Method and apparatus for operating an internal combustion engine exhaust valve for braking
AssigneeCaterpillar Inc.
InventorsClifford E. Cotton III, Richard H. Holtman, Larry G. Waterfield
Life of this patent
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Abstract
An exhaust valve apparatus for an internal combustion engine exhaust valve having a thermally prestressed bender actuator, which moves through a displacement in response to a command signal from a control unit. An actuator drive responsive to motion of the thermally prestressed bender actuator operates an exhaust valve actuator system, which, in turn, operates the exhaust valve. The thermally prestressed electroactive bender actuator and the exhaust valve actuator system operate the exhaust valve to effect engine compression braking.
Claims29
An apparatus for operating an exhaust valve of an internal combustion engine to provide engine compression braking, the apparatus comprising:
- a thermally prestressed electroactive bender actuator operable to receive a command signal indicative of engine compression braking and operable to move between first and second positions as a function of the command signal;
- and
- an exhaust valve actuator system coupled with the thermally prestressed electroactive bender actuator and the exhaust valve, the exhaust valve actuator system operable to operate the exhaust valve as a function of the thermally prestressed electroactive bender actuator moving between the first and second positions, the thermally prestressed electroactive bender actuator and the exhaust valve actuator system operable to operate the exhaust valve to effect engine compression braking.
An apparatus for operating an exhaust valve of an internal combustion engine in response to command signals to provide engine compression braking, the apparatus comprising:
- a thermally prestressed electroactive bender actuator operable to move through displacements in two different directions as a function of the command signals;
- and
- an exhaust valve actuator system coupled with the thermally prestressed electroactive bender actuator operable to operate the exhaust valve, the exhaust valve actuator system operating the exhaust valve as a function of the thermally prestressed electroactive bender actuator moving through the displacements, the thermally prestressed electroactive bender actuator and the exhaust valve actuator system operable to operate the exhaust valve to effect engine compression braking.
An apparatus for operating an exhaust valve of an internal combustion engine in response to a command signal to provide engine compression braking, the apparatus comprising:
- a control unit operable to provide a plurality of command signals indicative of engine braking;
- a thermally prestressed electroactive bender actuator electrically connected with the control unit to receive the plurality of command signals, the thermally prestressed bender actuator operable to move through a plurality of displacements in two different directions as a function of the command signals;
- and
- an exhaust valve actuator system coupled with the thermally prestressed electroactive bender actuator and the exhaust valve, the exhaust valve actuator system operable to operate the exhaust valve as a function of the thermally prestressed electroactive bender actuator moving through the plurality of displacements, the thermally prestressed electroactive bender actuator and the exhaust valve actuator system operable to operate the exhaust valve to effect engine compression braking.
A method of operating an exhaust valve of an internal combustion engine in response to a command signal to provide engine compression braking, the method comprising:
- applying the command signal to a thermally prestressed electroactive bender actuator;
- switching the thermally prestressed electroactive bender actuator between first and second operating states as a function of the command signal;
- and
- switching a exhaust valve actuator system between first and second operating states as a function of the thermally prestressed electroactive bender actuator switching between the first and the second operating states, the exhaust valve actuator system operating the exhaust valve as a function of the exhaust valve actuator system switching between the first and the second operating states, the thermally prestressed electroactive bender actuator and the exhaust valve actuator system operating the exhaust valve to effect engine compression braking.
A method of operating an exhaust valve of an internal combustion engine in response to command signals to provide engine compression braking, the method comprising:
- applying a first command signal to a thermally prestressed electroactive bender actuator;
- moving the thermally prestressed electroactive bender actuator through a displacement in a first direction as a function of the first command signal;
- and
- supplying a pressurized fluid to an exhaust valve actuator system as a function of the thermally prestressed electroactive bender actuator moving through the displacement in the first direction, the pressurized fluid operable to cause the exhaust valve to open, the thermally prestressed electroactive bender actuator and the exhaust valve actuator system operating the exhaust valve to effect engine compression braking.
Dependencies are inferred from the claim text.