Stacking device and stacking method

Abstract

To enable appropriate lamination of flexible sheet-like workpieces by suppressing bending thereof.SOLUTION: A lamination device 10 for stacking flexible sheet-like workpieces W on a bottom plate 41 of a storage box 12 comprises: a robot 13 provided with a hand 24 for gripping the workpieces W; and a temporary placing tool 14 in which the workpieces W conveyed on a conveyor 11 are temporarily placed by the robot 13. The temporary placing tool 14 has a temporary placing part 33 composed of a pair of rod-like members 36 arranged above the storage box 12. The rod-like members 36 are separated from each other so as to form a gap between the rod-like members 36. The robot 13 temporarily places the workpieces W in the temporary placing tool 14 so as to cover at least a part of the gap, and presses the parts of the temporarily placed workpieces W that cover the gap from above, thereby dropping the workpieces W through the gap to the bottom plate 41.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a stacking device and a stacking method. [Background technology]

[0002] BACKGROUND ART Some stacking devices for stacking workpieces are configured to directly feed workpieces transported by a conveyor from the end of the conveyor into a storage box (see, for example, Patent Documents 1 and 2). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 9-136720 [Patent Document 2] Japanese Patent Application Publication No. 10-324302 Summary of the Invention [Problem to be solved by the invention]

[0004] In the stacking device of the above type, if the workpieces are strong, specifically strong enough not to deform while falling, there is little possibility that the workpieces will be distorted when dropped, causing disturbance in their falling posture, and the variation in the falling posture and falling trajectory of the group of workpieces will be small. Therefore, the workpieces can be stacked properly on a predetermined placement part (such as the bottom of a storage box).

[0005] In contrast, when stacking soft, easily deformable workpieces such as rubber sheets or resin films, there is a concern that the workpieces may deform in various ways due to external forces when dropped, resulting in greater variation in the falling posture and trajectory of the workpieces. If a workpiece falls in an unexpected posture or trajectory, for example, the end of the workpiece may be more likely to be left bent. Subsequent workpieces may then be stacked on top of the bent workpiece, raising the following concerns: The bent portion may become distorted, reducing the percentage of non-defective products. Furthermore, as the number of bent workpieces increases, the balance of the stacked workpieces is likely to deteriorate. This deterioration in balance may result in an inability to stack the expected number of workpieces or a greater likelihood of the workpieces collapsing during transport. In other words, there is still room for improvement in stacking configurations to prevent bending of flexible sheet-like workpieces and properly stack them.

[0006] The present invention has been made in consideration of the above circumstances, and its main object is to realize a stacking device and stacking method that can prevent flexible sheet-like workpieces from bending and properly stack the workpieces. [Means for solving the problem]

[0007] The following describes means for solving the above problems.

[0008] First means: A stacking device that stacks a plurality of flexible sheet-like workpieces on a predetermined placing section, a jig disposed above the predetermined placement portion and on which the workpiece is temporarily placed; The jig is formed with a passage through which the work can pass when it falls onto the predetermined placement portion, The workpiece is temporarily placed on the jig so as to cover at least a portion of the passing section, and the portion of the temporarily placed workpiece that covers the passing section is pressed from above, causing the workpiece to fall through the passing section onto the specified loading section.

[0009] After temporarily placing a workpiece on a jig positioned above a predetermined placement unit, the portion of the workpiece covering the jig's passage is pressed from above. As a result, the workpiece falls through the passage and onto the predetermined placement unit. This configuration allows the workpieces to be aligned before they begin to fall, reducing variations in their postures at the time they begin to fall compared to a configuration in which the workpieces are directly introduced from a conveyor or other transport device. Furthermore, each workpiece is pressed and deforms in the same manner as it passes through the passage, thereby preventing the workpieces from deforming into various patterns, at least while passing through the passage. This suppresses the workpieces from losing their posture during the fall, making it easier to control the way they fall when flexible sheet-like workpieces are being stacked. Furthermore, even if the operating speed of the device (e.g., the pressing speed) fluctuates, this is unlikely to affect the posture of the workpieces as they fall. For these reasons, a configuration can be realized that reduces the chances of workpieces being stacked in a bent state and allows for proper stacking of workpieces.

[0010] Second means: A stacking method for stacking a plurality of flexible sheet-like workpieces on a predetermined placing section, a temporary placement process of temporarily placing the work on a jig that is located above the predetermined placement portion and has a passage through which the work can pass, so as to cover at least a part of the passage; a pressing step in which, after the temporary placement of the workpiece is completed, a portion of the temporarily placed workpiece that covers the passing section is pressed from above, thereby causing the workpiece to drop onto the predetermined placing section through the passing section; It has.

[0011] According to the stacking method shown in the second aspect, the chances of the workpieces being stacked in a bent state are reduced, and the workpieces can be stacked properly. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is a schematic view showing a stacking device according to a first embodiment. [Figure 2] FIG. 10 is a schematic diagram illustrating an example of a stacked state of workpieces. [Figure 3] FIG. 10 is a plan view showing the relationship between the storage box and the temporary placement jig. [Figure 4] FIG. 1 is a schematic diagram showing the stacking flow of workpieces. [Figure 5] Schematic diagram illustrating the posture of a workpiece when dropped. [Figure 6] Schematic diagram showing the motion trajectory of the robot. [Figure 7] Schematic diagram showing the stacking process. [Figure 8] FIG. [Figure 9] FIG. 6 is a schematic view showing a stacking device according to a second embodiment. [Figure 10] Schematic diagram showing the stacking process. [Figure 11] FIG. 10 is a schematic diagram showing a stacking state in the third embodiment. [Figure 12] FIG. [Figure 13] FIG. [Figure 14] FIG. DETAILED DESCRIPTION OF THE INVENTION

[0013] First Embodiment Hereinafter, a first embodiment embodied in a stacking device for stacking flexible sheet-like workpieces will be described with reference to the drawings. In this embodiment, a case where the stacking device is applied to a boxing process in a factory is illustrated. In view of the fact that the stacking device packs workpieces into boxes, the stacking device in this embodiment can also be said to be a boxing device.

[0014] As shown in Fig. 1, workpieces W machined in a preceding machining process are transported in order to a main boxing process by a conveyor 11. A stacking device 10 disposed in the boxing process is equipped with a robot 13 that packs the workpieces W transported by the conveyor 11 into storage boxes 12. The robot 13 has a robot body 21, which is a vertical articulated industrial robot, a servo amplifier attached to the robot body 21, and a controller 25.

[0015] The robot body 21 comprises a base fixed to a robot pedestal, a six-axis arm 22 attached to the base, and a hand 24, which is a tool, attached to the tip 23 of the arm 22. The arm 22 is made up of six connected movable parts, and each joint is equipped with a motor that drives the movable parts and an encoder that detects the rotation angle of each motor. The arm 22 is also equipped with a camera. The camera is connected to a controller 25, which can identify the position of the workpiece W from images captured by the camera.

[0016] The servo amplifier is provided with a communication unit that communicates with the controller 25 and a control unit that performs drive control of the motors of each joint based on commands from the controller 25 and rotation angles detected by the encoders. The controller 25 is composed of a motion controller and a host controller. The motion controller receives an operation instruction from the host controller, reads an operation program corresponding to the operation instruction from the program storage unit, and specifies a target operation position from the read operation program. Thereafter, it generates a target trajectory that smoothly connects the specified target operation position with the current position of the arm 22 (each movable part) of the robot 13, and sequentially transmits interpolated positions, which are positions obtained by dividing the target trajectory, to the servo amplifier.

