13a and 14a so that the rotating shafts 42a and 43a face the Y-axis direction. In addition, pulleys 42b and 43b of the same shape and size are respectively mounted on the rotating shafts 42a and 43a.

[0054] The belt 41 is hung around the pulley 42b and the pulley 43b. In addition, the interval between the standby workstations 13 and 14 or the position of the mounting plates 13a and 14a mounted on the standby workstations 13 and 14 is adjusted so that the belt 41 hung around the pulley 42b and the pulley 43b does not become loose.

[0055] When the servo motors 42 and 43 are driven synchronously by instructions from the controller 48, the rotating shafts 42a and 43a rotate in the same direction and at the same speed together with the pulleys 42b and 43b, and the belt 41 hung on the pulleys 42b and 43b circulates between the pulleys 42b and 43b.

[0056] In addition, although the present embodiment uses the servomotors 42 and 43 as the circulation mechanism and the servomotors 42 and 43 are mounted on the mounting plates 13a and 14a in the standby work stations 13 and 14 as an example, the servomotors 42 and 43 may be provided only on one side and only a pulley capable of idling may be provided on the other side. In addition, the pulleys 42b and 43b may be mounted on portions other than the mounting plates 13a and 14a.

[0057] In addition, as long as the belt 41 can be circulated, the circulation mechanism (servo motors 42 and 43) may not be provided at both ends of the pallet conveyor 10. Although not shown, for example, the servo motors 42 and 43 may be provided in the middle of the two ends instead of at both ends of the pallet conveyor 10.

[0058] like Figures 5 to 8 As shown, the belt 41 is a so-called toothed belt. Concave and convex portions 41a and 41b extending in the width direction as first engaging portions are formed on the belt 41 in a manner that is alternately continuous in the long side direction (X-axis direction). The belt 41 is hung around the pulley 42b and the pulley 43b in a manner that the concave and convex portions 41a and 41b face outward.

[0059] On the other hand, the tray 21 is provided with concave-convex portions 24a and 24b as second engaging portions that engage with the concave-convex portions 41a and 41b formed on the belt 41. Specifically, the concave-convex portions 24a and 24b are formed on the first engaging member 24 constituting the tray 21. The concave-convex portions 24a and 24b are continuously provided on the lower surface of the first engaging member 24 along the tray guide rail 16.

[0060] When the tray 21 is mounted on the fixed rail 16a and the lifting rail 16b at the first position, the first locking member 24 overlaps with the upper portion of the belt 41 wound around the pulleys 42b and 43b. As a result, the concave and convex portions 24a and 24b formed on the first locking member 24 engage with the concave and convex portions 41a and 41b formed on the belt 41.

[0061] When the projections and recesses 24a and 24b of the tray 21 are engaged with the projections and recesses 41a and 41b of the belt 41, the movement of the tray 21 along the tray guide 16 (movement in the X-axis direction) relative to the belt 41 is restricted. When the belt 41 is circulated using the servo motors 42 and 43 while the projections and recesses 24a and 24b of the tray 21 are engaged with the projections and recesses 41a and 41b of the belt 41, the tray 21 moves together with the belt 41, and the tray 21 is transported along the tray guide 16.

[0062] like Figure 7 As shown by the solid arrow, when the tray 21 moves upward in the Z-axis direction together with the lifting guide rail 16b, the belt 41 does not move in the Z-axis direction, so the engagement between the concave and convex 24a, 24b of the first locking member 24 and the concave and convex 41a, 41b of the belt 41 is eliminated. Thus, even if the belt 41 is circulated, the tray 21 after being raised does not move together with the belt 41.

[0063] Thus, in the pallet conveying mechanism 40 of the pallet conveying device 10, as shown in FIG. Figure 5 as well as Figure 8 As shown, the tray 21 mounted on the fixed rail 16a and the lifting rail 16b at the first position continuous with the fixed rail 16a can be transported along the fixed rail 16 and the lifting rail 16b at the first position. Figure 6 as well as Figure 7 As shown, when the lifting guide rail 16b is raised from the first position to the second position, the tray 21 mounted on the lifting guide rail 16b cannot be transported.

