Fuel switching for dual fuel engine

• US 7,228,841 B2
• Filed: 11/07/2005
• Issued: 06/12/2007
• Est. Priority Date: 11/12/2004
• Status: Expired due to Fees

• Current Assignee: Mazda Motor Corporation
• Original Assignee: Mazda Motor Corporation
• Inventors: Seo, Nobuhide, Kawada, Takuji, Douzono, Kazuho, Takemoto, Akira
• Primary Examiner(s): Cronin; Stephen K.
• Assistant Examiner(s): Hoang; Johnny H.
• Application Number:
  US11/268,331
• Publication Number:
  US 20060101823A1
• Time in Patent Office: 582 Days
• Field of Search: 123/1.A, 123/27.GE, 123/304, 123/575, 123/576, 123/577, 123/578, 123/525, 123/527, 607/06, 180/65.2, 180/65.4
• US Class Current: 123/304
• CPC Class Codes: B60K 6/24 characterised by the combustion engines
• CPC Class Codes: B60K 6/365 with the gears having orbital motion
• CPC Class Codes: B60K 6/445 Differential gearing distribution type
• CPC Class Codes: B60W 10/06 including control of combustion engines
• CPC Class Codes: B60W 10/08 including control of electric propulsion units, e.g. motors or generators
• CPC Class Codes: B60W 20/00 Control systems specially adapted for hybrid vehicles hybrid vehicle design, B60K6/00; electric vehicles B60L
• CPC Class Codes: B60W 20/10 Controlling the power contribution of each of the prime movers to meet required power demand
• CPC Class Codes: B60W 2710/0616 Position of fuel or air injector
• CPC Class Codes: B60W 2710/0644 Engine speed
• CPC Class Codes: F02D 19/0615 being initiated by automatic means, e.g. based on engine or vehicle operating conditions
• CPC Class Codes: F02D 19/0618 depending on the engine's or vehicle's position, e.g. on/off road or proximity to a harbor
• CPC Class Codes: F02D 19/0623 Failure diagnosis or prevention; Safety measures; Testing
• CPC Class Codes: F02D 19/0644 the gaseous fuel being hydrogen, ammonia or carbon monoxide
• CPC Class Codes: F02D 19/0692 Arrangement of multiple injectors per combustion chamber
• CPC Class Codes: F02D 2200/701 Information about vehicle position, e.g. from navigation system or GPS signal
• CPC Class Codes: F02D 29/02 peculiar to engines driving vehicles; peculiar to engines driving variable pitch propellers
• 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
• CPC Class Codes: Y02T 10/62 Hybrid vehicles
• CPC Class Codes: Y10S 903/93 Conjoint control of different elements

Abstract

An internal combustion engine combusts a first fuel or a second fuel. A method for controlling the engine comprises supplying first fuel to at least one combustion chambers of the internal combustion engine, stopping the supply of the first fuel to the combustion chamber in response to an engine operating condition, and fueling with the second fuel to the at least one combustion chamber after a predetermined period, so as to maintain an engine speed within a predetermined range.

Claims

1. Method for controlling an internal combustion engine combusting a first fuel or a second fuel, the method comprising:

supplying the first fuel to at least one combustion chamber of said internal combustion engine;

stopping the supply of said first fuel to said at least one combustion chamber for a predetermined period;

maintaining a rotational speed of said internal combustion engine within a predetermined range during said predetermined period; and

fueling with the second fuel to said at least one combustion chamber after said predetermined period.

2. The method of claim 1, wherein said internal combustion engine is part of a vehicle powertrain having an electric motor capable of supplying torque to said internal combustion engine, and wherein the method further comprises increasing the torque of said electric motor to said internal combustion engine during said predetermined period.

3. The method of claim 1, wherein the rotational speed of said internal combustion engine is increased prior to said predetermined period.

4. The method of claim 1, wherein said internal combustion engine is part of a vehicle powertrain having an electric motor capable of generating torque to said internal combustion engine and a battery for storing and supplying electric energy to said electric motor, and wherein said maintaining the rotational speed of said internal combustion engine is performed by:

increasing the output torque of said electric motor during said period in response to a first operating condition of said battery; and

increasing the rotational speed of said internal combustion engine prior to said period in response to a second operating condition of said battery.

5. The method of claim 4, wherein said vehicle powertrain further comprises an electric generator driven by said internal combustion engine and generating electric energy to selectively supply it to said electric motor and said battery, and wherein the method is further comprised of:

after the rotational speed of said internal combustion engine is increased,

recovering and transforming kinetic energy of said internal combustion engine into electric energy through said electric generator as the rotational speed of said internal combustion engine is reduced; and

driving said electric motor with the electric energy supplied from said electric generator and said battery.

