Abstract:
A valve is disclosed and comprises a main valve body having first and second ports and a movable poppet positioned within the main valve body. The movable poppet is moveable from a first closed position in which the poppet establishes a fluid-tight seal with a sealing member, which is effective to prevent fluid flow from the first port to the second port, to a second open position in which the poppet is spaced apart from the sealing member and fluid is permitted to flow from the first port to the second port. The valve also has a piezoelectric actuator engaged with the poppet and effective to move the poppet from the first closed position to the second open position. Methods of use of the valve are also disclosed.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    The present invention relates, in general, to a multi-function valve usable in a variety of different circumstances. 
         [0002]    Valves and valve systems are available to function for pressure-relief purposes, pressure-reduction, or pressure regulation. Existing valves, however, typically focus on one of the foregoing functionalities. The valves can have a mechanical or electronic control system. Mechanical valves have fast response and relatively large flow capacity, but their excessive size and weight prohibits them from use in many applications. Moreover, mechanical valves have one set point, which cannot be changed remotely. On the other hand, electronic control valves, due to the performance of the actuator generally used therewith, are limited to low-flow or slow-response applications. Often a separate control system relying on the feedback from a sensor apart from a main valve unit is required. 
         [0003]    A need therefore exists for a versatile valve capable of performing a multitude of functions in an effective manner. 
       BRIEF SUMMARY OF THE INVENTION 
       [0004]    A first aspect of the invention includes a valve comprising a main valve body having a first port in fluid communication with a first conduit and a second port in fluid communication with a second conduit. The valve also has a movable poppet positioned within the main valve body, the movable poppet being moveable from a first closed position in which the poppet establishes a fluid-tight seal with a sealing member, which is effective to prevent fluid flow from the first port to the second port, to a second open position in which the poppet is spaced apart from the sealing member and fluid is permitted to flow from the first port to the second port. A piezoelectric actuator is also engaged with the poppet and effective to move the poppet from the first closed position to the second open position. 
         [0005]    In an embodiment of this first aspect, the piezoelectric actuator includes a piezoelectric element coupled with an electronic cable, the electronic cable being effective to charge and discharge the piezoelectric element and cause the element to correspondingly expand or contract. The valve may also further comprise a sensor and an electronic control board, wherein the sensor is communicatively coupled with the electronic control board and the electronic control board is effective to accept readings from the sensor and issue a command causing the piezoelectric actuator to move the poppet from its first closed position to its second open position. 
         [0006]    A second aspect of the invention includes a valve comprising a main valve body having a first port, a second port, and a fluid path extending from the first to the second port. The valve has movable poppet positioned within the main valve body, the movable poppet being moveable to a plurality of different positions effective to place the fluid path in a closed, partly-open, or open state, and a piezoelectric actuator having a piezoelectric element and a frame, the frame being engaged with the poppet and effective to move the poppet amongst the plurality of different positions. A sensor is included with the valve to ascertain an environmental condition of the valve, and an electronic control board is communicatively coupled with the sensor, wherein the sensor transmits readings pertaining to the valve&#39;s environmental condition to the electronic control board, and the electronic control board is effective to accept such readings and issue a command causing the piezoelectric actuator to move the poppet from a first of its plurality of different positions to a second of its plurality of different positions. In an embodiment, the sensor is at least one of a pressure sensor, a flow sensor, and a temperature sensor. 
         [0007]    A third aspect of the invention includes a method of operating a valve comprising: (1) providing a valve having a main valve body with a first port, a second port, and a fluid path extending from the first port to the second port; (2) sensing an environmental condition of fluid flowing from the first port towards the second port by way of a sensor positioned in the main valve body; and (3) charging or discharging a piezoelectric element of a piezoelectric actuator in response to a triggering event sensed by the sensor, the charging or discharging causing a poppet engaged with the piezoelectric actuator to move between a first position in which the fluid path is sealed and a second position in which the fluid path is open or partly open. In an embodiment, the sensor is at least one of a pressure sensor, a flow sensor, and a temperature sensor, and the triggering event occurs when the sensor senses that at least one of the pressure, flow, and temperature of the fluid flowing from the inlet towards the outlet is outside of a predetermined value or range of values. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]    A more complete appreciation of the subject matter of the present invention and of the various advantages thereof can be realized by reference to the following detailed description in which reference is made to the accompanying drawings in which: 
           [0009]      FIG. 1  is a perspective, semi-transparent view of a valve according to an embodiment of the invention. 
