Patent ID: 7568991
Filing Date: 2009-08-04
Classification: F16H,Y10T

Abstract:
1. An automatic transmission of a motor vehicle having first, second and third speed stages, the transmission comprising: a first frictional element that is disengaged in the first speed stage, engaged in the second speed stage established by a first speed change and disengaged in the third speed stage established by a second speed change; a second frictional element that is engaged in the first speed stage, disengaged in the second speed stage and disengaged in the third speed stage; a third frictional element that is disengaged in the first speed stage, disengaged in the second speed stage and engaged in the third speed stage; and a control means that, upon judgment of need of a speed change from the first speed stage to the third speed stage, starts the second speed change while carrying out the first speed change, carries out comparison between a hydraulic pressure command value for the first frictional element at the first speed change and another hydraulic pressure command value for the first frictional element at the second speed change to select a smaller one, and practically applies the smaller value to the first frictional element.