Multifuel internal combustion engine and combustion controlling method thereof

• US 7,853,396 B2
• Filed: 06/12/2007
• Issued: 12/14/2010
• Est. Priority Date: 09/28/2006
• Status: Active Grant

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Tanno, Shiro, Ito, Yasushi
• Primary Examiner(s): Cronin; Stephen K
• Assistant Examiner(s): Najmuddin; Raza
• Application Number:
  US12/442,668
• Publication Number:
  US 20100010725A1
• Time in Patent Office: 1,281 Days
• Field of Search: 123/295, 123/406.3, 123/406.31, 123/526, 123/527, 123/1.A, 123/299, 123/300, 123/304, 123/305, 123/575, 123/27.GE, 123/430, 123/431, 123/674, 123/698, 123/480, 123/515, 123/577, 123/578, 701/111, 701/101, 701/102, 701/103, 701/104, 701/105, 701/106, 701/115
• US Class Current: 701/103
• CPC Class Codes: F02B 11/00 Engines characterised by both fuel-air mixture compression and air compression, or characterised by both positive ignition and compression ignition, e.g. in different cylinders
• 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 19/0676 Multi-way valves; Switch-over valves
• CPC Class Codes: F02D 19/0689 for in-cylinder direct injection
• CPC Class Codes: F02D 19/0692 Arrangement of multiple injectors per combustion chamber
• CPC Class Codes: F02D 19/0694 operating with a plurality of fuels
• CPC Class Codes: F02D 19/081 Adjusting the fuel composition or mixing ratio; Transitioning from one fuel to the other
• CPC Class Codes: F02D 2200/0612 determined by estimation
• CPC Class Codes: F02D 35/02 on interior conditions
• CPC Class Codes: F02D 35/023 by determining the cylinder pressure
• CPC Class Codes: F02D 35/027 using knock sensors
• CPC Class Codes: F02D 35/028 by determining the combustion timing or phasing
• CPC Class Codes: F02D 41/0027 the fuel being gaseous non-electrical control F02D19/02
• CPC Class Codes: F02D 41/3017 characterised by the mode(s) being used
• CPC Class Codes: F02D 41/3076 with special conditions for selecting a mode of combustion, e.g. for starting, for diagnosing
• CPC Class Codes: F02D 41/345 Controlling injection timing F02D41/365 takes precedence
• CPC Class Codes: F02P 5/1527 with means allowing burning of two or more fuels, e.g. super or normal, premium or regular
• CPC Class Codes: Y02T 10/12 Improving ICE efficiencies
• CPC Class Codes: Y02T 10/30 : Use of alternative fuels, e.g. biofuels
• CPC Class Codes: Y02T 10/40 : Engine management systems

Abstract

A multifuel internal combustion engine includes: fuel characteristics determining unit that determines ignitability and anti-knocking performance of the fuel introduced into the combustion chamber CC; combustion mode setting unit that sets a compression hypergolic diffusion combustion mode when ignitability of the fuel is excellent, sets a premixed spark-ignition flame propagation combustion mode when the ignitability of the fuel is poor and anti-knocking performance is excellent, and sets a spark assist compression hypergolic diffusion combustion mode when both the ignitability and anti-knocking performance of the fuel are poor; and combustion control execution unit that makes the engine to drive in a combustion mode which is set by the combustion mode setting unit.

Claims

1. A multifuel internal combustion engine which is driven mainly at a theoretical air fuel ratio by introducing at least one of at least two kinds fuel having different properties into a combustion chamber or by introducing mixed fuel including the at least two kinds of fuel into the combustion chamber, the multifuel internal combustion engine comprising:

fuel characteristics determining unit that determines ignitability and anti-knocking performance of the fuel introduced into the combustion chamber;

combustion mode setting unit that sets a compression hypergolic diffusion combustion mode when ignitability of the fuel introduced into the combustion chamber is excellent, sets a premixed spark-ignition flame propagation combustion mode when the ignitability of the fuel introduced into the combustion chamber is poor and anti-knocking performance is excellent, and sets a spark assist compression hypergolic diffusion combustion mode when both the ignitability and anti-knocking performance of the fuel introduced into the combustion chamber are poor; and

combustion control execution unit that makes the engine to drive in a combustion mode which is set by the combustion mode setting unit.

