Idle and off-idle operation of a two-stroke fuel-injected multi-cylinder internal combustion engine

• US 4,991,558 A
• Filed: 01/03/1989
• Issued: 02/12/1991
• Est. Priority Date: 01/03/1989
• Status: Expired due to Fees

• Current Assignee: Siemens AG, Siemens Automotive LP (Siemens AG)
• Original Assignee: Siemens Automotive LP (Siemens AG)
• Inventors: Verner, Douglas R., Daly, Paul D., Brooks, Mark A., Fallis, Robert E.
• Primary Examiner(s): Argenbright, Tony M.
• Assistant Examiner(s): Mates, Robert E.
• Application Number:
  US07/461,557
• Time in Patent Office: 770 Days
• Field of Search: 123/73 A, 123/73 C, 123/198 F, 123/481
• US Class Current: 123/481
• CPC Class Codes: F02B 2075/025 two
• CPC Class Codes: F02D 17/02 Cutting-out cutting-out engines in multiple engine arrangements F02D25/04
• CPC Class Codes: F02D 2200/0404 Throttle position
• CPC Class Codes: F02D 2200/0406 Intake manifold pressure
• CPC Class Codes: F02D 2200/101 Engine speed
• CPC Class Codes: F02D 2400/04 Two-stroke combustion engines with electronic control
• CPC Class Codes: F02D 41/0087 Selective cylinder activation, i.e. partial cylinder operation deceleration cut-off F02D41/123
• CPC Class Codes: F02D 41/08 for idling F02D41/06, F02D41/16 take precedence
• CPC Class Codes: F02D 41/182 for the control of a fuel injection device
• CPC Class Codes: F02D 41/2406 using essentially read only memories
• CPC Class Codes: F02D 41/3058 the engine working with a variable number of cycles

Abstract

A multiple cylinder two-stroke fuel-injected internal combustion engine is operated at idle by interrupting the fuel injection stages in a predetermined pattern such that over a certain number of crankshaft revolutions a fewer number of injections occur than over the same number of revolutions at non-idle. The quantity of fuel injected per injection is increased relative to that required to operate the engine at idle wihtout any injection interruptions. Spark timing is also advanced.

Claims

1. In a multiple-cylinder, two-stroke, fuel-injected internal combustion engine, means for operating the engine at idle which comprises means for interrupting the fuel injection stages in a predetermined pattern such that over a certain number of engine crankshaft revolutions a fewer number of injection stages occur than over the same number of engine crankshaft revolutions during non-idle operation, and means for increasing the quantity of fuel injected per injection stage relative to the quantity of fuel required per injection stage to secure idle operation without any injection interruptions.

3. A method for engine idle operation of a multiple-cylinder, two-cycle, fuel injected internal combustion engine, said method comprising:

interrupting the fuel injection stages in a predetermined pattern such that over a certain number of engine crankshaft revolutions a fewer number of injection stages occur than over the same number of engine crankshaft revolutions during non-idle operation, and increasing the quantity of fuel injected per injection stage relative to the quantity of fuel required per injection stage to secure idle operation without any injection interruptions.

4. The method as set forth in claim 3 including advancing the spark timing during idle operation in comparison to the spark timing that is appropriate for idle operation without any interruption of the injection stages.

5. A method for engine idle operation of a six-cylinder, two-stroke, fuel-injected internal combustion engine which operates at non-idle in a manner such that the fuel is injected into each cylinder during the fuel injection stage of consecutive two-stroke cycles of the cylinder, said method for engine idle operation comprising:

interrupting the fuel injection stages of the cylinders from that which occurs at non-idle engine operation in such a pattern that over a certain number of engine crankshaft revolutions the interruptions in each individual cylinder are caused to occur at non-consecutive two-stroke cycles and the interruptions in the sequence of injection from cylinder to cylinder are caused to occur non-consecutively, with said method further comprising the interruptions and injections occurring in the following repeating sequence that covers five-sixths of an engine crankshaft revolution;

interrupt, inject, inject, interrupt, inject.

6. A method for engine idle operation of a four-cylinder, two-stroke, fuel-injected internal combustion engine which operates at non-idle in a manner such that the fuel is injected into each cylinder during the fuel injection stage of consecutive two-stroke cycles of the cylinder, said method for engine idle operation comprising:

interrupting the fuel injection stages of the cylinders from that which occurs at non-idle engine operation in such a pattern that over a certain number of engine crankshaft revolutions the interruptions in each individual cylinder are caused to occur at non-consecutive two-stroke cycles and the interruptions in the sequence of injection from cylinder to cylinder are caused to occur non-consecutively, with said method further comprising the interruptions and injections occurring in the following repeating sequence that covers one and one-fourth engine crankshaft revolutions;

inject, interrupt, inject, inject, interrupt.