           [0010]      FIG. 2  is an exploded, semi-transparent view of the valve of  FIG. 1 . 
           [0011]      FIG. 3  is a perspective view of a piezoelectric actuator used in the valve of  FIGS. 1-2 . 
           [0012]      FIGS. 4-5  are cross-sectional and close-up cross-sectional views of the valve of  FIGS. 1-2 . 
       
    
    
     DETAILED DESCRIPTION 
       [0013]    In describing certain aspects of the present invention, specific terminology will be used for the sake of clarity. However, the invention is not intended to be limited to any specific terms used herein, and it is to be understood that each specific term includes all technical equivalents, which operate in a similar manner to accomplish a similar purpose. 
         [0014]      FIG. 1  depicts a valve  10 , which includes a main valve body  50  having a first port  52  and another second port  54 . Depending on the mode of use, ports  52  and  54  can be used as an inlet or outlet. During use as a pressure-reduction mechanism, port  54  of valve  10  is an inlet. In a pressure-relief (or back pressure regulator) mode, port  52  of valve  10  becomes the inlet. Valve  10  includes a poppet  80  that is movable within main valve body  50  for controlling the flow of fluid into and out of ports  52 ,  54 . Main valve body  50  is also associated with an electronic control board  12  and a piezoelectric actuator  30  for controlling the movement of poppet  80 , and thus, the flow of fluid through main valve body  50 . Valve  10  can therefore act as a multi-function valve to achieve pressure relief, pressure reduction, and/or pressure regulation in a manner described in more detail below. 
         [0015]    As shown in  FIG. 2 , electronic control board  12  of valve  10  sits atop main valve body  50  and acts to control movement of piezoelectric actuator  30 . Electronic control board  12  may therefore include a variety of common electronic components, such as one or more processors, a memory, and other circuitry generally required for controlling piezoelectric actuator  30  (and thus valve  10 ), as hereinafter described. Alternatively, electronic control board  12  may be an analog component having common analog structures for controlling piezoelectric actuator  30  (and thus valve  10 ). Electronic control board  12  is connected (wirelessly or through wired means) to a sensor or transducer  56 , which in an embodiment is a pressure transducer. Other sensors/transducers may be used alone or in combination with pressure transducer  56 , such as flow sensors, temperature sensors, etc. It is to be understood that references herein to pressure transducer  56  include a variety of sensors/transducers, as described above, which may be used alone or in addition to pressure transducer  56 . 
         [0016]    Electronic control board  12  is coupled to pressure transducer  56 . In an embodiment, electronic control board  12  is configured to receive a signal from pressure transducer  56  and compare the signal to a pre-set voltage value controlled by a board-installed variable resistor. If the signal received from pressure transducer  56  is outside the set value, electronic control board  12  issues a command causing a flow condition of valve  10  to change (e.g., piezoelectric actuator  30  to move and adjust a flow condition of valve  10 ). For instance, electronic control board  12  may be configured so that a predetermined pressure reading at pressure transducer  56  causes control board  12  to issue a command or electronic signal to piezoelectric actuator  30 , thereby causing piezoelectric actuator  30  to move. In a particular embodiment, electronic control board  12  directly or indirectly causes a voltage to be applied or discharged from piezoelectric actuator  30  resulting in movement thereof. A voltage may be applied or discharged from piezoelectric actuator via its wiring/electronic cable  35 , as detailed below. In addition to autonomous operation as described above, the set voltage controlled by the adjustable resistor can be modified via a signal provided through electrical connector  13 . In this case, the variable resistor electronic loop is bypassed to give the ability to control valve  10  remotely. 
