Hydraulic valve lifter with operating control system
US6772719B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 10, 2003 |
| Grant date | Aug 10, 2004 |
| Priority date | — |
| Expiry date | Jul 10, 2023 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF01L1/24
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
In an operating system for a hydraulic valve clearance control element of an internal combustion engine, which includes a hydraulic fluid having a pressure that depends on the engine operating state and wherein the hydraulic clearance control element includes a pressure chamber in which a hydraulic fluid volume is maintained for adjusting the length of the hydraulic clearance control element and means for maintaining the fluid volume when, after engine shut down, the pressure of the hydraulic fluid supplied by an engine fluid pressure source drops below a certain value so as to maintain the hydraulic clearance control element at its operating length during engine shutdown, means are arranged on the hydraulic fluid supply line to the hydraulic valve clearance control element for releasing hydraulic fluid to reduce its pressure below the certain value immediately upon engine shut down to safely maintain the hydraulic clearance control elements at their operating length.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.