System for controlling a variable valve actuation system
First Claim
1. A method of controlling a valve actuation system for an engine, comprising:
- operating an intake cam assembly to move an intake valve between a first position where the intake valve blocks a flow of fluid relative to a cylinder and a second position where the intake valve allows a flow of fluid relative to the cylinder;
operating an exhaust cam assembly to move an exhaust valve between a first position where the exhaust valve blocks a flow of fluid and a second position where the exhaust valve allows a flow of fluid;
operating an engine brake to selectively move the exhaust valve from the first position towards the second position when a piston is at or near a top-dead-center position of a compression stroke;
sensing at least one operating parameter of the engine;
determining a desired intake valve actuation period based on the at least one operating parameter;
operating a valve actuator to selectively prevent the intake valve from returning to the first position in response to operation of the intake cam assembly; and
releasing the valve actuator to allow the intake valve to return to the first position at the end of the determined valve actuation period.
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Accused Products
Abstract
A method of controlling a valve actuation system is provided. An intake cam assembly is operated to move an intake valve between a first position and a second position. An exhaust cam assembly is operated to move an exhaust valve between a first position a second position. An engine brake is operated to selectively move the exhaust valve from the first position towards the second position when a piston is at or near a top-dead-center position of a compression stroke. At least one operating parameter of the engine is sensed. A desired intake valve actuation period is determined based on the at least one operating parameter. A valve actuator is engaged with the intake valve to prevent the intake valve from returning to the first position in response to operation of the intake cam assembly. The valve actuator is released to allow the intake valve to return to the first position at the end of the determined valve actuation period.
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Citations
20 Claims
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1. A method of controlling a valve actuation system for an engine, comprising:
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operating an intake cam assembly to move an intake valve between a first position where the intake valve blocks a flow of fluid relative to a cylinder and a second position where the intake valve allows a flow of fluid relative to the cylinder;
operating an exhaust cam assembly to move an exhaust valve between a first position where the exhaust valve blocks a flow of fluid and a second position where the exhaust valve allows a flow of fluid;
operating an engine brake to selectively move the exhaust valve from the first position towards the second position when a piston is at or near a top-dead-center position of a compression stroke;
sensing at least one operating parameter of the engine;
determining a desired intake valve actuation period based on the at least one operating parameter;
operating a valve actuator to selectively prevent the intake valve from returning to the first position in response to operation of the intake cam assembly; and
releasing the valve actuator to allow the intake valve to return to the first position at the end of the determined valve actuation period. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A valve actuation system for an engine, comprising:
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an intake valve moveable between a first position where the intake valve prevents a flow of fluid and a second position where the intake valve allows a flow of fluid;
an intake cam assembly connected to the intake valve to move the intake valve between the first position and the second position;
an exhaust valve moveable between a first position where the exhaust valve prevents a flow of fluid and a second position where the exhaust valve allows a flow of fluid;
an exhaust cam assembly connected to the exhaust valve to move the exhaust valve between the first position and the second position;
a brake actuator adapted to operatively engage the exhaust valve and to move the exhaust valve from the first position towards the second position;
a valve actuator adapted to operatively engage the intake valve and to prevent the intake valve from returning to the first position;
a sensor operable to sense an operating parameter of the engine; and
a controller operable to determine a valve actuation period based on the sensed operating parameter of the engine and to actuate the valve actuator to prevent the intake valve from returning to the first position for the determined valve actuation period. - View Dependent Claims (10, 11, 12, 13, 14)
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15. An engine, comprising:
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an engine block defining at least one cylinder;
a piston slidably disposed within the at least one cylinder to reciprocate between a bottom-dead-center position and a top-dead-center position;
an intake valve moveable between a first position where the intake valve prevents a flow of fluid to the at least one cylinder and a second position where the intake valve allows a flow of fluid to the at least one cylinder;
an intake cam assembly connected to the intake valve to move the intake valve between the first position and the second position;
an exhaust valve moveable between a first position where the exhaust valve prevents a flow of fluid and a second position where the exhaust valve allows a flow of fluid;
an exhaust cam assembly connected to the exhaust valve to move the exhaust valve between the first position and the second position;
a brake actuator adapted to operatively engage the exhaust valve and to move the exhaust valve from the first position towards the second position when the piston is approaching the top-dead-center position in a compression stroke;
a valve actuator adapted to operatively engage the intake valve and to prevent the intake valve from returning to the first position;
a sensor operable to sense an operating parameter of the engine; and
a controller operable to determine a valve actuation period based on the sensed operating parameter of the engine and to actuate the valve actuator to prevent the intake valve from returning to the first position for the determined valve actuation period. - View Dependent Claims (16, 17, 18, 19, 20)
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Specification