Method for the production of high-precision half shells with high dimensional precision

• US 20090255317A1
• Filed: 04/06/2009
• Published: 10/15/2009
• Est. Priority Date: 04/11/2008
• Status: Active Grant

• Current Assignee: thyssenkrupp Steel Europe AG (Thyssenkrupp AG)
• Original Assignee: thyssenkrupp Steel Europe AG (Thyssenkrupp AG)
• Inventors: Flehmig, Thomas, Savvas, Konstantinos
• Granted Patent: US 8,240,184 B2
• Time in Patent Office: Days
• US Class Current: 72/348
• CPC Class Codes: B21D 13/00 Corrugating sheet metal, rods or profiles; Bending sheet metal, rods or profiles into wave form tubes B21D15/00
• CPC Class Codes: B21D 22/201 Work-pieces; preparation of the work-pieces, e.g. lubricating, coating
• CPC Class Codes: B21D 22/22 with devices for holding the edge of the blanks B21D22/24 - B21D22/30 take precedence; shaping over a die without external former B21D11/02

Abstract

A method for converting blanks by drawing in a tool with a ram, a die and a pressure pad wherein, converted blanks with high dimensional precision can be produced, includes feeding a blank with a plurality of bulges to the tool. In flange regions of the blank the pressure pad is moved in a first process step of the method into a first position, which corresponds to the height of the bulges of the flange region of the blank added to the blank thickness. In the first process step the blank is preformed in the tool using the ram and in a second process step the pressure pad and the ram are moved into the end positions, so that the blank is converted by the ram to the end form and the pressure pad smoothes the bulges of the flange regions of the blank.

Claims

1. Method for converting blanks by drawing in a tool with a ram, a die and a pressure pad, wherein a blank with a plurality of bulges is fed to a tool, in flange regions of the blank the pressure pad is moved in a first process step into a first position which corresponds to the height of the bulges of the flange region of the blank added to the blank thickness, the pressure pad holds the flange regions of the blank down in the first position, in the first process step the blank is preformed in the tool using the ram and in a second process step the pressure pad and the ram are moved into end positions, so that the blank is converted by the ram to an end form and the pressure pad smoothes the bulges of the flange regions of the blank.

2. Method according to claim 1, wherein during the first process step the bulges persist in the preformed blank and in the second process step first the pressure pad and afterwards the ram are moved into the end positions, so that the bulges are smoothed first in the region of the pressure pad and then in a remaining region.

3. Method according to claim 1, wherein the blank consists of steel.

4. Method according to claim 1, wherein in the first process step the bulges are flattened in inlet regions of the ram between flange and notches.

5. Method according to claim 1, wherein the ram of the tool has an extension towards a drawing radius, which produces the drawing radius on a drawn component in the second process step.

6. Method according to claim 1, wherein in the first process step a gap is created in the region of notches, which is greater than or equal to the height of the bulges added to the blank thickness.

7. Method according to claim 1, wherein in a final shaping a gap between blank and tool is about zero.

8. Method according to claim 1, wherein a surface of the blank, which is provided with the bulges is 0.1-10% greater than that of an even blank.

9. Method according to claim 1, wherein burls with a circular, elliptical, multi-angular and/or elongated opening surface are provided as the bulges.

10. Method according to claim 1, wherein the bulges on the blank are arranged in such a manner that equally distributed, even spacings develop on the blank between the bulges.

11. (canceled)