Method of reduction of exhaust gas emissions from internal combustion engines

• US 6,550,239 B2
• Filed: 08/31/2001
• Issued: 04/22/2003
• Est. Priority Date: 03/05/1999
• Status: Expired due to Term

• Current Assignee: Volvo Car Corporation (AB Volvo)
• Original Assignee: Volvo Car Corporation (AB Volvo)
• Inventors: Almkvist, Göran, Fredriksson, Krister
• Primary Examiner(s): Denion, Thomas
• Assistant Examiner(s): NGUYEN, TU MINH
• Application Number:
  US09/682,432
• Publication Number:
  US 20020033016A1
• Time in Patent Office: 599 Days
• Field of Search: 602/74, 602/77, 602/84, 602/85, 123/2, 123/192.1, 123/192.2, 123/179.16, 123/179.3, 123/339.1, 123/339.14, 123/339.16, 123/339.17, 123/339.18, 290/40.A, 290/22
• US Class Current: 60/284
• CPC Class Codes: F02D 41/062 for starting F02D41/061 takes precedence

Abstract

A method for reducing harmful and toxic exhaust gases from an internal combustion engine. The engine includes at least one cylinder to which an air/fuel mixture is supplied when a crankshaft of the internal combustion engine is rotated. The method includes supplying an air/fuel mixture with a lambda value greater than one to the cylinder, and controlling the pressure in the intake channel by an electric motor/generator coupled to the crankshaft. When the pressure in the intake channel exceeds a predetermined pressure, the electric motor/generator is controlled in such a way that the pressure in the intake channel can decrease, and when the pressure in the intake channel falls below a predetermined pressure, the electric motor/generator is controlled in such a way that the pressure in the intake channel can increase.

Claims

1. A method for reducing harmful and toxic exhaust gases from an internal combustion engine having at least one cylinder supplied by an air/fuel mixture when a crankshaft of the internal combustion engine rotates, comprising the steps of:

supplying an air/fuel mixture with a lambda value of greater than one to the cylinder, and

controlling the pressure in the intake channel by means of an electric motor/generator coupled to the crankshaft,

wherein when the pressure in the intake channel exceeds a predetermined pressure, the electric motor/generator is controlled so that the pressure in the intake channel can decrease, and when the pressure in the intake channel falls below a predetermined pressure, the electric motor/generator is controlled so that the pressure in the intake channel can increase.

2. The method according to claim 1 wherein the pressure in the intake channel is maintained substantially constant by controlling the electric motor/generator such that the crankshaft rotates at a substantially constant rotation speed.

3. The method according to claim 1 wherein the electric motor/generator drives the crankshaft for a predetermined time without fuel being supplied to the internal combustion engine, thereby generating an underpressure in the intake channel before the internal combustion engine is started.

4. The method according to claim 1, further comprising the step of detecting the temperature of a catalyzer arranged on the internal combustion engine,

wherein when the temperature of the catalyzer corresponds to or exceeds a predetermined temperature, the electric motor/generator drives the crankshaft for a predetermined time without fuel being supplied to the internal combustion engine, thereby ventilating fuel present in the intake channel and the cylinder.

5. The method according to claim 1 further comprising the step of controlling the internal combustion engine by a control unit which receives signals from the internal combustion engine and which emits signals to a control device for the electric motor/generator.

6. The method according to claim 1 wherein the lambda value of the air/fuel mixture supplied to the cylinder lies in the range of about 1.1 to about 1.4.

7. The method according to claim 6 wherein the lambda value of the air/fuel mixture supplied to the cylinder lies in the range of about 1.1 to about 1.2.

8. The method according to claim 1 wherein the method is used for cold starting of the internal combustion engine.

9. A method for reducing harmful and toxic exhaust gases from an internal combustion engine having at least one cylinder supplied by an air/fuel mixture when a crankshaft of the internal combustion engine rotates, comprising the steps of:

supplying an air/fuel mixture with a lambda value of greater than one to the cylinder, and

controlling the pressure in the intake channel by means of an electric motor/generator coupled to the crankshaft,

wherein when the pressure in the intake channel exceeds a predetermined pressure, the electric motor/generator is controlled so that the pressure in the intake channel can decrease, and when the pressure in the intake channel falls below a predetermined pressure, the electric motor/generator is controlled so that the pressure in the intake channel can increase, and

wherein the method is used for cold starting of the internal combustion engine.

