Molding method for plate-shaped workpiece, and molded article

Patent metadata

Field	Value
Publication number	US-9616479-B2
Application number	US-201113635476-A
Country	US
Kind code	B2
Filing date	Mar 18, 2011
Priority date	Mar 18, 2010
Publication date	Apr 11, 2017
Grant date	Apr 11, 2017

Abstract

Provided is a molding method for a plate-shaped workpiece including forming a concave portion ( 11 ) at one surface ( 1 a ) of a plate-shaped workpiece ( 1 ), and bending the plate-shaped workpiece ( 1 ) having the concave portion ( 11 ) such that the one surface ( 1 a ) becomes a concave surface and a rear surface ( 1 b ) thereof becomes a convex surface.

First claim

The invention claimed is:

1. A molding method for a plate-shaped workpiece comprising a first surface and a second surface, the first surface formed of a flat surface, and a second surface positioned opposite to the first surface on the plate-shaped workpiece and formed of a flat surface, the molding method comprising:
forming a concave portion at the first surface of the plate-shaped workpiece, wherein the plate-shaped workpiece is one piece;
forming a first stepped portion at a corner of the first surface side of the concave portion, wherein the first stepped portion has a stepped shape;
inserting a shim formed with a second stepped portion and formed of a material having a lower Young's modulus than that of the plate-shaped workpiece into the concave portion so that at least a portion of the first stepped portion is engaged with the second stepped portion; and
pressing the plate-shaped workpiece against a mold member to perform bending processing, wherein a shape of the first surface becomes a concave surface shape.

2. The molding method for a plate-shaped workpiece according to claim 1 , wherein the plate-shaped workpiece is bent by press or roll bending such that the second surface becomes a convex surface shape.

3. The molding method for a plate-shaped workpiece according to claim 1 , wherein the concave portion comprises a plurality of concave portions formed at the first surface of the plate-shaped workpiece at predetermined intervals.

4. The molding method for a plate-shaped workpiece according to claim 1 , wherein the concave portion comprises a plurality of concave portions, and the shim comprises a plurality of shims having a shape corresponding to the plurality of concave portions, respectively.

5. The molding method for a plate-shaped workpiece according to claim 4 , wherein the plurality of shims are formed so as to be slightly smaller than an inner hole dimension of the plurality of concave portions, respectively.

6. The molding method for a plate-shaped workpiece according to claim 4 , wherein the plurality of shims are formed of phenol resin having a Young's modulus of 7 to 10 GPa.

7. The molding method for a plate-shaped workpiece according to claim 1 , wherein, as a tensile force is applied to the plate-shaped workpiece while the mold member abuts the first surface of the plate-shaped workpiece, the plate-shaped workpiece is bent such that the second surface becomes a convex surface shape.

8. The molding method for a plate-shaped workpiece according to claim 7 , wherein the concave portion comprises a plurality of concave portions formed at the first surface of the plate-shaped workpiece at predetermined intervals.

9. The molding method for a plate-shaped workpiece according to claim 7 , wherein the concave portion comprises a plurality of concave portions, and the shim comprises a plurality of shims having a shape corresponding to the plurality of concave portions, respectively.

10. The molding method for a plate-shaped workpiece according to claim 7 , wherein the plate-shaped workpiece having the concave portion is formed such that a first ratio of a maximum cross-sectional area of the workpiece in a tensile direction divided by a minimum cross-sectional area of the workpiece in the tensile direction is less than or equal to a second ratio of tensile strength divided by proof stress of a material which forms the workpiece.

11. A molded article manufactured by the molding method for a plate-shaped workpiece according to claim 1 .

12. The molding method for a plate-shaped workpiece according to claim 2 , wherein the concave portion comprises a plurality of concave portions formed at the first surface of the plate-shaped workpiece at predetermined intervals.

13. The molding method for a plate-shaped workpiece according to claim 2 , wherein the concave portion comprises a plurality of concave portions, and the shim comprises a plurality of shims having a shape corresponding to the plurality of concave portions, respectively.

14. The molding method for a plate-shaped workpiece according to claim 3 , wherein the concave portion comprises a plurality of concave portions, and the shim comprises a plurality of shims having a shape corresponding to the plurality of concave portions, respectively.

15. The molding method for a plate-shaped workpiece according to claim 12 , wherein the shim comprises a plurality of shims having a shape corresponding to the plurality of concave portions, respectively.

16. The molding method for a plate-shaped workpiece according to claim 13 , wherein the plurality of shims are formed so as to be slightly smaller than an inner hole dimension of the plurality of concave portions, respectively.

17. The molding method for a plate-shaped workpiece according to claim 14 , wherein the plurality of shims are formed so as to be slightly smaller than an inner hole dimension of the plurality of concave portions, respectively.

18. The molding method for a plate-shaped workpiece according to claim 15 , wherein the plurality of shims are formed at a minus tolerance slightly smaller than an inner hole dimension of the plurality of concave portions, respectively.

19. The molding method for a plate-shaped workpiece according to claim 5 , wherein the plurality of shims are formed of phenol resin having a Young's modulus of 7 to 10 GPa.

Assignees

• Ota Takahiro
• Ogura Daisuke
• Sugai Atsushi
• Ishii Ken
• Mitsubishi Heavy Ind Ltd

Inventors

• Ota Takahiro
• Ogura Daisuke
• Sugai Atsushi
• Ishii Ken

Classifications

• B21D11/08 Primary

  Bending by altering the thickness of part of the cross-section of the work (B21D11/06 takes precedence) · CPC title

• B21D11/206

  Curving corrugated sheets · CPC title

• B21D11/02

  Bending by stretching or pulling over a die (working sheet metal of limited length by stretching B21D25/00) · CPC title

• Y10T428/1241

  Nonplanar uniform thickness or nonlinear uniform diameter [e.g., L-shape] · CPC title