Internal-combustion engine with an electronically controlled hydraulic system for actuation of the valves and means for compensating changes in the operating conditions of the hydraulic
US6736092B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 20, 2003 |
| Grant date | May 18, 2004 |
| Priority date | — |
| Expiry date | May 20, 2023 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF01L2001/34446
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
In an internal-combustion engine equipped with an electronically controlled hydraulic system for variable actuation of the inlet and/or exhaust valves of the engine, the hydraulic system for actuation of the valves includes, for each engine valve, a solenoid valve for controlling the corresponding hydraulic actuator. Each solenoid valve is controlled according to a pre-set control criterion according to the operating parameters of the engine, said pre-set control criterion corresponding to reference operating conditions of the hydraulic fluid and, in particular, to the value of viscosity of the hydraulic fluid, which varies with temperature. The aforesaid control criterion is, however, adjusted according to an estimated deviation between reference operating conditions of the hydraulic fluid and actual operating conditions of the hydraulic fluid.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.