Electronically actuated valve system

• US 20080251044A1
• Filed: 04/13/2007
• Published: 10/16/2008
• Est. Priority Date: 04/13/2007
• Status: Active Grant

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Riley, William, Schrader, Michael, Zagata, Mark, McConville, Greg
• Granted Patent: US 7,578,270 B2
• Time in Patent Office: Days
• US Class Current: 123/188.8
• CPC Class Codes: F01L 1/185 Overhead end-pivot rocking arms
• CPC Class Codes: F01L 1/46 Component parts, details, or accessories, not provided for in preceding subgroups
• CPC Class Codes: F01L 13/0015 for optimising engine performances by modifying valve lift according to various working parameters, e.g. rotational speed, load, torque
• CPC Class Codes: F01L 2301/00 Using particular materials
• CPC Class Codes: F01L 2820/01 Absolute values
• CPC Class Codes: F01L 3/10 Connecting springs to valve members

Abstract

An electronically actuated valve assembly for an internal combustion engine is disclosed, wherein the valve assembly comprises a valve stem, a shape memory alloy actuator in operative communication with the valve stem, a coolant passage through which at least a portion of the shape memory alloy actuator extends, and a cooling fluid source in communication with the coolant passage.

Claims

1. An electronically actuated valve assembly for an internal combustion engine, the valve assembly comprising:

a valve stem;

a shape memory alloy actuator in operative communication with the valve stem;

a coolant passage through which at least a portion of the shape memory alloy actuator extends; and

a cooling fluid source in communication with the coolant passage.

2. The valve assembly of claim 1, wherein the coolant passage is configured to accept a flow of engine oil.

3. The valve assembly of claim 1, wherein the coolant passage is coupled to an engine coolant circulation system.

4. The valve assembly of claim 1, wherein the coolant passage is coupled to a dedicated shape memory alloy coolant source.

5. The valve assembly of claim 1, further comprising an arm member to which the valve stem and the shape memory alloy actuator are coupled.

6. The valve assembly of claim 5, further comprising a pivot disposed on the arm member, wherein the shape memory alloy actuator is coupled with the arm member in a location intermediate the pivot and the valve stem.

7. The valve assembly of claim 5, wherein the shape memory alloy actuator comprises a shape memory alloy wire having a length greater than a length of the valve stem.

8. The valve assembly of claim 1, wherein the shape memory alloy actuator has a length equal to or less than the length of the valve stem.

9. The valve assembly of claim 1, wherein the shape memory alloy actuator comprises a plurality of shape memory alloy wires.

10. An electronically actuated valve assembly for an internal combustion engine, the valve assembly comprising:

an arm member;

a pivot disposed at a first location on the arm member;

a valve stem coupled to the arm member at a second location on the arm member;

a shape memory alloy actuator operatively coupled with the arm member at a location between the valve stem and the pivot; and

a coolant passage through which a portion of the shape memory alloy extends.

11. The valve assembly of claim 10, wherein the shape memory alloy actuator comprises a shape memory alloy wire.

12. The valve assembly of claim 11, wherein the shape memory alloy actuator comprises a plurality of shape memory alloy wires.

13. The valve assembly of claim 10, wherein the shape memory alloy actuator comprises a shape memory alloy member with a length greater than a length of the valve stem.

14. The valve assembly of claim 10, wherein the coolant passage is coupled to an engine oil circulation system.

15. The valve assembly of claim 10, wherein the coolant passage is coupled to an engine coolant circulation system.

16. The valve assembly of claim 10, wherein the coolant passage is coupled to a dedicated shape memory alloy coolant source.

17. In an apparatus comprising an internal combustion engine with an electronic valve actuation system, the valve actuation system comprising a shape memory alloy, a method of operating the actuator, comprising:

causing a first change of flow of an electrical current through the shape memory alloy, thereby causing a first dimensional change in the shape memory alloy; and

causing a second change of flow of an electrical current through the shape memory alloy and exposing the shape memory alloy to a cooling fluid, thereby causing a second dimensional change in the shape memory alloy.

18. The method of claim 17, wherein exposing the shape memory alloy to the cooling fluid comprises exposing the shape memory alloy to engine oil.

19. The method of claim 17, wherein exposing the shape memory alloy to the cooling fluid comprises exposing the shape memory alloy to an engine coolant.

20. The method of claim 17, wherein exposing the shape memory alloy to the cooling fluid comprises exposing the shape memory alloy to a dedicated shape memory alloy coolant.

21. The method of claim 17, wherein the shape memory alloy extends through a cooling fluid passage, and wherein exposing the shape memory alloy to the cooling fluid comprises flowing the cooling fluid through the passage.

22. The method of claim 17, wherein causing a first change of flow of an electric current comprises applying a voltage to the shape memory alloy.

23. The apparatus of claim 17, wherein causing a first change of flow of an electric current comprises changing a duty cycle of a signal applied to the shape memory alloy.