| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for manufacturing rocker arms capable of improving productivity. SOLUTION: This invented manufacturing method includes a first process providing a first intermediate product 1 including both side walls 20 and a connecting wall 30 connecting one end sides thereof and provided with a padding part 25 projecting upward on an outer side part at an upper end edge of both side walls 20, a second process providing a second intermediate product 2 having a material filling part 26 formed at an outside of a lower end both side part at the both side walls by pressing down the padding part 25 of the first intermediate product 1 by a press-in die 60 and making the outside part of the both side walls 20 plastically flow downward, a third process providing a third intermediate product 3 having the material filling part 26 formed on a rough formed wall part 27 by cutting an inside of the material filling part 26 of the second intermediate product 2 from a lower side by a cutting die 70, and a fourth process providing a rocker arm 10 having the rough formed wall part 27 formed on the valve stem guide wall 35 by forming a connection wall 30 of the third intermediate product 3 by the finishing die 80. COPYRIGHT: (C)2009,JPO&INPIT
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