| 摘要 |
PROBLEM TO BE SOLVED: To prevent a lock up clutch from extending a time till fastening is started really by lock up judgement, in the case where oil pressure in an oil passage is reduced when a throttle opening degree is narrow. SOLUTION: When lock up is judged, increase of the duty ratio of a power pulse signal supplied to a lock up solenoid 24 is started from an initial value at a constant increasing rate. Power for pressing a spool 21 in a left direction by reducing control pressure PC of an oil passage R5 in association with increase of a duty ratio DH is lower than a pressure by oil pressure PT supplied to the left side space of a plug 22 and a pilot pressure PP through an oil pressure R6, movement of the spool 21 is started, and a lock up clutch 13 becomes a half-clutch condition. When a throttle opening degree is narrow, an initial value which is larger than it is selected, and fastening of the lock up clutch 13 is started at a same degree time as a larger case. |