[0017] The servo amplifier is provided with a position control section, a speed control section, a current control section, and a memory section for storing various information. The position control section detects the rotational position of the motor (i.e., the posture of the arm 22) based on information from the encoder. The position control section and the speed control section calculate the target torque and target rotational speed of each motor based on the deviation between the detected rotational position and the interpolated position included in the command received from the motion controller. The current control section determines the power (current, voltage, pulses) to be supplied to each motor based on the calculated target torque and target rotational speed, and supplies power to each motor.

[0018] A control program for packing is stored in the memory of the host controller. By driving the motors and the like based on this control program, the robot body 21 operates to pack the workpieces W transported by the conveyor 11 into the storage boxes 12 one after another. This control program may be stored in the memory when the robot 13 is manufactured, or may be downloaded via an internet line or the like.

[0019] Here, with reference to Figure 2, points to note when packing the workpieces W will be explained. The left side of Figure 2 illustrates an example of the workpieces W stacked properly, and the right side of Figure 2 illustrates an example of the workpieces W stacked improperly. When the workpieces W to be stacked are soft and easily deformed, the workpieces W are more likely to deform in various ways due to external forces such as resistance as they fall toward the bottom plate portion 41 of the storage box 12, compared to when the workpieces to be stacked are hard. It is expected that deformation of the workpieces W will be a factor that increases the variation in the falling posture and falling trajectory of the workpieces W.

[0020] If a workpiece W falls in an unexpected position or trajectory, there is a high possibility that, for example, the end of the workpiece W will be left bent. Furthermore, if subsequent workpieces W are piled up on top of the workpiece W, the following concerns arise: The bent portion may become warped, reducing the percentage of non-defective products. Furthermore, if the number of bent workpieces W increases, the height of the workpiece group may increase unnecessarily, potentially reducing the number of workpieces W that can be accommodated. Furthermore, if there is a certain amount of space between the storage box 12 and the group of workpieces W (see space S in FIG. 2 ), it is possible to insert one's hand into the space and efficiently remove the workpieces W. However, if there is no such space, there is a concern that the efficiency of manually removing the workpieces W may decrease. One of the features of this embodiment is that it is designed to address these issues. Below, this design is described with reference to FIGS. 1 and 3 .

[0021] As shown in Fig. 1, a temporary placement jig 14 on which a workpiece W transported by the robot 13 is temporarily placed is installed in front of the robot main body 21. The temporary placement jig 14 is located at the end of the conveyor 11, and the conveyor 11, robot main body 21, and temporary placement jig 14 are arranged so as to form an L shape when viewed from above. For convenience, the following description will be made with the direction when the robot main body 21 is viewed from the temporary placement jig 14 side as the "depth direction," the robot main body 21 side as the "rear side," and the temporary placement jig 14 side as the "front side."

[0022] As shown in FIG. 3 , the temporary placement jig 14 has a flat base 31 that is placed on the floor or the like. A positioning portion 31a for the storage box 12 is formed on the top surface of the base 31, and the position of the storage box 12 placed on this positioning portion 31a is restricted. The storage box 12 has a rectangular parallelepiped shape that is elongated in the depth direction and is open upward. This open portion (hereinafter referred to as an opening 46) is composed of two long sides 47 (the upper edges of the left and right plate portions 42 and 43 of the storage box 12) and two short sides 48 (the upper edge of the rear plate portion 44 and the upper edge of the front plate portion 45 of the storage box 12). Both the opening 46 and the bottom plate portion 41 of the storage box 12 are slightly larger than the workpieces W. In the following description, the plate portion 42 of the storage box 12 on the conveyor 11 side will be referred to as the "right plate portion 42" and the plate portion 43 on the opposite side will be referred to as the "left plate portion 43" as appropriate.

[0023] Two support columns 32 are provided on the front side of the positioning section 31a of the base 31 so as to stand up from the base 31. The support columns 32 are aligned in a direction perpendicular to the depth direction when viewed from above. The upper ends of the support columns 32 protrude above the storage box 12 placed on the base 31 (see FIG. 1), and a temporary placement section 33 is provided at the upper ends on which the workpiece W is temporarily placed with its surface facing up and down (hereinafter also referred to as a horizontal position).

[0024] The temporary storage section 33 has a pair of rod-shaped members 36 facing each other with a gap 35 between them, and the rod-shaped members 36 are attached to the support columns 32 in a cantilevered configuration. The tips of the rod-shaped members 36 face the robot main body 21, and they extend horizontally and parallel to each other. Specifically, the left and right rod-shaped members 36 face each other with a gap 35 between them. When viewed from above, each rod-shaped member 36 straddles two short side portions 48 that form an opening 46, and is arranged so that the center of the storage box 12 placed in the positioning section 31a is located between the rod-shaped members 36. The size of the gap 35 in the direction in which the rod-shaped members 36 are lined up (hereinafter referred to as the width direction) is smaller than the size of the opening 46 in the width direction, i.e., the distance between the long side portions 47. Although the details will be described later, in view of the fact that the workpiece W falls onto the bottom plate portion 41 of the storage box 12 through the gap 35, it can be said that the entrance of the storage box 12 is essentially narrowed by the rod-shaped members 36. When the workpiece W is temporarily placed so as to bridge over both rod-shaped members 36, at least a portion of the gap 35 is covered from above by the workpiece W.

[0025] Here, with reference to FIG. 4, the operation of the robot 13 (robot body 21) and the movement of the workpiece W when packing the workpiece W will be described. As shown in FIG. 4(a), the workpiece W transported by the conveyor 11 stops at the end of the conveyor 11 and is then handed over to the robot 13. Specifically, a groove 51 into which the hand 24 can be inserted is formed at the end of the conveyor 11. When the workpiece W to be handed over stops at the end, an edge (one end) of the workpiece W crosses above the groove 51 (see FIG. 1). In this embodiment, the pair of claws 24a (see FIG. 1) forming the hand 24 vertically sandwich the edge of the workpiece W to grip the workpiece W. In other words, the groove 51 ensures an insertion gap for the claws 24a of the hand 24 below the workpiece W.

[0026] The hand 24 is moved to a position (gripping position P1) where it can grip the one end of the workpiece W, and the hand 24 grips the center portion of the edge of the workpiece W. After gripping the edge of the workpiece W, as shown in FIG. 4(a) → FIG. 4(b), the robot 13 is operated to move the hand 24 horizontally toward the temporary placement jig 14 (left side) while maintaining its orientation, thereby transferring the workpiece W from the conveyor 11 to the temporary placement section 33. Specifically, the hand 24 is moved to a position (transfer position P2) beyond the temporary placement section 33. Note that the temporary placement section 33 is located slightly lower than the top surface of the conveyor 11, so that the workpiece W can be smoothly transported from the conveyor 11 to the temporary placement section 33.

[0027] When the workpiece W is temporarily placed across the two rod-shaped members 36, the one end (left end) held by the hand 24 and the other end (right end) on the opposite side thereof protrude from the temporary placement section 33. The protrusion amounts at both ends are equal, and the workpiece W is supported in a balanced manner by the rod-shaped members 36. In other words, the temporary placement position of the workpiece W is specified so that the protrusion amount of the workpiece W from the temporary placement section 33 is equal on both the left and right sides.

[0028] As described above in detail, the robot 13 is configured to pass the workpiece W received from the conveyor 11 through the temporary placement jig 14 rather than directly placing it in the storage box 12. As shown in Figures 4(b) and 4(c), after the workpiece W has been temporarily placed, the robot 13 is operated so that the hand 24 releases the grip of the workpiece W and moves the hand 24 above the portion of the workpiece W that covers the gap 35, more specifically, to a position (pressing preparation position P3) above the center CP (see Figure 3) of the gap 35 in the width direction. At this time, the posture of the arm 22 is changed so that the tip of the claw portion 24a (see Figure 1) faces downward.

