Workpiece stacking device and workpiece stacking method

Abstract

To provide a technique for securely inverting and sequentially stacking a part of the workpieces.SOLUTION: A workpiece stacking device is for stacking a workpiece W2 on a workpiece W1 and includes: a first acquisition / reversal mechanism 120 for acquiring the workpiece W2 from one surface side of the workpiece; a second acquisition / reversal mechanism 130 for acquiring the workpiece W2, which has been acquired by the first acquisition / reversal mechanism 120, from the other surface side of the workpiece and for releasing the one surface of the workpiece; and a moving part for moving the second acquisition / reversal mechanism 130 to position the workpiece W2, which has been acquired by the second acquisition / reversal mechanism 130, such that the one surface of the workpiece faces the workpiece W1. The second acquisition / reversal mechanism 130 releases the workpiece W2 when it is positioned above the workpiece W1, thereby stacking the workpiece W2 on the workpiece W1.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] Embodiments of the present invention relate to a technique for overlapping at least two workpieces with each other.

Background Art

[0002] Conventionally, as this type of apparatus, a workpiece stacking apparatus described in Patent Document 1 below is known. This apparatus arranges and erects a pair of receiving columns spaced at an interval corresponding to the width of the workpiece and a minimum number of rear columns on a base so as to form a space conforming to the shape of the workpiece surrounded by each column, and provides workpiece support portions for supporting the workpiece at predetermined height positions of each column. The workpiece support portion is composed of a workpiece support piece rotatably provided with respect to the column and a stopper for horizontally supporting the workpiece support piece.

[0003] By the way, in factories or the like that mass-produce or process workpieces such as parts and products that need to overlap one surface (hereinafter referred to as the overlapping surface) with each other, each workpiece has the overlapping surface facing upward and is arranged, for example, alternately on a conveying device such as a conveyor and continuously conveyed. In such a case, it is necessary for a large number of workers to turn over the continuously conveyed workpieces as appropriate according to their own judgment and stack them sequentially. Such manual work, even when using the above-described workpiece stacking apparatus, results in high labor costs and may also cause mistakes such as overlapping not the overlapping surfaces but, for example, the upper surface and the back surface.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] The problem to be solved by the embodiments of the present invention is to provide a technique capable of reliably inverting some workpieces and stacking them sequentially.

Means for Solving the Problem

[0006] To solve the above-described problems, an embodiment of the present invention is a workpiece stacking device that stacks a second workpiece on a first workpiece, including: a first acquisition unit that acquires the second workpiece from one surface side of the workpiece; a second acquisition unit that acquires the second workpiece in the state acquired by the first acquisition unit from the other surface side of the workpiece and releases one surface of the workpiece; and a moving unit that moves the second acquisition unit to position the second workpiece in the state acquired by the second acquisition unit such that one surface of the workpiece faces the first workpiece. The second acquisition unit releases the second workpiece when the second workpiece is positioned on the first workpiece, and stacks the second workpiece on the first workpiece.

Effects of the Invention

[0007] According to the embodiments of the present invention, it is possible to provide a technique capable of reliably inverting some workpieces and stacking them sequentially.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

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Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

MODE FOR CARRYING OUT THE INVENTION

[0009] <First Embodiment> Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the present specification and drawings, components having substantially the same functional configuration are denoted by the same reference numerals, and redundant description is omitted.

[0010] (Device Configuration) FIG. 1 is a schematic perspective view showing the work stacking system according to the present embodiment. As shown in FIG. 1, the work stacking system 1 according to the present embodiment includes a stacking inversion device 10, an upstream transfer conveyor 20, a downstream transfer conveyor 30, a moving device 40, a sensor 50, and a control device 60 (see FIG. 4) not shown here. The reference sign X shown in FIG. 1 indicates the transfer direction of the upstream transfer conveyor 20 and the downstream transfer conveyor 30.

[0011] The stacking and inverting device 10 acquires the sheet-like workpieces W1 and W2 positioned on the upstream conveying conveyor 20, and manufactures a stacked workpiece W3 by sequentially stacking these on top of each other and placing them on the downstream conveying conveyor 30. At this time, the stacking and inverting device 10 inverts the workpiece W2 and stacks it on the workpiece W1. Specifically, the workpiece W1 is positioned below, and the workpiece W2 is stacked thereon such that their upper surfaces, which are the stacking surfaces, face each other. Here, the upper surface refers to the surface facing upward during conveyance. The detailed configuration of the stacking and inverting device 10 will be described later.

