Workpiece conveying system, conveyed workpiece number detector, and control method for the workpiece conveying system

{
  "publication_number": "US11554492B2",
  "country": "US",
  "kind": "B2",
  "title": "Workpiece conveying system, conveyed workpiece number detector, and control method for the workpiece conveying system",
  "abstract": "Provided is a workpiece conveying system configured to convey a sheet-like workpiece to a downstream step, including: a workpiece conveyor configured to lift through attraction holding, by a workpiece holding unit, an uppermost workpiece W of a stack, and convey the uppermost workpiece W of the stack to the downstream step one by one; and a conveyed workpiece number detector configured to detect the number of workpieces W held by the workpiece holding unit at a detection timing, at which the workpiece W held and raised by the workpiece holding unit in accordance with a normal workpiece conveying operation performed by the workpiece conveyor reaches an upper limit position of raising the workpiece W, and at which a moving speed component of the workpiece W in a raising direction is 0.",
  "claims": [
    "1. A workpiece conveying system configured to convey a sheet-like workpiece to a downstream step, comprising: a workpiece conveyor configured to lift through attraction holding, by a workpiece holding unit, an uppermost workpiece of a stack stacking a plurality of workpieces, and to convey the uppermost workpiece of the stack to the downstream step one by one; a conveyed workpiece number detector configured to detect a number of workpieces held by the workpiece holding unit at a detection timing, at which the workpiece held and raised by the workpiece holding unit in accordance with a normal workpiece conveying operation performed by the workpiece conveyor reaches an upper limit position of raising the workpiece, and at which a moving speed component of the workpiece in a raising direction is 0; and a workpiece stopper configured to be brought into abutment against, at the upper limit position of raising the workpiece, a top surface of the workpiece held and raised by the workpiece holding unit.",
    "2. The workpiece conveying system according to claim 1, wherein at the detection timing, when the conveyed workpiece number detector detects that the number of workpieces held by the workpiece holding unit is one, the normal workpiece conveying operation is continued subsequently, and the workpiece is conveyed to a next step, and wherein at the detection timing, when the conveyed workpiece number detector detects that the number of workpieces held by the workpiece holding unit is multiple, the multiple workpieces are discharged into a collection box without being conveyed to the next step.",
    "3. The workpiece conveying system according to claim 1, wherein the conveyed workpiece number detector is configured to detect the number of workpieces held by the work piece holding unit based on data obtained by a camera or laser.",
    "4. A workpiece conveying system configured to convey a sheet-like workpiece to a downstream step, comprising: a workpiece conveyor configured to lift through attraction holding, by a workpiece holding unit, an uppermost workpiece of a stack stacking a plurality of workpieces, and to convey the uppermost workpiece of the stack to the downstream step one by one; a conveyed workpiece posture detector configured to detect a posture of workpiece held by the workpiece holding unit at a detection timing, at which the workpiece held and raised by the workpiece holding unit in accordance with a normal workpiece conveying operation performed by the workpiece conveyor reaches an upper limit position of raising the workpiece, and at which a moving speed component of the workpiece in a raising direction is 0; and a workpiece stopper configured to be brought into abutment against, at the upper limit position of raising the workpiece, a top surface of the workpiece held and raised by the workpiece holding unit.",
    "5. The workpiece conveying system according to claim 4, wherein at the detection timing, when the conveyed workpiece posture detector detects that the posture of the workpiece held by the workpiece holding unit is normal, the normal workpiece conveying operation is continued subsequently, and the workpiece is conveyed to a next step, and wherein at the detection timing, when the conveyed workpiece posture detector detects that the posture of the workpiece held by the workpiece holding unit is abnormal, the workpiece is conveyed to the next step while correcting the posture of the workpiece to a normal posture.",
    "6. The workpiece conveying system according to claim 4, further comprising a conveyed workpiece number detector configured to detect the number of workpieces held by the work piece holding unit based on data obtained by a camera or laser.",
