Variable valve type internal combustion engine and control method thereof

• US 7,240,664 B2
• Filed: 04/21/2004
• Issued: 07/10/2007
• Est. Priority Date: 04/21/2003
• Status: Expired due to Term

• Current Assignee: Hitachi Astemo Ltd. (Hitachi, Ltd.)
• Original Assignee: Hitachi, Ltd.
• Inventors: Yoshida, Takashi, Sukegawa, Yoshihiro
• Primary Examiner(s): Huynh; Hai
• Application Number:
  US10/828,225
• Publication Number:
  US 20040206334A1
• Time in Patent Office: 1,175 Days
• Field of Search: 123/399, 123/90.15, 123/90.16, 123/90.17, 123/302, 123/308, 123/345, 123/346, 123/432
• US Class Current: 123/346
• CPC Class Codes: F02B 2031/006 having multiple air intake valves
• CPC Class Codes: F02B 2275/16 Indirect injection
• CPC Class Codes: F02B 31/085 having two inlet valves
• CPC Class Codes: F02D 13/0226 changing valve lift or valve lift and timing
• CPC Class Codes: F02D 2041/001 for engines with variable valve actuation
• CPC Class Codes: F02D 41/0002 Controlling intake air
• CPC Class Codes: F02D 41/3094 the fuel injection being effected by at least two different injectors, e.g. one in the intake manifold and one in the cylinder
• CPC Class Codes: Y02T 10/12 Improving ICE efficiencies
• CPC Class Codes: Y02T 10/40 Engine management systems

Abstract

The operation modes of plural intake valves 7a and 7b provided in one cylinder is independently changed according to the drive region of the internal combustion engine. In the low air amount region, the intake airflow is controlled only with intake valve 7a which operates in the low air amount region and the other intake valve 7b is operated in the medium and high air amount regions.

Claims

1. A variable valve type internal combustion engine in which the intake airflow is controlled with a plurality of intake valves, comprising a plurality of intake ports provided in each cylinder, an intake valve which individually opens and shuts each intake port, a variable valve gear which continuously and changeably sets at least one of the lift amount and the open valve period of each intake valve, and a control means in which at least one of the lift amount and the open valve period of plural intake valves can be set independently for each intake valve, and the operation modes of said plural intake valves in one cylinder can be set respectively and independently according to the operating states of the internal combustion engine,

wherein said control means stops at least one of said plural intake valves provided in one cylinder in a low air amount region and operates at least one other of said plural intake valves in the low air amount region, and at least two of the plural intake valves are operated in medium and high air amount regions.

2. A variable valve type internal combustion engine according to claim 1, wherein the diameters of at least two of the intake valves provided in one cylinder are different from each other.

3. A variable valve type internal combustion engine according to claim 2, wherein said control means stops the intake valve with a large diameter among said plural intake valves provided in one cylinder in the low air amount region.

4. A variable valve type internal combustion engine according to claim 3, wherein said control means operates all of said plural intake valves provided in one cylinder in the medium and high air amount region.

5. A variable valve type internal combustion engine according to claim 4, wherein said control means decreases the intake airflow with the intake valve which operates in the low air amount region, and increases the intake airflow with the intake valve which operates in the medium and high air amount region during transition which shifts from the low air amount region to the high air amount region.

6. A variable valve type internal combustion engine according to claim 5, wherein during transition which shifts from the low air amount region to the medium and the high air amount region, said control means changes the magnitude of the decrease of the air amount which passes through the intake valve which operates in the low air amount region according to the operating state before the transition and the operating state after the transition based on the driver'"'"'s intention.

7. A variable valve type internal combustion engine according to claim 5, wherein according to the operating state before the transition and the operating state after the transition based on the driver'"'"'s intention, the air amount which passes through the intake valve which operates in the low load operation region is decreased compared with the air amount before the transition, and the increase in the air amount which passes through the intake valve which operates in the high load operation region compared with the air amount before the transition is prohibited.

8. A variable valve type internal combustion engine according to claim 4, wherein said control means decreases the intake airflow with the intake valve which operates in the medium and the high air amount regions, and increases the intake airflow with the intake valve which operates in the low air amount region during transition which shifts from the high air amount region to the low air amount region.

9. A variable valve type internal combustion engine according to claim 3, wherein said control means operates the intake valve with a large diameter among said plural intake valves provided in one cylinder, and stops the intake valve with a small diameter in the medium air amount region, and operates all of said plural intake valves provided in one cylinder in the high air amount region.

10. A variable valve type internal combustion engine according to claim 3, wherein when the operation valve is switched from the intake valve which operates in the low air amount region to the intake valve which operates in the high air amount region, the minimum intake airflow of the intake valve which operates in the high air amount region is more than the maximum intake airflow of the intake valve which operates in the low air amount region.

11. A variable valve type internal combustion engine according to claim 1, further comprising a means which generates a negative pressure upstream of the intake valve in the low air amount region, wherein the control of the intake airflow in the low air amount region is performed by using one intake valve among said plural intake valves provided in one cylinder.

12. A variable valve type internal combustion engine according to claim 1, wherein a fuel injection valve is provided individually in each of said plural intake ports provided in one cylinder.

13. A variable valve type internal combustion engine according to claim 12, wherein a fuel injection amount to each of the plural intake port is decided depending on the air amount which passes through each of the intake valves provided in one cylinder.

14. A method of controlling a variable valve type internal combustion engine in which the intake airflow is controlled with a plurality of intake valves, comprising a plurality of intake ports provided in each cylinder, an intake valve which individually opens and shuts each intake port, and a variable valve gear which continuously and changeably sets at least one of the lift amount and the open valve period of each of the intake valves, wherein at least one of said plural intake valves provided in one cylinder is stopped in a low air amount region and at least one of said plural intake valves is operated in the low air amount region, and at least two of the plural intake valves are operated in medium and high air amount regions.

15. A variable valve type internal combustion engine in which the intake airflow is controlled with a plurality of intake valves, comprising a plurality of intake ports provided in each cylinder, an intake valve which individually opens and shuts each intake port, and a variable valve gear which continuously and changeably sets at least one of the lift amount and the open valve period of each intake valve, further comprising a controller in which at least one of the lift amount and the open valve period of plural intake valves can be set independently for each intake valve, and the operation modes of said plural intake valves in one cylinder can be set respectively and independently according to the operating states of the internal combustion engine, further comprising

a negative pressure generator which generates a negative pressure upstream of the intake valve in the low air amount region, wherein the control of the intake airflow in the low air amount region is performed by using one intake valve among said plural intake valves provided in one cylinder.

16. A variable valve type internal combustion engine according to claim 15, wherein the negative pressure generator is a throttle valve upstream of the intake valve.