[0012] Note that examples of the stacked workpiece W3 composed of such two sheet-like workpieces W1 and W2 include a low-frequency pad. The low-frequency pad has a plurality of terminals, also called conductors, arranged between two pads (workpieces) of the same shape forming a sheet, or at least on one of the pads. A pulsed-wave current from a device that generates a pulsed wave flows between these terminals to apply a useful low-frequency wave to the human body. In the present embodiment, terminals are provided on both the workpiece W1 and the workpiece W2. Therefore, the workpiece W1 and the workpiece W2 will be described as being the same hereafter.

[0013] The upstream conveying conveyor 20 is positioned upstream of the stacking and inverting device 10 in the conveying direction X, and conveys the workpiece W1 received from an inspection machine (not shown) positioned upstream thereof to below the stacking and inverting device 10 positioned downstream. On the other hand, the downstream conveying conveyor 30 is positioned downstream of the stacking and inverting device 10 in the conveying direction X, and conveys the stacked workpiece W3 placed and manufactured by the stacking and inverting device 10 downstream, for example, to a packaging machine that packages the stacked workpiece W3.

[0014] Each of the upstream and downstream conveying conveyors 20 and 30 is supported by a plurality of legs 22 and 32 and is disposed in the working area of the stacking and inverting device 10. Each of the upstream and downstream conveying conveyors 20 and 30 has a belt such as an endless timing belt extending in the conveying direction X, and the belt is wound around a driving roller (not shown) and is thereby circulated to convey the workpieces W1 to W3 on the belt. The driving roller is rotationally driven by a rotational driving device 210, 310 (see FIG. 4), such as a motor, not shown in FIG. 1. The driving timing, speed, etc. of the rotational driving device are controlled by the control device 60 based on the output of an instrument such as an encoder provided in the rotational driving device.

[0015] The moving device 40 includes a movable support portion 42 that supports the stacking and inverting device 10 so as to be vertically movable, a first rotation support portion 44 that rotatably supports the movable support portion 42, a second rotation support portion 46 that rotatably supports the first rotation support portion 44, and a base 48 that is connected to the lower portion of the second rotation support portion 46 and is formed in a vertically long shape to support the second rotation support portion 46 immovably.

[0016] The movable support portion 42 is disposed above the stacking and inverting device 10. The movable support portion 42 incorporates an arbitrary actuator such as a hydraulic or pneumatic piston cylinder or solenoid (not shown), and a connecting member 422 that can be vertically moved by the actuator is connected to the stacking and inverting device 10 to support the stacking and inverting device 10 so as to be vertically movable. It is preferable that the connecting member 422 is rotatable around a rotation axis (not shown) using a rotation driving device different from the above-described actuator for vertical movement.

[0017] The first pivoting support portion 44 is disposed on the side of the movable support portion 42 away from the stacking and inverting device 10 (hereinafter referred to as the rear) along the orthogonal direction orthogonal to the conveying direction X and the vertical direction. The first pivoting support portion 44 incorporates a rotational drive device (not shown) such as a motor, and a hollow cylindrical upper pivoting portion 442 and a lower pivoting portion 444 are rotatable around a pivoting axis (not shown) having the vertical direction as its axis by this device. Each of the upper pivoting portion 442 and the lower pivoting portion 444 is integrally and rotatably connected to the movable support portion 42. Therefore, the first pivoting support portion 44 rotatably supports the movable support portion 42 so as to swing it left and right around its pivoting axis.

[0018] The second pivoting support portion 46 is disposed behind the first pivoting support portion 44. The second pivoting support portion 46 incorporates a rotational drive device (not shown) such as a motor, and a hollow cylindrical pivoting portion 462 is rotatable around a pivoting axis (not shown) having the vertical direction as its axis by this device. The pivoting portion 462 is integrally and rotatably connected to the middle abdomen 446 between the upper pivoting portion 442 and the lower pivoting portion 444 of the first pivoting support portion 44 via a bridge 464. Therefore, the second pivoting support portion 46 rotatably supports the first pivoting support portion 44 so as to swing it left and right around its pivoting axis. Note that the bridge 464 preferably has an arbitrary actuator and is configured to be able to move the first pivoting support portion 44 forward and backward along the orthogonal direction.