         [0017]    Referring to  FIG. 3 , piezoelectric actuator  30  includes a frame  32  having top and bottom surfaces  34 ,  36 . Frame  32 , in some cases, is composed of a metallic material. A piezoelectric element  37  is positioned inside frame  32  and, upon an electric current (e.g., a DC voltage) being applied to piezoelectric element  37 , it expands in a lateral direction as indicated by arrow  39 . In an embodiment, piezoelectric element  37  is a ceramic capacitor. Thus, once piezoelectric element  37  is charged and caused to change shape, element  37  stores energy resulting from the charge and remains in the changed shape (e.g., expanded) until discharged. Wiring/electronic cable  35  is connected to piezoelectric element  37  for charging and discharging element  37 . Likewise, an electrical connection  13  may be included with valve  10  for supplying power to piezoelectric actuator  30  and/or other components of valve  10  (e.g., electronic control board  12 ). 
         [0018]    Due to the geometry of frame  32 , lateral expansion of piezoelectric element  37  in the direction of arrow  39  results in vertical movement of frame  32  in the direction of arrow  41 . As such, vertical movement of piezoelectric frame  32  can be controlled by electronic control board  12  upon charging or discharging element  37 . Namely, when element  37  is charged it can expand and cause vertical movement of frame  32 , and when element  37  is discharged it can return to its original shape and cause frame  32  to likewise return to its original shape. As shown, the direction of arrow  41  is substantially transverse to the direction of arrow  39 . 
         [0019]    Referring to  FIGS. 2 and 4 , piezoelectric actuator  30  is constrained between separate supports  20 ,  22  within valve  10 . Each support  20 ,  22  includes a number of openings (e.g., four (4)) for accepting respective columns  18 , as well as surfaces  26  that confront the sides of piezoelectric actuator  30  to constrain it in a lateral direction. In an embodiment, the surfaces  26  of supports  20 ,  22  that confront piezoelectric actuator  30  form roughly a rectangle and constrain actuator  30  so that it is substantially fixed in all lateral directions, but is movable in the vertical direction. In this regard, columns  18  attach to main valve body  50  and extend upwards therefrom to an actuator support board  14 , which is fixed relative to body  50  in one embodiment. As shown in  FIG. 4 , support board  14  is attached to columns  18  and includes a central opening  15  for receiving a post  16 . Post  16  and opening  15  are threaded in an embodiment so that post  16  may be screwed into opening  15  and engage an opening  38  formed in top surface  34  of frame  32  of piezoelectric actuator  30 . In this way, actuator support board  14  contacts piezoelectric actuator  30  and prevents its movement upwards in the vertical direction. Because support board  14  is fixed in location and contacts piezoelectric actuator  30  via post  16 , vertical expansion of actuator  30  in a vertical direction towards support board  14  will be limited and, in some cases, prevented altogether. As such, any expansion of piezoelectric actuator  30  in the vertical direction, as hereinbefore described, results in movement of bottom surface  36  of actuator  30  in a downwards direction. Additionally, during such movement, supports  20 ,  22  and columns  18  act to guide and constrain piezoelectric actuator  30  to focus its vertical movement at a desired point. 
         [0020]    Bottom surface  36  of piezoelectric actuator  30 , as shown in  FIG. 5 , also includes a projection  42  having an opening for receiving an upwardly-extending post  46  of a disc  44 . Projection  42  contacts disc  44  and receives post  46  thereof for stability, such that movement of piezoelectric actuator  30  downwards causes movement of disc  44  in the same direction. 
         [0021]    A poppet  80  is engaged with disc  44 , as shown in  FIGS. 4-5 , such that movement of disc  44  results in movement of poppet  80 . Such movement of poppet  80  ultimately allows for operation of valve  10  and transfer of fluid therethrough, as described in more detail below. 
         [0022]    Referring to  FIGS. 4-5 , disc  44  includes a circumferential recess  47  that accepts a spring  48  for biasing disc  44  in an upwards direction. A cage retainer  58  is situated in a main vertical opening  51  in valve body  50 , which acts to support spring  48  at a bottom surface/coil thereof. Thus, spring  48  is situated within vertical opening  51  and is sandwiched between cage retainer  58  and disc  44 . As cage retainer  58  is fixed in location, and an expanded dimension of spring  48  is larger than a distance between cage retainer  58  and disc  44 , spring  48  acts to bias disk  44  upwardly so that post  46  of disc  44  remains situated in the opening of projection  42  and disc  44  contacts piezoelectric actuator  30 . 
