# US 9,039,571 B2 · Method and system for engine control

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- Number: US 9,039,571 B2
- Document ID: US9039571B2
- Status: Granted
- Kind: B2
- Application number: 13/025,922
- Filed: 2011-02-11
- Published: 2012-08-16
- Granted: 2015-05-26
- Earliest claimed: 2011-02-11
- Assignees: Ford Global Technologies, LLC
- Applicants: Jeffrey Allen Doering; Joseph Norman Ulrey; Alex O'Connor Gibson
- Inventors: Jeffrey Allen Doering; Joseph Norman Ulrey; Alex O'Connor Gibson
- Web page: https://patentgrep.com/patent/US9039571B2

## CPC

- F02D 9/00: Controlling engines by throttling air or fuel-and-air induction conduits or exhaust conduits
- F02D 13/0215: {changing the valve timing only}
- F02D 41/0002: {Controlling intake air}
- F02D 41/0025: {Controlling engines characterised by use of non-liquid fuels, pluralities of fuels, or non-fuel substances added to the combustible mixtures}
- F02D 41/0215: {in relation with elements of the transmission}
- F02D 41/042: {for stopping the engine}
- F02D 41/064: {at cold start (F02D41/067 takes precedence)}
- F02D 41/065: {at hot start or restart (F02D41/067 takes precedence)}
- B60W 10/04: including control of propulsion units
- B60W 30/18: Propelling the vehicle
- F01L 2800/03: Stopping; Stalling
- F02D 41/022: {in relation with the clutch status}
- F02D 2041/001: {for engines with variable valve actuation}
- F02D 2200/0414: Air temperature
- F02D 2200/703: Atmospheric pressure
- F02N 11/00: Starting of engines by means of electric motors
- F02N 11/0814: {comprising means for controlling automatic idle-start-stop}
- F02N 11/0822: {related to action of the driver}
- F02N 11/0844: {with means for restarting the engine directly after an engine stop request, e.g. caused by change of driver mind}
- F02N 15/006: {Assembling or mounting of starting devices}
- Y02T 10/40: Engine management systems
- F02D: CONTROLLING COMBUSTION ENGINES (vehicle fittings, acting on a single sub-unit only, for automatically controlling vehicle speed B60K31/00; conjoint control of vehicle sub-units of different type or different function, road vehicle drive control systems for purposes other than the control of a single sub-unit B60W)
- B60W: CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT
- F01L: CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES
- F02N: STARTING OF COMBUSTION ENGINES; STARTING AIDS FOR SUCH ENGINES, NOT OTHERWISE PROVIDED FOR
- Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION

## Abstract

Methods and systems are provided for controlling an engine system with a variable cam timing device. In one example, the variable cam timing device is operated to adjust engine valve timing differently at engine stop based on whether the engine stop is in response to an operator request or in response to an automatic controller initiated engine stop without an operator request.

## Claims

### Claim 1

A method of controlling an engine, comprising:
operating the engine with an intake valve closing timing;
adjusting the intake valve closing timing from the intake valve closing timing to a first timing in response to an operator requested engine stop; and
adjusting the intake valve closing timing from the intake valve closing timing to a second timing based on a transmission torque downstream of a torque converter and in response to an automatic controller requested engine stop.

### Claim 2 (depends on 1)

The method of claim 1, wherein the first timing is a timing where a larger amount of air is drawn into a cylinder of the engine during a restart of the engine as compared to the second timing.

### Claim 3 (depends on 1)

The method of claim 1, wherein the transmission torque is provided by engaging a gear clutch in response to the automatic controller requested engine stop.

### Claim 4 (depends on 3)

The method of claim 3, further comprising adjusting the intake valve closing timing to decrease cylinder air charge when the transmission torque is released or decreased.

### Claim 5 (depends on 1)

The method of claim 1, where the first and second timings are adjusted via an electrically-actuated variable cam timing device, and where the first and second timings are adjusted after the engine stops rotating.

### Claim 6 (depends on 1)

The method of claim 1, wherein the first and second timings are adjusted during rotation of the engine before an engine stop, and wherein the second timing is further adjusted responsive to a tie-up torque of a transmission in response to the automatic controller requested engine stop.

### Claim 7 (depends on 6)

The method of claim 6, wherein the second timing is further adjusted to a third timing in response to an engine speed less than a threshold engine speed.

### Claim 8 (depends on 1)

The method of claim 1, where the first timing is advanced or retarded from the second timing, and where the second timing is further adjusted in response to ambient temperature and pressure.

### Claim 9 (depends on 8)

The method of claim 8, wherein the second timing is further adjusted based on an alcohol concentration of a fuel injected to the engine.

### Claim 10

A method of controlling an engine, comprising:
adjusting a variable cam timing device to adjust intake valve timing in response to an automatic controller requested engine stop; and
adjusting the variable cam timing device to further adjust the intake valve timing responsive to a transmission input shaft speed downstream of a torque converter during engine stop.

### Claim 11 (depends on 10)

The method of claim 10, wherein the automatic controller requested engine stop includes an engine shutdown in response to idle-stop conditions and without receiving an operator request to stop the engine, and further comprising adjusting the intake valve timing responsive to a transmission tie-up torque.

### Claim 12 (depends on 10)

The method of claim 10, wherein a transmission is downshifted as a vehicle speed decreases in response to the automatic controller requested engine stop, and where the variable cam timing device is further adjusted responsive to the transmission input shaft speed downstream of the torque converter during an engine restart.

### Claim 13 (depends on 10)

The method of claim 10, wherein the variable cam timing device is adjusted to adjust the intake valve timing so that a cylinder air charge is increased for higher transmission input shaft speeds and decreased for lower transmission input shaft speeds, and further comprising engaging a transmission clutch in response to the automatic controller requested engine stop to provide a transmission tie-up torque, and adjusting the intake valve timing responsive to the tie-up torque.

### Claim 14 (depends on 10)

The method of claim 10, further comprising,
during a restart from the automatic controller requested engine stop, cranking the engine to restart the engine with the intake valve timing at a timing responsive to a desired engine idle speed.

### Claim 15 (depends on 14)

The method of claim 14, further comprising adjusting exhaust valve timing to limit air flow through an engine exhaust system, and adjusting intake valve timing when the engine is stopped while a vehicle in which the engine operates is decelerating in response to the transmission input shaft speed.

### Claim 16

A method of controlling an engine, comprising:
adjusting the intake valve closing timing during an engine stop based on a transmission torque downstream of a torque converter.

### Claim 17 (depends on 16)

The method of claim 16, where the transmission torque is produced via engaging a transmission gear clutch in response to an automatic controller requested engine stop, and where the transmission torque is a tie-up torque.