[0019] With the movable support portion 42, the first and second pivoting support portions 44 and 46, the stacking and inverting device 10 has degrees of freedom in the conveying direction X, the orthogonal direction, and the vertical direction, enabling high-speed movement and high-precision positioning. The driving timings of various actuators such as the rotational drive devices incorporated in the movable support portion 42, the first and second pivoting support portions 44 and 46 are controlled by the control device 60. Note that instead of such a moving device 40, a robot arm or a multi-joint robot capable of high-speed movement and high-precision positioning, such as a parallel link robot composed of a link and a joint arm, may be used.

[0020] The sensor 50 is for detecting the positions of the workpieces W1 and W2, and the detection result is sent to the control device 60. The control device 60 acquires the detection result and drives and controls the stacking and inverting device 10 and the moving device 40. Examples of the sensor 50 include a camera. For example, the control device 60 performs image processing such as pattern matching, tilt correction, and binarization on the image captured by the camera to identify the position, and calculates the pickup position by the stacking and inverting device 10 based on the identified position and the conveying speed of the downstream conveying conveyor 30. The sensor 50 is not limited to a camera, and the position may be identified simply by a contact or non-contact sensor, and any sensor may be used as long as it can detect the positions of the workpieces W1 and W2.

[0021] (Configuration of the stacking and inverting device) Hereinafter, the specific configuration of the stacking and inverting device 10 will be described. FIGS. 2 and 3 are a schematic front view and a schematic side view showing the configuration of the stacking and inverting device according to the present embodiment. The front here refers to the stacking and inverting device as viewed from the front in the orthogonal direction, and the side refers to the stacking and inverting device as viewed from the conveying direction X. Note that FIGS. 2 and 3 show the stacking and inverting device 10 in the initial state.

[0022] As shown in FIGS. 2 and 3, the stacking and inverting device 10 has a base plate 101 that extends in the vertical direction and the conveying direction, with the lower part protruding forward and bending upward. An upper plate 102 that protrudes upward is provided at approximately the upper center of the base plate 101 in the conveying direction X, and two support shafts 103a and 103b that are arranged in parallel along the conveying direction X are non-rotatably connected to the upper plate 102.

[0023] Of the two support shafts 103a and 103b, the support shaft 103a located on the upstream side in the conveyance direction X rotatably supports the upper end of the long piston cylinder 104a. The piston cylinder 104a is inclined and arranged such that its lower end is located on the upstream side in the conveyance direction X from the upper end, and the piston rod is reciprocally accommodated along its axial direction by oil hydraulics or the like. Note that in FIG. 2, the state in which the piston rod is accommodated is shown. A support shaft 105 is rotatably inserted through the lower end of the piston rod. The support shaft 105 is inserted through a rotating member 106 extending in one direction. Specifically, in the initial state, the rotating member 106 has a Y-shaped posture when viewed from the front, and one end (the upper end in FIG. 2) has an angle of approximately 90 degrees and bifurcates and extends. The support shaft 105 is inserted through one of the two extending portions on the downstream side in the conveyance direction X of the bifurcated rotating member 106.

[0024] The support shaft 107 is rotatably inserted through the rotating member 106 near the confluence position of the two bifurcated extending portions. The support shaft 107 is non-rotatably supported by a rectangular intermediate plate 108 connected to a bent portion formed in the lower part of the base plate 101. Thus, when the piston rod advances downward due to the piston cylinder 104a, one extending portion of the rotating member 106 is pressed downward to the right in FIG. 2, and due to this pressing, the rotating member 106 can rotate clockwise in FIG. 2 about the support shaft 107.

