Thermally actuated microvalve device

• US 6,994,115 B2
• Filed: 01/24/2005
• Issued: 02/07/2006
• Est. Priority Date: 03/22/2000
• Status: Expired due to Term

• Current Assignee: NovaSensor, Inc. (General Electric Company), Kelsey-Hayes Co. (Zeppelin - Stiftung der Stadt Friedrichshafen)
• Original Assignee: Kelsey-Hayes Co. (Zeppelin - Stiftung der Stadt Friedrichshafen)
• Inventors: Hunnicutt, Harry A.
• Primary Examiner(s): Krishnamurthy, Ramesh
• Application Number:
  US11/041,479
• Publication Number:
  US 20050121090A1
• Time in Patent Office: 379 Days
• Field of Search: 137/625.44, 137/625.65, 251/11, 251/281
• US Class Current: 137/625.65
• CPC Class Codes: B60T 8/366 Valve details
• CPC Class Codes: B60T 8/3695 wherein the pilot valve is mounted separately from its power section B60T8/3605, B60T8/361 and B60T8/3615 take precedence
• CPC Class Codes: B60T 8/42 having expanding chambers for controlling pressure , i.e. closed systems
• CPC Class Codes: B60T 8/4275 Pump-back systems
• CPC Class Codes: F15B 13/0402 for linearly sliding valves, e.g. spool valves
• CPC Class Codes: F15B 13/0438 the pilot valves being of the nozzle-flapper type
• CPC Class Codes: F15C 5/00 Manufacture of fluid circuit elements; Manufacture of assemblages of such elements integrated circuits
• CPC Class Codes: F16K 2099/0076 using electrical discharge machining [EDM], milling or drilling
• CPC Class Codes: F16K 99/0001 Microvalves microdevices B81B1/00; manufacture or treatment of devices or systems in or on a substrate B81C1/00; microfluidic structures B01L3/5027; micropumps F04B19/006
• CPC Class Codes: F16K 99/0011 Gate valves or sliding valves
• CPC Class Codes: F16K 99/0059 actuated by a pilot fluid
• CPC Class Codes: G05D 7/0694 by action on throttling means or flow sources of very small size, e.g. microfluidics microvalves F16K99/0001; microstructural devices per se B81B
• CPC Class Codes: Y10T 137/86622 Motor-operated
• CPC Class Codes: Y10T 137/86847 Pivoted valve unit
• CPC Class Codes: Y10T 137/87209 Electric

Abstract

A microvalve having a generally planar plate valve body defining a chamber and a plate valve member movable in the chamber about a pivot axis that is perpendicular to the valve body to control the flow of a fluid through the valve body. The plate valve member defines a pair of opposite faces, a first duct therethrough provides fluid communication between the opposite faces to equalize fluid pressures acting on the opposite faces in the region of the first duct. The plate valve member also has a second duct therethrough that provides fluid communication between the opposite faces to equalize fluid pressures acting on the opposite faces in the region of the second duct. The first duct and the second duct are equidistant from the pivot axis.

Claims

1. A microvalve comprising:

a generally planar plate valve body defining a chamber; and

a plate valve member movable in said chamber about a pivot axis perpendicular to said valve body to control the flow of a fluid through said valve body, said plate valve member defining a pair of opposite faces, a first duct therethrough providing fluid communication between said opposite faces to equalize fluid pressures acting on said opposite faces in the region of said first duct, and a second duct therethrough providing fluid communication between said opposite faces to equalize fluid pressures acting on said opposite faces in the region of said second duct, said first duct and said second duct being equidistant from said pivot axis.

2. The microvalve defined in claim 1, said valve body further defining a first port communicating with said chamber which is adapted to be connected to a source of high pressure fluid, and defining a second port communicating with said chamber which is adapted to be connected to a low pressure reservoir, said plate valve member being movable to a position in which said first duct is in fluid communication with said first port, and said second duct is in fluid communication with said second port.

3. The microvalve defined in claim 2, wherein said plate valve member is “

T-shaped”

, comprising a main shaft connected to said pivot and a cross-member having a first end portion defining said first duct, a second end portion defining said second duct, and a middle portion between said first and second end portions fixed to said main shaft.

4. A micromachined device, comprising:

a body comprising a plurality of plates defining a plurality of parallel planes, said body defining a chamber within at least one intermediate plate and a fluid port communicating with said chamber; and

a member movable in said chamber within a plane parallel to said plurality of parallel planes, said member having a first portion and a second portion, said member being movable within a fixed range of movement such that only said first portion of the member is adjacent to said fluid port within said fixed range of movement, said member defining a pair of opposite faces, and further defining a vent through said second portion providing fluid communication between said opposite faces of said member to equalize fluid pressures acting on said opposite faces of said member.

5. The micromachined device defined in claim 4, wherein said member is a valve member movable to control the flow of a fluid through said fluid port.

6. The micromachined device defined in claim 5, wherein said valve member is “

T-shaped”

, comprising a main shaft connected to a pivot and a cross-member comprising said first portion, and a third portion, said second portion being disposed between said first portion and said third portion, said first portion having a first duct defined therethrough, said third portion defining a second duct defined therethrough, said body defining a second fluid port in fluid communication with said chamber, only said third portion of said member being adjacent to said second fluid port within said fixed range of movement.

7. The micromachined device defined in claim 6, wherein said member is movable, within said fixed range of motion, to a first position in which said first duct is in unrestricted fluid communication with said fluid port and said second duct is in restricted fluid communication with said second fluid port, and movable to a second position in which said first duct is in restricted fluid communication with said fluid port and said second duct is in unrestricted fluid communication with said second fluid port.

8. The micromachined device defined in claim 6, wherein said vent is formed through said second portion adjacent said first duct, and further including a second vent defined through said second portion adjacent said second duct providing fluid communication between said opposite faces of said member to equalize fluid pressures acting on said opposite faces of said member.

9. The micromachined device defined in claim 6, wherein said vent is formed through said second portion adjacent said first duct, and further including a second vent defined through said second portion adjacent said vent providing fluid communication between said opposite faces of said member to equalize fluid pressures acting on said opposite faces of said member.

10. The micromachined device defined in claim 6, wherein said vent is formed through said second portion adjacent said first duct, and wherein said vent is one of a pair of laterally spaced apart vents formed through said second portion adjacent said first duct, and further including a second pair of laterally spaced apart vents defined through said second portion adjacent said second duct providing fluid communication between said opposite faces of said member to equalize fluid pressures acting on said opposite faces of said member.