    "7. A workpiece conveying system configured to convey a sheet-like workpiece to a downstream step, comprising: a workpiece conveyor configured to lift through attraction holding, by a workpiece holding unit, an uppermost workpiece of a stack stacking a plurality of workpieces, and to convey the uppermost workpiece of the stack to the downstream step one by one; a conveyed workpiece number detector configured to detect a number of workpieces held by the workpiece holding unit at a detection timing, at which the workpiece held and raised by the workpiece holding unit in accordance with a normal workpiece conveying operation performed by the workpiece conveyor reaches an upper limit position of raising the workpiece, and at which a moving speed component of the workpiece in a raising direction is 0; a conveyed workpiece posture detector configured to detect a posture of the workpiece held by the workpiece holding unit at the detection timing, at which the workpiece held and raised by the workpiece holding unit in accordance with the normal workpiece conveying operation performed by the workpiece conveyor reaches the upper limit position of raising the workpiece, and at which the moving speed component of the workpiece in the raising direction is 0; and a workpiece stopper configured to be brought into abutment against, at the upper limit position of raising the workpiece, a top surface of the workpiece held and raised by the workpiece holding unit.",
    "8. The workpiece conveying system according to claim 7, wherein at the detection timing, when the conveyed workpiece number detector detects that the number of workpieces held by the workpiece holding unit is one, and the conveyed workpiece posture detector detects that the posture of the workpiece held by the workpiece holding unit is normal, the normal workpiece conveying operation is continued subsequently, and the workpiece is conveyed to a next step, wherein at the detection timing, when the conveyed workpiece number detector detects that the number of workpieces held by the workpiece holding unit is one, and the conveyed workpiece posture detector detects that the posture of the workpiece held by the workpiece holding unit is abnormal, the workpiece is conveyed to the next step while correcting the posture of the workpiece to a normal posture, and wherein at the detection timing, when the conveyed workpiece number detector detects that the number of workpieces held by the workpiece holding unit is multiple, the multiple workpieces are discharged into a collection box without being conveyed to the next step.",
    "9. The workpiece conveying system according to claim 7, wherein the conveyed workpiece number detector is configured to detect the number of workpieces held by the work piece holding unit based on data obtained by a camera or laser.",
    "10. A conveyed workpiece number detector, which is provided in a workpiece conveying system configured to lift through attraction holding, by a workpiece holding unit, an uppermost workpiece of a stack stacking a plurality of workpieces, and to convey the uppermost workpiece of the stack to a downstream step one by one, the conveyed workpiece number detector comprising: a detector configured to detect the number of workpieces held by the workpiece holding unit at a detection timing, at which the workpiece held and raised by the workpiece holding unit in accordance with a normal workpiece conveying operation performed by the workpiece conveying system reaches an upper limit position of raising the workpiece, and at which a moving speed component of the workpiece in a raising direction is 0, and a workpiece stopper configured to be brought into abutment against, at the upper limit position of raising the workpiece, a top surface of the workpiece held and raised by the workpiece holding unit.",
    "11. The workpiece conveying system according to claim 10, wherein the conveyed workpiece number detector is configured to detect the number of workpieces held by the work piece holding unit based on data obtained by a camera or laser.",