[0064] In addition, in the pallet conveying device 10, the pallet lifting device 29 is provided with an auxiliary rail 56 capable of carrying the pallet 21 moved from the fixed rail 16a. In addition, the pallet conveying mechanism 40 has a belt 41 which is provided so as to extend in the conveying direction and is formed across the notch 17c of the support plate 17b. Thereby, the concave-convex 24a, 24b of the first locking member 24 of the pallet 21 carried on the auxiliary rail 56 located at the position of the fixed rail 16a is engaged with the concave-convex 41a, 41b formed on the belt 41, so that the pallet 21 can be conveyed by the auxiliary rail 56 in a manner of crossing the notch 17c by the pallet conveying mechanism 40.

[0065] in addition, Figures 5 to 8 Symbol 44 in the figure is a support member 44 for supporting the upper portion of the belt 41 that is installed so as to cross the pulley 42b and the pulley 43b, and symbol 45 is a first mounting member 45 that is provided with a plurality of support members 44 at predetermined intervals in the long side direction and mounts the support members 44 on the support plate 17b.

[0066] in addition, Figures 5 to 8 Symbol 46 in the figure is a belt guide 46 for supporting the lower side of the belt 41 which is installed in a manner spanning the pulley 42b and the pulley 43b, and symbol 47 is a second mounting component 47 which is provided on the belt guide 46 in a manner spaced apart by predetermined intervals in the long side direction thereof and mounts the belt guide 46 on the support plate 17b.

[0067] Next, a pallet conveying method using the pallet conveying device 10 will be described.

[0068] Since the pallet conveyor 10 includes a plurality of pallet lifting devices 29 (two devices), by using the pallet conveyor 10 , it is possible to execute different processes for each pallet lifting device 29 .

[0069] The pallet conveying method using the pallet conveying device 10 includes: a pallet conveying step (see Figure 8 ), which transports the tray 21 mounted on the fixed rail 16a along the fixed rail 16a and moves it to the lifting rail 16b located at the first position; tray lifting process (refer to Figure 7 ), which causes the lifting rail 16b located at the first position carrying the tray 21 moved from the fixed rail 16a to rise and move to the second position; the tray fixing and maintaining process (refer to Figure 6 ), which fixes the pallet 21 on the lifting guide rail 16b located at the second position and maintains it for a predetermined time, and can process the workpiece (not shown) mounted on the pallet 21 by the machine tools of the processing workbenches 11 and 12; the pallet lowering process (refer to Figure 5 ), which lowers the lifting rail 16b carrying the tray 21 from the second position to the first position and connects with the fixed rail 16a. Each tray lifting device 29 repeatedly implements the above process according to each device. Below, each process is described in detail.

[0070] <Pallet conveying process> In this process, the tray 21 mounted on the fixed rail 16a or the tray 21 moved from the lifting rail 16b located at the first position and mounted on the fixed rail 16a is transported along the fixed rail 16a.

[0071] like Figure 8 As shown, regarding the tray 21 mounted on the fixed rail 16a or the lifting rail 16b at the first position, the concave-convex 24a, 24b of the first locking member 24 formed on the tray 21 engages with the concave-convex 41a, 41b of the belt 41. Fig.11 ) are synchronously driven to circulate the belt 41, thereby being able to convey the pallet 21 along the pallet rail 16 composed of the fixed rail 16a and the lifting rail 16b.

[0072] When the transported pallet 21 is moved to and mounted on the lifting rail 16b located at the first position of the pallet lifting device 29 facing the machine tools of the processing tables 11 and 12, the servomotors 42 and 43 are stopped to stop the circulation of the belt 41. Thus, the pallet 21 is maintained in the state of being mounted on the lifting rail 16b located at the first position.

[0073] <Pallet lifting process> In this step, the elevating rail 16b is raised together with the pallet 21 mounted on the elevating rail 16b so as to face the machine tools of the processing tables 11 and 12, and the elevating rail 16b is separated from the fixed rail 16a and moved to the second position.

[0074] As a specific step, first, Figure 3 As shown, when the tray 21 moves to a position where the lower surface of the second locking member 25 mounted on the tray 21 faces the rod 53b of the actuator 53 mounted on the lifting platform 31, the circulation of the belt 41 is stopped, thereby stopping the conveyance of the tray 21.

