Variable valve timing control apparatus for engine
AssigneeDenso Corporation
InventorYasuo Hirata
Life of this patent
Estimating the term…
Abstract
A variable valve timing control apparatus includes a variable valve timing device and a valve timing controller to control the variable valve timing device in a manner that an actual VCT phase coincides with a target VCT phase. When the target VCT phase is set into a predetermined phase, learning means learn the predetermined phase as a reference phase. When determining means determine that there is a learning requirement of the reference phase, enlarging means enlarge an engine operation area where the target VCT phase is set into the reference phase by shifting the target VCT phase to the reference phase in an area where the target VCT phase is close to the reference phase.
Claims20
A variable valve timing control apparatus for an engine comprising:
- a variable valve timing device to change valve timing of an intake valve or an exhaust valve by changing a rotation phase of a camshaft relative to a crankshaft, the rotation phase of the camshaft being defined as a variable cam timing (VCT) phase;
- a valve timing controller to control the variable valve timing device in a manner that an actual VCT phase coincides with a target VCT phase;
- means for learning a reference phase when the target VCT phase is set into a predetermined phase corresponding to the reference phase;
- means for determining whether there is a learning requirement of the reference phase;
- and
- means for enlarging an engine operation area where the target VCT phase is set into the reference phase by shifting the target VCT phase to the reference phase in an area where the target VCT phase is close to the reference phase when the determining means determine that there is the learning requirement of the reference phase;
- wherein the determining means whether there is the learning requirement of the reference phase based on a learning state of the reference phase.
A variable valve timing control apparatus for an engine comprising:
- a variable valve timing device to change valve timing of an intake valve or an exhaust valve by changing a rotation phase of a camshaft relative to a crankshaft, the rotation phase of the camshaft being defined as a variable cam timing (VCT) phase;
- and
- an electronic control unit, comprising a computer, the electronic control unit being configured to at least:
- control the variable valve timing device in a manner that an actual VCT phase coincides with a target VCT phase;
- learn a reference phase when the target VCT phase is set into a predetermined phase corresponding to the reference phase;
- determine whether there is a learning requirement of the reference phase based on a learning state of the reference phase;
- and
- enlarge an engine operation area where the target VCT phase is set into the reference phase by shifting the target VCT phase to the reference phase in an area where the target VCT phase is close to the reference phase when a determination is made that there is the learning requirement of the reference phase.
Dependencies are inferred from the claim text.