Variable-valve-actuation apparatus for internal combustion engine
AssigneesUnisia Jecs Corporation, Nissan Motor Co., Ltd.
InventorsMakoto Nakamura, Shinichi Takemura
Life of this patent
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Abstract
A VVA apparatus for an internal combustion engine includes a intake valve, and an alteration mechanism which variably controlling lift characteristics of the intake valve in accordance with the engine operating conditions, wherein the valve lift characteristics include a ramp period which is shorter in the range of medium lift amount than in the range of small lift amount and the range of large lift amount.
Claims19
A variable-valve-actuation (VVA) apparatus for an internal combustion engine, comprising:
- a valve;
- and
- a mechanism which variably controls lift characteristics of the valve in accordance with operating conditions of the engine,
- wherein the lift characteristics include a ramp period which is shorter in a range of medium lift amount than in a range of small lift amount and a range of large lift amount.
A variable-valve-actuation (VVA) apparatus for an internal combustion engine, comprising:
- a valve;
- and
- a mechanism which variably controlling lift characteristics of the valve in accordance with operating conditions of the engine, the mechanism comprising a driving shaft rotated in synchronism with a crankshaft, a crank cam fixed to the driving shaft, a cam arrangement swingably supported on the driving shaft for opening and closing the valve, a rocker arm swingably supported by the control shaft and having a first arm linked with the crank cam through a crank arm and a second arm linked with the cam arrangement, and a control mechanism which controls rotation of the control shaft in accordance with the engine operating conditions,
- wherein a contact position of a cam face of the cam arrangement with respect to the valve is varied by changing a rocking fulcrum of the rocker arm in accordance with rotation of the control shaft,
- wherein when the mechanism controls the valve lift characteristics to a medium lift, an angle formed by a line connecting an axis of the driving shaft and an axis of the crank cam and a line connecting the axis of the crank cam and an axis of an extension of the crank arm is established to be roughly 90° during the ramp period, and
- wherein the lift characteristics include a ramp period which is shorter in a range of medium lift amount than in a range of small lift amount and a range of large lift amount.
Dependencies are inferred from the claim text.