[0029] After the hand 24 is placed in the pressing preparation position P3, the hand 24 is lowered to press the workpiece W from above, as shown in FIG. 4(c) → FIG. 4(d). Specifically, the hand 24 is moved to a position (lowered position P4) directly below the pressing preparation position P3 and below the gap 35. By pressing the portion of the workpiece W that covers the gap 35, the workpiece W is deformed and curved downwardly. In other words, the both edges (left and right ends) in the width direction are curved so as to approach each other.

[0030] As shown in Figures 4(d) to 4(e), after the hand 24 has finished pressing the workpiece W, i.e., after it has reached the lowered position P4, it immediately rises and moves away from the gap 35. Specifically, it moves to a position (initial position P0) that is set higher than the pressing preparation position P3. This prevents the bent workpiece W from getting caught on the hand 24 (arm 22) during the fall. When returning to the initial position P0, the posture of the arm 22 is changed so that the tip of the claw portion 24a (see Figure 1) faces sideways.

[0031] The workpiece W continues to deform under its own weight even after the hand 24 is released, and passes through the gap 35 in a curved state, as shown in FIG. 4(e) → FIG. 4(f). This downwardly convex curved state corresponds to the "predetermined posture." After passing through the gap 35, the workpiece W continues to fall while gradually returning to a horizontal state, as shown in FIG. 4(f) → FIG. 4(g). Then, as shown in FIG. 4(g) → FIG. 4(h), the workpiece W returns from the curved state to a horizontal state upon reaching the bottom plate portion 41 of the storage box 12.

[0032] By repeating the above-described process, the works W are piled up on the bottom plate portion 41.

[0033] Here, with reference to FIG. 5, the technical significance of bending the workpiece W so that it is convex downward will be described.

[0034] For example, as shown in FIG. 5(a), assuming a configuration in which the workpiece W is dropped while remaining horizontal, even a slight change in the orientation of the workpiece W can significantly affect its drop trajectory. For example, if the workpiece W tilts to the left, its drop trajectory is likely to deviate to the left, and if the workpiece W tilts to the right, its drop trajectory is likely to deviate to the right. In particular, if the workpiece W is easily deformed, its drop orientation can change significantly due to deformation of the workpiece W during drop due to its own weight or air resistance. In other words, if the workpiece W is dropped while remaining horizontal, there is a concern that the drop position will vary significantly due to variations in its drop orientation. Furthermore, there is a concern that the large variations in its drop orientation will be more likely to cause the bending described above. These concerns are likely to become more pronounced when the workpiece W is dropped in an enclosed space such as the inside of the storage box 12.

[0035] In contrast, as shown in this embodiment, when the workpiece W is dropped in a curved, downwardly convex state, even if it deforms during the drop due to its own weight or air resistance, such deformation will be patterned to some extent, and the variety of deformation patterns can be suppressed compared to when the workpiece W is dropped horizontally. Therefore, it can be expected that the drop posture will be less variable and the deviation of the drop trajectory will be smaller compared to when the workpiece W is dropped horizontally (see FIG. 5(b)). This is advantageous for properly stacking the workpieces W by reducing the variation in the drop position and suppressing bending of the workpieces W. Therefore, as shown in this embodiment, there is technical significance in controlling the drop posture of the workpiece W (at least the drop posture at the beginning of the drop) at least as it passes through the gap 35.

[0036] Furthermore, deliberately dropping the workpiece W after making the corners of the workpiece W less likely to collide with the bottom plate portion 41 has the technical significance of reducing the chance of the corners hitting the bottom plate portion 41 first and causing the bending described above. If the workpiece W collides with the bottom plate portion 41 while still convex downward, it can be expected that the workpiece W will return to a flat state due to its own weight. In other words, even if a configuration is adopted in which the workpiece W is actively curved, it is possible to avoid the increased effort required to return the workpiece W to a flat state.

[0037] In this embodiment, the operating range of the robot 13 (specifically, the arm 22) when packing the workpieces W is set outside the storage box 12. Here, with reference to FIG. 6, a supplementary explanation will be given of the operating target positions and target trajectories defined in the operation control program for packing. In the control program for packing the workpieces W, an initial position P0, a gripping position P1, a transport position P2, a pressing preparation position P3, and a lowering position P4 are set as operating target positions. The controller 25 drives each motor so that the hand 24 moves in the order of the initial position P0 → gripping position P1 → transport position P2 → pressing preparation position P3 → lowering position P4 → initial position P0. The target trajectory connecting the positions P0 to P4 is set outside the storage box 12, and the operating range of the arm 22 when moving the hand 24 along the target trajectory is also set outside the storage box 12. This prevents contact between the storage box 12 and the robot 13. In particular, even when moving to the lowering position P4 to drop the workpiece W, the robot 13 operates outside the storage box 12 and does not enter the storage box 12. Therefore, when performing this operation, there is no need to carefully adjust the movement trajectory while checking the distance from the storage box 12, which is preferable in terms of smoothing the movement of the robot 13. Therefore, even when the above operation is repeated, the efficiency can be suitably improved.

[0038] When the stacking device 10 packs the workpieces W into boxes, it is undesirable for the robot 13 to come into contact with the storage box 12 in order to avoid misalignment or damage to the storage box 12 and to protect the robot 13. In this regard, if the workpieces W temporarily placed above the opening 46 of the storage box 12 are dropped into the storage box 12, the workpieces W can be stacked properly without the robot 13 having to descend to the vicinity of the bottom plate portion 41 of the storage box 12. Therefore, the main operating range of the robot 13 can be set outside the storage box 12. This is preferable in terms of reducing the chances of contact between the robot 13 and the storage box 12.

[0039] After the workpieces W are temporarily placed on the temporary placement section 33 located above the storage box 12 (opening 46), the portion of the workpieces W covering the gap 35 of the temporary placement section 33 is pressed from above. As a result, the workpieces W fall through the gap 35 onto the bottom plate section 41 (corresponding to the "predetermined placement section") of the storage box 12. This configuration makes it possible to align the postures of the workpieces W before they start to fall, and reduces the variation in the postures of the workpieces W when they start to fall compared to, for example, a configuration in which the workpieces W are directly introduced from the conveyor 11. Furthermore, because each workpiece W is pressed and changes shape in the same way as it passes through the gap 35, it is possible to prevent the workpieces W from deforming into various patterns, at least while passing through the gap 35. This makes it easier to control the manner in which the workpieces W fall, especially when flexible sheet-like workpieces W are to be stacked, by suppressing the posture of the workpieces W from becoming unstable during the fall. Furthermore, even if the operating speed of the robot body 21 (the speed of pressure applied by the hand 24) fluctuates, this is unlikely to have an effect on the falling posture of the workpieces W. For the above reasons, it is possible to reduce the chances that the workpieces W are stacked in a bent state, thereby realizing a configuration that allows the workpieces W to be stacked properly.

[0040] As shown in this embodiment, by pressing the workpiece W at the center CP of the gap 35 in the arrangement direction (the width direction) of the rod-shaped members 36, it is possible to minimize the pressing force required to bend the workpiece W so that it is convex downward. This is preferable in terms of protecting the workpiece W. Note that if a difference in resistance (frictional resistance) occurs at the contact points between the rod-shaped members 36 and the workpiece W when bending the workpiece W so that it is convex downward, there is a high possibility that the position of the workpiece W will shift in the arrangement direction when bending the workpiece W. Pressing the workpiece W at the center CP is also preferable in order to make this less likely to occur.

