Tappet assembly for valve lift profile modification
AssigneeCummins Inc.
InventorAdam C. Cecil
Life of this patent
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Abstract
A valve train assembly is provided for modifying a lift of at least one intake valve and/or exhaust valve. The valve train assembly includes at least one tappet that is housed in a rocker housing with at least one rocker lever. The at least one tappet is engaged to an actuator that is operable to change the tappet from a first configuration in which all cam lobe motion is imparted to the rocker lever for opening and closing the intake and/or exhaust valve, to a second configuration in which less than all motion of the cam lobe is transferred to the rocker lever.
Claims19
An internal combustion engine system, comprising:
- a cylinder housing a piston operably connected to a crankshaft, the cylinder further including at least one intake valve and at least one exhaust valve for selectively opening and closing respective ones of at least one intake opening and at least one exhaust opening of the cylinder;
- a camshaft including a first cam lobe and a second cam lobe, the first and second cam lobes being rotatable with rotation of the camshaft;
- and
- a valve lifting mechanism linking the first and second cam lobes to respective ones of the at least one intake valve and the at least one exhaust valve, the valve lifting mechanism including a first tappet linking the at least one intake valve to the first cam lobe and a second tappet linking the at least one exhaust valve to the second cam lobe, the valve lifting mechanism including a single actuator that simultaneously reconfigures the first and second tappets from a first configuration in which all motion from the first and second cam lobes is imparted to the linked at least one intake valve and at least one exhaust valve, to a second configuration in which less than all motion from the first and second cam lobes is imparted to the linked at least one intake valve and at least one exhaust valve.
A tappet for modifying a valve lift in a valve train system for an internal combustion engine, comprising:
- an elongated inner body housed within an outer body, wherein the inner body and the outer body include a locked configuration in which the inner body and the outer body are axially locked relative to one another in order to provide a first valve lift in response to a cam lobe profile acting on the tappet, the inner body and the outer body being rotated axially relative to one another to an unlocked configuration in which the inner body and the outer body are axially movable relative to one another to provide a second valve lift in response to the cam lobe profile acting on the tappet, the second valve lift being less than the first valve lift.
A valve train system for an internal combustion engine, comprising:
- a rocker housing, at least one tappet positioned within the rocker housing, and a rocker lever in the rocker housing positioned around and in direct contact with the at least one tappet to pivot the rocker lever in response to a valve lift, the at least one tappet being configured for operation in a first mode and in a second mode, wherein in the first mode the at least one tappet is configured to transfer a first valve lift in response to a cam lobe profile acting on the at least one tappet, and in the second mode the at least one tappet is configured to transfer a second valve lift in response to the cam lobe profile acting on the at least one tappet, the second valve lift being less than the first valve lift.
Dependencies are inferred from the claim text.