Patent ID: 7543693
Filing Date: 2009-06-09
Classification: F16H,Y10T

Abstract:
1. A neutral control apparatus for an automatic transmission of a vehicle, comprising: an engagement load adjustment device that adjusts an engagement load of a friction engagement device of the automatic transmission, to which drive power is transmitted from a drive power source of the vehicle via a torque converter; and a controller that performs, when the vehicle is at a standstill, a neutral control by reducing the engagement load of the friction engagement device, the controller being adapted to: estimate a temperature of the friction engagement device; calculate a target speed ratio of the torque converter according to the estimated temperature of the friction engagement device, the speed ratio being a ratio of an output speed to an input speed of the torque converter, the target speed ratio being calculated to be larger when the estimated temperature of the friction engagement device is higher; and control the engagement load adjustment device so as to achieve the target speed ratio during the neutral control.