Abstract:
A multifunction valve includes a valve body defining an inlet, and outlet and an interior chamber. A flow control gate is disposed within the interior chamber and is rotatable through an arcuate range of positions relative to the outlet providing a high level of precision control of a fluid flow rate through the multifunction valve. A method of modulating a fluid flow rate includes directing fluid flow through a multifunction valve from an inlet to an outlet, the multifunction valve including a flow control gate, adjusting the flow rate through the multifunction valve by rotating a control shaft to position the flow control gate to variably occlude the outlet of the fluid control valve.

Description:
RELATED APPLICATIONS 
       [0001]    This application claims priority to and the benefit of U.S. Provisional Patent Application No. 62/288,620, filed on Jan. 29, 2016, the entire contents of which are hereby incorporated by reference. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention relates, generally, to fluid flow control and, more specifically, to a multifunction valve. 
         [0004]    2. Description of the Related Art 
         [0005]    Fluid control systems use a variety of valve types to turn fluid flow on and off, and also to modulate the flow rate through a fluid circuit. Conventional control systems may include valves having complex mechanisms including many components and complicated assembly. These valves may suffer from a lack of fine precision control, and require a larger volume within the fluid circuit. 
         [0006]    There remains a need for improved valves for use in fluid control systems that have a simple, compact design for a given maximum flow rate (flow rate of gas at which a reasonable drop is pressure is observed), providing easy assembly and a high precision control of flow rate. A valve which causes the least amount of pressure drop at a given flow rate can be sold to a wider range of applications, or specifically, can be used where supply pressures are lower or where packaging concerns can be overcome. 
       SUMMARY OF THE INVENTION 
       [0007]    The present disclosure overcomes the disadvantages in the related art in providing a multi-function valve simple in design and assembly, compact in size, and precise in flow rate control. 
         [0008]    In this way, a multi-function valve includes a valve body defining an inlet and an outlet, and a flow control gate disposed between the inlet and the outlet. The valve body may define an upper inlet branch and a lower inlet branch, and an interior chamber extending between the upper and lower inlet branches. The valve may also include a control shaft disposed within the interior chamber supporting the flow control gate. A radiused feature at the inlet and outlet of the valve body may provide an increased surface area at an interface with other fluid circuit components. 
         [0009]    Also disclosed herein is an improved method of fluid control. The method includes the steps of, first, directing fluid flow through a multifunction valve from an inlet to an outlet, the multifunction valve including a flow control gate, the flow control gate supported on a control shaft in an interior chamber of a valve body; and, second, adjusting the flow rate through the fluid control valve by causing a rotation of the control shaft which adjusts the position of the flow control gate to variably occlude the outlet of the multifunction valve. 
         [0010]    The radiused inlet and outlet are done also to increase open area for a given cross-section. When a filter screen is used on the design of the present disclosure, it will have more open area than a flat opening and therefore be less restrictive to the fluid flow through the filter ( FIG. 1  at 14). 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]    Other objects, includes, and advantages of the present invention will be readily appreciated as the same becomes better understood after reading the subsequent description taken in connection with the accompanying drawings, wherein: 
           [0012]      FIG. 1  shows an exemplary embodiment of a multifunction valve according to the present disclosure. 
           [0013]      FIG. 2  shows the multifunction valve of  FIG. 1  in partial cutaway view. 
           [0014]      FIGS. 3A-3C  shows multiple embodiments of a flow control gate according to the present disclosure. 
           [0015]      FIG. 4  shows an alternative embodiment of a multifunction valve according to another aspect of the present disclosure. 
           [0016]      FIG. 5  shows a second alternative embodiment of a multifunction valve according to another aspect of the present disclosure. 
           [0017]      FIG. 6  shows a representative schematic of a portion of a fluid circuit according to an aspect of the present disclosure. 
           [0018]      FIG. 7  shows a flow chart illustrating steps of a process of flow control. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0019]    With reference now to the drawings,  FIG. 1  shows an exemplary embodiment of a multifunction valve  10  according to the present disclosure, shown in an exploded view. The multifunction valve  10  includes a valve body  12  that can be installed into a fluid circuit to provide flow control. The valve body  12  facilitates fluid flow from an inlet  14  to an outlet  16 . The rate of fluid flow through the valve body is modulated by a flow control gate  18  disposed in the valve body  10  and in the fluid flow pathway between the inlet  14  and the outlet  16 . 
