Valve utilizing shape memory alloys and an anti-lock brake system with the valve
First Claim
1. A valve comprising:
- an electronic control unit for generating a first control current;
a housing having a first bore with a first inlet for introducing fluid from a fluid supply source and a first outlet for discharging the fluid to an operating object in an upper portion thereof, and a compartment in a lower portion thereof;
a first valve spool for closing the first inlet at a first position thereof, opening the first inlet at a second position thereof, and reciprocating between the first position and second position of said first valve spool;
biasing means for applying a biasing force upon said first valve spool; and
actuating means utilizing shape memory alloy wires for moving said first valve spool from the first position of said first valve spool to the second position of said first valve spool or from the second position of said first valve spool to the first position of said first valve spool by means of the first control current supplied from said electronic control unit, and opening or closing the first bore,wherein said biasing means is a plate spring installed at an inner sidewall of the compartment for applying an upward biasing force by a snap-through buckling to maintain said first valve spool to the first position of said first valve spool when said valve spool is placed on the first position of said first valve spool, and applying a downward biasing force by the snap-through buckling to maintain said first valve spool to the second position of said first valve spool when said valve spool is placed on the second position of said first valve spool.
1 Assignment
0 Petitions
Accused Products
Abstract
A valve (actuator) for performing pressurization, decompression and pressure maintenance drives plural spools movable up and down within a housing having plural bores by using linear shape memory alloys, and an anti-lock brake system utilizes the valve, in which respective bores have inlets and outlets, a mechanism for holding a lowering state of the spools is installed to the lower portion of the housing, and the spools return to their original positions by bias springs. A master cylinder, a wheel brake and a hydraulic pump are connected to the inlets and outlets of the valve of the anti-lock brake system and an electronic control unit is connected to the shape memory alloys to actuate the shape memory alloys, thereby attaining the operations of pressurization, decompression and pressure maintenance in connection with a brake pressure of the wheel brake.
102 Citations
10 Claims
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1. A valve comprising:
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an electronic control unit for generating a first control current; a housing having a first bore with a first inlet for introducing fluid from a fluid supply source and a first outlet for discharging the fluid to an operating object in an upper portion thereof, and a compartment in a lower portion thereof; a first valve spool for closing the first inlet at a first position thereof, opening the first inlet at a second position thereof, and reciprocating between the first position and second position of said first valve spool; biasing means for applying a biasing force upon said first valve spool; and actuating means utilizing shape memory alloy wires for moving said first valve spool from the first position of said first valve spool to the second position of said first valve spool or from the second position of said first valve spool to the first position of said first valve spool by means of the first control current supplied from said electronic control unit, and opening or closing the first bore, wherein said biasing means is a plate spring installed at an inner sidewall of the compartment for applying an upward biasing force by a snap-through buckling to maintain said first valve spool to the first position of said first valve spool when said valve spool is placed on the first position of said first valve spool, and applying a downward biasing force by the snap-through buckling to maintain said first valve spool to the second position of said first valve spool when said valve spool is placed on the second position of said first valve spool. - View Dependent Claims (2)
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3. An anti-lock brake system comprising:
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a master cylinder for generating a hydraulic pressure to a wheel brake attached to a wheel of a vehicle; a hydraulic regulator having a hydraulic pump for regulating the hydraulic pressure of said master cylinder, and a hydraulic motor for driving said hydraulic pump; an accumulator linked to said hydraulic pump for storing brake oil; a wheel-speed sensor attached to said wheel for sensing a wheel speed to generate a wheel-speed signal; a vehicle speed sensor for sensing a vehicle speed to generate a vehicle-speed signal; an electronic control unit for receiving the vehicle-speed signal and the wheel-speed signal, and calculating a difference between the vehicle-speed signal and the wheel-speed signal to generate a first control current, a second control current, a third control current, and a fourth control current; a first valve utilizing a plurality of shape memory alloys for introducing and discharging brake oil to said wheel brake so as to increase pressure of said