7. In a six-cylinder, two-stroke, fuel-injected internal combustion engine which comprises means for causing operation at non-idle in a manner such that the fuel is injected into each cylinder during the fuel injection stage of consecutive two-stroke cycles of the cylinder, the means for operating the engine at idle which comprises:

means for interrupting the fuel injection stages of the cylinders from that which occurs at non-idle engine operation in such a pattern that over a certain number of engine crankshaft revolutions the interruptions in each individual cylinder are caused to occur at non-consecutive two-stroke cycles and the interruptions in the sequence of injection from cylinder to cylinder are caused to occur non-consecutively, and the means for interrupting the fuel injection stages of the cylinders comprises means for causing the injections and interruptions to occur in the following repeating sequence that covers five-sixths of an engine crankshaft revolution;

interrupt, inject, inject, interrupt, inject.

8. In a four-cylinder, two-stroke, fuel-injected internal combustion engine which comprises means for causing operation at non-idle in a manner such that the fuel is injected into each cylinder during the fuel injection stage of consecutive two-stroke cycles of the cylinder, the means for operating the engine at idle which comprises:

means for interrupting the fuel injection stages of the cylinders from that which occurs at non-idle engine operation in such a pattern that over a certain number of engine crankshaft revolutions the interruptions in each individual cylinder are caused to occur at non-consecutive two-stroke cycles and the interruptions in the sequence of injection from cylinder to cylinder are caused to occur non-consecutively, and the means for interrupting the fuel injection stages of the cylinders comprises means for causing the injections and interruptions to occur in the following repeating sequence that covers one and one-forth engine crankshaft revolutions;

inject, interrupt, inject, inject, interrupt.

9. A method for engine idle operation of a six-cylinder, two-stroke, fuel-injected internal combustion engine which operates at non-idle in a manner such that the fuel is injected into each cylinder during the fuel injection stage of consecutive two-stroke cycles of the cylinder, said method for engine idle operation comprising:

interrupting the fuel injection stages of the cylinders from that which occurs at non-idle engine operation in such a pattern that over a certain number of engine crankshaft revolutions the injections into each individual cylinder are caused to occur at non-consecutive two-stroke cycles and the injections in the sequence of injection from cylinder to cylinder are caused to occur non-consecutively with said method further comprising the interruptions and injections occurring in the following repeating sequence that covers five-sixths of an engine crankshaft revolution;

inject, interrupt, interrupt, inject, interrupt.

10. A method for engine idle operation of a four-cylinder, two-stroke, fuel-injected internal combustion engine which operates at non-idle in a manner such that the fuel is injected into each cylinder during the fuel injection stage of consecutive two-stroke cycles of the cylinder, said method for engine idle operation comprising:

interrupting the fuel injection stages of the cylinders from that which occurs at non-idle engine operation in such a pattern that over a certain number of engine crankshaft revolutions the injections into each individual cylinder are caused to occur at non-consecutive two-stroke cycles and the injections in the sequence of injection from cylinder to cylinder are caused to occur non-consecutively with said method further comprising the interruptions and injections occurring in the following repeating sequence that covers one and one-fourth engine crankshaft revolutions;

interrupt, inject, interrupt, interrupt, inject.

11. In a six-cylinder, two-stroke, fuel-injected internal combustion engine which comprises means for causing operation at non-idle in a manner such that the fuel is injected into each cylinder during the fuel injection stage of consecutive two-stroke cycles of the cylinder, the means for operating the engine at idle which comprises:

means for interrupting the fuel injection stages of the cylinders from that which occurs at non-idle engine operation in such a pattern that over a certain number of engine crankshaft revolutions the injections in each individual cylinder are caused to occur at non-consecutive two-stroke cycles and the injections in the sequence of injection from cylinder to cylinder are caused to occur non-consecutively, and the means for interrupting the fuel injection stages of the cylinders comprises means for causing the injections and interruptions to occur in the following repeating sequence that covers five-sixths of an engine crankshaft revolution;

inject, interrupt, interrupt, inject, interrupt.

