System and method for controlling a continuously variable transmission when transitioning operation from a hydrostatic mode to a hydro-mechanical mode

摘要

In one aspect, a method for controlling a continuously variable transmission when transitioning the transmission from operation within a hydrostatic mode to operation within a hydro-mechanical mode may generally include initially operating the transmission in the hydrostatic mode, receiving a mode switch signal associated with transitioning the operation of the transmission to the hydro-mechanical mode and initiating a clutch swap between a secondary range clutch and a directional clutch of the transmission. In addition, the method may include adjusting a swash plate angle of the transmission as the directional clutch is slipped in order to transition the operation of the transmission to a point along a hydro-mechanical operating curve and fully engaging the directional clutch to allow operation of the transmission along the hydro-mechanical operating curve.

主权项

1. A method for controlling a continuously variable transmission of a work vehicle when transitioning operation from a hydrostatic mode to hydro-mechanical mode, the continuously variable transmission configured to provide a hydrostatic drive, the method comprising:
operating the continuously variable transmission in the hydrostatic mode such that a first range clutch and a secondary range clutch of the continuously variable transmission are engaged and a directional clutch of the continuously variable transmission is disengaged, the first range clutch being associated with operating the continuously variable transmission within a first speed range; monitoring a drivetrain torque of the work vehicle; receiving, with a computing device, a mode switch signal associated with transitioning the operation of the continuously variable transmission from the hydrostatic mode to the hydro-mechanical mode while a ground speed of the work vehicle is below a maximum ground speed associated with the first speed range, wherein the mode switch signal corresponds to a signal that is generated when the drivetrain torque exceeds a predetermined torque threshold; initiating a clutch swap between the secondary range clutch and the directional clutch such that the secondary range clutch is disengaged and the directional clutch begins to slip; adjusting a swash plate angle of the hydrostatic drive as the directional clutch is slipped in order to transition the operation of the continuously variable transmission to an operating point defined along a hydro-mechanical operating curve associated with the first speed range for the hydro-mechanical mode; and fully engaging the directional clutch to allow operation of the continuously variable transmission along the hydro-mechanical operating curve.