Air induction control system for variable displacement internal combustion engine

• US 6,363,907 B1
• Filed: 10/11/2000
• Issued: 04/02/2002
• Est. Priority Date: 10/15/1999
• Status: Expired due to Fees

• Current Assignee: Nissan Motor Co., Ltd.
• Original Assignee: Nissan Motor Co., Ltd.
• Inventors: Arai, Masahiro, Nagaishi, Hatsuo
• Primary Examiner(s): Kamen, Noah P.
• Application Number:
  US09/686,992
• Time in Patent Office: 538 Days
• Field of Search: 123/198.F, 123/21, 123/90.11
• US Class Current: 123/198.00F
• CPC Class Codes: F01L 9/20 by electric means
• CPC Class Codes: F02D 2041/0012 with selective deactivation of cylinders
• CPC Class Codes: F02D 2200/0402 the parameter being determined by using a model of the engine intake or its components
• CPC Class Codes: F02D 41/0002 Controlling intake air
• CPC Class Codes: F02D 41/0087 Selective cylinder activation, i.e. partial cylinder operation deceleration cut-off F02D41/123
• CPC Class Codes: F02D 41/1401 characterised by the control or regulation method F02D41/1473, F02D41/1477 take precedence
• CPC Class Codes: Y02T 10/40 Engine management systems

Abstract

A control system for a variable displacement internal combustion engine determines effective flow cross sectional area as a predetermined function of a cross sectional area given against a throttle position. The effective flow cross sectional area is used to determine a volumetric airflow ratio. A control unit is connected with cylinder operator means for deactivating and reactivating at least some of engine cylinders and varying strokes in a cycle. The control unit modifies the predetermined function in response to the number of cylinders being activated and the number of strokes in a current cycle.

Claims

1. A control system for an internal combustion engine having a plurality of cylinders, comprising:

engine cylinder operator means for varying displacement of the engine cylinders;

means generating a cross sectional area against a given throttle position out of stored various cross sectional areas against various throttle positions;

means for determining an effective flow cross sectional area as a predetermined function of said cross sectional area;

means for generating a maximum airflow ratio corresponding to said effective flow cross sectional area; and

means for modifying said predetermined function in response to a change in displacement of the engine cylinders.

2. The control system as claimed in claim 1, wherein said cylinder operator means deactivate and reactivate at least some of the engine cylinders, and said predetermined function modifying means use the number of cylinders being activated in modifying said predetermined function.

3. The control system as claimed in claim 2, wherein said cylinder operator means include electromagnetic valve operators for opening and closing cylinder valves.

4. The control system as claimed in claim 1, wherein said cylinder operator means vary the number of strokes in a cycle, and said predetermined function modifying means calculate a ratio between the number of strokes in a current cycle and the number of strokes in a standard cycle and use said ratio in modifying said predetermined function.

5. The control system as claimed in claim 4, wherein said cylinder operator means include electromagnetic valve operators for opening and closing cylinder valves.

6. A method of calculating airflow entering a multicylinder internal combustion engine, the method comprising:

deactivating and reactivating at least some of the engine cylinders;

generating a cross sectional area against a given throttle position out of stored various cross sectional areas against various throttle positions;

determining an effective flow cross sectional area as a predetermined function of said cross sectional area;

generating a volumetric airflow ratio corresponding to said effective flow cross sectional area; and

modifying said predetermined function in response to the number of cylinder being activated.

7. A method of calculating airflow entering a multicylinder internal combustion engine, the method comprising:

varying the number of strokes in a cycle of the engine cylinders;

determining the number of strokes in a current cycle;

generating a cross sectional area against a given throttle position out of stored various cross sectional areas against various throttle positions;

determining an effective flow cross sectional area as a predetermined function of said cross sectional area;

generating a volumetric airflow ratio corresponding to said effective flow cross sectional area; and

modifying said predetermined function in response to the determined number of strokes in current cycle.

8. A control system for an internal combustion engine having a plurality of cylinders, comprising:

engine cylinder operator means for deactivating and reactivating the engine cylinders; and

a control unit connected with said engine cylinder operator means,

said control unit generating a cross sectional area against a given throttle position out of stored various cross sectional areas against various throttle positions;

said control unit determining an effective flow cross sectional area as a predetermined function of said cross sectional area;

said control unit generating a volumetric airflow ratio corresponding to said effective flow cross sectional area; and

said control unit modifying said predetermined function in response to the number of engine cylinders being activated.

9. The control system as claimed in claim 8, wherein said engine cylinder operator means include electromagnetic valve operators for opening and closing cylinder valves.

10. A control system for an internal combustion engine having a plurality of cylinders, comprising:

engine cylinder operator means for varying the number of strokes in a cycle; and

a control unit connected with said engine cylinder operator means,

said control unit generating a cross sectional area against a given throttle position out of stored various cross sectional areas against various throttle positions;

said control unit determining an effective flow cross sectional area as a predetermined function of said cross sectional area;

said control unit generating a volumetric airflow ratio corresponding to said effective flow cross sectional area; and

said control unit modifying said predetermined function in response to the number of strokes in cycle.

11. The control system as claimed in claim 10, wherein said control unit calculates a ratio between the number of strokes in a current cycle and the number of strokes in a standard cycle and uses said ratio in modifying said predetermined function.

12. The control system as claimed in claim 10, wherein said engine cylinder operator means include electromagnetic valve operators for opening and closing cylinder valves.

13. The control system as claimed in claim 10, wherein said control unit gives a throttle position in response to an accelerator control position of a manually operable accelerator.

14. A control system for an internal combustion engine having a plurality of cylinders, comprising:

engine cylinder operator means for deactivating and reactivating the engine cylinders and varying the number of strokes in a cycle; and

a control unit connected with said engine cylinder operator means,

said control unit generating a cross sectional area against a given throttle position out of stored various cross sectional areas against various throttle positions;

said control unit determining an effective flow cross sectional area as a predetermined function of said cross sectional area;

said control unit generating a volumetric airflow ratio corresponding to said effective flow cross sectional area;

said control unit calculates the product of the volumetric airflow ratio and a maximum air induction to give the result as a target base airflow; and

said control unit modifying said predetermined function in response to the number of engine cylinders being activated and the number of strokes in cycle.

15. The control system as claimed in claim 14, wherein said control unit calculates a ratio between the number of strokes in a current cycle and the number of strokes in a standard cycle and uses said ratio in modifying said predetermined function.

16. The control system as claimed in claim 14, wherein, when all of the engine cylinders are being activated with strokes in the standard cycle, said predetermined function is expressed such that the effective flow cross sectional area is equivalent to the cross sectional area divided by the total of displacements of the engine cylinders and also by engine speed.