Fuel property determination system, and fuel property determination method for internal combustion engine

• US 7,778,763 B2
• Filed: 06/12/2007
• Issued: 08/17/2010
• Est. Priority Date: 06/13/2006
• Status: Expired due to Fees

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Ueda, Koichi, Sata, Kota
• Primary Examiner(s): Cronin; Stephen K
• Assistant Examiner(s): Hoang; Johnny H
• Application Number:
  US12/304,428
• Publication Number:
  US 20090287396A1
• Time in Patent Office: 1,162 Days
• Field of Search: 701101-105, 701110-115, 123/179.16, 123/436, 123478-480, 123/491, 123/494, 731/141.3, 731/141.5, 731/144.2, 731/144.5, 731/144.9, 731/145.2, 702/182
• US Class Current: 701/104
• CPC Class Codes: F02D 19/061 by controlling fuel injectors
• CPC Class Codes: F02D 19/0636 by estimation, i.e. without using direct measurements of a corresponding sensor
• CPC Class Codes: F02D 19/0657 Heavy or light fuel oils; Fuels characterised by their impurities such as sulfur content or differences in grade, e.g. for ships
• CPC Class Codes: F02D 2200/0612 determined by estimation
• CPC Class Codes: F02D 2200/1004 Estimation of the output torque
• 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 41/062 for starting F02D41/061 takes precedence
• CPC Class Codes: F02D 41/1497 With detection of the mechanical response of the engine
• CPC Class Codes: Y02T 10/30 Use of alternative fuels, e.g. biofuels

Abstract

The fuel injection amounts into each cylinder are set on the assumption that a heavy fuel will be injected during the engine starting process, and a specific torque is allowed to be generated by combustion in a specific cylinder when a fuel with a specific property between those of the heaviest fuel and the lightest fuel is injected thereinto. When the torque generated in the specific cylinder is in a range at or around the specific torque, the property level of fuel to be injected during the engine starting process is determined to be in a level range at or around the specific property. When the torque generated in the specific cylinder is higher than the range around the specific torque, the property level is determined to be in a level range on the light fuel side of the level range around the specific property.

Claims

1. A fuel property determination system for a multi-cylinder internal combustion engine that sets fuel injection amounts into each of the cylinders during the engine starting process on the assumption that a heavy fuel will be injected, wherein the fuel property determination system

allows a specific torque to be generated by combustion in a specific cylinder when a fuel with a specific property between those of the heaviest fuel and the lightest fuel is injected thereinto,

determines that the property level of fuel to be injected into each cylinder during the engine starting process is in a level range at and around the specific property when the torque actually generated in the specific cylinder is in a range at and around the specific torque,

determines that the property level is in a level range on the light fuel side of the level range at and around the specific property when the torque actually generated in the specific cylinder is higher than the range at and around the specific torque,

determines that the property level is in a level range on the heavy fuel side of the level range at and around the specific property when the torque actually generated in the specific cylinder is lower than the range at and around the specific torque,

decreases a fuel injection amount so that the specific torque is generated by combustion in the specific cylinder when the fuel with a specific property is injected thereinto,

allows a specific torque to be generated by combustion in at least a second specific cylinder when the fuel with a specific property is injected thereinto without decreasing the fuel injection amount thereinto,

determines that the property level of fuel to be injected into each cylinder during the engine starting process is in a level range at or around the specific property when the torque actually generated in the second specific cylinder is in a range at or around the specific torque,

determines that the property level is in a level range on the light fuel side of the level range at or around the specific property when the torque actually generated in the second specific cylinder is higher than the range at or around the specific torque,

determines that the property level is in a level range on the heavy fuel side of the level range at or around the specific property when the torque actually generated in the second specific cylinder is lower than the range at or around the specific torque, and

determines, only when the fuel property level determined in the specific cylinder and the fuel property level determined in the second specific cylinder coincide with each other the coincident fuel property level as the property level of the fuel to be injected into each cylinder during the engine starting process.

3. The fuel property determination system for an internal combustion engine according to claim 1, wherein

the fuel property determination system starts correction of the fuel injection amounts during the engine starting process, based on the fuel property level determined, immediately after the determination.

