INTERMITTENT RESTART FOR AUTOMATIC ENGINE STOP START SYSTEM

• US 20180223788A1
• Filed: 04/04/2018
• Published: 08/09/2018
• Est. Priority Date: 11/02/2016
• Status: Active Grant

• Current Assignee: PACCAR Incorporated
• Original Assignee: PACCAR Incorporated
• Inventors: Gerty, Michael D., Vadlamani, Uday, Mosher, Jordan, Tuteja, Sundeep S., Nedelcu, Constantin E.
• Granted Patent: US 10,451,022 B2
• Time in Patent Office: Days
• CPC Class Codes: F02N 11/006 using a plurality of electric motors
• CPC Class Codes: F02N 11/0818 Conditions for starting or stopping the engine or for deactivating the idle-start-stop mode
• CPC Class Codes: F02N 11/0822 related to action of the driver
• CPC Class Codes: F02N 11/0844 with means for restarting the engine directly after an engine stop request, e.g. caused by change of driver mind
• CPC Class Codes: F02N 19/004 Aiding engine start by using decompression means or variable valve actuation
• CPC Class Codes: F02N 2200/022 Engine speed
• CPC Class Codes: F02N 2200/0801 Vehicle speed
• CPC Class Codes: F02N 2200/0808 Steering state, e.g. state of power assisted steering
• CPC Class Codes: F02N 2200/101 Accelerator pedal position
• CPC Class Codes: F02N 2200/102 Brake pedal position
• CPC Class Codes: F02N 2200/103 Clutch pedal position
• CPC Class Codes: F02N 2300/2002 using different starting modes, methods, or actuators depending on circumstances, e.g. engine temperature or component wear
• CPC Class Codes: F02N 2300/2011 Control involving a delay; Control involving a waiting period before engine stop or engine start
• CPC Class Codes: Y02T 10/40 Engine management systems

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.

Claims

1. 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.

2. The method of claim 1, wherein the step initiating an engine shutdown comprises stopping a fuel supply to the engine.

3. The method of claim 2, wherein the step initiating an engine shutdown further comprising activating a decompression device to decompress at least one cylinder of the engine.

4. The method of claim 3, 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.

5. The method of claim 4, 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.

6. The method of claim 3, 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.

7. The method of claim 6, wherein the auxiliary motor is an electric motor.

8. The method of claim 6, wherein the auxiliary motor is operably coupled to the engine by a clutch.

9. The method of claim 6, wherein the auxiliary motor is operably coupled to one of a power take off and a front end accessory drive.

10. The method of claim 6, 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.

11. The method of claim 1, wherein the restart request is made by an operator at least one of pressing a clutch, pressing an accelerator, and turning a steering wheel.

12. The method of claim 1, wherein a vehicle ignition remains on during engine shutdown.

13. The method of claim 1, wherein predetermined engine speed threshold is 300 rpm.

14. 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.

15. The system of claim 14, 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.

16. The system of claim 15, 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.

17. The system of claim 16, 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.

18. The method of claim 17, 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.

19. The system of claim 15, 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.

20. The method of claim 19, 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.