| 摘要 |
<p>PURPOSE:To carry out the smooth changeover of a clutch by maintaining the disconnecting side clutch oil pressure once at a pressure throttled by orifices, and then by draining the disconnecting side clutch oil pressure at the stage in which the connecting side clutch oil pressure has risen to that directly before the clutch is connected. CONSTITUTION:When a signal oil pressure is input through a clutch changeover valve 60 so as to disconnect a starting clutch 20 and to connect a direct- connecting clutch 6, a second drain changeover valve 80 first closes a drain port 85 to maintain once the state in which the oil pressure has decreased to that between orifices 92 and 93, and then it opens the drain port 85 for draining at the stage in which the oil pressure in the direct-connecting clutch 6 has risen to that directly before the clutch is connected. When the starting clutch 20 is connected and the direct-connecting clutch 6 is disconnected, in the same way by means of a first drain changeover valve 70, the oil pressure in the direct-connecting clutch 8 is once maintained at a prescribed oil pressure, and then is drained at the stage in which the oil pressure in the starting clutch 20 has risen to that directly before the clutch is connected. Thus, the blowing-up of an engine and the engaging shock can be prevented.</p> |