         [0023]    Cage retainer  58  is press fit, threaded, or otherwise fixedly positioned within vertical opening  51  of valve body  50  and acts to retain a cage  60  that limits movement of poppet  80 . Cage retainer  58 , in an embodiment, is cylindrical in shape to fit within the cylindrical shape of vertical opening  51 . Cage  60  extends downwards within vertical opening  51  to a floor surface  72 , and thus, cage  60  is securely fit between floor  72  and cage retainer  58 . Cage  60  includes a cylindrical end  62  that fits within cage retainer  58  and also forms a support surface for another spring  61 . Spring  61  is supported on cylindrical end  62  of cage  60  within cage retainer  58 , and extends upwards to contact a poppet seat  90 . Poppet seat  90  has a flange  92  and a cylindrical body. Spring  61  extends around the cylindrical body to contact flange  92 . Further, poppet seat  90  is fixedly attached to poppet  80  (e.g., by press fitting, threading, welding, or another connection), such that spring  61  acts to bias poppet  80  upwardly to contact disc  44 . In particular, spring  61  acts on flange  92  of poppet seat  90  which, due to its connection with poppet  80 , causes poppet  80  to be normally urged in an upward direction. This is, again, as a result of spring  61  being sandwiched between cylindrical end  62  and flange  92  of poppet seat  90  and having an expanded dimension, which is greater than a distance between cylindrical end  62  and flange  92 . 
         [0024]    As shown in  FIG. 5 , cage  60  includes a stepped chamber for poppet  80 , and a cross-channel or opening  70  for allowing fluid to flow through cage  60  upon movement of poppet  80  into an open or partly-open position. In an embodiment, a bottom end of cage  60  also includes a seat  74  for contacting a portion of poppet  80 , and a seat retainer  76  that is threaded, press-fit, or otherwise fixedly attached within cage  60  so as to retain seat  74  in place within cage  60 . In particular, seat  74  may lie against one of the steps of the stepped chamber of cage  60 . 
         [0025]    Various seals  64  are also situated about poppet  80  and/or cage  60  at different points within main valve body  50 . Seals  64 , in one embodiment, are in the form of O-rings that establish a fluid-tight seal between the structures associated with the particular seal  64 . Thus, seals  64  act to prevent fluid travelling through or within undesired areas of valve body  50 , as described in more detail below. As an example, a seal  64  is positioned about an upper and a lower portion of cage  60  within vertical opening  51  so as to establish a fluid-tight seal between those structures. Further examples are set forth below. 
         [0026]    Still referring to  FIGS. 4-5 , poppet  80  includes an upwardly-extending post  94  that is positioned within poppet seat  90  and partially within cage  60  (e.g., its cylindrical end  62 ). A seal  64  is positioned around post  94  of poppet  80  in this area to prevent fluid from moving past seal  64  and into the area of cage retainer  58 . Likewise, a seal  64  is also positioned about cage  60  adjacent its cylindrical end  62  so that fluid cannot move towards the area of cage retainer  58  around the outside of cage  60 . This seal  64  is described in the example above as the seal  64  around the upper portion of cage  60 . Post  94  of poppet  80  is also sized so as to be able to reciprocate freely within cage  60  (e.g., its cylindrical end  62 ). 
         [0027]    Poppet  80  also has a main body  96  having one or more channels  98 . In a particular implementation, poppet  80  has two (2) channels  98  that intersect each other at an angle within main body  96 . Channels  98  are effective to allow fluid to travel from an inlet or outlet side (depending upon the mode of operation) of valve  10 , through main body  96 , and subsequently to an area  100  past main body  96 . Area  100  is additionally sealed from the main fluid pathway for valve  10  via a seal  64  positioned about main body  96  of poppet  80 , and is further sealed from the area within cage retainer  58  via a seal  64  situated about post  94  of poppet  80 . As such, fluid is able to pass from the inlet or outlet side of valve  10  and into area  100  and is effective to relieve pressure borne by poppet  80  on the inlet or outlet side (e.g., at seat  74 ). Stated differently, since fluid can travel through channels  98  and into area  100 , pressure is to some extent equalized between area  100  and the inlet side of valve  10 . As such, only a small amount of force is needed to cause downward movement of poppet  80  within vertical opening  51  in main valve body  50  since pressure between the inlet side of valve  10  and area  100  is, for the most part, equal. 
