EMISSION DETERIORATION NOTIFYING DEVICE

• US 20120022740A1
• Filed: 07/14/2011
• Published: 01/26/2012
• Est. Priority Date: 07/23/2010
• Status: Active Grant

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: OHSAKI, Satoru
• Granted Patent: US 8,954,221 B2
• Time in Patent Office: Days
• US Class Current: 701/29
• CPC Class Codes: F02D 2041/228 Warning displays
• CPC Class Codes: F02D 2200/0602 Fuel pressure
• CPC Class Codes: F02D 2200/0802 Temperature of the exhaust gas treatment apparatus
• CPC Class Codes: F02D 41/0235 in relation with the state of the exhaust gas treating apparatus control of exhaust gas treating apparatus per se F01N
• CPC Class Codes: F02D 41/123 the fuel injection being cut-off
• CPC Class Codes: F02D 41/1446 the characteristics being exhaust temperatures
• CPC Class Codes: F02D 41/22 Safety or indicating devices for abnormal conditions in air/fuel ratio feedback systems F02D41/1495, in electric control linkage F02D11/107, in purge control systems F02M25/0809
• CPC Class Codes: F02D 41/2403 using essentially up/down counters
• CPC Class Codes: F02D 41/3035 a mode being the premixed charge compression-ignition mode

Abstract

An emission deterioration notifying device includes a low fuel pressure determining unit, an emission deterioration notifying unit, and an electric control unit. The determining unit determines whether supply pressure of fuel supplied to an injector is in a low fuel pressure state, in which the supply pressure is lower than a predetermined threshold value. The notifying unit notifies that exhaust emission is deteriorating beyond its allowable range when it is determined that the supply pressure is in the low fuel pressure state. The control unit allows notification by the notifying unit at a time of injection control at which injection of fuel from the injector is allowed, and the control unit prohibits notification by the notifying unit or reduces the threshold value at a time of injection stop control at which injection of fuel from the injector is stopped.

Claims

1. An emission deterioration notifying device adapted for a spark-ignition internal combustion engine including a combustion chamber and for a fuel injection system including an injector, the engine being a direct-injection internal combustion engine that injects fuel from the injector directly into the combustion chamber, the emission deterioration notifying device comprising:

a low fuel pressure determining means for determining whether supply pressure of fuel supplied to the injector is in a low fuel pressure state, in which the supply pressure is lower than a predetermined threshold value;

an emission deterioration notifying means for notifying that exhaust emission is deteriorating beyond its allowable range when it is determined that the supply pressure is in the low fuel pressure state; and

an electric control unit that is configured to allow the notification by the emission deterioration notifying means at a time of injection control at which the injection of fuel from the injector is allowed, and that is configured to prohibit the notification by the emission deterioration notifying means or to reduce the threshold value at a time of injection stop control at which the injection of fuel from the injector is stopped.

2. The emission deterioration notifying device according to claim 1, further comprising:

an abnormality determination means for determining whether the supply pressure of fuel supplied to the injector is in a fuel pressure abnormal condition, in which the supply pressure is lower than a predetermined lower limit; and

a diagnostic signal outputting means for outputting a diagnostic signal, which indicates that there is an abnormality in the fuel injection system, when it is determined that the supply pressure is in the fuel pressure abnormal condition, wherein the threshold value used in the determination by the low fuel pressure determining means is set at a different value from the lower limit, which is used in the determination by the abnormality determination means.

3. The emission deterioration notifying device according to claim 1, wherein:

the fuel injection system further includes a fuel pump that pressure-feeds fuel to the injector;

the fuel injection system controls operation of the fuel pump such that the supply pressure of fuel pressure-fed by the fuel pump to the injector reaches a target pressure; and

the threshold value is variably set according to actual pressure of fuel supplied to the injector or the target pressure.

4. An emission deterioration notifying device adapted for a spark-ignition internal combustion engine including a combustion chamber and a catalyst device that purifies exhaust gas and for a fuel injection system including an injector, the engine being a direct-injection internal combustion engine that injects fuel from the injector directly into the combustion chamber, the emission deterioration notifying device comprising:

a low fuel pressure determining means for determining whether supply pressure of fuel supplied to the injector is in a low fuel pressure state, in which the supply pressure is lower than a predetermined threshold value;

an emission deterioration notifying means for notifying that exhaust emission is deteriorating beyond its allowable range when it is determined that the supply pressure is in the low fuel pressure state; and

an electric control unit that is configured to allow the notification by the emission deterioration notifying means at a time of deactivation at which the catalyst device has not reached a catalytic activation temperature, and that is configured to prohibit the notification by the emission deterioration notifying means or to reduce the threshold value at a time of activation at which the catalyst device has the catalytic activation temperature or higher.

