Patent ID: 7043836
Filing Date: 2006-05-16
Classification: B21K,F01L,Y10T

Abstract:
1. A method of manufacturing a rocker arm for opening and closing a valve, the method comprising: providing a metallic sheet; bending the metallic sheet to form a pair of predetermined side wall regions and a predetermined connecting wall region for connecting the pair of predetermined side wall regions; first pressing a portion of outer sides of the pair of predetermined side wall regions in a connecting direction in which the predetermined connecting wall region extends, respectively, to plastically flow so that a height of the pair of predetermined side wall regions is gradually increased; second pressing the predetermined connecting wall region so as to be recessed in a height direction perpendicular to the connecting direction; and alternately repeating the first pressing and the second pressing a plurality of times, whereby portions of the pair of predetermined side wall regions are made to be a pair of valve guide walls of a valve engaging portion which extends in the height direction, in which the predetermined connecting wall region is made to be a connecting wall of the valve engaging portion, which connects the pair of valve guide walls with each other at an intermediate portion of the pair of valve guide walls in the height direction, wherein a metal flow continues between the pair of valve guide walls, including distal ends, of the pair of valve guide walls and the connecting wall.