[0075] In this state, the rod 53b of the actuator 53 is protruded upward, and the tip of the rod 53b is inserted into the recess 25a provided in the second locking member 25 (see Figure 4 ). As a result, the rod 53 b of the actuator 53 engages with the recessed portion 25 a of the second locking member 25 , thereby restricting the movement of the tray 21 along the lifting rail 16 b (movement in the X-axis direction).

[0076] Thus, in a state where the free movement of the tray 21 is restricted, Figure 7 As shown by the solid arrow, the lifting rail 16b is lifted together with the tray 21. This lifting is implemented by causing the rail lifting mechanism 30, specifically, the rod 34a of the actuator 34 to protrude from the body 34b (see Figure 2 ). When the rod 34a of the actuator 34 is protruded, the lifting platform 31 is lifted together with the rod 34a, and the lifting rail 16b provided on the lifting platform 31 is lifted to the second position.

[0077] In this way, when the tray 21 moves upward in the Z-axis direction together with the lifting rail 16b and moves to the second position, the engagement between the projections and recesses 24a, 24b of the first locking member 24 of the tray 21 and the projections and recesses 41a, 41b of the belt 41 is released. As a result, the tray 21 is released from the state of being locked to the belt 41. In such a released state, even if the belt 41 is circulated, the tray 21 mounted on the lifting rail 16b cannot be moved.

[0078] <Pallet fixing and maintaining process> In this process, the pallet 21 mounted on the lifting rail 16b at the second position is kept in a restricted state relative to the lifting rail 16b for a predetermined time. In this process, the workpiece mounted on the pallet 21 is processed by a machine tool (not shown) in the processing workbench 11 or 12 as necessary.

[0079] In the previous step (tray lifting step), the engagement between the tray 21 and the belt 41 is released. Figure 2 as well as Figure 4 As shown, the state in which the tip of the rod 53 b of the actuator 53 in the tray fixing mechanism 50 is inserted into the recessed portion 25 a of the second locking member 25 attached to the tray 21 is maintained.

[0080] Therefore, the engagement state between the actuator 53 and the tray 21 is maintained, and the movement of the tray 21 mounted on the lifting rail 16b along the lifting rail 16b is restricted. Thus, for example, even if the workpiece mounted on the rising tray 21 is processed, the tray 21 is prevented from shifting along the lifting rail 16b during the processing. Therefore, in this process, even if the workpiece is processed, the processing of the workpiece is not hindered.

[0081] In this way, since the movement of the pallet 21 is restricted in the pallet fixing and maintaining step, the workpiece (not shown) mounted on the pallet 21 can be processed by a machine tool (not shown) in the processing tables 11 and 12 .

[0082] <Pallet lowering process> In this step, the lifting rail 16b on which the tray 21 is mounted is lowered to the first position and connected to the fixed rail 16a.

[0083] As a specific procedure, in a state where the circulation of the belt 41 is stopped, the lifting guide rail 16b and the tray 21 are moved together as shown in FIG. Figure 5 The descent is performed by lowering the rod 34a into the guide rail lifting mechanism 30, specifically, the body 34b of the actuator 34 (see Figure 1 When the rod 34a of the actuator 34 descends, the lifting platform 31 descends together with the rod 34a, and the lifting guide rail 16b provided on the lifting platform 31 descends from the second position to the first position (refer to Figure 5 ).

[0084] When the circulation of the belt 41 is stopped, when the tray 21 moves downward in the Z-axis direction together with the lifting rail 16b and moves to the first position, the first locking member 24 in the tray 21 overlaps with the belt 41, and the concave and convex 41a, 41b of the belt 41 are engaged with the concave and convex 24a, 24b of the first locking member 24 installed on the tray 21. Thereby, the tray 21 is again locked to the belt 41, thereby restricting the movement of the tray 21 relative to the belt 41.