[0025] At the other end of the rotating member 106 (the lower end in FIG. 2), a suction transfer portion 109 is attached. The suction transfer portion 109 has an arbitrary actuator such as a pneumatic / hydraulic piston cylinder or a solenoid (not shown) and two suction pads 110 arranged in parallel in the orthogonal direction. The actuator supports the rod 111 so that it can move forward and backward along one direction. The rod 111 has a rectangular support plate 112 connected to one end on the lower side, and two suction pads 110 are provided on the lower surface of the support plate 112. In FIGS. 2 and 3, for the sake of explanation, a state is shown in which the rod 111 extends downward and moves the suction pads 110 downward via the support plate 112. The suction pads 110 adsorb (acquire) the workpieces W1, W2 by evacuating the air between the suction pads 110 and the workpieces W1, W2 by evacuation by a vacuum pump 140 (see FIG. 4, not shown) in a state where the suction pads 110 are in contact with the workpieces W1, W2. When the evacuation by the vacuum pump 140 is released, the suction pads 110 release the adsorbed workpieces W1, W2.

[0026] The reference numeral 120 shown in FIG. 2 indicates a first acquisition and inversion mechanism composed of the components described above with reference numerals 104a, 105 to 112 attached.

[0027] Of the two support shafts 103a and 103b, the support shaft 103b located on the downstream side in the conveying direction X rotatably supports the upper end of the long piston cylinder 104b. The piston cylinder 104b is inclined and arranged such that its lower end is located on the downstream side in the conveying direction X than the upper end, and the piston rod is accommodated to be reciprocable along its axial direction by oil-hydraulic pressure or the like. In FIG. 2, the state where the piston rod has advanced, that is, has moved forward downward, is shown. A support shaft 125 is rotatably inserted through the lower end of the piston rod. The support shaft 125 is inserted through the rotating member 126. Specifically, in the initial state, the rotating member 126 has a substantially L-shaped posture when viewed from the front, one extending upstream in the conveying direction X, and the other having an angle of approximately 90 degrees around a support shaft 127 to be described later with respect to the one and extending downward. Hereinafter, these extending portions are referred to as long extending portions. Further, on the rotating member 126, short extending portions are formed which have an angle of 135 degrees around the support shaft 127 with respect to each long extending portion and extend short from the confluence portion of the long extending portions. The support shaft 125 is inserted through the end of the short extending portion.

[0028] Also, a support shaft 127 is rotatably inserted through the confluence portion of the long extending portions in the rotating member 126, which is located on the upstream side in the conveying direction X from the insertion portion of the support shaft 125. The support shaft 127 is supported by a rectangular intermediate plate 128 connected to a bent portion formed in the lower part of the base plate 101. Thereby, when the piston rod is retracted upward by the piston cylinder 104b, the short extending portion of the rotating member 126 is pulled upward to the right in FIG. 2, and due to this pulling, the rotating member 126 can rotate clockwise in FIG. 2 around the support shaft 127.

[0029] First and second adsorption release portions 129a and 129b are individually attached to the ends of the two long extending portions in the rotating member 126. The first and second adsorption release portions 129a and 129b each have a rectangular support plate 112 connected to the end of the long extending portion and two adsorption pads 110 provided on the lower surface of the support plate 112.

[0030] Reference numeral 130 shown in FIG. 2 indicates a second acquisition inversion mechanism composed of the respective components described above with reference numerals 104b, 110, 112, 125 to 128, 129a, and 129b attached thereto.

[0031] Incidentally, the six suction pads 110 may be configured such that they can be fluidly connected to and disconnected from each other as appropriate by a solenoid valve or the like whose flow path communicating the respective suction pads 110 and the vacuum pump 140 can be controlled by the control device 60 so that the work can be sucked by one vacuum pump 140. Alternatively, a vacuum pump 140 may be provided for each suction pad 110.

