Variable valve timing control apparatus and method for engines
US6505586B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 3, 2000 |
| Grant date | Jan 14, 2003 |
| Priority date | — |
| Expiry date | Aug 26, 2020 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T74/2102
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
A variable valve timing control apparatus is constructed so as to supply hydraulic pressure to an unlocking chamber for unlocking a lock pin only from a retarding chamber. In cranking an engine, a hydraulic pressure control valve is controlled so as to supply the hydraulic pressure only to an advancing chamber and so as not to apply the hydraulic pressure to the unlocking chamber. Thereby, the lock pin is prevented from being unlocked in cranking the engine in advance. After that, control current of a solenoid of the hydraulic pressure control valve is switched to hold current for holding the position of the camshaft phase at the point of time when a time necessary for enabling to supply the hydraulic pressure sufficient to control the camshaft phase from the completion of cranking to supply the hydraulic pressure equally to the both advancing and retarding chambers. Thereby, the hydraulic pressure is supplied also to the unlocking chamber from the retarding chamber and the lock pin is unlocked.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.