Line pressure control apparatus for belt-drive continuously variable transmission
US7546196B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 4, 2005 |
| Grant date | Jun 9, 2009 |
| Priority date | — |
| Expiry date | Jul 18, 2027 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF16H61/66254
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
In a line pressure control apparatus of a belt-drive CVT, a shift is achieved by varying V- groove widths of primary and secondary pulleys by a differential pressure between primary and secondary pulley pressures, originating from line pressure. The differential pressure is created by bringing a shift actuator, such as a step motor, into a control position corresponding to a target transmission ratio. The target transmission ratio is calculated based on a theoretical transmission ratio based on engine-and-vehicle operating conditions, taking account of a hardware response delay and a disturbance. The target transmission ratio is converted into a reference-model operative position, corresponding to a reference-model number-of-steps of the shift actuator. An actual transmission ratio is converted into an actual-transmission-ratio related operative position. Line pressure is corrected in a manner so as to reduce the positional deviation between the reference-model operative position and the actual-transmission-ratio related operative position.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.