| 摘要 |
<p>PURPOSE:To obtain a tone wheel which can be manufactured inexpensively by simple machining and which is light in weight and has high rigidity by a method wherein a high-rigidity part having at least three bent parts and a bent sectional shape is provided between an inner peripheral cylindrical part of a magnetic metal plate formed in the shape of a round wheel and a flat plate part around the cylindrical part. CONSTITUTION:A cylindrical part 15a is provided in the inner peripheral edge part of a tone wheel 11b formed of a magnetic metal plate in the shape of a round wheel and a flat plate part 16a is formed around the cylindrical part. In the flat plate part 16a, a plurality of through holes 17a and 17b are provided at equal intervals as reduced thickness parts. Between the cylindrical part 15a and the flat plate part 16a, a high-rigidity part 20 having three bent parts 21, 23 and 25 and a bent sectional shape is present. A round-wheel-shaped connecting part 22 is formed between the bent parts 21 and 23, while an outside cylindrical part 24 is formed between the bent parts 23 and 25. Since the high- rigidity part 20 being surrounded by the bent parts 21, 23 and 25 and having a large section modulus is present in this way, the rigidity of the tone wheel can be ensured sufficiently.</p> |