         [0020]    The valve body  12  defines the structure of the multifunction valve, providing an enclosure to the fluid flow pathway secure against fluid leakage and enabling the multifunction valve to be integrated into a fluid circuit. The valve body  12  may be formed from a variety of materials appropriate to the intended function of the multifunction valve, including consideration of the choice of fluid media to be communicated and the operating pressures and velocity for the fluid flow. For example, a high strength material, such as metal, may be selected to form the valve body  12  for the communication of high pressure fluids. The material of the valve body  12 , or other components of the multifunction valve  10 , may optionally be surface treated to accommodate the communication of the fluid. For example, a surface treatment may be applied to a metal valve body for the communication of a corrosive fluid, or operation in a corrosive environment. Alternatively, the valve body  12  may be formed of a ceramic material, a plastic material, a composite material or other material known in the art to be suitable for constructing valve bodies. 
         [0021]    The valve body  12  is formed through conventional fabrication processes appropriate to the material selected to form the valve body  12 . For example, a metal valve body  12  may be formed through a process of casting, forging, or machining as appropriate to create the features of the valve body  12 . The valve body  12  may be extruded and then machined as needed. Extrusion can provide a capital cost reduction over cast tooling. Additionally, extrusion may avoid common pitfalls of casting complex bodies, such as: porosity, voids, flash and cold shot. Alternatively, a plastic valve body may be formed through a molding process or a deposition process. 
         [0022]    The valve body  12  may be provided with attachment features  20  that can facilitate the mechanical retention of valve body  12  to other components in a fluid circuit (not shown). Although depicted with a series of parallel and perpendicular V-shaped and semi-circular channels, the valve body  12  may be modified to incorporate any of a variety of attachments features  20  known in the art. Alternatively, the valve body may exclude attachment features  22  and may be secured to the fluid circuit through other means, such as: welding, brazing, soldering or the like. The appropriate attachment features or securement to incorporate the valve body to the fluid circuit is selected according to knowledge and skill in the art based on the material and construction of the valve body  12 , the material of the fluid circuit components, as well as the fluid to be communicated and the operating pressure and flow rate of that fluid. The valve body  12  may also include other advantageous features to integrate with other components in a fluid circuit. Contoured exterior surfaces at the inlet  14  and the  16  maybe radiused, or curved, to increase the overall surface area at the interface between the valve by  12  and another component. When the multifunction valve  10  is used in conjunction with a filter screen at the inlet  14  or outlet  16 , this allows the surface area of the filter to be increased, thus improving filter performance and longevity, without requiring an increase in total cross-sectional area at the interface with the multifunction valve. 
         [0023]    The multifunction valve  10  also includes cover plates  22  that are secured to the valve body  12  to enclose the fluid flow pathway against communication of the fluid media outside the multifunction valve  10 . The cover plates  22  may be secured to the valve body  12  through conventional means known in the art. For example, as shown in  FIG. 1 , cover plates  22  may be secured against the top and bottom surfaces (as depicted) of the valve body  12 . Bolts or other threaded fasteners (not shown) may be provided to extend through the channels  24  and secure the cover plates  22  to the valve body  12 . Additionally, gaskets, adhesives, or other filling materials (not shown) may be provided between the cover plates  22  and the top and bottom surface of the valve body  12  to ensure a fluid-tight seal. The selection of cover plate securement is determined by those of skill in the art based on the material of the valve body as well as the fluid to be communicated and the operating pressure and flow rate of that fluid. As will be described in further detail below, one or both of the cover plates  22  may be provided with an aperture  26  for the passage of a control shaft  28 . 
         [0024]    Within the valve body  12 , the flow control gate  18  is provided to modulate the fluid flow rate through the multifunction valve  10 . The flow control gate  18  is disposed within an interior chamber  30  of the valve body  12 . The interior chamber  30  is depicted in  FIG. 1  as a generally cylindrical volume centrally disposed within the valve body  12 , although alternative structures are possible without departing from the scope of the present disclosure. The flow control gate  18  is supported within the valve body  18  by a control shaft  28 . 
         [0025]    As indicated in  FIG. 1  and shown in more detail in  FIG. 3A . The flow control gate  18  can be understood to comprise a plurality of sections. Two end sections  32 ,  34  disposed at opposite ends of the flow control gate  18  extend as tabs that can be secured to the control shaft  28 . A third section  36  of the flow control gate provides full occlusion of the outlet  16  of the valve body  12 . The full occlusion section  36  of the flow control gate  18 , when disposed adjacent to the outlet  16  completely covers the outlet  16  thereby preventing fluid from flowing through the multifunction valve  10 . A fourth section of the flow control gate  18  is a partial occlusion section  38 . The partial occlusion section  38  provides a variable amount of obstruction to the outlet  16  to reduce the flow rate through the multifunction valve  10  from a maximum, unobstructed, fluid flowrate to a terminated, fully-obstructed flow. 
