Multistage fuel-injection internal combustion engine

• US 20070074702A1
• Filed: 09/14/2006
• Published: 04/05/2007
• Est. Priority Date: 09/30/2005
• Status: Active Grant

• Current Assignee: Hitachi Astemo Ltd. (Hitachi, Ltd.)
• Original Assignee: Hitachi, Ltd.
• Inventors: Watanabe, Masahiko, Nakamura, Makoto, Hara, Seinosuke, Suga, Seiji, Hokari, Tomio
• Granted Patent: US 7,520,260 B2
• Time in Patent Office: Days
• US Class Current: 123/299
• CPC Class Codes: F01N 11/002 the diagnostic devices measuring or estimating temperature or pressure in, or downstream of the exhaust apparatus
• CPC Class Codes: F01N 13/009 having two or more separate purifying devices arranged in series
• CPC Class Codes: F01N 3/035 with catalytic reactors , e.g. catalysed diesel particulate filters
• CPC Class Codes: F01N 3/106 Auxiliary oxidation catalysts
• CPC Class Codes: F02B 37/18 by bypassing exhaust from the inlet to the outlet of turbine or to the atmosphere
• CPC Class Codes: F02B 37/24 by using pumps or turbines with adjustable guide vanes
• CPC Class Codes: F02D 2041/001 for engines with variable valve actuation
• CPC Class Codes: F02D 41/402 Multiple injections
• CPC Class Codes: F02M 45/086 Having more than one injection-valve controlling discharge orifices
• CPC Class Codes: F02M 63/0225 Fuel-injection apparatus having a common rail feeding several injectors F02M63/0003 takes precedence; Means for varying pressure in common rails; Pumps feeding common rails
• CPC Class Codes: Y02T 10/40 Engine management systems

Abstract

In a multi-stage fuel-injection internal combustion engine employing a fuel injection system and a variable valve actuation system, engine valve timings are variably controlled depending on engine operating conditions. An electronic engine control unit is configured to execute cooperative control of the timing of sub-injection, injected before main injection, responsively to intake valve closure timing, and also to execute cooperative control of the timing of sub-injection, injected after the-main injection, responsively to exhaust valve open timing.

Claims

1. A multi-stage fuel-injection internal combustion engine comprising:

a fuel injection system enabling at least one sub-injection in addition to main injection;

a variable valve actuation control system capable of changing intake valve closure timing or exhaust valve open timing; and

a control unit being responsive to operating conditions of the engine, for executing cooperative control of sub-injection timing responsively to either one of the intake valve closure timing and the exhaust valve open timing.

5. The multi-stage fuel-injection internal combustion engine as claimed in claim 1, wherein:

the timing of sub-injection, injected before the main injection, is phase-retarded responsively to a phase advance of the intake valve closure timing of the variable valve actuation control system, in a very light load and low speed range substantially corresponding to idling.

6. The multi-stage fuel-injection internal combustion engine as claimed in claim 1, wherein:

the timing of sub-injection, injected before the main injection, is phase-retarded responsively to a phase retard of the intake valve closure timing of the variable valve actuation control system, in a light load range.

7. The multi-stage fuel-injection internal combustion engine as claimed in claim 1, wherein:

the timing of sub-injection, injected before the main injection, is phase-advanced responsively to a phase advance of the intake valve closure timing of the variable valve actuation control system, in a high load and low speed range.

8. The multi-stage fuel-injection internal combustion engine as claimed in claim 1, wherein:

the timing of sub-injection, injected before the main injection, is phase-advanced responsively to a phase retard of the intake valve closure timing of the variable valve actuation control system, in a high load and high speed range.

9. The multi-stage fuel-injection internal combustion engine as claimed in claim 1, wherein:

the timing of sub-injection, injected after the main injection, is phase-advanced responsively to a phase advance of the exhaust valve open timing of the variable valve actuation control system, in a high speed range.

10. The multi-stage fuel-injection internal combustion engine as claimed in claim 1, wherein:

the timing of sub-injection, injected after the main injection, is phase-retarded responsively to a phase retard of the exhaust valve open timing of the variable valve actuation control system, in a low speed range.

11. The multi-stage fuel-injection internal combustion engine as claimed in claim 1, wherein:

the timing of sub-injection, injected after the main injection, is phase-advanced responsively to a phase retard of the exhaust valve open timing of the variable valve actuation control system, under a condition where a catalyst temperature is excessively high.

12. The multi-stage fuel-injection internal combustion engine as claimed in claim 1, wherein:

the timing of sub-injection, injected after the main injection, is phase-retarded responsively to a phase advance of the exhaust valve open timing of the variable valve actuation control system, during cold engine operation.

