Microvalve for electronically controlled transmission
First Claim
1. An electronically controlled automatic transmission, comprising:
- an input shaft;
an output shaft;
a plurality of gears providing driving connection between said input shaft and said output shaft;
one of a hydraulically operated brake band and a hydraulically operated clutch which is operable to effect a change in the gear reduction provided by said gears between said input shaft and said output shaft;
a source of pressurized hydraulic fluid; and
a microvalve device selectively operable to control passage of pressurized hydraulic fluid from said source to said one of a hydraulically operated brake band and a hydraulically operated clutch to operate said one of a hydraulically operated brake band and a hydraulically operated clutch, wherein said microvalve device includes a micro-machined pilot valve and a micro-machined pilot-operated valve controlled by the operation of said pilot valve.
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0 Petitions
Accused Products
Abstract
A microvalve device for controlling fluid flow in a fluid circuit. The microvalve device comprises a body having a cavity formed therein. An electronically controlled automatic transmission, comprising of an input shaft; an output shaft; a plurality of gears providing driving connection between the input shaft and the output shaft; one of a hydraulically operated brake band and a hydraulically operated clutch which is operable to effect a change in the gear reduction provided by the gears between the input shaft and the output shaft; a source of pressurized hydraulic fluid; and a microvalve device selectively operable to control passage of pressurized hydraulic fluid from the source to the one of a hydraulically operated brake band and a hydraulically operated clutch to operate the one of a hydraulically operated brake band and a hydraulically operated clutch.
120 Citations
20 Claims
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1. An electronically controlled automatic transmission, comprising:
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an input shaft;
an output shaft;
a plurality of gears providing driving connection between said input shaft and said output shaft;
one of a hydraulically operated brake band and a hydraulically operated clutch which is operable to effect a change in the gear reduction provided by said gears between said input shaft and said output shaft;
a source of pressurized hydraulic fluid; and
a microvalve device selectively operable to control passage of pressurized hydraulic fluid from said source to said one of a hydraulically operated brake band and a hydraulically operated clutch to operate said one of a hydraulically operated brake band and a hydraulically operated clutch, wherein said microvalve device includes a micro-machined pilot valve and a micro-machined pilot-operated valve controlled by the operation of said pilot valve. - View Dependent Claims (2)
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3. An electronically controlled automatic transmission, comprising:
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an input shaft;
an output shaft;
a plurality of gears providing driving connection between said input shaft and said output shaft;
at least one hydraulically operated component which is operable to effect a change in the gear reduction provided by said gears between said input shaft and said output shaft;
a source of pressurized hydraulic fluid; and
a microvalve device selectively operable to control passage of pressurized hydraulic fluid from said source to said hydraulically operated component, said microvalve device including a microvalve having an outlet in fluid communication with said hydraulically operated component, said microvalve being operable to control passage of pressurized hydraulic fluid from said source to said hydraulically operated component, said microvalve device further including a MEMS pressure detector for generating a signal indicative of a pressure of said fluid at said outlet, wherein said microvalve is a pilot operated valve, said electronically controlled automatic transmission further including a microvalve acting as a pilot valve for controlling the operation of said microvalve. - View Dependent Claims (4, 5, 6, 7, 8)
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9. A microvalve device for controlling fluid pressure in an electrically controlled automatic transmission comprising:
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a valve body defining an inlet adapted to be connected to a source of pressurized fluid in an automatic transmission and defining an outlet adapted to be connected in fluid communication with a hydraulically operated component of the automatic transmission, said valve body further defining a pilot valve inlet adapted to be connected to the source of pressurized fluid and a fluid passage;
a pilot operated valve disposed between said inlet and said outlet, said pilot operated valve having a first position permitting pressurized hydraulic fluid to pass from said inlet to said outlet, and a second position preventing pressurized hydraulic fluid to pass from said inlet to said outlet, said pilot operated valve having a control face in fluid communication with said fluid passage, said pilot operated valve being operated between said first and second positions according to the pressure in said fluid passage; and
a pilot valve disposed in said passage, said pilot valve being operable between a first position in which pressurized fluid is prevented from passing from said pilot valve inlet to said passage and a second position in which pressurized fluid is permitted to pass from said pilot valve inlet to said passage to increase pressure in said passage. - View Dependent Claims (10, 11, 12, 13, 14, 15, 16, 17, 18, 19)
where P1=supply pressure to said pressure divider circuit;
P2=control pressure directed to said control face;
A1=opening area of an upstream orifice of said pressure divider circuit; and
A2=opening area of a downstream orifice of said pressure dividing circuit.
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17. The microvalve device of claim 12, wherein said pressure detector is a MEMS strain gauge bonded to an outer surface of said valve body.
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18. The microvalve device of claim 12, further including an Electronic Control Unit producing an electrical signal for controlling the position of said pilot valve, said signal indicative of pressure at solid outlet being provided to said Electronic Control Unit for closed loop control of said microvalve device.
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19. The microvalve device of claim 18, wherein said Electronic Control Unit and said valve body are mounted on a common substrate.
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20. A microvalve device for controlling fluid pressure, comprising:
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a microvalve valve body defining an inlet adapted to be connected to a source of pressurized fluid and defining an outlet adapted to be connected in fluid communication with a hydraulically operated component, said valve body further defining a pilot valve inlet adapted to be connected to the source of pressurized fluid and defining a fluid passage;
a pilot operated microvalve disposed between said inlet and said outlet, said pilot operated microvalve having a first position permitting pressurized hydraulic fluid to pass from said inlet to said outlet, and a second position preventing pressurized hydraulic fluid to pass from said inlet to said outlet, said pilot operated microvalve having a control face in fluid communication with said fluid passage, said pilot operated microvalve being operated between said first and second positions according to the pressure in said fluid passage; and
a pilot microvalve disposed in said fluid passage, said pilot microvalve being operable between a first position in which pressurized fluid is prevented from passing from said pilot microvalve inlet to said fluid passage and a second position in which pressurized fluid is permitted to pass from said pilot microvalve inlet to said fluid passage to increase pressure in said fluid passage.
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Specification