JP2013111666A - Workpiece holding device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a workpiece holding device configured to hold a workpiece even when the shape of the workpiece is changed when the workpiece is bent.SOLUTION: The workpiece holding device 39 includes a plurality of workpiece holding parts 43 for holding the workpiece at a plurality of different portions of the workpiece W, and a workpiece holding part position changing part 45 for changing the positions of the workpiece holding parts according to the shape of the workpiece which is changed when the workpiece is machined.

Description

  The present invention relates to a work holding device, and more particularly to a work holding apparatus including a plurality of work holding units.

  Conventionally, a workpiece holding device that holds a workpiece using a vacuum pad (vacuum suction pad) is installed in a robot hand, and a plate-like workpiece is held and moved by the workpiece holding device, and the workpiece W is bent by a press brake. Things are known.

  Further, when processing the workpiece, the specifications of the workpiece holding device installed in the robot hand are changed according to the size and shape of the workpiece.

  That is, as shown in FIG. 19, work holding devices 301, 303, 305, and 307 having different specifications are prepared, and these are replaced with a robot hand to hold the work accurately.

  19A shows an H-type large-sized work holding device 301 having eight vacuum suction pads 309, and FIG. 19B shows an H-type having eight vacuum suction pads 309. A small work holding device 303 is shown, and FIG. 19C shows a T-type large work holding device 305 having eight vacuum suction pads 309, and FIG. A T-type and small work holding device 307 having eight suction pads 309 is shown.

  Moreover, Patent Literature 1 and Patent Literature 2 can be listed as literatures related to the conventional technology, for example.

Japanese Utility Model Publication No. 6-66982 JP-A-7-204746

  By the way, the conventional workpiece holding device has a problem that the workpiece may not be held when the shape of the workpiece is changed by bending the workpiece.

  That is, the conventional workpiece holding device is slightly smaller than the workpiece (product or semi-finished product) W, but as shown in FIG. 18A, the workpiece holding device 301 (303, 305,. When 307) becomes extremely small, the work W is bent by the dead weight of the work W, and handling by the robot becomes difficult.

  In addition, as shown in the upper diagram of FIG. 18B, there is a case where the workpiece W is subjected to deep bending (when it is performed).

  In this case, the workpiece W becomes smaller than the workpiece holding device 301 (303, 305, 307), and the workpiece W cannot be processed until the final process, and the workpiece W becomes an in-process product. For example, when deep bending is performed on the workpiece W, as shown in the lower diagram of FIG. 18B, the workpiece holding device 301 (303, 305) is started from the held surface of the workpiece W from an intermediate process. , 307) increases, and the die D or punch P interferes with the workpiece holding device 301 (303, 305, 307) when the workpiece W is bent. In order to avoid this interference, it is necessary to make the workpiece W once a work in progress.

  Further, when deep bending is performed on the workpiece W, even if the workpiece W can be held by the workpiece holding device 301 (303, 305, 307) until the final process, the bending is performed until the final process. When holding the workpiece W, the held surface (held portion) of the workpiece W must be set at a certain location. That is, when the workpiece W is held, the orientation of the workpiece W is restricted, and the posture of the workpiece W must be made constant.

  Accordingly, as shown in FIG. 18C, a large space is required when the workpiece W bent to the final process is placed on the pallet.

  In addition, as shown in FIG. 19, when a plurality of types of workpiece holding devices having different specifications are prepared, the cost increases, a storage place for the workpiece holding device is required, and further, setup by replacing the workpiece holding device. Time will occur.

  The present invention has been made in view of the above problems, and provides a workpiece holding device capable of holding a workpiece even when the shape of the workpiece is changed by bending the workpiece. For the purpose.

  The invention according to claim 1 has a plurality of workpiece holding portions that hold the workpiece at a plurality of different parts of the workpiece, and the shape of the workpiece changes when the workpiece is processed. A workpiece holding device having a workpiece holding unit position changing unit that changes the position of each workpiece holding unit according to a change.

  According to a second aspect of the present invention, in the work holding device according to the first aspect, the work holding unit position changing unit causes the link device in which each element constitutes a limited chain and the limited movement of the link device. And an actuator for holding a predetermined form of the link device. Each work holding unit is a work holding device supported by a link of the link device.

According to a third aspect of the present invention, in the work holding device according to the second aspect, the actuator includes a housing and a driving body that drives the housing, and constitutes the link device. Some elements of each of the elements are paired with the casing, and some other elements of the elements constituting the link device are with respect to the driving body. I have an even number,
It is a workpiece holding device configured such that a housing of the actuator is integrally installed on a robot arm.

  According to a fourth aspect of the present invention, in the workpiece holding device according to any one of the first to third aspects, at least two workpiece holding portions of the plurality of workpiece holding portions include the workpiece. The gripping work holding unit is configured to hold and hold, and the first gripping work holding unit which is one of the gripping work holding units and the other of the gripping work holding units A workpiece holding unit other than the holding workpiece holding unit is positioned between the second holding workpiece holding unit, which is one holding workpiece holding unit, and the workpiece holding unit position changing unit includes the first holding workpiece holding unit. It is a workpiece holding device that changes a distance between a workpiece holding unit and the second gripping workpiece holding unit.

  According to a fifth aspect of the present invention, there is provided a base body that is formed in a flat plate shape and a base body that is formed in a flat plate shape and on one side in one direction orthogonal to the thickness direction of the base body. A first moving body that is movable and positionable in a direction that approaches and moves away from the base body, and is formed in a flat plate shape and on the other side in one direction orthogonal to the thickness direction of the base body, with respect to the base body And a second moving body that can be moved and positioned in a direction to approach and move away from each other, an actuator that moves each of the moving bodies relative to the base body, a vacuum suction pad, and a magnet. One or more provided on the body, one or more provided on the first moving body, one or more provided on the second moving body, and a fixed claw and the fixed claw Vs. A movable claw that is movable in the direction of approaching and moving away, and an end portion of the first moving body that is located on the opposite side of the base body, and the second moving body, It is a workpiece holding device having a gripping workpiece holding portion provided at an end located on the opposite side of the base body.

  According to a sixth aspect of the present invention, there is provided an actuator including a housing, a male screw shaft that protrudes from the housing and rotates with respect to the housing about a predetermined axis, and is screwed to the male screw shaft. And a first elongated element that is engaged with the nut in a pair and is shorter than the first elongated element, and has one longitudinal end. The first long element is an intermediate portion in the longitudinal direction of the first elongate element with the other end portion in the longitudinal direction forming an even pair and engaging the casing of the actuator. The first casing engaging element engaged with the first longitudinal element and the longitudinal intermediate portion form a pair of the first longitudinal element at the longitudinal intermediate portion of the first elongated element. A second elongated element engaged; A third elongate element having the same length as that of the first elongate element and having one end in the longitudinal direction engaged with the nut in a pair of turns, and the first casing member The third long element is formed to have the same length as the combined element, one end in the longitudinal direction forms a pair and engages the casing of the actuator, and the other end in the longitudinal direction forms a pair. A second casing engaging element that is engaged with the third long element at the intermediate portion in the longitudinal direction, and the same length as the second long element, and the intermediate portion in the longitudinal direction is The third elongate element is engaged with the third elongate element at an intermediate portion in the longitudinal direction of the third elongate element, and one end portion in the longitudinal direction forms an encircling kinematic pair to form the first elongate element. One end of the element in the longitudinal direction is engaged with the first long element. And a fourth elongate elements being, to the each elongate element is a workpiece holding device having a plurality of workpiece holding portions provided integrally.

