Press-Hardened Shaped Metal Sheet Having Different Sheet Thicknesses and Strengths

Abstract

A press-hardened shaped metal sheet has at least two adjacent zones having different sheet thicknesses and different strengths such that one of the zones is press-hardened and the other zone is non-hardened or only slightly hardened. A transition zone, which is simultaneously designed as a thickness transition zone and as a strength transition zone, is located between the zones. The press-hardened shaped metal sheet is preferably a pillar reinforcement for a motor vehicle body.

Claims

1. A press-hardened shaped metal sheet which has different sheet thicknesses and strengths, comprising: at least two adjacent zones of the shaped metal sheet formed with different sheet thicknesses and with different strengths, such that one of these zones is press-hardened and the other zone is non-hardened or only slightly hardened, and a transition zone configured as a thickness transition zone and as a strength transition zone formed between the two adjacent zones.

2. The shaped metal sheet as claimed in claim 1, wherein the shaped metal sheet is produced from a tailored rolled blank.

3. The shaped metal sheet as claimed in claim 1, wherein the transition zone has a width of 20 mm to 60 mm.

4. The shaped metal sheet as claimed in claim 1, wherein the transition zone has a width of 40 mm to 50 mm.

5. The shaped metal sheet as claimed in claim 1, wherein the one zone of the two adjacent zones having the greater sheet thickness is press-hardened.

6. The shaped metal sheet as claimed in claim 1, further comprising: a metallic anti-corrosion coating on the shaped metal sheet.

7. The shaped metal sheet as claimed in claim 3, wherein the one zone of the two adjacent zones having the greater sheet thickness is press-hardened.

8. The shaped metal sheet as claimed in claim 7, further comprising: a metallic anti-corrosion coating on the shaped metal sheet.

9. A pillar reinforcement formed as a press-hardened shaped metal sheet for a motor vehicle body, comprising: a press-hardened central zone and an adjacent non-hardened or only slightly hardened bottom zone, which are formed with different sheet thicknesses; and a transition zone configured as a thickness transition zone and as a strength transition zone, formed between the press-hardened central zone and the bottom zone.

10. The pillar reinforcement as claimed in claim 9, wherein the pillar reinforcement is a B-pillar reinforcement.

11. The pillar reinforcement as claimed in claim 9, wherein the transition zone has a width of 20 mm to 60 mm.

12. The pillar reinforcement as claimed in claim 9, wherein the transition zone has a width of 40 mm to 50 mm.

13. The pillar reinforcement as claimed in claim 11, wherein the press-hardened central zone has a greater sheet thickness than the adjacent non-hardened or only slightly hardened bottom zone.

14. The pillar reinforcement as claimed in claim 13, further comprising a metallic anti-corrosion coating on the pillar reinforcement.

15. The pillar reinforcement as claimed in claim 9, wherein the press-hardened central zone has a plurality of sub-zones with different sheet thicknesses, wherein these sub-zones are formed with a substantially equal strength.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0022] FIG. 1 is a plan view of a pillar reinforcement for a passenger motor vehicle body.

[0023] FIG. 2 is an enlarged sectional illustration showing the transition zone between the bottom zone and the central zone on the pillar reinforcement from FIG. 1.

DETAILED DESCRIPTION OF THE DRAWINGS

[0024] FIG. 1 shows a pillar reinforcement (inner pillar) 100 for a B pillar. The pillar reinforcement is formed as a press-hardened shaped metal sheet which has zones with different sheet thicknesses and different strengths, by which means a shape both matching the stress and matching the requirements (the requirements are different in the different zones), and also a weight-optimized configuration, is achieved. The pillar reinforcement 100 is produced from a single rolled tailored blank.

[0025] In the example shown, the pillar reinforcement 100 has a press-hardened central zone 110 in which the sheet material has a strength of, for example, at least 1300 MPa achieved by press hardening. The central zone 110 includes a plurality of substantially equally strong (i.e. formed with equal strength) sections or sub-zones with different sheet thickness. The sub-zone 111 at the top has a sheet thickness of 2.3 mm, for example. The central sub-zone 112 has a sheet thickness of 2.5 mm, for example. And, the bottom sub-zone 113 has a sheet thickness of 2.3 mm, for example. The transitions are formed as continuous transitions, i.e. without sheet thickness jumps. The pillar reinforcement 100 also has a bottom zone 130, in which the sheet material is only slightly hardened or non-hardened and is thus soft and, for example, has a strength of 450 MPa to 800 MPa. The sheet thickness in the bottom zone 130 is, for example, 1.9 mm. The pillar reinforcement 100 also has a top zone 120, in which the sheet material is likewise press-hardened, and, just like the central zone 110, has a strength of, for example, at least 1300 MPa. The sheet thickness in the top zone 120 is, for example, 1.9 mm.

[0026] The pillar reinforcement 100 is thus designed to be particularly thick and particularly strong in the central zone 110, on which particularly high strength and stiffness requirements are placed (for example because of occupant protection and because of the attachment of door hinges and door locks). In the bottom zone 130, which is provided for the attachment of the pillar reinforcement 100 to a side sill or the like, specific deformation (for example bending inward) is made possible by the less strong or softer sheet material in the event of a crash, and tears and brittle fractures are prevented.

[0027] According to the invention, between the press-hardened central zone 110 and the soft bottom zone 130, these zones also having different sheet thicknesses, there is formed a transition zone 140, which is configured not only as a thickness transition zone but also as a strength transition zone. The transition zone of the strength thus corresponds substantially to the transition zone of the sheet thickness. Along the transition zone 140, the central zone 110 or its sub-zone 113 and the bottom zone 130 are delimited with respect to each other or merge into one another in the transition zone 140.

[0028] The strip-like transition zone 140 is illustrated in FIG. 2 in an enlarged sectional illustration. Within this transition zone 140, the strength of the sheet material changes gradually from 450 MPa to 800 MPa (in the bottom zone 130) to a strength of at least 1300 MPa (in the central zone 110 or in its sub-zone 113 at the bottom) or rises appropriately. Likewise, within this transition zone 140, the sheet thickness rises gradually and thus without steps or jumps from 1.9 mm to 2.3 mm (from the bottom zone 130 to the sub-zone 113 at the bottom).

[0029] The transition zone 140 preferably has a width B of 20 mm to 60 mm and, in particular, of 40 mm to 50 mm. The transition zone 140 can also have a variable width B, which means a width that varies over the course (according to FIG. 1).

[0030] The invention offers the advantages that the properties of a press-hardened shaped metal sheet according to the invention, above all at the transition points between zones with different strengths and sheet thicknesses, are formed very precisely, and that the quality-reproducing production is possible with comparative little outlay on tool configuration and working-in.

[0031] List of designations

TABLE-US-00001 Press-hardened shaped metal sheet with different sheet thicknesses and strengths 100 Pillar reinforcement (shaped metal sheet) 110 Central zone 111 Sub-zone 112 Sub-zone 113 Sub-zone 120 Top zone 130 Bottom zone 140 Transition zone B Width

[0032] The foregoing disclosure has been set forth merely to illustrate the invention and is not intended to be limiting. Since modifications of the disclosed embodiments incorporating the spirit and substance of the invention may occur to persons skilled in the art, the invention should be construed to include everything within the scope of the appended claims and equivalents thereof.