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 (?1) IN A FIRST REGION (S1), INCLUDING A WINDING START PORTION (31) OF THE EYE (12), AND THE ABSOLUTE VALUE OF A COMPRESSIVE RESIDUAL STRESS (?2) 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 (?3) IN OTHER REGIONS (S3) OF THE INNER EYE SURFACE (30).