2. A fuel property determination system for a multi-cylinder internal combustion engine that sets fuel injection amounts into each of the cylinders during the engine starting process on the assumption that a heavy fuel will be injected, wherein

the fuel property determination system

allows a specific torque to be generated by combustion in a specific cylinder when a fuel with a specific property between those of the heaviest fuel and the lightest fuel is injected thereinto,

determines that the property level of fuel to be injected into each cylinder during the engine starting process is in a level range at and around the specific property when the torque actually generated in the specific cylinder is in a range at and around the specific torque,

determines that the property level is in a level range on the light fuel side of the level range at and around the specific property when the torque actually generated in the specific cylinder is higher than the range at and around the specific torque,

determines that the property level is in a level range on the heavy fuel side of the level range at and around the specific property when the torque actually generated in the specific cylinder is lower than the range at and around the specific torque,

allows a specific torque to be generated by combustion in at least a second specific cylinder in which combustion occurs after combustion in the specific cylinder when the fuel with a specific property is injected thereinto,

determines that the property level of fuel to be injected into each cylinder during the engine starting process is in a level range at or around the specific property when the torque actually generated in the second specific cylinder is in a range at or around the specific torque,

determines that the property level is in a level range on the light fuel side of the level range at or around the specific property when the torque actually generated in the second specific cylinder is higher than the range at or around the specific torque,

determines that the property level is in a level range on the heavy fuel side of the level range at or around the specific property when the torque actually generated in the second specific cylinder is lower than the range at or around the specific torque, and

determines a weighted average of the fuel property level determined in the specific cylinder and the fuel property level determined in the second specific cylinder obtained by giving a higher weight to the former than to the latter as the property level of fuel to be injected into each cylinder during the engine starting process.

4. A fuel property determination method for a multi-cylinder internal combustion engine, comprising:

setting fuel injection amounts into each of the cylinders during the engine starting process on the assumption that a heavy fuel will be injected;

allowing a specific torque to be generated by combustion in a specific cylinder when a fuel with a specific property between those of the heaviest fuel and the lightest fuel is injected thereinto;

determining that the property level of fuel to be injected into each cylinder during the engine starting process is in a level range at or around the specific property when the torque actually generated in the specific cylinder is in a range at or around the specific torque;

determining that the property level is in a level range on the light fuel side of the level range at or around the specific property when the torque actually generated in the specific cylinder is higher than the range at or around the specific torque; and

determining that the property level is in a level range on the heavy fuel side of the level range at or around the specific property when the torque actually generated in the specific cylinder is lower than the range at or around the specific torque,

decreasing a fuel injection amount so that the specific torque is generated by combustion in the specific cylinder when the fuel with the specific property is injected thereinto;

allowing a specific torque to be generated by combustion in at least a second specific cylinder when the fuel with a specific property is injected thereinto without decreasing the fuel injection amount thereinto;

determining that the property level of fuel to be injected into each cylinder during the engine starting process is in a level range at or around the specific property when the torque actually generated in the second specific cylinder is in a range at or around the specific torque;

determining that the property level is in a level range on the light fuel side of the level range at or around the specific property when the torque actually generated in the second specific cylinder is higher than the range at or around the specific torque;

determining that the property level is in a level range on the heavy fuel side of the level range at or around the specific property when the torque actually generated in the second specific cylinder is lower than the range at or around the specific torque; and

determining, only when the fuel property level determined in the specific cylinder and the fuel property level determined in the second specific cylinder coincide with each other, the coincident fuel property level as the property level of the fuel to be injected into each cylinder during the engine starting process.

5. The fuel property determination method for an internal combustion engine according to claim 4, further comprising:

starting correction of the fuel injection amounts during the engine starting process, based on the fuel property level determined, immediately after the determination.

6. A fuel property determination method for a multi-cylinder internal combustion engine, comprising:

setting fuel injection amounts into each of the cylinders during the engine starting process on the assumption that a heavy fuel will be injected;

allowing a specific torque to be generated by combustion in a specific cylinder when a fuel with a specific property between those of the heaviest fuel and the lightest fuel is injected thereinto;

determining that the property level of fuel to be injected into each cylinder during the engine starting process is in a level range at or around the specific property when the torque actually generated in the specific cylinder is in a range at or around the specific torque;

determining that the property level is in a level range on the light fuel side of the level range at or around the specific property when the torque actually generated in the specific cylinder is higher than the range at or around the specific torque;

determining that the property level is in a level range on the heavy fuel side of the level range at or around the specific property when the torque actually generated in the specific cylinder is lower than the range at or around the specific torque,

allowing a specific torque to be generated by combustion in at least a second specific cylinder in which combustion occurs after combustion in the specific cylinder when the fuel with a specific property is injected thereinto;

determining that the property level of fuel to be injected into each cylinder during the engine starting process is in a level range at or around the specific property when the torque actually generated in the second specific cylinder is in a range at or around the specific torque;

determining that the property level is in a level range on the light fuel side of the level range at or around the specific property when the torque actually generated in the second specific cylinder is higher than the range at or around the specific torque;

determining that the property level is in a level range on the heavy fuel side of the level range at or around the specific property when the torque actually generated in the second specific cylinder is lower than the range at or around the specific torque; and

determining a weighted average of the fuel property level determined in the specific cylinder and the fuel property level determined in the second specific cylinder obtained by giving a higher weight to the former than to the latter as the property level of fuel to be injected into each cylinder during the engine starting process.