[0032] (Control device 60) FIG. 4 is a block diagram showing the control system of the work stacking system according to the present embodiment. The control device 60 is configured as an information processing device having a CPU (Central Processing Unit), a RAM (Random Access Memory), and a storage device such as a flash memory and operable by an operator. As shown in FIG. 4, the control device 60 has the CPU and the RAM cooperate to drive and control a drive device group 150 including the vacuum pump 140 of the stacking inversion device 10 and various actuators (not shown), and also drive and control a drive device group 410 including various actuators (not shown) and a rotation drive device of the moving device 40. At that time, the control device 60 adjusts the drive timing, particularly the pickup timing of the works W1 and W2, based on the detection result from the sensor 50. Further, the rotation drive devices 210 and 310 of the upstream and downstream transfer conveyors 20 and 30 are driven and controlled based on the detection result from their encoders. The control device 60 has a control panel (not shown), and the operator can turn on / off the above-described respective devices and change various settings by operating the control panel. Examples of the settings here include the transfer speed of each conveyor, the image processing method, the drive timing of each drive device, and the increase or decrease in the number of stacked works.

[0033] Note that as the control device 60, a PC (Personal Computer) or a server may be used. If various devices are configured to be wirelessly communicable and an interface capable of wireless communication with these devices is incorporated, a tablet terminal such as a smartphone may also be used. Further, it is also possible to operate the work stacking system 1 from a remote location. In that case, communication may be performed with the control device 60 via a network such as the Internet from a tablet terminal at the remote location, and the work stacking system 1 may be made controllable. In this case, the control device 60 may be constructed as a cloud server.

[0034] (Device operation) Next, the operation of the work stacking system 1 will be described. FIGS. 5 to 9 are diagrams for explaining the operation of the work stacking system according to the present embodiment. In FIGS. 5 to 10, the main part of the work stacking system 1 as viewed from the front is shown. Note that at the start of operation of the work stacking system 1, the stacking inversion device 10 is in an initial state.

[0035] First, the upstream and downstream transfer conveyors 20 and 30 are driven, and the workpieces W1 and W2 are sequentially and alternately arranged along the transfer direction X and transferred on the upstream transfer conveyor 20. At this time, in the present embodiment, since the workpiece W2 is stacked on the workpiece W1, it is transferred in a state of being at the head of the workpiece group on which the workpiece W2 is transferred. Note that it is preferable to continuously transfer the workpieces W1, W2, and the stacked workpiece W3 at a constant speed even during the operation of each stacking inversion device 10 described later, from the viewpoint of improving the manufacturing speed of the stacked workpiece W3.

[0036] After conveyance, as shown in FIG. 5, the moving device 40 horizontally moves the stacking and inverting device 10 so that the suction pad 110 of the suction delivery unit 109 positioned downward as the initial state is positioned above the workpiece W2 placed on the upstream conveyance conveyor 20. After the horizontal movement, the stacking and inverting device 10 is moved downward so that the suction pad 110 abuts on the upper surface of the workpiece W2. After the abutment, the vacuum pump 140 is operated to suck the workpiece W2 to the suction pad 110. Here, the suction pad 110 of the suction delivery unit 109 is brought into contact with the upper surface of the workpiece W2 by moving the stacking and inverting device 10 downward only by the moving device 40. However, the contact may be realized by advancing the rod 111 downward by the actuator of the suction delivery unit 109.

[0037] After the workpiece W2 is sucked, as shown in FIG. 6, the moving device 40 horizontally moves the stacking and inverting device 10 so that the suction pad 110 of the first suction release unit 129a positioned downward as the initial state is positioned above the workpiece W1 placed on the upstream conveyance conveyor 20. After the horizontal movement, the stacking and inverting device 10 is moved downward so that the suction pad 110 abuts on the upper surface of the workpiece W1. After the abutment, the workpiece W1 is sucked to the suction pad 110 by the vacuum pump 140.

[0038] At this time, in parallel with the suction of the workpiece W1 in the above series of operations, the piston rod of the piston cylinder 104a advances downward, and the rotating member 106 is rotated 90 degrees clockwise in a front view. Due to the rotation, the suction pad 110 of the suction delivery unit 109 faces the suction pad 110 of the second suction release unit 129b with the sucked workpiece W2 in between.

[0039] Thereafter, as shown in FIG. 7, the stacking and inverting device 10 is horizontally moved by the moving device 40 so that the work W1 adsorbed by the adsorption pad 110 of the first adsorption and release unit 129a is positioned on the downstream transfer conveyor 30. After the horizontal movement, the stacking and inverting device 10 is moved downward so that the work W1 abuts or approaches the upper surface (placement surface) of the downstream transfer conveyor 30. Thereafter, the vacuum suction by the vacuum pump 140 acting on the adsorption pad 110 of the first adsorption and release unit 129a is blocked, and the inside of the pad is opened to the atmosphere, whereby the adsorption pad 110 releases the work W1.