[0085] Then, make Figure 1 The rod 53b of the actuator 53 shown in the figure descends in the body 53a, so that the top end of the rod 53b is disengaged from the recessed portion 25a in the second locking member 25. As a result, the engagement between the rod 53b of the actuator 53 and the second locking member 25 provided on the pallet 21 is eliminated, so that the pallet 21 can be moved relative to the lifting platform 31. In addition, the pallet descending process can also be referred to as a process for preparing the pallet conveying process.

[0086] The above steps are repeated, and the pallet 21 carrying the workpieces that have been subjected to necessary processing is unloaded at the terminal side standby station 14. In addition, regarding the starting side standby station 13, the pallet 21 carrying the workpieces that need to be reprocessed is sequentially loaded on the fixed rail 16a.

[0087] In this way, the pallet conveyor device 10 in the present embodiment can convey the pallet 21 along the pallet rail 16 by placing the pallet 21 on the pallet rail 16 and engaging with the circulating belt 41 .

[0088] Furthermore, since the pallet conveyor 10 includes the pallet lifting device 29 , the pallet 21 can be detached from the belt 41 by lifting the pallet 21 conveyed by engaging with the belt 41 during conveyance.

[0089] Furthermore, when the belt 41 is circulated in this state, the other trays 21 except the lifted tray 21 are conveyed by an amount equal to the movement amount of the belt 41. In this structure, after the other trays 21 except the lifted tray 21 are conveyed by a predetermined amount, the tray lowering process is performed, and the lifted tray 21 is lowered together with the lifting guide rail 16b and loaded on the belt 41 again, so that the interval with the preceding tray 21 can be expanded and the interval with the following tray 21 can be reduced.

[0090] In addition, the pallet conveyor 10 has a structure in which the concave and convex portions 41a, 41b of the belt 41 and the concave and convex portions 24a, 24b of the pallet 21 are engaged with each other, so the engagement can be easily eliminated by raising the pallet 21. Conversely, the pallet 21 can be engaged with the belt 41 again by simply lowering the pallet 21.

[0091] In addition, the pallet lifting device 29 includes an auxiliary rail 56 which is continuous with the fixed rail 16a and can carry the pallet 21 moved from the fixed rail 16a when the lifting rail 16b is in the second position. Figure 2 As shown in FIG. 1 , the lifting height of the tray 21 in the guide rail lifting mechanism 30 exceeds the height of the workpiece of the following tray 21. Figure 6 As shown, by circulating the belt 41 while the rail lifting mechanism 30 lifts the tray 21, other trays 21 locked to the belt 41 can pass under the tray 21 lifted by the auxiliary rail 56. In this way, the conveyance sequence of the trays 21 can be changed.

[0092] The pallet conveying method of this embodiment can implement the above-mentioned steps for each pallet lifting device 29. For example, if the pallet lifting device 29 in the processing workbench 11 lifts and fixes the lifting rail 16b together with the pallet 21 in the pallet fixing and maintaining step, during which the pallet lifting device 29 in the processing workbench 12 on the downstream side performs the pallet conveying step, such as Figure 6 As shown, the subsequent pallet 21 can pass through the auxiliary guide rail 56 below the pallet 21 lifted up in the processing table 11 .

[0093] This allows the pallet 12 located upstream of the processing table 11 to be conveyed to the processing table 12 on the downstream side so as to pass through the processing table 11 and face the processing table 12. That is, according to the pallet conveyor 10 of this embodiment, the order of the pallets 21 can be changed.

[0094] In the above embodiment, a so-called toothed belt is used as the belt 41, and the toothed belt is a toothed belt having concave and convex portions 20a and 20b extending in the width direction formed alternately and continuously in the long-side direction on the outer surface. However, as long as the pallet 21 is locked to the belt 41 and the pallet 21 loaded on the pallet guide rail 16 can be correctly transported, the belt 20 may be a belt without the concave and convex portions 20a and 20b.

[0095] In addition, in the above-mentioned embodiment, the pallet conveyor 10 connecting two processing workbenches 11 and 12 is described. However, although not shown in the figure, the pallet conveyor 10 may be connected to three or more processing workbenches. Since in the above-mentioned embodiment, a pallet lifting device 29 is provided that can lift the pallet 21 that is transported in a manner of being carried on the belt 20 during the transportation process, even if the number of processing workbenches increases and the number of processing steps increases, the intervals (pitch) between the pallets 21 carrying the workpieces can be changed, and the sequence of the pallets 21 can be changed. Thereby, the number of required pallets 21 can be reduced.

