Method and apparatus for progressively forging a hard disk drive base plate

• US 9,481,932 B2
• Filed: 04/26/2012
• Issued: 11/01/2016
• Est. Priority Date: 04/26/2012
• Status: Expired due to Fees

• Current Assignee: Cheung WOH Technologies Limited (Woh Seng Holdings Pte Ltd.)
• Original Assignee: Cheung WOH Technologies Limited (Woh Seng Holdings Pte Ltd.)
• Inventors: Law, Kung Ying
• Primary Examiner(s): Bryant, David
• Assistant Examiner(s): Averick, Lawrence
• Application Number:
  US13/457,304
• Publication Number:
  US 20130283877A1
• Time in Patent Office: 1,650 Days
• Field of Search: 724/04, 724/050.1, 723/52, 723/56, 723/61, 723/792, 295/57, 148/649, 148/653, 427/438
• US Class Current: 1/1
• CPC Class Codes: B21C 23/06 Making sheets
• CPC Class Codes: B21K 23/00 Making other articles
• CPC Class Codes: C23C 18/32 Coating with nickel, cobalt or mixtures thereof with phosphorus or boron C23C18/50 takes precedence
• CPC Class Codes: G11B 25/043 using rotating discs

Abstract

A method and apparatus for forming a hard disk drive base plate with a sequence of progressive forging operations is described. The method may include advancing an initial hard disk drive base plate cut from an extruded sheet through a plurality of stations of a transfer die assembly. The method may also include performing a sequence of forgings on the initial hard disk drive base plate to progressively form parts on a hard disk drive base plate.

Claims

1. A method for forging a hard disk drive base plate, comprising:

advancing an initial hard disk drive base plate cut from an extruded sheet through a plurality of stations of a transfer die assembly; and

performing a sequence of progressive forgings on the initial hard disk drive base plate to progressively form parts for a hard disk drive base plate comprising;

performing a first forging, in the sequence of progressive forgings, on the initial hard disk drive base plate to partially form the hard disk drive base plate by moving a material thickness in a middle of the initial hard disk drive base plate to sides and a motor hub portion of the initial hard disk drive base plate, wherein a material thickness of the sides and motor hub portion of the initial hard disk drive base plate is at least twice a material thickness of the middle of the initial hard disk drive base plate after the moving,

performing a second forging, on the partially formed hard disk drive base plate from the first forging, that partially forms one or more parts comprising at least a ramp pad surface on a front side of the partially formed hard disk drive base plate and at least one or more reinforcement ribs on a back side of the partially formed hard disk drive base plate, and

performing at least a third forging, after the second forging in the sequence of progressive forgings, that fully forms the one or more parts on the front and back sides of the partially formed hard disk drive base plate.

2. The method of claim 1, wherein performing the sequence of progressive forgings on the initial hard disk drive base plate further comprises:

forming a motor hub, a voice coil motor relief surface, an actuator pivot bearing post, a disk relief surface, an actuator relief surface, an actuator sitting surface, a motor sitting surface on a front side and on a back side of the hard disk drive base plate, one or more reinforcement ribs, and one or more mounting bosses on the back side of the hard disk drive base plate.

3. The method of claim 2, wherein performing the sequence of progressive forgings on the initial hard disk drive base plate further comprises:

forming a disk filter holder, a flex bracket surface, one or more side walls, a latch boss, a crash stop post, a voice coil motor (VCM) locating posts, a ramp pad surface, one or more top cover mounting bosses, one or more top outer mounting bosses on the front side and the back side of the hard disk drive base plate, one or more printed circuit board assembly (PCBA) mounting bosses, one or more flex bracket mounting bosses, a PCBA recess surface, and one or more motor hub flex soldering holes.

4. The method of claim 1, wherein performing the sequence of progressive forgings on the initial hard disk drive base plate further comprises:

forming a honeycomb cell feature of the back side of the hard disk drive base plate.

5. The method of claim 1, wherein performing the sequence of progressive forgings on the initial hard disk drive base plate further comprises:

annealing the hard disk drive base plate after one or more stages in the sequence of progressive forgings.

