Camshaft tone wheel, system, and method for determining engine speed and position
AssigneeCummins Inc.
InventorsDavid L. Baldwin, Matthew Shawn Bower, Xiaoyu Xie
Life of this patent
Estimating the term…
Abstract
A camshaft tone wheel, system, and method are provided for determining a rotational position of an internal combustion engine. Sensors detect unique features positioned around the camshaft tone wheel in conjunction with a tooth count on a crankshaft tone wheel, or in conjunction with elapsed time for passage of the unique features during rotation of the camshaft tone wheel, to resolve engine position and enable accurately timed combustion.
Claims20
An engine speed and position sensing system, the system comprising:
- a crankshaft tone wheel including a plurality of indicators positioned around the crankshaft tone wheel and at least one interruption in the plurality of indicators;
- a camshaft tone wheel including a plurality of binary features positioned around the camshaft tone wheel, wherein adjacent ones of the plurality of binary features each define one of a first transition or a second transition, the second transitions being located between adjacent ones of the first transitions, and the plurality of first transitions are located at unique angular spacings from one another about the camshaft tone wheel;
- a sensor arrangement operable to provide an output indicative of a passage of the plurality of indicators of the crankshaft tone wheel and a passage of the first and second transitions of the camshaft tone wheel;
- and
- a control unit configured to resolve an engine position in response to the passage of a number of the plurality of indicators of the crankshaft tone wheel that identifies at least one of the first and second transitions of the camshaft tone wheel.
A tone wheel for a camshaft, the tone wheel comprising:
- a circular member having a rotational center and a plurality of angular regions positioned around the rotational center, wherein each of the plurality of angular regions includes a pair of binary features with a transition between the pair of binary features that is uniquely positioned within the respective angular region in relation to a positioning of the transitions within the other angular regions.
A method for determining an engine position, the method comprising:
- sensing a transition between a pair of binary features of a camshaft tone wheel as the camshaft wheel rotates;
- determining a number of indicators of a rotating crankshaft tone wheel associated with the sensed transition;
- and
- resolving the engine position based on the number of indicators associated with the sensed transition.
Dependencies are inferred from the claim text.