[0096] In addition, in the above-mentioned embodiment, the case where the pallet lifting device 29 is provided in a manner corresponding to the processing worktables 11 and 12 is shown. However, although not shown in the figure, the pallet lifting device 29 may be provided in a conveying path between the processing worktables 11 and 12 in a manner not corresponding to the processing worktables 11 and 12, which is different from the processing worktables 11 and 12. In this case, the pallet lifting device 29 is provided independently of the processing worktables 11 and 12, so even if the processing steps generated by the increase of the processing worktables 11 and 12 are increased, the position of changing the interval (pitch) and order of the pallets 21 can be appropriately adjusted. As a result, a variety of conveying methods of the pallets 21 can be performed.

[0097] Hereinafter, the configuration, operation, and effects of the embodiments of the present invention will be summarized and described.

[0098] The pallet lifting device 29 includes: a lifting guide rail 16b, which carries the pallet 21 so as to be movable; a guide rail lifting mechanism 30, which causes the lifting guide rail 16b carrying the pallet 21 to be lifted and lowered between a first position and a second position after rising from the first position; a pallet fixing mechanism 50, which fixes the pallet 21 moved to the lifting guide rail 16b located at the first position and carried on the lifting guide rail 16b; an auxiliary guide rail 56, which is formed to have the same shape and the same size as the lifting guide rail 16b, and is lifted and lowered together with the lifting guide rail 16b, and when the lifting guide rail 16b reaches the second position, the auxiliary guide rail 56 reaches the first position and carries the pallet 21 so as to be movable.

[0099] In the pallet lifting device 29 , even if the pallet 21 is mounted on the pallet rails 16 (the fixed rails 16 a and the lifting rails 16 b ) in a structure that does not allow the pallet 21 to be lifted, the pallet 21 can be lifted together with the lifting rails 16 b .

[0100] Furthermore, the tray lifting device 29 includes the auxiliary rail 56 which, when lifting the lifting rail 16b, reaches the first position where the lifting rail 16b existed before lifting, so that other trays 21 overtake the lifted tray 21. Thus, the order of the trays 21 can be changed.

[0101] Furthermore, since the pallet lifting device 29 includes the pallet fixing mechanism 50 for fixing the pallet 21 to the lifting rail 16b, the movement of the pallet 21 mounted on the lifting rail 16b relative to the lifting rail 16b can be restricted by the pallet fixing mechanism 50. This can prevent the pallet 21 from moving and detaching from the lifting rail 16b, or prevent the pallet 21 from changing its position and causing obstruction to the processing of the workpiece mounted on the pallet 21.

[0102] The pallet conveying device 10 includes: a pallet 21 configured to carry a workpiece; a fixed rail 16a that carries the pallet 21 so that it can move and cannot be raised or lowered; a pallet conveying mechanism 40 that conveys the pallet 21 carried on the fixed rail 16a; and a pallet lifting device 29 that is configured so that when the lifting rail 16b is located at the first position, the lifting rail 16b is continuous with the fixed rail 16a. The pallet conveying mechanism 40 includes: a belt 41 that is arranged on the fixed rail 16a and the lifting rail 16b located at the first position and is formed endlessly; and a circulation mechanism (servo motors 42, 43) that circulates the belt 41. The pallet conveying mechanism 40 is configured to convey the pallet 21 carried on the fixed rail 16a, the lifting rail 16b located at the first position, and the auxiliary rail 56 located at the first position along the rails in a state where the belt 41 and the pallet 21 are locked.

[0103] The pallet conveyor 10 further includes: a first engaging portion formed by concave and convex portions 41a and 41b provided on the belt 41 and provided alternately and continuously in the longitudinal direction; and a second engaging portion formed by concave and convex portions 24a and 24b provided on the belt 21 and capable of engaging with the first engaging portion (concave and convex portions 41a and 41b). In the pallet conveyor 10, when the pallet 21 and the belt 41 overlap, the first engaging portion (concave and convex portions 41a and 41b) engage with the second engaging portion (concave and convex portions 24a and 24b).

