Patent · US Expired

Automatic speed ratio control system for stepless transmission of automotive vehicles

US4229998A · kind A · utility

14Cited by
9References
3Claims
0Family size

Assignee

Inventors

Key dates

Filing dateJun 19, 1978
Grant dateOct 28, 1980
Priority date
Expiry dateJun 19, 1998

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY10S74/01
  • WIPO fieldTransport
  • WIPO sectorMechanical engineering

Abstract

An automatic speed ratio control system of integration servo mechanism type for a stepless transmission of an automotive vehicle. Speed ratio is controlled by a hydraulic pump motor of variable displacement type, which in turn is controlled by an actuator having a piston and a cylinder to which hydraulic oil is supplied. The system comprises a desired value signal generator which produces a desired value signal for an engine speed corresponding to a throttle opening or an output torque of an engine or which produces a desired value signal for an engine output torque corresponding to a throttle opening or an engine speed, a detector for producing a signal indicative of an engine speed or an output torque of an engine, a control signal generator for comparing the signal from the detector against the signal from the target desired value signal generator to produce a control signal in accordance with a deviation therebetween, and a controller responsive to the control signal to drive the actuator to change a speed ratio of the stepless transmission. The system is characterized by further comprising means for producing a signal indicative of the differential or pseudo-differential of a …

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