[0040] At this time, in parallel with the release of the above-described series of work W1, the rod 111 advances toward the second adsorption and release unit 129b by the actuator of the adsorption transfer unit 109. Due to this advancement, the lower surface of the work W2 adsorbed by the adsorption pad 110 of the adsorption transfer unit 109 abuts against the adsorption pad 110 of the second adsorption and release unit 129b. In this state, the work W2 is adsorbed to the adsorption pad 110 of the second adsorption and release unit 129b by the vacuum pump 140. In synchronization with the adsorption, the vacuum suction by the vacuum pump 140 acting on the adsorption pad 110 of the adsorption transfer unit 109 is blocked, and the inside of the pad is opened to the atmosphere, whereby the adsorption pad 110 releases the work W2. In other words, the upper surface of the work W2 is released from the adsorption pad 110 of the adsorption transfer unit 109.

[0041] Thereafter, as shown in FIG. 8, the piston rod of the piston cylinder 104b is retracted upward, and the rotating member 126 is rotated 90 degrees clockwise in a front view. By this rotation, the adsorption pad 110 of the second adsorption and release unit 129b comes to be positioned above the work W1. At this time, in parallel with the above-described series of rotations of the second adsorption and release unit 129b, the adsorption pad 110 is retracted together with the rod 111 by the actuator of the adsorption transfer unit 109.

[0042] Thereafter, as shown in FIG. 9, as the stacking and inverting device 10 is moved downward, the workpiece W2 adsorbed by the suction pad 110 of the second suction release unit 129b comes into contact with or approaches the upper surface of the workpiece W1. Thereafter, the vacuum suction by the vacuum pump 140 acting on the suction pad 110 of the second suction release unit 129b is cut off, and the inside of the pad is opened to the atmosphere, so that the suction pad 110 releases the workpiece W2. By this release, the upper surface of the workpiece W1 and the upper surface of the workpiece W2 are opposed to each other and overlapped, in other words, the workpiece W2 can be inverted and overlapped with respect to the workpiece W1, and the stacked workpiece W3 can be manufactured.

[0043] At this time, in parallel with the production of the above series of stacked workpieces W3, the piston rod of the piston cylinder 104a is retracted upward, and the rotating member 106 is rotated 90 degrees counterclockwise in a front view. By this rotation, only the first acquisition and inversion mechanism 120 returns to the initial posture.

[0044] Thereafter, as shown in FIG. 10, the stacking and inverting device 10 is slightly moved upward and horizontally by the moving device 40 so that the suction pad 110 of the suction delivery unit 109 is positioned above the next workpiece W2 on the upstream conveying conveyor 20. At this time, in parallel with the above horizontal movement, the piston rod of the piston cylinder 104b is advanced downward, and the rotating member 106 is rotated 90 degrees counterclockwise in a front view. By this rotation, similarly to the first acquisition and inversion mechanism 120, the second acquisition and inversion mechanism 130 returns to the initial posture. Thereafter, the operations shown in FIGS. 5 to 10 are repeated. Further, the stacked workpiece W3 on the downstream conveying conveyor 30 is conveyed downstream by a certain amount of movement in preparation for the placement of the next workpiece W1.

[0045] According to the present embodiment described above, the workpiece W2 can be reliably and easily inverted and stacked on the workpiece W1. Further, such a system can also achieve cost reduction compared to the case of employing a large number of workers. Furthermore, since the two mechanisms of the first and second acquisition and inversion mechanisms 120 and 130 can operate in conjunction with each other, depending on the size of the workpieces W1 and W2, etc., it is possible to manufacture laminated workpieces W3 at about 60 to 70 pieces per minute, and the production efficiency can be improved at each stage.