[0104] Since the pallet conveyor 10 has a structure in which the concave and convex portions 41a, 41b of the belt 41 and the concave and convex portions 24a, 24b of the pallet 21 are engaged, the engagement can be easily eliminated by raising the pallet 21. Conversely, the pallet 21 can be easily engaged with the belt 41 by simply lowering the pallet 21.

[0105] In the pallet conveying device 10 , a plurality of pallet lifting devices 29 are provided.

[0106] In the pallet conveying method using the pallet conveying device 10, a pallet conveying process, a pallet lifting process, a pallet fixing and maintaining process, and a pallet lowering process are implemented according to each pallet lifting device, wherein the pallet conveying process conveys the pallet 21 along the fixed guide rail 16a and moves it to the lifting guide rail 16b located at the first position; the pallet lifting process causes the lifting guide rail 16b located at the first position and carrying the pallet 21 moved from the fixed guide rail 16a to rise to the second position; the pallet fixing and maintaining process fixes the pallet 21 on the lifting guide rail 16b located at the second position and maintains it for a predetermined time; the pallet lowering process causes the lifting guide rail 16b carrying the pallet 21 to descend to the first position and be continuous with the fixed guide rail 16a.

[0107] Since a plurality of tray lifting devices 29 are provided, various conveying methods such as replacement of the order of the plurality of trays 21 and adjustment of the intervals can be realized.

[0108] 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.

[0109] This application claims priority based on Japanese Patent Application No. 2022-192656 filed with the Japan Patent Office on December 1, 2022, and all the contents of the application are incorporated into this specification by reference.

Claims

1. A pallet lifting device, comprising: A lifting rail that carries the pallet so that it can move; a guide rail lifting mechanism for lifting the lifting guide rail carrying the tray between a first position and a second position raised from the first position; a pallet fixing mechanism for fixing the pallet moved to the lifting rail located at the first position and carried thereon to the lifting rail; The auxiliary rail is formed in the same shape and size as the lifting rail and is lifted and lowered together with the lifting rail. When the lifting rail reaches the second position, the auxiliary rail reaches the first position and carries the tray so that it can move.

2. A pallet conveying device, comprising: The pallet is configured to carry a workpiece; A fixed guide rail that carries the tray so that it can move but cannot be raised or lowered; a pallet conveying mechanism for conveying the pallet carried on the fixed guide rail; The pallet lifting device of claim 1 is configured such that when the lifting rail is located at the first position, the lifting rail is continuous with the fixed rail. The pallet conveying mechanism comprises: a belt arranged in parallel on the fixed rail and the lifting rail located at the first position and formed to be endless; a circulation mechanism for circulating the belt, The pallet conveying mechanism is configured to convey the pallet mounted on the fixed rail, the lifting rail located at the first position, and the auxiliary rail located at the first position along these rails in a state in which the belt and the pallet are locked.

3. The pallet conveying device according to claim 2, wherein: Also available: A first engaging portion formed of concave and convex portions provided on the belt and provided in an alternating and continuous manner in the longitudinal direction; a second engaging portion formed of a concave-convex portion provided on the belt and capable of engaging with the first engaging portion; When the tray overlaps with the belt, the first engaging portion engages with the second engaging portion.

4. The pallet conveying device according to claim 2, wherein: The tray lifting device is provided in plurality.

5. A pallet conveying method, comprising: using the pallet conveying device according to claim 4, wherein: According to each of the pallet lifting devices, a pallet conveying process, a pallet lifting process, a pallet fixing and maintaining process, and a pallet lowering process are implemented. The pallet conveying process conveys the pallet along the fixed guide rail and moves the pallet to the lifting guide rail located at the first position. The pallet lifting step raises the lifting rail located at the first position and carrying the pallet moved from the fixed rail to the second position. The pallet fixing and maintaining step fixes the pallet on the lifting rail located at the second position and maintains the pallet for a predetermined time. The pallet lowering step lowers the lifting rail on which the pallet is mounted to the first position so as to be continuous with the fixed rail.

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