  According to the present invention, there is an effect that it is possible to provide a workpiece holding device that can hold a workpiece even when the shape of the workpiece is changed by bending the workpiece.

It is a front view which shows schematic structure of the press brake which carries out the bending process of the workpiece | work hold | maintained by the workpiece holding apparatus. It is a side view which shows schematic structure of a press brake, and is the II arrow directional view in FIG. It is a top view which shows schematic structure of a workpiece holding apparatus. It is a figure which shows the side view of a workpiece holding apparatus and the workpiece | work currently hold | maintained with a workpiece holding apparatus, and the workpiece holding apparatus shown to (a) is what looked at the workpiece holding apparatus of Fig.3 (a) from the arrow IVA. , (B) is a workpiece holding device as viewed in the direction of arrow IVB of the workpiece holding device of FIG. 3 (b). It is a figure which shows the side view of a workpiece | work holding device, and the workpiece | work currently hold | maintained with the workpiece holding device. It is a figure which shows the side view of a workpiece | work holding device, and the workpiece | work currently hold | maintained with the workpiece holding device. It is a figure which shows the workpiece | work currently hold | maintained with the workpiece holding apparatus, (a) has shown the workpiece | work which is not bent, (b) has shown the workpiece | work which has bent. (A) is the figure which showed an example of the workpiece | work before a bending process, (b) is the figure which showed an example of the workpiece | work after a bending process. It is a figure which shows an example of the workpiece | work in which the through-hole is formed. It is a perspective view which shows schematic structure of the workpiece holding apparatus of another form. It is a top view which shows schematic structure of the workpiece holding apparatus of another form. It is an enlarged view of the XII part in FIG. It is a XIII arrow directional view in FIG. It is a figure which shows the XIV-XIV cross section in FIG. (A) is the figure which looked at the workpiece holding apparatus shown in FIG. 11 from the opposite side to FIG. 11, (b) was the workpiece holding apparatus shown in FIG. 11 seen from the opposite side to FIG. It is a figure, Comprising: It is a figure which shows the state which changed the position of each workpiece | work holding | maintenance part. It is the figure which looked at the workpiece holding apparatus shown in FIG. 11 from the opposite side to FIG. 11, Comprising: It is a figure which shows the state which changed the position of each workpiece holding part. It is a figure which shows the modification of the installation aspect to the robot hand of a workpiece holding apparatus. It is a figure which shows the conventional workpiece holding apparatus and a workpiece | work. It is a figure which shows the conventional workpiece holding apparatus.

[First Embodiment]
The work holding device 39 according to the first embodiment of the present invention is installed, for example, at the tip of a robot arm (robot hand) 41 to hold a work (a plate-like work) W. The workpiece W held by the workpiece holding device 39 is handled (conveyed, positioned, changed in posture, etc.) by the robot arm 41.

  That is, the workpiece W held by the workpiece holding device 39 is handled by appropriately moving and positioning the robot arm 41 (including rotational positioning), and is automatically bent by the press brake 1. Yes.

  Here, the press brake 1 will be described in detail.

  The press brake (work bending machine) 1 uses a first mold (for example, a mold such as a die D) and a second mold (for example, a mold such as a punch P) to form a plate-shaped work W. (A flat plate workpiece or a flat plate portion of the workpiece) is bent.

  Hereinafter, for convenience of explanation, one horizontal direction is defined as an X-axis direction, another horizontal direction perpendicular to the X-axis direction is defined as a Y-axis direction, and orthogonal to the X-axis direction and the Y-axis direction. The direction (vertical direction) to be used is the Z-axis direction. The X-axis direction is the left-right direction of the press brake 1, and the Y-axis direction is the front-rear direction of the press brake 1.

  As shown in FIGS. 1 and 2, the press brake 1 includes a first mold installation body (for example, a lower table) 5 supported by the frame 3, a second mold installation body (for example, an upper table) 7, The crowning device 9 and the control device 15 are provided.

  A flat rear support plate 17 is integrally provided on the lower front side of the frame 3. A front support plate 19 having substantially the same shape as the rear support plate 17 is provided on the front side of the rear support plate 17. The thickness direction of the rear support plate 17 and the front support plate 19 is the Y-axis direction. When viewed from the Y-axis direction, the rear support plate 17 and the front support plate 19 are substantially overlapped with each other, and are developed in the YZ center plane (including the center of the press brake 1 in the Y-axis direction and the Z-axis direction). The planar upper end surface of the rear support plate 17 and the planar upper end surface of the front support plate 19 extend in a straight line in the X-axis direction.

  The front support plate 19 is supported by the rear support plate 17 via a spacer 21. As a result, a predetermined gap (gap whose dimension in the Y-axis direction is equal to the thickness of the spacer 21) 23 is formed between the rear support plate 17 and the front support plate 19.

  Further, a through hole 25 for installing the crowning device 9 is formed in the rear support plate 17 and the front support plate 19. The through-hole 25 is formed in, for example, a rectangular shape, and is formed as a single or a plurality (three in FIG. 1). The through hole 25 includes a lower surface 27 that extends in the horizontal direction and an upper surface 29 that is parallel to the lower surface 27. When viewed from the Y-axis direction, the through hole 25 and the front support plate 19 of the rear support plate 17. The through holes 25 overlap each other.

  Further, when a plurality of through holes 25 are provided, the positions of the through holes 25 coincide with each other in the Z-axis direction, with a predetermined interval in the X-axis direction, and on the YZ center plane of the press brake 1. They are arranged symmetrically.

  The lower table 5 is formed in a rectangular flat plate shape, for example. The thickness dimension of the lower table 5 is slightly smaller than the dimension of the gap 23. The lower table 5 is sandwiched between the rear support plate 17 and the front support plate 19 so that the thickness direction is in the Y-axis direction, and is positioned between the rear support plate 17 and the front support plate 19. ing. However, since the thickness dimension of the lower table 5 is slightly smaller than the dimension of the gap (interval) 23, the lower table 5 is in the state of being sandwiched between the rear support plate 17 and the front support plate 19. The table 5 is movable in the Y-axis direction and the Z-axis direction with respect to the rear support plate 17 and the front support plate 19.

  When viewed from the Y-axis direction, the dimension of the lower table 5 in the X-axis direction is slightly smaller than the dimensions of the rear support plate 17 and the front support plate 19 in the X-axis direction. The both ends of the lower table 5 in the X-axis direction are positioned outside the through hole 25. When viewed from the Y-axis direction, the planar upper end surface and the planar lower end surface of the lower table 5 extend linearly in the X-axis direction. Further, when viewed from the Y-axis direction, the planar upper end surface of the lower table 5 is located above the upper end surfaces of the rear support plate 17 and the front support plate 19, and The end face is located in the middle of the through hole 25 in the Z-axis direction. Thereby, when viewed from the Y-axis direction, a part of the lower table 5 is exposed at the through hole 25.

  Further, the lower table 5 has both ends in the X-axis direction via the pair of columnar shaft members (shaft members arranged symmetrically with respect to the YZ center plane) 31 and the front support plate 17 and the front side. The support plate 19 is supported. Thereby, the lower table 5 is a both-end support beam having both ends supported by the rotation support shaft. Note that the pair of shaft members 31 are located outside the through hole 25 in the X-axis direction.

