Patent ID: 8262540
Filing Date: 2012-09-11
Classification: B60W,B60Y,F02D,Y10T

Abstract:
1. A shift control device for a work vehicle that comprises a stepped automatic transmission, the stepped automatic transmission being configured to transmit an engine output via a torque converter and including a plurality of hydraulic clutches, the shift control device comprising: a control device that controls an engine rotation rate at the work vehicle and controls the stepped automatic transmission; a forward/reverse switchover member that outputs a forward/reverse switchover command for the work vehicle; and an operation quantity detection device that detects an accelerator pedal operation quantity in the work vehicle, wherein: as the forward/reverse switchover command is output via the forward/reverse switchover member while the work vehicle is traveling, the control device executes forward/reverse switchover control for the stepped automatic transmission and also controls the engine rotation rate so as to decrease the engine rotation rate gradually at a decrease rate to a target lower limit value selected to ensure that a reverse rotation of a turbine runner at the torque converter in the work vehicle does not occur, with the decrease rate being determined based upon a relationship between a hydraulic pressure time chart for controlling the hydraulic clutches and a turbine runner rotation rate which decreases as the engine rotation rate decreases.