Fuel injection control apparatus for an internal combustion engine

• US 5,492,101 A
• Filed: 12/12/1994
• Issued: 02/20/1996
• Est. Priority Date: 12/13/1993
• Status: Expired due to Term

• Current Assignee: Nippon Soken, Inc., Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Nippon Soken, Inc., Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Morino, Tetsuya, Takeda, Keiso, Saito, Kimitaka
• Primary Examiner(s): ARGENBRIGHT, TONY MICHAEL
• Application Number:
  US08/354,798
• Time in Patent Office: 435 Days
• Field of Search: 123/478, 123/480, 123/491, 123/492, 123/493
• US Class Current: 123/491
• CPC Class Codes: F02B 2275/14 Direct injection into combustion chamber
• CPC Class Codes: F02D 2041/1433 using a model or simulation of the system
• CPC Class Codes: F02D 41/047 Taking into account fuel evaporation or wall wetting; special correction after fuel cut-off F02D41/126
• CPC Class Codes: F02D 41/1401 characterised by the control or regulation method F02D41/1473, F02D41/1477 take precedence
• CPC Class Codes: F02D 41/221 relating to the failure of actuators or electrically driven elements
• CPC Class Codes: Y02T 10/12 Improving ICE efficiencies

Abstract

A fuel injection valve 15 is disposed in an intake passage 9 of an engine body 1. A combustion chamber 5 communicates with the intake passage 9 for introducing fuel injected from the fuel injection valve 15 at predetermined intake timings. A plurality of sensors are provided in the engine body 1 or fuel intake system for detecting various engine operational conditions including properties of fuel. A control unit 30 calculates a fuel quantity-of-state in the combustion chamber 5 in accordance with the engine operational conditions detected by the sensors, using an atomized fuel behavioral model representing behavior of fuel injected from the fuel injection valve 15, an intake passage fuel behavioral model representing fuel behavior in the intake passage 9 and a combustion chamber fuel behavioral model representing fuel behavior in the combustion chamber 5. Furthermore, the control unit 30 calculates a fuel injection amount required to adjust an actual gaseous air-fuel ratio in the combustion chamber 5 to a desired value in accordance with the fuel quantity-of-state thus calculated. The control unit 30 uses a cranking model as the combustion chamber fuel behavioral model before an initial explosion is detected and uses a firing model after the initial explosion is detected. The fuel injection valve 15 is opened or closed on the basis of the fuel injection amount thus calculated.

Claims

1. A fuel injection control apparatus for an internal combustion engine comprising:

a fuel injection valve disposed in an intake passage;

a combustion chamber communicated with the intake passage for introducing fuel injected from the fuel injection valve at predetermined intake timings;

operational condition detecting means for detecting various operational conditions including properties of fuel;

fuel quantity-of-state calculating means for calculating a fuel quantity-of-state in the combustion chamber in accordance with the operational conditions detected by the operational condition detecting means, using an atomized fuel behavioral model representing behavior of fuel injected from the fuel injection valve, an intake passage fuel behavioral model representing fuel behavior in the intake passage and a combustion chamber fuel behavioral model representing fuel behavior in the combustion chamber;

injection amount calculating means for calculating a fuel injection amount required to adjust an actual gaseous air-fuel ratio in the combustion chamber to a desired value in accordance with the fuel quantity-of-state calculated by the fuel quantity-of-state calculating means; and

injection valve actuating means for opening and closing the fuel injection valve on the basis of the fuel injection amount calculated by the injection amount calculating means.

2. The fuel injection control apparatus in accordance with claim 1, wherein the combustion chamber fuel behavioral model includes a cranking model representing fuel behavior during a first period from start-up of engine to an initial explosion and a firing model representing fuel behavior during a second period succeeding the first period, said cranking model being selected in the beginning of the engine starting operation, and being switched to the firing model upon detection of the initial explosion.

3. The fuel injection control apparatus in accordance with claim 2, wherein, if leakage of fuel from the fuel injection valve is detected during a dormant period of the engine, such a leakage amount is reflected to determination of an initial value of the cranking model.