[0046] In addition, in the embodiment described above, although it has been described that the rotating members 106 and 126 are rotated by a piston mechanism using piston cylinders 104a and 104b as actuators, the present invention is not limited thereto. For example, other reciprocating devices such as solenoids may be used. Further, for example, a rotary drive device such as a motor may be attached to the base plate 101, and the rotating members 106 and 126 may be rotated by the rotary drive device. Also, the piston cylinders 104a and 104b may be operated by commonly using the vacuum pump 140 for the suction pads 110 by providing a solenoid valve for the piston mechanism separately or the like.

[0047] <Second Embodiment> FIG. 11 is a schematic plan view schematically showing the configuration of a workpiece stacking system according to the present embodiment. As shown in FIG. 11, the workpiece stacking system 1A according to the present embodiment further includes a back surface inspection machine 70a, an upper surface inspection machine 70b, an inversion conveyor 80, surplus workpiece conveyance conveyors 90a and 90b, and surplus workpiece collection boxes 91a and 91b, and is different from the workpiece stacking system according to the first embodiment in that it includes a downstream conveyance conveyor 30a instead of the downstream conveyance conveyor 30.

[0048] Each of the back surface inspection machine 70a, the upper surface inspection machine 70b, and the inversion conveyor 80 is located on the upstream conveyance conveyor 20 and can be driven and controlled by the control device 60. In the present embodiment, the workpieces W1 and W2 conveyed by the upstream conveyance conveyor 20 are initially placed in a form in which the back surface (lower surface) uniformly faces upward. In FIG. 13, the hatched portion indicates the back surface.

[0049] The back surface inspection machine 70a non - contact inspects whether there are errors such as adhesion of impurities or chipping of the shape on the back surfaces of the workpieces W1 and W2. The top surface inspection machine 70b non - contact inspects whether there are errors such as adhesion of impurities or chipping of the shape on the top surfaces of the workpieces W1 and W2. These inspections can be realized, for example, by performing pattern matching or the like after imaging an image. The inversion conveyor 80 is incorporated as a part of the upstream conveyor 20, and pushes up from below to forwardly rotate the workpieces W1 and W2, thereby inverting the front and back of all of the workpieces W1 and W2 so that the top surfaces face upward.

[0050] Each of the surplus workpiece conveyors 90a and 90b is located on the front side of the stacking and inverting device 10 in the orthogonal direction, and discharges the workpieces W1 and W2 placed by the stacking and inverting device 10 individually into the corresponding surplus workpiece collection boxes 91a and 91b located further forward. For example, the surplus workpiece conveyor 90a has the workpiece W1 placed thereon, and the corresponding surplus workpiece collection box 91a collects it. On the other hand, the surplus workpiece conveyor 90b has the workpiece W2 placed thereon, and the corresponding surplus workpiece collection box 91b collects it.

[0051] The surplus workpiece conveyors 90a and 90b have a belt such as an endless timing belt extending in the orthogonal direction, and the belt is wound around a drive roller (not shown) and circulated thereby to convey the workpieces W1 and W2 on the belt. The drive roller is rotationally driven by a rotational drive device (not shown) such as a motor. The drive timing, speed, etc. of the rotational drive device are controlled by the control device 60 based on the output of an instrument such as an encoder provided in the rotational drive device.

[0052] The downstream conveyor 30a has a long table 34 extending in two conveying directions X spaced apart in the orthogonal direction, and a plurality of pushing members 36 are provided between them to push the stacked workpiece W3 along the conveying direction X in a circular motion along the conveying direction X. The plurality of pushing members 36 are provided on a belt such as an endless timing belt extending in the conveying direction X below the table 34, and the belt is wound around a driving roller (not shown) and thereby circulated to push the stacked workpiece W3 on the table 34 along the conveying direction X. The driving roller is rotationally driven by a rotational driving device (not shown) such as a motor. The driving timing, speed, etc. of the rotational driving device are controlled by the control device 60 based on the output of an instrument such as an encoder provided in the rotational driving device.

