Patent ID: 6544142
Filing Date: 2003-04-08
Classification: B60W,F16H,Y10T

Abstract:
An automatic transmission system for a vehicle having an input shaft, an output shaft, a plurality of drive gears mounted on said input shaft, a plurality of driven gears mounted on said output shaft and meshing with said drive gears, a torque converter disposed between a crankshaft of an engine and said input shaft, synchromesh mechanisms for synchronously engaging said drive gears with said driven gears and a shift controller for automatically actuating said synchromesh mechanisms so as to obtain a required gear ratio, comprising:a lock-up clutch incorporated in said torque converter between said crankshaft and an output element of said torque converter for connecting said crankshaft with said input shaft; an electronically controlled throttle valve for automatically operating to reduce a rotation speed of said crankshaft when the gear is shifted so as to smoothly synchronize said drive gears with said driven gears; a bypass clutch for transmitting torque from said input shaft to said output shaft when the gear is shifted, while said electronically controlled throttle valve operates to reduce a rotation speed of said engine; an input clutch disposed between said output element of said torque converter and said input shaft for selectively controlling a torque transmission from said output element of said torque converter to said input shaft when the gear is shifted; and a brake mechanism for additionally reducing a rotational speed of said crankshaft while said electronically controlled throttle valve operates to reduce a rotational speed of said crankshaft so as to smoothly and swiftly engage said drive gears with said driven gears.