Hot-formed metal sheet and method of producing an opening in such a metal sheet

Abstract

A hot-formed metal sheet has a tensile strength Rm>1300 megapascal (MPa) and includes an opening which is produced by high-speed punching at a speed of a punch of more than 6 m/s in the absence of a counter holder of a contour matching a contour of the punch, with a smooth cut proportion of the cutting surface of the opening amounting to more than 50%.

Claims

1. A method, comprising: hot forming and press hardening a metal sheet in a press-hardening tool to a tensile strength of Rm >1300 megapascal (MPa); and producing an opening with closed cutting line in the hot formed and press hardened metal sheet at the tensile strength Rm solely by high-speed punching the metal sheet in a single-step process with a punch at a speed of the punch of more than 6 m/s, sufficient to cause a momentary temperature rise in immediate proximity of the opening to at least minimize strain hardening and wherein the producing step is performed without the use of a counter holder.

2. The method of claim 1, wherein the speed of the punch is less than 100 m/s and greater than 10 m/s.

3. The method of claim 1, wherein the speed of the punch is less than 100 m/s and greater than 20 m/s.

4. The method of claim 1, further comprising mounting the punch to a robotic arm for movement of the punch into a work position in relation to the metal sheet.

5. The method of claim 4, further comprising securing the metal sheet to the robotic arm or to a further robotic arm in relation to the punch in the work position.

Description

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

(1) NONE

(2) While the invention has been illustrated and described in connection with currently preferred embodiments described in detail, it is not intended to be limited to the details described since various modifications and structural changes may be made without departing in any way from the spirit and scope of the present invention. The embodiments were chosen and described in order to explain the principles of the invention and practical application to thereby enable a person skilled in the art to best utilize the invention and various embodiments with various modifications as are suited to the particular use contemplated.

(3) What is claimed as new and desired to be protected by Letters Patent is set forth in the appended claims and includes equivalents of the elements recited therein: