DEVICE FOR AUTOMATICALLY STOPPING AND RESTARTING INTERNAL COMBUSTION ENGINE

• US 20140345556A1
• Filed: 04/03/2012
• Published: 11/27/2014
• Est. Priority Date: 04/03/2012
• Status: Active Grant

• Current Assignee: Mitsubishi Electric Corporation
• Original Assignee: Mitsubishi Electric Corporation
• Inventors: Okabe, Takeru, Ishikawa, Osamu, Shoda, Tomohisa, Fujiwara, Michitaka
• Granted Patent: US 9,726,134 B2
• Time in Patent Office: Days
• US Class Current: 123/179.16
• CPC Class Codes: F02D 2200/101 Engine speed
• CPC Class Codes: F02D 29/02 peculiar to engines driving vehicles; peculiar to engines driving variable pitch propellers
• CPC Class Codes: F02N 11/0814 comprising means for controlling automatic idle-start-stop
• 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 11/101 for preventing engine starter actuation or engagement
• CPC Class Codes: F02N 2200/021 Engine crank angle
• 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 device for automatically stopping and restarting an internal combustion engine is provided with a crank angle sensor (1) that detects a crank angle of an engine (10), a fuel injection unit (11) that injects fuel into the engine, and the device is also provided with a starter activation prohibition determination means that prohibits activation of a starter (20) by determining that the engine is in reverse rotation during inertial rotation of the engine, and removes the starter activation prohibition depending on the crank angle when the engine starts reverse rotation.

Claims

1. A device for automatically stopping and restarting an internal combustion engine including

a fuel injection unit that injects fuel into an engine;

a crank angle sensor that detects a crank angle of the engine and outputs a crank angle signal;

a starter having a pinion gear that engages with a ring gear of the engine at start-up and transmits rotation to the ring gear; and

an engine control unit that controls the fuel injection unit and the starter;

wherein

the engine is automatically stopped when automatically stopping conditions are met and following that, the engine is restarted when restarting conditions are met;

the device for automatically stopping and restarting the internal combustion engine comprising a starter activation prohibition determination means that makes a determination of engine reverse rotation during inertial rotation of the engine, thereby prohibiting activation of the starter, and removes the starter activation prohibition depending on the crank angle when the engine starts reverse rotation.

2. A device for automatically stopping and restarting an internal combustion engine according to claim 1, wherein the starter activation prohibition determination means includes a minimum rotation speed detection means that detects a minimum rotation speed during the engine reverse rotation, and removes the starter activation prohibition at a timing of engine rotation speed becoming a predetermined tolerable rotation speed after the minimum rotation speed detection means has detected the minimum rotation speed during the engine reverse rotation.

3. A device for automatically stopping and restarting an internal combustion engine according to claim 2, wherein the minimum rotation speed detection means, when detecting a calculation value of the engine rotation speed increasing compared with the immediately preceding value, makes the immediately preceding value of the engine rotation speed the minimum value during the engine reverse rotation.

4. A device for automatically stopping and restarting an internal combustion engine according to claim 2, wherein the predetermined tolerable rotation speed is obtained from a factor deciding a contacting time for the pinion gear to contact the ring gear after the activation of the starter is started.

5. A device for automatically stopping and restarting an internal combustion engine according to claim 4, wherein the factor deciding the contacting time is a gap between the pinion gear and the ring gear or battery voltage.

6. A device for automatically stopping and restarting an internal combustion engine according to claim 1, wherein the crank angle sensor is a sensor capable of detecting the engine reverse rotation.

7. A device for automatically stopping and restarting an internal combustion engine according to claim 1, wherein

the crank angle sensor detects the crank angle when the engine starts reverse rotation,

the starter activation prohibition determination means includes a minimum rotation speed detection means that detects a minimum rotation speed during the engine reverse rotation, and if

the crank angle when the engine starts reverse rotation is smaller than a crank angle threshold value to make a determination of removing the starter activation prohibition, and the minimum value of the engine rotation speed during the engine reverse rotation is smaller than a lower limit of a range allowing starter shift, or

the crank angle when the engine starts reverse rotation is greater than the crank angle threshold value to make the determination of removing the starter activation prohibition, and the minimum value of the engine rotation speed during the engine reverse rotation is greater than the lower limit of the range allowing the starter shift,

the crank angle threshold value to make the determination of removing the starter activation prohibition is updated to the presently-detected crank angle when the engine starts reverse rotation.

8. A device for automatically stopping and restarting an internal combustion engine according to claim 7, wherein the crank angle to make the determination of removing the starter activation prohibition is updated after a determination of engine-stall by automatic stop.

9. A device for automatically stopping and restarting an internal combustion engine according to claim 7, wherein the crank angle to make the determination of removing the starter activation prohibition is updated when updating conditions are met multiple times.

10. A device for automatically stopping and restarting an internal combustion engine according to claim 3, wherein the predetermined tolerable rotation speed is obtained from a factor deciding a contacting time for the pinion gear to contact the ring gear after the activation of the starter is started.

11. A device for automatically stopping and restarting an internal combustion engine according to claim 2, wherein the crank angle sensor is a sensor capable of detecting the engine reverse rotation.

12. A device for automatically stopping and restarting an internal combustion engine according to claim 3, wherein the crank angle sensor is a sensor capable of detecting the engine reverse rotation.

13. A device for automatically stopping and restarting an internal combustion engine according to claim 8, wherein the crank angle to make the determination of removing the starter activation prohibition is updated when updating conditions are met multiple times.