Electronic transmission control system for automotive vehicle with continuously variable automatic transmission
US6243638A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 23, 1999 |
| Grant date | Jun 5, 2001 |
| Priority date | — |
| Expiry date | Dec 23, 2019 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF16H61/66272
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
An electronic transmission control system for an automotive vehicle with a belt-type continuously variable automatic transmission comprises a transmission ratio control device including a first motor-driven oil pump supplying working pressure directly to a secondary pulley actuation chamber, and a second motor-driven oil pump supplying working pressure directly to a primary pulley actuation chamber and enabling working oil to come and go between the primary and secondary pulley actuation chambers therethrough. A first control section is provided for controlling the first motor-driven oil pump so that the actual secondary pulley pressure is adjusted to a target working pressure needed to hold a belt capacity of a drive belt, which belt capacity is defined as a capacity required for exerting a grip of the drive belt on primary and secondary pulleys. Also provided is a second control section which controls the second motor-driven oil pump by limiting a speed-change flow rate (or a speed-change velocity), so that the actual primary pulley pressure is prevented from reducing to below a lowest working pressure capable of holding the belt capacity.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.