Precision shearing process

  • Inventors:
  • Assignees: Kondo K
  • Publication Date: September 26, 1973
  • Publication Number: GB-1331645-A


1331645 Punching K KONDO 13 Nov 1970 [15 Nov 1969] 54202/70 Heading B3W In a precision shearing method which uses a punch and a die, of which one is of conventional design and the other is stepped to form clearances relative to said one tool which are positive, and negative or substantially zero, one of the tools is urged towards the work thereby causing first the positive, and then the negative or substantially zero, clearance to act on a workpiece, the process being completed without allowing the punch to enter the die to a distance greater than the height of the stepped portion. For blanking of discs from a plate the step 6 is formed on the punch; for punching, the step is on the die. Instead of the right-angled step shown the step may be inclined to the stepped position at 45 degrees. The step need not be continuous but may be provided only at sharp cornered convex parts where fracture cracks would be likely to develop. The stepped punch or die may be used in combination with conventional fine blanking techniques of clamping a workpiece around the cut using a knife edge on a pressure plate and rounding the tool edges.




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    CN-103143612-AJune 12, 2013北京机电研究所Smooth and clean fine blanking mould
    CN-103143612-BFebruary 25, 2015北京机电研究所光洁精冲模具
    GB-2218661-ANovember 22, 1989Sonny SneedPunching tool