Patent · US Expired

Transmission clutch control system and method

US4527678A · kind A · utility

83Cited by
6References
12Claims
0Family size

Assignee

Inventors

Key dates

Filing dateDec 27, 1982
Grant dateJul 9, 1985
Priority date
Expiry dateDec 27, 2002

Classification

  • Technology area (CPC F)Mechanical Engineering; Lighting; Heating
  • CPC primaryF16H2306/52
  • WIPO fieldMechanical elements
  • WIPO sectorMechanical engineering

Abstract

A control system for transferring torque from a first, offgoing clutch to a second, oncoming clutch while a gear shift is being made includes speed sensors for determining the speeds of the engine shaft and the output shaft of the transmission, a gear selector position indicator, a throttle position indicator and a gear ratio sensor. Solenoid operated valves open and close a source of high pressure fluid to the clutches, whose engagement and disengagement holds the gear elements of the transmission by means of which the various speed ratios are produced. An electronic computer is supplied with the digital equivalent of the shaft speeds, the position of the gear selector and of the throttle. The engine speed-output shaft speed ratio is used as a feedback signal on the basis of which an error between its value and a commanded value is determined. An equation for determining the duty cycle is repetitively calculated and its value converted to a pulse width modulated electrical current that is applied to the solenoid windings. The equation corrects a previously calculated duty cycle with the feedback error value.

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