Magneto-repulsion punching with dynamic damping
US5726568A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 7, 1995 |
| Grant date | Mar 10, 1998 |
| Priority date | — |
| Expiry date | Jun 7, 2015 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T83/8765
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
Dimpling of a workpiece by rebounding of a magnetic repulsion punch mechanism, when operated at high punching rates, is avoided by application of a damping pulse at a point at or subsequent to a mid-point of a return stroke of the punch from the workpiece and preferably within the last 10% of the return stroke. This damping pulse is preferably a fraction of the pulse width and of approximately the same amplitude as a driving pulse applying kinetic energy to the punch for causing punching of the workpiece. At high punching rates the kinetic energy of the return portion of a punching stroke is substantially determined by elastic rebounding of the punch from a guide bushing. The removal of kinetic energy during the return portion of the stroke allows the return of the punch to a position close to a rest position during a very short interval with small overshoot under control of mechanical damping. Since dynamic damping may be substituted for much of the mechanical damping in the punching arrangement, high quality punching may be accomplished at much increased punching rates. A preferred form of monitoring punch position employs RF reflected inductance and may be used to form a time ex…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.