Hydraulic circuit for a valve operating timing control device for an internal combustion engine
US4858574A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 24, 1987 |
| Grant date | Aug 22, 1989 |
| Priority date | — |
| Expiry date | Dec 24, 2007 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF02F2001/245
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
A hydraulic circuit for a valve operation timing control device for an internal combustion engine which has a low-speed cam having a shape suited for low-speed operation of the engine, a high-speed cam having a shape suited for high-speed operation of the engine, the low- and high-speed cams being integrally formed on a camshaft rotatable in synchronism with a crankshaft, a first rocker arm held in slidable contact with the low-speed cam, a second rocker arm held in slidable contact with the high-speed cam. The first and second rocker arms are adjacent to and in slidable contact with each other and pivotably supported on a rocker shaft for relative angular displacement. There is a first oil feed passage for lubricating the low-speed cam and a second oil feed passage for lubricating the high-speed cam. The first rocker arm has a hydraulic lash adjuster and a relief valve is disposed in the oil passage for supplying oil pressure to said hydraulic lash adjuster for maintaining a predetermined oil pressure on the hydraulic lash adjuster.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.