Shift synchronization using decaying torque

US6126570A · kind A · utility

Assignee

• ZF Meritor, LLC · US

Inventors

• Andreas Böhm · Wennigsen (Deister), DE
• Gerhard Bockmann · Laatzen, DE
• James DeVore · Laurinburg, US
• Jon M. Huber · Laurinburg, US
• Robert Sayman · Eriskirch, DE

Key dates

• Filing date: Jul 6, 1999
• Grant date: Oct 3, 2000
• Expiry date: Jul 6, 2019

Classification

• Technology area (CPC F): Mechanical Engineering; Lighting; Heating
• CPC primary: F16H2306/46
• WIPO field: Transport
• WIPO sector: Mechanical engineering

Abstract

A method of engaging and disengaging transmission gears in a vehicle is provided. A controller processes an initial torque representing an engine torque and an estimated zero torque representing an estimate of a transmission output shaft torque. The controller also sets a high and low band torque about the estimated zero torque. Once the above torques have been determined, the controller compares the initial torque to the high band torque. If the initial torque is below the high band torque, the controller increases the engine torque to the high band torque. If the initial torque is greater than the high band torque, then no preliminary adjustments to the engine torque need be made. At least one shift valve is energized when the engine torque is equal to or greater than the high band torque. The engine torque is decayed by the controller to the low band torque to facilitate engaging and disengaging transmission gears.