2. The multifuel internal combustion engine according to claim 1, wherein the fuel characteristics determining unit further determines evaporativity or PM/smoke generating characteristics of the fuel introduced into the combustion chamber, and the combustion mode setting unit does not select the compression hypergolic diffusion combustion mode when the fuel introduced into the combustion chamber has poor evaporativity or the fuel easily generates PM or smoke.

3. The multifuel internal combustion engine according to claim 1, wherein when the fuel introduced into the combustion chamber has fuel characteristics that permit setting a plurality of kinds of combustion modes, the combustion mode setting unit selects a combustion mode which is excellent in both or any one of fuel consumption performance and emission control performance.

4. The multifuel internal combustion engine according to claim 2, wherein when the fuel introduced into the combustion chamber has fuel characteristics that permit setting a plurality of kinds of combustion modes, the combustion mode setting unit selects a combustion mode which is excellent in both or any one of fuel consumption performance and emission control performance.

5. The multifuel internal combustion engine according to claim 3, wherein when an improving margin of the fuel consumption performance and emission control performance caused by changing from the current combustion mode exceed a predetermined degree, the combustion mode setting unit executes changing of the combustion mode.

6. The multifuel internal combustion engine according to claim 4, wherein when an improving margin of the fuel consumption performance and emission control performance caused by changing from the current combustion mode exceed a predetermined degree, the combustion mode setting unit executes changing of the combustion mode.

7. The multifuel internal combustion engine according to claim 1, wherein at least one of at least two kinds fuel having different properties, or mixed fuel including the at least two kinds of fuel is introduced into the combustion chamber and an intake port.

8. A combustion controlling method of a multifuel internal combustion engine which is driven mainly at a theoretical air fuel ratio by introducing at least one of at least two kinds fuel having different properties into a combustion chamber or by introducing mixed fuel including the at least two kinds of fuel into the combustion chamber, the combustion controlling method comprising:

determining fuel characteristics with respect to ignitability and anti-knocking performance of the fuel introduced into the combustion chamber;

setting a compression hypergolic diffusion combustion mode when ignitability of the fuel introduced into the combustion chamber is excellent, setting a premixed spark-ignition flame propagation combustion mode when the ignitability of the fuel introduced into the combustion chamber is poor and anti-knocking performance is excellent, and setting a spark assist compression hypergolic diffusion combustion mode when both the ignitability and anti-knocking performance of the fuel introduced into the combustion chamber are poor; and

executing combustion control to make the engine to drive in a combustion mode which is set in the combustion mode setting.

9. The combustion controlling method of the multifuel internal combustion engine according to claim 8, wherein the fuel characteristics determining further determines evaporativity or PM/smoke generating characteristics of the fuel introduced into the combustion chamber, and the combustion mode setting does not select the compression hypergolic diffusion combustion mode when the fuel introduced into the combustion chamber has poor evaporativity or the fuel easily generates PM or smoke.

10. The combustion controlling method of the multifuel internal combustion engine according to claim 8, wherein when the fuel introduced into the combustion chamber has fuel characteristics that permit setting a plurality of kinds of combustion modes, the combustion mode setting selects a combustion mode which is excellent in both or any one of fuel consumption performance and emission control performance.

11. The combustion controlling method of the multifuel internal combustion engine according to claim 9, wherein when the fuel introduced into the combustion chamber has fuel characteristics that permit setting a plurality of kinds of combustion modes, the combustion mode setting selects a combustion mode which is excellent in both or any one of fuel consumption performance and emission control performance.

12. The combustion controlling method of the multifuel internal combustion engine according to claim 10, wherein when an improving margin of the fuel consumption performance and emission control performance caused by changing from the current combustion mode exceed a predetermined degree, the combustion mode setting executes changing of the combustion mode.

13. The combustion controlling method of the multifuel internal combustion engine according to claim 11, wherein when an improving margin of the fuel consumption performance and emission control performance caused by changing from the current combustion mode exceed a predetermined degree, the combustion mode setting executes changing of the combustion mode.

14. The combustion controlling method of the multifuel internal combustion engine according to claim 8, wherein at least one of at least two kinds fuel having different properties, or mixed fuel including the at least two kinds of fuel is introduced into the combustion chamber and an intake port.