Patent ID: 7740559
Filing Date: 2010-06-22
Classification: B60W,F16H,Y10T

Abstract:
1. A shift control device of a vehicular automatic transmission that establishes a plurality of gear steps of different speed change ratios by selectively engaging a plurality of friction engagement devices, and speed-changes rotation transferred from an engine to an input shaft, and outputs speed-changed rotation, in which if during a first shift in a power-off state, a second shift judgment for a second shift that is a power-on downshift is made, performs a second shift control of lowering an input shaft rotation speed to a synchronous rotation speed of a post-second shift gear step through an engagement control of the friction engagement devices in order to execute the second shift, the shift control device comprising: a shift-time throttle controller that, when the second shift is performed, performs a control of reducing a throttle valve opening degree of the engine to a predetermined degree of opening that causes the engine to output a torque that is able to bring the input shaft rotation speed of the input shaft to a rotation speed that is higher than the synchronous rotation speed of the post-second shift gear step; and a shift-time ignition timing controller that executes a retardation control of retarding an ignition timing of the engine when the input shaft rotation speed is dropped through the second shift control; wherein if the input shaft rotation speed at a time of the second shift judgment is greater than or equal to a retardation control start rotation speed that is determined on a basis of the synchronous rotation speed of the post-second shift gear step, the shift-time ignition timing controller starts the retardation control at a time point of the second shift judgment, and wherein if the input shaft rotation speed at the time of the second shift judgment is less than the retardation control staff rotation speed, the shift-time ignition timing controller starts the retardation control at a time point when the input shaft rotation speed becomes equal to or greater than the retardation control staff rotation speed.