Patent · US Expired

Hydraulic pressure controller for automatic transmission

US6835147B2 · kind B2 · utility

14Cited by
5References
19Claims
0Family size

Assignees

Inventors

Key dates

Filing dateOct 2, 2002
Grant dateDec 28, 2004
Priority date
Expiry dateFeb 5, 2023

Classification

  • Technology area (CPC F)Mechanical Engineering; Lighting; Heating
  • CPC primaryF16H2061/6608
  • WIPO fieldMechanical elements
  • WIPO sectorMechanical engineering

Abstract

A hydraulic controller of an automatic transmission which releases the lockup clutch when it fails. An output port of a solenoid valve is connected to a port of a lockup control valve and a port of a garage shift valve. An output port of a solenoid valve is connected to a port of the lockup control valve and a port of the garage shift valve. At least one of the solenoid valves is freely duty-controlled. A pattern, which enables regular control of the automatic transmission in normal operation and does not allow the lockup clutch to change from its released state to its engaged state, is selected for use from among plural combinations of signal pressures of the solenoid valves.

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