wheel brake when the first control current is supplied, and for blocking brake oil being supplied to said wheel brake; and a second valve utilizing a plurality shape memory alloys for introducing and discharging brake oil from said wheel brake to said accumulator so as to decrease pressure of said wheel brake when the third control current is supplied, and for blocking brake oil being supplied to said wheel brake, wherein said first valve comprises; a first housing including a first bore formed in an upper portion thereof with a first inlet being connected between said master cylinder and said hydraulic pump in order to introduce brake oil from said master cylinder, and a first outlet being connected with said wheel brake in order to discharge the brake oil to said wheel brake, and a first compartment in a lower portion thereof; a first valve spool being movably installed within the first bore and connected with a first rod at lower portion thereof for closing the first inlet at a first position of said first valve spool, for opening the first inlet at a second position for said first valve spool; a first means for applying an upward biasing force to maintain said first valve spool at the first position of said first valve spool by means of snap-through buckling when said first valve spool is at the first position of said first valve spool, and for applying a downward biasing force to maintain said first valve spool at the second position of said first valve spool by means of snap-through buckling when said valve spool is at the second position of said first valve spool; a first shape memory alloy member for moving said first valve spool to the second position of said first valve spool while overcoming the upward biasing force of said first means when the first control current is supplied from said electronic control unit; and a second means for moving said first valve spool to the first position of said first valve spool while overcoming the downward biasing force of said first means when the second control current is supplied from said electronic control unit. - View Dependent Claims (4, 5, 6)
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7. An anti-lock brake system comprising:
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a master cylinder for generating a hydraulic pressure to a wheel brake attached to a wheel of a vehicle; a hydraulic regulator having a hydraulic pump for regulating the hydraulic pressure of said master cylinder, and a hydraulic motor for driving said hydraulic pump; an accumulator linked to said hydraulic pump for storing brake oil; a wheel-speed sensor attached to said wheel for sensing a wheel speed to generate a wheel-speed signal; a vehicle speed sensor for sensing a vehicle speed to generate a vehicle-speed signal; an electronic control unit for receiving the vehicle-speed signal and the wheel-speed signal, and calculating a difference between the vehicle-speed signal and the wheel-speed signal to generate a first control current, a second control current, a third control current, and a fourth control current; a first valve utilizing a plurality of shape memory alloys for introducing and discharging brake oil to said wheel brake so as to increase pressure of said wheel brake when the first control current is supplied, and for blocking brake oil being supplied to said wheel brake; and a second valve utilizing a plurality shape memory alloys for introducing and discharging brake oil from said wheel brake to said accumulator so as to decrease pressure of said wheel brake when the third control current is supplied, and for blocking brake oil being supplied to said wheel brake, wherein said second valve comprises; a second housing including a second bore formed in an upper portion thereof with a second inlet being connected between said wheel brake and said first valve in order to introduce brake oil from said wheel brake, and a second outlet being connected between said hydraulic pump and said accumulator in order to discharge the brake oil, and a second compartment in a lower portion thereof; a second valve spool being movably installed within the second bore and connected with a second rod at lower portion thereof for closing the second outlet at a first position of said second valve spool, for opening the second outlet at a second position for said second valve spool; a third means for applying an upward biasing force to maintain said second valve spool at the first position of said second valve spool by means of snap-through buckling when said second valve spool is at the first position of said second valve spool, and for applying a downward biasing force to maintain said second valve spool at the second position of said second valve spool by means of snap-through buckling when said second valve spool is at the second position of said second valve spool; a third shape memory alloy member for moving said second valve spool to the second position of said second valve spool while overcoming the upward biasing force of said third means when the third control current is supplied from said electronic control unit; and a fourth means for moving said second valve spool to the first position of aid second valve spool while overcoming the downward biasing force of said third means when the fourth control current is supplied from said electronic control unit. - View Dependent Claims (8, 9, 10)
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Specification