         [0026]    In the exemplary embodiment, the flow control gate  18  is formed of a resilient material from a flat stock, such as a planar plastic sheet. In the alternative, the flow control gate may be formed of a metal, polymer, or other suitable material. In curving the flow control gate  18  to correspond to the surface of the interior chamber  30  of the valve body  12 , the tabs  32  and  34  can be secured to the control shaft  28  with a pin  78 , spring clip, mounting block  79 , or other mechanical means conventional in the art so that as the control shaft  28  is rotated, a corresponding rotation of the flow control gate  18  is achieved. In the embodiment depicted in  FIG. 1 , the natural resiliency of the material, in the curved configuration shown, urges the flow control gate  18  against the surface of the interior chamber  30 . 
         [0027]    The flow control gate  18  is further secured within the interior chamber against axial displacement by upper and lower retaining plates  40  and  42 . The upper and lower retaining plates  40  and  42  are annular plates configured to secure to the valve body  12 , retaining the control shaft  28  and flow control gate  18  in place within the interior chamber  30 . In the exemplary embodiment, the upper and lower retaining plates  40  and  42  include threaded portions  44  and  46 . These threaded portions  44  and  46  allow the upper and lower retaining plates  40  and  42  to be threaded into engagement with corresponding threaded portions on the valve body  12 . 
         [0028]    The upper and lower retaining plates  40  and  42  may be formed of a suitable material and by conventional means consistent with the selection of material for the valve body  12  and the intended application of the multifunction valve  10 . The upper and lower retaining plates  40  and  42  may be formed of the same materials as the valve body  12 , or alternatively may be formed of a different material. Upper and lower gaskets  50  and  52 , shown in  FIG. 2 , may also be provided at the base of the threaded portions  44  and  46  for ensuring a fluid tight seal between the upper and lower retaining plates  40  and  42  once installed. Upper and lower gaskets  50  and  52  may be provided in the shape of a torus, such as an  0 -ring, as depicted, or any other suitable gasket or mechanical seal. 
         [0029]    Further provided within the inner chamber  30  are upper and lower guide plates  54  and  56 . The upper and lower guide plates  54  and  56  create an upper and lower channels  58  and  60  between the outer edges of the guide plates  54  and  56  and the surface of the interior chamber  30  in which edges of the flow control gate  18  can be retained. The guide plates  54  and  56 , in forming the upper and lower channels  58  and  60 , provide a running and retaining surface for the flow control gate  18 . The guide plates  54  and  56  further include support apertures  55  and  57 , respectively. The support apertures  55  and  57  are centrally disposed guides for the control shaft  28 , which radially constrain the control shaft  28  while permitting axial and rotational freedom. The upper and lower guide plates  54  and  56  may be formed integrally with the upper and lower retaining plates  40  and  42 , or alternatively, may be formed as separate components from the upper and lower retaining plates  40  and  42 . 
         [0030]    Referring now to  FIG. 2 , a second view of the multifunction valve  10  is shown in partial cutaway. In the orientation shown in  FIG. 2 , the inlet  14  of the valve body  12  is oriented into the plane of the page, with the outlet  16  oriented out of the plane of the page. In operation, the multifunction valve  10  is connected in series to a fluid circuit at the inlet  14  and the outlet  16 . The fluid flowing through the multifunction valve  10  travels from the inlet  14  and is directed into an upper inlet branch  62  and a lower inlet branch  64 . The fluid then flows into the interior chamber  30  through the upper and lower retaining plates  40  and  42  and past the upper and lower guide plates  54  and  56  in to the interior chamber  30 . Finally, the fluid flows through the outlet  16  and exits the multifunction valve  10 . 
         [0031]    As described above, the flow control gate  18  is supported on the control shaft  28  in the interior chamber  30  to modulate the flow rate through the outlet  16  of the valve body  12 . The control shaft  28  is further configured to be coupled to a force controller (not shown). The force controller may include, for example, a motor, such as a stepper motor. The control shaft  28  may extend out from the valve body  12  through the aperture  26  of the cover plate  22  to engage with the force controller. In an alternative embodiment, the force controller may mount to the cover plate  22  and include a linkage extending through the cover plate  22  to engage with the control shaft  28 . In a further alternative embodiment, the cover plate  22  may be integrated as a component of the force controller, such as a motor housing. In such case, the force controller secures directly to the valve body  12 , forming a fluid tight seal and engaging the control shaft  28 . 
