Method of Drawing a Blank by Preforming a Channel in a Preform that is Subsequently Drawn into a Die Cavity

• US 20120234070A1
• Filed: 03/14/2011
• Published: 09/20/2012
• Est. Priority Date: 03/14/2011
• Status: Active Grant

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Golovashchenko, Sergey Fedorovich
• Granted Patent: US 8,756,970 B2
• Time in Patent Office: Days
• US Class Current: 72/348
• 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
• CPC Class Codes: B21D 24/04 Blank holders; Mounting means therefor

Abstract

A method of forming a blank into a part shape is provided in which the blank is drawn into one or more channels sequentially to form at least one pocket of material that is available to be drawn into the die cavity. Each pocket is formed by applying liquid pressure or mechanical pressure to form the blank into the channels. The channels may be filled with a liquid to reduce friction. Alternatively, portions of the blank may be drawn into a channel to form a first stage preform that includes a pocket. The pocket of the first stage preform is then drawn into the die cavity in a first partial drawing stage. The steps of drawing material into the channel and then into the die cavity may be repeated one or more times until the part is fully drawn into the desired shape.

Claims

1. A method of forming a part comprising:

clamping a blank between a blank holder and a die;

applying pressure at a selected area against a first side of the blank;

forming the blank into a pocket disposed on the second side of the blank on the opposite the selected area;

relieving the pressure on the selected area; and

drawing the blank into the die and out of the pocket.

2. The method of claim 1 wherein the step of applying pressure at the selected area further comprises providing a liquid under pressure through a channel formed in a blank holder.

3. The method of claim 1 wherein the step of applying pressure at the selected area further comprises engaging the blank with a channel punch that is advanced through the blank holder.

4. The method of claim 1 wherein the selected area is a first selected area and the pocket is a first pocket, wherein the method further comprises:

relieving the pressure on the first selected area;

applying pressure at a second selected area that is inboard from the first selected area against a first side of the blank;

forming the blank into a second pocket that is inboard from the first pocket disposed on the second side of the blank that is on the opposite side of the blank from the selected area; and

relieving the pressure on the second selected area before the drawing step.

5. The method of claim 4 wherein the step of applying pressure at the second selected area further comprises providing a liquid under pressure through a channel formed in a blank holder.

6. The method of claim 4 wherein the step of applying pressure at the second selected area further comprises engaging the blank with a channel punch that is advanced through the blank holder.

7. The method of claim 4 wherein the die defines a die cavity and the first and second pockets are formed in a lower die that is outboard from the die cavity.

8. The method of claim 7 wherein the first and second pockets extend about the periphery of the die cavity.

9. The method of claim 4 wherein the first pocket is filled with a liquid before the step of forming the blank into the first pocket and the second pocket is filled with a liquid before the step of forming the blank into the second pocket.

10. The method of claim 1 wherein the die defines a die cavity and the pocket is formed in a lower die that is outboard from the die cavity.

11. The method of claim 10 wherein the pocket extends about the periphery of the die cavity.

12. The method of claim 1 wherein the pocket is filled with a liquid before the step of forming the blank into the pocket.

13. A method of drawing a blank to form a drawn panel comprising:

forming a first peripheral pocket in the blank in a portion of the blank that is clamped by a blank holder on a lower die;

forming a second peripheral pocket in the blank in a portion of the blank that is inboard of the first pocket and is clamped by a blank holder on a lower die; and

drawing the blank into the lower die to form the drawn panel.

14. The method of claim 13 wherein the steps of forming the first and second peripheral pockets are performed sequentially by porting a liquid under pressure to a top side of the blank to cause the blank to be formed initially into a first pocket forming area and then into a second pocket forming area on the lower die.

15. The method of claim 14 wherein the first and second pockets are formed sequentially with the first pocket being formed first and the second pocket being formed after relieving the pressure in the first pocket.

16. The method of claim 15 wherein the step of drawing the blank into the lower die is performed after relieving the pressure in the second pocket.

17. The method of claim 13 wherein the steps of forming the first and second peripheral pockets is performed by drawing the blank into the first pocket with a first channel punch that engages a top side of the blank to cause the blank to be formed into a first pocket forming area on the lower die and by subsequently drawing the blank into the second pocket forming area on the lower die.

18. The method of claim 17 wherein the first and second pockets are formed sequentially with the first pocket being formed first and the second pocket being formed after the first channel punch is retracted from engagement with the blank.

19. A method of drawing a blank to form a drawn panel comprising:

forming a first peripheral pocket in the blank in a portion of the blank that is clamped by a blank holder on a lower die, wherein the first peripheral pocket is formed into a channel provided in one of the blank holder and the lower die;

drawing the blank partially into the lower die from the first peripheral pocket to partially form the drawn panel;

forming a second peripheral pocket in the blank in a portion of the blank that is clamped by a blank holder on a lower die, wherein the second peripheral pocket is formed into the channel provided in one of the blank holder and the lower die; and

drawing the blank into the lower die from the second peripheral pocket.

20. The method of claim 19 further comprising;

forming a third peripheral pocket in the blank in a portion of the blank that is clamped by a blank holder on a lower die, wherein the third peripheral pocket is formed into the channel provided in one of the blank holder and the lower die; and

drawing the blank into the lower die from the third peripheral pocket to form the drawn panel.