6. The method of claim 1, further comprising:

trimming excess and overflow material, if any, from the hard disk drive base plate;

piercing a motor hub hole, an oblong hole on an actuator relief surface, and a flex bracket rectangle into the hard disk drive base plate;

machining datums and a motor hub;

drilling holes on a front and a back of the hard disk drive base plate; and

forming thread in the drilled holes.

7. The method of claim 1, further comprising:

cleaning the hard disk drive base plate; and

applying a surface treatment to the cleaned hard disk drive base plate.

8. The method of claim 7, wherein the applied surface treatment is an Electroless Nickel plating.

9. The method of claim 1, wherein the sequence of progressive forgings are performed at room temperature.

10. The method of claim 1, wherein press plates of stations of the transfer die assembly that perform the forging operations are coated with titanium nitride.

11. The method of claim 1, wherein the hard disk drive base plate is formed from an aluminum alloy.

12. The method of claim 11, wherein the aluminum alloy is aluminum 6061.

13. The method of claim 1, further comprising:

performing the second forging after the first forging to partially form at least one or more back mounting bosses on the back side of the partially formed hard disk drive base plate.

14. The method of claim 1, wherein the sequence of progressive forgings form, either partially or fully, different subsets of parts on the hard disk drive base plate at specific forging stages to manage a movement of material over the sequence of progressive forgings caused by different forging operations that progressively form the different subsets of parts in the sequence of progressive forgings to obtain a fully formed hard disk drive base plate with a uniform thickness.

15. A system for forging a hard disk drive base plate, comprising:

a transfer die assembly to advance an initial hard disk drive base plate cut from an extruded sheet through multiple stations of the transfer die assembly;

a plurality of stations from the multiple stations to perform a sequence of progressive forgings on the initial hard disk drive base plate to progressively form parts on a hard disk drive base plate, the plurality of stations to;

perform a first forging, in the sequence of progressive forgings, on the initial hard disk drive base plate to partially form the hard disk drive base plate by moving a material thickness in a middle of the initial hard disk drive base plate to sides and a motor hub portion of the initial hard disk drive base plate, wherein a material thickness of the sides and motor hub portion of the initial hard disk drive base plate is at least twice a material thickness of the middle of the initial hard disk drive base plate after the moving,

perform a second forging, on the partially formed hard disk drive base plate from the first forging, that partially forms one or more parts comprising at least a ramp pad surface on a front side of the partially formed hard disk drive base plate and at least one or more reinforcement ribs on a back side of the partially formed hard disk drive base plate, and

perform at least a third forging, after the second forging in the sequence of progressive forgings, that fully forms the one or more parts on the front and back sides of the partially formed hard disk drive base plate.

16. The system of claim 15, wherein the sequence of progressive forgings performed on the initial hard disk drive base plate by plurality of stations form a motor hub, a voice coil motor relief surface, an actuator pivot bearing post, a disk relief surface, an actuator relief surface, an actuator sitting surface, a motor sitting surface on a front side and on a back side of the hard disk drive base plate, one or more reinforcement ribs, and one or more mounting bosses on the back side of the hard disk drive base plate.

17. The system of claim 16, wherein the sequence of progressive forgings performed on the initial hard disk drive base plate by plurality of stations form a disk filter holder, a flex bracket surface, one or more side walls, a latch boss, a crash stop post, a voice coil motor (VCM) locating posts, a ramp pad surface, one or more top cover mounting bosses, one or more top outer mounting bosses on the front side and the back side of the hard disk drive base plate, one or more printed circuit board assembly (PCBA) mounting bosses, one or more flex bracket mounting bosses, a PCBA recess surface, and one or more motor hub flex soldering holes.

18. The system of claim 15, wherein the hard disk drive base plate is annealed after one or more stages in the sequence of progressive forgings.

19. The system of claim 15, wherein press plates of stations of the transfer die assembly that perform the forging operations are coated with titanium nitride.

20. The system of claim 15, wherein the hard disk drive base plate is formed from an aluminum alloy.

21. The system of claim 20, wherein the aluminum alloy is aluminum 6061.