Engine valve timing control system and method
US5503120A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 18, 1995 |
| Grant date | Apr 2, 1996 |
| Priority date | — |
| Expiry date | Jan 18, 2015 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF01L2013/0089
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
A simplified lost motion valve control system and method for engines combines a cam, having a seating ramp located between lift and return profiles of the cam lobe, with a simplified hydraulic actuator having follower and actuator pistons and a fluid discharge passage that is internally cut off by the actuator piston when the valve is close to its seated position. After opening of the valve by the cam through the actuator to a desired valve opening, the valve is closed by opening a solenoid valve to discharge fluid from the actuator until the valve closes to near its seated position. The valve is then seated by the actuator following the cam seating ramp. The actuator is refilled upon return of the follower piston along the cam return profile to the base circle. Exemplary embodiments of hydraulic actuators are disclosed as is a system including control of dual actuators, driven by out of phase cams, through a single solenoid valve alternately isolated by the discharge port closure of the actuator pistons.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.