CONTROLLER FOR INTERNAL COMBUSTION ENGINE

• US 20100010726A1
• Filed: 06/17/2009
• Published: 01/14/2010
• Est. Priority Date: 07/11/2008
• Status: Active Grant

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: ORIKABE, Kentaro
• Granted Patent: US 7,909,020 B2
• Time in Patent Office: Days
• US Class Current: 701/103
• CPC Class Codes: F02D 19/0605 to adjust the fuel pressure or temperature
• CPC Class Codes: F02D 19/061 by controlling fuel injectors
• CPC Class Codes: F02D 19/0623 Failure diagnosis or prevention; Safety measures; Testing
• CPC Class Codes: F02D 19/0628 Determining the fuel pressure, temperature or flow, the fuel tank fill level or a valve position
• CPC Class Codes: F02D 19/0678 Pressure or flow regulators therefor; Fuel metering valves therefor
• CPC Class Codes: F02D 19/084 Blends of gasoline and alcohols, e.g. E85
• CPC Class Codes: F02D 19/087 with determination of densities, viscosities, composition, concentration or mixture ratios of fuels
• CPC Class Codes: F02D 2041/224 Diagnosis of the fuel system
• CPC Class Codes: F02D 2041/226 Fail safe control for fuel injection pump
• CPC Class Codes: F02D 2200/0611 Fuel type, fuel composition or fuel quality
• CPC Class Codes: F02D 41/0025 Controlling engines characterised by use of non-liquid fuels, pluralities of fuels, or non-fuel substances added to the combustible mixtures
• CPC Class Codes: F02D 41/221 relating to the failure of actuators or electrically driven elements
• CPC Class Codes: F02D 41/3005 Details not otherwise provided for
• CPC Class Codes: Y02T 10/30 Use of alternative fuels, e.g. biofuels

Abstract

At least one of a petroleum fuel and an alcohol fuel stored in a fuel tank is supplied to an internal combustion engine. Specifically, the fuel in the fuel tank is supplied to an injector by a fuel pump module. The injector injects the fuel into an intake pipe. An ECU adjusts a fuel injection quantity according to an alcohol concentration of the fuel When the fuel-supply-pressure to the injector is less than or equal to a threshold pressure, the ECU determines the fuel pump module has a malfunction. Especially, the ECU varies the threshold pressure according to the alcohol concentration of the fuel.

Claims

1. A controller for an internal combustion engine applied to a fuel supply system in which at least one of a petroleum fuel and an alcohol fuel stored in a fuel tank is supplied to an internal combustion engine, the fuel supply system including a pump device pumping the fuel stored in the fuel tank and an injector injecting the fuel pumped by the pump device into the internal combustion engine, the injector injecting the fuel of which quantity is varied according to an alcohol concentration of the fuel, the controller detecting a fuel pressure supplied to the injector and detecting a malfunction of the pump device when the fuel pressure is less than or equal to a threshold pressure, the controller comprising

an alcohol concentration detecting means for detecting an alcohol concentration of the fuel supplied to the internal combustion engine;

and

a threshold pressure setting means for setting the threshold pressure lower as the alcohol concentration detected by the alcohol concentration detecting means is higher.

2. A controller controlling the fuel pressure supplied to the injector to a target pressure according to claim 1, further comprising:

a target pressure setting means for setting the target pressure according to a driving condition of the internal combustion engine, wherein

the threshold pressure setting means sets the threshold pressure based on at least one of the driving condition of the internal combustion engine and the target pressure set by the target pressure setting means.

3. A controller determining whether a condition in which the fuel pressure supplied to the injector is less than or equal to the threshold pressure continues for a abnormality determination period or more, and detecting a malfunction of the pump device based on a determination result according to claim 1, further comprising:

a determination period setting means for setting the abnormality determination period longer as the alcohol concentration detected by the alcohol concentration detecting means is higher.

5. A controller controlling the fuel pressure supplied to the injector to a target pressure according to claim 3, further comprising:

a target pressure setting means for setting the target pressure of the fuel supplied to the injector according to a driving condition of the internal combustion engine, wherein

the determination period setting means sets the abnormality determination period based on at least one of the driving condition of the internal combustion engine and the target pressure set by the target pressure setting means

4. A controller for an internal combustion engine applied to a fuel supply system in which at least one of a petroleum fuel and an alcohol fuel stored in a fuel tank is supplied to an internal combustion engine, the fuel supply system including a pump device pumping the fuel stored in the fuel tank and an injector injecting the fuel pumped by the pump device into the internal combustion engine, a controller controlling a fuel injection quantity, determining whether a condition in which the fuel pressure supplied to the injector is less than or equal to the threshold pressure continues for a abnormality determination period or more, and detecting a malfunction of the pump device based on a determination result, the controller comprising:

an alcohol concentration detecting means for detecting an alcohol concentration of the fuel supplied to the internal combustion engine; and

a determination period setting means for setting the abnormality determination period longer as the alcohol concentration detected by the alcohol concentration detecting means is higher.