Internal combustion engine

• US 4,337,740 A
• Filed: 06/18/1980
• Issued: 07/06/1982
• Est. Priority Date: 06/22/1979
• Status: Expired due to Term

• Current Assignee: Nissan Motor Co., Ltd.
• Original Assignee: Nissan Motor Co., Ltd.
• Inventors: Tanaka, Toshiaki, Iizuka, Haruhiko, Sugasawa, Fukashi, Etoh, Yukihiro
• Primary Examiner(s): Lall, P. S.
• Application Number:
  US06/160,564
• Time in Patent Office: 748 Days
• Field of Search: 123/481, 123/198 F, 123/568 R, 60/276, 60/285
• US Class Current: 123/672
• CPC Class Codes: F02D 17/02 Cutting-out cutting-out engines in multiple engine arrangements F02D25/04
• CPC Class Codes: F02D 41/0087 Selective cylinder activation, i.e. partial cylinder operation deceleration cut-off F02D41/123
• CPC Class Codes: F02D 43/00 Conjoint electrical control of two or more functions, e.g. ignition, fuel-air mixture, recirculation, supercharging or exhaust-gas treatment

Abstract

An internal combustion engine is disclosed which includes active and inactive cylinders, a load detector adapted to provide a low load indicative signal when the engine load is below a predetermined value, first means responsive to the low load indicative signal for cutting off the flow of air to the inactive cylinders, and second means for supplying a controlled amount of fuel into the active and inactive cylinders so as to achieve a somewhat lean air-fuel mixture therein. The second means is responsive to the low load indicative signal for cutting off the supply of fuel to the inactive cylinders and increasing the amount of fuel supplied to the active cylinders so as to achieve a somewhat rich air-fuel mixture therein. Third means is provided for monitoring the oxygen content of the exhaust from the engine to control the second means so that the fuel supplied to the engine is correct to maintain the stoichiometric air/fuel ratio.

Claims

1. An internal combustion engine comprising:

(a) first and second cylinder units, each said units including at least one cylinder;

(b) an intake passage having disposed therein a throttle valve and being divided downstream of said throttle valve into first and second branches communicating with said first and second cylinder units, respectively, said second branch having an intake entrance;

(c) a stop valve positioned generally in the vicinity of said intake entrance of said second branch;

(d) an exhaust gas sensor for providing a signal indicative of the air/fuel ratio at which said engine is operating;

(e) fuel supply means for supplying fuel to said first and second cylinder units, said fuel supply means including means responsive to engine loads for determining a basic value of fuel supply amount and means responsive to the air/fuel ratio indication signal from said exhaust gas sensor for correcting said basic value to maintain a desired air/fuel ratio;

(f) control means for cutting off the supply of fuel to said second cylinder unit to shift engine operation from a full engine mode into a split engine mode, and for closing said stop valve to shut off the flow of fresh air to said second cylinder unit, and for providing a low load indication signal when the engine load is below a predetermined value; and

(g) wherein said fuel supply means is responsive to the low load indication signal from said control unit for determining said basic value of fuel supply amount to create a mixture having an air/fuel ratio richer than said desired air/fuel ratio, whereby an air/fuel mixture leaner than said desired air/fuel mixture is obtained temporarily when the engine operation is shifted from a split engine mode into a full engine mode and an air/fuel mixture richer than said desired air/fuel mixture is obtained temporarily when the engine operation is shifted from the full engine mode into a split engine mode.

2. An internal combustion engine according to claim 1, wherein said fuel supply means determines the basic value of fuel supply amount from the product of the existing engine load and a first constant during a full engine mode of operation and determines the basic value of fuel supply amount from the product of the existing engine load and a second constant of a value larger than double said first constant during a split engine mode of operation.

3. An internal combustion engine according to claim 1, which further comprises means, responsive to the low load indicative signal from said control means, for recirculating exhaust gases into said intake passage second branch downstream of said stop valve.