Method for powertrain operation

Patent metadata

Field	Value
Publication number	US-9677527-B2
Application number	US-201514620981-A
Country	US
Kind code	B2
Filing date	Feb 12, 2015
Priority date	Feb 12, 2014
Publication date	Jun 13, 2017
Grant date	Jun 13, 2017

Abstract

A method for starting and operating an engine of a mild hybrid vehicle following start-up is disclosed for an engine having low and high voltage starting devices, and controlled by an electronic controller. The method comprises using the high voltage starting device as a motor to crank the engine whenever possible so as to partially discharge a high voltage battery. The method further comprises using the high voltage starting device as a generator after starting the engine if the exhaust gas temperature needs to be increased so as to assist with light-off of one or more exhaust gas after treatment devices.

First claim

What is claimed is:

1. A method comprising:
starting an engine of a vehicle having a starter motor and a belt integrated starter-generator (BISG) outside a torque path between the engine and wheels using only the BISG if engine temperature is greater than a predefined temperature limit; and
if after the starting it is required to activate an exhaust after treatment device, using the BISG as a generator to load the engine to increase engine exhaust gas temperature.

2. The method as claimed in claim 1 further comprising using the BISG as a generator to increase the engine exhaust gas temperature until it is no longer required to increase the engine exhaust gas temperature.

3. The method as claimed in claim 1 further comprising using the BISG as a generator only if a state of charge of a battery charged by the BISG is less than a predefined upper charging limit.

4. The method as claimed in claim 1 further comprising, if after the starting it is not required to activate the exhaust after treatment device, using the BISG as a motor to provide torque assist to the engine if torque assist is required.

5. The method as claimed in claim 4 further comprising using the BISG as a motor to provide torque assist only if a state of charge of a battery providing power to the BISG is greater than a minimum permitted charge level.

6. The method as claimed in claim 1 , wherein the predefined temperature limit falls within a range of −40 to +5 degrees Celsius.

7. A method comprising:
starting an engine of a vehicle having a starter motor and a belt integrated starter-generator (BISG) outside a torque path between the engine and wheels using only the BISG to reduce a state of charge (SOC) of a battery used to power the BISG; and
if after the starting it is required to activate an exhaust after treatment device and the SOC is less than a predefined level, using the BISG as a generator to load the engine to increase engine exhaust gas temperature.

8. The method as claimed in claim 7 further comprising using the BISG as a generator to increase the engine exhaust gas temperature until it is no longer required to increase the engine exhaust gas temperature.

9. The method as claimed in claim 7 further comprising, if after the starting it is not required to activate the exhaust after treatment device, using the BISG as a motor to provide torque assist to the engine if torque assist is required.

10. The method as claimed in claim 7 further comprising using the BISG as a motor to provide torque assist only if the SOC is greater than a minimum permitted charge level.

Assignees

• Ford Global Tech Llc

Inventors

• Kees Donatus Andreas Josephine
• Petridis Anthemios Philemon

Classifications

• F02N11/00

  Starting of engines by means of electric motors · CPC title

• B60W30/194 Primary

  related to low temperature conditions, e.g. high viscosity of hydraulic fluid · CPC title

• F02N2200/041

  Starter speed · CPC title

• F02N11/006 Primary

  using a plurality of electric motors · CPC title

• F02N2200/122

  Atmospheric temperature · CPC title