2. A multi-stage fuel-injection internal combustion engine comprising:

a fuel injection system capable of injecting fuel at a plurality of injection timings in one operating cycle of the engine;

a variable valve actuation control system capable of changing intake valve closure timing or exhaust valve open timing by changing a valve lift characteristic or valve-open and valve-closure timings of at least one of an intake valve and an exhaust valve; and

a control unit configured to define at least two domains of a specified engine operating region as a first operating range and a second operating range and to set one of the injection timings to have a predetermined first relation with either one of the intake valve closure timing and the exhaust valve open timing in the first operating range and to set one of the injection timings to have a predetermined second relation with either one of the intake valve closure timing and the exhaust valve open timing in the second operating range.

3. A multi-stage fuel-injection internal combustion engine comprising:

a fuel injection system capable of injecting fuel at a plurality of injection timings in one operating cycle of the engine;

a variable valve actuation control system capable of changing intake valve closure timing or exhaust valve open timing by changing a valve lift characteristic or valve-open and valve-closure timings of at least one of an intake valve and an exhaust valve;

a sensor provided to detect the valve lift characteristic or the valve-open and valve-closure timings of at least one of the intake and exhaust valves; and

a control unit being responsive to a sensor signal from the sensor, for executing cooperative control of one of the injection timings responsively to either one of the intake valve closure timing and the exhaust valve open timing.

4. A multi-stage fuel-injection internal combustion engine comprising:

a fuel injection system enabling at least one sub-injection in addition to main injection;

a variable valve actuation control system capable of changing intake valve closure timing or exhaust valve open timing;

a first sensor provided to detect operating conditions of the engine;

a second sensor provided to detect a valve lift characteristic or valve-open and valve-closure timings of at least one of an intake valve and an exhaust valve; and

a control unit configured to initiate cooperative control of sub-injection timing responsively to either one of the intake valve closure timing and the exhaust valve open timing, when a difference between the intake valve closure timing detected by the second sensor and a desired intake valve closure timing value determined based on the engine operating conditions detected by the first sensor becomes greater than or equal to a predetermined threshold value or when a difference between the exhaust valve open timing detected by the second sensor and a desired exhaust valve open timing value determined based on the engine operating conditions detected by the first sensor becomes greater than or equal to the predetermined threshold value.

13. A multi-stage fuel-injection internal combustion engine comprising:

a fuel injection system enabling at least sub-injection injected before main injection and sub-injection injected after the main injection;

a first variable valve actuation mechanism capable of changing at least intake valve closure timing;

a second variable valve actuation mechanism capable of changing at least exhaust valve open timing; and

a control unit being responsive to operating conditions of the engine, for executing cooperative control of the timing of the first sub-injection, injected before the main injection, responsively to the intake valve closure timing, and for executing cooperative control of the timing of the second sub-injection, injected after the main injection, responsively to the exhaust valve open timing.

14. The multi-stage fuel-injection internal combustion engine as claimed in claim 13, wherein:

the timing of the first sub-injection, injected before the main injection, is phase-retarded responsively to a phase advance of the intake valve closure timing of the first variable valve actuation mechanism, in a very light load and low speed range substantially corresponding to idling.

15. The multi-stage fuel-injection internal combustion engine as claimed in claim 13, wherein:

the timing of the first sub-injection, injected before the main injection, is phase-retarded responsively to a phase retard of the intake valve closure timing of the first variable valve actuation mechanism, in a light load range.

16. The multi-stage fuel-injection internal combustion engine as claimed in claim 13, wherein:

the timing of the first sub-injection, injected before the main injection, is phase-advanced responsively to a phase advance of the intake valve closure timing of the first variable valve actuation mechanism, in a high load and low speed range.

17. The multi-stage fuel-injection internal combustion engine as claimed in claim 13, wherein:

the timing of the first sub-injection, injected before the main injection, is phase-advanced responsively to a phase retard of the intake valve closure timing of the first variable valve actuation mechanism, in a high load and high speed range.

18. The multi-stage fuel-injection internal combustion engine as claimed in claim 13, wherein:

the timing of the second sub-injection, injected after the main injection, is phase-advanced responsively to a phase advance of the exhaust valve open timing of the second variable valve actuation mechanism, in a high speed range.

19. The multi-stage fuel-injection internal combustion engine as claimed in claim 13, wherein:

the timing of the second sub-injection, injected after the main injection, is phase-retarded responsively to a phase retard of the exhaust valve open timing of the second variable valve actuation mechanism, in a low speed range.

20. The multi-stage fuel-injection internal combustion engine as claimed in claim 13, wherein:

the timing of the second sub-injection, injected after the main injection, is phase-advanced responsively to a phase retard of the exhaust valve open timing of the second variable valve actuation mechanism, under a condition where a catalyst temperature is excessively high.

21. The multi-stage fuel-injection internal combustion engine as claimed in claim 13, wherein:

the timing of the second sub-injection, injected after the main injection, is phase-retarded responsively to a phase advance of the exhaust valve open timing of the second variable valve actuation mechanism, during cold engine operation.