Forging method

Patent metadata

Field	Value
Publication number	US-9555505-B2
Application number	US-201214002376-A
Country	US
Kind code	B2
Filing date	Feb 28, 2012
Priority date	Mar 3, 2011
Publication date	Jan 31, 2017
Grant date	Jan 31, 2017

Abstract

The present invention is directed to a forging method for forming a heat sink 9 including a base board 91 and a plurality of pin fins 92 integrally formed on an upper surface of the base board 91 . A back pressure applying pin 75 of a forging die for forming pin fins 92 are slidably arranged in a fin-forming hole 52 . At the time of plastically deforming a forging blank W, a back pressure is applied by the back pressure applying pin to a metal material of the forging blank W flowed into the fin-forming hole 52 . A concave portion 76 is formed on the restraining tip end face of the back pressure applying pin 75 for restraining the metal material, and a joining convex portion 93 is integrally formed on a tip end of the pin fin 92 by the metal material filled in the concave portion 76.

First claim

The invention claimed is:

1. A forging method for forming a heat sink including a base board and a plurality of pin fins integrally formed on at least one surface of the base board by plastically deforming a forging blank by die forging processing, the method comprising:
arranging a back pressure applying pin in a fin-forming hole for forming the pin fin in a slidable manner, the fin-forming hole being formed in a forging die, wherein the back pressure applying in includes a concave portion on a restraining tip end face of the back pressure applying pin;
applying a back pressure to a metal material of the forging blank flowing into the fin-forming hole with the back pressure applying pin at a time of plastically deforming the forging blank;
restraining the metal material with the concave portion on the restraining tip end face of the back pressure applying pin; and
integrally forming a joining convex portion on a tip end of the pin fin by the metal material filled in the concave portion.

2. The forging method as recited in claim 1 , wherein the joining convex portion of the pin fin protrudes higher than a thin protruded portion formed at a tip end outer peripheral edge of the pin fin.

3. The forging method as recited in claim 2 , wherein the thin protruded portion is formed by burrs.

4. The forging method as recited in claim 1 , wherein a tip end of the joining convex portion of the pin fin is formed into a flat surface.

5. The forging method as recited in claim 1 , wherein the forging die includes a punch and a die, and wherein the fin-forming hole is provided in the punch.

6. The forging method as recited in claim 1 , wherein the forging die includes a punch and a die, and wherein the fin-forming hole is provided in the die.

7. A production method of a heat sink including a heat transfer plate, the method comprising:
a step of obtaining a heat sink by a forging method as recited in claim 1 ; and
a step of fixedly joining a heat transfer plate to tip ends of a plurality of pin fins without removing thin protruded portions formed at tip end outer peripheral edges of the plurality of pin fins of the heat sink.

8. A production method of a heat sink including a heat transfer plate, the method comprising:
a step of obtaining a heat sink by a forging method as recited in claim 1 ;
a correction step of adjusting protruding amounts of joining convex portions of a plurality of pin fins of the heat sink by pressing a corrective punch having a flat pressing surface against tip ends of the plurality of pin fins; and
a joining step of fixedly joining a heat transfer plate to the tip ends of the plurality of pin fins after performing the correction step.

9. A correction method of a heat sink, comprising:
a step of obtaining a heat sink by a forging method as recited in claim 1 ; and
a correction step of adjusting protruding amounts of joining convex portions of a plurality of pin fins of the heat sink by pressing a corrective punch having a flat pressing surface against tip ends of the plurality of pin fins.

10. A forging device for forming a heat sink including a base board and a plurality of pin fins integrally formed on at least one surface of the base board by plastically deforming a forging blank by die forging processing, the forging device comprising:
a forging die;
a back pressure applying pin arranged in a fin-forming hole of the forging die, wherein
a restraining tip end face of the back pressure applying in includes a concave portion that restrains a metal material of the forging blank so that a joining convex portion is integrally formed on a tip end of a pin fin by the metal material filled in the concave portion.

Assignees

• Kokubo Sadao
• Igarashi Kazuo
• Showa Denko Kk

Inventors

• Kokubo Sadao
• Igarashi Kazuo

Classifications

• H10W70/027

  Mechanical treatments, e.g. deforming, punching or cutting · CPC title

• H10W40/228

  the projecting parts being wire-shaped or pin-shaped · CPC title

• F28F3/02

  Elements or assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with recesses, with corrugations (F28F3/08 takes precedence) · CPC title

• B21C23/186 Primary

  by backward extrusion · CPC title

• B21K23/00

  Making other articles · CPC title