4. The fuel injection control apparatus in accordance with claim 1, wherein the combustion chamber fuel behavioral model takes account of a combustion chamber inflow fuel amount including a fuel amount adhering on a wall of the combustion chamber and a fuel amount vaporized in the combustion chamber.

5. The fuel injection control apparatus in accordance with claim 1, wherein the combustion chamber fuel behavioral model divides a combustion chamber inflow fuel amount F_o into three, a fuel amount α

_d ·

F_o adhering on a wall of a cylinder of the combustion chamber, a fuel amount α

_c ·

F_o adhering on other wall of the combustion chamber and a fuel amount β

_c ·

F_o vaporized in the combustion chamber, where α

_d +α

_c +β

_c =1.

6. The fuel injection control apparatus in accordance with claim 1, wherein the combustion chamber fuel behavioral model takes account of a combustion chamber adhesion fuel amount M_c including a fuel amount γ

_c ·

M_c vaporized in the combustion chamber and a fuel amount γ

_e ·

M_c carried over to the exhaust passage.

7. The fuel injection control apparatus in accordance with claim 1, wherein the combustion chamber fuel behavioral model takes account of a gaseous fuel amount residing in the combustion chamber without being burnt in a cranking operation.

8. A fuel injection control apparatus for an internal combustion engine comprising:

a fuel injection valve disposed in a combustion chamber so that fuel is directly injected from the fuel injection valve into the combustion chamber;

operational condition detecting means for detecting various operational conditions including properties of fuel;

fuel quantity-of-state calculating means for calculating a fuel quantity-of-state in the combustion chamber in accordance with the operational conditions detected by the operational condition detecting means, using an atomized fuel behavioral model representing behavior of fuel injected from the fuel injection valve and a combustion chamber fuel behavioral model representing fuel behavior in the combustion chamber;

injection amount calculating means for calculating a fuel injection amount required to adjust an actual gaseous air-fuel ratio in the combustion chamber to a desired value in accordance with the fuel quantity-of-state calculated by the fuel quantity-of-state calculating means; and

injection valve actuating means for opening and closing the fuel injection valve on the basis of the fuel injection amount calculated by the injection amount calculating means.

9. The fuel injection control apparatus in accordance with claim 8, wherein the combustion chamber fuel behavioral model includes a cranking model representing fuel behavior during a first period from start-up of engine to an initial explosion and a firing model representing fuel behavior during a second period succeeding the first period, said cranking model being selected in the beginning of the engine starting operation, and being switched to the firing model upon detection of the initial explosion.

10. The fuel injection control apparatus in accordance with claim 9, wherein, if leakage of fuel from the fuel injection valve is detected during a dormant period of the engine, such a leakage amount is reflected to determination of an initial value of the cranking model.

11. The fuel injection control apparatus in accordance with claim 8, wherein the combustion chamber fuel behavioral model takes account of a combustion chamber inflow fuel amount including a fuel amount adhering on a wall of the combustion chamber and a fuel amount vaporized in the combustion chamber.

12. The fuel injection control apparatus in accordance with claim 8, wherein the combustion chamber fuel behavioral model divides a combustion chamber inflow fuel amount F_o into three, a fuel amount α

_d ·

F_o adhering on a wall of a cylinder of the combustion chamber, a fuel amount α

_c ·

F_o adhering on other wall of the combustion chamber and a fuel amount β

_c ·

F_o vaporized in the combustion chamber, where α

_d +α

_c +β

_c =1.

13. The fuel injection control apparatus in accordance with claim 8, wherein the combustion chamber fuel behavioral model further takes account of a combustion chamber adhesion fuel amount M_c including a fuel amount γ

_c ·

M_c vaporized in the combustion chamber and a fuel amount γ

_c ·

M_c carried over to the exhaust passage.

14. The fuel injection control apparatus in accordance with claim 8, wherein the combustion chamber fuel behavioral model takes account of a gaseous fuel amount residing in the combustion chamber without being burnt in a cranking operation.