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US 2015/0285161 A1Published application
Method and system for engine control
AssigneeFord Global Technologies, LLC
InventorsJoseph Norman Ulrey, John Eric Rollinger, Michael Howard Shelby, Jianwen James Yi
Life of this patent
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Abstract
Methods and systems are provided for using compression heating to heat a cylinder piston before cylinder combustion is resumed. Cylinder heating is achieved using combinations of slow unfueled engine rotation where the engine cylinders are heated via compression stroke heating, and slow compressor rotation where the cylinders are heated via compression heating. One or more intake or exhaust heaters may be concurrently operated to expedite cylinder heating.
Claims20
A method, comprising:
- while propelling a hybrid vehicle via motor torque, rotating an electrically-actuated intake compressor with an upstream intake throttle closed and an EGR valve open until a piston temperature is above a threshold.
A method, comprising:
- while propelling a hybrid vehicle via only motor torque,
- rotating an engine unfueled via the motor torque at lower than engine cranking speed while operating an exhaust heater coupled to an exhaust catalyst and while holding an EGR valve open and an upstream intake throttle closed to recirculate heated aircharge through the engine.
A hybrid vehicle method, comprising:
- in response to a piston temperature being less than a threshold while the vehicle is propelled via motor torque only,
- during a first condition, rotating the engine unfueled via the motor torque at less than cranking speed to sequentially heat all engine cylinders as they pass through a compression stroke;
- and
- during a second condition, rotating an electrically-actuated intake compressor with a compressor recirculation valve held open.
1 more element
Dependencies are inferred from the claim text.