[0041] In order to quickly drop the workpiece W temporarily placed on the temporary placement jig 14, it is preferable to configure the workpiece W to be pushed into a lowering position P4 set below the gap 35 rather than relying on the weight of the workpiece W. However, with such a configuration, the above-mentioned interference is likely to occur. Therefore, by immediately raising the arm 22 (hand 24) after the workpiece W reaches the lowering position P4, it is possible to realize a configuration in which the workpiece W is quickly lowered while preventing the workpiece W from being disturbed in its dropping posture.

[0042] <Second embodiment> In the first embodiment, the workpieces W are dropped onto the bottom plate 41 of the storage box 12 in a curved state that is convex downward. This is advantageous in suppressing variations in the dropped positions of the workpieces W and stacking the workpieces W properly. One of the features of the present embodiment is that it is designed to further reduce variations in the dropped positions of the workpieces W, specifically variations in the depth direction. First, with reference to FIG. 7, factors that cause variations in the depth direction will be described.

[0043] In the stacking device 10 shown in the first embodiment, the pressing point PP is set at the center CP of the gap 35. Therefore, if the workpiece W is properly placed in the temporary placement section 33, the center of the workpiece W is pressed by the robot 13. On the other hand, if the position of the temporarily placed workpiece W is shifted toward the back or front in the depth direction, the portion of the workpiece W that is shifted toward the front or rear from the center CP will be pressed. For example, if the workpiece W is pressed at a position shifted toward the rear, the edge of the workpiece W on the front side will fall slower than the pressed portion. This causes the posture of the workpiece W passing through the gap 35 to change so that it tilts toward the rear. As a result, an event may occur in which the drop position of the workpiece W is shifted toward the front. On the other hand, if the workpiece W is pressed at a position shifted toward the front, the edge of the workpiece W on the rear side will fall slower than the pressed portion. This causes the posture of the workpiece W to change so that it tilts toward the front. As a result, an event may occur in which the drop position of the workpiece W is shifted toward the rear. In other words, the work W may fall shifting toward the front or toward the back, resulting in the work W being stacked in a position closer to the back plate portion 44 or in a position closer to the front plate portion 45.

[0044] Here, if the direction of deviation of the drop position of the workpieces W can be aligned to either the front plate portion 45 side or the rear plate portion 44 side, the workpieces W can be stacked more appropriately. For example, stacking the workpieces along either the front plate portion 45 or the rear plate portion 44 makes it easier to ensure a gap between the stacked workpieces W and the inner surface of the storage box 12. Figure 8(a) shows a modification that takes this issue into consideration, in which the pressing point PP of the stacking device 10 shown in the first embodiment is biased toward the front side relative to the center CP of the gap 35 (see pressing point PPX). According to this modification, even if the position of the temporarily placed workpieces W varies in the depth direction, the descent of the rear edge of the workpieces W is delayed in most cases. In other words, the workpieces W tilt toward the front side. As a result, it is easier to align the direction of deviation of the drop position of the workpieces W toward the rear plate portion 44 side.

[0045] However, in such a modified example, if the above-mentioned deviation becomes large by accident, the workpiece W will tilt significantly toward the front and will be likely to lean against the rear plate portion 44 of the storage box 12 (see, for example, FIG. 8(b)). In other words, although it is possible to expect some effect in suppressing bending of the workpiece W, it is assumed that the advantage over the first embodiment will be reduced. One of the features of this embodiment is that it has been devised to take these circumstances into consideration. Below, with reference to FIG. 9, the characteristic configuration of this embodiment will be described, focusing on the differences from the first embodiment.

[0046] The temporary placement jig 14Y shown in this embodiment is similar to the temporary placement jig 14 shown in the first embodiment in that two rod-shaped members 36Y are positioned on the same horizontal plane and are bilaterally symmetrical. However, the rod-shaped members 36Y are not parallel to each other. Specifically, when viewed from above, each rod-shaped member 36Y is tilted inward from its base end with respect to a reference line FL extending in the depth direction (see tilt α). With this configuration, the width (size in the width direction) of the gap 35Y between the two rod-shaped members 36Y gradually decreases from the base end side of the rod-shaped member 36Y toward the tip end side of the rod-shaped member 36Y.

[0047] Furthermore, when the workpiece W is temporarily placed on the temporary placement section 33Y, the overlapping margin with respect to the rod-shaped member 36Y is larger in the narrow portion of the gap 35Y than in the wide portion of the gap 35Y. In this respect, the configuration is different from that of the first embodiment, in which the overlapping margin was constant throughout the entire depth direction.

[0048] In this embodiment, the pressing point PPY of the robot 13 is set to be biased toward the tip of the rod-shaped member 36Y, i.e., toward the robot 13. In other words, the workpiece W is pressed at the portion where the gap 35Y narrows in the depth direction. If the pressing point PPY were simply biased, the pressed workpiece W would tend to tilt toward the back in the depth direction for the same reasons as in the modified example shown in FIG. 8 above. In this regard, in this embodiment, the gap 35Y gradually narrows in the depth direction as described above. In other words, the engagement margin is smaller in the front portion farther from the pressing point PPY. Therefore, if the workpiece W descends even slightly in the front portion, it loses support from the rod-shaped member 36Y and the workpiece W descends rapidly. In other words, this acts to partially offset the delay in the fall of the workpiece W in the front portion, thereby reducing the delay in the fall in the front portion.

[0049] In this embodiment, the tilt α is set to a value that reduces the delay in dropping. As a result, as shown in Figure 10, if the pressing point PPY is shifted toward the front or back in the depth direction, the workpiece W will tilt toward the back in the depth direction, but this tilt is kept small. Therefore, bending of the workpiece W is suppressed, and the workpiece W can be stacked appropriately.

[0050] <Third embodiment> In the first and second embodiments, the workpiece W is temporarily placed so as to cover the gap 35 formed in the temporary placement section 33, and the portion of the workpiece W covering the gap 35 is pressed from above to drop the workpiece W through the gap 35 onto the bottom plate portion 41 of the storage box 12. This embodiment is similar to the first embodiment in that the portion of the workpiece W covering the gap 35 is pressed from above to drop the workpiece W through the gap 35 onto the bottom plate portion 41 of the storage box 12. However, the positional relationship between the temporary placement section 33 and the storage box 12 and the portion where the workpiece W is pressed differ from the first embodiment. Below, with reference to FIG. 11 , the characteristic configuration of this embodiment will be described, focusing on the above-mentioned differences, and a description of the configuration common to the first embodiment will be omitted. In the following description, when viewing the robot 13 from the front, the left rod-shaped member 36 will be distinguished as the "left rod-shaped member 36L" and the right rod-shaped member 36 will be distinguished as the "right rod-shaped member 36R."

[0051] 11(a), in the temporary placement section 33 of this embodiment, the right rod-shaped member 36R is located above the right plate portion 42 of the storage box 12. As a result, the distance in the width direction between the right rod-shaped member 36R and the right plate portion 42 of the storage box 12 is shorter than the distance in the width direction between the left rod-shaped member 36L and the left plate portion 43 of the storage box 12.