[0053] According to the present embodiment described above, the surfaces of the workpieces W1 and W2 can be inspected prior to stacking. Further, the workpiece determined to be an error based on the inspection result can be adsorbed by the stacking and inverting device 10 and discarded into an error product collection box (not shown). Furthermore, a workpiece that is supposed to be stacked on the discarded workpiece cannot be made into the stacked workpiece W3 even though it is a non-defective product. Therefore, it can be placed on either the surplus workpiece conveyors 90a and 90b according to its type by the stacking and inverting device 10 and recovered into either the surplus workpiece collection boxes 91a and 91b. The recovered surplus workpiece is preferably placed on the upstream conveyor 20 again. Also, according to the downstream conveyor 30a, the stacked workpiece W3 can be reliably conveyed in the same manner as the downstream conveyor 30.

[0054] In the present embodiment, the workpieces W1 and W2 have been described as being the same, but the present invention is not limited thereto. Needless to say, according to the present embodiment, workpieces having different configurations can be appropriately stacked.

[0055] The present invention can be implemented in various other forms without departing from its gist or main features. Therefore, the above-described embodiments are merely illustrative in every respect and should not be construed in a limiting sense. The scope of the present invention is indicated by the claims and is not restricted by the text of the specification. Further, all modifications, various improvements, alternatives, and modifications belonging to the equivalent scope of the claims are all within the scope of the present invention.

Explanation of Reference Numerals

[0056] 1 Work stacking system (work stacking device) 10 Stacking inversion device (work stacking device) 109 Adsorption transfer section (first acquisition section) 120 First acquisition inversion mechanism (first acquisition section) 129a First adsorption release section (third acquisition section) 129b Second adsorption release section (second acquisition section) 130 Second acquisition inversion mechanism (second acquisition section) 40 Moving device (moving section) W1, W2 Work (first work, second work)

Claims

1. A work stacking device for stacking a second work on a first work, comprising: a first acquisition unit that acquires the second work from one surface side of the work; a second acquisition unit that acquires the second work in the state acquired by the first acquisition unit from the other surface side of the work and releases one surface of the work; a moving unit that moves the second acquisition unit to position the second work in the state acquired by the second acquisition unit such that one surface of the work faces the first work; and when the second work is positioned on the first work, the second acquisition unit releases the second work and stacks the second work on the first work. A work stacking device.

2. In a state where the first acquisition unit has acquired the second work located below, the first acquisition unit rotates the second work in a lateral direction intersecting the vertical direction. The second acquisition unit faces the second work rotated in the lateral direction, and when the second acquisition unit acquires the second work, the second acquisition unit rotates the second work downward. The work stacking device according to Claim 1.

3. In a state where the second work faces the second acquisition unit, the first acquisition unit advances the second work toward the second acquisition unit side. The work stacking device according to Claim 2.

4. The first acquisition unit acquires the work by contacting and adsorbing one surface of the second work. The second acquisition unit acquires the work by contacting and adsorbing the other surface of the second work. The work stacking device according to Claim 1.

5. The work stacking device further comprises a third acquisition unit arranged to be rotated by a predetermined angle with respect to the first acquisition unit or the second acquisition unit. The third acquisition unit acquires the first work, and when the first work is moved by the moving unit to be positioned on a predetermined placement surface, the third acquisition unit releases the first work to place it on the placement surface. The work stacking device according to Claim 1.

6. a base that integrally supports the first to third acquisition units so as to be movable by the moving unit; and a control unit that controls the first to third acquisition units and the moving unit. The work stacking device further comprises: The third acquisition unit is arranged to be rotated by a predetermined angle with respect to the second acquisition unit. After the control unit causes the first acquisition unit to acquire the second workpiece, the control unit causes the moving unit to move the base so that the third acquisition unit can acquire the first workpiece, causes the third acquisition unit to acquire the first workpiece, and causes the moving unit to move the base so that the workpiece is positioned on the placement surface, and while the first workpiece is being placed on the placement surface, the control unit causes the second acquisition unit to acquire the second workpiece from the first acquisition unit. The workpiece stacking device according to claim 5.

7. A workpiece stacking method for a workpiece stacking device that stacks a second workpiece on a first workpiece, wherein the workpiece stacking device acquires the second workpiece from one surface side of the workpiece, re-acquires the second workpiece from the other surface side of the workpiece in the acquired state to release one surface of the workpiece, positions the second workpiece in the re-acquired state so that one surface of the workpiece faces the first workpiece, releases the second workpiece and stacks the second workpiece on the first workpiece workpiece stacking method.

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