  The upper table 7 is supported on the frame 3 by a linear guide bearing (not shown) on the upper front side of the frame 3. The upper table 7 is moved and positioned in the Z-axis direction (direction approaching or moving away from the lower table 5) by an actuator (such as a hydraulic cylinder) such as a servo motor 33 via a ball screw (not shown). It has become so.

  The upper table 7 is also formed in a flat plate shape, and is disposed above the lower table 5 away from the lower table 5 so that the thickness direction is the Y-axis direction. When viewed from the Y-axis direction, the upper table 7 is arranged symmetrically with respect to the YZ center plane, and the lower surface of the flat plate-like upper table 7 faces the lower surface of the lower table 5 in parallel and faces the X-axis direction. It extends in a straight line.

  The lower surface of the upper table 7 has the same length as the upper surface of the lower table 5 and is located at the same position as the lower table 5 in the X-axis direction. Furthermore, also in the Y-axis direction, the lower surface of the upper table 7 is located at the same position as the X-axis direction and the upper surface of the lower table 5.

  The servo motors 33 are provided on the left and right sides of the upper table 7 (arranged symmetrically with respect to the YZ center plane). The left servo motor 33A and the right servo motor 33B are driven substantially synchronously. When the pair of servo motors 33 (33A, 33B) is driven, the upper table 7 moves relative to the lower table 5 while the lower surface of the upper table 7 is kept substantially parallel to the upper surface of the lower table 5. It has become. Further, by stopping the driving of the servo motor 33 and preventing the rotation output shaft of the servo motor 33 from rotating (for example, by applying a servo brake to the rotation output shaft), the upper table 7 is positioned and this position is changed. To be maintained.

  Note that the lower table 5 may be moved and positioned in the Z-axis direction instead of or in addition to the upper table 7 being moved and positioned. In any case, any configuration is acceptable as long as the upper table 7 can be relatively moved and positioned in the direction in which the upper table 7 approaches and separates from the lower table 5.

  For example, a first die (for example, a die D) is detachably and integrally installed on the lower table 5 via a die holder DH. A second die (for example, punch P) is detachably and integrally installed on the upper table 7 via, for example, a punch holder PH.

  In the Y-axis direction, the center of the punch (installed punch) P installed on the upper table 7 and the center of the die (installed die) D installed on the lower table 5 coincide with each other. . In FIG. 1, the dimensions in the X-axis direction of the punch P, the punch holder PH, the die D, and the die holder DH are the same as the dimensions in the X-axis direction of the lower table 5 and the upper table 7. , The dimension in the X-axis direction of the punch P, punch holder PH, die D, and die holder DH is smaller than the dimension in the X-axis direction of the lower table 5 and the upper table 7, and the punch P, punch holder PH, die D and the die holder DH are arranged in the X-axis direction at a position biased to the center of the lower table 5 or the upper table 7 or to the left or right.

  The press brake 1 is provided with a back gauge 37. The back gauge 37 is provided on the rear side of the punch P or die D (lower table 5 or upper table 7), and is supported by the frame 3 via a linear guide bearing (not shown). The actuator can be moved and positioned with respect to the frame 3 in the Y-axis direction by an actuator.

  Then, as shown in FIG. 2, the workpiece W is placed on the die D while the upper table 7 is raised and the installed punch P is separated from the installed die D above the installed die D. When the upper table 7 is lowered with one end abutting against the back gauge 37, the workpiece W is sandwiched between the “V” -shaped concave portion of the die D and the “V” -shaped convex portion of the punch P. W is bent.

  The crowning device 9 is a device that performs crowning on the lower table 5, and includes, for example, a hydraulic cylinder 35. The hydraulic cylinder 35 is installed in each of the through holes 25 of the support plates 17 and 19. The lower end of the casing of the hydraulic cylinder 35 is in contact with the lower surface of the through hole 25 and is provided integrally with the support plates 17 and 19. The tip (upper end) of the rod of the hydraulic cylinder 35 is in contact with the lower surface of the upper table 7.

  The lower table 5 is crowned by supplying compressed oil (hydraulic hydraulic oil whose pressure is higher than atmospheric pressure) to the hydraulic cylinder 35. By the crowning of the lower table 5, the lower table 5 (punch P) becomes a slightly convex curve upward as shown by a broken line L1 in FIG.

  Here, the workpiece holding device 39 will be described in detail with reference to FIGS.

  The workpiece holding device 39 includes a workpiece holding unit 43 and a workpiece holding unit position changing unit 45.

  A plurality of work holding portions 43 each formed of a vacuum suction pad or the like are provided and are separated from each other. Accordingly, each of the workpiece holding units 43 holds the workpiece (one workpiece) W at a plurality of parts different from each other.

  The workpiece holding unit position changing unit 45 is a device that changes the position of each workpiece holding unit 43 such that the distance between the workpiece holding units 43 changes. The change of the position of the work holding part 43 by the work holding part position changing part 45 is performed by, for example, processing the work W (for example, a flat work or a flat part of the work is bent by the press brake 1). This is a device that changes the position of the work holding portion 43 in accordance with the change of the shape when the shape of the work W changes (because of the processing).

  The plurality of workpiece holding portions 43 are arranged on, for example, substantially one plane. The distance between all the workpiece holding units 43 or the distance between some workpiece holding units 43 is changed by the workpiece holding unit position changing unit 45. The distance between the workpiece holding units 43 changed by the workpiece holding unit position changing unit 45 is maintained until the distance between the workpiece holding units 43 is next changed by the workpiece holding unit position changing unit 45. It has become so.

  At least two of the plurality of workpiece holding units 43, which are part of the workpiece holding units 43, are gripping workpiece holding units (work holding units) 47 that hold (hold) the workpiece W. It is configured. The other work holding unit 43 includes a suction work holding part (vacuum pad; may be a magnet such as an electromagnetic magnet) 49 that sucks and holds the vacuum suction work.

  In addition, the first gripping work holding unit 47 </ b> A that is one gripping work holding unit among the gripping work holding units 47 and the second gripping that is another gripping work holding unit among the gripping work holding units 47. Between the workpiece holding unit 47B, a workpiece holding unit other than the gripping workpiece holding unit 47 (the suction workpiece holding unit 49 or the suction workpiece holding unit 49 and the gripping workpiece holding unit 47) is located.

  The work holding part position changing unit 45 changes at least the distance between the first gripping work holding part 47A and the second gripping work holding part 47B.

  The workpiece holding unit 43 will be described in more detail.

  Hereinafter, for convenience of explanation, a predetermined one direction in the work holding device 39 is set as a U-axis direction, another predetermined direction orthogonal to the U-axis direction is set as a V-axis direction, and the U-axis direction and the V-axis direction. The direction orthogonal to the direction is taken as the W-axis direction. Since the workpiece holding device 39 is installed on the robot arm (robot hand) 41, the U-axis direction, the V-axis direction, and the W-axis direction in the workpiece holding device 39 coincide with the X-axis direction, the Y-axis direction, and the Z-axis direction. In some cases.

  The work holding device 39 includes a base body 51, a first moving body 53, a second moving body 55, an actuator 57, a suction work holding section 49, and a gripping work holding section 47.

  The base body 51 is formed in a rectangular flat plate shape. The first moving body 53 is formed in a rectangular flat plate shape, and is on one side (in the U-axis direction) orthogonal to the thickness direction (W-axis direction) of the base body 51 (in FIG. 3). On the left side, it can be moved and positioned in a direction (U-axis direction) approaching or moving away from the base body 51.

