LOCK-UP DEVICE FOR TORQUE CONVERTER

摘要

A lock-up device having multi-stage torsional characteristics is configured so as to reduce stress occurring in low-rigidity springs. This device is provided with: a retaining plate (29); a driven plate (30); pairs of outer peripheral torsion springs (31) which elastically connect both the plates (29, 30); a support plate (32); and inner peripheral torsion springs (33). The support plate (32) can rotate relative to both the retaining plate (29) and the driven plate (30) and causes each of the pairs of outer peripheral coil springs to act serially. The inner peripheral torsion springs (33) have a smaller length than the outer peripheral torsion springs (31). The rotation of the support plate (32) relative to the driven plate (30) is restricted when the stopper section (32d) of the support plate (32) comes into contact with the intermediate stopper section (30d) of the driven plate (30).