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US 2017/0254283 A1Published application
Method and system for exhaust catalyst warming
AssigneeFord Global Technologies, LLC
InventorChris Paul Glugla
Life of this patent
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Abstract
Methods and systems are provided for leveraging engine skip-fire operation during an engine cold-start to expedite catalyst heating. Based on the heat flux required, the engine may be operated with a group of cylinders selectively deactivated, with spark retard on remaining active cylinders increased, and with engine speed increased to reduce NVH issues during the skip-fire operation. The combination of parameters may be adjusted based on changes in exhaust temperature and NVH limits of the engine.
Claims7
1-14. (canceled)
An engine system, comprising:
- an engine including a plurality of cylinders;
- an exhaust catalyst;
- a temperature sensor coupled to an engine exhaust;
- an accelerometer coupled to an engine block for estimating engine vibration;
- electrically actuated cylinder valve mechanisms coupled to each of the plurality of cylinders;
- a selectively deactivatable fuel injector coupled to each of the plurality of cylinders;
- and
- an engine controller configured with computer readable instructions stored on non-transitory memory for:
- during an engine cold-start,
- estimating a heat flux required to activate the exhaust catalyst;
- and
- based on the estimated heat flux,
- deactivating individual cylinder valve mechanisms for one or more of the plurality of cylinders according to a pattern, the pattern including a total number of deactivated to active cylinders and an order of firing of active cylinders;
- operating the active cylinders with an amount of spark retard based on the estimated heat flux and the pattern;
- and
- adjusting an engine speed during the cold-start based on the pattern and the amount of spark retard.
13 more elements
Dependencies are inferred from the claim text.