  The second moving body 55 is formed in a rectangular flat plate shape having the same shape as the first moving body 53, and is in one direction (U-axis direction) orthogonal to the thickness direction (W-axis direction) of the base body. ) On the other side (the right side in FIG. 3) is movable and positionable in a direction approaching / separating from the base body 51.

  The actuator 57 moves and positions the movable bodies 53 and 55 with respect to the base body 51.

  The base body 51 and the movable bodies 53 and 55 are located at substantially the same place in the W-axis direction. More specifically, the moving bodies 53 and 55 are located at the same position in the W-axis direction, and the base body 51 is different from the moving bodies 53 and 55 in the W-axis direction. The positions of the bodies 53 and 55 are shifted by the thickness.

  When viewed from the W-axis direction, the lateral direction of the rectangular base body 51 and the movable bodies 53 and 55 is the U-axis direction, and the vertical direction of the rectangular base body 51 and the movable bodies 53 and 55 is V. It is in the axial direction. The base body 51 and the moving bodies 53 and 55 have substantially the same vertical dimension. The lateral dimension of the base body 51 is larger than the lateral dimension of each moving body 53, 55.

  Further, when viewed from the W-axis direction, the base body 51 and the moving bodies 53 and 55 are located at substantially the same position in the V-axis direction. The first moving body 53 is located on one side (left side in FIG. 3) of the base body 51 in the U-axis direction, and the second moving body 55 is positioned on the base body 51 in the U-axis direction. Is located on the other side (right side in FIG. 3).

  Since the first moving body 53 is supported by the base body 51 via the linear guide bearing 59, the first moving body 53 can move in the U-axis direction described above with respect to the base body 51. . When the first moving body 53 comes closest to the base body 51, the first moving body 53 comes into contact with the base body 51 as shown in FIG. Since the second moving body 55 is also supported by the base body 51 via the linear guide bearing 59, the second moving body 55 can move in the U-axis direction described above with respect to the base body 51. . When the second moving body 55 comes closest to the base body 51, the second moving body 55 is also in contact with the base body 51.

  The moving stroke of the first moving body 53 and the moving stroke of the second moving body 55 are equal to each other.

  The actuator 57 includes a first actuator (for example, a pneumatic cylinder) 57A that moves the first moving body 53, and a second actuator (for example, a pneumatic cylinder) 57B that moves the second moving body 55. It is configured. Accordingly, the position of the first moving body 53 relative to the base body 51 and the position of the second moving body 55 relative to the base body 51 can be moved and positioned independently of each other.

  Note that the first moving body 53 and the second moving body 55 may be moved in synchronization with each other using one actuator and a synchronization mechanism (rack & pinion or the like).

  Further, instead of employing a pneumatic cylinder as the actuator 57, a linear motor or the like may be employed. This makes it easy to stop and position the moving bodies 53 and 55 at an arbitrary intermediate position.

  As described above, the suction work holding unit 49 is configured by at least one of a vacuum suction pad (vacuum pad) and a magnet (a magnet capable of turning on and off a magnetic force such as an electromagnet) (in FIG. Pad is used). A plurality of suction work holding portions 49 are provided on the base body 51 (only one may be provided). Further, a plurality of suction work holding portions 49 are provided in the first moving body 53 (a configuration in which only one suction work holding portion 49 is provided) may be used. In addition, a plurality of suction work holding portions 49 are provided on the second moving body 55 (only one may be provided).

  Each suction work holding portion 49 is provided so as to protrude from one surface in the thickness direction (W-axis direction) of the base body 51 and the movable bodies 53 and 55. In addition, the suction line (suction surface) of each suction work holding portion 49 is 1 away from the base body 51 and each movable body 53, 55 by a predetermined distance in the thickness direction of the base body 51 or each movable body 53, 55. It exists on two planes (planes developed in the U-axis direction and the V-axis direction).

  More specifically, the base body 51 is provided with six suction work holding portions 49. Of the six suction workpiece holders 49, four suction workpiece holders 49 are provided in the vicinity of the four corners of the base body 51. The other two suction work holding portions 49 are provided in the vicinity of both ends of the base body 51 in the V-axis direction and in the center of the base body 51 in the U-axis direction.

  The first moving body 53 is provided with four suction work holding portions 49. Of the four suction work holding parts 49, two suction work holding parts 49 are provided in the vicinity of the corners of the first moving body 53 on the base body 51 side. The other two suction work holding portions 49 are provided in the vicinity of both ends of the first moving body 53 in the V-axis direction and in the intermediate portion of the first moving body 53 in the U-axis direction.

  Similarly to the first moving body 53, the second moving body 55 is provided with four suction work holding portions 49 as in the case of the first moving body 53. Of the four suction workpiece holding portions 49, two suction workpiece holding portions 49 are provided in the vicinity of the corner portion of the second moving body 55 on the base body 51 side. The other two suction work holding portions 49 are provided in the vicinity of both ends of the second moving body 55 in the V-axis direction and in the intermediate portion of the second moving body 55 in the U-axis direction.

  The vacuum suction is simultaneously turned on / off for each of the 14 suction workpiece holders 49 in total, but each of the suction workpiece holders 49 is independently turned on / off. Alternatively, it may be turned on / off for each predetermined group. For example, six suction work holding parts 49 provided on the base body 51 are turned on / off at the same time, and four suction work holding parts 49 provided on the first moving body 53 are simultaneously provided. The four suction work holding portions 49 provided on the second moving body 55 may be turned on / off at the same time.

  The gripping work holding unit 47 is provided at an end portion (near the end) of the first moving body 53 located on the opposite side of the base body 51 in the U-axis direction. Further, two gripping work holding parts 47 are provided on the first moving body 53, and one gripping work holding part 47 is provided near both ends of the first moving body 53 in the V-axis direction. It has been.

  Further, the gripping work holding portion 47 is provided at an end portion (near the end) of the second moving body 55 located on the side opposite to the base body 51 in the U-axis direction. Further, two gripping work holding parts 47 are provided on the second moving body 55, and one gripping work holding part 47 is provided near both ends of the second moving body 55 in the V-axis direction. It has been.

  Thereby, the gripping work holding part 47 is located at both ends of the work holding device 39, and the suction work holding part 49 exists inside the gripping work holding part 47 in the U-axis direction.

  A total of four gripped work holding portions 47 are arranged in the vicinity of the four corners of the work holding device 39 when viewed from the W-axis direction. In addition, the four gripping work holding portions 47 are located at the same position in the W-axis direction and protrude in the same direction as the suction work holding portion 49. The protrusion height is lower than 49.

  The gripping work holding part 47 includes a fixed claw 61, a movable claw 65 that can move in a direction approaching and moving away from the fixed claw 61, and a base part (grip work holding part main body part) 63. .

  The gripping work holding part main body 63 is provided integrally with the first moving body 53 (second moving body 55). The fixed claw 61 is provided integrally with the gripping work holding part main body 63. The movable claw 65 is supported by the gripping work holding part main body 63 via a linear guide bearing (not shown), and is held in the U-axis direction by an actuator (not shown) such as a pneumatic cylinder. It moves with respect to the part 63.

  Then, by moving the movable claw 65, the work W is gripped and held by the fixed claw 61 and the movable claw 65, or the work W is released.

  Further, the movable claw 65 is formed in an “L” shape. When the movable claw 65 is moved to the fixed claw 61 side so as to grip the work W, the movable claw 65 is moved to the fixed claw 61 when the work W does not exist. The fixed claw 61, the gripping work holding part main body 63, and the movable claw 65 are in contact with each other and configured to have a “B” shape. When the workpiece W is gripped by the fixed claw 61 and the movable claw 65, the edge of the workpiece W (the edge formed by bending or the like) can enter the inside of the “B” shape. (See FIG. 6 (a)).

