Patent ID: 9327711
Filing Date: 2016-05-03
CPC Classification: B60K,B60W,B60Y,F02D,F16H,Y02T,Y10S

Claim Text:
1. A control device for a hybrid vehicle automatic transmission for use in a hybrid vehicle having an automatic transmission including a friction engagement element provided in a power transfer path between an internal combustion engine and drive wheels and actuated by oil from a mechanical oil pump driven by the internal combustion engine, the hybrid vehicle being capable of EV travel in which drive wheels are driven by only a rotary electric machine with the internal combustion engine stopped, the control device comprising: electric oil pump controller configured to drive an electric oil pump that supplies oil to the friction engagement element; neutral controller configured to disengage the friction engagement element to bring the automatic transmission into a neutral state during the EV travel; drag determination device configured to determine whether conditions under which drag of the friction engagement element occurs are met because of a shortage in amount of oil to be supplied to a cancellation oil chamber of the friction engagement element by the electric oil pump during the EV travel started from a state in which the hybrid vehicle is stationary; drag elimination controller configured to provide a command to start the internal combustion engine to rotationally drive the mechanical oil pump in the case where the drag determination device determines that the conditions under which drag occurs are met; and vehicle speed sensing means for sensing a vehicle speed of the hybrid vehicle, wherein the conditions under which drag occurs are set to be met more easily as the vehicle speed is higher.