ENGINE STOP/START SYSTEM AND METHOD OF OPERATING SAME

• US 20090224557A1
• Filed: 09/03/2008
• Published: 09/10/2009
• Est. Priority Date: 03/07/2008
• Status: Active Grant

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: GM Global Technology Operations Incorporated (General Motors Company)
• Inventors: Albertson, William C., Reynolds, Michael G.
• Granted Patent: US 8,561,588 B2
• Time in Patent Office: Days
• US Class Current: 290/38.R
• CPC Class Codes: F02N 11/0814 comprising means for controlling automatic idle-start-stop
• CPC Class Codes: F02N 11/0855 during engine shutdown or after engine stop before start command, e.g. pre-engagement of pinion
• CPC Class Codes: F02N 15/023 of the overrunning type
• CPC Class Codes: F02N 15/067 the starter comprising an electro-magnetically actuated lever
• CPC Class Codes: F02N 2200/022 Engine speed
• CPC Class Codes: F02N 2250/04 Reverse rotation of the engine
• CPC Class Codes: Y02T 10/40 Engine management systems

Abstract

A method of operating an engine stop/start system includes connecting an armature of a starter motor to the engine through an overrunning clutch when the engine changes a rotational direction.

Claims

1. A method of operating an engine stop/start system comprising:

connecting an armature of a starter motor to the engine when the crankshaft starts to change a rotational direction.

2. The method of claim 1 wherein connecting the armature of the starter motor to the engine by using a mechanical overrunning clutch.

3. The method of claim 2 wherein the mechanical overrunning clutch is engaged when the crankshaft starts to rotate in a reverse direction.

4. The method of claim 1 further comprising coupling a starter motor through a mechanical overrunning clutch to the engine before an engine speed becomes zero.

5. The method of claim 4 further wherein the mechanical overrunning clutch is disengaged before the engine speed becomes zero.

6. The method of claim 4 wherein the mechanical overrunning clutch is engaged at crankshaft reversal.

7. The method of claim 1 wherein the starter motor is electrically deactivated.

8. The method of claim 1 further comprising moving a pinion gear of the starter motor to engage a flywheel ring gear of the engine after the engine is commanded to stop and when the engine is at a predetermined engine speed.

9. The method of claim 8 wherein the predetermined engine speed is in a range of above zero and below 200 RPM.

10. The method of claim 8 further comprising maintaining engagement between the pinion gear and the flywheel ring gear after the engine is shut off.

11. An engine stop/start control system comprising:

an engine speed sensor that measures an engine speed; and

an engine damping module that communicates with an engine speed sensor and that is activated after the engine is commanded to stop; and

a solenoid control module that controls a solenoid to couple a starter motor to an engine when the engine damping module determines that the engine is slowed to a predetermined engine speed.

12. The engine stop/start control system of claim 11 wherein the starter motor includes a mechanical overrunning clutch that connects an armature of the starter motor to the engine when the crankshaft changes rotational direction.

13. The engine stop/start control system of claim 12 wherein the mechanical overrunning clutch is coupled to a pinion gear.

14. The engine stop/start control system of claim 13 wherein the solenoid control module controls the solenoid to move the pinion gear to engage a flywheel ring gear of the engine after the engine is commanded to stop and when the engine is at a predetermined engine speed.

15. The engine stop/start control system of claim 14 wherein the predetermined engine speed is in a range of above zero and below 200 RPM.

16. The engine stop/start control system of claim 11 further comprising a motor control module that selectively actuates and de-actuates a starter motor, wherein the starter motor and the solenoid are controlled independently and separately.