  As already understood, the workpiece holding device 39 is symmetric with respect to the center plane (a plane passing through the center of the workpiece holding device 39 and orthogonal to the U-axis direction).

  Further, the base body 51 is integrally installed at the tip of the robot hand via the bracket 67.

  Next, the operation of the work holding device 39 and the like will be described.

  First, as an initial state, the upper table 7 is raised, work information related to the shape of the work W or the like is input to the control device 15 via an input unit (not shown), and a plurality of plate-like works W are formed. The workpiece holding device 39 is integrally installed on the robot arm 41 of the robot 69 (see FIG. 4 and the like), and the moving bodies 53 and 55 of the workpiece holding device 39 are respectively connected. As shown in FIG. 3B, it is assumed that the entire workpiece holding device 39 protrudes from the base body 51 and is located at a predetermined default position.

  In the initial state, when a start button (not shown) is pressed, the robot 69, the work holding device 39, and the press brake 1 perform the following operations under the control of the control device 15.

  First, the back gauge 37 of the press brake 1 is moved and positioned, and the workpiece holding device 39 is appropriately moved by the robot 69, and one workpiece W among the stacked workpieces W is held by the suction workpiece holding portion 49.

  Subsequently, the workpiece W is placed on the die D and positioned by abutting against the back gauge 37 (see FIG. 4A).

  Subsequently, the punch P is lowered while the workpiece W is held by the workpiece holding device 39, and the workpiece W is bent. When bending the workpiece W, both ends of the workpiece W jump up, and the workpiece holding device 39 is rotated and moved by the robot 69 in accordance with the jump (see FIG. 4B). In addition, when bending the workpiece | work W, crowning by the crowning apparatus 9 is made as needed.

  Subsequently, the punch P is raised, the bent work W is unloaded from the press brake 1, and the unloaded work W is once separated from the work holding device 39 and placed at a predetermined position.

  Subsequently, as shown in FIG. 3A, the movable bodies 53 and 55 of the workpiece holding device 39 are retracted to the base body 51 side, and the workpiece W is held again by the suction workpiece holding portion 49 (the workpiece W is held by the workpiece W). (Change it). Further, the back gauge 37 is positioned again.

  Subsequently, the workpiece W is placed again on the die D, and positioned against the back gauge 37 (see FIG. 5A).

  Subsequently, the punch P is lowered again while holding the workpiece W by the workpiece holding device 39, and the workpiece W is bent. When the workpiece W is bent, both ends of the workpiece W jump up, and the workpiece holding device 39 is rotated and moved by the robot 69 in accordance with the jump (see FIG. 5B).

  Subsequently, the punch P is raised, the bent work W is unloaded from the press brake 1, and the unloaded work W is once separated from the work holding device 39 and placed at a predetermined position.

  Subsequently, the workpiece W is held by the gripping workpiece holding portion 47 of the workpiece holding device 39 (see FIG. 6A), and the workpiece W is conveyed to a predetermined position (a place where the bent workpiece is stored). And the work holding device 39 returns to the default position.

  Subsequently, the second workpiece W is bent in the same manner as the first workpiece W. However, when the bending of the second workpiece W is finished, as shown in FIG. 6B, the workpiece W is held by the suction workpiece holding portion 49 and stored at a predetermined position (the storage of the bent workpiece W). Location) Transport to location and release workpiece W. In FIG. 6B, the postures of the two “U” -shaped workpieces W are shifted from each other by 180 °, and a part of the other workpiece W (folded portion) in one workpiece W. Since the space enters, the installation space for the workpiece W is reduced.

  Subsequently, the above-described bending of the two workpieces W is executed alternately until the workpieces W disappear, and the initial state is restored.

  According to the work holding device 39, since the position of each work holding part 43 can be changed by the work holding part position changing part 45, when the shape of the work W is changed by bending the work W or the like. Even if it exists, the workpiece | work W can be hold | maintained correctly.

  That is, when the work holding device 39 is likely to be extremely small as compared with the work W, the distance between the work holding parts 43 is increased by the work holding part position changing part 45, so that almost the entire work W can be obtained. The workpiece W can be held, and the deflection of the workpiece W due to its own weight (the deflection when held by the workpiece holding device 39) can be prevented, and the workpiece W is shaken (when the workpiece W is held by the workpiece holding device 39). Can be prevented, and handling of the workpiece W by the robot 69 becomes easy.

  Even if the workpiece W is deep-bent and the workpiece W becomes smaller than the workpiece holding device 39 (see FIG. 8 etc.), the distance between the workpiece holding portions 43 is reduced by the workpiece holding portion position changing portion 45. By doing so, the workpiece W can be held, the workpiece W can be processed until the final process, and the workpiece W is prevented from becoming a work-in-process.

  Further, as shown in FIG. 19, since it is not necessary to prepare a plurality of types of workpiece holding devices having different specifications, it is possible to suppress an increase in cost, and a storage place for various types of workpiece holding devices 39 becomes unnecessary. Furthermore, the setup time due to the exchange of the workpiece holding device 39 is eliminated, and the cycle time for machining the workpiece W can be shortened.

  Further, after the workpiece W is held by the workpiece holding device 39 as shown in FIG. 7A, the distance between the workpiece holding portions 43 is changed by the workpiece holding portion position changing portion 45 as shown in FIG. If it changes so that it may become slightly small, as shown in FIG.7 (b), slight bending (bending-like bending) will generate | occur | produce in the workpiece | work W. FIG. As a result, it is possible to prevent two plate-like workpieces W from being hung. And it becomes easy to automate the bending process of the workpiece W using the robot 69, the workpiece holding device 39, and the press brake.

  In order to prevent two workpieces W from being hung, the state shown in FIG. 7B is assumed only when the uppermost one workpiece W that is stacked is lifted.

  Further, as shown in FIG. 9, when there is a possibility that the workpiece holding portion 43 interferes with the through-hole W <b> 1 formed in the workpiece W, the position of the workpiece holding portion 43 is appropriately changed by the workpiece holding portion position changing portion 45. Thus, interference between the work holding portion 43 and the through hole W1 formed in the work W can be avoided, and the work W can be held accurately.

  Further, according to the work holding device 39, since the work holding part 43 is configured by the suction work holding part 49 and the gripping work holding part 47, by separately using the suction work holding part 49 and the gripping work holding part 47, The workpiece W having a wider range and various shapes can be held in various modes.

  For example, as shown in FIGS. 6 and 8, when holding the workpiece W that has been bent deeply and further bent to the final process, it is not necessary to make the held portion of the workpiece W constant. (Comparison with FIG. 6A and FIG. 6B), when the work W is held on the pallet after being bent until the final process because the restriction on the orientation of the work W when holding the work W is reduced. Can be made smaller (see FIG. 6B).

[Second Embodiment]
The workpiece holding device 71 according to the second embodiment is installed at the tip of the robot arm 41 in the same manner as the workpiece holding device 39 according to the first embodiment, and holds and transfers the workpiece W.

  In other words, the workpiece W held by the workpiece holding device 71 is handled (conveyed, positioned, changed in posture, etc.) by the robot arm 41.

  The work holding device 71 will be described in detail.

  As shown in FIG. 10, FIG. 11 and the like, the work holding unit position changing unit 45 of the work holding device 71 includes a link device (link mechanism) 75 in which a plurality of elements (a plurality of members) 73 form a limited chain. The link device 75 is provided with an actuator 77 that performs a limited motion and holds a predetermined form of the link device 75.

