Patent ID: 10047853

Abstract:
Oil pressure controller for an automatic transmission produces a pre-charge shelf pressure supplied to a starter clutch by rapidly decreasing a command hydraulic pressure to the starter clutch after temporarily rapidly increasing the command hydraulic pressure, also produces a capacity adjustment pressure (Pb1 or Pb2) of the starter clutch by gradually increasing the hydraulic pressure from a decrease point of the pre-charge shelf pressure (Pa), when a selecting operation is made from N-range to D-range. By changing capacity adjustment pressure (Pb1 or Pb2) according to brake-operating/nonoperating state, capacity adjustment pressure (Pb1) in the brake-nonoperating state is set to be higher than capacity adjustment pressure (Pb2) in the brake-operating state by an offset hydraulic pressure amount. With this, when the selecting operation is made from N-range to D-range, in the brake-operating state, selection shock of the starter clutch can be reduced. In the brake-nonoperating state, good vehicle startability can be achieved.