Knocking control system and method for internal combustion engine using multiple fuels

• US 6,951,202 B2
• Filed: 10/29/2004
• Issued: 10/04/2005
• Est. Priority Date: 11/26/2003
• Status: Expired due to Fees

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Oda, Tomihisa
• Primary Examiner(s): HUYNH, HAI H
• Application Number:
  US10/976,043
• Publication Number:
  US 20050109316A1
• Time in Patent Office: 340 Days
• Field of Search: 123/406.29, 123/299, 123/304, 123/305, 123/1.A, 701/103, 701/111
• US Class Current: 123/406.29
• 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 19/0636 by estimation, i.e. without using direct measurements of a corresponding sensor
• CPC Class Codes: F02D 19/0649 Liquid fuels having different boiling temperatures, volatilities, densities, viscosities, cetane or octane numbers
• CPC Class Codes: F02D 19/0665 Tanks, e.g. multiple tanks
• CPC Class Codes: F02D 19/0692 Arrangement of multiple injectors per combustion chamber
• CPC Class Codes: F02D 19/081 Adjusting the fuel composition or mixing ratio; Transitioning from one fuel to the other
• CPC Class Codes: F02D 35/027 using knock sensors
• 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: Y02T 10/30 Use of alternative fuels, e.g. biofuels

Abstract

High octane fuel and low octane fuel are supplied into the combustion chamber of an engine from high-octane fuel tank and low octane fuel tank via a high octane fuel injector and a low octane fuel injector. During a knocking control, if the quantity of high and low octane fuels in the respective tanks has been unbalanced, the supply ratio between high octane fuel and low octane fuel is changed 1 to control a knocking occurring in the engine without changing the ignition timing.

Claims

1. A knocking control system for an internal combustion engine, comprising:

a fuel supply mechanism capable of supplying the internal combustion engine with a first fuel and a second fuel with a different octane rating from the first fuel, and

a controller performing a knocking control to control a knocking occurring in the internal combustion engine, the controller being adapted to;

obtain a requested ignition timing during the knocking control;

obtain a remaining quantity of the first fuel and the second fuel; and

select and change one of an ignition timing and a fuel supply ratio between the first and second fuels, the selection being made based on the requested ignition timing and the remaining quantity of the first and second fuels.

2. A knocking control system according to claim 1, wherein

the controller is further adapted to change both the ignition timing and the supply ratio between the first and second fuels when a supply ratio of the first or second fuel is expected to exceed a predetermined ratio as a result of said fuel supply ratio being selected and changed.

3. A knocking control system according to claim 1, wherein

the octane rating of the first fuel is higher than the octane rating of the second fuel, and

the controller is further adapted to increase the supply ratio of the first fuel with an increase in a rate at which an accelerator opening is changed.

4. A knocking control system according to claim 2, wherein

the predetermined ratio is 100%.

5. A method for performing a knocking control to control a knocking occurring in an internal combustion engine running on a first fuel and a second fuel with a different octane rating from the first fuel, the method comprising:

obtaining a requested ignition timing during the knocking control;

obtaining a remaining quantity of the first fuel and the second fuel; and

selecting and changing one of an ignition timing and a fuel supply ratio between the first and second fuels, the selection being made based on the requested ignition timing and the remaining quantity of the first and second fuels.

6. A method according to claim 5, wherein

the ignition timing and the supply ratio between the first and second fuels are both changed when a supply ratio of the first or second fuel is expected to exceed a predetermined ratio as a result of said fuel supply ratio being selected and changed.

7. A method according to claim 5, wherein

the octane rating of the first fuel is higher than the octane rating of the second fuel, and

the supply ratio of the first fuel is increased with an increase in a rate at which an accelerator opening is changed.

8. A method according to claim 6, wherein

the predetermined ratio is 100%.

9. A knocking control system for an internal combustion engine, comprising:

fuel supply means for supplying the internal combustion engine with a first fuel and a second fuel with a different octane rating from the first fuel, and

controlling means for performing a knocking control to control a knocking occurring in the internal combustion engine, wherein

the control means;

obtains a requested ignition timing during the knocking control;

obtains a remaining quantity of the first fuel and the second fuel; and

selects and changes one of an ignition timing and a fuel supply ratio between the first and second fuels, the selection being made based on the requested ignition timing and the remaining quantity of the first and second fuels.