[0052] 11(a) to 11(b), the workpiece W is temporarily placed close to the right-side rod-shaped member 36R. Specifically, the workpiece W is temporarily placed so that the length of the engagement area with the left-side rod-shaped member 36L, i.e., the length of the portion of the workpiece W extending leftward beyond the left-side rod-shaped member 36L, is greater than the length of the engagement area with the right-side rod-shaped member 36R, i.e., the length of the portion of the workpiece W extending rightward beyond the right-side rod-shaped member 36R.

[0053] After the workpiece W is temporarily placed on the temporary placement section 33, as shown in Figures 11(b) and 11(c), the tip 23 (hand 24) of the arm 22, which is the "pressing section," moves above the workpiece W. In this embodiment, as shown in Figures 11(c) and 11(d), the pressing point PPA is set to a position biased toward the right-side rod-shaped member 36R, rather than in the center between the left-side rod-shaped member 36L and the right-side rod-shaped member 36R. In other words, as described above, the pressing position is set to the side where the overlap is relatively small.

[0054] 11(d) to 11(e), the workpiece W pressed by the tip 23 of the arm 22 is curved so as to be convex downward. Then, the right edge of the workpiece W passes through the gap 35 first, while still retaining an engagement margin with the left rod-shaped member 36L, so that the workpiece W as a whole tilts to the right. This posture tilted to the right corresponds to the "predetermined posture."

[0055] When the workpiece W is tilted to the right, it both rotates around the left rod-shaped member 36L and slides (slides) to the right while remaining in contact with the left rod-shaped member 36L. Then, the right edge of the workpiece W hits the right plate portion 42 of the storage box 12. After that, as shown in Figures 11(e) and 11(f), the engagement with the left rod-shaped member 36L becomes almost zero, and the workpiece W leaves the left rod-shaped member 36L and passes through the gap 35.

[0056] As shown in Figure 11(f) → Figure 11(g), as the workpiece W continues to fall, the downwardly convex part of the workpiece W and the right edge reach the bottom plate portion 41 of the storage box 12 before the left edge, and the left edge reaches the bottom plate portion 41 later.

[0057] In order to prevent bending caused by the workpiece W falling, it is more advantageous to control the posture of the workpiece W so that the edge of the workpiece W touches the inner surface of the storage box 12, as shown in this embodiment, than to control the posture of the workpiece W so that the corner of the workpiece W touches the inner surface of the storage box 12.

[0058] 11, variations in the dropping posture can be reduced, and the workpieces W can be stacked properly on the bottom plate portion 41. In particular, dropping the workpieces W along the right plate portion 42 makes it easier to stack the workpieces W along the right plate portion 42.

[0059] 11 illustrates a configuration in which the right edge of the workpiece W hits the right plate portion 42 of the storage box 12 during the fall, but the present invention is not limited to this. Depending on the size, weight, material, etc. of the workpiece W, the change in posture due to the rotation described above may become significant, making it difficult to control the falling posture of the workpiece W so that the right edge of the workpiece W hits the right plate portion 42 of the storage box 12. In such a case, it is preferable to configure the workpiece W during the fall to hit the bottom plate portion 41 of the storage box 12 or the workpiece W already stored while tilted at least to the right (preferably at an angle of less than 45° with respect to the horizontal plane), and then to bend due to its own weight, so that the workpiece W separates from the left rod-shaped member 36L and passes through the gap 35.

[0060] <Other embodiments> The present invention is not limited to the contents of the above-described embodiments, and may be implemented, for example, as follows. Each of the following configurations may be applied individually to the above-described embodiments, or a part or all of the configurations may be combined and applied to the above-described embodiments. It is also possible to arbitrarily combine all or a part of the various configurations shown in the above-described embodiments. In this case, it is preferable that the technical significance (effects to be exhibited) of each of the configurations to be combined is ensured.

[0061] In the above embodiments, the rod-shaped member 36 of the temporary placement jig 14 is arranged so as to bridge both long side portions 47 that form the opening 46 of the storage box 12, but this is not limited to this. The rod-shaped member 36 may also be arranged so as to bridge both short side portions 48. However, considering that setting the gap 35 between the rod-shaped members 36 to a certain degree of width is preferable for smoothly curving the workpiece W so that it is convex downward, there is technical significance in arranging the rod-shaped member 36 so as to bridge the long side portions 47. It is also possible to arrange the rod-shaped member 36 so as to bridge two orthogonal (intersecting) sides, i.e., the long side portion 47 and the short side portion 48.

[0062] In the above embodiments, the workpiece W temporarily placed on the temporary placement jig 14 is pressed by the hand 24 provided at the tip 23 of the arm 22. However, it is also possible to press the workpiece W by a portion of the tip 23 of the arm 22 other than the hand 24. For example, as shown in FIG. 12 , the hand 24B is disposed on the arm 22B (tip 23B) so that the tips of the claws 24aB face sideways, and the tip 23B is provided with a protrusion 23aB that protrudes downward from the hand 24B. When releasing the workpiece W and moving the hand 24B above the workpiece W, the hand 24B is rotated horizontally by 90° so that the tips of the claws 24aB face the rear or front side in the depth direction. Thereafter, by operating the arm 22B so that the tip 23B is lowered while keeping the orientation of the hand 24B unchanged, the workpiece W is pressed by the protrusion 23aB of the tip 23B. With this configuration, the chances of the claw portion 24aB hitting the workpiece W can be reduced.

[0063] In the first embodiment described above, the workpiece W temporarily placed on the temporary placement jig 14 is pressed by the arm 22 of the robot 13, causing the workpiece W to fall through the gap 35 onto the bottom plate 41 of the storage box 12. However, it is also possible to have the temporarily placed workpiece W fall by its own weight without being pressed. However, with such a configuration, the control of the curvature of the workpiece W becomes weaker, and the drop posture of the workpiece W may vary greatly. Therefore, it is preferable to have a configuration in which the curvature of the workpiece W is controlled by pressing the workpiece W, as shown in the first embodiment described above.

[0064] Alternatively, instead of using the arm 22 of the robot 13 to press the workpiece W, each rod-shaped member 36 may be rotatably supported on a shaft, and the rod-shaped members 36 may be rotated to move the workpiece W horizontally, thereby eliminating one of the left and right overlapping distances and allowing the workpiece W to fall through the gap 35. A modified example of this technical concept applied to the first embodiment will be specifically described below. In this modified example, similar to the second embodiment, the workpiece W is temporarily placed so that the overlapping distance between the right rod-shaped member 36 and the workpiece W is smaller than the overlapping distance between the left rod-shaped member 36 and the workpiece W. In this modified example, the rod-shaped members 36 are rotated in a first rotation direction (counterclockwise when viewed from the front of the robot 13) so that the workpiece W moves to the left. Then, when the overlapping distance between the workpiece W and the right rod-shaped member 36 becomes zero and the workpiece W starts to fall, the rotation of the rod-shaped members 36 is stopped or rotated in a second rotation direction (clockwise when viewed from the front of the robot 13) opposite to the first rotation direction. With this configuration, the workpiece W can be dropped onto the bottom plate portion 41 of the storage box 12 through the gap 35, and excessive tilting to the right can be prevented by promptly releasing the engagement between the left-side rod-shaped member 36 and the workpiece W.

[0065] In the above embodiments, when the tip 23 of the arm 22 reaches the lowered position P4 during pressing of the workpiece W, the tip 23 of the arm 22 is immediately raised, but this does not deny a configuration in which the arm 22 comes to a standstill after reaching the lowered position P4 and the tip 23 temporarily stays at the lowered position P4. However, in such a configuration, it is preferable to provide a wall or the like on the side of the hand 24 to prevent the bent workpiece W from getting caught on the hand 24 from the side.

