Core grasping method

{
  "publication_number": "US10059572B2",
  "country": "US",
  "kind": "B2",
  "title": "Core grasping method",
  "abstract": "Provided is a core grasping method of grasping a core using a core grasping apparatus. The core grasping apparatus includes grasping devices respectively having expandable and contractible grasping parts. The core includes holes, and at least one of the holes has an inside diameter that decreases in the opposite direction from a direction of a turning moment occurring on the core. The core grasping method involves, when grasping the core, expanding the grasping parts inserted in the holes so as to bring the grasping parts into contact with inner walls of the holes of the core, and grasping the core and applying a force that suppresses the turning moment to the core.",
  "claims": [
    "1. A core grasping method of grasping a core using a core grasping apparatus, the core grasping apparatus comprising a first grasping device having a first grasping part and a second grasping device having a second grasping part, the first grasping part and the second grasping part being expandable and contractible, the core being a core on which a turning moment occurs around a predetermined central axis upon being lifted up, and having a first hole and a second hole that are provided respectively on both sides of the core in a horizontal direction around the central axis and open in a vertical direction, at least one of the first hole and the second hole having an inside diameter that decreases in an opposite direction from a direction of the turning moment occurring on the core, the core grasping method comprising: moving the first grasping device and the second grasping device downward, and inserting the first grasping part and the second grasping part respectively into the first hole and the second hole with a driving unit motor; and expanding the first grasping part and the second grasping part with gas or liquid supplied to the first and second grasping parts so as to bring the first grasping part and the second grasping part respectively into contact with inner walls of the first hole and the second hole of the core, and grasping the core and applying a force that suppresses the turning moment to the core.",
    "2. The core grasping method according to claim 1, wherein both the first hole and the second hole have the inside diameter that decreases in the opposite direction from the direction of the turning moment, and the core grasping method comprises, when grasping the core, bringing the first grasping part and the second grasping part respectively into contact with the inner walls of the first hole and the second hole, and applying a force that suppresses the turning moment from the first grasping part and the second grasping part to the core.",
    "3. The core grasping method according to claim 2, wherein the core is placed on a platform, the first hole has the inside diameter that decreases in a direction away from the platform, the second hole has the inside diameter that decreases in a direction toward the platform, and the core grasping method comprises, when grasping the core, expanding the second grasping part before the first grasping part to grasp the core.",
    "4. The core grasping method according to claim 3, wherein when grasping the core, expanding the first grasping part at a lower pressure than the second grasping part.",
    "5. The core grasping method according to claim 1, wherein at least one of the first hole and the second hole has the inside diameter that decreases from a portion at or near a center of the hole in the vertical direction toward each of an upper opening and a lower opening of the hole."
  ],
  "description_excerpt": "1. Technical Field\n\nThe present disclosure relates to a core grasping method.\n\n2. Description of Related Art\n\nA casting core is a mold that is used to form a hollow inside a cast article to be produced. Conventionally, cores are manually placed inside dies. In recent years, however, the increasing accuracy of cast articles has made it increasingly important to dispose cores inside dies with high accuracy. Accordingly, it is more important than ever to develop a technique for disposing cores inside dies with high accuracy.\n\nPublished Japanese Translation of PCT application No. 05-509071 discloses a technique related to a conveyor that conveys casting cores.\n\nAmong existing methods of grasping a core is a method of grasping a core using a picker (grasping device) that has an expandable and contractible grasping part at a leading end. In this method, a core is grasped by inserting the grasping part of the picker into a hole formed in the core and expanding the grasping part so as to fix the picker to the hole of the core.\n\nHowever, depending on the shape of the core, a turning moment occurs on the core around a predetermined central axis. Thus, when the core is grasped by inserting the grasping part of the picker into the hole of the core and expanding the grasping part, the core inclines upon being lifted up as a turning moment acts thereon around a predetermined central axis, which results in lower positional accuracy in disposing the core.\n\nThe present disclosure provides a core grasping method that can improve the positional accuracy in disposing a core.",
  "cpc": [
    "B66C 1/46",
    "B22C 23/00",
    "B25J 15/00",
    "B25J 15/0047",
    "H10P 72/76",
    "H10P 72/7604",
    "H10P 95/00"
  ],
  "ipc": [
    "B22C 23/00",
    "B25J 15/00",
    "B66C 1/46"
  ],
  "assignees": [
    "Toyota Motor Corp"
  ],
  "inventors": [
    "Yoshitaka Tanaka",
    "Makoto Kikuchi",
    "Tsubasa Ito",
    "Mitsuhiro ISHIKURA",
    "Masaki KOBUNE"
  ],
  "filing_date": "2017-09-25",
  "publication_date": "2018-08-28",
  "grant_date": "2018-08-28",
  "priority_date": "2016-10-14",
  "application_number": "US-201715714392-A",
  "family_id": "60117478",
  "cited_by_count": 0,
  "citations": [
    "JPH05509071A",
    "US5425441A",
    "US20120291872A1",
    "US20150239130A1",
    "US20150239129A1",
    "US20160068372A1",
    "US20170253357A1",
    "US20180104782A1"
  ]
}