摘要 |
In friction engagement device having forward clutch 5 and clutch operation pack 6 controlling engagement/disengagement operation of the forward clutch 5, the clutch operation pack 6 has hydraulic piston 61, engagement pressure piston chamber 62, snap ring 64, diaphragm spring 65 and ball lock mechanism BL. The diaphragm spring 65 provides biasing engagement force to the forward clutch 5 at a clutch side of the hydraulic piston 61. The ball lock mechanism BL restrains movement, in a disengagement direction, of the hydraulic piston 61 at a position where the forward clutch 5 is in an engagement state by the biasing engagement force by exerting ON pressure on the engagement pressure piston chamber 62, and after restraining the movement of the hydraulic piston 61, maintains the restraint of the disengagement direction movement of the hydraulic piston 61 even when the ON pressure of the engagement pressure piston chamber 62 is drawn. |