[0066] In the above embodiments, the lowering position P4 of the tip 23 of the arm 22 is set below the gap 35 serving as the "passage section," but it is also possible to set the lowering position P4 within the gap 35 or within the storage box 12.

[0067] In the above embodiments, the temporary placement unit 33 is disposed above the opening 46 of the storage box 12, but this does not negate a configuration in which the temporary placement unit 33 is disposed inside the storage box 12. However, in order to set the operating range of the robot 13 outside the storage box 12 and reduce the chance of collision between the robot 13 and the storage box 12, it is preferable to dispose the temporary placement unit 33 above the opening 46, i.e., outside the storage box 12.

[0068] The inclination α (see FIG. 3) of the rod-shaped member 36 shown in the third embodiment may be increased to allow the portion of the workpiece W farthest from the pressing point PP (the nearer portion) to descend before the pressed portion. In other words, the nearer portion may fall faster than the farther portion. In the temporary placement jig 14C shown in FIG. 13 (modification), a temporary placement section 33C is formed so that the inclination αC of the rod-shaped member 36C is greater than the inclination α shown in the third embodiment. This inclination αC is set so that even if the pressing point PP shifts slightly toward the far or near side in the depth direction, the fall position of the workpiece W shifts toward the far side. With this configuration, a gap is secured between the front plate 45 of the storage box 12 and the workpiece W, and the rear plate 44 of the storage box 12 can prevent the workpiece W from shifting excessively toward the far side.

[0069] In the above embodiments, the temporary placement portion 33 is formed by a pair of rod-shaped members 36, but the temporary placement portion 33 may be modified as follows.

[0070] For example, in the temporary placement jig 14D shown in FIG. 14(a), a pair of left and right flat plates 36D arranged with a gap 35D between them constitutes a temporary placement section 33D. Such a temporary placement jig 14D is preferable for preventing the temporarily placed workpiece W from sagging and preventing it from shifting position after temporary placement. Also, in the temporary placement jig 14E shown in FIG. 14(b), a single flat plate constitutes the temporary placement section 33E. An opening 38E is formed in the center of the temporary placement section 33E as a "passage section." For example, it is preferable to form the left and right edges 39E constituting the opening 38E so that the distance between the edges 39E is narrower at the rear side than at the front side.

[0071] It is also possible to provide a separate device for temporarily placing the workpiece W and a separate device for pressing the workpiece W. For example, a suction transport device capable of adsorbing the workpiece W may be used to transport the workpiece W from the conveyor 11 to the temporary placement jig 14, where it is temporarily placed, and a robot 13 may be used to press the workpiece W. Also, instead of the robot 13, a piston or a solenoid may be used to press the workpiece W. It is also possible for a person to perform either the temporary placement or pressing operation, and for the workpieces W to be stacked (packed in boxes) in cooperation with the robot 13.

[0072] The distance between the temporary placement section 33 and the bottom plate section 41 of the storage box 12 may be adjustable according to the number of stacked workpieces W. For example, a lifting mechanism may be provided that raises and lowers either the temporary placement section 33 or the storage box 12, and the temporary placement section 33 may be raised or the storage box 12 may be lowered to increase the distance between the temporary placement section 33 and the bottom plate section 41 according to an increase in the number of stacked workpieces W.

[0073] In the above embodiments, the laminating device 10 is applied to a boxing process of rubber sheets, but the application is not limited to this. The laminating device 10 can also be applied to a boxing process for packing objects (corresponding to "workpieces") such as vehicle floor mats, entrance mats, place mats, vibration-damping sheets for keyboards, mouse pads, etc., or to a laminating process for stacking the objects on pallets, tables, etc.

[0074] <Inventions extracted from the above embodiments> The following describes the features of the inventions extracted from the above embodiments, while indicating, as necessary, their effects, etc. Note that, for ease of understanding, the corresponding configurations in the above embodiments are indicated in parentheses as appropriate, but the invention is not limited to the specific configurations indicated in parentheses.

[0075] Feature 1: A stacking device (stacking device 10) that stacks a plurality of flexible sheet-like workpieces (workpieces W) on a predetermined placement portion (bottom plate portion 41 of storage box 12), A jig (a temporary placement portion 33 of the temporary placement jig 14) is provided above the predetermined placement portion and on which the work is temporarily placed, The jig has a passage (gap 35) through which the work can pass when it falls onto the predetermined placement portion, A stacking device that temporarily places the work on the jig so that it covers at least a portion of the passing section, and drops the work through the passing section onto the specified loading section by pressing the portion of the temporarily placed work that covers the passing section from above.

[0076] After temporarily placing a workpiece on a jig positioned above a predetermined placement unit, the portion of the workpiece covering the jig's passage is pressed from above. As a result, the workpiece falls through the passage and onto the predetermined placement unit. This configuration allows the workpieces to be aligned before they begin to fall, reducing variations in their postures at the time they begin to fall compared to a configuration in which the workpieces are directly introduced from a conveyor or other transport device. Furthermore, each workpiece is pressed and deforms in the same manner as it passes through the passage, thereby preventing the workpieces from deforming into various patterns, at least while passing through the passage. This suppresses the workpieces from losing their posture during the fall, making it easier to control the way they fall when flexible sheet-like workpieces are being stacked. Furthermore, even if the operating speed of the device (e.g., the pressing speed) fluctuates, this is unlikely to affect the posture of the workpieces as they fall. For these reasons, a configuration can be realized that reduces the chances of workpieces being stacked in a bent state and allows for proper stacking of workpieces.

[0077] Feature 2: A stacking device according to Feature 1, in which a portion of a workpiece temporarily placed on the jig that covers the passing section is pressed from above to bend the workpiece so that it is convex downward, and the workpiece is dropped while remaining in the bent state at least while passing through the passing section.

[0078] If the workpiece is in a curved state, even if the workpiece further deforms, a certain tendency will emerge, thereby suppressing the diversification of the above-mentioned patterns. Furthermore, if the workpiece is curved so that it is convex downward, the drop posture will be less variable. Furthermore, deliberately designing the workpiece so that its corners are less likely to collide with the designated placement surface before dropping it has the technical significance of reducing the chance of the corners hitting the designated placement surface first, resulting in the aforementioned bending. Furthermore, even if the workpiece collides with the designated placement surface while still convex downward, it is expected that the workpiece will return to a flat state due to its own weight. In other words, even if a configuration is adopted that actively curves the workpiece, it is possible to avoid the increased effort required to return the workpiece to a flat state.

[0079] Feature 3: The jig has a pair of opposing portions (rod-shaped members 36) arranged side by side and facing each other with a gap therebetween, The gap serves as the passage portion, the gap gradually increases from one end to the other end in a direction perpendicular to the arrangement direction of the opposing portions when viewed from above, 3. The stacking device according to Feature 1 or Feature 2, wherein, while the workpiece is temporarily placed on the jig, the workpiece is dropped through the passing section by pressing a portion of the workpiece that is close to the one end.

[0080] For example, assuming that the gap (passage) between the opposing parts is constant in width, the workpiece's descent tends to be delayed in areas farther from the pressing position. Here, if the workpiece is pressed against the center in a direction perpendicular to the arrangement of the opposing parts as viewed from above, even a slight deviation in the perpendicular direction will cause the workpiece to rotate (tilt) due to the delay, resulting in a deviation in the workpiece's fall position in the direction opposite to the deviation in the pressing position. This can hinder the workpiece from being stacked straight. While offsetting the pressing position makes it easier to align the direction in which the fall position deviates, it also increases the possibility of the workpiece rotating significantly and tilting excessively. This raises concerns that this could lead to the bending described in Feature 1, etc.

