ENGINE AUTOMATIC STOP-START CONTROLLER

• US 20100042311A1
• Filed: 08/03/2009
• Published: 02/18/2010
• Est. Priority Date: 08/08/2008
• Status: Active Grant

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: NAKAI, Yasuhiro
• Granted Patent: US 7,848,875 B2
• Time in Patent Office: Days
• US Class Current: 701/112
• CPC Class Codes: F02D 2041/1433 using a model or simulation of the system
• CPC Class Codes: F02D 2200/1012 Engine speed gradient
• CPC Class Codes: F02D 2200/1015 Engines misfires
• CPC Class Codes: F02D 41/009 using means for generating position or synchronisation signals
• CPC Class Codes: F02D 41/062 for starting F02D41/061 takes precedence
• 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 11/103 according to the vehicle transmission or clutch status
• CPC Class Codes: F02N 19/005 Aiding engine start by starting from a predetermined position, e.g. pre-positioning or reverse rotation
• CPC Class Codes: F02N 2019/008 the engine being stopped in a particular position
• CPC Class Codes: F02N 2200/021 Engine crank angle
• CPC Class Codes: F02N 2200/022 Engine speed
• CPC Class Codes: F02N 2300/102 Control of the starter motor speed; Control of the engine speed during cranking
• CPC Class Codes: Y02T 10/40 Engine management systems

Abstract

A first ignition cylinder that performs ignition first is set based on an engine stop position in automatic start. Existence/nonexistence of a misfire in the first ignition cylinder is determined based on whether a difference ΔNe between engine rotation speed at a predetermined crank angle in an interval from timing immediately before the ignition to timing immediately after the ignition of the first ignition cylinder (e.g., at TDC of first ignition cylinder) and engine rotation speed at a predetermined crank angle before ignition of a second ignition cylinder (e.g., at TDC of second ignition cylinder) is equal to or smaller than a predetermined misfire determination threshold value Nef. When misfire time number of the first ignition cylinder exceeds a predetermined value, fuel supply to the first ignition cylinder is prohibited and the automatic start is started from the second ignition cylinder.

Claims

1. An engine automatic stop-start controller that automatically stops an engine when a predetermined automatic stop condition is established and then automatically starts the engine when a predetermined automatic start condition is established, the engine automatic stop-start controller comprising:

a first ignition cylinder setting means for setting a first ignition cylinder that performs ignition first based on an engine stop position in the automatic start; and

a misfire determination means for determining existence or nonexistence of a misfire in the first ignition cylinder based on whether a difference between engine rotation speed at a predetermined crank angle in an interval from timing immediately before the ignition to timing immediately after the ignition of the first ignition cylinder and engine rotation speed at a predetermined crank angle before ignition of a second ignition cylinder is equal to or lower than a predetermined misfire determination threshold value.

2. The engine automatic stop-start controller as in claim 1, further comprising:

an automatic start control means for prohibiting fuel supply to the first ignition cylinder and for starting the automatic start from the second ignition cylinder when misfire time number or misfire frequency of the first ignition cylinder sensed by the misfire determination means exceeds a predetermined value.

3. The engine automatic stop-start controller as in claim 2, wherein

the misfire determination means counts the misfire time number or the misfire frequency at the time when each cylinder is the first ignition cylinder for each cylinder and stores the misfire time number or the misfire frequency in a memory for each cylinder.

4. An engine automatic stop-start controller that automatically stops an engine when a predetermined automatic stop condition is established and then automatically starts the engine when a predetermined automatic start condition is established, the engine automatic stop-start controller comprising:

a first ignition cylinder setting means for setting a first ignition cylinder that performs ignition first based on an engine stop position in the automatic start; and

a misfire determination means for determining existence or nonexistence of a misfire in the first ignition cylinder based on whether engine rotation speed at a predetermined crank angle after the ignition of the first ignition cylinder and before ignition of a second ignition cylinder is equal to or lower than a predetermined misfire determination threshold value.

5. The engine automatic stop-start controller as in claim 4, further comprising:

an automatic start control means for prohibiting fuel supply to the first ignition cylinder and for starting the automatic start from the second ignition cylinder when misfire time number or misfire frequency of the first ignition cylinder sensed by the misfire determination means exceeds a predetermined value.

6. The engine automatic stop-start controller as in claim 5, wherein

the misfire determination means counts the misfire time number or the misfire frequency at the time when each cylinder is the first ignition cylinder for each cylinder and stores the misfire time number or the misfire frequency in a memory for each cylinder.