VCT cam timing system utilizing calculation of intake phase for dual dependent cams
AssigneeBorgWarner Inc.
InventorsEarl Ekdahl, Stanley B. Quinn, Jr.
Life of this patent
Estimating the term…
Abstract
An engine with dependent intake cams requires a different method and formula to determine the phase of the intake cams. The exhaust camshaft drives the intake camshaft and so the intake cam position is dependent upon the exhaust cam position. The present invention provides a VCT cam timing system utilizing calculation of intake phase for dual dependent cams.
Claims7
A variable cam timing (VCT) system used in an internal combustion engine, said system having a dual dependent cam shaft configuration, wherein an intake cam position is referenced to an exhaust cam, comprising:
- a sequence of crank tooth signals generated by a first position sensor;
- a sequence of exhaust cam tooth signals generated by a second position sensor;
- a sequence of intake cam tooth signals generated by a third position sensor;
- a formula of intake phase degrees referenced to the exhaust cam phase, said formula being:
- Phase=(ΔT/T*Crank Angle)−Zphase
- wherein ΔT is the time segment starting from a falling edge of said exhaust cam tooth signal to the next occurring falling edge of said intake cam tooth signal.
In a variable cam timing (VCT) system used in an internal combustion engine, said system having a dual dependent cam shaft configuration, wherein an intake cam position is referenced to an exhaust cam, a method comprising the steps of:
- providing a sequence of crank tooth signals generated by a first position sensor;
- providing a sequence of exhaust cam tooth signals generated by a second position sensor;
- providing a sequence of intake cam tooth signals generated by a third position sensor;
- providing a formula of intake phase degrees referenced to the exhaust cam phase, said formula being:
- Phase=(ΔT/T*Crank Angle)−Zphase
- wherein ΔT is the time segment starting from a falling edge of said exhaust cam tooth signal to the next occurring falling edge of said intake cam tooth signal.
Dependencies are inferred from the claim text.