         [0028]    In use, multi-function valve  10  may be utilized for pressure reduction, pressure relief, and/or pressure regulation (e.g., when using 2 valves  10  side-by-side). In an embodiment, port  52  may be coupled to a source of fluid by way of a conduit (not shown) and port  54  may be coupled to an outlet conduit (not shown). Alternatively, as alluded to above, port  54  may be coupled to the source of fluid by way of a conduit (not shown) and port  52  may act as the outlet connected to an outlet conduit (not shown). The former configuration is used in pressure relief operations, while the latter configuration is used for pressure reduction. Valve  10  may be used in a wide range of industrial, space, or defense applications due to its high-pressure design, wide range of operating temperatures, hermetic design, and good resistance to external dynamic loads (shock and vibration). 
         [0029]    In a pressure-relief operation, fluid may be forced from the fluid source at some set pressure and be caused to enter inlet/port  52  of main valve body  50 . The fluid may encounter poppet  80 , which is sealed against seat  74 , as shown in  FIG. 4 . Thus, a fluid-tight seal is established at that area to prevent fluid from reaching port/outlet  54  through cross channel  70  of cage  60 . Meanwhile, fluid is allowed to enter into channels  98  of poppet  80  and travel to area  100  to establish an equilibrium of pressure between the inlet side of valve  10  and area  100 . In an alternate embodiment, the fluid present in area  100  may not fully equalize the pressure between area  100  and the inlet side of valve  10 , but it may lessen or mitigate the pressure differential to an acceptable degree. In this manner, poppet  80  can more freely and easily move downwards against the pressure created by the fluid source against poppet  80  in the area of seat  74 . 
         [0030]    Pressure transducer  56  acts to measure the fluid pressure created by the fluid source coupled to inlet/port  52  and simultaneously sends readings thereof to electronic control board  12  (e.g., through wireless or wired means). Again, pressure transducer  56  could alternatively or in addition include temperature or flow sensors. Electronic control board  12  may be programmable at a user&#39;s discretion so that, when a particular pressure reading is provided by pressure transducer  56 , electronic control board  12  directly or indirectly provides a particular voltage to piezoelectric actuator  30 . Alternatively, control board  12  may conversely discharge piezoelectric actuator  30  by some degree. This can cause corresponding vertical movement of frame  32  of piezoelectric actuator  30 , such that poppet  80  can be placed in an open, partly open, or closed state (e.g., as shown in  FIG. 5 ). In a particular embodiment, upon receiving a particular pressure reading (e.g., a reading that is outset a pre-set pressure value or range of values), electronic control board  12  can issue a commend that causes wiring/cable  35  of piezoelectric actuator  30  to charge or discharge actuator  30 . As an example, upon charging piezoelectric actuator  30  by some degree via wiring/cable  35 , piezoelectric element  37  can expand and cause vertical expansion of frame  32 , thereby resulting in downward movement of bottom surface  36  of actuator  30  as well as disc  44  engaged therewith. Such movement causes poppet  80  to move downwardly away from seat  74  into an open or partly-open position. As shown in  FIG. 5 , poppet  80  is spaced apart from seat  74  in the open or partly-open position to allow fluid to travel from inlet/port  52 , through the space, through channel  70  in cage  60 , and out of outlet/port  54 . 
         [0031]    Valve  10  can act as a pressure-relief or back-pressure-regulation system in that pressure transducer  56  can be programmed with an upper limit pressure value and, upon reaching that value, pressure transducer  56  sends a signal to electronic control board  12  to allow pressure relief at inlet/port  52 . Stated differently, a certain amount of fluid pressure may build up at the inlet side of valve  10  (the side of inlet/port  52 ) and, once that pressure reaches a pre-determined maximum value, as measured by pressure transducer  56 , pressure transducer  56  may send a signal to electronic control board  12  to open valve  10  by causing poppet  80  to move from a closed position against seat  74  to an open or partly-open position spaced apart from seat  74 . In this way, the pressure build up at the inlet side of valve  10  may be relieved. Such pressure build up may be a cyclical event for a certain system (e.g., pressure may build up slowly over time and periodically be relieved by way of valve  10 ). 