12. In a four-cylinder, two-stroke, fuel-injected internal combustion engine which comprises means for causing operation at non-idle in a manner such that the fuel is injected into each cylinder during the fuel injection stage of consecutive two-stroke cycles of the cylinder, the means for operating the engine at idle which comprises:

means for interrupting the fuel injection stages of the cylinders from that which occurs at non-idle engine operation in such a pattern that over a certain number of engine crankshaft revolutions the injections in each individual cylinder are caused to occur at non-consecutive two-stroke cycles and the injections in the sequence of injection from cylinder to cylinder are caused to occur non-consecutively, and the means for interrupting the fuel injection stages of the cylinders comprises means for causing the injections and interruptions to occur in the following repeating sequence that covers one and one-fourth engine crankshaft revolutions;

interrupt, inject, interrupt, interrupt, inject.

13. A method for engine idle operation of a multiple-cylinder, two-stroke, fuel-injected internal combustion engine which operates at non-idle in a manner such that the fuel is injected into each cylinder during the fuel injection stage of consecutive two-stroke cycles of the cylinder, said method for engine idle operation comprising:

interrupting the fuel injection stages of the cylinders from that which occurs at non-idle engine operation in such a pattern that over a certain number of engine crankshaft revolutions the interruptions in each individual cylinder are caused to occur at non-consecutive two-stroke cycles and the interruptions in the sequence of injection from cylinder to cylinder are caused to occur non-consecutively, with said method further comprising the interruptions and injections occurring in a repeating sequence that spans a certain continuum of engine crankshaft revolution, said sequence being characterized in that an injection occurs at one limit of the sequence and an interruption occurs at the opposite limit of the sequence and in that said sequence comprises two consecutive injections.

2. An internal combustion engine as set forth in claim 13 including means for advancing the spark timing during idle operation in comparison to the spark timing that is appropriate for idle operation without any interruption of the injection stages.

14. In a multi-cylinder, two-stroke, fuel-injected internal combustion engine which comprises means for causing operation at non-idle in a manner such that the fuel is injected into each cylinder during the fuel injection stage of consecutive two-stroke cycles of the cylinder, the means for operating the engine at idle which comprises:

means for interrupting the fuel injection stages of the cylinders from that which occurs at non-idle engine operation in such a pattern that over a certain number of engine crankshaft revolutions the interruptions in each individual cylinder are caused to occur at non-consecutive two-stroke cycles and the interruptions in the sequence of injection from cylinder to cylinder are caused to occur non-consecutively, and the means for interrupting the fuel injection stages of the cylinders comprises means for causing the injections and interruptions to occur in a repeating sequence that spans a certain continuum of engine crankshaft revolution, said sequence being characterized in that an injection occurs at one limit of the sequence and an interruption occurs at the opposite limit of the sequence and in that said sequence comprises two consecutive injections.

15. A method for engine idle operation of a multiple-cylinder, two-stroke, fuel-injected internal combustion engine which operates at non-idle in a manner such that the fuel is injected into each cylinder during the fuel injection stage of consecutive two-stroke cycles of the cylinder, said method for engine idle operation comprising:

interrupting the fuel injection stages of the cylinders from that which occurs at non-idle engine operation in such a pattern that over a certain number of engine crankshaft revolutions the interruptions in each individual cylinder are caused to occur at non-consecutive two-stroke cycles and the interruptions in the sequence of injection from cylinder to cylinder are caused to occur non-consecutively, with said method further comprising the interruptions and injections occurring in a repeating sequence that spans a certain continuum of engine crankshaft revolution, said sequence being characterized in that an injection occurs at one limit of the sequence and an interruption occurs at the opposite limit of the sequence, in that said sequence comprises plural injections, in that said plural injections are non-consecutive, and in that said sequence comprises a pattern of injections and interruptions other than a pattern that is sub-divisible into identical sub-sequences.

16. In a multi-cylinder, two-stroke, fuel-injected internal combustion engine which comprises means for causing operation at non-idle in a manner such that the fuel is injected into each cylinder during the fuel injection stage of consecutive two-stroke cycles of the cylinder, the means for operating the engine at idle which comprises:

means for interrupting the fuel injection stages of the cylinders from that which occurs at non-idle engine operation in such a pattern that over a certain number of engine crankshaft revolutions the interruptions in each individual cylinder are caused to occur at non-consecutive two-stroke cycle and the interruptions in the sequence of injection from cylinder to cylinder are caused to occur non-consecutively, and the means for interrupting the fuel injection stages of the cylinders comprises means for causing the injections and interruptions to occur in a repeating sequence that spans a certain continuum of engine crankshaft revolution, said sequence being characterized in that an injection occurs at one limit of the sequence and an interruption occurs at the opposite limit of the sequence, in that said sequence comprises plural injections, in that said plural injections are non-consecutive, and in that said sequence comprises a pattern of injections and interruptions other than a pattern that is sub-divisible into identical sub-sequences.