Patent · US Expired

Method of controlling speed reduction ratio for a continuously variable speed transmission

US4956972A · kind A · utility

16Cited by
8References
4Claims
0Family size

Assignee

Inventors

Key dates

Filing dateDec 16, 1988
Grant dateSep 18, 1990
Priority date
Expiry dateDec 16, 2008

Classification

  • Technology area (CPC F)Mechanical Engineering; Lighting; Heating
  • CPC primaryF16H61/462
  • WIPO fieldMechanical elements
  • WIPO sectorMechanical engineering

Abstract

The speed reduction ratio of a continuously variable speed transmission for transmitting engine power with continuously variable speed to drive road wheels is controlled by detecting a parameter representing a driver's intention of acceleration or deceleration, establishing a reference engine speed corresponding to the detected parameter, and controlling the speed reduction ratio so as to equalize an actual engine speed with the reference engine speed, at a predetermined time interval. When the actual engine speed is lower than the reference engine speed, a controlling ouput value for the speed reduction ratio for bringing the actual engine speed into agreement with the reference engine speed is established based on the difference between the actual engine speed and the reference engine speed, and a predicted engine speed after elapse of the predetermined time interval is calculated based on the rate of =change of the actual engine speed. When the predicted engine speed is higher than the reference engine speed, the controlling output value is corrected to lower the predicted engine speed below the reference engine speed after elapse of the predetermined time interval.

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