6. The method of claim 1, wherein said internal combustion engine is part of a vehicle powertrain having an electric motor capable of supplying torque to vehicle wheels, and wherein the method further comprises increasing the torque from said electric motor during said predetermined period.

7. The method of claim 6, wherein said vehicle powertrain further comprises a battery supplying electric energy to said electric motor and a generator driven by said internal combustion engine to generate and selectively supply electric energy to said electric motor and said battery, and wherein the method is further comprised of:

increasing the output torque of said electric motor during said period in response to a first operating condition of said battery;

increasing a rotational speed of said internal combustion engine prior to said period in response to a second operating condition of said battery;

recovering and transforming kinetic energy of said internal combustion engine into electric energy through said electric generator as the rotational speed of said internal combustion engine is reduced; and

driving said electric motor with the electric energy supplied from said electric generator and said battery.

8. The method of claim 1, wherein said first fuel is gasoline and said second fuel is gaseous hydrogen.

9. The method of claim 1, wherein said first fuel is stopped in response to an engine operating condition.

10. The method of claim 9, wherein said engine operating condition is determination to switch fuel from the first fuel to the second fuel based on driving condition of a vehicle equipped with said internal combustion engine.

11. Vehicle powertrain comprising:

an internal combustion engine combusting a first fuel or a second fuel;

a fuel supply system configured to selectively supply the first fuel or the second fuel into combustion chambers of said internal combustion engine;

an electric motor capable of supplying torque to said internal combustion engine; and

a control system configured to control said fuel supply system to;

supply the first fuel to at least one of said combustion chambers;

stop the supply of said first fuel to said at least one combustion chamber;

control said electric motor to increase its torque so as to maintain a rotational speed of said internal combustion engine within a predetermined range for a predetermined period; and

fuel with the second fuel to said at least one combustion chamber after said predetermined period.

12. Vehicle powertrain comprising:

an internal combustion engine combusting a first fuel or a second fuel;

a fuel supply system configured to selectively supply the first fuel or the second fuel into combustion chambers of said internal combustion engine; and

a control system configured to control said fuel supply system to;

supply the first fuel to at least one of said combustion chambers;

stop the supply of said first fuel to said at least one combustion chamber; and

fuel with the second fuel to said at least one combustion chamber after a predetermined period, and

wherein said control system is further configured to control said vehicle powertrain to maintain a rotational speed of said internal combustion engine within a predetermined range during said predetermined period.

13. The vehicle powertrain of claim 12, further comprising:

an electric motor capable of supplying torque to vehicle wheels; and

a battery for storing and supplying electric energy to said electric motor, and wherein said control system is further configured to;

increase the output torque of said electric motor during said predetermined period in response to a first operating condition of said battery; and

increase a rotational speed of said internal combustion engine prior to said period in response to a second operating condition of said battery.

14. The vehicle powertrain of claim 13, further comprising:

an electric generator driven by said internal combustion engine and generating electric energy to selectively supply it to said electric motor and said battery, and wherein said control system is further configured to;

after the rotational speed of said internal combustion engine is increased,

control said electric generator to recover and transform kinetic energy of said internal combustion engine into electric energy as the rotational speed of said internal combustion engine is reduced; and

control said electric generator and said battery to supply their electricity to said electric motor to drive it.

15. The vehicle powertrain of claim 12, further comprising an electric motor capable of supplying torque to vehicle wheels, and wherein said control system is further configured to control said electric motor to increase its driving torque during said predetermined period.

16. The vehicle powertrain of claim 15, further comprising:

a battery for storing and supplying electric energy to said electric motor; and

a generator driven by said internal combustion engine to generate and supply electric energy to said electric motor and said battery, and

wherein said control system is further configured to;

control said electric motor to increase its torque during said period in response to a first operating condition of said battery;

control said internal combustion engine to increase its rotational speed prior to said period in response to a second operating condition of said battery;

control said electric generator to recover and transform kinetic energy of said internal combustion engine into electric energy as the rotational speed of said internal combustion engine is reduced; and

drive said electric motor with the electric energy supplied from said electric generator and said battery.

17. The vehicle powertrain of claim 12, wherein said first fuel is gasoline and said second fuel is gaseous hydrogen.

18. The vehicle powertrain of claim 12, wherein said control system is further configured to control said internal combustion engine to rotate during said predetermined period to scavenge said at least one combustion chamber.

19. The vehicle powertrain of claim 12, wherein said control system is further configured to control said internal combustion engine to increase its rotational speed prior to said predetermined period.