10. A method for reducing harmful and toxic exhaust gases from an internal combustion engine having at least one cylinder supplied by an air/fuel mixture when a crankshaft of the internal combustion engine rotates, the method comprising the steps of:

supplying an air/fuel mixture with a lambda value of greater than one to the cylinder, and

controlling the pressure in the intake channel by means of an electric motor/generator coupled to the crankshaft,

wherein when the pressure in the intake channel exceeds a predetermined pressure, the electric motor/generator is controlled so that the pressure in the intake channel can decrease, and

wherein when the pressure in the intake channel falls below a predetermined pressure, the electric motor/generator is controlled so that the pressure in the intake channel can increase,

whereby the lambda value of the air/fuel mixture supplied to the cylinder is maintained substantially constant.

11. A method for reducing harmful and toxic exhaust gases from an internal combustion engine having at least one cylinder supplied by an air/fuel mixture when a crankshaft of the internal combustion engine rotates, the method comprising the steps of:

supplying an air/fuel mixture with a lambda value of greater than one to the cylinder,

controlling the pressure in the intake channel by means of an electric motor/generator coupled to the crankshaft, and

driving the crankshaft with the electric motor/generator for a predetermined time without supplying fuel to the internal combustion engine, thereby generating an under pressure in the intake channel before the internal combustion engine is started,

wherein when the pressure in the intake channel exceeds a predetermined pressure, the electric motor/generator is controlled so that the pressure in the intake channel can decrease, and when the pressure in the intake channel falls below a predetermined pressure, the electric motor/generator is controlled so that the pressure in the intake channel can increase.

12. The method according to claim 11 wherein the pressure in the intake channel is maintained substantially constant by controlling the electric motor/generator such that the crankshaft rotates at a substantially constant rotation speed.

13. The method according to claim 11, further comprising the step of detecting the temperature of a catalyzer arranged on the internal combustion engine,

wherein when the temperature of the catalyzer corresponds to or exceeds a predetermined temperature, the electric motor/generator drives the crankshaft for a predetermined time without supplying fuel to the internal combustion engine, thereby ventilating fuel present in the intake channel and the cylinder.

14. The method according to claim 11, further comprising the step of controlling the internal combustion engine by a control unit that receives signals from the internal combustion engine and emits signals to a control device for the electric motor/generator.

15. The method according to claim 11 wherein the lambda value of the air/fuel mixture supplied to the cylinder lies in the range of about 1.1 to about 1.4.

16. The method according to claim 15 wherein the lambda value of the air/fuel mixture supplied to the cylinder lies in the range of about 1.1 to about 1.2.

17. The method according to claim 11 wherein the method is used for cold starting of the internal combustion engine.

18. A method for reducing harmful and toxic exhaust gases from an internal combustion engine having at least one cylinder supplied by an air/fuel mixture when a crankshaft of the internal combustion engine rotates, the method comprising the steps of:

supplying an air/fuel mixture with a lambda value of greater than one to the cylinder,

controlling the pressure in the intake channel by means of an electric motor/generator coupled to the crankshaft, and

detecting the temperature of a catalyzer arranged on the internal combustion engine,

wherein when the temperature of the catalyzer corresponds to or exceeds a predetermined temperature, the electric motor/generator drives the crankshaft for a predetermined time without supplying fuel to the internal combustion engine, thereby ventilating fuel present in the intake channel and the cylinder, and

wherein when the pressure in the intake channel exceeds a predetermined pressure, the electric motor/generator is controlled so that the pressure in the intake channel can decrease, and when the pressure in the intake channel falls below a predetermined pressure, the electric motor/generator is controlled so that the pressure in the intake channel can increase.

19. The method according to claim 18 wherein the pressure in the intake channel is maintained substantially constant by controlling the electric motor/generator such that the crankshaft rotates at a substantially constant rotation speed.

20. The method according to claim 18, further comprising the step of driving the crankshaft with the electric motor/generator for a predetermined time without supplying fuel to the internal combustion engine, thereby generating an under pressure in the intake channel before the internal combustion engine.

21. The method according to claim 18, further comprising the step of controlling the internal combustion engine by a control unit that receives signals from the internal combustion engine and emits signals to a control device for the electric motor/generator.

22. The method according to claim 18 wherein the lambda value of the air/fuel mixture supplied to the cylinder lies in the range of about 1.1 to about 1.4.

23. The method according to claim 18 wherein the lambda value of the air/fuel mixture supplied to the cylinder lies in the range of about 1.1 to about 1.2.

24. The method according to claim 18 wherein the method is used for cold starting of the internal combustion engine.