         [0032]    The force controller operates to rotate the control shaft  28  and thereby position the flow control gate  18  within the inner chamber  30 . Through a portion of the range of rotation, the flow control gate  18  does not cover any portion of the outlet  16 , such as is shown in  FIGS. 1 and 2 . In this configuration the fluid flow through the multifunction valve is at a maximum, unrestricted flow rate. In another configuration where the force controller has operated to position the flow control gate  18  such that the full occlusion section  36  is adjacent to the outlet  16 , the outlet  16  is fully covered and no fluid may flow through the multifunction valve  10 . In a further configuration, the force controller has operated to rotate the flow control gate  18  such that a portion of the partial occlusion section  38  is adjacent to the outlet  16 . In such manner, the fluid flow rate through the multifunction valve  10  can be finely modulated with high precision. The high level of precision control is achieved by selectively rotating the flow control  18  to occlude the desired portion of the outlet  16 . 
         [0033]    In the exemplary embodiment, the flow control gate  18  includes a constant linear slope through the partial occlusion section  38 . This embodiment is shown in its flattened from in  FIG. 3A , that is, before it has been curved to be assembled into the valve body  12 . As the flow control gate  18  is rotated through the range where the partial occlusion section  38  is adjacent to the outlet  16 , the flow rate is modulated in a linear fashion. The edge profile of the partial occlusion section determines profile of modulation. As the partial occlusion section being to cover the outlet  16 , the flow rate would begin to decrease. As the flow control gate is positioned to increasingly cover the outlet  16 , the flow rate would incrementally decrease proportionately. 
         [0034]    Alternative embodiments of the flow control gate  18  are depicted in  FIGS. 3B - and  3 C. In a first alternative embodiment as shown in  FIG. 3B , a flow control gate  65  is shown having a nonlinear slope through the partial occlusion section  66 . This nonlinear slope defines an edge profile that may provide a higher level of precision control through a mid-range of flow rates with less precision control at higher-end or lower-end flow rates. In a second alternative embodiment as shown in  FIG. 3C , a flow control gate  67  is shown having a nonlinear slope through the partial occlusion section  68  different from that of the first alternative embodiment. In this embodiment, the flow control gate  67  may provide a higher level of precision control at lower-end flow rates. 
         [0035]    Further alternative embodiments, not shown, may provide higher levels of increased precision control within specific ranges by tuning the edge profile of the partial occlusion section of the flow control gate. The tuning of the edge profile follows from the principle that a smaller increment of change in the occlusion or coverage of the outlet per an amount of rotation of the flow control gate results in more precise control. That is, for particular example, when using a stepper motor that provides a finite number of discrete steps per revolution, providing a shallower slope in the partial occlusion section of the flow control gate adjacent to the outlet at that step results in a smaller proportional change in occlusion when compared with a steeper slope. Therefore, the higher level of precision in a particular range of flow rates results from the shallower slope of the partial occlusion section. 
         [0036]    In further alternative embodiments of the present disclosure, multiple force controllers may be provided in engagement with the control shaft  28 . In one such alternative embodiment as shown in  FIG. 4 , a multifunction valve  70  includes a valve body  72  generally similar to the valve body  12 , but formed to include only one inlet branch, for example, an upper inlet branch  62 . In this embodiment, a control shaft  74  extends from the valve body  72 . A first force controller (not shown) engages the control shaft  74  to provide rotational motion to a flow control gate  18 . An additional force controller (not shown) may be provided which provides translational motion to the control shaft  74  along its longitudinal axis. A sealing disk  76  may be further provided within the valve body  12  supported on the control shaft  74  and disposed between an upper retaining plate  40  and a cover plate  22  enclosing the upper inlet branch. The second force controller may impart axial displacement to the control shaft  74  urging the sealing disk  76  against the annular upper retaining plate  40  to close the fluid flow pathway through the upper retaining plate  40 . The sealing disk  76  may be formed of a resilient material suitable for forming a seal against the upper retaining plate. In this way, the multifunction valve  70  may be provided with a secondary closing mechanism in addition to the full occlusion section  36  of the flow control gate  18  to prevent fluid flow. It is readily apparent that a single force controller capable of imparting both rotational and axial movement may be used with the multifunction valve  70 , in addition to conventional mechanical linkages disposed between the force controller and the multifunction valve  70 . In an embodiment where the control shaft translates along its axis, a spring, such as a helical spring  29 , may be provided disposed between the control shaft and the guide plate, for example, to return the control shaft to its original position once a sealing force is removed. In alternative embodiments, the spring may be omitted and the control shaft may be returned to its original position by the resiliency of the flow control gate  18 , and more specifically by the resiliency of the tabs extending as end sections of the flow control gate  18 . 