  Each work holding part 43 is supported by the element 73 of the link device 75 (for example, provided integrally).

  The actuator 77 includes a housing 79 and a driving body 81 that drives (moves and outputs a driving force) with respect to the housing 79.

  Some of the elements 73E and 73F among the elements 73 constituting the link device 75 are paired with the casing 79, and the other elements 73 constituting the link device 75 are the other elements 73. Some elements (73A, 73C) are paired with the drive body 81, and the casing 79 of the actuator 77 is installed integrally with the robot arm 41 by a fastener such as a bolt via a bracket, for example. (See FIG. 14).

  The work holding device 71 will be described in more detail.

  Hereinafter, for convenience of explanation, a predetermined one direction in the work holding device 71 is defined as a U-axis direction, another predetermined direction orthogonal to the U-axis direction is defined as a V-axis direction, and the U-axis direction and the V-axis direction. The direction orthogonal to the direction is taken as the W-axis direction. Since the workpiece holding device 71 is installed on the robot arm 41, the U axis direction, the V axis direction, and the W axis direction in the workpiece holding device 71 may coincide with the X axis direction, the Y axis direction, and the Z axis direction.

  As described above, the actuator 77 is attached to the casing 79 around the casing (element) 79 and a rotation centering on a predetermined axis (center axis C1 extending in the V-axis direction) protruding from the casing 79 in the V-axis direction. A male screw shaft (element; drive body) 81 that is rotationally driven is provided. Speaking openly, the actuator 77 is constituted by a servo motor with a male screw shaft in which a male screw is integrally provided on a rotation output shaft, for example.

  A nut (element) 83 is screwed onto the male screw shaft 81. Since the nut 83 is supported by the element 73 of the link device 75, the nut 83 does not rotate around the axis C1, but the male screw shaft 81 rotates in the longitudinal direction (V-axis direction, C1 axis). Direction).

  The male screw shaft 81 and the nut 83 are configured by normal slide screws that are self-locking, such as triangular screws and trapezoidal screws, but the male screw shaft 81 and the nut 83 may be configured by ball screws. In the case where the male screw shaft 81 and the nut 83 are formed of ball screws, a brake such as a servo brake that prevents the male screw shaft 81 from rotating when the male screw shaft 81 stops rotating is necessary.

  The actuator 77 may be a cylinder such as a pneumatic cylinder or a hydraulic cylinder. In this case, the cylinder body (cylinder body) corresponds to the housing 79 of the servo motor 77, and the cylinder rod of the cylinder corresponds to the male screw shaft 81 of the servo motor 77. In place of the nut 83, a cylinder rod tip member is integrally provided at the tip of the cylinder rod.

  The first elongate element 73A is formed in a linear bar shape whose cross-sectional shape by a plane orthogonal to the longitudinal direction is an “H” shape or an “I” shape. The first elongate element 73A has a portion in the vicinity of one end portion in the longitudinal direction that pivots (swings) around the rotation center axis C11 around the nut 83 as a pair. ing. The axis C11 passes through the center of the nut 83 and is orthogonal to the axis C1 and extends in the W-axis direction. Note that the axis C11 is not orthogonal to the axis C1 (does not intersect) and may be slightly separated from the axis C1. That is, the axis C11 may exist at a twisted position with respect to the axis C1.

  The first elongate element 73A extends on the one side of the axis C1 in an oblique direction including a component in the U-axis direction and a component in the V-axis direction (not including a component in the W-axis direction) from the axis C11. doing. That is, the first elongate element 73A extends obliquely from the axis C1 away from the axis C1 (servo motor 77) in the U-axis direction and toward the housing 79 side of the servo motor 77 in the V-axis direction. doing. Since the first long element 73A is sufficiently longer than the size of the servo motor 77, the first long element 73A once approaches the casing 79 of the servo motor 77 in the V-axis direction. After that, it is stretched away.

  The first housing engaging element 73E is formed in a linear shape with a rod shape in which the cross-sectional shape by a plane orthogonal to the longitudinal direction is the same shape as the first long element 73A. The first housing engaging element 73E is formed shorter than the first long element 73A, and one end portion in the longitudinal direction is engaged with the housing 79 of the actuator 77 in pairs.

  The other end portion in the longitudinal direction of the first housing engaging element 73E forms a counter pair, and the first long element 73A is a portion on the engaging portion side between the first long element 73A and the nut 83. Is engaged with the first long element 73A at an intermediate portion in the longitudinal direction.

  In other words, the first casing engaging element 73E has a portion in the vicinity of one end in the longitudinal direction that rotates around the casing 79 of the servo motor 77 with the rotation center axis C12 as the center of rotation. It moves (oscillates). Further, the first casing engaging element 73E has a portion in the vicinity of the other end in the longitudinal direction around the rotation center axis C13 as a rotation center, and makes a pair even with respect to the first long element 73A. It is designed to rotate (swing).

  The rotation center axes C12 and C13 are parallel to the axis C11 and extend in the W-axis direction. The rotation center axis C12 is slightly separated from the casing 79 of the servo motor 77 on the side where the first long element 73A extends (positioned at a twist position; in FIG. 11, from the axis C1). However, the rotation center axis C12 may be at a position orthogonal to the axis C1. The axis C13 is located on one end side (near the axis C11) of the first long element 73A in the longitudinal direction of the first long element 73A.

  The second long element 73B is formed to have the same length as the first long element 73A, for example. More specifically, it is formed in substantially the same shape as the first long element. The second long element 73B has a first intermediate portion (for example, the central portion) in the longitudinal direction of the first long element 73A. Is engaged with the long element 73A.

  The second elongate element 73B has a center portion in the longitudinal direction around the rotation center axis C14 as a center of rotation and a pair of pairs around the center portion in the longitudinal direction of the first elongate element 73A. No rotation (oscillation). The axis C14 is parallel to the axis C11 and extends in the W-axis direction.

  The third long element 73C is formed in the same length as the first long element 73A. More specifically, it is formed in substantially the same shape as the first long element 73A. The third elongate element 73C has one end in the longitudinal direction at the same location as the engagement location between the nut 83 and the first elongate element 73A. It is engaged with the element 73A.

  The third long element 73C has a center plane (a plane including the axis C1 and orthogonal to the U-axis direction; a plane including the axis C1 and extending in the V-axis direction and the W-axis direction). The first elongate element 73A is symmetrical. The third long element 73C rotates with respect to the nut with the axis C11 as the rotation center.

  As described above, the elements 73A and 73C are in an indirect form via the nut 83, but form an even number with respect to the drive body 81.

  The second housing engaging element 73F is formed to have the same length as the first housing engaging element 73E. More specifically, it is formed in the same shape as the first housing engaging element 73E. The second casing engaging element 73F is engaged with the casing 79 of the actuator 77 with one end in the longitudinal direction turning around and making a pair. Further, the second casing engaging element 73F has a pair of other ends in the longitudinal direction that are paired with each other, and is engaged with the third elongated element 73C at an intermediate portion in the longitudinal direction of the third elongated element 73C. doing.

  The second housing engaging element 73F has a central plane (a plane including the axis C1 and perpendicular to the U-axis direction; a plane including the axis C1 and extending in the V-axis direction and the W-axis direction). On the other hand, it is symmetrical with the first housing engaging element 73E. Therefore, the second housing engaging element 73F rotates with respect to the housing 79 of the actuator 77 with the axis (axis symmetrical to the axis C12) C32 as the rotation center. Further, the second housing engaging element 73F rotates with respect to the third long element 73C with an axis (an axis symmetrical to the axis C13) C33 as a rotation center. .