[0081] In this respect, in the configuration shown in this feature, the width of the gap (passage portion) gradually increases from one end to the other end in the orthogonal direction, pressing the portion of the workpiece closer to the one end. This allows the workpiece to descend faster at the other end where the width is wider. In other words, it can act to counteract the effects of the biased pressing position. This allows the effects of the biased pressing position to be enjoyed while suppressing the resulting inconvenience.

[0082] Feature 4: The jig has a pair of opposing portions (rod-shaped members 36) arranged side by side and facing each other with a gap therebetween, The gap serves as the passage portion, A stacking device according to Feature 1, in which a portion of a workpiece temporarily placed on the jig that covers the passing section is pressed from above at the center of the passing section in the arrangement direction of the opposing sections, causing the workpiece to bend so as to be convex downward, and the workpiece is dropped while remaining in the bent state at least while passing through the passing section.

[0083] As shown in this feature, by pressing the workpiece at the center of the passage in the direction of the arrangement of the opposing parts, the pressing force required to bend the workpiece so that it is convex downward can be minimized. This is preferable for protecting the workpiece. Furthermore, if a difference in resistance (frictional resistance) occurs between the contact points between the two opposing parts and the workpiece when bending the workpiece so that it is convex downward, there is a high possibility that the position of the workpiece will shift in the above-mentioned direction when bending the workpiece. Pressing the workpiece at the above-mentioned position is also preferable to reduce the likelihood of such an occurrence.

[0084] Feature 5: The jig has a pair of opposing portions (rod-shaped members 36) arranged side by side and facing each other with a gap therebetween, The gap serves as the passage portion, The workpieces are temporarily placed so that they each protrude from the opposing portions on the side opposite to the passing portion side, and the amount of protrusion of the workpiece on one opposing portion side is smaller than the amount of protrusion of the workpiece on the other opposing portion side; A stacking device according to Feature 1, in which the part of the workpiece temporarily placed on the jig that covers the passing section is pressed from above at a position biased toward one of the opposing sections, causing the workpiece to drop through the passing section onto the predetermined loading section.

[0085] According to this characteristic configuration, when the workpiece is pressed, it is released from its engagement with one of the opposing portions, tilting the workpiece so that the other opposing portion is on top and one opposing portion is on the bottom. Furthermore, since the workpiece remains resting on the other opposing portion, it slides down along the opposing portion. This configuration makes it easier to control the falling posture of the workpiece at least until the entire workpiece passes through the passage. In other words, this contributes to suppressing the bending caused by disturbances in the falling posture.

[0086] Feature 6: The robot 13 includes a pressing unit (hand 24) that can be raised and lowered and that presses from above a portion of the workpiece temporarily placed on the temporary placement unit that covers the passage unit, thereby causing the workpiece to drop through the passage unit onto the predetermined placement unit. 6. The stacking device according to any one of features 1 to 5, wherein the pressing unit is lowered to a predetermined lowered position (lowered position P4) to press the workpiece, and then immediately rises.

[0087] In a configuration in which the workpiece is bent by the pressing portion, it is expected that the falling posture of the workpiece will be easily disturbed if the bent workpiece comes into contact with the pressing portion from the side (for example, by pinching the pressing portion). Therefore, as shown in this feature, by configuring the pressing portion to immediately rise when it reaches a predetermined lowered position, and by configuring the pressing portion to suppress interference between the pressing portion and the workpiece after pressing, it is possible to suppress the occurrence of the above-mentioned inconvenience.

[0088] Feature 7. The stacking system according to Feature 6, wherein the predetermined lowering position is configured to be below the passing section.

[0089] To quickly drop a workpiece temporarily placed on a jig, it is preferable to have a configuration in which the workpiece is pushed to a predetermined drop position set below the passage section rather than relying on the workpiece's own weight. However, such a configuration is prone to the above-mentioned interference. Therefore, by applying the technical idea described in Feature 4 to this configuration, the pressing section is immediately raised after the workpiece reaches the predetermined drop position, thereby realizing a configuration in which the workpiece is quickly dropped while suppressing disturbance in the workpiece's drop posture.

[0090] Feature 8: The stacking device according to any one of Features 1 to 7, wherein the distance between the placement section and the jig is changeable.

[0091] As the number of workpieces stacked increases, the difference between the maximum and minimum drop distances of the workpieces increases. In other words, the difference in drop distance between dropping the first workpiece onto the mounting section and dropping another workpiece onto a stack of workpieces becomes significant. If the difference in drop distance becomes too large, there is a concern that the control of the workpiece drop posture will not function properly. In this regard, as shown in this feature, if the distance between the mounting section and the jig (opposing section) can be changed, the drop distance can be adjusted appropriately depending on the situation. This will alleviate the above concerns. For example, it is recommended to configure the opposing section to be raised and lowered, or to configure the mounting section to be raised and lowered.

[0092] Feature 9: The placement portion is a bottom portion (bottom plate portion 41) of a storage box (storage box 12) capable of storing a plurality of the works, The jig is positioned above the upper opening (opening 46) of the storage box, 9. The stacking device according to any one of features 1 to 8, wherein the workpieces are packed into the container box so as to be stacked on the bottom.

[0093] When packing (stacking) workpieces into boxes using a stacking device, it is undesirable for the stacking device (e.g., a robot) to come into contact with the storage box in order to avoid misalignment or damage to the storage box and to protect the stacking device. In this regard, if the workpieces temporarily placed above the upper opening (feed port) of the storage box are dropped into the storage box, the workpieces can be stacked properly without having to lower the stacking device to near the bottom of the storage box. Therefore, the main operating area of ​​the stacking device can be set outside the storage box. This is preferable in terms of reducing the chance of contact between the stacking device and the storage box.

[0094] Feature 10: A stacking device (stacking device 10) that stacks multiple flexible sheet-like workpieces (workpieces W) on a predetermined placement portion (bottom plate portion 41 of storage box 12), A jig (a temporary placement portion 33 of the temporary placement jig 14) is provided above the predetermined placement portion and capable of temporarily placing the workpiece, The jig has a passage (gap 35) through which the work can pass when it falls onto the predetermined placement portion, The workpiece is temporarily placed on the jig so as to cover a portion of the passing section, and when the workpiece temporarily placed on the jig passes through the passing section and falls onto the designated placement section, the jig abuts against the workpiece in at least the section of the workpiece's falling path up to the point where the workpiece passes through the passing section, thereby controlling the falling posture of the workpiece to a predetermined posture (for example, a curved posture that is convex downward or a posture that is inclined to one side).

[0095] By temporarily placing the workpieces on a jig positioned above a predetermined placement section, it is possible to align the workpieces before they begin to fall. This reduces the variation in the workpieces' postures at the time they begin to fall, compared to a configuration in which the workpieces are directly loaded from a transport device such as a conveyor. Furthermore, the falling posture of the workpieces is controlled to be a predetermined posture at least in the section passing through the passing section. This makes it easier to control the falling behavior of flexible sheet-like workpieces, suppressing the disruption of the workpieces' postures during the fall. Therefore, it is possible to reduce the chances of workpieces being stacked while still bent, and realize a configuration that allows the workpieces to be stacked properly. Note that the technical concepts described in Features 1 to 9 may also be applied to this feature.

[0096] Feature 11: An industrial robot (robot 13) is provided with a gripping unit (hand 24) that grips the workpiece at the tip (tip 23) of an arm (arm 22), The stacking device described in Features 1 to 10, wherein the industrial robot temporarily places the workpiece held by the gripping portion on the jig, and after releasing the workpiece temporarily placed on the jig, presses the portion of the workpiece covering the passing portion from above with the tip portion, thereby dropping the workpiece through the passing portion onto the predetermined loading portion.