         [0032]    After performing a specific pressure-relief or back-pressure-regulation function, as described above, valve  10  may then be closed (where applicable) by causing poppet  80  to move upwardly and seal against seat  74 . In particular, pressure transducer  56  may send a signal to electronic control board  12 , which may then issue a command to discharge piezoelectric element  30  via wiring/cable  35 . This causes contraction of piezoelectric element  37  in a lateral direction and results in likewise contraction of frame  32  in a vertical direction, thereby ultimately moving poppet  80  upwardly against seat  74 . In an embodiment, the normal bias of poppet  80  in the upward direction via spring  61  causes poppet  80  to move upwards once downward pressure on poppet  80  from piezoelectric actuator  30  and disc  44  is withdrawn. 
         [0033]    In other configurations, as noted above, valve  10  can act as a pressure-reduction mechanism. In this configuration, port  54  acts as an inlet and port  52  acts as an outlet. In particular, inlet/port  54  may be coupled with a source of fluid and poppet  80  placed in a partly-open position to allow fluid to flow past pressure transducer  56  and out of outlet/port  52 . In this instance, pressure transducer  56  can act to maintain poppet  80  in a particular open or partly-open position to maintain an appropriate degree of fluid pressure at the outlet side of valve  10  (the side of outlet/port  52 ). For instance, if a desired degree of pressure at outlet/port  52 , as determined by pressure transducer  56 , goes out of a pre-determined range (or simply outside of a specified pressure value), pressure transducer  56  can send a signal to electronic control board  12  causing movement  80  of piezoelectric actuator  30  and corresponding movement of poppet upwards or downwards. Such movement changes the fluid pressure at outlet/port  52  back to within the desired range (or returns the pressure to the desired specific value) by altering the amount of fluid traveling from inlet/port  54  to outlet/port  52 . In other words, electronic control board  12  is operative to control the degree of openness of valve  10  to effectively regulate fluid pressure and act as a pressure-reduction mechanism. In this configuration, as with above, fluid may also be allowed to flow through main body  96  of poppet  80  via channels  98 , and to area  100 , so that pressure is somewhat equalized between inlet/port  54  and outlet/port  52  and poppet  80  is freely able to move upwards and/or downwards. 
         [0034]    In the devices depicted in the figures, particular structures are shown that are adapted for use in a valve system. The use of alternative structures for such purposes, including structures having different lengths, shapes, and configurations is also contemplated. As an example, although the valve  10  is described as being actuated in response to pressure readings, it may alternatively be actuated in different systems by any combination of pressure, temperature, and/or flow readings. For instance, if a temperature sensor is used in place of or in addition to pressure transducer  56 , the temperature sensor may act as an adjunct or substitute for pressure transducer  56 . In particular, during use as a pressure relief system, while an upward limit for pressure at the inlet side of valve  10  (the side of port  52 ) may normally trigger opening of valve  10 , the addition of a temperature sensor may establish yet another condition for opening valve  10 . In this case, not only would the pressure at the inlet side of valve  10  (the side of port  52 ) need to reach a certain level, but the temperature of the fluid at the inlet side would also need to reach a certain degree (e.g., either high or low) for valve  10  to open. Similarly, a flow sensor could be added to the system as another adjunct or alternatively a substitute. In this case as well, fluid flow as measured by the flow sensor could establish its own condition for opening or closing of valve  10 , or it may establish yet another precondition in a line of conditions that must be satisfied before valve  10  is caused to open or close. Thus, any combination of the foregoing is possible for actuation of valve  10 . 
         [0035]    Although aspects of the invention herein have been described with reference to particular embodiments, it is to be understood that these embodiments are merely illustrative of certain features of the present invention. It is therefore to be understood that numerous modifications may be made to the illustrative embodiments and that other arrangements may be devised without departing from the spirit and scope of the present invention as defined by the appended claims. For instance, the features described in connection with individual embodiments may be shared with others of the described embodiments. 
         [0036]    It will also be appreciated that the various dependent claims and the features set forth therein can be combined in different ways than presented in the initial claims. In particular, it is expressly understood that any feature provided in any dependent claim may be shared with any other claim, to the extent technologically feasible.