Patent ID: 7232394
Filing Date: 2007-06-19
Classification: F16H,Y10T

Abstract:
1. An automatic transmission of a motor vehicle comprising: an oil pressure source for supplying working oil with a certain oil pressure; multiple hydraulic control portions for changing gears upon receiving oil pressure from the oil pressure source; and a drive unit for selectively communicating the oil pressure source with one of the hydraulic control portions in accordance with a shift position of a shift lever to be operated by a vehicle driver, wherein the drive unit comprises; a hydraulic circuit changing device, which is mechanically operated by the shift lever and changes a hydraulic circuit, so that one of the hydraulic control portions is selectively communicated with the oil pressure source; a position detecting device for continuously detecting a position of one of moving members of the hydraulic circuit changing device, and for outputting a detection signal corresponding to the position of the moving member; a pressure regulating device provided between the hydraulic circuit changing device and the hydraulic control portions for regulating a control oil pressure to be applied to the hydraulic control portions; and an electronic control unit for calculating a rate of changes in the detection signals from the position detecting device and for controlling the pressure regulating device in accordance with the rate of the changes in the detection signals.