Intermittent restart for automatic engine stop start system

Patent metadata

Field	Value
Publication number	US-10451022-B2
Application number	US-201815945070-A
Country	US
Kind code	B2
Filing date	Apr 4, 2018
Priority date	Nov 2, 2016
Publication date	Oct 22, 2019
Grant date	Oct 22, 2019

Abstract

A disclosed method of automatically stopping and restarting a vehicle engine determines if one or more stop/start enablement condition has been met. If the stop/start enablement condition or conditions have been met, the method initiates an engine shutdown. If a restart request is made before the engine reaches a predetermined threshold speed, then a first restart sequence is initiated. If a restart request is made when the engine speed is less than the predetermined threshold speed but still greater than 0, then a second restart sequence is initiated.

First claim

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A stop/restart system for a vehicle, comprising:
(a) a vehicle having an engine;
(b) an engine speed sensor configured to sense engine speed; and
(c) a controller configured to receive signals from the engine speed sensor and to control delivery of fuel to the engine, wherein the controller is programmed to:
(i) determine if a stop/start enablement condition has been met;
(ii) initiate an engine shutdown;
(iii) initiating a first intermittent engine restart process in response to the restart request when engine speed is greater than the predetermined threshold speed; and
(iv) initiate a second intermittent engine restart process in response to the restart request when engine speed is greater than 0 and less than the predetermined threshold speed.

2. The system of claim 1 , wherein the controller is programmed to control the system to perform the steps of:
(a) stopping a fuel supply to the engine during the step initiating an engine shutdown;
(b) activating a decompression device to decompress at least one cylinder of the engine during the step of initiating an engine shutdown; and
(c) comparing an engine speed to a predetermined engine speed threshold during the step of initiating an intermittent engine restart.

3. The system of claim 2 , wherein initiating the first intermittent engine restart process comprises the steps of:
(a) deactivating the decompression device, and
(b) restoring the fuel supply to the engine.

4. The system of claim 3 , wherein initiating the second intermittent engine restart process comprises the steps of:
(a) driving the engine with an auxiliary motor;
(b) deactivating the decompression device, and
(c) restoring the fuel supply to the engine.

5. The system of claim 4 , further comprising the step of initiating a third intermittent engine restart process in response to the restart request when engine speed=0, wherein the third intermittent engine restart process comprises the step of driving the engine with the auxiliary motor.

6. The system of claim 2 , wherein initiating the second intermittent engine restart process comprises the steps of:
(a) driving the engine with an auxiliary motor;
(b) deactivating the decompression device, and
(c) restoring the fuel supply to the engine.

7. The system of claim 6 , further comprising the step of initiating a third intermittent engine restart process in response to the restart request when engine speed=0, wherein the third intermittent engine restart process comprises the step of driving the engine with the auxiliary motor.

8. A method of automatically stopping and restarting a vehicle engine, comprising the steps of:
(a) determining if a stop/start enablement condition has been met;
(b) initiating an engine shutdown;
(c) receiving a restart request;
(d) initiating a first intermittent engine restart sequence in response to the restart request when engine speed is greater than the predetermined threshold speed; and
(e) initiating a second intermittent engine restart sequence in response to the restart request when engine speed is greater than 0 and less than the predetermined threshold speed.

9. The method of claim 8 , wherein the step initiating an engine shutdown comprises stopping a fuel supply to the engine.

10. The method of claim 9 , wherein the step initiating an engine shutdown further comprising activating a decompression device to decompress at least one cylinder of the engine.

11. The method of claim 10 , wherein the first intermittent engine restart sequence comprises the steps of:
(a) deactivating the decompression device, and
(b) restoring the fuel supply to the engine.

12. The method of claim 11 , wherein the second intermittent engine restart sequence comprises the steps of:
(a) driving the engine with an auxiliary motor;
(b) deactivating the decompression device, and
(c) restoring the fuel supply to the engine.

13. The method of claim 10 , wherein the second intermittent engine restart sequence comprises the steps of:
(a) driving the engine with an auxiliary motor;
(b) deactivating the decompression device, and
(c) restoring the fuel supply to the engine.

14. The method of claim 13 , wherein the auxiliary motor is an electric motor.

15. The method of claim 13 , wherein the auxiliary motor is operably coupled to the engine by a clutch.

16. The method of claim 13 , wherein the auxiliary motor is operably coupled to one of a power take off and a front end accessory drive.

17. The method of claim 13 , further comprising the step of initiating a third intermittent engine restart sequence in response to the restart request when engine speed=0, wherein the third intermittent engine restart sequence comprises the step of driving the engine with the auxiliary motor.

18. The method of claim 8 , wherein the restart request is made by an operator at least one of pressing a clutch, pressing an accelerator, and turning a steering wheel.

19. The method of claim 8 , wherein a vehicle ignition remains on during engine shutdown.

20. The method of claim 8 , wherein predetermined engine speed threshold is 300 rpm.

Assignees

• Gerty Michael D
• Vadlamani Uday
• Mosher Jordan
• Tuteja Sundeep S
• Nedelcu Constantin E
• Paccar Inc

Inventors

• Gerty Michael D
• Vadlamani Uday
• Mosher Jordan
• Tuteja Sundeep S
• Nedelcu Constantin E

Classifications

• F02N19/004

  Aiding engine start by using decompression means or variable valve actuation · CPC title

• F02N2200/0808

  Steering state, e.g. state of power assisted steering · CPC title

• F02N2200/102

  Brake pedal position · CPC title

• F02N11/0818

  Conditions for starting or stopping the engine or for deactivating the idle-start-stop mode · CPC title

• F02N11/006

  using a plurality of electric motors · CPC title