{
  "$type": "site.standard.document",
  "description": "A method of press-forming a tubular part having a cross section of an irregular shape crushes a steel tube between an upper die and a lower die in order to form a V-shaped cross section. When the curvature radius of a tip of the upper die is defined as R 1 , the curvature radius of a bottom portion…",
  "path": "/patents/1014812",
  "publishedAt": "2011-03-23T00:00:00.000Z",
  "site": "at://did:plc:oql6ds5vnff4ugar6rruliwd/site.standard.publication/3mn3ohu7oxx5w",
  "tags": [
    "B21D22/025",
    "NIPPON STEEL CORP [JP]"
  ],
  "textContent": "A method of press-forming a tubular part having a cross section of an irregular shape crushes a steel tube between an upper die and a lower die in order to form a V-shaped cross section. When the curvature radius of a tip of the upper die is defined as R 1 , the curvature radius of a bottom portion of the lower die corresponding to the tip of the upper die is defined as R 2 , and the wall thickness of the steel tube is defined as t; R 1 , R 2 , and t satisfy R 1 +2t=R 2 and 1.5t¤R 1 ¤3t.",
  "title": "PRESS-FORMING METHOD OF TUBULAR PART HAVING CROSS-SECTION OF IRREGULAR SHAPE"
}