| 摘要 |
PROBLEM TO BE SOLVED: To provide a power steering device capable of securing the sufficient strength of a lock nut.SOLUTION: A blank 40a made of a hollow ferrous metal material is formed by forging, and the inner peripheral surface of the blank 40a is accordingly used directly as the inner peripheral surface of a lock nut 30. Thus, conventionally carried out piecing and machining for eliminating burrs generated by the piercing can be omitted. Thus, the omission of the conventional piercing is enabled, there is no need to secure the allowance (expanded diameter part) of a punch during the piercing, and a proper thickness can be secured for the lock nut. Thus, sufficient strength can be secured.SELECTED DRAWING: Figure 5 |
