# US 7,788,805 B2 · Method for manufacturing rocker arm

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- Number: US 7,788,805 B2
- Document ID: US7788805B2
- Status: Granted
- Kind: B2
- Application number: 11/990,783
- Filed: 2006-08-01
- Published: 2009-06-11
- Granted: 2010-09-07
- Earliest claimed: 2005-08-22
- Assignees: Nakanishi Metal Works Co., Ltd.; Otics Corporation
- Inventors: Michiyuki Kamiji
- Web page: https://patentgrep.com/patent/US7788805B2

## CPC

- B21K 1/205: {rocker arms}
- B21D 53/88: other parts for vehicles, e.g. cowlings, mudguards
- B21J 5/06: for performing particular operations
- B21K 23/00: Making other articles
- B23P 15/00: Making specific metal objects by operations not covered by a single other subclass or a group in this subclass
- F01L 1/18: Rocking arms or levers
- F01L 1/185: {Overhead end-pivot rocking arms}
- F01L 2303/01: Tools for producing, mounting or adjusting, e.g. some part of the distribution
- F01L 2305/00: Valve arrangements comprising rollers
- Y10T 29/49295: Push rod or rocker arm making
- Y10T 29/49995: Shaping one-piece blank by removing material
- 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)
- B21D: WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL (working or processing of wire B21F)
- 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)
- B23P: METAL-WORKING NOT OTHERWISE PROVIDED FOR; COMBINED OPERATIONS; UNIVERSAL MACHINE TOOLS (arrangements for copying or controlling B23Q)
- F01L: CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES
- Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION

## Abstract

The present invention provides a rocker arm manufacturing method capable of improving the durability and excellent in productivity. In the method according to the present invention, an intermediate product 13 having both side walls 20 extended in a predetermined direction and arranged in parallel with each other and one end side connection wall 30 connecting lower ends of a longitudinal one end of both the side walls is obtained. Next, both side walls 20 formed at the one end of the intermediate product 13 are inwardly bent. Thereafter, ironing dies 60 are pressed down against outer surfaces of both the inclined side walls 20 from an upper side to a lower side to execute ironing of outer surface portions of both the side walls 20 to downwardly plastically fluidize the constituent material of both the side walls 20 to thereby form valve stem guide walls 35 at both sides of the one end side connection wall 30 in a downwardly protruded manner.

## Claims

### Claim 1

A method for manufacturing a rocker arm, the method comprising:
a step of obtaining an intermediate product having two side walls with both side walls extended in a predetermined direction and arranged in parallel with each other and having a one side connection wall connecting lower ends of both the side walls at a longitudinal one end side of the intermediate product;
a side wall bending step of inwardly bending both the side walls formed at the one end of the intermediate product; and
an ironing step of forming valve stem guide walls at both sides of the one end side connection wall in a downwardly protruded manner by pressing down ironing dies against outer surfaces of both the inclined side walls from an upper side to a lower side to execute ironing of outer surface portions of both the side walls to plastically fluidize constituent material of both the side walls.

### Claim 2 (depends on 1)

The method for manufacturing a rocker arm as recited in claim 1, wherein, at the ironing step, the intermediate product is secured by clamping the one end side connection wall by and between an upper die and a lower die, and the ironing dies are pressed down in a state in which gaps are formed between the upper die and inner surfaces of basal end portions of the side walls.

### Claim 3 (depends on 1)

The method for manufacturing a rocker arm as recited in claim 1, wherein non-ironing processed portion is provided at longitudinal end portions of both the side walls.

### Claim 4 (depends on 2)

The method for manufacturing a rocker arm as recited in claim 2, wherein non-ironing processed portion is provided at longitudinal end portions of both the side walls.