  The fourth long element 73D is formed to have the same length as the second long element 73B. More specifically, for example, it is formed in substantially the same shape as the second long element 73B. In the fourth long element 73D, the intermediate portion (for example, the central portion) in the longitudinal direction forms a counter pair, and the third long element 73D is the intermediate portion (for example, the central portion) in the longitudinal direction of the third long element 73C. The scale element 73C is engaged. The fourth long element 73D has one end in the longitudinal direction (the end located on the opposite side of the nut 83 with the casing 79 of the actuator 77 in between) and makes a counter pair. One long element 73A is engaged with the first long element 73A at one end in the longitudinal direction (the end located on the opposite side of the nut 83 with the casing 79 of the actuator 77 in between). Yes.

  The fourth elongate element 73D has a central plane (a plane including the axis C1 and orthogonal to the U-axis direction; a plane including the axis C1 and extending in the V-axis direction and the W-axis direction). On the other hand, it is symmetrical with the second long element 73B. The fourth elongate element 73D rotates with respect to the third elongate element 73C with the axis C34 as the rotation center. The fourth elongate element 73D rotates with respect to the second elongate element 73B with the axis C22 as the rotation center. The axis C22 is orthogonal to the axis C1.

  Actuator 77, nut 83, first long element 73A, second long element 73B, third long element 73C, fourth long element 73D, first housing engaging element 73E, second Since the housing engaging element 73F is engaged as described above, the link device 75 in which the actuator 77, the nut 83, and each element 73 perform limited movement is configured.

  In the work holding device 71, the casing 79 of the actuator 77 is a fixed node, the male screw shaft 81 is a driving node, and each element 73 is a driven node or a connecting node. The long elements 72A, 73B, 73C, and 73D and the housing engaging elements 73E and 73F are located at substantially the same position in the W-axis direction.

  The work holding portion 43 is integrally provided on each of the long elements 72A, 73B, 73C, and 73D via, for example, a bracket 85 (see FIGS. 12, 13 and the like). A plurality of workpiece holding units 43 are provided, and all the workpiece holding units 43 are configured by suction workpiece holding units 49, but at least a part of the workpiece holding units 43 are configured by gripping workpiece holding units 47. May be.

  Each work holding part 43 is installed in each long element 72A, 73B, 73C, 73D away from each other. Further, the work holding part 43 protrudes to one side of each of the long elements 72A, 73B, 73C, 73D in the V-axis direction. Even if the position of the nut 83 changes and the long elements 72A, 73B, 73C, and 73D move, the workpiece suction surface of each workpiece holding portion 43 is orthogonal to the W axis. On the plane (a plane separated from each of the long elements 72A, 73B, 73C, 73D by a predetermined distance).

  For example, 16 workpiece holding portions 43 (vacuum suction pads) are provided. The first vacuum suction pad 43A is provided between the axis C11 (C13) and the axis C15. The second vacuum suction pad 43B is provided in the middle between the axis C15 and the axis C14. The sixth vacuum suction pad 43F is provided at the axis C16. The fifth vacuum suction pad 43E is provided at the other end in the longitudinal direction of the second long element 73B.

  The third vacuum suction pad 43C, the fourth vacuum suction pad 43D, the seventh vacuum suction pad 43G, and the eighth vacuum suction pad 43H are center planes (including the axis C14 and the axis C34 and orthogonal to the axis C1. And the sixth vacuum suction pad 43F, the fifth vacuum suction pad 43E, the second vacuum suction pad 43B, and the first vacuum suction pad 43A.

  Ninth vacuum suction pad 43I, tenth vacuum suction pad 43J, eleventh vacuum suction pad 43K, twelfth vacuum suction pad 43L, thirteenth vacuum suction pad 43M, fourteenth vacuum suction pad 43N, fifteenth The vacuum suction pad 43O and the sixteenth vacuum suction pad 43P of the first vacuum suction pad 43A and the second vacuum suction pad 43B with respect to the center plane (a plane including the axis C1 and orthogonal to the U axis). Symmetric with the third vacuum suction pad 43C, the fourth vacuum suction pad 43D, the fifth vacuum suction pad 43E, the sixth vacuum suction pad 43F, the seventh vacuum suction pad 43G, and the eighth vacuum suction pad 43H. Is provided.

  Further, the work holding device 71 includes a first medium element 73G, a second medium element 73H, a third medium element 73I, a fourth medium element 73J, a fifth medium element 73K, 6 medium-sized elements 73L, seventh medium-sized elements 73M, eighth medium-sized elements 73N, first short elements 73O, and second short elements 73P are provided.

  These medium-sized elements 73G to 73N and short elements 73O and 73P are provided to increase the rigidity of the link device 75, and the cross-sectional shape by a plane orthogonal to the longitudinal direction is the first long element. It has the same shape as 73A and is formed in a rod shape, and is located at substantially the same place as the long elements 73A to 73D and the housing engaging elements 73E and 73F in the W-axis direction.

  More specifically, the first medium-sized element 73G is shorter than the first long element 73A and longer than the first housing engaging element 73E. One end portion in the longitudinal direction of the first medium-sized element 73G is an intermediate portion between the shaft C11 (C13) and the shaft C14, and the first long-sized element 73A is rotatable about the shaft C15. Is engaged.

  The second medium-sized element 73H has the same length as the first medium-sized element 73G. One end portion in the longitudinal direction of the second medium-sized element 73H is an intermediate portion between the shaft C14 and the other end in the longitudinal direction of the second long element 73B, and the second long length with the shaft C16 as a rotation center. The shank element 73B is rotatably engaged. The other end of the second medium-sized element 73H in the longitudinal direction is engaged with the first medium-sized element 73G at the other end of the first medium-sized element 73G, and the axis C17 is the center of rotation. Thus, the first medium-sized element 73G is rotatable.

  Here, the distance between the axis C14 and the axis C15, the distance between the axis C15 and the axis C17, the distance between the axis C16 and the axis C17, and the distance between the axis C14 and the axis C16 Are equal to each other.

  The third medium-sized element 73I and the fourth medium-sized element 73J are the first medium-sized elements with respect to the center plane (a plane that includes the axes C14 and C34 and is orthogonal to the axis C1). 73G is symmetrical to the second medium-sized element 73H. Therefore, the axes C18, C19, and C20 are symmetrical with the axes C16, C15, and C17 with respect to the center plane (a plane that includes the axes C14 and C34 and is orthogonal to the axis C1). .

  The fifth medium-sized element 73K, the sixth medium-sized element 73L, the seventh medium-sized element 73M, and the eighth medium-sized element 73N are center planes (planes that include the axis C1 and are orthogonal to the U-axis). In contrast, the first medium-sized element 73G, the second medium-sized element 73H, the third medium-sized element 73I, and the fourth medium-sized element 73J are symmetrical. Therefore, the axis C34, the axis C35, the axis C36, the axis C37, the axis C38, the axis C39, and the axis C40 are set so that the axis C14, the axis C15, the axis C14, the center plane (the plane that includes the axis C1 and is orthogonal to the U axis). The axis C16, the axis C17, the axis C18, the axis C19, and the axis C20 are symmetric.