5. The emission deterioration notifying device according to claim 4, further comprising:

an abnormality determination means for determining whether the supply pressure of fuel supplied to the injector is in a fuel pressure abnormal condition, in which the supply pressure is lower than a predetermined lower limit; and

a diagnostic signal outputting means for outputting a diagnostic signal, which indicates that there is an abnormality in the fuel injection system, when it is determined that the supply pressure is in the fuel pressure abnormal condition, wherein the threshold value used in the determination by the low fuel pressure determining means is set at a different value from the lower limit, which is used in the determination by the abnormality determination means.

6. The emission deterioration notifying device according to claim 4, wherein:

the fuel injection system further includes a fuel pump that pressure-feeds fuel to the injector;

the fuel injection system controls operation of the fuel pump such that the supply pressure of fuel pressure-fed by the fuel pump to the injector reaches a target pressure; and

the threshold value is variably set according to actual pressure of fuel supplied to the injector or the target pressure.

7. An emission deterioration notifying device adapted for a spark-ignition internal combustion engine including a combustion chamber and for a fuel injection system including an injector, the engine being a direct-injection internal combustion engine that injects fuel from the injector directly into the combustion chamber, the emission deterioration notifying device comprising:

a low fuel pressure determining means for determining whether supply pressure of fuel supplied to the injector is in a low fuel pressure state, in which the supply pressure is lower than a predetermined threshold value;

an emission deterioration notifying means for notifying that exhaust emission is deteriorating beyond its allowable range when it is determined that the supply pressure is in the low fuel pressure state; and

an electric control unit that is configured to allow the notification by the emission deterioration notifying means when the engine is in a low temperature state in which temperature of the engine has not reached a predetermined temperature, and that is configured to prohibit the notification by the emission deterioration notifying means or to reduce the threshold value when the engine is in a high temperature state in which the temperature of the engine is equal to or higher than the predetermined temperature.

8. The emission deterioration notifying device according to claim 7, further comprising:

an abnormality determination means for determining whether the supply pressure of fuel supplied to the injector is in a fuel pressure abnormal condition, in which the supply pressure is lower than a predetermined lower limit; and

a diagnostic signal outputting means for outputting a diagnostic signal, which indicates that there is an abnormality in the fuel injection system, when it is determined that the supply pressure is in the fuel pressure abnormal condition, wherein the threshold value used in the determination by the low fuel pressure determining means is set at a different value from the lower limit, which is used in the determination by the abnormality determination means.

9. The emission deterioration notifying device according to claim 7, wherein:

the fuel injection system further includes a fuel pump that pressure-feeds fuel to the injector;

the fuel injection system controls operation of the fuel pump such that the supply pressure of fuel pressure-fed by the fuel pump to the injector reaches a target pressure; and

the threshold value is variably set according to actual pressure of fuel supplied to the injector or the target pressure.

10. An emission deterioration notifying device adapted for a spark-ignition internal combustion engine including a combustion chamber and for a fuel injection system including an injector, the engine being a direct-injection internal combustion engine that injects fuel from the injector directly into the combustion chamber, the emission deterioration notifying device comprising:

an injection prohibition control means for prohibiting the injection of fuel from the injector in a period after starting of the engine is begun until supply pressure of fuel supplied to the injector rises to reach a predetermined threshold value;

a confirmation means for confirming whether fuel is erroneously injected in the period during which the injection of fuel is prohibited by the injection prohibition control means; and

an emission deterioration notifying means for notifying that exhaust emission is deteriorating beyond its allowable range when it is confirmed by the confirmation means that fuel is erroneously injected.

11. The emission deterioration notifying device according to claim 10, wherein:

the fuel injection system further includes;

an injection command means for outputting an injection command signal that is set in accordance with an operating state of the engine; and

a drive circuit that is configured to control drive electric power supplied to the injector based on the injection command signal; and

the confirmation means confirms whether fuel is erroneously injected based on the drive electric power controlled by the drive circuit.