Idling stop apparatus and method for disabling idling stop function

• US 8,887,684 B2
• Filed: 09/17/2010
• Issued: 11/18/2014
• Est. Priority Date: 09/25/2009
• Status: Active Grant

• Current Assignee: Fujitsu Ten Limited (DENSO Corporation)
• Original Assignee: Fujitsu Ten Limited (DENSO Corporation)
• Inventors: Izumoto, Ryoh, Komiya, Motoki, Shimizu, Yuichiro, Shibachi, Yoshinori
• Primary Examiner(s): Moulis, Thomas
• Assistant Examiner(s): DALLO, JOSEPH J
• Application Number:
  US13/498,022
• Publication Number:
  US 20120221229A1
• Time in Patent Office: 1,523 Days
• Field of Search: 123/179.3, 123/179.4, 123/198.DB, 701112-115, 307/10.1, 307/10.6, 307/10.7
• US Class Current: 123/179.4
• CPC Class Codes: F02D 29/02 peculiar to engines driving vehicles; peculiar to engines driving variable pitch propellers
• CPC Class Codes: F02N 11/0825 related to prevention of engine restart failure, e.g. disabling automatic stop at low battery state
• CPC Class Codes: F02N 11/0862 characterised by the electrical power supply means, e.g. battery
• CPC Class Codes: F02N 2250/02 Battery voltage drop at start, e.g. drops causing ECU reset
• CPC Class Codes: F02N 2300/30 characterised by the use of digital means
• CPC Class Codes: Y02T 10/40 Engine management systems

Abstract

An idling stop apparatus is provided which can prevent a voltage of a battery from being lowered even when a microcomputer is reset. In an idling stop apparatus when a reset condition is established, reset information indicating that the reset condition is established is stored in a latch circuit and a microcomputer disables an idling stop function when the reset information is stored. The reset information is stored in the latch circuit even when the microcomputer is being reset or even after the microcomputer is reset. Accordingly, the microcomputer after the reset can disable the idling stop function. As a result, it is possible to prevent the voltage of the battery from being lowered due to the idling stop function.

Claims

1. An idling stop apparatus to be mounted on a vehicle, comprising:

a microcomputer, having an idling stop function of automatically stopping an engine of the vehicle when a predetermined stop condition is established and of automatically starting the engine when a predetermined start condition is established while the engine is stopped;

a detector, that detects that a power-supply voltage of the microcomputer is below a first voltage, the first voltage being a minimum operating voltage of the microcomputer; and

a flip-flop, that stores reset information when the detector detects that the power-supply voltage of the microcomputer is below the first voltage, and outputs a signal for prohibiting the microcomputer from executing the idling stop function while the flip-flop is storing the reset information,

wherein the first voltage is higher than a second voltage, the second voltage being a minimum operating voltage of the flip-flop, and

when, after the flip-flop stops operating, the flip-flop starts operating again upon starting of the engine, the flip-flop stores the reset information again when the detector detects that the power-supply voltage of the microcomputer is below the first voltage.

3. The idling stop apparatus according to claim 1,

wherein the flip-flop deletes the reset information when an ignition switch of the vehicle is turned off, and

wherein the second voltage is higher than a reference voltage which is used for detecting that the ignition switch is turned on.

4. The idling stop apparatus according to claim 1, wherein the power-supply voltage of the microcomputer is obtained by decreasing a voltage of a battery of the vehicle.

2. A method for disabling an idling stop function of automatically stopping an engine of a vehicle when a predetermined stop condition is established and of automatically starting the engine when a predetermined start condition is established during the engine is stopped, the method comprising:

detecting, by a detector, that a power-supply voltage of a microcomputer having the idling stop function is below a first voltage, the first voltage being a minimum operating voltage of the microcomputer;

storing, by a flip-flop, reset information when the detector detects that the power-supply voltage of the microcomputer is below the first voltage;

outputting, by the flip-flop, a signal for prohibiting the microcomputer from executing the idling stop function while the flip-flop is storing the reset information; and

when, after the flip-flop stops operating, the flip-flop starts operating again upon starting of the engine, storing, by the flip-flop, the reset information again when the detector detects that the power-supply voltage of the microcomputer is below the first voltage,

wherein the first voltage is higher than a second voltage, the second voltage being a minimum operating voltage of the flip-flop.

5. The method according to claim 2, further comprising deleting, by the flip-flop, the reset information when an ignition switch of the vehicle is turned off,

wherein the second voltage is higher than a reference voltage which is used for detecting that the ignition switch is turned on.

6. The method according to claim 2, wherein the power-supply voltage of the microcomputer is obtained by decreasing a voltage of a battery of the vehicle.