  The first short element 73O has substantially the same length as the first housing engaging element 73E. One end portion in the longitudinal direction of the first short element 73O is an intermediate portion between the shaft C19 and the shaft and C22, and is pivotally engaged with the second long element 73B with the shaft C21 as the rotation center. ing. The second short element 73P is formed in the same shape as the first short element 73O, and the first short element 73O with respect to the center plane (a plane that includes the axis C1 and is orthogonal to the U axis) It is symmetrical.

  The second short element 73P rotates with respect to the fourth long element 73D with the axis C41 as the rotation center. Further, the other end portion in the longitudinal direction of the first short element 73O and the other end portion in the longitudinal direction of the second short element 73P are engaged with each other so as to rotate around the axis C23. ing.

  Further, the distance between the axis C21 and the axis C23, the distance between the axis C23 and the axis C41, the distance between the axis C41 and the axis C22, and the distance between the axis C22 and the axis C21 are: , Each other is equal. Furthermore, each of the axes C15 to C23 and C35 to C41 extends in the W-axis direction.

  The link device 75 may have a configuration in which each of the medium length elements 73G to 73N and each of the short length elements 73O and 73P are deleted.

  The work holding device 71 according to the second embodiment operates in substantially the same manner as the work holding device 39 according to the first embodiment (see FIGS. 15 to 16), and has substantially the same effect. In addition to the above effects, the work holding device 71 according to the second embodiment has the following effects.

  That is, according to the work holding device 71, the work holding unit position changing unit 45 causes the link device 75 in which each element 73 constitutes a limited chain, and the link device 75 to perform a limited motion, while the link device 75 has a predetermined motion. Since it is configured to include an actuator (one servota) 77 that holds the form, the configuration of the apparatus is simplified and weight-reduced compared to that including a plurality of linear guide bearings and actuators.

  Further, according to the work holding device 71, since the casing 79 of the actuator 77 is integrally installed on the robot arm 41, the work holding device 71 can be installed on the robot arm 41 with a simple configuration.

  In the above description, the casing 79 of the actuator 77 is installed integrally with the robot arm 41. However, as shown in FIG. 17, a plurality of (for example, four) connecting rods 89, a robot hand bracket 87, The workpiece holding device 71 may be installed on the robot arm 41 using

  In the configuration shown in FIG. 17, the robot hand bracket 87 is integrally installed on the robot arm 41 at the tip of the robot arm 41. Further, both ends of each connecting rod 89 are spherical bearings. That is, one end of each connecting rod 89 is joined to the robot hand bracket 87 by a spherical bearing. Each first connecting rod 89 is joined to the central portion of the first long element 73A by a spherical bearing, and each second connecting rod 89 is joined to the central portion of the second long element 73B by a spherical bearing. The third connecting rod 89 is joined to the center of the third long element 73C by a spherical bearing, and the fourth connecting rod 89 is joined to the fourth long element by a spherical bearing. Each connecting rod 89 joined to the center of 73D is located at the hypotenuse of the equilateral leg pyramid.

  In the configuration shown in FIG. 17, the work holding device 71, each connecting rod 89, and the robot hand bracket 87 do not form a limited chain. Therefore, it is assumed that a mechanism (not shown) for limiting the work holding device 71, each connecting rod 89, and the robot hand bracket 87 is provided in the configuration shown in FIG. By providing this mechanism, when viewed from the W-axis direction, the center of the work holding device 71 and the center of the robot hand bracket 87 always coincide with each other, and the work holding device 71 is centered on the W axis. It is assumed that the workpiece holding device 7171 moves only in the W-axis direction without changing this posture in accordance with the rotation of the driving body 81 without rotating with respect to 87.

39, 77 Work holding device 41 Robot arm 43 Work holding part 45 Work holding part position changing part 47 Grasping work holding part 49 Adsorption work holding part 51 Base body 53 First moving body 55 Second moving body 57, 77 Actuator 61 Fixed claw 65 Movable claw 73 Element 75 Link device 79 Housing 81 Driving body (male screw shaft)
83 Nut W Workpiece

Claims (6)

A plurality of work holding units for holding the work at a plurality of different parts of the work;
When the shape of the workpiece is changed by processing the workpiece, according to the change in the shape, a workpiece holding portion position changing unit that changes the position of each workpiece holding portion,
A work holding device characterized by comprising: The work holding apparatus according to claim 1,
The work holding unit position changing unit includes a link device in which each element forms a limited chain, and an actuator that moves the link device in a limited motion and holds a predetermined form of the link device. ,
Each workpiece holding part is supported by a link of the link device. The work holding apparatus according to claim 2,
The actuator includes a housing and a driving body that drives the housing,
Some elements of each element constituting the link device are paired with the casing, and some other elements of the elements constituting the link device are Making a kinematic pair with the driver,
A work holding device, wherein a housing of the actuator is configured to be installed integrally with a robot arm. In the workpiece holding device according to any one of claims 1 to 3,
At least two work holding parts of the plurality of work holding parts are constituted by gripping work holding parts that hold and hold the work,
A first gripping work holding part which is one gripping work holding part among the gripping work holding parts, and a second gripping work holding part which is another one gripping work holding part among the gripping work holding parts. And a workpiece holding unit other than the gripping workpiece holding unit is located between
The work holding unit position changing unit changes a distance between the first holding work holding unit and the second holding work holding unit. A base body formed in a flat plate shape;
A first moving body that is formed in a flat plate shape and is movable and positionable in a direction approaching / separating from the base body on one side in a direction orthogonal to the thickness direction of the base body;
A second movable body that is formed in a flat plate shape and is movable and positionable in a direction approaching / separating from the base body on the other side in one direction orthogonal to the thickness direction of the base body;
An actuator for moving each movable body relative to the base body;
It is composed of at least one of a vacuum suction pad and a magnet, and one or more are provided on the base body, one or more are provided on the first moving body, and one or more are provided on the second moving body. A suction work holding part,
A fixed claw and a movable claw movable in a direction approaching / separating from the fixed claw, the end of the first moving body located on the side opposite to the base body, A gripping work holding part provided on an end of the second moving body located on the opposite side of the base body;
A work holding device characterized by comprising: An actuator including a housing and a male screw shaft that projects from the housing and rotates with respect to the housing around a predetermined axis;
A nut screwed into the male screw shaft;
A first elongate element having one end in the longitudinal direction engaged with the nut in a twisted pair;
The first elongate element is formed shorter than the first elongate element, and one end portion in the longitudinal direction forms a pair and engages the housing of the actuator, and the other end portion in the longitudinal direction forms a pair and forms the first pair. A first housing engaging element engaged with the first long element at an intermediate portion in the longitudinal direction of the long element;
A second elongate element having a longitudinal intermediate portion engaged with the first elongate element at a longitudinal intermediate portion of the first elongate element in a twisted pair;
A third elongate element formed in the same length as the first elongate element and having one end in the longitudinal direction engaged with the nut in a pair of turns;
It is formed to have the same length as the first housing engaging element, and one end in the longitudinal direction is engaged with the housing of the actuator by making a pair, and the other end in the longitudinal direction is formed by a pair. A second housing engaging element engaged with the third long element at an intermediate portion in the longitudinal direction of the third long element;
It is formed in the same length as the second long element, and the middle part in the longitudinal direction is engaged with the third long element at the middle part in the longitudinal direction of the third long element in a pair of turns. A fourth elongate element having one end in the longitudinal direction engaged with the first elongate element at one end in the longitudinal direction of the first elongate element in a twisted pair.
A plurality of workpiece holding portions provided integrally with each of the long elements;
A work holding device characterized by comprising: