LEAF SPRING DEVICE HAVING EYE, LEAF SPRING DEVICE MANUFACTURING METHOD, AND SHOT PEENING APPARATUS

摘要

A leaf spring device (10) is provided with a leaf spring (11), which has an eye (12) at each end thereof, and a bushing (20) press-fitted into the eye (12) . An inner surface (30) of the eye (12) is shaved by means of a reamer or the like and is shot-peened. A compressive residual stress distribution on the inner eye surface (30) formed by the shot peening is such that the absolute value of a compressive residual stress (τ1 in a first region (S1), including a winding start portion (31) of the eye (12), and the absolute value of a compressive residual stress (τ2) in a second region (S2), including a winding intermediate point (32) of the eye (12), are greater than the absolute values of compressive residual stresses (τ3) in other regions (S3) of the inner eye surface (30).