Methods and system for operating an exhaust valve of an internal combustion engine
AssigneeFord Global Technologies, LLC
InventorsDouglas Raymond Martin, John Eric Rollinger
Life of this patent
Estimating the term…
Abstract
Systems and methods for operating exhaust valves of an internal combustion engine with poppet exhaust valves are described. The systems and methods provide for locking exhaust valves in a closed state when the exhaust valves are in mechanical communication with a base circle of a camshaft lobe. Locking the exhaust valves in a closed state may reduce the possibility of exhaust pressures opening the exhaust valves at times they may not be desired to be open.
Claims12
An engine operating method, comprising:
- locking an exhaust valve of a cylinder in a closed position via a mechanism other than a valve spring and including a pawl in response to the exhaust valve being in mechanical communication with a base circle of a camshaft lobe;
- and
- deactivating a cylinder in response to a misfire in the cylinder after the exhaust valve is commanded unlocked.
An engine operating method, comprising:
- locking an exhaust valve of a cylinder in a closed position via a mechanism other than a valve spring and including a pawl in response to the exhaust valve being in mechanical communication with a base circle of a camshaft lobe, where the locking of the exhaust valve allows rotation of the exhaust valve.
An engine system, comprising:
- an engine including an exhaust valve;
- a camshaft including a cam lobe, the camshaft in mechanical communication with the exhaust valve;
- and
- an exhaust valve locking device, the device including a pawl, in selective mechanical communication with the camshaft, the exhaust valve locking device in a position unlocking the exhaust valve when a ramp of the cam lobe is in contact with the exhaust valve locking device, where the exhaust valve locking device includes a C shaped locking pawl.
An engine system, comprising:
- an engine including an exhaust valve;
- a camshaft including a cam lobe, the camshaft in mechanical communication with the exhaust valve;
- an exhaust valve locking device, the device including a pawl, in selective mechanical communication with the camshaft, the exhaust valve locking device in a position unlocking the exhaust valve when a ramp of the cam lobe is in contact with the exhaust valve locking device;
- and
- a controller including non-transitory instructions stored in memory to deactivate a cylinder in response to degradation of the exhaust valve locking device.
Dependencies are inferred from the claim text.