Patent · US Expired

Adaptive direct pressure shift control for a motor vehicle transmission

US4707789A · kind A · utility

85Cited by
6References
14Claims
0Family size

Assignee

Inventors

Key dates

Filing dateNov 29, 1985
Grant dateNov 17, 1987
Priority date
Expiry dateNov 29, 2005

Classification

  • Technology area (CPC F)Mechanical Engineering; Lighting; Heating
  • CPC primaryF16H2061/0255
  • WIPO fieldMechanical elements
  • WIPO sectorMechanical engineering

Abstract

An adaptive shift control system for regulating the operation of a fluid operated torque establishing device associated with a specified speed ratio in a motor vehicle automatic transmission. Shifting from a currently engaged speed ratio to the specified speed ratio includes a preparation phase during which fluid is supplied to the torque establishing device for a predetermined time to fill the same in preparation for torque transmission, and a completion phase during which further fluid is supplied to the device to initiate and progressively increase the transmission of torque therethrough. The change in transmission input speed due to the initiation of torque transmission through the torque establishing device is identified and used to detect the occurrence of overfill or underfill conditions. The predetermined time is adjusted based on such detection so as to adaptively compensate for sources of error which degrade the shift quality by causing overfill or underfill conditions.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.