Patent ID: 8660762
Filing Date: 2014-02-25
Classification: B60W,F16H

Abstract:
1. An automatic transmission that has a heat exchanger for cooling a working oil and receives a supply of the working oil from the heat exchanger, comprising: a working oil temperature sensor that is configured to obtain a temperature of the working oil in the automatic transmission; a temperature increase promotion processing starting unit which is configured to start a temperature increase promotion processing that promotes an increase in the temperature of the working oil when: an initial value of the temperature of the working oil obtained by the working oil temperature sensor is in a low temperature region, in which a viscosity of the working oil rises such that activation of a frictional engagement element in the automatic transmission is delayed, and the initial value of the temperature of the working oil is in an extremely low temperature region that is a lower temperature region than the low temperature region, in which the viscosity of the working oil rises further such that the working oil is not supplied sufficiently from the heat exchanger to the automatic transmission; and a temperature increase promotion processing terminating unit which is configured to: determine whether the temperature increase promotion processing is complete on a basis of a current temperature of the working oil obtained by the working oil temperature sensor in a case where the temperature increase promotion processing is started while the initial value of the temperature of the working oil is in the low temperature region, determine whether the temperature increase promotion processing is complete on a basis of a duration of the temperature increase promotion processing in a case where the temperature increase promotion processing is started while the initial value of the temperature of the working oil is in the extremely low temperature region, and terminate the temperature increase promotion processing when the temperature increase promotion processing is determined to he complete.