| 摘要 |
PROBLEM TO BE SOLVED: To provide a sintered metallic sprocket excellent in wear resistance and having an improved tooth from precision by improving a tooth surface density close to a true density. SOLUTION: A sprocket is formed by sintering an iron base powder metal. The sprocket as an intermediate product has a form rolling margin respectively for a tooth bottom land, tooth face, tooth top land. A form rolling tool 22 in recessed shape has the cross sectional shape corresponding to a tooth from of the sprocket, when the form rolling tool 22 in recessed shape is brought into contact with the teeth without clearance, an excess stock of respective teeth are drawn toward the inside as a whole by the form rolling face of the form rolling tool 22 in recessed shape. Further, the tooth form created by the form rolling face of the form rolling tool 22 in recessed shape is transferred to the tooth bottom land, tooth face, tooth top land of the tooth of the sprocket S.
|
