Hydraulic pressure control for continuously variable transmission
US6849030B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 28, 2003 |
| Grant date | Feb 1, 2005 |
| Priority date | — |
| Expiry date | Aug 28, 2023 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF16H2312/02
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
A belt type continuously variable transmission (CVT) (10) for a vehicle varies the speed ratio in accordance with the hydraulic pressure that is regulated via a hydraulic pressure regulating unit (30). A sensor (27) detects a vehicle speed. A CVT controller (20) calculates a target hydraulic pressure that is supplied to the CVT (10) on the basis of a predetermined speed change schedule so that the speed ratio varies in the direction of up-shifting as the vehicle speed increases (S15). The CVT controller (20) also determines whether or not a specified condition holds (S16, S160), and controls the hydraulic pressure regulating unit according to a target start-up hydraulic pressure which is larger than a target hydraulic pressure for normal running (S11, S13), thereby preventing a speed change lag when the vehicle starts to move.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.