Automatic stopping and restarting device of internal combustion engine

• US 9,624,894 B2
• Filed: 05/15/2013
• Issued: 04/18/2017
• Est. Priority Date: 05/15/2013
• Status: Active Grant

• Current Assignee: Mitsubishi Electric Corporation
• Original Assignee: Mitsubishi Electric Corporation
• Inventors: Shoda, Tomohisa, Ishikawa, Osamu, Okabe, Takeru, Kitano, Hiroaki
• Primary Examiner(s): Rivera, Carlos A
• Assistant Examiner(s): Manley, Sherman
• Application Number:
  US14/758,271
• Publication Number:
  US 20150345457A1
• Time in Patent Office: 1,434 Days
• CPC Class Codes: F02D 17/04 rendering engines inoperative or idling, e.g. caused by abnormal conditions dependent on lubricating conditions F01M1/22; dependent on cooling F01P5/14
• CPC Class Codes: F02D 29/02 peculiar to engines driving vehicles; peculiar to engines driving variable pitch propellers
• CPC Class Codes: F02D 41/009 using means for generating position or synchronisation signals
• CPC Class Codes: F02D 41/0097 using means for generating speed signals
• CPC Class Codes: F02D 41/30 Controlling fuel injection F02D41/182, F02D41/24 take precedence
• CPC Class Codes: F02N 11/0833 Vehicle conditions F02N11/0822, F02N11/0825 take precedence
• 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 2200/022 Engine speed
• CPC Class Codes: F02N 99/004 Generation of the ignition spark
• CPC Class Codes: F02N 99/006 Providing a combustible mixture inside the cylinder
• CPC Class Codes: Y02T 10/40 Engine management systems

Abstract

In an automatically stopped internal combustion engine, a rotation speed at next and subsequent ignition timings is predicted at every ignition timing of the internal combustion engine after the internal combustion engine is stopped automatically. Whether self-restorable restarting is allowed is determined according to a comparison result of the predictive rotation speed and a self-restoration determination rotation speed, so that self-restorable restarting is performed in a reliable manner.

Claims

1. An automatic stopping and restarting device of an internal combustion engine configured to automatically stop the internal combustion engine when predetermined automatic stopping conditions are established while the internal combustion engine is running and to restart the internal combustion engine when predetermined restarting conditions are established while the internal combustion engine is in an automatically stopped period, the automatic stopping and restarting device being characterized by comprising:

a crank angle detection sensor to detect a crank angle of the internal combustion engine;

a rotation speed computation unit to compute a rotation speed of the internal combustion engine based on the crank angle;

a restart timing control unit to select a cylinder for restart fuel injection;

a fuel injection control unit to restart fuel injection to the selected cylinder after the restarting conditions are established;

an engine control unit configured to;

predict a rotation speed of the internal combustion engine at ignition timing after the internal combustion engine is instructed to automatically stop if restarting conditions are established;

to determine whether self-restoration of the internal combustion engine is allowed according to a comparison result of a predictive rotation speed of the internal combustion engine at the ignition timing and a pre-set self-restoration determination rotation speed; and

to instruct the fuel injection control unit to restart fuel injection if self-restoration is allowed.

2. The automatic stopping and restarting device of an internal combustion engine according to claim 1, wherein the predictive rotation speed of the internal combustion engine at the ignition timing is an initial combustion rotation speed which is a rotation speed of the internal combustion engine at ignition timing at which initial combustion of fuel injected into a predetermined cylinder by the fuel injection control means according to timing when the restarting conditions are established takes place.

3. The automatic stopping and restarting device of an internal combustion engine according to claim 2, wherein the engine control unit computes the initial combustion rotation speed using a predictive rotation speed that takes a variation of rotation energy of the internal combustion engine into account.

4. The automatic stopping and restarting device of an internal combustion engine according to claim 3, wherein the engine control unit makes a first prediction of the predictive rotation speed using the rotation energy of the internal combustion engine after the internal combustion engine is automatically stopped as an initial value.

5. The automatic stopping and restarting device of an internal combustion engine according to claim 2, wherein the self-restoration determination rotation speed is determined on the basis of at least one of a water temperature, an intake pipe pressure, and a rotation load of the internal combustion engine.

6. The automatic stopping and restarting device of an internal combustion engine according to claim 2, wherein when the self-restoration allowance is determined that self-restoration is allowed and an increase amount of the rotation speed of the internal combustion engine from ignition timing of initial combustion is smaller than a pre-set self-restoration determination rotation speed correction necessity determination value, a necessity of a correction on the self-restoration determination rotation speed is determined and a predetermined correction coefficient is added to the self-restoration determination rotation speed.

7. The automatic stopping and restarting device of an internal combustion engine according to claim 6, wherein the self-restoration determination rotation speed correction necessity determination value is determined on the basis of at least one of a water temperature, an intake pipe pressure, and a rotation load of the internal combustion engine.