Methodology for controlling a hydraulic control system of a continuously variable transmission

摘要

A hydraulic control system for a CVT may include a pressure regulator subsystem, a ratio control subsystem, a torque converter control (TCC) subsystem, a clutch control subsystem, and is enabled for automatic engine start/stop (ESS) functionality. A system and method are provided for performing an engine auto-stop in a vehicle having a CVT transmission and using an accumulator to fill the pulleys and clutches of the CVT, at least in part, during engine restart.

主权项

1. A continuously variable transmission comprising:
a hydraulic control system; a pump driven by the engine for supplying a pressurized hydraulic fluid to the hydraulic control system; a first pulley pair with a first moveable pulley; a second pulley pair with a second moveable pulley; a first torque transmitting device; a second torque transmitting device; and a controller having a preprogrammed digital computer and memory for storing control logic, the control logic including a first control logic for commanding a first pulley target pressure to the first moveable pulley, a second control logic for commanding a second pulley target pressure to the second moveable pulley, a third control logic for commanding one of a first torque transmitting device fill target pressure to the first torque transmitting device or a second torque transmitting device fill target pressure to the second torque transmitting device, a fourth control logic for determining whether a first pulley actual pressure is equal to or greater than the first pulley target pressure, a fifth control logic for determining whether a second pulley actual pressure is equal to or greater than the second pulley target pressure, and a sixth control logic for commanding a first torque transmitting device engagement target pressure to the first torque transmitting device or a second torque transmitting device engagement target pressure to the second torque transmitting device if the first pulley actual pressure is equal to or greater than the first pulley target pressure or the second pulley actual pressure is equal to or greater than the second pulley target pressure.