[0097] By using a gripper provided on the arm (tip) of an industrial robot to temporarily place a workpiece on a jig and then pressing the workpiece with the tip of the arm, a series of operations can be performed without changing tools, etc. This is preferable for improving the efficiency of stacking operations. Note that the workpiece may be pressed by the gripper, or may be pressed by a part of the tip other than the gripper. Incidentally, the technical ideas shown in Features 1 to 10 may also be applied to this feature.

[0098] Feature 12. The gripping portion is configured to sandwich the end of the workpiece from above and below when the workpiece is temporarily placed on the jig, and when the gripping portion is oriented in a direction that allows it to sandwich the end of the workpiece, a part of the tip of the arm protrudes below the gripping portion, A stacking device as described in Feature 11, which performs a moving operation in which the tip of the arm moves above the workpiece and a pressing operation in which the part of the tip pushes the workpiece from above while maintaining the orientation of the gripping portion when the workpiece is temporarily placed on the jig.

[0099] This feature of the configuration allows temporary placement and pressing without changing the orientation of the gripper. This simplifies the movement of the industrial robot. Furthermore, pressing is performed using a part of the tip (a part other than the gripper) rather than the gripper. This is preferable in terms of protecting both the gripper and the workpiece.

[0100] Feature 13: An industrial robot (stacking device 10) that stacks a plurality of flexible sheet-like workpieces (workpieces W) on a predetermined placement portion (bottom plate portion 41 of storage box 12), The work is temporarily placed on a jig (temporary placement portion 33 of temporary placement jig 14) that is located above the predetermined placement portion and has a passage portion (gap 35) through which the work can pass when dropping to the predetermined placement portion, so as to cover at least a part of the passage portion; After the temporary placement of the workpiece is completed, the industrial robot drops the workpiece through the passing section onto the designated placement section by pressing from above on the part of the temporarily placed workpiece that covers the passing section.

[0101] According to the industrial robot of this feature, the chances of workpieces being stacked in a bent state can be reduced, and the workpieces can be stacked properly. Note that the technical ideas of Features 1 to 12 may also be applied to this feature.

[0102] Feature 14. A robot control program applied to an industrial robot (robot 13) for controlling the industrial robot to stack a plurality of flexible sheet-like workpieces (workpieces W) on a predetermined placement portion (bottom plate portion 41 of storage box 12), The control device (controller 25) of the industrial robot includes: a process of causing the industrial robot to execute an operation of temporarily placing the work on a jig (temporary placement portion 33 of temporary placement jig 14) that is positioned above the predetermined placement portion and has a passage portion (gap 35) formed therein through which the work can pass when dropping to the predetermined placement portion, so as to cover at least a part of the passage portion; a process of causing the industrial robot to perform a pressing operation to drop the workpiece onto the predetermined placement part through the passing part by pressing from above a part of the workpiece temporarily placed on the jig that covers the passing part; A robot control program that executes the above.

[0103] By controlling an industrial robot using the robot control program described in this feature, the chances of workpieces being stacked in a bent state can be reduced, and the workpieces can be stacked properly. Note that the technical ideas described in Features 1 to 13 may also be applied to this feature.

[0104] Feature 15. A stacking method for stacking a plurality of flexible sheet-like workpieces (workpieces W) on a predetermined placement portion (bottom plate portion 41 of storage box 12), a temporary placement process in which the workpiece is temporarily placed on a jig (temporary placement portion 33 of temporary placement jig 14) that is located above the predetermined placement portion and has a passage portion (gap 35) through which the workpiece can pass, so as to cover at least a part of the passage portion; a pressing step in which, after the temporary placement of the workpiece is completed, a portion of the temporarily placed workpiece that covers the passing section is pressed from above, thereby causing the workpiece to drop onto the predetermined placing section through the passing section; The lamination method comprising:

[0105] According to the stacking method described in this feature, the chances of stacking workpieces in a bent state can be reduced, and the workpieces can be stacked properly. Note that the technical ideas described in Features 1 to 14 may also be applied to this feature. [Explanation of symbols]

[0106] 10...stacking device, 12...storage box, 13...robot, 14...temporary placement jig, 22...arm, 24...hand, 25...controller, 33...temporary placement section, 35...gap, 36...rod-shaped member, 41...bottom, 46...opening, W...workpiece, P4...lowering position, PP...pressing point.

Claims

1. A stacking device that stacks a plurality of flexible sheet-like workpieces on a predetermined placing portion, a jig disposed above the predetermined placement portion and on which the workpiece is temporarily placed; The jig is formed with a passage through which the work can pass when it falls onto the predetermined placement portion, The workpiece is temporarily placed on the jig so as to cover at least a portion of the passing section, and the portion of the temporarily placed workpiece that covers the passing section is pressed from above, thereby causing the workpiece to drop onto the predetermined placement section through the passing section; The jig has a pair of opposing portions that are arranged side by side and opposed to each other with a gap therebetween, The gap serves as the passage portion, the gap gradually increases from one end to the other end in a direction perpendicular to the arrangement direction of the opposing portions when viewed from above, A stacking device that, while the workpiece is temporarily placed on the jig, drops the workpiece through the passage by pressing a portion of the workpiece that is close to the one end.

2. A stacking device that stacks a plurality of flexible sheet-like workpieces on a predetermined placing portion, a jig disposed above the predetermined placement portion and on which the workpiece is temporarily placed; The jig is formed with a passage through which the work can pass when it falls onto the predetermined placement portion, The workpiece is temporarily placed on the jig so as to cover at least a portion of the passing section, and the portion of the temporarily placed workpiece that covers the passing section is pressed from above, thereby causing the workpiece to drop onto the predetermined placement section through the passing section; The jig has a pair of opposing portions that are arranged side by side and opposed to each other with a gap therebetween, The gap serves as the passage portion, The workpieces are temporarily placed so that they each protrude from the opposing portions on the side opposite to the passing portion side, and the amount of protrusion of the workpiece on one opposing portion side is smaller than the amount of protrusion of the workpiece on the other opposing portion side; A stacking device that drops a workpiece temporarily placed on the jig through the passing section onto the designated loading section by pressing the part of the workpiece covering the passing section from above at a position biased toward one of the opposing sections.

3. A stacking device that stacks a plurality of flexible sheet-like workpieces on a predetermined placing portion, a jig disposed above the predetermined placement portion and on which the workpiece is temporarily placed; The jig is formed with a passage through which the work can pass when it falls onto the predetermined placement portion, The workpiece is temporarily placed on the jig so as to cover at least a portion of the passing section, and the portion of the temporarily placed workpiece that covers the passing section is pressed from above, thereby causing the workpiece to drop onto the predetermined placement section through the passing section; The jig has a pair of opposing portions arranged side by side and facing each other with a certain gap between them, The fixed gap serves as the passage portion, The pair of opposing portions are attached to supports with the fixed gap therebetween.

4. A stacking method for stacking a plurality of flexible sheet-like workpieces on a predetermined placing portion, comprising: a temporary placement process of temporarily placing the work on a jig that is located above the predetermined placement portion and has a passage through which the work can pass, so as to cover at least a part of the passage; a pressing step in which, after the temporary placement of the workpiece is completed, a portion of the temporarily placed workpiece that covers the passing section is pressed from above, thereby causing the workpiece to drop onto the predetermined placing section through the passing section; The lamination method comprising:

Images