Patent · US Expired

Failsafe control system for automatic transmission

US5649880A · kind A · utility

18Cited by
2References
10Claims
0Family size

Assignee

Inventors

Key dates

Filing dateDec 22, 1995
Grant dateJul 22, 1997
Priority date
Expiry dateDec 22, 2015

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY10S477/906
  • WIPO fieldMechanical elements
  • WIPO sectorMechanical engineering

Abstract

A control system for control of a clutch interposed between a fluid transmission unit and a speed change unit in a vehicular automatic transmission. The control system includes a first R.P.M. detector for detecting clutch input side R.P.M. and a second R.P.M. detector for detecting clutch output side R.P.M. A stop state detector determines if the vehicle is at a standstill and a starting operation detector detects a starting operation by the driver. The hydraulic control unit includes a hydraulic servo for applying/releasing the input clutch, a control signal oil pressure generating solenoid valve for generating a control signal oil pressure, a control valve for regulating a forward running range pressure according to the control signal oil pressure to generate a control oil pressure; a change signal oil pressure generating solenoid valve for generating a change signal oil pressure and a change-over valve switchable by the change signal oil pressure, between a first position in which it feeds the forward running range pressure to the hydraulic servo, and a second position in which it feeds the control oil pressure to the hydraulic servo. A failure is decided if the clutch input/out…

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