TWO-SPEED SWITCH CONTROL DEVICE FOR FINAL REDUCTION GEAR IN ACCUMULATOR STATIC HYDRAULIC TRANSMISSION SYSTEM OF VEHICLE

摘要

PURPOSE:To perform electronic control of a two-speed switch control device for a final reduction gear in a accumulator static hydraulic transmission system of a vehicle. CONSTITUTION:By referring to the shift map of an empty car mode or a loading car mode, shifting to either high or low according to Vf and thetaA is decided at S5 or S6. The number Np of revolutions of a hydraulic pump motor on the secondary side is calculated and an inclined shaft angle thetap being a target to suppress follow-up rotation torque Td of a hydraulic pump to a proper value or less is calculated at S7. An inclined shaft angle control signal thetap is outputted at S8 to control to thetap. A drive signal MS (a switch signal for high and low) for a switch motor is outputted at S9. It is decided at S10 whether an actual inclined shaft angle thetap1 is equal to thetap and it is decided based on a motor drive voltage at S11 whether the switch motor completes operation. Upon completion of operation of the switch motor, a signal for completion of high and low switch is outputted at S12 and an output for a hydraulic pump motor on the secondary side is started at S13.