# US 2009/0260410 A1 · Apparatus and Method for Manufacturing Sprocket Segment

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- Number: US 2009/0260410 A1
- Document ID: US20090260410A1
- Status: Published application
- Kind: A1
- Application number: 12/493,099
- Filed: 2009-06-26
- Published: 2009-10-22
- Earliest claimed: 2007-01-05
- Assignees: Daechang Forging Co., Ltd.
- Inventors: Bum Je Cho; Young Jin Jegal
- Web page: https://patentgrep.com/patent/US20090260410A1

## CPC

- B21K 1/30: with gear-teeth
- B21J 5/02: Die forging; Trimming by making use of special dies {; Punching during forging}
- B21K 23/02: members of endless tracks, e.g. track guides, shoes (making from sheet-metal B21D)
- B21K: MAKING FORGED OR PRESSED METAL PRODUCTS, e.g. HORSE-SHOES, RIVETS, BOLTS OR WHEELS (making particular articles by working sheet metal without essentially removing material B21D; processing wire B21F; making pins, needles or nails B21G; making particular articles by rolling B21H; forging machines, pressing machines, hammering machines, in general B21J; making chains B21L; plating B23K)
- B21J: FORGING; HAMMERING; PRESSING METAL; RIVETING; FORGE FURNACES (rolling of metal B21B; making particular products by forging or pressing B21K; cladding or plating B23K; finishing surfaces by hammering B23P9/04; compacting surfaces by blasting with particulate material B24C1/10; general features of presses, presses for consolidating scrap B30B; furnaces in general F27)

## Abstract

Disclosed therein are an apparatus and method for manufacturing a sprocket segment, which can manufacture the sprocket segment through a simplified process including hot precision forging, through hardening and painting, thereby reducing manufacturing period and cost and securing competitive power. The sprocket segment manufacturing method includes: a primary hot forging process of putting a heated billet in a booster die (10) mounted on a forging press to perform a distribution of volume; a secondary hot forging process of putting the hot forged material (M) in a blocker die (11) to form a rib face (4); a tertiary hot forging process of putting the secondarily hot forged material (M) in a finisher die (12) to keep right angles and planes of a toothed face (6) and the rib face (4); and a process of putting the tertiarily hot forged material (M) in a product guide die (22) of a trimming-piercing-coining die (13) to eliminate a flash and form bolt holes (7) simultaneously.

## Claims

### Claim 1

An apparatus for manufacturing a sprocket segment, which is installed on a press to manufacture the sprocket segment (1) by means of a hot forging process, comprising:
a bending type booster die (10) having an upper die (14) and a lower die (15) for primarily hot-forging a heated billet in a booster type to distribute its volume;
a blocker die (11) having an upper die (16) and a lower die (17) for secondarily hot-forging the material (M) hot-forged in the booster die (10) to form a rib face (4);
a finisher die (12) having an upper die (18) and a lower die (19) for tertiarily hot-forging the material (M) primarily and secondarily hot-forged in the blocker die (11) to keep right angles and planes of a toothed face (6) and the rib face (4);
knock-out pins (21) mounted on the upper dies (16; 18) and the lower dies (17; 19) of the blocker die (11) and the finisher die (12) and elastically mounted on springs (20) for extracting a product;
a trimming-piercing-coining die (13) for simultaneously trimming, piercing and coining the material (M) hot-forged three times;
a product guide die (22) fixed on the upper portion of a lower trimming holder (28) of the trimming-piercing-coining die (13), on which the material (M) is seated;
a flash cutting die (23) mounted on an upper trimming holder (30) located above the product guide die (22);
a piercing punch (25) vertically mounted on a cushion stripper (24); and
a flash eliminating die (27) mounted in both side directions of the product guide die (22) for eliminating a flash cut by an operation of an air cylinder (26).

### Claim 2

A method for manufacturing a sprocket segment (1) by performing a hot forging and a precision trimming on a forging press, the method comprising:
a primary hot forging process of putting a heated billet between an upper die (14) and a lower die (15) of a bending type booster die (10) to distribute a volume;
a secondary hot forging process of putting the primarily hot forged material (M) between an upper die (16) and a lower die (17) of a blocker die (11) to form a rib face (4);
a third hot forging process of putting the secondarily hot forged material (M) between an upper die (18) and a lower die (19) of a finisher die (12) to keep a right angle and a plane of a toothed face (6) and the rib face (4); and
a process of putting the tertiarily hot forged material (M) on a product guide die (22) of a trimming-piercing-coining die (13) and eliminating a flash and piercing bolt holes (7) by a flash cutting die (23) and a piercing punch (25) vertically mounted on a cushion stripper (24).