         [0037]    A further alternative embodiment of a multifunction valve  90  according to the present disclosure is shown in  FIG. 5 . The multifunction valve  90  includes the valve body  12  having the inlet  14 , and including upper and lower inlet branches  62  and  64 . Similar to the earlier described embodiment, a sealing disk  96  is supported on the control shaft  28  between the upper retaining plate  40  and a cover plate  22  (not shown). In this embodiment, a second sealing disk  92  is supported on the control shaft  28  in the interior chamber  30 . In this way, the control shaft can be positioned such that the sealing disk  96  and the second sealing disk  92  can be simultaneously urged against both the upper and lower retaining plates  40  and  42  as the sealing disks  96  and  92  move with the control shaft  28 . This seals the interior chamber  30  against both the upper and lower inlet branches  62  and  64 . Providing upper and lower inlet branches assists in maintaining a high capacity through the multifunction valve  90  and minimizes the introduction of further pressure drops as a fluid flows through the multifunction valve  90 . 
         [0038]      FIG. 6  depicts a schematic representation of a portion of a fluid circuit  80  including a multifunction valve  10 . A force controller  82 , for example a motor, solenoid, or combination thereof, is coupled to the multifunction valve  12  for actuating the multifunction valve  10  to control the fluid flow rate through the fluid circuit  80 . One or more sensors  84  and  86  may be provided in the fluid circuit upstream and/or downstream of the multifunction valve  10 . Such sensors may be selected to measure a characteristic of the fluid flow, such as flow rate, temperate, pressure, viscosity or other physical attribute. Alternatively, a secondary characteristic, or effect, resulting from the fluid flow may be measured. For example, measuring a temperature rise in a combustion process chamber (not shown) may be directly related to how much fluid (e.g., fuel) has passed through the multifunction valve. The sensors  84  and  86 , or sensors associated with combustion process chamber (if present), or other components in a fluid circuit, may be in electronic communication with a system controller  88 . The system controller  88  may include a computing device, programmable logic controller, or other system controller capable of receiving sensor signals from the sensors  84  and/or  86 , and providing actuation control to the force controller  82 . 
         [0039]    The system controller  88  is in electronic communication with the force controller  82 . The system controller  88  includes control instructions or programming that can generate instructions to direct the force controller  82  to operate the multifunction valve  10  to change the fluid flow rate by rotating the flow control gate  18  or by translating the sealing disk or disks into engagement. In some embodiments, the system controller  88  is configured to control the fluid flow rate in response to a signal from one or more sensors that an attribute of the fluid flow has deviated from a set point or set range. In alternative embodiments, the system controller may be configured to control the flow rate independent of any sensor signal, for example, according to a predetermined sequence of flow rate modulation over time. In some embodiments, the system controller  88  may be integrated with the force controller  82  as a single controller. In other embodiments, the system controller  88  and force controller  82  are separate components in electronic communication. Electronic communication between the system controller  88  and the force controller  82 , or between the sensors  84  and  86 , if present, and the system controller  88  may be achieved through wired communication, wireless communication, or a combination of wired and wireless communication, and including through one or more intermediary devices (not shown). 
         [0040]    A method  100  of modulating a fluid flow rate is depicted in  FIG. 7 . The method includes a first step  102  of sensing, at a sensor, an attribute of fluid flow through a fluid circuit. The sensor generates a sensor signal which is communicated to a system controller as the second step  104 . The system controller executes a control operation at step  106 , which is responsive to the sensor signal. The execution of the control operation generates a control signal based on previously programmed operation parameters responsive to the sensor signal at step  108  that is communicated to the force controller. Finally at step  110 , the force controller actuates in response to the control signal to adjust a flow control gate position within the multifunction valve in the fluid circuit to modulate the fluid flow rate through the fluid circuit. 
         [0041]    Alternative methods of modulating a flow rate may exclude the sensor and sensor signal, the system controller instead generating control signals based on predefined programming or instructions. In a further alternative embodiment, the system controller and the force controller are integrated as a single unit such that the sensors may communicate directly to the force controller which can respond by directly actuating the force controller to modulate the fluid flow rate. Further alternative methods of control will be readily appreciated considering the multiple embodiments described above. 
         [0042]    The invention has been described in an illustrative manner. It is to be understood that the terminology which has been used is intended to be in the nature of words of description rather than of limitation. Many modifications and variations of the invention are possible in light of the above teachings. Therefore, within the scope of the appended claims, the invention may be practiced other than as specifically described.