    "12. A control method for a workpiece conveying system configured to lift through attraction holding, by a workpiece holding unit, an uppermost workpiece of a stack stacking a plurality of workpieces, and to convey the uppermost workpiece of the stack to a downstream step one by one, the control method comprising: detecting the number of workpieces held by the workpiece holding unit at a detection timing, at which the workpiece held and raised by the workpiece holding unit in accordance with a normal workpiece conveying operation performed by the workpiece conveying system reaches an upper limit position of raising the workpiece, and at which a moving speed component of the workpiece in a raising direction is 0; continuing, subsequently, the normal workpiece conveying operation to convey the workpiece to a next step when the detection result is that the number of workpieces held by the workpiece holding unit is one; discharging a plurality of workpieces into a collection box without conveying the plurality of workpieces to the next step when the detection result is that the number of workpieces held by the workpiece holding unit is multiple; and bringing a workpiece stopper into abutment against, at the upper limit position of raising the workpiece, a top surface of the workpiece held and raised by the workpiece holding unit.",
    "13. A control method for a workpiece conveying system configured to lift through attraction holding, by a workpiece holding unit, an uppermost workpiece of a stack stacking a plurality of workpieces, and to convey the uppermost workpiece of the stack to a downstream step one by one, the control method comprising: detecting the number of workpieces and a posture of the workpiece held by the workpiece holding unit at a detection timing, at which the workpiece held and raised by the workpiece holding unit in accordance with a normal workpiece conveying operation performed by the workpiece conveying system reaches an upper limit position of raising the workpiece, and at which a moving speed component of the workpiece in a raising direction is 0; continuing, subsequently, the normal workpiece conveying operation to convey the workpiece to a next step when the detection result is that the number of workpieces held by the workpiece holding unit is one, and the posture of the workpiece held by the workpiece holding unit is normal; conveying the workpiece to the next step while correcting the posture of the workpiece to a normal posture when the detection result is that the number of workpieces held by the workpiece holding unit is one and the posture of the workpiece held by the workpiece holding unit is abnormal; discharging a plurality of workpieces into a collection box without conveying the plurality of workpieces to the next step when the detection result is that the number of workpieces held by the workpiece holding unit is multiple; and bringing a workpiece stopper into abutment against, at the upper limit position of raising the workpiece, a top surface of the workpiece held and raised by the workpiece holding unit."
  ],
  "description_excerpt": "The present invention relates to a technology of improving a workpiece conveying system configured to successively take a sheet-like member from a top of a stack (bunch) stacking a plurality of sheet-like workpieces one by one, and to convey the sheet-like member to, for example, a pressing machine in a next step (downstream step).\n\nHitherto, as a technology of feeding a sheet-like workpiece (thin-plate-like workpiece) of this kind to the pressing machine, for example, in Japanese Patent Application Laid-open No. 2014-172047, a workpiece conveying system as illustrated in FIG. 9 is described. The workpiece conveying system refers to a system configured to take a workpiece from a top of a bunch-like sheet group (bunch (stack) stacking a plurality of sheet-like workpieces) one by one, and convey (feed) the workpiece to a next step (for example, to the pressing machine).\n\nIncidentally, when the sheet-like workpieces W are stacked, the upper and lower workpieces W closely attract (or adhere) to each other due to, for example, an oil attracting (or adhering) to surfaces of the workpieces W. Thus, when an uppermost workpiece W is intended to be lifted and conveyed, in some cases, a workpiece W directly below the uppermost workpiece W is also lifted together. This is what is called a state in which two workpieces (or double workpieces) are taken. When the workpieces W are set to, for example, the pressing machine in the next step under the state in which the two workpieces are taken, various troubles are caused.",
  "cpc": [
    "B21D 43/24",
    "B21D 43/021",
    "B21D 43/26",
    "B25J 15/008",
    "B25J 9/1694",
    "B65G 59/04"
  ],
  "ipc": [
    "B21D 43/02",
    "B25J 15/00",
    "B25J 9/16",
    "B65G 59/04"
  ],
  "assignees": [
    "Aida Engineering Ltd"
  ],
  "inventors": [
    "Keisuke Takeda",
    "Satoshi Suzuki"
  ],
  "filing_date": "2020-01-09",
  "publication_date": "2023-01-17",
  "grant_date": "2023-01-17",
  "priority_date": "2019-01-24",
  "application_number": "US-202016738860-A",
  "family_id": "69185409",
  "cited_by_count": 0,
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    "JP2008093698A",
    "US20080277860A1",
    "EP2177326A2",
    "US8961094B2",
    "JP2014172047A",
    "JP2014155965A",
    "US20180002118A1"
  ]
}