Patent ID: 8249783

Claim:
A vehicle automatic transmission comprising: an input shaft to which a driving force is to be input from a driving source; a countershaft; an output shaft configured to output the driving force to driving wheels; a plurality of gears meshed with one another and provided on the input shaft, the countershaft, and the output shaft; a plurality of hydraulic clutches each configured to couple any of the gears to the input shaft, the countershaft, or the output shaft that supports the gears rotatably so as to establish a predetermined shift stage; an engagement unit configured to couple a reverse gear to the input shaft or the countershaft to establish a reverse shift stage, the reverse gear being constantly coupled to the output shaft via any of the gears; a shift-position detection unit configured to detect a shift position; a vehicle-speed detection unit configured to detect a vehicle speed; and a control unit configured to detect, based on an output of the shift-position detection unit, a first time in which the shift position changes from a D-position to an R-position and a second time in which the shift position changes from the D-position to a P-position, and configured to delay a timing when the engagement unit operates after the shift position changes to the R-position under a condition that the vehicle speed detected by the vehicle-speed detection unit is zero and the first time is shorter than or equal to a first threshold value or the second time is shorter than or equal to a second threshold value.