FASTENING PRESSURE CONTROL DEVICE FOR STARTING FRICTION ELEMENT AT TIME OF CONTROLLING IDLE STOP OF VEHICLE

摘要

[Task] A required draining capacity of an electrically-powered oil pump is reduced and a small sizing of the electrically-powered oil pump is achieved by devising how to issue a starting frictional element engagement pressure command value. [Means for solving the problem] An engine is restarted in response to an idle stop OFF command at t1 so that a gear shift control purpose hydraulic pressure is raised according to a working oil from an engine driven oil pump. An idle stop release time control of the engine is allowed according to a torque down unnecessary determination when a gear shift control purpose hydraulic pressure has reached to a set hydraulic pressure at t2. In a case where this allowance causes an engine torque Te to be raised from a torque down value toward a driving operation corresponding value by a predetermined gradient ”Te1, a command value of a starting frictional element engagement pressure P S is set to a control maximum value (a drain port opening angle of a clutch hydraulic pressure control valve for a clutch hydraulic pressure (an engagement pressure) command value is made small as compared with that in a case of an ordinary control (is made difficult to drain)) during the idle stop control including during the idle stop release time control. Thus, when starting frictional element engagement pressure P S is controlled upon receipt of this command value, the working oil from the electrically-powered oil pump is not needed to be drained. Consequently, the electrically-powered oil pump is not needed to discharge this draining working oil and the small-sizing can be achieved.