Cylinder deactivation engine with advanced exhaust cam timing and method
US6513471B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | Feb 6, 2002 |
| Grant date | Feb 4, 2003 |
| Priority date | — |
| Expiry date | Feb 6, 2022 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF01L2305/00
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
An engine has switching valve actuators with positive valve lash for actuating or deactivating valves of deactivation cylinders and conventional valve actuators with negligible valve lash for actuating valves of conventional cylinders. Cams for the deactivation cylinders have increased opening and closing ramps relative to cams of the conventional cylinders. This can lead to poor combustion quality at idle and light loads and result in perceived engine roughness by an operator. To compensate for this, timing of exhaust cams of the deactivation cylinders is advanced relative to those of the conventional cylinders to reduce valve overlap of the deactivation cylinders to sufficiently near that of the conventional cylinders to provide stable combustion at idle in both conventional and deactivation cylinders with nearly equivalent power operation of all the cylinders.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.